• Korean Journal of Construction Engineering and Management
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• v.9 no.2
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• pp.99-107
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• 2008

Rapidly increasing automobile supply rate according to improved economic level of life makes lack of parking space of apartments. Even though the initial design of parking space compiled with old regulations, it may not observe either new laws or requirement of inhabitants. Even if old apartments have no structural durability problem, outworn facilities and insufficient parking area may be a main reason for reconstruction. It causes waste of national resources and makes recycling issues. Additionally, irregularly parked cars make traffic obstruction to a fire engine and result in many fire accident victims. Parking problems of apartments are not only inconvenience but also serious safety issues. From these points of view, remodeling only for parking area expansion is necessary to avoid overall reconstruction of apartments. The purpose of this study is to suggest a retaining wall selection method for apartments underground parking lots expansion without evacuation of resident people. Effect factors to select retaining wall system are analyzed and weight values are calculated by applying AHP. One selection method of retaining wall is proposed by evaluating applicability and its sensitivity analysis is executed. This selection method is expected to help decision-making of retaining wall system selection.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.4956-4962
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• 2012

Among the various parts of automobile, automotive seat is the most fundamental item that ride comfort can be evaluated as the direct contact part with human body. Automotive seat must have the sufficient rigidity and strength at the same time with ride comfort. In this study, cushion frame and back frame at car seat are modelled with 3D. There are structural simulation analyses about 3 kinds of tests on torsion strength, vertical load strength and back frame strength. In the analysis result, the initial total deformation and the permanent total deformation has the maximum values of 5.4821 mm and 0.02539mm respectively at the torsion strength test of cushion frame. Total deformations at front and rear end parts of cushion frame become the values of 2.1159mm and 0.0606mm respectively at the test of vertical load strength of cushion frame. In case of more than this load, the maximum value of total deformation also becomes 3.1739mm. The maximum value of total deformation becomes 0.18634mm at 3 kinds of the strength tests on back frame. By the study result of no excessive deformation and no fracture cushion frame and back frame at automotive seat, the sufficient rigidity and strength to guarantee the safety of passenger can be verified.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.9
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• pp.713-718
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• 2015

The purpose of this study is to realize compressor-performance improvements in the fuel economy of an automotive air-conditioning system. We conduct cooling performance tests in a compressor calorimeter test stand. To improve the cooling performance, we investigate the increase in the suction flow rate and the decrease in the discharge dead volume. Based on the results of the test, we found that the cooling capacity and the coefficient of performance (COP) of the compressors were improved as follows. The cooling performance improved greater at high speeds than low speeds in the case of an increase in the suction flow rate increase, and it improved more at low speeds than at high speed when there was a decrease in the discharge dead volume. When both of the above factors were included, we observed that the improvement effects were generally balanced for both high- and low-speed modes, and there was a significant improvement in the discharge temperature. The improvement was found to be about 3.2% at low speed, 8.3% at high speed during in cooling performance improvement, about 5.8% at low speed and about 6.2% at high speed in COP improvement, and there was a decrease of about $3^{\circ}C$ at low speed and a $5^{\circ}C$ decrease at high speed in discharge temperature.

• Journal of Korean Society of societal Security
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• v.3 no.2
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• pp.33-39
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• 2010

This study is to reduce the rate of drowning accident by using of buoyancy bag. People are exposed to the high risk of drowning accident when they have water leisure activities due to the lack of safety mind-set and shortage of safety products. In case of drowning accident, the rescue action is normally depending on the other people's assistance. Therefore, rescue activities which relyn the people doesn't improve the ratio of survival in the drowning accidents. The submarine specialists should use the buoyancy products to rescue the people in the drowning accident. The citizen can carry portable buoyancy product in the automobile as well as by hands anywhere and anytime. It will be effective rescue tool to save his/her life in the emergency. In addition, it will contribute to rescue other's life because it can be used immediately. There are 3 positive characteristics on the buoyancy bag. First, it is convenience. Documents and other stuffs can be kept in the bag. Second is safety. The material of buoyancy is placed in the inner of the bag. It is possible to float the person whose weight is 90 kg. Lastly, it is durability. It can be used long-term because the outer of the bag is made of anti-water material and anti-water zipper. As a result of performance analysis, it is evident that the buoyancy bag can be used to rescue the people in the drowning accident as a indirect rescue tool compared with the current other rescue products. It is recommended that the design of outer box and performance of buoyancy are required to be improved in order to contribute more to rescue people in the accident.

