A Hybrid Vehicle Is a Vehicle That Uses Two Essay Example for Free

A cross Vehicle Is a Vehicle That Uses Two EssayMopeds, galvanising political machine biturns, and even electric car forfeit scooters atomic number 18 a simple form of a crown of thorns, as causation is delivered both via an internecine fire locomotive or electric go and the riders muscles. Early models of travelcycles in the late 19th speed of light theatrical role the equal principles to index number it up. * In a par e actuallyel intercrossed bicycle human and travel mogul argon mechanizedly coupled at the pedal drive train or at the get up or the front wheel, e. g. apply a hub push back, a roller pressing onto a tire, or a connection to a wheel apply a transmission element. Human and motor torques atomic number 18 added together. well-nigh all make Motorized bicycles, Mopeds ar of this eccentric. 2 * In a serial publication crown of thorns bicycle (SH) the exploiter advocators a generator utilize the pedals. This is converted into electricity and pile be fed directly to the motor liberal a chainless bicycle alone in like manner to take a bombardment. The motor draws proponent from the battery and must be able to deliver the full mechanical torque required beca social occasion n unity is forthcoming from the pedals. SH bicycles be commercially available, because they atomic number 18 very simple in theory and manufacturing.3 The maiden k promptlyn prototype and publication of an SH bicycle is by Augustus Kinzel (US Patent 3884317) in 1975. In 1994 Bernie Macdonalds conceived the Electrilite4 SH lightweight fomite which utilise strength electronics al scummying regenerative braking and pedaling while directary. In 1995 Thomas Muller designed a Fahrrad mit elektromagnetischem Antrieb in his 1995 diploma thesis and build a functional fomite. In 1996 Jurg Blatter and Andreas Fuchs of Berne University of Applied Sciences built an SH bicycle and in 1998 mounted the dodging onto a Leitra tricycle (European pa tent EP 1165188).In 1999 Harald Kutzke draw his concept of the active bicycle the aim is to speak to the ideal bicycle weighing nonhing and having no drag by electronic compensation. Until 2005 Fuchs and colleagues built several(prenominal) prototype SH tricycles and quadricycles. 5 Heavy vehicles Bus Rapid Transit of Metz, a diesel-electric loan-blendizing pretendment outline by Van Hool6 Hybrid power trains use diesel-electric or turbo-electric to power railway railway locomotives, buses, unvoiced goods vehicles, mobile hydraulic machinery, and ships.Typically most form of heat engine ( commonly diesel) drives an electric generator or hydraulic pump which powers one or much electric or hydraulic motors. there atomic number 18 advantages in distributing power through wires or pipes rather than mechanical elements especially when multiple drivese. g. driven wheels or propellers are required. There is power lost in the double conversion from mend(prenominal)ly diesel elicit to electricity to power an electric or hydraulic motor. With large vehicles the advantages often outweigh the disadvantages especially as the conversion losses typically decrease with size.With the exception of non-nuclear submarines, presently there is no or comparatively little secondary efficacy store capacity on most heavy vehicles, e. g. auxiliary batteries and hydraulic accumulatorsalthough this is now changing. Submarines are one of the oldest widespread applications of mark technology, running on diesel engines while surfaced and electric replacing to battery power when submerged. Both series- hybridisation and parallel hybrid drivetrains were employ in the Second World War. rail sour transport Main article Hybrid train East Japan Railway Company HB-E300 seriesEurope The spic-and-span Autorail a grande capacite (AGC or amply-capacity rail machine) built by the Canadian company Bombardier for service in France. This has dual mode (diesel and electric motors ) and dual voltage capabilities (1500 and 25000 V) allowing it to be used on many unlike rail systems. 7 The locomotive has been on trials in Rotterdam, the Netherlands with Railfeeding, a Genesse and Wyoming company. China The First Hybrid Evaluating prototype locomotive was designed and contracted by rail research center MATRAI in 1999 and the sample was ready in 2000.It was a G12 locomotive that was converted to hybrid by using a 200KW diesel generator and batteries and also was equipped with 4 AC traction motors (out of 4) retrofited in the coer of the DC traction motors. Japan The first operational prototype of a hybrid train engine with evidentiary naught shop and capacity re contemporaries capability was introduced in Japan as the KiHa E200. It utilizes battery packs of lithium ion batteries mounted on the capital to store recovered energy. 8North America In the U. S., General Electric introduced a prototype sandbag engine with their Ecomagination technology in 2007. Th ey store energy in a large set of atomic number 11 nickel chloride (Na-NiCl2) batteries to capture and store energy normally dissipated during dynamic braking or coasting downhill. They expect at least a 10% reduction in burn use with this system and are now spending about $2 billion/yr on hybrid research. 9 Variants of the typical diesel electric locomotive let in the Green Goat (GG) and Green Kid (GK) switching/yard engines built by Canadas Railpower Technologies.They utilize a large set of heavy duty long life (10 yr) reversible lead acid (Pba) batteries and 1000 to 2000 HP electric motors as the primary motive sources and a new clean burning diesel generator (160 Hp) for recharging the batteries that is used still as needed. No power or fuel are wasted for idlingtypically 6085% of the time for these type locomotives. It is unclear if dynamic braking (regenerative) power is recaptured for reuse but in principle it should be easily utilized.Since these engines typical need ext ra weight for traction purposes anyway the battery packs weight is a negligible penalty. In addition the diesel generator and battery package are normally built on an existing retired yard locomotives frame for significant additional constitute savings. The existing motors and running paraphernalia are all rebuilt and reused. Diesel fuel savings of 4060% and up to 80% pollution reductions are claimed over that of a typical older switching/yard engine.The same advantages that existing hybrid railroad cable cars return for use with frequent starts and stops and idle periods apply to typical switching yard use. 10 Green Goat locomotives extradite been purchased by Canadian Pacific Railway, BNSF Railway, Kansas City Southern Railway, and Union Pacific Railroad among others. Cranes Railpower Technologies engineers giveing with TSI destination Systems are testing a hybrid diesel electric power unit with battery reposition for use in Rubber Tyred Gantry (RTG) cranes.RTG cranes ar e typically used for loading and unloading shipping containers onto trains or trucks in ports and container storage yards. The energy used to lift the containers can be partially regained when they are lowered. Diesel fuel and emission reductions of 5070% are predicted by Railpower engineers. 11 First systems are expect to be operational in 2007. 12 Road transport, commercial vehicles 2008 GMC Yukon hybrid version Early hybrid systems are being investigated for trucks and other heavy highway vehicles with some operational trucks and buses starting to come into use.The main obstacles attend to be lesserer fleet sizes and the extra be of a hybrid system are except compensated for by fuel savings,13 but with the price of oil set to continue on its upward(a) trend, the tipping point whitethorn be reached by the end of 2015. dated info Advances in technology and lowered battery cost and higher(prenominal) capacity etc. developed in the hybrid car industry are already filtering into truck use as Toyota, Ford, GM and others introduce hybrid pickups and SUVs. Kenworth Truck Company recently introduced a hybrid-electric truck, called the Kenworth T270 Class 6 that for city utilisation seems to be competitive. 1415FedEx and others are starting to invest in hybrid delivery type vehiclesparticularly for city use where hybrid technology whitethorn pay off first. 16 Military off-road vehicles Since 1985, the U. S. military has been testing serial hybrid Humvees1718 and have found them to deliver faster acceleration, a stealth mode with low thermal signature/ near silent operation, and greater fuel prudence. Ships Ships with both mast-mounted sails and s police squad engines were an early form of hybrid vehicle.Another example is the diesel-electric submarine. This runs on batteries when submerged and the batteries can be re-charged by the diesel engine when the craft is on the surface. Newer hybrid ship-propulsion schemes include large towing kites manufactured by co mpanies much(prenominal) as SkySails. Towing kites can fly at heights several times higher than the tallest ship masts, capturing stronger and steadier winds. Aircraft Taxiing and other ground operations of Boeing 737NGs depart soon be done using hybrid electric drives as WheelTug ground propulsion systems become available.1920 By using the APU (powered by a turbine) to hasten a Chorus electric motor mounted in the landing gear for ground movement, distributecraft will be operating in a hybrid configuration where the main engines are used only for take off, landing, and flight. Boeing 737800 The Boeing Fuel Cell Demonstrator Airplane has a Proton Exchange Membrane (PEM) fuel carrel/lithium-ion battery hybrid system to power an electric motor, which is coupled to a conventional propeller. The fuel electric cell provides all power for the cruise phase of flight.During takeoff and climb, the flight segment that requires the most power, the system draws on lightweight lithium-ion batteries. The demonstrator aircraft is a Dimona motor glider, built by Diamond Aircraft Industries of Austria, which also carried out geomorphological modifications to the aircraft. With a wing span of 16. 3 meters (53. 5 feet), the airplane will be able to cruise at approximately 100 kilometers per hour (62 miles per hour) on power from the fuel cell. 21 Hybrid FanWings have been designed.A FanWing is earnd by two engines with the capability to autorotate and landing like a helicopter. 22 Engine type Hybrid electric-petroleum vehicles Hybrid New Flyer Metrobus Hybrid Optare Solo Main article Hybrid electric vehicle When the destination hybrid vehicle is used, it most often refers to a Hybrid electric vehicle. These encompass such vehicles as the Saturn Vue, Toyota Prius, Toyota Camry Hybrid, Ford Escape Hybrid, Toyota Highlander Hybrid, Honda Insight, Honda Civic Hybrid, Lexus RX 400h and 450h and others.A petroleum-electric hybrid most commonly uses inhering fire engines (gen erally gas or Diesel engines, powered by a variety of fuels) and electric batteries to power the vehicle. There are many types of petroleum-electric hybrid drivetrains, from Full hybrid to Mild hybrid, which offer varying advantages and disadvantages. 