• Transactions of the Korean Society of Automotive Engineers
• /
• v.19 no.2
• /
• pp.133-141
• /
• 2011

The effect of payload on fuel consumption and emission of light duty freight truck during acceleration driving has been analyzed. Running tests were carried out with various payload conditions on chassis dynamometer. A typical driving pattern for urban cities was used. Real time emission measurement systems for gaseous and soot emission were utilized to investigate the real time dynamic of fuel use and exhaust emissions. It was observed that fuel use and pollutant emissions were increased as payload was increased. Under the same payload condition, the increased amount of acceleration driving is much higher than that of steady state driving. The results demonstrated the advantages of eco-driving, which is an environmentally friendly driving manner, could be emphasized in heavier payload condition. Inertial tractive power was introduced for considering the parameters affecting emission during acceleration driving, which are speed, acceleration and payload. Fuel use and emission in various driving conditions were expressed as functions of inertial tractive power. The estimated result by these functions well predicted measured result within 10 % deviation.

• The Journal of the Convergence on Culture Technology
• /
• v.7 no.4
• /
• pp.641-652
• /
• 2021

Drivers have willing to do secondary tasks in situations deemed safe autonomous driving. I studied that positive notifications for secure areas could improve situation awareness and driving performance after TOR(Take over request) in autonomous driving. Comparing TOR alert only and monitoring alert conditions, participants in the positive notification condition showed higher situation awareness and driving performance. Also, in emotional assessment, the positive notification condition showed higher positive evaluation than other conditions. Due to Covid-19, I designed experiments separate online with driving videos in experiment 1 and offline using a driving simulator in experiment 2. This study has implications that presented a different perspective on autonomous driving notification design.

• Korean Journal of Culture and Social Issue
• /
• v.12 no.3
• /
• pp.69-83
• /
• 2006

The purpose of the present driving simulation study was to investigate the effects of fatigue induced both by sleep deprivation and time-on-task on driver's driving performance. The results are as followings. First, although the drivers in almost every experimental conditions showed faster driving speed than that was required, the drivers in the sleep-deprivation and over 1-hour time-on-task condition drove slower than the target speed. Second, the drivers in the sleep-deprivation and over 1-hour time-on-task condition crossed the lane less frequently than those in the other conditions, they weaved more in the lane. Third, as the drivers became more fatigued both by sleep deprivation and continuous driving, they reported higher fatigue scores in the subjective fatigue ratings. The results suggested that although the drivers might adapt a compensative driving strategies when they were fatigued, their driving performances were indeed impaired, in general.

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

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.9 no.6
• /
• pp.127-132
• /
• 2000

Morphological analysis of wear particles is one of useful methods for machine condition monitoring because it is well reflected in machine driving state. This paper was undertaken to apply to the condition monitoring of hydraulic piston motor. The lubricating wear test was performed under different experimental conditions using the wear test device and wear specimens of the pin on disk type was rubbed in paraffinic base oil by three kinds of lubricating materials, varying applied load, sliding distance. The four shape parameters(50% volumetric diameter, aspect, roundness and reflectivity) are used for morphological analysis of wear particles. The results showed that the four shape parameters of wear particles depend on a kind of the lubricating materials. It was capable of calculating presumed wear volume for three kinds of materials on driving time to foresee as damage condition of lubricating materials.

