• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.22-28
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• 2017

The performance of lithium ion batteries used in electric vehicles (EV) varies greatly depending on the battery temperature. In this paper, the finite difference method was used to evaluate the temperature change, state of charge (SOC), internal resistance, and voltage change of the battery due to heat generation in the battery. The simulation model was linked with AMESim to calculate the driving range of an EV traveling in New European Driving Cycle (NEDC) mode. As the temperature dropped below $25^{\circ}C$, the internal resistance of the battery increased, which increased the amount of heat generated and decreased the driving range of EV. At battery temperatures above $25^{\circ}C$, the driving range was also decreased due to reduced SOC that deteriorated the battery performance. The battery showed optimal performance and the driving range was maximized at $25^{\circ}C$. When battery temperatures of $-20^{\circ}C$ and $45^{\circ}C$, the driving range of EV decreased by 33% and 1.8%, respectively. Maintaining the optimum battery temperature requires heating the battery at low temperature and cooling it down at high temperature through efficient battery thermal management. Approximately 500 W of heat should be supplied to the battery when the ambient temperature is $-20^{\circ}C$, while 250 W of heat should be removed for the battery to be maintained at $25^{\circ}C$.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.849-854
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• 2007

This paper describes design and tuning of a full-range Adaptive Cruise Control (ACC) with collision avoidance. The control scheme is designed to control the vehicle so that it would feel natural to the human driver and passengers during normal safe driving situations and to avoid rear-end collision in vehicle following situations. In this study, driving situations are determined using a non-dimensional warning index and time-to-collision (TTC). A confusion matrix method based on natural driving data sets was used to tune control parameters in the proposed ACC System. An ECU-Brake Hardware-in-the-loop Simulation (HiLS) was developed and used for an evaluation of ACC System. The ECU-Brake HiLS results for alternative driving situation are compared to manual driving data measured on actual traffic way. The ACC/CA control logic implemented in an ECU was tested using the ECU-Brake HiLS in a real vehicle environment.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.454-460
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• 2009

The objective of this study is to study the selection factors and satisfaction factors for different types of driving ranges and establish a basic date for marketing strategies of driving ranges. The research target group was fixed to customers older than full twenty of 12 indoor, outdoor driving ranges located in G metropolitan city & N city, M city, S city in. 564 surveys were used as effective samples. The result was achieved using the above mentioned objectives and methods.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.12
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• pp.2197-2210
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• 2016

Recently, the trend of zero emissions has increased in automotive engineering because of environmental problems and regulations. Therefore, the development of battery electric vehicles (EVs), hybrid/plug-in hybrid electric vehicles (HEVs/PHEVs), and fuel cell electric vehicles (FCEVs) has been mainstreamed. In particular, for light-duty electric vehicles, improvement in electric motor performance is directly linked to driving range and driving performance. In this paper, using an improved design for the interior permanent magnet synchronous motor (IPMSM), the EV driving range for the light-duty EV was extended. In the electromagnetic design process, a 2D finite element method (FEM) was used. Furthermore, to consider mechanical stress, ANSYS Workbench was adopted. To conduct a vehicle simulation, the vehicle was modeled to include an electric motor model, energy storage model, and regenerative braking. From these results, using the advanced vehicle simulator (ADVISOR) based on MATLAB Simulink, a vehicle simulation was performed, and the effects of the improved design were described.

• ETRI Journal
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• v.34 no.5
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• pp.727-733
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• 2012

This paper demonstrates a new driving scheme that allows reducing the supply voltage of data drivers for low-power active matrix organic light-emitting diode (AMOLED) displays. The proposed technique drives down the data voltage range by 50%, which subsequently diminishes in the peak power consumption of data drivers at the full white pattern by 75%. Because the gate voltage of a driving thin film transistor covers the same range as a conventional driving scheme by means of a level-shifting scheme, the low-data supply scheme achieves the equivalent dynamic range of OLED currents. The average power consumption of data drivers is reduced by 60% over 24 test images, and power consumption is kept below 25%.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.9-11
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• 1995

In order to achieve a essential requirement for the driving system of electric vehicles, that is, starting pick-up ability, a wound-type induction motor with double-rotor structure is proposed. Slip Power Recovery system is adopted to improve the efficiency in the low speed range and to control speed of this system. Theoretical analysis and experimental results from 300[W] prototype motor is presented to verify the improvement of pick-up ability and high-efficiency driving characteristics through the wide speed range, especially under the low speed range.

• Transactions on Electrical and Electronic Materials
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• v.6 no.6
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• pp.276-279
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• 2005

Influences of sustain pulse-width on electrical characteristics and luminous efficiency are experimentally investigated for surface discharge of AC-PDP. A square pulse with variable duty ratio and fixed rising time of 300 ns has been used in the experiment. It is found that the memory coefficient is significantly increased at the critical pulse-width. And the wall charges and wall voltages as well as capacitances are experimentally measured by Q- V analysis method along with the voltage margin relation, in terms of the sustain pulse-width in the range of $1{\mu}s$ to $5{\mu}s$ under driving frequency of 10 kHz to 180 kHz. And the luminous efficiency is also experimentally investigated in above range of sustain pulse-width with driving frequency of 10 kHz to 180 kHz. It is noted that the luminous efficiency for 10 kHz and 180 kHz are 1.29 1m/W and 0.68 1m/W respectively, since the power consumption for 10 kHz is much less than that for 180 kHz. It has been concluded that the optimal sustain pulse-width is in the range of $2.5 {\~}4.5{\mu}s$ under driving frequency range of 10 kHz and 60 kHz, and in the range of $1.5 {\~} 2.5{\mu}s$ under driving frequency range of 120 kHz and 180 kHz based on observation of memory coefficient, and wall voltage as well as luminous efficiency.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.40-44
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• 2005

Recently PZT is used in ultra precision mechanism field. PZT itself has a small driving range although it has a high resolution. Many methods, such as inchworm, impact driving, inertial sliding method, etc., have been applied for moving range expansion. In this study, a new actuating mechanism for rotational motion with two driving PZT is proposed. The Fixed-Fixed beam support is applied for compensation of the difference in driving force between expansion and contraction of PZT. The behavior and design parameters of the proposed mechanism are analyzed for improving performance.

• International journal of advanced smart convergence
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• v.1 no.1
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• pp.38-42
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• 2012

Automobilist in South Korea in order to provide car driving information to the insurance company uses 'car driving information device'. They provide car driving information of device to insurers for their premium discount. Currently these devices are used in Korea has inconvenience that this device Installation and the process for send this information to insurance companies. In this paper, Korean smart car driving information system designed using Smart phone and local-range network as a basis the 'Certification Regulations of Driving Information Check Device' of the Korea Insurance Development Institute.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.12
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• pp.888-894
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• 2015

A new method for the simulation of the vehicle's interior road noise is proposed in the present study. The road noise model can synthesize road noise of a vehicle for varying driving speed within a range. In the proposed method, interior road noise is considered as a stochastic time-series, and is modeled by a nonstationary parametric model via two steps. First, each interior road noise signal, obtained from constant speed driving tests performed within a range of speed, is modeled as an autoregressive model whose parameters are estimated by using a standard method. Finally, the parameters obtained for different driving speeds are interpolated based on the varying driving speed to yield a time-varying autoregressive model. To model a full band road noise, audible frequency range is divided into an octave band using a wavelet filter bank, and the road noise in each octave band is modeled.