• 비파괴검사학회지
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• 제30권3호
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• pp.271-281
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• 2010

Brazing fitting which is one of the aircraft hydraulic power system components is widely used for saving weight and achieving higher reliability. Any inherent defects or damage of fitting can cause system failure and/or physical damage of human body due to highly pressurized fluid. Radiographic testing(RT) technique and additional micro-structure investigation on cut-away surfaces have been accomplished to find out some defect-like-inhomogeneity in the fittings. The radiography results showed that some defect-like-inhomogeneity existed inside body. Additional micro-structure investigation on cut-away surface reveals that the inhomogeneity is due to internal voids. In this study, it can be is said that RT technique can be a useful tool for field acceptance test of hydraulic brazing fitting in short time.

• 비파괴검사학회지
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• 제29권2호
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• pp.130-136
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• 2009

터빈은 원자력발전소의 주요기기로서 고온 고압하에서 고속회전으로 인해 신뢰성 있는 검사가 요구된다. 터빈의 가동중검사의 경우 블레이드가 조립된 상태에서 검사가 수행되며 구조적 복잡성으로 인하여 탐촉자의 접근이 제한되며, 신호 해석이 매우 어렵다. 본 연구에서는 신뢰성 높은 신호해석을 위하여 실제 터빈과 크기 및 형상이 동일한 mock-up을 제작하였다. 터빈의 key와 내표면부의 결함탐상을 위해 pulse-echo 및 TOFD 기법을 개발하였고, dovetail 검사를 위하여 위상배열 초음파탐상기법을 개발하였다. 개발된 기법들을 가동중 터빈 검사에 효율적으로 적용하기 위해 자동화 검사 scanner를 제작하였으며, 현장적용을 통하여 신뢰성을 검증하였다.

• 문화기술의 융합
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• 제7권2호
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• pp.377-388
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• 2021

세계적으로 공유경제 시장이 성장함에 따라 최근 국내에도 다양한 공유 서비스들이 등장하고 있다. 국내 공유 모빌리티 산업을 대표하는 서비스 중 하나인 서울시 무인 공공자전거 대여 서비스 '따릉이'는 높은 인지도와 이용률에 비해 따릉이 대여에 필수 매개체인 따릉이 모바일 어플리케이션의 사용성은 개선되지 않아 사용자의 불편함을 초래한다. 본 연구는 따릉이 주 이용자인 20~30대를 대상으로 사용성 평가 (Usability testing)와 심층 인터뷰를 진행하였다. 그 결과 따릉이 모바일 어플리케이션이 갖는 문제점을 파악하였으며, 이를 바탕으로 따릉이와 같이 공공성을 갖는 공유 모빌리티 서비스의 디자인 고려사항을 제안하였다. 이는 공유 모빌리티 서비스의 사용자 경험 향상에 기여할 것으로 기대된다.

• 한국자동차공학회논문집
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• 제11권3호
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• pp.209-213
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• 2003

It is advantage of accelerated vibration testing to compress service exposures to operating vibration into a reduced laboratory test by increasing the amplitude or frequency of the applied input excitations. This paper proposes an accelerated test method to estimate the high-cycle fatigue life under random excitation. The method consists of conducting a test with amplified input excitation and extrapolating linearly the lift in the accelerated condition into the real lift in field condition. The extrapolation is carried out applying the high-cycle irregular excitation fatigue theory including the rainflow counting, Miner’s damage accumulation rule, and Goodman’s mean stress correction. As a verification, those estimated lift is compared with that acquired by experiment f3r the simple case of spot welding specimen with good agreement. This testing procedure will provide an useful scheme that can reduce testing period associated with developing time schedule of new product.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.836-839
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• 2006