23not in deferred payment given Henri Pieper in 1899 developed the first petro-electric hybrid automobile in the world.In 1900, Ferdinand Porsche developed a series-hybrid using two motor-in-wheel-hub ar commitments with a fire generator set providing the electric power, setting two speed recordscitation needed. maculation liquid fuel/electric hybrids date back to the late 19th century, the braking regenerative hybrid was invented by David Arthurs, an electric engineer from Springdale, Arkansas in 197879. His home-converted Opel GT was reported to return as much as 75MPG with plans still exchange to this original design, and the Mother Earth News modified version on their website.24 The plug-in-electric-vehicle (PEV) is becoming more and more common. It has the range needed in locations where there are wide gaps with no services. The batteries can be out of use(p) into house (mains) electricity for charging, as well being charged while the engine is running. Continuously out get on with recharged electric vehicle (COREV) Given suitable infrastructure, permissions and vehicles, BEVs can be recharged while the user drives. The BEV establishes contact with an electrified rail, place or overhead wires on the highway via an attached conducting wheel or other similar mechanism (see Conduit current collection).The BEVs batteries are recharged by this processon the highwayand can then be used normally on other roads until the battery is discharged. Some of battery-electric locomotives used for maintenance trains on the capital of the United Kingdom Underground are capable of this mode of operation. Power is picked up from the electtrified rails where possible, switching to battery power where the electricity su pply is disconnected. This provides the advantage, in principle, of virtually unrestricted highway range as long as you stay where you have BEV infrastructure access.Since many destinations are within 100 km of a major(ip) highway, this may reduce the need for expensive battery systems. Unfortunately private use of the existing electric system is nearly universally prohibited. The technology for such electrical infrastructure is old and, outside of some cities, is not widely distributed (see Conduit current collection, trams, electric rail, trolleys, third rail). Updating the required electrical and infrastructure costs can be funded, in principle, by toll revenue, gasoline or other taxes. Hybrid fuel (dual mode).Ford Escape Hybrid with a flexible fuel capability to run on E85 (ethanol) In addition to vehicles that use two or more different devices for propulsion, some also consider vehicles that use distinct energy sources or input types (fuels) using the same engine to be hybrids , although to avoid muddiness with hybrids as described above and to use correctly the terms, these are perhaps more correctly described as dual mode vehicles * Some electric trolleybuses can switch between an on board diesel engine and overhead electrical power depending on conditions (see dual mode bus).In principle, this could be have with a battery subsystem to create a true plug-in hybrid trolleybus, although as of 2006, no such design seems to have been announced. * Flexible-fuel vehicles can use a sort of input fuels mixed in one tank typically gasoline and ethanol, or methanol, or biobutanol. * Bi-fuel vehicleLiquified petroleum gas and cancel gas are very different from petroleum or diesel and cannot be used in the same tanks, so it would be impossible to build an (LPG or NG) flexible fuel system.Instead vehicles are built with two, parallel, fuel systems feeding one engine. For example Chevys Silverado 2500 HD, which is now on the road, can effortlessly switch between petroleum and natural gas, and offers a range of over 650 miles. 25 While the duplicated tanks cost space in some applications, the increased range, decreased cost of fuel and flexibility where (LPG or NG) infrastructure is incomplete may be a significant incentive to purchase. While the U. S.Natural gas infrastructure is partially incomplete, it is change magnitude at a fast pace, and already has 2600 CNG stations in place. 26 With a growing fueling station infrastructure, a large scale adoption of these bi-fuel vehicles could be seen in the near future. Rising gas prices may also push consumers to purchase these vehicles. When gas prices trade around $4. 00, the price per MMBTU of gasoline is $28. 00, compared to natural gass $4. 00 per MMBTU. 27 On a per unit of energy comparative basis, this makes natural gas much cheaper than gasoline. totally of these factors are qualification CNG-Gasoline bi-fuel vehicles very agreeable. * Some vehicles have been modified to use another fu el source if it is available, such as cars modified to run on autogas (LPG) and diesels modified to run on waste vegetable oil that has not been processed into biodiesel. * Power-assist mechanisms for bicycles and other human-powered vehicles are also included (see Motorized bicycle). Fluid power hybrid Chrysler minivan, petro-hydraulic hybrid French MDI petro-air hybrid car developed with Tata.Hydraulic and pneumatic hybrid vehicles use an engine to charge a pressure accumulator to drive the wheels via hydraulic or pneumatic (i. e. savourless air) drive units. In most cases the engine is detached from the drivetrain merely only to change the energy accumulator. The transmission is seamless. Petro-air hybrid A French company, MDI, has designed and has running models of a petro-air hybrid engine car. The system does not use air motors to drive the vehicle, being directly driven by a hybrid engine. The engine uses a mixture of compressed air and gasoline injected into the cylinders.2 8 A key aspect of the hybrid engine is the active chamber, which is a compartment heating air via fuel doubling the energy output. 29 Tata Motors of India assessed the design phase towards full production for the Indian market and moved into completing detailed development of the compressed air engine into specific vehicle and stationary applications. 3031 Petro-hydraulic hybrid Petro-hydraulic configurations have been common in trains and heavy vehicles for decades. The auto industry recently think on this hybrid configuration as it now shows promise for introduction into little vehicles.In petro-hydraulic hybrids, the energy recovery rate is high and therefore the system is more effective than battery charged hybrids using the current battery technology, demonstrating a 60% to 70% increase in energy economy in U. S. Environmental shield Agency (EPA) testing. 32 The charging engine needs only to be sized for ordinary usage with acceleration bursts using the stored energy in th e hydraulic accumulator, which is charged when in low energy demanding vehicle operation. The charging engine runs at optimum speed and load for efficiency and longevity. Under tests undertaken by the U.S. Environmental testimonial Agency (EPA), a hydraulic hybrid Ford Expedition returned 32 miles per US gallon (7. 4 L/100 km 38 mpg-imp) City, and 22 miles per US gallon (11 L/100 km 26 mpg-imp) highway. 3334 UPS currently has two trucks in service with this technology. 35 Although petro-hybrid technology has been known for decades, and used in trains and very large construction vehicles, heavy costs of the equipment precluded the systems from lighter trucks and cars. In the modern sense an experiment turn out the viability of small petro-hybrid road vehicles in 1978.A group of students at Minneapolis, Minnesotas Hennepin Vocational Technical Center, converted a Volkswagen Beetle car to run as a petro-hydraulic hybrid using off-the shelf components. A car rated at 32mpg was returni ng 75mpg with the 60HP engine replaced by 16HP engine. The observational car reached 70 mph. 36 In the 1990s, a team of engineers working at EPAs National Vehicle and Fuel Emissions Laboratory succeeded in developing a revolutionary type of petro-hydraulic hybrid powertrain that would propel a typical American sedan car. The test car achieved over 80 mpg on combined EPA city/highway driving cycles.Acceleration was 0-60 mph in 8 seconds, using a 1. 9 liter diesel engine. No lightweight materials were used. The EPA estimated that produced in high volumes the hydraulic components would add only $700 to the base cost of the vehicle. 34 While the petro-hydraulic system has faster and more efficient charge/discharge cycling and is cheaper than petro-electric hybrids, the accumulator size dictates total energy storage capacity and may require more space than a battery set. Research is underway in large corporations and small companies. Focus has now switched to smaller vehicles.The system components were expensive which precluded installation in smaller trucks and cars. A drawback was that the power driving motors were not efficient enough at part load. A British company has do a breakthrough by introducing an electronically controlled hydraulic motor/pump, the Digital Displacement motor/pump, that is highly efficient at all speed ranges and loads fashioning small applications of petro-hydraulic hybrids feasible. 37 The company converted a BMW car as a test bed to prove viability. The BMW 530i, gave double the mpg in city driving compared to the standard car.This test was using the standard 3,000cc engine. Petro-hydraulic hybrids using well sized accumulators entails downsizing an engine to average power usage, not peak power usage. Peak power is provided by the energy stored in the accumulator. A smaller more efficient constant speed engine reduces weight and liberates space for a big accumulator. 38 Current vehicle bodies are designed around the mechanicals of existing engine/transmission setups. It is restrictive and outlying(prenominal) from ideal to install petro-hydraulic mechanicals into existing bodies not designed for hydraulic setups.One research projects goal is to create a blank paper design new car, to maximize the packaging of petro-hydraulic hybrid components in the vehicle. All bulky hydraulic components are integrated into the chassis of the car. One design has claimed to return 130mpg in tests by using a large hydraulic accumulator which is also the structural chassis of the car. The small hydraulic driving motors are incorporated within the wheel hubs driving the wheels and reversing to claw-back energizing braking energy. The hub motors eliminates the need for friction brakes, mechanical transmissions, drive shafts and U joints, reducing costs and weight.Hydrostatic drive with no friction brakes are used in industrial vehicles. 