• Journal of the korean Society of Automotive Engineers
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• v.10 no.2
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• pp.23-38
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• 1988

자동차정비기술 및 기능숙련을 보다 빨리 함양시키기 위한 방법중 필요한 작업시간을 최대로 유지시키고 평소 작업시간에 지장이 없는 상태에서 어떻게 하면 효율적인 교육훈련을 실시할 수 있느냐가 바로 문제의 핵심이라 하겠다. 그러므로 본 연구는 이러한 점에 착안하여 자동차정비사업체에 종사하고 있는 정비기능사에 대한 직장내교육훈련(OJT)제도운영실태를 분석하여 애로사항과 문제점에 대한 대책을 수립하여 자동차정비사의 기술능력향상을 위한 OJT제도 운영개선방향을 제시함을 목적으로 하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.163-170
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• 2016

Regulations for the exhaust gas of diesel vehicles are being strengthened every year. Recently, diesel emission regulations for HC, CO, NOx, and particulate matter (PM) have been subject to very strict standards. In the future, the regulation of PM is expected to become stricter. Accordingly, diesel particulate filters (DPFs) have been applied to most diesel vehicles for PM reduction. With increasing engine mileage, ash and soot from the engine exhaust gas accumulate inside the DPF. This accumulation can damage the DPF or degrade engine performance. Therefore, efficient cleaning of the DPF is critical for the maintenance of the engine. If the DPF is well managed through regular cleaning, it can improve the power and fuel economy of the engine and reduce maintenance costs. Therefore, this study was performed to develop a high-efficiency cleaning method for DPFs and an apparatus that can more effectively clean out the accumulated ash and soot.

• Journal of Practical Engineering Education
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• v.7 no.2
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• pp.125-134
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• 2015

The purpose of this study is to develop semiconductor equipment maintenance technician train program for the effective train of professional maintenance technician in the semiconductor industry. To achieve the purpose, both of the actual condition survey and the literature investigation had been proceeded for the prediction of educational train manpower requirements in the field of semiconductor equipment maintenance in and outside the country. In addition, tasks and education contents were also analyzed through job analysis. Based on the result, we suggest that the education program for semiconductor equipment maintenance technician train.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.5
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• pp.73-85
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• 1997

An automatic transmission is an important element of automotive power systems that allows a driving convenience. Compared to a manual transmission, however, it has a few problems in efficiency, shift feel, and maintenance. To improve these, it is imperative to understand the dynamics of automatic transmissions. This paper develops a dynamically-correct model of an automatic transmission, using the bond graph method. The bond graph method is ideally suited for modeling power systems, because the method is based on generalized power variables. The bond graph method is capable of providing correct dynamic constraints and kinematic constraints, as well as the governing differential equations of motion. The bond graph method is applied to 1-4 in-gear ranges, as well as various upshifts and downshifts of an automatic transmission, which allows an accurate simulation of an automatic transmission. Conventional automatic transmission models have no dynamic constraint, which do not allow correct simulation studies.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.4
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• pp.173-178
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• 2008

Electro-hydraulic brake system has many advantages. It provides improved braking performance and stability functions. It also removes complex mechanical parts for freedom of design, improves maintenance requirements and reduces unit weight. However, the EHB system should be dependable and have back-up redundancy in case of a failure. In this paper, the model-based fault diagnosis system is developed to monitor the brake status using the analytical redundancy method. The performance of the model-based fault diagnosis system is verified in real-time simulation. It demonstrates the effectiveness of the proposed system in various faulty cases.