Telematics, one of the so-called New Growth Engine of IT839, is a leading IT service where wireless internet service represented by information and mobility is extended to the area of transportation. To provide telematics service, Telematics service provider have to connect with various Contents Provider or Service Provide server - for example - LBSS(Location Based Service Server), ASPS(Application Service Provider Server), TELICS(TELematics Information Center Server), GMS(Geo-mobility Server), WTPS(World Telematics Protocol Server) and MAUS(Map Air Update Server). Presently, It is nearly impossible or very difficult for the company that are manufacturing and testing telematics device to develop and test telematics solution without connecting Telematics Service Provider, Service Provider, Contents Provider. And, it is very difficult to connect in TSP, CP, SP having the product to be developed. In this paper, we proposed virtual telematics service provider. The proposed Virtual Telematics Service Provider is to provide telematics services and functionalities by integrating telematics servers into TSP gateway virtually. In other words, VTSP is performs with the role of TSP, CP, SP. And the VTSP support integration of telematics servers, interfacing and monitoring between terminal and the integrated servers.

• 경영과학
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• 제29권1호
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• pp.115-129
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• 2012

Service Encounter employees play a crucial role in service delivery and building relationships with customers and their attitudes and behaviors towards customers determine customers' perceived service quality and satisfaction. Past research indicates that TQM managerial practices are a critical determinant of employee's attitude and performance in the workplace. Therefore, this study investigates a model examining the relationship among TQM, employees' attitude and service performance in a hospital. Our measurement results were acceptable in terms of reliability and validity. The statistical testing shows significance on the positive relationship in the sequential order of TQM, employee's attitude and service performance. In conclusion, the theoretical and practical implications of this study were discussed, along with its limitations.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 춘계학술대회 논문집
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• pp.591-594
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• 2000

In the recent day, fatigue life prediction techniques play a major role in the design of components in the ground vehicle industry. Full scale durability testing in the laboratory is an essential of any fatigue life evaluation of components or structure of the automotive vehicle. Component testing is particulary important in today's highly competitive industries where the design to reduce weight and production costs must be balanced with the necessity to avoid expensive service failure. Generally, 3-axis durability testing device is used to carry out the fatigue test. In this paper, The operation software for simultaneously driving 3-axis vibration testing device is developed and the displacement of the 3-axis actuator is separately calibrated by LDT Moreover, the input and output data are displayed in windows of PC controller with real time.

• 한국정밀공학회지
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• 제30권7호
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• pp.687-693
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• 2013

The service conditions of railway cars have become more difficult in recent years due to increased speed. Faulty components in the railcars may result in service interruption, or in extreme cases, derailment. Thus, it is important to diagnose and monitor the main components of railcars. Temperature monitoring is one of the basic methods used to diagnose abnormal conditions in the main components of railway cars, such as in bearings, reduction gears, and traction motors. In this study, we developed a monitoring system for the main components, using an infrared thermography technique. This technique has the advantage of infrared thermal camera imaging of temperature contours in the components. Various hardware and software components of the monitoring system are used to acquire the sensor data, to identify potential problems in railcar operation.

• 품질경영학회지
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• 제33권3호
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• pp.1-18
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• 2005

Internal marketing has been suggested as the approach for service organizations to be service-and customer-oriented; and the issues of internal service quality has been one of topics widely discussed in the internal marketing literature. The purpose of the current study is to examine the antecedents and consequences of internal service quality which is believed to increase such organizational performances as customer satisfaction, retention and revenue. In consistent with the previous studies in service marketing literatures, the current study identifies several constructs as the antecedents and consequences of internal service quality: management commitment to service quality, employee satisfaction, self-efficacy, and adaptability. The empirical study testing the causal relationships' among the constructs verifies the proposed relationships among the constructs suggested in the current study.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.483-488
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• 2001

Until now, the tensile properties of materials can be obtained just in accordance with conventional tensile testing methods which are described in several standards such as ASTM (American Society for Testing and Materials) standard and BS (British Standard). For some cases including on-service facility materials, however, the standard testing methods cannot be applicable due to the destructive testing procedure and specimen size requirement. Therefore, simple, non-destructive and advanced indentation technique was proposed. This test measures indentation load-depth curve during indentation and analyzes the mechanical properties related to deformation and fracture. In this paper, the research trend of non-destructive evaluation of tensile properties using AIS (advanced indentation system) and its application fields are reviewed and discussed.