• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.16 no.1
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• pp.84-91
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• 2020

The APR1400 reactor stud holes can be stuck due to high temperatures, high pressure, prolonged engagement, and load changes according to pressure changes in the reactor. Threaded surfaces of a stud hole should be cleaned for the sealing of pressure in reactor vessel by removing any foreign materials which may exist in the stud holes. Human workers can access to the stud hole for the cleaning of stud holes manually, but the radiation exposure of human workers is increased. Robot is an effective way to work in hazardous area. So we introduced robot for the cleaning of stud holes. Localization of mobile robots is generally based on odometry, but with increased mileage, position errors can be accumulated. In order to eliminate cumulative error and to ensure stability of its driving, laser sensors and new control algorithm were utilized. The distance between the robot and the wall was measured by laser sensors, and the control algorithm was implemented so as to travel the desired trajectory by using the measured values from sensors. The performance of driving and hole sensing were verified through field application, and mobile robot was confirmed to be applicable to the APR 1400 NPP.

• Journal of Distribution Science
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• v.18 no.1
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• pp.35-45
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• 2020

Purpose- This study examines the multi-mediation effect of personal self-congruity and social self-congruity to perceived value and brand attitude on aircraft customers in China. Research design, data and methodology- Survey was conducted on Chinese citizens who had flown via Chinese airlines and lived mainly in the Yangtze River delta. 727 cases were analyzed. SPSS 22.0 and AMOS 24.0 were used to analyze the data. Results - First, perceived economic value has a positive impact on personal self-congruity and social self-congruity but has no effect on brand attitude. Second, perceived functional value has a positive impact on personal self-congruity, social self-congruity, and brand attitude. Third, based on this, perceived economic value is not directly related to brand attitude. However, there is a relationship between perceived functional value and brand attitude, with personal self-congruity and social self-congruity having mediation effects. Conclusions - The Results show that perceived economic and functional value such as competitive airfare, mileage membership, check-in processes, diversified vouchers and coupons, and also basic services such as flight security and flight attendant service having an effect on personal self-congruity. To improve consumer brand attitude, airlines should take into consideration personal self-congruity factors such as their values and lifestyles, and their social self-congruity factors such as their social status and social security.

• Journal of Digital Contents Society
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• v.16 no.2
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• pp.317-324
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• 2015

In this paper, we analyze the optimum moving speed of taxi for maximum revenue. In the analysis, we vary taxi speed from 5km/h through 80km/h to see how revenue of a taxi varies applying the practical gas mileage of LPG taxi and taxi fare system in Korea. From the results of the analysis, we see that the probability that a taxi meets passengers goes high as taxi speed gets fast, however the fuel cost also goes up. We also obtain the optimum speed for the maximum revenue according to passenger distribution while varing moving speed.

• Fashion & Textile Research Journal
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• v.16 no.4
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• pp.596-603
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• 2014

The purpose of this study was to find affecting consumer's usage motivation on purchase satisfaction and repurchase intension when purchasing fashion products in social commerce. The data were collected via a self-administered questionnaire from 239 male and female who living in Busan with experience in social commerce purchasing fashion products. Using SPSS 20.0 and AMOS 20.0 package, Cronbach's ${\alpha}$, a confirmotory factor analysis and a structural equation modeling analysis were performed. The results are as follows. Hedonic, economical efficiency and interaction without information provide subjective norms significantly influenced the purchase satisfaction. And aforementioned subjective norms significantly influenced repurchase intension, too. The purchase satisfaction positively influenced the repurchase intension. Therefore, social commerce sellers of fashion products ought to offer variety price benift and promotion to raise the purchase satisfaction and repurchase intension. To offer variety price benift, they should respond sensitively to the price set by comparing prices with other sellers. And promotion to raise the purchase satisfaction and repurchase intension need to consider such variety of missions, discount coupons or event and mileage. In addition, they should develop customer service system for interaction with customer and connect to the repurchase increases the purchass satisfaction through faster customer response to the product information or sales, service.

• Journal of Energy Engineering
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• v.25 no.4
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• pp.170-175
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• 2016

An internal combustion engine is the most widely used power source for an automobile. In order to resolve environmental problems resulting from the use of internal combustion engines, environmentally friendly automobiles such as hybrid, electric, and air-engine vehicles are being developed. The share of hybrid vehicles using battery or pure electric vehicles, which are not popular, is gradually increasing. Compared to an electric vehicle, which uses an electric motor, air-engine vehicles, which use compressed air, have hardly been developed. In this study, a compressed air engine with a scroll expander is introduced, and the potential mileage of an automobile utilizing this engine is theoretically calculated.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.854-859
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• 2008