• Journal of the Korea Convergence Society
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• v.8 no.8
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• pp.89-94
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• 2017

This paper implements a web - based production monitoring system that can be used efficiently by small - scale manufacturers. Small-scale enterprises, especially small-sized enterprises with less than 5 employees, need an efficient production management system because productivity is important. However, in reality, the manager and the worker verbally report work orders and production, and when one of the members is absent, the delay in the work process increases. If the time required for the work process increases, the productivity will be affected and the sales of the enterprise will be affected. In this paper, we have designed and implemented a web - based production monitoring system that can be used efficiently by small - sized manufacturers with less than 5 employees. We implemented a web based browser to operate with only a browser and applied the UI for convenience of the field worker. The proposed system is applied to less than 5 automobile parts manufacturers and the system effectiveness is confirmed. The system can be economically applied to more small enterprises with only a few modifications according to the products of each company.

• Journal of Korean Society of Transportation
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• v.32 no.2
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• pp.83-92
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• 2014

Weather condition is one of the crucial factors affecting travelers' mode choice. Nevertheless, there are numerous indefinite traffic phenomena under various weather conditions. This study was conducted to verify the hypothesis that transit riderships decrease as precipitation increases. To clarify the relationship between precipitation and transit ridership, a seemingly unrelated regression model was employed with data such as daily precipitation and daily transit riderships of 3 transit modes (bus, metro, and shuttle bus) collected in Busan for recent 24 months. The estimation results show that transit riderships decreased as the daily precipitation increased when the daily precipitation is greater or equal to 10mm/day (0.169%, 0.101%, and 0.172% reduction in bus, metro, and shuttle bus riderships, respectively, when the daily precipitation increased by 1mm). When comparing the impact of precipitation on transit riderships by modes using a cross-equation parameter restriction test, the decrease in metro ridership is relatively insensitive to the change in precipitation. However, the negative coefficient of precipitation in the metro ridership estimation model indicates that the transit users in Busan may alter their mode to taxi or automobile and/or may give up the trip itself in bad weather condition.

• Science of Emotion and Sensibility
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• v.13 no.2
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• pp.309-316
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• 2010

This paper proposes healthcare bathing system for improving the multisensory function and not washing. We designed various types of bathtub for developing bathing system. This system consists of whirlpool bathtub for multisensory stimulation, a cover of bathtub with visual-auditory stimulation function, a small size PC for main control, touch panel, digital multimedia broadcasting (DMB), color-changeable LED mood lighting system for improving visual sensibility and speaker. We investigate the effects on autonomic nervous system during bathing with healthcare bathing system for improving the multisensory functions. To analysis physiological parameter, body temperature, blood pressure, intraocular pressure and heart rate variability (HRV) were measured before, during and after bath using healthcare bathing system. Experiments were performed on partial immersion bath and the water temperature was kept $39{\pm}0.5^{\circ}C$. The body temperature and the heart rate variability of the subject were measured every 5 minutes before, during, and after the bath. In analysis of HRV, the parasympathetic nerve increased from starting bath and decreased after 15 minutes. So the subjects felt comfortable at 15 minutes after starting bath. Blood pressure decreased to 16mmHg maximumly however pulse increased. Bath using healthcare bathing system for improving the multisensory functions affects positively the circulation of the blood. From this results, it leaves something to be desired in evaluation of serviceability and physiological analysis using the healthcare bathing system, however, we expect to analyze more clearly the relationship between the serviceability of product, physiological change and sensibility by various physiological parameters.