39 The aim is 170mpg in average driving conditions. Energy created by stroke absorbers and k inetic braking energy that normally would be wasted assists in charging the accumulator. A small fossil fuelled speculator engine sized for average power use charges the accumulator. The accumulator is sized at running the car for 15 minutes when fully charged. The aim is a fully charged accumulator with an energy storage potential of 670 HP, which will produce a 0-60 mph acceleration speed of under 5 seconds using four wheel drive.404142 In January 2011 industry giant Chrysler announced a partnership with the U. S. Environmental Protection Agency (EPA) to design and develop an experimental petro-hydraulic hybrid powertrain suitable for use in large passenger cars. In 2012 an existing production minvan will be adapted to the new hydraulic powertrain. 34434445 PSA Peugeot Citroen exhibited an experimental Hybrid Air engine at the 2013 Geneva Motor Show. 46 The vehicle uses nitrogen gas compressed by energy harvested from braking or deceleration to power an hydraulic drive which sup plements power from its conventional gasoline engine.The hydraulic and electronic components were supplied by Robert Bosch GmbH. Production versions priced at about $25,000, ? 17,000, are scheduled for 2015 or 2016. gas mileage was estimated to be about 80 miles per gallon for city driving if installed in a Citroen C3. 47 Electric-human power hybrid vehicle Another form of hybrid vehicle are human power-electric vehicles. These include such vehicles as the Sinclair C5, Twike, electric bicycles, and electric skateboards. Hybrid vehicle power train configurations Main articles Hybrid vehicle drivetrains and small HEV.Parallel hybrid Honda Insight, Mild Parallel Hybrid Toyota Prius, series-parallel hybrid Ford Escape Hybrid, a series-parallel drivetrain In a parallel hybrid vehicle, the single electric motor and the internal combustion engine are installed such that they can power the vehicle either individually or together. In contrast to the power split configuration typically only one electric motor is installed. Most commonly the internal combustion engine, the electric motor and gear box are coupled by automatically controlled clutches.For electric driving the clutch between the internal combustion engine is open while the clutch to the gear box is engaged. While in combustion mode the engine and motor run at the same speed. The first mass production parallel hybrid sold outside Japan was the 1st generation Honda Insight. Mild parallel hybrid These types use a generally compact electric motor (usually 20 kW) to provide auto-stop/start features and to provide extra power assist48 during the acceleration, and to generate on the deceleration phase (aka regenerative braking).On-road examples include Honda Civic Hybrid, Honda Insight 2nd generation, Honda CR-Z, Honda Accord Hybrid, Mercedes Benz S400 BlueHYBRID, BMW 7-Series hybrids, General Motors BAS Hybrids, and Smart fortwo with micro hybrid drive. Power-split or series-parallel hybrid Passenger car install ations include Toyota Prius, Ford Escape and Fusion, as well as Lexus RX400h, RX450h, GS450h, LS600h, and CT200h. In a power-split hybrid electric drive train there are two motors an electric motor and an internal combustion engine.The power from these two motors can be shared to drive the wheels via a power splitter, which is a simple planetary gear set. The ratio can be from 0100% for the combustion engine, or 0100% for the electric motor, or anything in between, such as 40% for the electric motor and 60% for the combustion engine. The electric motor can act as a generator charging the batteries. youthful versions such as the Toyota Hybrid Synergy Drive have a second electric motor/generator on the output shaft (connected to the wheels).In cooperation with the primary motor/generator and the mechanical power-split this provides a perpetually variable transmission. On the open road, the primary power source is the internal combustion engine. When utmost power is required, for ex ample to overtake, the electric motor is used to assist. This increases the available power for a short period, giving the effect of having a larger engine than actually installed. In most applications, the engine is switched off when the car is slow or stationary reducing curbside emissions. Series hybrid Chevrolet Volt, series plug-in hybrid.Honda Civic Hybrid used by Zipcar car sharing service Ford Escape plug-in hybrid A series- or serial-hybrid vehicle has also been referred to as an Extended Range Electric Vehicle or Range-Extended Electric Vehicle (EREV/REEV) nevertheless, range extension can be accomplished with either series or parallel hybrid layouts. Series-hybrid vehicles are driven by the electric motor with no mechanical connection to the engine. Instead there is an engine tuned for running a generator when the battery pack energy supply isnt sufficient for demands. This arrangement is not new, being common in diesel-electric locomotives and ships.Ferdinand Porsche us ed this setup in the early 20th century in racing cars, effectively inventing the series-hybrid arrangement. Porsche named the arrangement System Mixt. A wheel hub motor arrangement, with a motor in each of the two front wheels was used, setting speed records. This arrangement was sometimes referred to as an electric transmission, as the electric generator and driving motor replaced a mechanical transmission. The vehicle could not move unless the internal combustion engine was running. The setup has never proved to be suitable for production cars, however it is currently being revisited by several manufacturers.In 1997 Toyota released the first series-hybrid bus sold in Japan. 49 GM introduced the Chevy Volt EREV in 2010, aiming for an all-electric range of 40 miles,50 and a price tag of around $40,000. 51 Supercapacitors combined with a lithium ion battery bank have been used by AFS Trinity in a converted Saturn Vue SUV vehicle. Using supercapacitors they claim up to 150 mpg in a s eries-hybrid arrangement. 52 Plug-in hybrid electric vehicle (PHEV) Main article Plug-in hybrid Another subtype added to the hybrid market is the Plug-in Hybrid Electric Vehicle (PHEV).The PHEV is usually a general fuel-electric (parallel or serial) hybrid with increased energy storage capacity (usually Li-ion batteries). It may be connected to mains electricity supply at the end of the journey to avoid charging using the on-board internal combustion engine. 5354 This concept is attractive to those seeking to minimize on-road emissions by avoiding or at least minimizing the use of spyglass during daily driving. As with pure electric vehicles, the total emissions saving, for example in CO2 terms, is dependent upon the energy source of the electricity generating company.For some users, this type of vehicle may also be financially attractive so long as the electrical energy being used is cheaper than the petrol/diesel that they would have otherwise used. Current tax systems in many European countries use mineral oil gross as a major income source. This is generally not the case for electricity, which is taxed uniformly for the domestic customer, however that somebody uses it. Some electricity suppliers also offer price benefits for off-peak night users, which may further increase the drawing card of the plug-in option for commuters and urban motorists. Fuel cell, electric hybrid.The fuel cell hybrid is generally an electric vehicle equipped with a fuel cell. The fuel cell as well as the electric battery are both power sources, making the vehicle a hybrid. Fuel cells use hydrogen as a fuel and power the electric battery when it is depleted. The Chevrolet Equinox FCEV, Ford Edge Hyseries Drive and Honda FCX are examples of a fuel cell/electric hybrid. Road safety for cyclists, pedestrians A 2009 National Highway art Safety Administration report examined HEV accidents that involved pedestrians and cyclists and compared them to accidents involving combustion-en gine vehicles.The findings showed that, in certain road situations, HEVs are more solemn for those on foot or bicycle. For accidents where a vehicle was slowing or stopping, backing up, entering or leaving a parking space (when the sound difference between HEVs and CEVs is most pronounced), HEVs were twice as likely to be involved in a pedestrian crash than CEVs. For crashes involving cyclists or pedestrians, there was a higher incident rate for HEVs than CEVs when a vehicle was turning a corner. But there was no statistically significant difference between the types of vehicles when they were driving straight.55 Environmental issues Fuel consumption and emissions reductions The hybrid vehicle typically achieves greater fuel economy and lower emissions than conventional internal combustion engine vehicles (ICEVs), resulting in fewer emissions being generated. These savings are primarily achieved by three elements of a typical hybrid design 1. relying on both the engine and the elec tric motors for peak power needs, resulting in a smaller engine sized more for average usage rather than peak power usage. A smaller engine can have less internal losses and lower weight.2. having significant battery storage capacity to store and reuse recaptured energy, especially in stop-and-go traffic typical of the city driving cycle. 3. recapturing significant amounts of energy during braking that are normally wasted as heat. This regenerative braking reduces vehicle speed by converting some of its kinetic energy into electricity, depending upon the power rating of the motor/generator Other techniques that are not necessarily hybrid features, but that are frequently found on hybrid vehicles include 1.using Atkinson cycle engines instead of Otto cycle engines for improved fuel economy.2. shutting down the engine during traffic stops or while coasting or during other idle periods. 3. improving aerodynamics (part of the reason that SUVs get such bad fuel economy is the drag on th e car. A box shaped car or truck has to exert more force to move through the air causing more stress on the engine making it work harder). Improving the shape and aerodynamics of a car is a good way to suffice better the fuel economy and also improve handling at the same time.4. using low peal resistance tires (tires were often made to give a quiet, smooth ride, high grip, etc. , but efficiency was a lower priority). Tires cause mechanical drag, once again making the engine work harder, consuming more fuel. Hybrid cars may use special tires that are more inflated than regular tires and stiffer or by choice of carcass structure and rubber compound have lower rolling resistance while retaining acceptable grip, and so improving fuel economy whatever the power source.5. powering the a/c, power steering, and other auxiliary pumps electrically as and when needed this reduces mechanical losses when compared with driving them continuously with traditional engine belts. These features mak e a hybrid vehicle particularly efficient for city traffic where there are frequent stops, coasting and idling periods. In addition noise emissions are reduced, particularly at idling and low operating speeds, in comparison to conventional engine vehicles.

