• Structural Monitoring and Maintenance
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• 제5권1호
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• pp.129-150
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• 2018

This paper presents the structural performance monitoring of an urban footbridge located in Hangzhou, China. The structural health monitoring (SHM) system is designed and implemented for the footbridge to monitor the structural responses of the footbridge and to ensure the structural safety during the period of operation. The monitoring data of stress and displacement measured by the fiber Bragg grating (FBG)-based sensors installed at the critical locations are used to analyze and assess the operation performance of the footbridge. A linear regression method is applied to separate the temperature effect from the stress monitoring data measured by the FBG-based strain sensors. In addition, the static vertical displacement of the footbridge measured by the FBG-based hydrostatic level gauges are presented and compared with the dynamic displacement remotely measured by a machine vision-based measurement system. Based on the examination of the monitored stress and displacement data, the structural safety evaluation is executed in combination with the defined condition index.

• 제어로봇시스템학회논문지
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• 제17권8호
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• pp.783-789
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• 2011

Target tracking performance improvement using multi-sensor data fusion is a challenging work. However, biases in the measurements should be removed before various data fusion techniques are applied. In this paper, a bias removing algorithm using measurement data from multi-radar tracking systems is proposed and evaluated by computer simulation. To predict bias estimation performance in various geometric relations between the radar systems and target, a system observability index is proposed and tested via computer simulation results. It is also studied that target tracking which utilizes multi-sensor data fusion with bias-removed measurements results in better performance.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권5호
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• pp.248-252
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• 2004

Since DC ground resistance, which is a good index of the performance of a grounding system in low frequency. does not show the performance in transient state. We measured ground impedances in frequency domain ranging from 0.1 Hz to 900 KHz maximum to quantify the transient grounding performance of 4 types of grounding system. Transfer function was derived from the measured frequency-dependant ground impedance of a grounding grid. A simulation has been performed to verify the transfer function using EMTP (Electro-Magnetic Transient Program).

• 유통과학연구
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• 제14권6호
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• pp.107-118
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• 2016

Purpose - Over 90% of Domestic logistics industry is small enterprise and they are experiencing growth stagnation due to price-based competition structure rather than constructing logistics service of high added value. In order to get over this situation and pursue the development of logistics industry, strengthening its competitiveness, through inter-enterprise cooperative network build-up, would be a key alternative. Therefore, in this study, an index for measuring inter-enterprise cooperation level of Joint logistics business will be developed as a typical collaborative business model in logistics industry. Moreover, a strengthening competitiveness method suggests a developmental step and a key management index to mature in logistics industry. Research Design, Data, Methodology - This study is an index development research for measuring inter-enterprise cooperation level of logistics industry. Such a level was measured by performing a survey by targeting enterprises that participated in Joint logistics business. The targeting enterprises are typical cooperative models in logistics industry. Measurement items were developed which were based on the presented items in existing research. Question items were composed of selection type questions as answering Yes/No. They measures implementation status of corporate activity and detailed activity items measuring qualitative level. Total samples were based on 116 enterprise samples including 90 logistics enterprises and 26 shippers. In addition, by evaluating the importance for Joint logistics business recognition with personnel working level, the weight of measuring variable was extracted. This study has built an assessment tools (LPCI) on Joint logistics business cooperation level in a situation where there are no previous studies on joint logistics business, this study is meaningful for other studies. Results - As a result of analyzing LPCI presented in this study, the score of logistics enterprise was represented as 59.9 points based on full score of 100 points and that of shippers as 47.2 points and cooperation level among enterprises participated in Joint logistics business was revealed to be very low. In particular, as a result of measuring the importance between logistics enterprise and shippers, the difference by each measurement standard was represented among those enterprises. This difference is considered to be a key factor that cooperative operational conformity between logistics enterprises and shippers is represented to be low. Conclusions - As most joint logistics business, being promoted at present, is sharing facility and information with joint logistics business, it is hard to find such a joint logistics business in reality based on cooperative business model in main cooperation agents. Therefore, competitiveness of logistics industry could be strengthened by promoting joint logistics business based on their mutual cooperation among enterprises. In other words, it is to secure sustainable competitiveness of joint logistics business together with creation of new market by inter-enterprise cooperation based on integration of basic logistics business.

• 한국산학기술학회논문지
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• 제8권4호
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• pp.915-923
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• 2007

최근 들어서 병원에서도 일반 기업에서와 같이 CRM 시스템의 구축 및 운용 사례가 늘고 있다. 이러한 현상은 병원의 경영환경에도 경쟁구도가 자리 잡기 시작했고, 의료서비스 시장에서의 중심축이 공급자 중심에서 수요자중심으로 옮겨가고 있기 때문이다. 이런 환경에서 병원의 CRM 시스템의 구축 및 운용 현황에 관심을 갖는 것은 당연하다 할 것이다. 본 논문에서는 이와 같이 구축운영 중인 병원 CRM 시스템의 성과를 측정하기 위한 분석 방법에 대해서 연구하였다. 이를 위해 선행 연구를 통한 CRM의 성공 요인을 도출하고, 실증분석을 통해 요인 분석의 타당성을 분석하였다. 요인의 타당성 분석을 위해 AMOS 구조모형 분석 방법을 실시하여, 요인 분석 결과의 유의성을 높혔다. 요인 분석 결과 도출된 요인의 중요성의 측정을 위해서는 요인 간 중요도를 측정할 수 있는 AHP 기법을 적용하였다. 이는 요인의 분류 외에는 측정변수의 가중치 등의 주요 정보를 제공하지 못한다는 요인 분석 방법론의 단점을 보완하기 위함이다. 결과적으로 본 연구를 통해서 병원의 CRM 시스템의 운용 성과를 측정하기 위한 주요요인 도출과 가중치 분석을 통해 병원의 고객관리시스템의 운용 성과를 합리적으로 측정할 수 있는 지표를 제공하였다.