• Journal of the Korean Society of Visualization
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• v.21 no.2
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• pp.34-45
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• 2023

When lithium-ion batteries operate out of the proper temperature range, their performance can be significantly degraded and safety issues such as thermal runaway can occur. Therefore, battery thermal management systems are widely researched to maintain the temperature of Li-ion battery cells within the proper temperature range during the charging and discharging process. This study investigates the cooling performance and isothermal maintenance of cooling materials by measuring the surface temperature of a battery cell with or without cooling materials, such as silicone oil, thermal adhesive, and phase change materials during discharge process of battery by the experimental and numerical analysis. As a result of the experiment, the battery pack filled with phase change material showed a temperature reduction of 47.4 ℃ compared to the case of natural convection. It proves the advanced utility of the cooling unit using phase change material that is suitable for use in battery thermal management systems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.4
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• pp.1568-1575
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• 2013

There has been an increasing interest in the market of vehicle maintenance and repair equipments to decrease air pollution. However, most of the existing air conditioning system equipment in Korea have poor performance as well as non-protection against air pollution. The purpose of this paper is to develop the monitoring technology of recovering and recharging refrigerant for air conditioning system, and also to develop its related diagnostic system. This technology and system can supply the exact amount of refrigerant from the charger to the air conditioning system by precisely diagnosing and monitoring their statuses. This technology can also control recovering and recharging of refrigerant exactly by altering the recovering pressures of refrigerant according to circumstance temperatures.

• International Journal of Automotive Technology
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• v.6 no.5
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• pp.501-506
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• 2005

With the respective collapse characteristics of aluminum and CFRP (Carbon Fiber Reinforced Plastics) tubes in mind, axial collapse tests were performed for aluminum/CFRP compound tubes, which are composed of square or circular shaped aluminum tubes wrapped with CFRP outside. In this study, the collapse modes and the energy absorption characteristics were analyzed for aluminum/CFRP compound tubes which have different fiber orientation angle of CFRP. Fracture modes in the aluminum/CFRP compound tubes were rather stable than those in the CFRP tubes alone, probably due to the ductile nature of the inner aluminum tubes. The absorbed energy per unit volume of the aluminum or the aluminum/CFRP compound tubes was higher than that of CFRP tubes. Meanwhile, the absorbed energy per unit mass, for the light-weight design aspect was higher in the aluminum/CFRP compound tubes than in the aluminum tubes or the CFRP tubes. The energy absorption turned out to be higher in circular tubes than in square tubes. Beside the collapse modes and the energy absorption characteristics were influenced by the orientation angle, and the compound tubes took the most effective energy absorption when the fiber orientation angle of CFRP was 90 degrees.

• Journal of Practical Engineering Education
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• v.8 no.2
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• pp.91-94
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• 2016

This study is focused on the development and application of automotive lighting system simulator device to help understanding of the repair and overhaul, electrical instrumentation and automotive circuit checks the contents of the automotive electrical system. The purpose of this study is to define the circuit numeracy, circuit repair preparation skills, detachable power, circuit analysis capabilities, inspection and measurement capability, and repair (problem solving) skills, through the cultivation of clean ability to increase the understanding of electrical equipment maintenance circuitry to verify the improvement of the repair. Automotive electrical device requires understanding of the invisible parts, and understanding of the various symbols and complex circuitry to measure the basic checks and repair are indispensable. This paper would likely contribute to help students to gain more interest in the fields that they feel difficult such as basic skills which necessary to cultivate a variety of electrical equipment fault diagnosis of the basic knowledge needed for electric cars practical.

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.4
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• pp.136-147
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• 2021

Autonomous driving-related technologies are developing step by step by applying the degree of driving. It is essential that operational management technology for roads where autonomous vehicles move should also develop in line with autonomous driving technology. However, in the case of road operation management, it is currently managed using only two-dimensional information, showing limitations in the systematic operation management of lane and facility information and maintenance. This study proposed a plan to construct an operation management system architecture capable of 3D spatial information-based operation management by designing a convergence database that can process real-time big data with high-definition road map data. Through this study, when using a high-definition road map based operation management system for lane and facility maintenance in the future, it is possible to visualize and manage facilities, edit and analyze data of multiple users, link various GIS S/W and efficiently process large scale of real-time data.