Family theories Essay Example for Free

Family theories EssayIn this service, I am going to discuss about the conjugal kind in ultra unexampled industrial societies. This nitty-gritty I will assess the take on that conjugal relationships be based on equating in recent industrial societies. I plan to structure my answer from housework and childcargon, power and money servicemanagework forcet. The hours worked between husband and wife become more equal by the increased participation by wo manpower in the labour market have led to more equivalence in modern family sustenance.This view is highly supported by many sociologists like young and Willmott who refer that the family is change state more symmetrical and therefore, is in fact becoming more egalitarian via a treat of progress. They suggest that the family is gradually improving in terms of equality as there has been a burn away from segregated conjugal roles and more of a happy chance towards joint ones.This they argue is ascribable to study soci al changes in that women be more financially dependant with employment opportunities and so there is tiny of a need to rely on extended kin. This is further explained by Gershuny who suggests that because women have these employment opportunities, they are more likely to do less domestic work. This is shown by the item as it suggests that men were making more of an effort to do housework when their wives were in full-time employment.By this change of position for women, it has meant that men are now more responsible for different household tasks therefore suggesting that equality within modern family brio is unmistakable and so this view seems correct. He emphasises the change in social values as a reason for this which is also supported by Sullivans study (2000) which found an increase in equal division of labour. This supports Young and Willmotts march of progress view that conjugal roles are becoming more symmetrical therefrom suggesting that the view of equal sex roles a nd relationships is likely.Also, due to post-modern ordering, there are ameliorate living conditions compared to those during industrial enterprise and so this has drawn the men back into the family and thus has enabled them to help with housework and childcare as wellhead as providing leisure time enhancing equality in relationships. The social changes have meant that equality is becoming evident and so the statement seems highly likely. However, the functionalist view of equality in modern family life has been highly criticised particularly by feminists like Ann Oakley (1974).Oakley rejects the March of progress view described by Young and Willmott as she suggests that this is simply exaggerated as we subdued live in a patriarchal society where women do most of the housework. She suggested that the methodology used by Young and Willmott was hardly convincing as their questions lacked in detail. In Oakleys research, she found unaccompanied 15% of husbands had a high particip ation in housework, screening how the statement is flawed as this clearly does not show evidence of equality in relationships and gender roles.Despite Gershuny suggesting that paid work entitled equality for women, Oakley suggested that this was only an extension of the housewife role. Therefore, unlike Parsons claim of a natural role, feminists argue that this was socially constructed to enforce dependence on men which became worse with industrialisation as it forced women to stay within the home. Thus, it is clear that joint conjugal roles are not as joint as functionalists initially suggested they were as the social changes have only exacerbated the role of women suggesting this so called equality does not exist.Besides, other feminists like Elsa Ferri and Kate Smith (1996) suggest that the changed position of women in terms of employment has only created a dual burden as they now have to undertake paid work as well as the unpaid housewife role. Ferri and Smith suggest that unli ke Gershuny, increased employment has had little impact of the domestic labour as fewer than 4% of families had a father responsible for childcare. Therefore, women electrostatic remain responsible for the children as well as their employment responsibility clearly suggesting that modern family life is not as equal as it seems.The dual burden is also supported by Dunscombe and Marsdens theory of a triple burden in that women are expected to do the double shift of housework and paid work but also the caring of the emotional welfare of the family. This clearly disputes Gershunys idea that women are more equal due to employment as the triple burden means that they in fact gain more responsibilities than losing them. Next, feminists point to inequalities of power and control that persist in modern family relationships as a key reason for inequality again challenging the statement.Allan suggests that ideological factors limit womens power in that they are disadvantaged from the start. This suggests that the family is always going to be founded on inequality thus suggesting that the view of equality is limited. This is supported by Barrett and McIntosh who suggest that men gain far more from womens domestic work than they give in financial support and that in turn this support lots comes with strings attached. Also, men are usually the ones who make decisions about finances despite more or less families cosmos dual-earners.This is due to the fact that women are statistically still paid on average less than men enhancing male economic power. Therefore you can question the extent of equality in modern family life. Resources are also said to be shared unequally like Kempsons (1994) study among low-income families. This leaves women in mendicancy and so restricts their power in the family which creates an atmosphere of inequality in conjugal relationships. This is further explained by feminists Pahl and Vogler (1993) who think on the effects of decision making wi thin the family through ideas like pooling and allowance systems.They found a 31% increase in pooling where both(prenominal) partners have joint decision responsibility as well as a decline in allowance systems. However, it was still evident that men usually do huge financial decisions. Edgell also supports this as the levels of decision making are not equal due to the male economic power that still exists. Therefore, women have less say in the decisions and thus it is perspicuous that the view that gender roles and relationships are becoming more equal is incorrect as inequality in pay and decisions still exist.Similarly, this inequality of power has led to domestic violence which clearly shows how inequality is evident in that relationships are being gender dominated. Radical feminists like Millett and Firestone (1970) use domestic violence as a way to show that society is primarily founded on patriarchy and that men oppress and form women. They suggest that the inequality of power within the family maintains mens power and so domestic violence is inevitable.Similarly, Dobash and Dobash suggest that marriage legitimises violence against women as it provides the male with power and the women with dependency, therefore evidently showing no signs of equality. Thus, this disputes the statement of gender roles and relationships becoming more equal with 1 in 4 women being assaulted in their lifetime according to Mirrlees-Black. Finally, childcare which is essentially about exercising responsibility for another person who is not fully responsible for herself and it entails seeing to all aspects of the childs security and well-being,her growth and development at any and all times. Mary Boulton ( 1983 ) argues the exaggeration in the extent of mens involvement in childcare and she denies that questions about who does what give a true picture of conjugal roles. She also claims that although men capacity help with particular tasks, it is their wives who retain pr imary responsibility for children. It is the wives who relegate non-domestic aspects of their lives to a low priority. This shows that there is still inequality in terms of childcare in conjugal relationships.In addition, Elsa Ferri and Kate Smith provide some empirical support for Boulton by conducting a study based on National Child training Survey. The survey found it was still very rare for fathers to take primary responsibility for childcare. In both the sample of mothers and the sample of fathers it was very rare in dual-earner families, no-earner families or families where only the mother worked, for the man to be normally responsible for the children or to look after them when they were ill.In almost every category the man was the main carer in 4 percent or less of families. This is also supported by the innate feminist idea of gender scripts in that there are expected norms in terms of gender roles and so patriarchal relationships are inevitable. Therefore, they suggest t hat equality without burdens will only be reached through same-sex relationships as this eliminates the gender script idea.Thus, this enhances the inequality of the family, and suggests that the view that conjugal relationships are becoming more equal is in fact incorrect as the inevitability of patriarchal relationships means that equality cannot be established. In conclusion, I have discussed and assessed the view that conjugal relationships are based on equality in modern industrial societies by evaluating three sections which are hours worked, power and childcare. With all of the statement, I believe that conjugal relationships in modern industrial societies are not based on equality.

Tilting Trains Essay Example for Free

Tilting Trains EssayThe directing involved in TILTING TRAIN is that when ever the shoot fors pass over the curves and turnings of the pathway tracks the compartments of the train is mongered to a certain angle by which the trains erect travel with no reduction in go. By adopting this technology of TILTING TRAINS the fuel consumed by the trains can be saved ,the riders can witness comfort and also clip can be saved. CONTENTS 1. Introduction 2. Problem with corners 3. What is tilting train? 4. Why tilting helps? 5. How do trains tilt? 6. Problems associated in tilting the track 7. Passenger comfort ness 8. Countries who authentic the tilting technology 9. Advantages and Disadvantages of tilting trains 10. Summary 11. Bibliography INTRODUCTION Train is a mass transporter, which transports humans and goods from one place to another place. We have trains, which run by diesel and electricity. Among goods and passenger trains the most concerned one is passenger trains. The p assenger train should move quickly with racy reanimates.The rail road leave behind not be always straight it should pass through curves and turns. We exclusively experience that if you ar driving in your simple machine and you take a turning at speed you feel come out of the closetward-moving vehemences. Well it is no several(predicate) from trains, if a train takes a turning at speeds centrifugal forces result be experienced. The major problem for any trains is to pass over the curves and turns of the railroads. If the train moves with the same speed at the curves and turns the train may slip ones mind from the track, so the speed of the train bequeath be subnormality drastically to avoid slip.This results in wastage of fuel and in turn reduces the speed of the train, which is main consideration for the passenger trains. unrivaled of the solution found to avoid this situation is the tilting trains. PROBLEMS WITH CORNERS We all know that if your driving in your rail car and you take a corner at speed you feel centrifugal forces. Well it is no different from trains if a train takes a corner at speed because centrifugal forces come in. a lot train operating companies face a decision for building a mellowed speed rail personal credit line transport system hey can either invest money in the train to make it tilt b arly use existing rail line lines, or they invest money in a untried railway just dont need to spend money on expensive tilting mechanisms. This is why TGV, and ICE and roll of tobacco trains do not tilt, be causation they have their own dedicated spicy speed railway lines where curves are construct with very high radii. It is worth phaseing out that the centrifugal force is a function of v2/r where v is the velocity and r is the radius. This means if you double the velocity, you quadruple the centrifugal force.Similarly, if you want to triple the velocity but keep the centrifugal force the same, you must increase the radius by a factor of cabaret Some topic not always possible. This is why even apparently gentle curves can be much to a greater extent of a problem with high speeds than one might thing, because the force rises with the square of velocity. WHAT IS TILTING TRAIN ? Tilting train consists of a tilting mechanism that enables increased speed on regular tracks. In the upper part of the tilting trains that is in which the passengers are seated can be tilted sideways.During the motion of the train if the train has to steer to left in a left turning the coaches of the train leave be tilted to the left in magnitude to compensate the centrifugal energy to the right and conversely during the right turn. These trains are constructed such that inertial forces which cause the tilting can be controlled by a com set aparter. If the trains travel at speeds more than the specified speeds at the turnings of the railway tracks their will be centrifugal forces acting on the train. Due to these centrifugal forces the train may slip and push out of the tracks.But in case of tilting trains which will not happen, because of the reason that centrifugal forces will be compensated by tilting mechanism. WHY TILTING HELPS? When sitting on a corner going at speed in that location are cardinal forces acting on you, gravitational force and the centrifugal force which is accelerating you into the corner. In physics when two forces act, hence this causes a resultant force. The resultant force will push you into your seat and to the side. However if the train is tilting, then the normal get through force of you on your seat will be the same as the resultant force you are experiencing.This means as removed as the passenger is concerned he or she is just being pulled into his or her seat, and he or she is employ to that so no discomfort is felt. This is true also of aero compresseds, commercial planes tilt a large amount, up to 30 degrees when going near corners in some cases to cater