• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.962-973
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• 2017

Concerns about an air pollution are gradually increasing at home and abroad. The automotive and fuel researchers are trying to reduce emissions and greenhouse gases of vehicles through a research on new engine designs and innovative after-treatment systems using clean fuels (eco-alternative fuel) and fuel quality improvements. In this paper, we stduy the emission characteristics of greenhouse gases on seven vehicles using gasoline, diesel, and LPG by legal test mode in domestic and abroad.(Urban mode, Highway mode, rapidly acceleration and deceleration, using air conditioner, low temperature condition) Regardless of fuels, most of the greenhouse gases tend to show the worst results in cold FTP-75 mode. In the case of A vehicles (2.0 MPI) and B vehicles (2.4 GDI) using a gasoline fuel, the factors that increase greenhouse gases are in order of a rapidly acceleration and deceleration, using air conditioner, low temperature condition. But G vehicles(LPLi) have different emission characteristics from another vehicles. In the case of A vehicles (2.0 w/o DPF) and B vehicles (2.2 with DPF) using a diesel fuel, the factors that increase greenhouse gases are in order of a rapidly acceleration and deceleration, using air conditioner, low temperature condition. However, the factor of F vehicles are in order of low temperature condition, using air conditioner, rapidly acceleration and deceleration. In conclusion, it will be an effective method to apply different technologies of emission reduction for each fuel.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.6
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• pp.116-126
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• 2013

Weather factor to affect driver's driving environment are due to changes in weather conditions is caused rainfall, snowfall, fog etc and the reducing of road capacity and because deteriorating weather could be affect the headway and vehicle speed and the decrease in lane caused by an accident occurs that was analyzed that bad weather occur congestion greater than on the clear day. Bad weather to reduce of the driver's visibility was analysed the sensitive to changes in travel speed and traffic accident to appears high characteristics according to weather conditions on the expressway(higher speed) than general road. As a result, visibility have been determined to be important factor in changes of the highway traffic flow characteristics. Therefore, in this study, we selected traffic volume and travle speed that have a major impact on high-speed expressway basic segments as importance effect factor and we selected to subject of analysis among the Metropolitan Expressway that it could be obtained certain level of traffic volume data and we studied the changing of expressway traffic flow due to change visibility after the collecting of meteorological and traffic data. In order to perform this study, data collection and analysis methods were established through the existing literature and we had selected level of visibility of the expressway and we had performed the statistical verification. Finally, we had calculated the rate of change of expressway traffic flow characteristics due to visibility and we had come up with a way to apply at capacity and service level analysis.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.1
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• pp.11-27
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• 2017

The road network system of major domestic urban areas such as city of Seoul was rapidly developed and regionally expanded. In addition, many kinds of life-lines such as electrical cables, telephone cables, water&sewerage lines, heat&cold conduits and gas lines were needed in order for urban residents to live comfortably. Therefore, most of the life-lines were individually buried in underground and individually managed. The utility tunnel is defined as the urban planning facilities for commonly installing life-lines in the National Land Planning Act. Expectation effectiveness of urban utility tunnels is reducing repeated excavation of roads, improvement of urban landscape; road pavement durability; driving performance and traffic flow. It can also be expected that ensuring disaster safety for earthquakes and sinkholes, smart-grind and electric vehicle supply, rapid response to changes in future living environment and etc. Therefore, necessity of urban utility tunnels has recently increased. However, all of the constructed utility tunnels are cut-and-cover tunnels domestically, which is included in development of new-town areas. Since urban areas can not accommodate all buried life-lines, it is necessary to study the feasibility assessment system for utility tunnel by urban patterns and capacity optimization for urban utility tunnels. In this study, we break away from the new-town utility tunnels and suggest a quantitative assessment model based on the evaluation index for urban areas. In addition, we also develop a program that can implement a quantitative evaluation system by subdividing the feasibility assessment system of urban patterns. Ultimately, this study can contribute to be activated the urban utility tunnel.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.3873-3879
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• 2010