• Journal of Distribution Science
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• v.14 no.5
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• pp.71-80
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• 2016

Purpose - In case of automobile parts, there has been a lot of progress in the study on supplier development plans and SCM in industrial progress study as well as on the relationship between ERP and SCM. But supplier development program providers have researched on SCM performance in accordance with the interests of the supplier development program most, thus, buyers were knowledgeable about the earlier program performance. Therefore, the purpose of this study is to prove correlation factor, supplier factor, purchaser factor affecting SCM performance and ERP activating diffusion through the process of supplier development. Supplier development maturity formation model is considered important variables as mediators related to the procedure. Finally, the performance formation model of the supplier development maturity through supplier development factor would be presented as the outcome of this study. Research design, data, and methodology - Data gathering was as follows: questionnaires were delivered to 87 companies that have business connection with H Company. The empirical research to test our hypothesis was grounded on statistical analysis (adapting SPSS 19.0 & AMOS 19.0). The hypothesis is that the supplier development factor variables consist of correlation factor, supplier factor, purchaser factor, and have non-negative effects on the next variables: mediators such as supplier development maturity; and the supplier development maturity variables have a positive effect on the next variables: ERP activating diffusion, ERP activating diffusion has a non-negative effect on supply chain performance. We experimented the hypothesized model using path analysis with latent variables. Results - First, it was known that cooperation

, reliability

, comprehension on the purpose of SDP

, adaptation of change

, knowledge transfer program

, have significant positive effects on supplier development maturity. Second, supplier development maturity has positive effects significantly on ERP activating diffusion

. Finally, the causal relationships from ERP activating diffusion to SCM performance were significantly accepted. Its significance, as through the hypotheses, presented a structural model for the elaboration, suppliers develop maturity, and ultimately SCM performance that affect ERP leveraging spread beyond the concept of maturity of information system. Therefore, it was a mainstay of research on the existing ERP has they believed. Conclusion - First, with the fast changes in business circumstances, company should get the right information to implement SCM appropriately. For successful SCM, firms should understand the supplier development maturity formation and ERP activating diffusion. Second, supplier development factor has significant effects on supplier development maturity. Third, mediator such as supplier development maturity significantly affects ERP activating diffusion. Finally, ERP activating diffusion has significant impacts on SCM performance. This study makes a meaningful contribution to further appreciation on how supplier development maturity formation affects SCM performance. This study shows implications. First, there would not have been dealt with introducing the concept of supplier development maturity. Second, through empirical analysis and provider factors, the providers will develop the maturity that affect interactive factors between purchaser and supplier.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.4
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• pp.42-50
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• 2009

Ubiquitous computing technology is widely used in not only our everyday lives but also in education, medical care, military, environment and administration. RFID system, the basis of ubiquitous, is in the spotlight which can be an alternative solution of a bar code recognition system and magnetic system as they basically have practicality and security issues. An electronic authentication named smart-key system is recently concerned by an alternative solution of the security unit for an automobile. RFID system which has a general purpose is also in the limelight by an application technology. In this paper we designed vehicle smart key system with general-propose RFID system that is already in use. First, we designed control unit and RFID card reader for vehicle smart key system. Then we propose an algorithm and prove that the vehicle key system is controllable by showing the result of implementing and testing, after installing. Also security level is enlarged by proposing a authentication protocol between RFID reader and control unit.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.62-68
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• 2016

The feeder cable assembly is an automotive part used for telecommunication. If it malfunctions, the control and safety of the automobile can be put at risk. ALT (Accelerated Life Testing) is a testing process for products in which they are subjected to conditions (stress, strain, temperatures, etc.) in excess of their normal service parameters in an attempt to uncover faults and potential modes of failure in a short amount of time. Failure is caused by defects in the design, process, quality, or application of the part, and these defects are the underlying causes of failure or which initiate a process leading to failure. Thermal shock occurs when a thermal gradient causes different parts of an object to expand by different amounts. Thermal shock testing is performed to determine the ability of parts and components to withstand sudden changes in temperature. In this research, the main causes of failure of the feeder cable assembly were snapping, shorting and electro-pressure resistance failure. Using the Coffin-Manson model for ALT, the normal conditions were from Tmax = $80^{\circ}C$ to Tmin = $-40^{\circ}C$, the accelerated testing conditions were from Tmax = $120^{\circ}C$ to Tmin = $-60^{\circ}C$, the AF (Acceleration Factor) was 2.25 and the testing time was reduced from 1,000 cycles to 444 cycles. Using the Bxlife test, the number of samples was 5, the required life was B0.04%.10years, in the acceleration condition, 747 cycles were obtained. After the thermal shock test under different conditions, the feeder cable assembly was examined by a network analyzer and compared with the Weibull distribution modulus parameter. The results obtained showed good results in acceleration life test mode. For the same reliability rate, the testing time was decreased by a quarter using ALT.