for pas senger comfort. As the tilting of the aero plane is to prepare rid of the problem of centrifugal forces, or more accurately to disguised the centrifugal forces as a part of gravity as far as the passengers are concerned. The only way you know if the aero plane is tilting is to look out of the window.Trains that tilt can go up to 25% to 40% faster around curves than conventional trains without upsetting the passengers, and as mentioned before this can significantly increase average speeds and cut jaunt times. HOW DO TRAINS TILT? Carriages have tilting mechanisms. Obviously the bogies cannot tilt because they ride on the track and must conserve the path of the track. So the coaches have to tilt on the bogies. The way they do this is simple, the bogie acts a fulcrum in the center and it is free to tilt either side. Then pistons control how much the coach tilts. The pistons are controlled by a small computer, which uses a spirit level.The spirit level is used to check if things are swimming remember, i. e. at right angles to the resultant force acting. Normally this force is gravity, but when going round a corner the resultant is a combination of gravity and centrifugal forces. This means the spirit level indicates it is no longer horizontal, so the computer adjusts the pistons until horizontal is read. Again this will not be horizontal to the ground, but as far as anyone on the train is concerned it will be horizontal, keeping the passengers happy. In the beforehand(predicate) days they tried to use inertial force to let the trains tilt i. e. hey would have no mechanism to make them tilt but the carriages would have a low center of gravity so centrifugal forces on the carriage would cause them to tilt. This proved unsuccessful. PROBLEMS ASSOCIATED IN TILTING THE TRACK Well on high speed lines the track in the UK is heavily banked up on corners, although going in a high speed train you dont notice it at all. Occasionally when a high speed train in the UK come s to a stop because of a red signalise or something on a curve you can really notice how much its slanted, on a stop on a curve put a bottle on the floor and will slide crossways to the other side.However there are limitations with tilting tracks, first of all the banking has to be designed with a specific speed in mind. A banked up track meant for 125mph trains is going to cause discomfort to passengers in a local 75mph train, as when a slower train goes round a banked corner it will make passengers feel like they are falling to a side. Of course you could build dedicated high speed lines, but then you would engineer them without soused curves. This limits the extent to which tracks can be banked up. If the rack is banked too much for really fast trains, then if any train comes to a stop on the curve due to a red signal the slant will cause discomfort to passengers. Also arranging for the overhead pantrograph to make proper contact with a wire above a banked curve is a little tr icky. Clearly trains themselves need to tilt, then you get the double benefit of tilted track and tilting train, and the train can tilt to exactly admit the speed it is going at. PASSENGER COMFORTNESS One might think it is not safe to push a train round a corner at high speed. Indeed that is true. However the crucial thing is that the speed at which it becomes unsafe, i. . the speed at which there is enough force to push the train mangle the track is incredibly high. In fact the force needed would be enough so that all passengers on the train couldnt move and would be stuck to the sides of the train. This implies that there is scope for increasing the speed of a train round corners a great deal without it becoming unsafe, however passengers will object. There are two reasons why it is bad for passengers. I have been on a late running Inter city 125 and it took a corner at some speed although only about 90mph and the corner wasnt tight enough to say see the train at the other end by looking out of the window.The corner wasnt tight enough to notice turning either. However you could feel the forces definitely, and empty cups rolled across tables, bags creaked and I felt pushed against the wall. Any faster and it would be extremely uncomfortable for passengers and they would rather the train slowed tweak and take a little longer. Also companies dont like to run trains at speed round corners because it upsets passengers, as when exposed to turning forces they may become worried the train is going to fly off the tracks (which well-timed has never happened). This might make people nervous about traveling on high speed trains.The reason no one is ever nervous about traveling at nearly 200mph on a train is because it is smooth and constant. If it was doing corners at these speeds people wouldnt like it. People get freaked out doing 50mph on a roller coaster which involves tight curves, imagine how they feel when serious speed is involved Its all calibrate to the forces a passenger feels, if a passenger feels a lot of strong forces then he or she is going to be nervous, and may avoid traveling on the train, or just choose a slow train. COUNTRIES WHO DEVELOPED THE TILTING TECHNOLOGY BritainThe UK was interested in developing the advanced passenger train for quite a while France The development of the tilting train in France began in 1956 when eng. Mauzin built and experimented a single car unit that used inertial (non-assisted) tilting. This experiment were suspended because a natural tilting proved too concentrated to accomplish. France preferred to built a vast network of high speed lines and the development of TGV started in the early seventies with a two-car modified turbo train. Today GEC-Alsthom has decided to start the development of a tilting TGV that has been delivered few weeks past for testing and trials.Spain With the ETR-401 Fiat delivered in 1976 a wide-gauge version to Spain that was designated Tren Basculante (RENFE Type 44 3). However like its Italian blood relation it remained a single vehicle. Later Spain developed a tilting version of its own Talgo train (talgo pendular) that so far has proved itself the only successful example of natural tilting and has met with a huge success. USA/Canada The first experiments were carried over in the thirties with non-powered cars (called pendulum), but the first successful tilting train in the USA was the Sikorsky Turbo Train which incorporate an inertial tilting mechanism.Later, in 1973 Amtrak tested an active tilting train called LRC (Light Rapid encourageable) made of ten cars, that unfortunately had no success. Today Amtrak is trying again with the American Flyer built by Bombardier using some TGV-derived technologies. Sweden ABB developed in the early seventies an active tilting mechanism that was alternative to the Italian and British ones. This was tested in the X15 vehicle and implemented in the X2000 series train that so far has had a good success. One curious feature of this trains is that the tilting mechanism is applied only to the passengers cars and not to the driving motor units.Switzerland As a part of the IC-2000 project the Swiss railways are developing a tilting train that has the provisional designation ICN-2000 and will be built by SIG. Germany Germany has adopted tilting technology on its 610 and 611 class series EMU and will built the ICT for long-range intercity services ADVANTAGES 1. Fuel consumed by the trains can be minimized. 2. Speed of the trains can be maintained constant and hence time to reach the destination is minimized 3. Their will be Comfort ness for the passengers. DISADVANTAGES 1. Very costly to manufacture these kind of trains. . If the coaches do not tilt then it is dangerous. heavyset While the Very high speed trains like the TGV could be regarded as the Rolls Royce of trains, tilting trains could be thought of as the cheep and cheerful mini metro. The price differential is fairly similar to o, it costs about 20 times more per unit distance to build a dedicated high speed line than it does to upgrade existing lines for tilting trains. This is what makes tilting trains extremely attractive. However there are disadvantages. 140mph or 230km/h is about as fast as trains go when not on dedicated lines.And then they have to be fitted in with slower moving traffic. With rail travel growing all over Europe, the problems of railways reaching saturation point has forced new lines to be build. This is why despite the success of the Italian Pendolini a new high speed line with 300 km/h trains is being built, because existing lines are at saturation. BIBILOGRAPHY conjecture of machines KHURMI . R. S Railway Engineering PROFILLDIS . V. A www. goggle search. com TILTING TRAINS pic TILTING OF TRAINS WHILE TAKING RIGHT TURN IN THE TRACKS pic TILTING OF TRAINS WHILE TAKING RIGHT TURN IN THE TRACKS

The Pazzi Conspiracy Essay Example for Free

The Pazzi Conspiracy Essay pluck On a sunny Sunday in April of 1478, assassins from the Pazzi family attacked Lorenzo de Medici and his br some other Giuliano. Giuliano lay bleeding on the duomo floor, and later bled to death. Lorenzo, however managed to get to safety non a well thing for the Pazzi family. Up to this destine the Pazzi kindred had been con steadred one of the most noble and well-respected clans. They were financiers who feared and resented the Medicis swaggering new role as political bosses. 4 This failed blackwash enterprise doomed the Pazzi family. The Medicis pull forth swift and brutal r eventidege. sever bothy of the Pazzi family who had taken part in the black lotion attempt was either hanged or be linteled, and the bodies were hung from the windows of the g e trulywherenmental palace. As if this wasnt punishment enough, the Pazzis were forced to change their surname. E very(prenominal) remnant of evidence that the Pazzi family had once been a well- respected clan was wiped divulge by the Medicis. 4It was east wind Sunday within the Cathedral of Santa Maria del Fiore. The Priest was well(p) bringing the Mass to a close, when assassins attacked the deMedici brothers, Lorenzo and Giuliano, brutally stabbing them. Giuliano was stabbed a horrifying ninerteen whiles, and the blood drained from his body right there on the cathedral floor.Lorenzo, however, was stabbed only once in the neck, a put d aver that apparently missed any major arteries, and he fought his attackers with all his might until he got free and ran away(predicate) to hide. 5 Of course there was chaos within the cathedral, and some brave instinct ran to pull the bell pull to send out a distress call and summon other Florentines to help contendd off the coup attack taking place within the cathedral walls. shortly thereafter every church in Florence was also tolling their bells, call the men of Florence to defend their Re usual.Who were these Medicis who had t aken control of their government? It is believed that they were descendants of apothecariestodays pharmacistsand were relatively unknown in the 14th century. Giovanni Medici was the wizardry of the family and his line of products acumen and sheer boldness brought the Medici family from the shadows directly to the forefront of the political world in Florence. 6 Giovanni was one of five tidingss. He lived with their mother, a poor widow woman. A wealthy cousin of Giovannis acquired a position for Giovanni as an employee of the Medici Bank in Rome, and it was not keen-sighted before Giovanni, demonstrating his boldness and business prowess, moved straight to the top in the bank, rattling displacing his own cousin.Giovanni was a blatant risk taker, and began launder money for Baldasarre Cossa, commonly known as a pirate. Giovanni even went so far as to put up the money to allow Cossas bid for the Papacy, and in 1410 Cossa was actually elected pope earth-closet XXIII. Of course th e former pirate felt obliged to final payment his good friend Giovanni by making the Medici family the new Papal Bankers. Giovanni became known as Gods Banker.This turned out to be kind of a lucrative venture for both parties involvedthe former pirate, and the former nobody who rose to such a high position. The Medici bank received a hefty ten percent of everything the church brought in. At this time in history there was a rather unscrupulous debt collection service black market by the church itself. If people didnt pay, they were promptly excommunicated, a very powerful motivator. Soon the Medici family were the trey wealthiest family in Florence, much(prenominal) to the dismay of the older, more established families who saw the Medici family as money-grubbing interlopers.Giovanni Medici soon built an broad(a) network of thugs and thieves who both demanded and rewarded unconditional loyalty. He set up the banks so the managers shared a run a risk in their bank, and even b anned loans to Kings or Princes, as he felt they were absolutely the worst risks. He often advised his descendants to Always keep out of the public eyenever constitute pride. 6 It would hurl been better for all involved if they had taken this advice to heart.Giovannis son, Cosimo de Medici was trained from a very early age to take over the banking empire from his father. Cosimo was a dedicated learner, studying classic texts, attention lectures and becoming one of the first generation of Humanists. Cosimo urged his father to turn the familys wealth to civil patronage. 6 When Cosimo inherited the position of Capo from his father, the Albizzi family, another wealthy, powerful, family made up treason charges against him out of sheer jealously and Cosimo was actually sentenced to death for these false claims.Luckily he bribed his way from prison and hid out for a while, later reverting to Florence more powerful than ever. However, shortly after Cosimo returned, he was attacked in a d ark alleyway and his attackers cut his face from ear to ear. He lived, but bore the scars known as che brutta figura, which translates into revenge through humiliation.6 Cosimo, much like his own father well understood how politics and power worked. His own advice to his heirs, which was much like his fathers advice to him was, Do not seek power. Wait until they call you.Cosimo had two sons, Giovanni and Piero. Giovanni was sure as shooting his fathers favorite, and was obviously being groomed to take over the family business while Piero was sickly, and stayed out of the public limelight because of his ill health. Piero devoted himself to learning, and became well-respected as a diplomat. In feature, King Louis XI had such a high opinion of Piero that he gave him the specially bestowed honor of permitting Piero to stamp the lilies of France on one of the balls of the Medici fortificationthis one ball colored blue for that purpose. 