Home service robot are not working in the fixed task such as industrial robot, because they are together with human in the same indoor space, but have to do in much more flexible and various environments. Most of them are developed on the base of the wheel-base mobile robot in the same method as a vehicle robot for factory automation. In these days, for holonomic system characteristics, omni-directional wheels are used in the mobile robot. A holonomicrobot, using omni-directional wheels, is capable of driving in any direction. But trajectory control for omni-directional mobile robot is not easy. Especially, azimuth control which sensor uncertainty problem is included is much more difficult. This paper develops trajectory controller of 3-wheels omni-directional mobile robot using fuzzy azimuth estimator. A trajectory controller for an omni-directional mobile robot, which each motor is controlled by an individual PID law to follow the speed command from inverse kinematics, needs a precise sensing data of its azimuth and exact estimation of reference azimuth value. It has imprecision and uncertainty inherent to perception sensors for azimuth. In this paper, they are solved by using fuzzy logic inference which can be used straightforward to perform the control of the mobile robot by means of the fuzzy behavior-based scheme already existent in literature. Finally, the good performance of the developed mobile robot is confirmed through live tests of path control task.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.687-692
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• 2018

In this paper, the development of an automotive thermal imaging camera providing image information for ADAS (Advanced Driver Assist System) and autonomous vehicles is described and an improved technique to enhance the details of the image is proposed. Thermal imaging cameras are used in various fields, such as the medical, industrial and military fields, for the purpose of temperature measurement and night vision. In automobiles, they are utilized for night vision systems. For their utilization in ADAS and autonomous vehicles, appropriate image resolution and enhanced detail are required for object recognition. In this study, a $640{\times}480$ resolution thermal imaging camera that can be applied to automobiles is developed and the BDE (Block-Range Detail Enhancement) technique is applied to improve the details of the image. In order to improve the image detail obtained in various driving environments, the block-range values between the target pixel and the surrounding 8 pixels are calculated and classified into 5 levels. Then, different factors are added or subtracted to obtain images with high utilization. The improved technique distinguishes the dark part of the image by the resulting temperature difference of 130mK and shows an improvement in the fine detail in both the bright and dark parts of the image. The developed thermal imaging camera using the improved detail enhancement technique is applied to a test vehicle and the results are presented.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.4
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• pp.593-607
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• 2013

The In-Vehicle-Networking(IVN) of modern cars is constituted by an small electronic control device called ECU. In the past, there was no way to be able to access the IVN of a driving car. so IVN has been recognized as a closed environment so there is no need to exist authentication protocol between devices which are to configure the internal network and to communicate with other devices. However, constant improvements made it possible to access the IVN in many different ways as the communication technology evolves. This possibility created a need for device authentication in IVN. HB-Family are representative authentication schemes in RFID environment which has similar restrictions to IVN. In this paper, we propose an implementation method of HB-Family for device authentication between ECU considering ECU has low computing power and the message field of CAN protocol has restricted size of 8 bytes. In order to evaluate the efficiency and availability of the authentication schemes adopted our method, we have evaluated the performance based on DSP-28335 device. Further, it was possible to improve the efficiency rate of at lest 10%, up to 36%, and we then analyze this result in various aspects of the IVN.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.473-480
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• 2004

Recently, they are interested in the relation between night's vehicle accidents of drivers and the dynamic visual acuity at home and aboard. So, in this research, we tried to design an optical system of the inspection equipment to measure the dynamic visual acuity. A optotype standard did to Landolt's ring with 45mm of diameter and 9mm of gap to maintain the visual acuity of 1.0 in the 30m distance. An optical structure of the inspection equipment was composed of the sequence of an observer, a plus refraction lens system, a minus refraction lens system, and an optotype that was arranged to have characteristics that the size of the first virtual image of the optotype made by the minus refraction lens system grows bigger gradually according to the optotype movement to near distance from far distance, and also the first virtual image moves to the principle plane from the focal point of the plus refraction lens system as the size of the first virtual image arranged to the inside of focal distance of plus refraction lens system grows bigger gradually. As doing these processes, we completed the optical system of which characteristic is that the position of the final second virtual image moves to 3m from 50m as the size of the second virtual image made by the plus refraction lens system maintains to be regular.

