• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.9-14
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• 2006

This study presented the feasibility of R152a refrigerant as an alternative of R134a which is used in the current automobile air conditioning system. The performance of air conditioning system installed in the actual vehicle was tested using the climate wind tunnel. The experiments were conducted at various refrigerant charge quantities and various driving conditions such as city traffic, highway traffic and parking. Same components and lubricant were used for both R134a and R152a system. The effects of air set values of thermal expansion valve on the performance were also investigated. In case of the R152a system, refrigerant charge quantity can be reduced about 20%, better performance and superior compressor durability is expected due to the lower discharge pressure compared to the R134a system.

• Proceedings of the Safety Management and Science Conference
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• 2010.11a
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• pp.41-61
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• 2010

With increasing the quality of life in proportion to the national income, we have had cars as more convenient and safe means of transportation for a long time. The more we have the benefits from cars, the more seriously we should consider problems such as the destruction of the environment by air pollution, traffic accidents, parking problems, traffic congestion, etc. as social cost caused by the increase of cars. Among them, the traffic accidents are very serious, especially the accidents of the business cars occurs five times more than those of the private cars. Therefore if we analyze the cases of the various kinds of syst.em, test the results and apply them to business cars, we will reduce the traffic accidents of business cars.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.1
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• pp.124-130
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• 2001

This paper presents a methodology on automation of a trailer type vehicle which consists of two parts: a tractor and a trailer. Backward moving and parking control is very important to automate this type of vehicle. It is difficult to control the motion such a trailer vehicle whose dynamics in non-holonomic. Therefore, in this paper, the modeling and parameter estimation of the system using a RCGA(real-coded genetic algorithm) is proposed and a backward path tracking control algorithm is then obtained. The simulation results verify the effectiveness of the proposed method.

• Journal of Engineering Education Research
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• v.13 no.5
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• pp.20-24
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• 2010

The total number of deaths by traffic accidents is decreasing every year in our country. However, in 2009, children died in traffic accidents at a rate of 2.3 deaths per 100,000 children, which was higher than the average of OECD countries (1.9 deaths per 100,000 children). In particular, traffic accidents are showing rapid increase in school zone during the past 2 years because of problems in the designation and management of school zone. Traffic safety facilities such as road sign, reflector mirror, speed bump have the ultimate limit of vehicle accidents prevention. Thus, in school zone, children safety is still not guaranteed due to illegal parking and the absence of driver's awareness of safety. Therefore, In order to protect children from traffic accidents within school zones, we have realized a safe school zone system, which enables the drivers to better know the intended school zones and creates pedestrian environment through unmanned monitoring camera, using LabVIEW.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2000.05a
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• pp.11-15
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• 2000

This paper provides a basic study on automatic of a trailer type vehicle which consists of two parts such as a tractor and a trailer Backward moving and parking control is very important to automate this type of vehicle. However it is very difficult to control such their motion since a trailer type vehicle is a non-holonomic system. Therefore in this paper we propose the backward path tracking control algorithm for a trailer type vehicle. And also this paper presents the results of simulation to verify the effectiveness of the proposed control algorithm.

• The Journal of Korea Robotics Society
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• v.5 no.1
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• pp.55-63
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• 2010

This paper describes performance improvement of GPS/DR Integration system using area decision algorithm and vehicle movement information. In GPS signal blockage area, i.e., tunnel and underground parking area, DR sensor errors are accumulated and navigation solution is gradually diverged. We use the car movement information according to moving area to correct the DR sensor error. Also, vehicle movement is decided as stop, straight line, turn and movement changing region through DR sensor data analysis. The car experiment is performed to verify the supposed method. The results show that supposed method provides small position and heading error than previous method.

• Proceedings of the Korea Multimedia Society Conference
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• 2001.11a
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• pp.80-83
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• 2001

주차 관리원에 의한 주차요금 징수체계가 경영효율이 낮고 부조리의 발생요인이 높아 기계화설비의 도입에 의한 주차요금징수 자동화시스템으로의 변환이 요구되고 있다. 본 논문에서는 무선 단문 서비스(SMS ,Wireless Short Message Service)와 개인 휴대 정보 단말기(PDA : Personal Digital Assistant)를 이용하여 광역에 걸쳐 설치되어 있는 주차 관제용 기계화 설비를 원격으로 관리하며 최소의 주차 관리요원으로 넓은 주차시설의 효율적인 관리를 가능하게 하는 기계화설비에 대한 원격관리 시스템을 설계 및 구현하였다.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2003.11a
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• pp.291-298
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• 2003

Recently, load/unload(L/UL) process is applied to a computer information storage device due to its advantages such as lower power consumption, larger data zone, simpler fabrication of disk for no bumped parking zone, and rarer contact between the slider and media. An analysis of the transient motion for the slider is very important to design an air bearing surface (ABS) of the slider to secure the stable performance of the system. During the L/UL process, however, there are several issues occurred such as contact or collision between slider and media. Sometimes this will cause the system failure. In this study, the dynamics of the slider during the loading process are investigated through a numerical simulation using FEM analysis and experiment.

• Journal of Ubiquitous Convergence Technology
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• v.1 no.1
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• pp.42-46
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• 2007

In this paper, we proposed an efficient short address allocation mechanism for WiBEEM devices using NAA(Next Address Available) algorithm. The proposed addressing mechanism is based upon the NAA information that is delivered over the beacons every time it is transmitted at the beginning of each super-frame. The NAA-based addressing mechanism is not a systematic way of allocating short addresses to newly joining devices and thus tree-routing cannot be supported. However, it has great advantages when U-City core services including U-Parking Lot System or ATIS(Advanced Traveler Information System) services that require high-speed mobility are considered. Moreover, the proposed addressing mechanism can provide significant expandability of the wireless network to various applications and fast device discovery.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.217-218
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• 2017

Residential apartment underground structures are being utilized for many purposes such as parking lots, community centers, fitness centers, etc. for efficient use of space. However, there are increasing problems of leakage due to various environmental and deterioration conditions. This paper proposes the development of an information network system which can serve as a base to provide solutions, alternatives and technical information for leakage prevention and effective design at the beginning of the construction stage.