• 제어로봇시스템학회논문지
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• 제7권5호
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• pp.427-431
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• 2001

An on-line refractometer made of easily obtainable materials is built to determine the concentration of an alcohol solution, and its performance is examined by applying to the system of ethanol and water. Since the refractive index and the temperature are measured simultaneously, it is possible to compensate the effect of temperature which is not available with an existing on-line refeactometer. Therefore, it can be implemented in the application of process control. The experimental outcome indicates that the home-made refractometer has satisfactory reproducibility and reasonable accuracy for the industrial application.

• Safety and Health at Work
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• 제3권3호
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• pp.192-198
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• 2012

Objectives: Slip and fall accidents in the workplace are one of the top causes of work related fatalities and injuries. Previous studies have indicated that fall risk was related to postural and dynamic stability. However, the usage of this theoretical relationship was limited by laboratory based measuring instruments. The current study proposed a new method for stability assessment by use of inertial measurement units (IMUs). Methods: Accelerations at different body parts were recorded by the IMUs. Postural and local dynamic stability was assessed from these measures and compared with that computed from the traditional method. Results: The results demonstrated: 1) significant differences between fall prone and healthy groups in IMU assessed dynamic stability; and 2) better power of discrimination with multi stability index assessed by IMUs. Conclusion: The findings can be utilized in the design of a portable screening or monitoring tool for fall risk assessment in various industrial settings.

• 산업경영시스템학회지
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• 제30권4호
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• pp.182-189
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• 2007

Process Capability indices(PCIs) have been widely used in manufacturing industries to provide a quantitative measure of process performance. PCIs have been developed to represent process capability more exactly. The traditional process capability indices Cp, Cpk, Cpm, $Cpm^+$ have been used to characterize process performance on the basis of univariate quality characteristics. Cp, Cpk consider the process variation, Cpm considers both the process variation and the process deviation from target and $Cpm^+$ considers economic loss for the process deviation from target In the previous studies, only one designated location on each part is measured. System process capability index even though in single process, multiple measurement locations on each part are required to calculate the reliable process capability. In manufacturing industry, there is growing interest in quantitative measures of process variation under multivariate quality characteristics. The multivariate process capability index incorporates both the process variation and the process deviation from target or considers expected loss caused by the process deviation from target. In this paper, we compare various process capability indices and propose the application method of PCIs.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2004년도 제5회 정기학술발표대회 논문집
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• pp.414-418
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• 2004

국내 풀질시스템은 부실공사를 예방하기 위한 하나의 수단으로 출발하여 현재는 공공 건설공사를 수주하기 위해서 필수적으로 갖추어야 할 시스템으로 인식되어 왔다 이에 따라 상당수의 건설업체들이 ISO 품질경영시스템의 인증을 취득하였고 이를 기반으로 건설공사를 관리하고 있다. 그러나 이제는 공공 건설공사 입찰에 참여하는 대부분의 건설업체들이 ISO 인증을 취득하였으므로 ISO 인증은 더 이상 공공 건설공사에서 건설업체들이 수주경쟁의 우위를 점유할 수 있는 도구가 되지 못하고 있는 실정이고 이러한 과정에서 몇몇 건설업체들은 과다한 인증비용과 품질경영시스템의 구축 및 유지관리 비용을 감당하기 어려워 인증을 반납하고 있는 실정이다. 그렇기 때문에 이 시점에서 건설업체들이 생각해보아야 할 문제는 더 이상의 수주 경쟁의 무기가 되지 못하고 투자의 비용만 증가하고 있는 ISO 품질경영시스템의 효과에 대한 평가가 필요하다. 이를 위해 ISO 품질경영시스템에 대한 성과측정과 관련한 연구룰 통해 품질경영시스템의 성과측정을 위한 지표를 제시하고자 한다.

• 한국항공우주학회지
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• 제42권6호
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• pp.453-460
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• 2014

본 논문에서는 위성항법시스템의 무결성 저해 요인 중, 항법메시지에 담겨 전송되는 궤도력 (Ephemeris) 정보의 고장 여부를 판단할 수 있는 알고리즘을 분석 및 성능 평가를 수행하였다. 알고리즘은 반송파 측정값과 두 지상 기준국간의 기저벡터 정보가 활용된다. 주요 특징으로 기준국 기저선과 위성이 이루는 기하학적 조건 기저선 길이에 따라 동일 궤도력 고장에 대해 알고리즘의 성능의 편차가 발생할 수 있음을 확인하였다. 또한 알고리즘 적용이 적합한 GBAS의 지상 기준국 안테나 배치 방안 및 제주국제공항에 운용되었을 때의 한계치 및 성능 지표 (MDE : Minimum Detectable Error)를 계산하였다.