• International Journal of Automotive Technology
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• 제7권6호
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• pp.703-714
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• 2006

The growing concern surrounding rollover incidences and consequences of Sports Utility Vehicles(SUV) have prompted to investigate the sensitivity of critical vehicle parameters on rollover. In this paper, dynamic rollover simulation of Sports Utility Vehicles is carried out using a validated nonlinear vehicle model in Matlab/Simulink. A standard model is considered and critical vehicle parameters like CG height, track width and wheel base are varied within chosen specified limits to study its influence on roll behavior during a Fishhook steering maneuver. A roll stability criterion based on Two Wheel Lift Off(TWLO) phenomenon is adopted for rollover propensity prediction. Further dynamic rollover characteristics of the vehicle are correlated with Static Stability Factor(SSF), Roll Stability Factor(RSF) and Two Wheel Lift Off Velocity(TWLV). These findings will be of immense help to SUV chassis designers to determine safety limits of critical vehicle parameters and minimize rollover incidences.

• Journal of KSNVE
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• 제9권1호
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• pp.25-32
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• 1999

Ground vibrations induced from road were investigated to get the basic data that can be used to prepare countermeasures for environmental vibration problems. Vibration levels were measured simultaneously at three points in double distances from road. These data were analyzed with the type of vehicles. roads, media to understand the magnitudes and characteristics of distance attenuation of road vibrations. Vibration levels recorded on tapes were analyzed to understand the characteristics of frequency of road vibration. The range which could be influenced by the road vibration was estimated to take into account the mean of$L_{max}$ and distance attenuation of vibration level 5 m from roadside.

• Smart Structures and Systems
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• 제6권7호
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• pp.867-887
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• 2010

An energy-based variational approach is used for structural dynamic modeling of the IPMC (Ionic Polymer Metal Composites) flapping wing. Dynamic characteristics of the wing are analyzed using numerical simulations. Starting with the initial design, critical parameters which have influence on the performance of the wing are identified through parametric studies. An optimization study is performed to obtain improved flapping actuation of the IPMC wing. It is shown that the optimization algorithm leads to a flapping wing with dimensions similar to the dragonfly Aeshna Multicolor wing. An unsteady aerodynamic model based on modified strip theory is used to obtain the aerodynamic forces. It is found that the IPMC wing generates sufficient lift to support its own weight and carry a small payload. It is therefore a potential candidate for flapping wing of micro air vehicles.

• Journal of the Korean Society for Railway
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• 제6권1호
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• pp.58-65
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• 2003

Wheel/Rail geometric constraint relationships, such as effective conicity and gravitational stiffness, strongly influence the lateral dynamics of railway vehicles. In general, these geometric contact characteristics are nonlinear functions of the wheelset lateral displacement. There is a need to develop a wheel/rail geometric contact simulation program for wheels and rails with arbitrary profiles for the prediction of the dynamic behavior of railway vehicles. An algorithm to simulate any combination of wheels and rails is employed and a GUI for easy analysis is constructed. The simulation program is applied to KTX which will run on both KTX and conventional rails, two rail standards having different rail profiles. The results show that the two rail systems have different geometric contact characteristic

• Proceedings of the KSR Conference
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• 한국철도학회 2003년도 춘계학술대회 논문집
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• pp.645-650
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• 2003

Wheel/Rail geometric constraint relationships, such as effective conicity and gravitational stiffness, strongly influence the lateral dynamics of railway vehicles. In general, these geometric contact characteristics are nonlinear functions of the wheelset lateral displacement. There is a need to develop a wheel/rail contact simulation program for wheels and rails with arbitrary profiles for the prediction of the dynamic behavior of railway vehicles. An algorithm to simulate any combination of wheels and rails is employed and a GUI for easy analysis is constructed. The simulation program is applied to KTX which will run on both KTX and conventional rails, two rail standards having different rail profiles. The results show that the two rail systems have different geometric contact characteristic

• Advances in aircraft and spacecraft science
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• 제6권4호
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• pp.283-296
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• 2019

The influence of different planform parameters on the aerodynamic performance of large-scale subsonic and transonic Blended Wing Body (BWB) aircraft have gained comprehensive research in the recent years, however, it is not the case for small-size low subsonic speed Unmanned Aerial Vehicles (UAVs). The present work numerically investigates aerodynamics governing four different trailing edge geometries characterizing BWB configurations in standard flight conditions at angles of attack from $-4^{\circ}$ to $22^{\circ}$ to provide generic information that can be essential for making well-informed decisions during BWB UAV conceptual design phase. Simulation results are discussed and comparatively analyzed with useful implications for formulation of proper mission profile specific to every BWB configuration.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제22권4호
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• pp.700-707
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• 2018

Vehicles are used in daily life as convenient transport, it is important to authenticate driver because vehicles are controlled by driver. Especially, in these days, there is a discussion on introduction of Driving Under the Influence car-starting locking device installation for preventing accidents caused by Driving Under the Influence of alcohol, these car-starting locking device installation requires a lot of money and time. Suitable user authentication for solving user's inconvenience during the disabled and men of national merit to receive discount benefits is needed. In this paper, For solving these problems, we propose the efficient vehicle control and user authentication system for preventing driving under the influence and providing the disabled and men of national merit benefit based on driver authentication by using user's smartphone NFC communication and user's biometric information.