• Journal of the Korean Institute of Gas
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• v.18 no.6
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• pp.7-13
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• 2014

As the interest on the air pollution is gradually rising up at home and abroad, automotive and fuel researchers have been working on the exhaust emission reduction from vehicles through a lot of approaches, which consist of new engine design, innovative after-treatment systems, using clean (eco-friendly alternative) fuels and fuel quality improvement. This research has brought forward various main issues : whether PM emissions should be regulated for diesel and gasoline vehicles and whether gasoline and LPG powered vehicles can be further neglected from PM emission inventories. Finally, the greenhouse gas ($CO_2$, $CH_4$, $N_2O$) regulation has been discussed including automotive emission regulation. The greenhouse gas and emissions (PM) particle of automotive had many problem that cause of ambient pollution, health effects. This paper discussed the influence of LPG fuel on automotive cold startability and exhaust emissions gas. Also, this paper assessed emission characteristics due to the test temperature. These test temperature were performed by dividing the temperature of the test mode and the lowest local temperature in winter. Through this study, the correlation of cold startability, exhaust emission and greenhouse gas emission was analyzed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.224-236
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• 2017

This study analyzed the characteristics of traffic accidents among elderly drivers according to area type in Gyeonggido(urban areas, urban-rural complex areas, and rural areas). Traffic accidents caused by unsafe driving are common in all three types of areas. In urban areas and urban-rural complex areas, traffic accidents were more frequent due to traffic violations and intersection accidents, while rural areas were more affected by central lines. Urban areas and urban-rural complex areas require simpler signal exposures, such as a simple straight line, left turn, or straight line and left turn signal rather than complex signal operations, such as overlaps in a signal operation. Improvement of non-signal intersections and unprotected traffic signal processing is also needed. In order to prevent the intrusion of the central line in rural areas, the center line guard rail should be prevented from penetrating the center line, and the influence of the vehicle headlamp should be reduced in the opposite direction. It is necessary to improve the visibility by using fluorescent letters to enlarge the font size of traffic signs and road signs, particularly to increase visibility at night and prevent traffic accidents at sunset. Minimal, simplified should be provided rather than complex phrases and information.

• International Journal of Highway Engineering
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• v.20 no.2
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• pp.35-44
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• 2018

PURPOSES : The purpose of this research is to analyze the characteristics of panels that affect the evaluating results of riding quality and to evaluate the appropriateness of roughness management criteria based on ride comfort satisfaction. METHODS : In order to analyze the influence of panel characteristics of riding quality, 33 panels, consisting of civilians and experts, were selected. Also, considering the roughness distribution of the expressway, 35 sections with MRI ranging from 1.17 m/km to 4.65 m/km were selected. Each panel boarded a passenger car and evaluated the riding quality with grades from 0 to 10, and assessed whether it was satisfied or not. After removing outlier results using a box plot technique, 964 results were analyzed. An ANOVA was conducted to evaluate the effects of panel expertise, age, driving experience, vehicle ownership, and gender on the evaluation results. In addition, by using the receiver operating characteristics (ROC) curve, the MRI value, which can most accurately evaluate the satisfaction with riding quality, was derived. Then, the compatibility of MRI was evaluated using AUC as a criterion to assess whether the riding quality was satisfactory. RESULTS : Only the age of the panel participants were found to have an effect on the riding quality satisfaction. It was found that satisfaction with riding quality and MRI are strongly correlated. The satisfaction rate of roughness management criteria on new (MRI 1.6 m/km) and maintenance (MRI 3.0 m/km) expressways were 95% and 53%, respectively. As a result of evaluating the roughness management criteria by using the ROC curve, it was found that the accuracy of satisfaction was the highest at MRI 3.1-3.2 m/km. In addition, the AUC of the MRI was about 0.8, indicating that the MRI was an appropriate index for evaluating the riding quality satisfaction. CONCLUSIONS : Based on the results, the distribution of the panels' age should be considered when panel rating is conducted. From the results of the ROC curve, MRI of 3.0 m/km, which is a criterion of roughness management on maintenance expressways, is considered as appropriate.