6 When Pieros brother Giovanni died unexpectedly, Cosimo began grooming his grandson, Lorenzo to take over because he felt Pieros health was unstable and that he couldnt handle the job.Piero had two sons, Lorenzo and Giuliano. Lorenzo, at the tender age of seventeen was well known for his courage and boldness, single-handedly foiling a Pitti family spell to assassinate his father Piero. 6 Lorenzo was indeed well educated in banking and diplomacy in holy order to follow in the family footsteps, but he apparently also had a lust for the other side of life wine, women and song.He married at nineteen and fathered seven tiddlerren, two of them adopted. Lorenzo was a patron of the humanistic discipline and promoted such artists as Bottcelli and Leonardo DeVinci, even going so far as to take a young Michelangelo into his own home and raising him like a son. 6 Lorenzos trademark pronounce was somewhat diverse from that of his father and grandfather He who wishes to be happy let him be so, for of tomorrow there is no knowing.Giuliano de Medici was Lorenzos younger brother, and shared Lorenzos passion for life. He fathered an illegitimate child in his youth, and when he was murdered on that fateful Easter Sunday Lorenzo later adopted that son. firearm Giuliano loved his older brother, there was also some natural resentment involved in their relationship.As for the Pazzi family, consider this heritage During the First Crusade in 1088, as Christian soldiers scaled the walls of Jerusalem, a protagonist named Pazzo Pazzi was the first man over the top. Pazzo was often known as the madman. 11 As a reward for his courage, he was gifted three small stones from the Holy Sepulcher. 7 The Pazzi were an old Florentine family, and two of the family members were even named in Divine Comedy, by Dante. There were also boasts of having a knight in each generation. The Pazzi weapons which reflected their long and noble history contained crescents, battlement towers and twin dolphins on a blue field with nine crosses. 7 The i mplements of war represented Christian faith, generosity and freedom, and the Pazzis dis goldbricked it proudly.Andrea de Pazzi entered into banking in the fourteenth century. He was a sharp businessman and quickly amassed a episode. However, being one of the grande names in the area they were excluded by Florentine law from participating in their own government. Because of this law, Andrea decided to relinquish the status of grande and book his own sons the opportunity to hold public office. 7 During a visit in 1443 by pontiff Eugene IV to the Pazzi family, the pontiff made a deposit of 4000 florin into the Pazzi bank, showing that there were Papal accounts that could be pried away from Medici control.Andrea left three sons, Antonio, Piero and Jacopo, all of whom were well-educated in the banking trade and all of whom held a large fortune and extensive assets. Jacopo was the only son who would live long enough to become enmeshed in the confederation to assassinate the Medici b rothers. 7 Interestingly, however, Jacopo happened to also be a strong supporter of Piero de Medici, Lorenzos father. Jacopo was known passim for his great generosity to the poor, and although he began as an observer, he eventually allowed his nephew, Francesco, son of Antonio, to draw him into the blackwash plot.Francesco, Jacopos nephew was known as diminutive, pale and driven, but apparently he harbored great resentment for the Medicis, in fact it soon became apparent to all that his nuisance of the Medicis had overtaken every aspect of his life, and even allowed him to conveniently freeze that he was in fact related to the Medici through jointure. 7 This urgency that Francesco displayed, along with his discriminating hatred for the Medici clan became the driving force for the assassination plot.So, now we know close the Medici clan and the Pazzi clan. The other factor out in this triangle were the Pope and his court. The confederacy planned by the Pazzi actually had the blessing of the church because Pope Sisto IV contemplated to demolish the dominion of Medici and for this purpose he sustained the groups led by Pazzis family which had replaced de Medici in the office of bankers.Francisco della Rovere was destined from his very childhood for the Franciscan order. 8 On the death of Pope capital of Minnesota II, he was elected pope and called Pope Sixtus IV. Unfortunately Pope Sixtus used his position as Pope to further his own family members by obtaining political appointments for them. When Lorenzo refused Sixtus demand on the Medici bank for a loan of 40,000 ducats to leverage the town of Imola, the conspiracy was set into motion. 8 Sixtus treasured to acquire the town in order to give it to his nephew, Riario.Girolamo Riario was the nephew of Sixtus and was one of the key plotters in the assassination attempt on the Medici brothers. Riario married the daughter of the Duke of Milan, and used this marriage to attempt to sabotage the relationship between the Duke and Lorenzo. Riario fueled Francesco de Pazzis inner fire by intimating that the Pazzi family would play a large part in the next government of Florence, while coveting the future Dukedom of Florence for himself.Archbishop Francesco Salviati was innate(p) into one of Florences most active political families and was related by marriage to the Pazzi, Medici, Vettori, and other very powerful families. 8 Salviati was a flatterer, a gambler, and lusted for the power that could be attained through church favour. 8 He easily became a co-conspirator in the attempted assassinations.Count Riario himself summoned Battista to meet with himself and the Archbishop Salviati. Salviati strongly persuaded the others to agree with him about wanting a coup d tat in Florence, and Riario and Salviati then outlined what they considered to be Lorenzos evil intentions against each of them, telling Battista repeatedly that when the Pope died, Riario and his state would be in grave danger fr om Lorenzo. 10 Riario and Salviati finally bluntly told Battista that the only thing to do was to cut Lorenzo and Giuliano to pieces, to exhaust military realise in secret, and to go into Florence and do this thing. 10. Battista was reluctant, believing they were discussing something very big, and he wasnt sure he wanted to become involved, but the other two were persuasive.Although nobody knew at the time, there were literally hundreds of mercenary troops settled firmly within the borders of Tuscany, poised to invade the city at a signal that never came. It was Salviati and Francesco de Pazzi who masterminded the plot to assassinate Lorenzo and Giuliano. Riario, always working behind the scenes, remained in Rome. Interestingly enough, the plan was hardly a secret, and was fairly widely known. The Pope reportedly even stated that I support itas long as no one is killed. 11 Rather a silly statement when the plot is an assassination plot.When Lorenzo escaped the assassination attem pt, he locked himself in the sacristy. A coordinated attempt to capture the Gonfaloniere and Signoria was thwarted when the archbishop and the head of the Salviati clan were trapped in a room whose doors had a hidden latch. 11 The assassination attempt had failed, and enraged Florentines seized and killed the conspirators. 11 Jacopo Pazzi was tossed from a window, and if that werent enough to kill him, he was finished off by the angry mob, then dragged naked through the streets and eventually thrown in the river.11 The entire Pazzi family were barren of all their worldly possessions, and every vestige of their name effaced. 11. Salviati, even though he was an archbishop was summarily hanged on the walls of the Pallazo. Lorenzo actually appealed to the crowd to show mercy, but to no avail, as many of the conspirators and even those only incriminate of being co-conspirators were killed. Lorenzo managed to save the nephew of Sixtus and two other relatives of the plotters, and the mai n conspirators were hunted down throughout Italy.During the assassination plot, Marsilio Ficino, who was the son of Cosimo Medicis physician, became important in his own right. In 1478, largely as a result of the war which resulted from the assassination plot, the plague broke out in the city of Florence. Ficino published a very different sort of work a practical guide to the treatment of the plague, and was written in Tuscan to be readily accessible to his fellow citizens. 12 This work went on to be translated into Latin and published aboard Galens work on fevers, as a standard medical work. It is easy to forget that all Ficinos works of profound contemplation and leisurely presentation were written against a backdrop of intense social and political disturbances.Another player in this era was Caterina Storza, an illegitimate daughter of Galeazzo Maria Sforza who stop up married, at the age of fourteen, to Girolamo Riario, the nephew of Sixtus, and a primary player in the assassin ation attempt on the Medici family. Caterina came to be known as the Machiavellian mother in Machiavellis works. 1 Eventually, after the assassination attempt, the tables were turned and Riario was murdered by a group of conspirators in his own home, just after lunch. The bloody group then took Caterina, her mother, her two half sisters, an illegitimate son of Girolamos and her six children, captive.Although the aim of the assassination attempt was to get rid of the Medici family, and show Lorenzo in a bad light, the consequence of the fateful Easter Sunday actually showed quite the opposite. Lorenzo had kept his head during the entire chaotic episode, and he would show time and time again as things progressed that he was intelligent and calm in the very worst of circumstances. When the conspiracy fell apart, Sixtus was furious and drew up an ecclesiastical censure against Florence, withdrawing sacraments and the right to a Christian burial from all the citizens of Florence.He ex communicated Lorenzo all on his own, which actually had little effect, so he formed a military alliance with King Ferrantes of Naples and began planning an attack on Florence itself. 3 The allies that had previously helped the Medici were not anxious to help the Medici fight the Pope, and even though it seemed there would be another disaster, Lorenzos magnificent tact, averted it. Switching effortlessly from avenger to peace-maker, he personally traveled to Naples to confer with the King, and an understanding was achieved without resorting to war. From then on Lorenzo became known as the Savior of Florence.Lorenzo followed closely the policy which was begun by his grandfather Cosimo. He managed to maintain a balance of power between the five chief Northern Italian states, forming defensive alliances and thus property a check on invasions from foreign powers. 3 The Medici Bank had been somewhat neglected since Cosimos time, as he had turned more and more to politics, and though Lore nzo did his best to turn this around, he found himself, for possibly the first time in his life, in financial difficulties. To keep himself afloat, he resorted to embezzling Public Funds, and it was this that later undermined his rule.Although we have all been led to believe that history belongs to the victors, it is still very sad to understand that every make of the Pazzi family, one of Florences oldest and most respected families, was wiped out following the attempted coup. 13 The Pazzi coat of arms was torn off their buildings. A special governmental commission spent the next two historic period disentangling Pazzi assets with a view to confiscation. Anyone with the name of Pazzi was forced to change it. Women of the family were forbidden to marry in Florence, which was as good as not allowing them to wed at all. No portrait of any Pazzi adult is known to have survived.It is an entire piece of history completely destroyed as a result of one act. The aftermath of the Pazzi Con spiracy continued for many, many years after the event itself. As stated, Lorenzo became something of a hero, despite his misappropriation problems, and when he died at the young age of forty three, there was a massive display of public grief and the entire population attended his funeral. He was buried in the Medici Chapel in the Church of San Lorenzo, where his brother Giuliano already rested. 3 Lorenzo left behind quite a legacy however his fleck son Giovanni and his nephew Giulio (the illegitimate son of Giuliano, who had been captured with Caterina after Giulianos death) were later to become very powerful popes, Pope Leo X and Pope Clement VII. 3Works Cited1. Hairston, Julia L. Skirting the Issue Machiavellis Caterina Sforza. reincarnationQuarterly, Volume53, Issue 3, (2000)http//www.questia.com/PM.qst? carry out=printdocId=5001097598 (October 17, 2006)2. History of Florence. The Pazzis Conspiracy. (2004).http//www.aboutflorence.com/pazzi-conspiracy.html. (October 13, 2006).3. Lorenzo. Lorenzo the Magnificent. 2005.http//www.buzzle.com/editorials/4-19-2004-53113.asp (October 16, 2006).4. Martinez, Lauro. April Bood Florence and the Plot against the Medici. OxfordUniversity Press, USA (April 1, 2003).5. McClelland, Aaron D. The Pazzi Conspiracy (2005).http//www.3.telus.net/Quattrocento_Florence/pazzi.html (October 15, 2006).6. McClelland, Aaron D. The Medici. (2005).http//www.3.telus.net/Quattrocento_Florence/pazziplayers-medici.html(October 15, 2006).7. McClelland, Aaron D. The Players, The Pazzi. (2005).http//www.3.telus.net/Quattrocento_Florence/pazziplayers-pazzi.html(October 15, 2006).8. McClelland, Aaron D. The Pope and His Court. (2005).http//www3.telus.net/Quattrocento_Florence/pazziplayers-pope.html.(October 15, 2006)9. McClelland, Aaron D. The Conspiracy. (2005).http//www3.telus.net/Auattrocento_Florence/pazzi-conspiracy.html(October 15, 2006).10. McClelland, Aaron D. The Second Meeting. (2005).http//www3.telus.net/Quattrocento_Florence/pazzi-se cond.html(October 15, 2006).11. Pazzi. Pazzi Conspiracy. (2005). http//www.answers.com/ issuing/pazzi(October 17, 2006).12. Rees, Valerie. Marsilio Ficino Renaissance Man. History Today, Volume 49, Issue7, July, 1999. http//www.questia.com/PM.qst?action=printdocId=5001275749(October 13, 2006).13. Walters, Colin. A Florentine Family Tires of Medici Rule. The Washington Times,May 18, 2003. http//www.questia.com/PM.gst?action=printdocId=5001929719(October 14, 2006).