• Journal of Power System Engineering
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• 제22권6호
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• pp.51-57
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• 2018

In Korea, the Air Quality Conservation Act and the Petroleum and Petroleum Substitute Fuel Business Act stipulate certain quality standards for fuels distributed in Korea, thereby striving to reduce vehicle performance and emissions. Domestic petroleum products import and produce all the crude oil from each oil refiner so that the quality of the petroleum product is different according to the characteristics of the crude oil. As a result, vehicles have been improved by using the physical properties calculated through the physical property measurement that has tried to improve the accuracy of the measurement of the energy consumption efficiency of the automobile by using standard fuel from abroad. In this study, the same test procedure and method as the test method of domestic gasoline vehicle emission are applied using four samples of gasoline and the latest gasoline vehicle which are actually distributed, and the performance evaluation is performed. The purpose of this study is to contribute to improvement of vehicle technology and fuel quality by collecting necessary basic data and obtaining data on the effect of differences in gasoline property on vehicle emissions. The results of the test showed that the emission of gases (NMOG, CO) from gasoline vehicles was the most influenced by the sulfur content, unlike the previous studies that the vehicles emission had the greatest influence on the distillation characteristics and the specific gravity of aromatic compounds. The catalytic reaction such as the poisoning action of the three-way catalyst which is the abatement device was interfered and the emission was increased. The distillation characteristics and specific gravity of aromatic compounds were found to affect the emission of vehicles. According to the physical properties of the fuel, the emission difference was 28.0% in the urban mode and 17.6 % in the highway mode.

• Transactions of the Korean Society of Automotive Engineers
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• 제16권1호
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• pp.8-13
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• 2008

Emissions from automobiles have long been considered a prime source of pollutants involved in smog formation and ozone production. Especially VOCs are associated with serious environmental problems such as photo-chemical smog as well as human health effects. Since motor vehicles are a major source of VOCs, estimating of emission from mobile source is the most important factor to control VOCs. VOCs are emitted from various pollution like motor vehicles, mobile and stationary source that has characteristics of toxicity, cancer-causing, bio-accumulation, durability in air and diffusion can exert a bad influence upon human health and environment. However we don't have any standard or regulation about VOCs emissions. This study is summarized as VOCs emission characteristics from in-use light-duty diesel and LPG fueled vehicles. The vehicle exhaust-gas test mode is CVS cycle and nier-10 cycles that developed on EPA and National Institute of Environmental Research. TO-14 method (Toxic Organic) was chosen for VOCs analysis from EPA in USA. This study results will be useful when make a emission factor and rule making of emission standard about domestic VOCs emission for the improve to air condition.

• Journal of Hydrogen and New Energy
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• 제28권1호
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• pp.56-62
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• 2017

Although most electricity production contributes to air pollution, the vehicle organizations and environmental agency categorizes all EVs as zero-emission vehicles because they produce no direct exhaust or emissions. Currently available EVs have a shorter range per charge than most conventional vehicles have per tank of gas. EVs manufacturers typically target a range of 160 km over on a fully charged battery. The energy efficiency and driving range of EVs varies substantially based on driving conditions and driving habits. Extreme outside temperatures tend to reduce range, because more energy must be used to heat or cool the cabin. High driving speeds reduce range because of the energy required to overcome increased drag. Compared with gradual acceleration, rapid acceleration reduces range. Additional devices significant inclines also reduces range. Based on these driving modes and climate conditions, this paper discusses the performance characteristics of EVs on energy efficiency and driving range. Test vehicles were divided by low / high-speed EVs. The difference of test vehicles are on the vehicle speed and size. Low-speed EVs is a denomination for battery EVs that are legally limited to roads with posted speed limits as high as 72 km/h depending on the particular laws, usually are built to have a top speed of 60 km/h, and have a maximum loaded weight of 1,400 kg. Each vehicle test was performed according to the driving modes and test temperature ($-25^{\circ}C{\sim}35^{\circ}C$). It has a great influence on fuel efficiency amd driving distance according to test temperature conditions.