In a railway vehicle, contact between wheel and rail is a peculiar characteristic and variations of wheel and rail profile influence on the dynamic characteristics of railway vehicle. Thus the variations of the wheel and rail profile are very important in railway dynamics. Recently a research relating to active steering to improve the curving performance of vehicle is progressing actively at home and abroad. In this field, a pre-study for the wheel/rail contact geometry is needed and especially the variation of the wheel/rail contact geometry with wheel wear is the key design parameter to develop the controller of the active steering bogie. In this paper, we have experimentally studied to analyze the variation of the wheel/rail contact geometry with wheel wear as a pre-study to develop the active steering bogie for electric multiple unit (EMU). For this, we have made an experiment with EMU operating in curving area. We have measured the wear profiles of the wheel of the test vehicle and analyzed the wheel/rail contact geometry with a mileage of the test vehicle. In experiment with test vehicle, we have got the useful data to design the steering controller of the wheelset.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.103-104
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• 2006

Wear of valve seating face and seat insert seating face influence the performance of engine, so they are important. To manufacture good quality valve and seat insert which have wear resistance the relations between wear factors and wear of the two seating faces have to be inspected. Cycle number is one of the important wear factors wearing the two seating faces and it can translate into mileage in rear car. But little is blown. Test variable is only cycle number and the cycle numbers are $2.0{\times}10^6,\;4.0{\times}10^6\;6.0{\times}10^6,\;8.0{\times}10^6$. And the other test conditions were fixed. Rmax of valve seating face and seat insert seating face increase linearly as cycle number is increased. Rmax of valve seating face were smaller than seat insert seating face in each cycle number. Reaction production by tribological reaction and sliding wear was found on the two faces.

• Journal of Korean Society for Quality Management
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• v.10 no.1
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• pp.27-42
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• 1982

품질관리(品質管理)가 단순(單純)히 품질(品質)을 관리(管理)하는 통계적(統計的)인 수법(手法)으로서의 역할(役割)을 벗어나 경영관리(經營管理)의 새로운 시스템으로서 등장되던 1960년 전후부터 품질보증(品質保證)(quality assurance:QA)의 중요성(重要性)이 점차(漸次) 높아지게 되었다. 1959년(年)에 미국(美國)의 자동차업계(自動車業界)에서 시작(始作)된 마일에이지 보증(保證)(mileage warranty)이나, 이어서 보급된 내구소비재(耐久消費財)의 1년 보증제(保證制) 등이 QA의 발달(發達)의 계기(契機)가 되었다. 뿐만 아니라 점점 복잡화 되어가고 있는 제품(製品)에 대(對)한 안전성(安全性)이 강하게 요청(要請)되고 있다거나, 소비자(消費者)의 제품(製品)에 대(對)한 뉴스가 다양화(多樣化)되어 온것도 QA의 용요성(用要性)이 일반(一般)에게 인식(認識)되기 시작(始作)한 요인(要因)이었다고 생각한다. 이때부터 품질보증(品質保證)이라는 말이 널리 사용(使用)되어 왔다. 그러나 그 말을 사용(使用)하는 사람에 따라 뉴안스를 달리하는 경우가 많다. 즉 품질보증(品質保證)이라는 말의 해석(解釋)이 구구하다. 품질보증(品質保證)이란 무엇을 의미(意味)하는가, 그리고 품질보증(品質保證)의 방법(方法)은 어떤 것인가에 대(對)해 부족(不足)하나마 평소(平素)에 가지고 있던 생각을 여기에 정리(整理)해 볼까 한다.

• International Journal of Automotive Technology
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• v.4 no.2
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• pp.101-108
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• 2003

There are a lot of factors that influence automotive fuel economy such as average trip time per kilometer, average trip speed, the number of times of vehicle stationary, and so forth. These factors depend on road conditions and traffic environment. In this study, various driving data were measured and recorded during road tests in Seoul. The accumulated road test mileage is around 1,300 kilometers. The objective of the study is to identify the driving patterns of the Seoul metropolitan area and to analyze the fuel economy based on these driving patterns. The driving data which was acquired through road tests was analysed statistically in order to obtain the driving characteristics via modal analysis, speed analysis, and speed-acceleration analysis. Moreover, the driving data was analyzed by multivariate statistical techniques including correlation analysis, principal component analysis, and multiple linear regression analysis in order to obtain the relationships between influencing factors on fuel economy. The analyzed results show that the average speed is around 29.2 km/h, and the average fuel economy is 10.23 km/L. The vehicle speed of the Seoul metropolitan area is slower, and the stop-and-go operation is more frequent than FTP-75 test mode which is used for emission and fuel economy tests. The average trip time per kilometer is one of the most important factors in fuel consumption, and the increase of the average speed is desirable for reducing emissions and fuel consumption.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.6
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• pp.649-659
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• 2016

This paper describes control algorithm and control structure of vehicle control unit for range-extended electric vehicle equipped with engine-generator system, and specially presents methods which determine optimal operating points and decreases a vibration or a shock for operating the engine-generating system. The vehicle control algorithm is consisted of several parts which are sequence control, calculation of wheel demand torque, determination of operating points, and management of operating points and so vehicle controller has be made possible to efficiently manage calibration parameters. The control algorithm is evaluated by driving test modes, launching performance and operating engine-generator system and so on. In conclusion, this paper present methods for extending a mileage, improving a launching performance and reducing vibration or shock when the engine-generating system is starting or is stopping.