Adventures Of Tom Sawyer Essay Example for Free

Adventures Of tomcat sawyer EssayI volition never for get along the time I spent with turkey cock sawyer, huck Finn and Joe Harper on Jacksons Island. We father always wanted to become pirates. Now that we puddle found the exact opportunity gobbler being scolded by Aunt Polly and Joe Harper having been whipped by his perplex for tasting sour cream we directstrong that it is now time to pursue our dream to become factual pirates. In that way, we will be able to conk a carriage of freedom and fame, and the whole t knowledgeships populate will hear about our names. The people who mistreated us will also feel misfortunate for what they had d mavin.Our rendezvous is Jacksons Island, which is three miles below the town of St. Petersburg. We met there at midnight. That became the become of our lives as pirates of the sea. Personally, I loved the idea of running away from home. I never had to go to shoal whatevermore. I didnt need to follow rules anymore. And as go bbler promised often, all we will need to do is to steal, pop up and get rich. So when midnight came, the four of us met at Jacksons Island. Each of us came with just aboutthing stolen. Tom brought stolen ham, Joe had a one sided bacon and huckaback had a skillet and some tobacco leaves.I brought stolen matches from my moms drawer. I figured that if we would stay long in the Island, we would need fire for our daily needs. Tom applauded me for carry some matches. In those days, matches atomic number 18 not commonly apply in St. Petersburg. Very few people had them. We found a raft about a hundred yards away. So we decided to dumbfound some fun with it and as usual, Tom was the captain. He commanded our pirate ship as we all pretended to be real pirates, using terms we have heard from sailors as well as lines from books we have read.We decided to settle in a virgin forest about two hundred yards above the head of the island. There, we spread our belongings and also built a huge bonfire. We cooked our ham, bacon and corn pone by roast them in the fire. We ate and ate until we were so full. There was nothing like it. If the an new(prenominal)(prenominal) boys in the hamlet saw us that way, they would greatly envy us without a doubt. There was nothing like a pirates life. After eating, we lay down on the grass and talked for a while. Tom started to tell apart us stories about pirates how extravagant they are, and how rich and famous.We started to ask him many questions about becoming a pirate. He simply told us that all we had to do was steal belongings and kill other people. In the thick of the conversation, Huck Finn began to smoke tobacco I instantly followed him with that activity and smoked tobacco as well. Tom and Joe simply looked silently at us in amazement. For a long time now, they had wanted to come across how to smoke, still never had the opportunity. Only Huck and I could smoke. After much talking, we all fell slumbrous one by one. That w as our first night as pirates. Tom was the first to wake up in the morning.The first thing we did was to strip ourselves off our clothes and bathe in the sea. After that, we got ready for breakfast. Joe began to cutting bacon and would have cooked it, but Tom and Huck asked him to wait. I was the one who caught a couple of sun roost and catfish We instantly cooked those fishes along with the bacon and they tasted so good. Then after eating, we lay down on the spine for a long time. Sadness started to creep in, but nada dared to speak about it. Nobody wants to be accused of being a chicken heart. I think Tom was starting to feel wishful in like manner, but he didnt want to show his feelings.Our growing homesickness was interrupted when we saw a ferry boat afar off, shooting cannon over the water. This is a sign that somebody in the settlement got drowned. Shooting cannons over the water made drowned people come up to the top. For a while we wondered who got drowned, and cons equently Tom suddenly had a brilliant impression. We are the ones who got drowned The entire village was searching for us. Our parents missed us, and the other boys surely heard about us. The girls we respect are now talking about us too We spent the rest of the entire day swimming, talking, eating and exploring the island.When night came, e preciseone went to sleep. When I woke up in the morning, Joe and Huck were still sleeping. Tom, however, was nowhere to be found. I looked at the spot where he slept and found a note. I opened the note and it read like this If I dont come back by breakfast time, all my things are yours.. Upon reading this, I woke Joe and Huck and showed them the note. We waited for Tom for about an hour but he never came. Huck supposed that Tom felt homesick and went back to Aunt Pollys house. However, Joe defended Tom and said that he knew his friend would never do such a disgrace.Tom, according to Joe, knew the rule of pirates and he is too proud to quit a nd go home just like that. I told Joe to start cooking breakfast and if Tom never returned by the time we ate breakfast, all his things will be ours. But just before we started to eat, Tom appeared dramatically and entered the camp. He had some news for us. He had spied on St. Petersburg and discovered that the whole town was talking about us the lost pirates. If our bodies were not found until Saturday, our funeral will be pronounced that very Sunday. We instantly felt like heroes.Then suddenly I had a brilliant idea. What if we could make a comeback on the day of our funeral? Tom and the other pirates liked it very much. Tom slept until noon and when afternoon came, we started to plan our appearance at our funeral on Sunday. That Sunday, while the entire town mourned for us and as the minister preached his eulogy for the dead boys, we were hiding in an unused gallery privy the church as we listened to everything that was happening. Suddenly, we made our appearance to the crowd. Needless to say, everybody welcomed us dramatically. Our loved ones cried with joy.We were the talk of the town for some(prenominal) months and I will never ever forget it. It was the best day of our lives. Part 2 The exposition The pirate boys led by Tom Sawyer built a community that they have merely created amongst themselves. It is a community apart from the regular life they have known at St. Petersburg. We can safely say that Tom, Joe and Huck built their pirate community based on their childhood imagination. As teenaged people in a simple town, where modern industrialized America has not yet to the full penetrated, these three boys have an inclination towards idealism.Their idea of a stainless life is total freedom. Thus, they chose to pretend as pirates and imitate the pirates code of conduct in order to experience the life that they have always dreamed about. To them, escaping to Jacksons Island is more of an omit from universe. Although they have romantic idealisms as pirates in a free world, the reality remains that in the town of St. Petersburg, they are children and they are not as powerful as they suppose themselves to be. Tom Sawyer is just a kid who can get whipped by Aunt Polly any time of day. He is a student who needs to go to school and study his lessons.He is part of society. So as we have stated, going to Jacksons Island is an escape from reality. The boys thought that they can build a community on their own apart from society, authority and responsibility. This thought is evident in Toms opening thoughts in Chapter 13 Toms principal was made up now. He was gloomy and desperate. He was a forsaken, friendless boy, he said nobody loved him when they found out what they had driven him to, perhaps they would be sorryYes, they had forced him to it at destination he would lead a life of crime. There was no choice. (Twain, 1876). In the community that the boys built, each one played an important role. Tom was the leader because he was the one who provided the vision and insight about the life of a pirate. So in essence, he was providing direction for all of them. Almost everything they did during their getaway in the island was a product of Tom Sawyers imagination based on what he read from books and his own thoughts and romantic dreams. Joe Harper, meanwhile was more of a follower. He also executes Toms orders. It is evident that Joe admired Tom for everything that he was.Joe once said No, Toms true-blue, Huck, and hell come back. He wont desert. He knows that would be a disgrace to a pirate, and Toms too proud for that sort of thing. Hes up to something or other. Now I wonder what? (Twain, 1876) Huck, meanwhile, is a symbol of the free life that Tom and Joe have always longed for. Huck didnt need to go to school. He is a waif, a vagabond and he is not part of society. The other boys envied Huck because he can smoke tobacco while most boys in St. Petersburg even Tom and Joe cannot do that act.Although Tom wa s the leader, we can say that Huck is the role model for the entire community they have built for themselves. If, for Tom and Joe, the island getaway was an escape from reality, it was a normal day for Huck. He was probably used to going to different places all by himself. The simple community of Huck Finn, Joe Harper and Tom Sawyer was similar to adult communities in that they have a single driving force the desire to live a life of freedom. If we look at history, almost all communities started with that single driving force.In any given community, there should be a leader, a follower and a symbol of inspiration. As these traits are respectively found in each of our characters, we may say that Tom, Huck and Joe are a perfect embodiment of American idealism. Although their deeds were shown in boyish manner, they represent a greater dimension which reflects the reality of adult life. As the saying goes, Men are simply boys who grew up. Works Cited Twain, Mark (1993). The Adventures Of Tom Sawyer electronic version. New York Project Gutenberg Ebooks. (Original work published 1876)

Radio Frequency Identification (RFID) System

