• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.3
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• pp.265-272
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• 2016

The objective of vehicle aerodynamic design is on the fuel economy, reduction of the harmful emission, minimizing the vibration and noise and the driving stability of the vehicle. Especially for a sedan, the driving stability of the vehicle is the main concern of the aerodynamic design of the vehicle indeed. In this theoretical study, an evaluation algorithm of aerodynamic driving stability of a vehicle was made to estimate the dynamic stability of a vehicle at the given driving condition on a road. For the stability evaluation of a driving vehicle, CFD simulation was conducted to have the rolling, pitching and yawing moments of a model vehicle and compared the values of the moments to the resistance moments. From the case study, it is found that a model sedan running at 100 km/h in speed on a straight level road is stable under the side wind with 45 m/s in speed. But the different results may be obtained on the buses and trucks because those vehicles have the wide side area. From the case study of the model vehicle moving on 100 km/h speed with 15 m/s side wind is evaluated using the numerical algorithm drawn from the study, the value of yawing moment is $608.6N{\cdot}m$, rolling moment $-641N{\cdot}m$ and pitching moment $3.9N{\cdot}m$. These values are smaller than each value of rotational resistance moment the model vehicle has, and therefore, the model vehicle's driving stability is guaranteed when driving 100 km/h with 15 m/s side wind.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.1
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• pp.60-67
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• 2006

To improve the vehicle fuel economy, various technologies have been studied. Meanwhile it deteriorates fuel economy that the increased driving torque for Power Steering System (PSS) due to weighted vehicle and widened tire for low speed driving and parking. So the larger driving torque for PSS is, the lower fuel economy is. Therefore, the study about the effect of the driving torque for PSS and the engine total friction must be preceded to improve the vehicle fuel economy. In this study, a PSS module separated from the vehicle is used to measure the driving torque for PSS with respect to the pressure of PSS. The result shows that the driving torque for PSS was in direct proportion to the pressure of PSS 3 (N-m) driving torque for PSS vs. 10 (bar) pressure of PSS, and 8 (N-m) vs. 40 (bar). In addition, the driving torque and pressure for PSS was measured according to the engine speed in the component test condition which was in the vehicle condition. Measuring the driving torque for PSP in the vehicle condition was established by using the VeFAS which was a fuel economy analyzer developed in our lab and installing PSS By-pass line. The effect of the driving torque for PSS on the vehicle fuel economy was analyzed with FTP-75 cold start mode.

• International Journal of Automotive Technology
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• v.7 no.7
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• pp.813-819
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• 2006

As the vehicle becomes bigger and faster, the importance of vehicle stability in an extreme driving condition caused by sudden steering, road condition or unexpected case has been emphasized. The ESP system is being utilized to improve the handling performance and the vehicle stability. In this study, we implemented various tests and proposed estimation methods for ESP characteristics in extreme driving situations. The estimation methods for ESP proposed in this paper are expected to facilitate developing the control logic and improving the performance of the ESP system.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.3
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• pp.375-379
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• 2016

A current subtraction technique with parallel operation system is proposed to remove excessive current in touch screen application. The proposed current subtraction remove the current which go into the input node of charge amplifier. The value of subtraction current is same with current when touch screen is not touched. As a result, charge amplifier output is only proportional to variation of mutual capacitor, which make dynamic rage is increased. Also, Transmitter (Tx) driving signal and subtraction driving signal are out of phase each other. Thus, noise generated in Tx is cancelled. The proposed IC is implemented in a mixed-mode 0.18-um CMOS process. Overall system is designed for touch screen panel (TSP) with 16 driving lines and 8 sensing lines. 5-V supply voltages are used in the proposed circuits. For multiple Tx driving signal, Walsh codes are used and signal frequency is 300 khz. By using proposed technique, dynamic rage is improved 36 dB.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.325-328
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• 2018

With the rapid development of autonomous driving technology, commercialization of freight cars and buses as well as passenger cars has come to the near future. As researches for commercialization of autonomous navigation are being actively carried out in various countries around the world, in accordance with the development of technology, this paper proposes a bus adopting a new concept of community driving technology based on C-V2X for more effective autonomous driving of buses do. In order to realize the cluster bus, we propose a more effective cluster bus using C-V2X, which is the core communication of the cluster driving, which is complementary to the existing V2X for inter-vehicle communication and vehicle-to-infrastructure communication.