• Science of Emotion and Sensibility
• /
• v.4 no.1
• /
• pp.23-31
• /
• 2001

Psychological and physiological effects from simulator sickness could be an important bias factor for sensibility evaluation. The present experiment investigated the effects of simulator sickness on sensibility evaluation in the controlled condition of driving a car for 60 minutes on a constant speed (60km/h) in graphic simulator. The simulator sickness was measured and analysed for every five minutes using their subjective evaluation and physiological signals. Results of the subjective evaluation showed that there was significant difference between rest and driving condition at 10 minutes from the start of driving, and the level of difference was increased linearly with time. The analysis on central and autonomic nervous systems showed the significant difference between rest and driving conditions after 5 minutes from the start of the driving on the parameters $\alpha$/total and $\beta$/total, and increased level of sympathetic nervous system. But there was no significant difference between different time conditions. The results indicates that physiological changes from simulator sickness can be a bias factor in objective evaluation of human sensibility which also, uses physiological signals. That is, the changes on the parameter $\alpha$/total and $\beta$/total, and on activation level of sympathetic nervous system from simulator sickness can be a bias factor for evaluation of the level of pleasantness and tension. Therefore the effort on improving the analysis by minimizing or eliminating the bias factors should be done for better and accurate sensibility evaluation in simulator environments.

• Journal of ILASS-Korea
• /
• v.19 no.1
• /
• pp.33-39
• /
• 2014

Due to persist of high oil prices, LPG price stabilization and CNG modification project will be conducted. Present study describes the fuel efficiency and $CO_2$ emission characteristics on driving cycle mode and ignition advance condition change of CNG/LPG Bi-Fuel vehicle. In case of LPG Base and CNG Base condition, considerable $CO_2$ emissions are generated within range of high acceleration on FTP-75 and HWFET driving mode. However previous phenomena does not appear in CNG fuel $10^{\circ}CA$ and $15^{\circ}CA$ spark advance condition. As a result of analyzing the experimental data CNG $S/A10^{\circ}CA$, CNG $S/A15^{\circ}CA$, CNG Base, and LPG Base sequentially measured high fuel economy and low $CO_2$ emission characteristics.

• International Journal of Precision Engineering and Manufacturing
• /
• v.4 no.6
• /
• pp.44-49
• /
• 2003

The morphological analysis of wear debris can provide early a failure diagnosis in lubricated moving system. It can be effective to analyze operating conditions of oil-lubricated tribological system with shape characteristics of wear debris in a lubricant. But, in order to predict and recognize an operating condition of lubricated machine, it is needed to analyze and to identify shape characteristics of wear debris. Therefore, If the morphological characteristics of wear debris are recognized by computer image analysis using the neural network algorithm, it is possible to recognize operating condition of hydraulic driving members. In this study, wear debris in the lubricating oil are extracted by membrane filter (0.45$\mu\textrm{m}$), and the quantitative values of shape parameters of wear debris are calculated by the digital image processing. This shape parameters are studied and identified by the artificial neural network algorithm. The result of study could be applied to prediction and to recognition of the operating condition of hydraulic driving members in lubricated machine systems.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.628-635
• /
• 2009

To assure the safety of urban railway train, it is necessary to observe the specified driving principles under an essential condition during running on tracks. These principles arises from a great deal of experience for a long time and include safe distance between trains, the railway signaling, block system, regular block of the highest priority and driving prohibition of simple railway vehicle in the main track, etc. Therefore, it is important to apply these principles to domestic urban railway driving regulations and railway vehicle driving regulations. However, domestic urban railway administrator established his own operation rules within the regulation. In this study, domestic urban railway administration's own rules are examined and the appropriate driving regulation on the safe driving principles is proposed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.20 no.11
• /
• pp.953-958
• /
• 2007

In this paper, multilayer actuator structured-ultrasonic nozzle and resonant inverter driving circuit were manufactured, respectively. Its electrical properties were investigated. Multilayer actuator structured ultrasonic nozzle was fabricated using PMN-PNN-PZT ceramics showing excellent piezoelectric characteristics. In order to drive ultrasonic nozzle, resonant PWM inverter was used. The purpose of this study is to find the optimal driving condition of ultrasonic nozzle. Accordingly, electrical and temperature characteristic of multilayer ultrasonic driving system were investigated by experiments as a function of the series resonance inductance. The driving current of ultrasonic nozzle showed the maximum current of 27 mA. Also, the surface temperature of ceramic vibrator showed $44^{\circ}C$ at driving time for 20 min. The ultrasonic nozzle was stably operated in the case of driving for more than 20 min.