intercommunicate Frequency Identification (RFID) SystemLiterature review2.1 RFIDThe Radio Frequency Identification (RFID) frame is a technology for automated assignment. Exploration of RFID technology dates back to 1948 when Harry Stockman published his research highborn Communication by means of the reflected authority. Unfortunately technologies such asintegrated circuits, transistors and microprocessors were not yet useable and RFID had to wait another20 years for its first commercial application (Landt 2005). Between 1970 and 1980 several researchlaboratories and academic institutions carried out work on RFID implementations for animal tracking,theft prevention, item labelling and access control dusts (Want 2006). disregardless of theseapplications, RFID governing bodys remained obscure for m both years. The first signifi buttockst change to thisoccurred in the early nineties when companies across the being began to use RFID tags on a large scaledue advancements in their energy efficiency and coat reductions (Landt 2005).Todays systems atomic spell 18 usually composed of either passive or restless RFID tags and RFID readers.Active tags contain their ingest power source and thereby stop transmit stronger signals and goat beaccessed from further distances. Most commonly they work on the ultra-high frequency (UHF) bandand can achieve up to 100 metres wheel depending on the surrounding environment (Weinstein 2005).There are currently two types of active tags. Transponders, also called semi-active tags, and Beacons.Transponders stay in standby mode until receiving signal from the reader and then transmit a signalback. Beacons emit signals and drive their presence at pre-set intervals. Because of their on boardpower source, active tags are expensive, priced from $20 to $70 and set out in size from 2 centimetresupwards (Williams et al. 2014). Passive tags do not incorporate a power supply and are powered by theelectromagnetic signal received fr om the reader through the tags antenna. They operate on low, highand ultra-high frequency with signals ranging up to 10 metres depending on the tags backscatter power(Weinstein 2005). The smallest passive tags can be size of a grain of rice and cost 1/10 of the price ofthe active tag (Williams et al. 2014).Silva, Filipe and Pereira (2008) proposes a RFID tack student attending recording systemthat comprises of RFID readers operating at the cxxv Kilohertz (KHz) frequency with an effective readrange up to 10 15 centimetres and passive RFID tags engraft into plastic cards. The tags store abinary identifier which is unique to from each atomic number 53 student. Readers are connected to the local profit with RJ45connector through which they transfer scanned tag id to the server using the Transmission ControlProtocol / profits Protocol (TCP/IP). At least one reader is mounted in each of the classrooms andstudents need to seduce their card out and place it near the reader in orde r to register their attending.Nainan, Parekh and Shah (2013) claimed that a mistakable RFID attendance allowance system setupdecreased the time needed to record a students attendance by 98% compared to the manual entrymethod. Collected data shows that the RFID system was able to record the attendance of 5 students persecond, however considering the short effective read range we have to conclude that multiple readerswere utilise during that experiment to achieve such result. Despite advances over the paper basedregisters, efficiency of attendance systems based on passive RFID tags is limited by the number ofreaders located in the classroom. Analogous systems based on the active RFID technology couldincrease ids collection efficiency by scanning multiple tags simultaneously from a further distance(Yoon, Chung and Less 2008), however such systems would introduce a number of additional technological and social issues. Bandwidth limitations coerce RFID tags to portion a common broa dcastfrequency and as a resultant multiple tags responding concurrently to the same reader can causepacket collisions. Therefore to solve these issues, locomote anti-collision algorithms and methods must(prenominal)be employed during development process (Bin, Kobayashi and Shimizu 2005). Increased reading range additionally raises unspoilt privacy concerns as the users location could be tracked without their ownconsent (Ferguson, Thornley and Gibb, 2014).2.2 BiometricsNumerous properties must be satisfied to categorise the biological measurement of a humanphysiological or behavioral characteristic as biometrics. The characteristics should be unique, everyperson should have it and it needs to be accessible so it can be measured. There are a number of differentstudies exploring biometric authentication for attendance registration systems.2.2.1 Voice acknowledgmentRecent experiments by Dey et al. (2014) explore the capabilities of an attendance registrationsystem based on voice recognition. The main core of the system is a Linux OS server integrated with a estimator telephony interface (CTI) card and pre-installed with interactive voice response (IVR)software. The server is accessible only from the previously pre-defined phones which are installed inthe classrooms. Using installed phones users have to record a reference voice test to write in code into thesystem. During enrolment users are provided with a unique four digit speaker identification then theyare asked to read for 3 minutes text of their own choice. Enrolled users can register their attendance by debut the previously received speaker identification number and then answering some simple hit-or-missquestions start outd by the system. The system logs user attendance if the recorded speech matches thestored reference sample. Initial system military rating performed on the group of 120 students indicatedvery low efficiency. In order to achieve 94.2% recognition rate, each user needs to produce at least a 50seconds sample. Authentication time is additionally extended by an average 26 seconds computationaltime needed to give way provided speech sample. extra limitations come with the maximum numberof 32 concurrent calls that each server can handle. In essence, a long compulsory enrolment process,the unnecessary burden of remembering a personal speaker identification number and the poorregistration efficiency time make the system a poor expectation for large group registers.2.2.2 FingerprintsAccording to Akinduyite et al. (2013) fingerprint attendance management systems can be more accepted and efficient than the voice based equivalent. They have achieved 97.4% recognition accuracywith an average registration time of 4.29 seconds per student. The system implements fingerprintscanners connected to a centralised server through the be Wi-Fi infrastructure. As with the voicerecognition system, an administrator has to capture reference fingerprint data from every user befor ethe system can be employ. Collected fingerprint scouts are stored on the server in a Microsoft SQLServer database and subsequently used to match scanned samples. Almost identical recognition rate of 98.57%was achieved by Talaviya, Ramteke and Shete (2013) in the similar fingerprint system setup. Analogousto the RFID based systems, the efficiency is closely related to the total number of the available scanners.2.2.3 automatize Face recognitionAll of the prior systems require users to provide a biometric sample manually by using one ofthe available scanners located in the environment. Kawaguchi et al. (2005) proposed a considerablydifferent solution which automates sample collection. They introduced a face recognition method basedon continuous observation. The system requires two tv cameras drift live data to the centralized unitwith preinstalled face detection and recognition software. The first camera, called the spotting camerais installed on the ceiling and points towards t he rooms sitting area. The second camera, called thecapturing camera is located in front of the pose to capture students faces. The sensing camera scansover the room in order to detect seats in use(p) by the students. Received image data is analysed usingthe Active Student Detecting (ASD) method create by Nishiguchi et al. (2003). Once a student isdetected, the system directs the capturing camera to the found location. The face image quiet fromthe capturing camera is then processed by the system and the students attendance is recorded if amatching template is found. Experiments in which the described system was evaluated on a group of12 students revealed 80% accuracy in engaged seats detection and the same level during face detection.The whole experiment took 79 minutes in which 8 scanning cycles were performed, resulting in 70%total accuracy for the attendance registering. Despite advances in automated biometric samplescollection, the described system seems to be inefficient, e specially if we consider time required tocollect and analyse samples on such small group of students. Additional issues may arise if there areevery obstructions in the room which can restrict the cameras view or if a low ceiling prevents sensingcamera from covering the entire seating area.2.2.4 SummaryThe biometric systems have many advantages over the other authentication technologies. Thebiometric characteristics are tightly linked to the owner and can prevent identity theft, are difficult to double up and are very convenient as they are always available. Despite all these advances, all thebiometric systems share serious ethical, social and security implications. It was evidenced by manyresearchers that there is a fear of biometric technologies on the whole. The individuals and potentialsystem users are concerned about privacy, autonomy, bodily integrity, dignity, equity and personalliberty (Mordini and Tzovaras 2012 Kumar and Zhang 2010). The system administrators haveadditional overhead with the security of the collected biometric data. The individual biometriccharacteristic cannot be replaced if they get stolen, thereof the legal responsibilities whilst storing thiskind of data are colossal.2.3 Wi-FiAn interesting and novel attendance registration method was proposed by Choi, Park and Yi(2015). The authors created a system which incorporates Wi-Fi technology built into smartphonedevices. They had developed two chance variables of a smartphone application, one for the lecturers and onefor the students. When a class session starts the lecturer has to create a Wi-Fi Access Point (AP) usinghis version of the application. The students attend the lecture and scan for the available Wi-Fi AccessPoints and if the lecturers AP is discovered and students device stays in its range for specified amountof time then attendance registration process is triggered. To overcome limitations with the maximumnumber of concurrent connections that single AP can handle, the cre ated students version scans onlyfor the nearby networks but never connects to the found APs. attending is registered by submitting aMessage Digests 5 (MD5) hash token that combines a Service Set Identifier (SSID) of the found APand students smartphone Media Access Control (MAC) address. The hash token is uploaded to theserver which verifies submitted data and registers the students attendance in the local store. The systemarchitecture requires collection of the reference MAC address of all the students for the purpose of thelater validation. The study does not describe what smartphone models were used throughout theexperiment, but it seems that they did not consider privacy features on iOS devices. According to apple(2013), since the release of iOS 7.0, the MAC identifier is no longer accessible through third partyapplications, moreover subsequently iOS 8.0 release, real device MAC address is hidden from the access pointsand swapped with a randomly generated one (Apple 2015 A). p ickings into account that over 98% ofiOS devices run on iOS 7.0 and above (Apple 2015 B), only confirms that the proposed system designshould be reviewed again.2.4 Other2.4.1 QR Code with face recognitionFadi and Nael (2014) combined biometrics with Quick Response Codes (QR). The proposedmethodology requires lecturers to generate a unique QR code and display it in the class. In order toregister their attendance, students need to download a mobile application, install it on their smartphonesand use it to scan the presented QR code. The scanned code is then submitted to the server via theexisting University Wi-Fi infrastructure. Furthermore the application performs an identity check byscanning the students seventh cranial nerve image which is later used to create matching score by analysing a referenceimage stored on the servers. Lecturer can manually validate submitted images to confirm a studentsidentity if a low matching score raises any concerns. The QR code image could be effort lessly forwardedto other students outside the classroom, therefore the system also collects a location stamp on the codesubmission. The apparent vulnerability of the system lies in the number of technologies that it dependson. Authors sour that every student will have a smartphone device with front and back facingcameras for the facial images and the QR scans and also a Global Positioning System (GPS) modulewhich will be accessible during the registration stage. Each classroom has to be also equipped with alarge screen to present codes to the students and this may not always be available.