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.2
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• pp.79-86
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• 2020

This study examines the power generation characteristics of a vehicle rooftop photovoltaic module with urban driving conditions. Actual test data with an illuminometer and a thermometer were used to analyze the power generation characteristics of the vehicle rooftop photovoltaic module. In addition, the power generation characteristics were analyzed in terms of urban driving conditions, irradiance, ambient temperature, and photovoltaic module temperature. This study also analyzes the power generation characteristics of the vehicle rooftop photovoltaic module with urban driving conditions through a wavelet transform filtering method. The power generation characteristics of the vehicle rooftop photovoltaic module with urban driving conditions depend on the change in irradiance rather than that in photovoltaic module temperature.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.2
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• pp.47-54
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• 2022

For safe driving of autonomous vehicles, road damage detection is very important to lower the potential risk. In order to ensure safety while an autonomous vehicle is driving on the road, technology that can cope with various obstacles is required. Among them, technology that recognizes static obstacles such as poor road conditions as well as dynamic obstacles that may be encountered while driving, such as crosswalks, manholes, hollows, and speed bumps, is a priority. In this paper, we propose a method to extract similarity of images and find damaged road images using OpenCV image processing and CNN algorithm. To implement this, we trained a CNN model using 280 training datasheets and 70 test datasheets out of 350 image data. As a result of training, the object recognition processing speed and recognition speed of 100 images were tested, and the average processing speed was 45.9 ms, the average recognition speed was 66.78 ms, and the average object accuracy was 92%. In the future, it is expected that the driving safety of autonomous vehicles will be improved by using technology that detects road obstacles encountered while driving.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.434-437
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• 2009

To realize the advantages of e-Paper, driving systems should be separated from panels to keep its superiority in thin, light, and flexible. For this purpose, this paper develops a panel hot-plugging driving system for R2R cholesteric LCD. Its performance is verified by implementing an e-Badge application. Satisfactory results are obtained.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.3
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• pp.1-7
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• 2008

We have theoretically investigated the asymmetry effects on 10[Gb/s] optical duobinary transmitters from the viewpoint of the driving voltage ratios by computer simulations. For driving voltage ratios(=driving voltage/switching voltage) with smaller than 100[%], the transmission performance has been greatly affected by the asymmetry of the bandwidth of LPFs than that of the Mach-Zehnder Modulator driving voltage. On the other hand, for driving voltage ratios with 100[%], the transmission performance has been degraded by the asymmetry of the driving voltage and is not sensitive to that of the bandwidth of LPFs. For the transmission performance within 1[dB] power penalty under the asymmetry condition, the driving voltage ratio with 100[%] has performed better than the low driving voltage ratios.

• Journal of Information Display
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• v.11 no.4
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• pp.154-159
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• 2010

Single-sustainer driving is an AC PDP driving scheme to reduce the circuitry by maintaining the sustain electrode at ground level. To date, however, the research on the discharge characteristics in such driving scheme is insufficient. In this study, the panel performance and discharge characteristics of the single-sustainer driving scheme were observed while varying the address electrode condition. In single-sustainer driving, the address electrode is strongly involved in the sustain discharge when the former is maintained at ground level, and the dependence of the luminous efficacy on the sustain voltage is different from that in the conventional driving scheme. The dependence of the luminous efficacy on the sustain voltage appeared similar, however, to that in the conventional driving scheme when the address electrode was floated in single-sustainer driving. In the investigation of the temporal evolution of the sustain discharge using an IICCD camera, it was found that the sustain discharge in single-sustainer driving with a floating address electrode is similar to that in the conventional driving scheme, and the strong plasma formation region was located in the vicinity of the MgO surface, which seems to be related to the lifetime of a PDP with single-sustainer driving. In the investigation of the operation characteristics, the PDP that was operated with a floated address electrode showed a narrower dynamic operation margin, but a longer lifetime was expected.