• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.87.1-87.1
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• 2011

The residential Fuel Cell system has high efficiency of 85% with transferring natural gas to electrical power and heat, directly and it is a friendly environmental new technology in that $CO_2$ emission can reduce 40% compared with conventional power generator and boiler. The residential fuel cell system consists of two main parts which have electrical and hot storage units. The electrical unit contains a fuel processor, a stack, an inverter, a control unit and balance of plant(BOP), and the cogeneration unit has heat exchanger, hot water tank, and auxiliaries. 5kW class fuel process was developed and tested from 2009, it was evaluated for long-term durability and reliability test including with improvement in optimal operation logic. Stack development was crried out through improvement of design and evaluation protocol. Development of system controller was successfully accomplished through strenuous efforts and original control logic was optimized in 5kW class PEMFC system. In addition, we have been focused on development of system process and assembly technology, which bring about excellent improvement of reliability of system. The 5kW class PEMFC system was operated under dynamic conditions for 1,000 hours and it showed a good performance of total efficiency and durability.

• 한국군사과학기술학회지
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• 제18권6호
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• pp.721-727
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• 2015

The improvement of the reliability of weapon systems and the reduction of the total life-cycle cost based on the improving of the DT&E system for Company Organized weapon systems research and development are urgently required. The major advanced countries operate test and evaluation centers for military (U.S.), manage a large scale organization of IPT personnel (England) or conduct management of DT&E through a third party organization (France). Based on a survey of experts, an improvement of the DT&E policy in terms of reliability and objectiveness is needed, and management through a third party national defense agency and civilian agency such as the Surion development case is required. In addition, although it appears that efficiency improves when management of DT&E is performed by national defence agencies rather than civilian agencies, it is necessary to proceed by selecting a civilian agency based on competition in the case that it is difficult to select a national defence agency.

• 대한안전경영과학회지
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• 제7권4호
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• pp.141-163
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• 2005

The international SPICE (Software Process Improvement and Capability determination) Project ISO/IEC 15504(SPICE : Software Process Improvement and Capability determination) is an emerging International Standard on SPA(Software Process Assessment). A prime motivation for developing this standard has been the perceived need for an internationally recognized software process assessment framework that pulls together the existing public and proprietary models and methods. A SPICE assessment can be considered as one of representative SPA model since assessors assign ratings to indicators and metrics to measure the capability of software process. But this models doesn't provide a systematic measurement procedures and dynamic method for SPI(Software Process Improvement). Through the evaluation of SPICE is capable of providing a substantiated basis for using the notion of capability, as well as providing information for nacessary improvements to the standard using 6sigma process. As a result, this paper propose a measurement procedure and guidelines for application of 6sigma process to guarantee the reliability in SPI and suggest the structure to support SPI on overall organization.

• 전기학회논문지
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• 제64권3호
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• pp.485-491
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• 2015

This paper shows the design improvement and test model of FAU (Frequency Analysis Unit) in PDD (Partial Discharge Diagnosis system) for 800kV GIS (Gas Insulated Switchgear). We found some problems during operation of previous FAU, such as the aging of fiber-optic converter that can cause communication error, the malfunction of signal analysis circuit etc. And then we solved those problems by design improvement and verified the performance through type test. To monitor partial discharge, the performance of UHF sensor is important but the performance of frequency analysis unit is also very important. So we solved communication error, the malfunction of signal analysis circuit and then increased the operation reliability of FAU by improving fiber-optic converter and signal analysis circuit. Accredited testing laboratory carried out the performance verification test according to performance test criteria and procedure of reliability test standards, IEC-60225, 61000 and 60068 etc. We confirmed the test results which correspond with the performance test criteria.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.542-545
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• 2006

RFID는 각종 서비스 산업은 물론 물류, 산업 현장, 제조 공장과 물품의 흐름이 있는 곳이면 어디에서나 적용이 가능하여 사회 여러 분야로부터 큰 관심을 받고 있다. 하지만 현재 900MHz 대역의 RFID에서 사용하는 ISO18000-6의 프로토콜에서는 에러검출을 위한 CRC16만을 사용하고 있으며, 에러정정능력을 갖추지 못해 그 신뢰성이 매우 떨어진다. 본 연구에서는 이러한 RFID 시스템의 신뢰성 향상을 위하여 Reader에서 Tag로의 데이터 전송 시에 대역확산방식과 컨볼루션 부호를 적용하여 시스템의 신뢰성 향상을 목적으로 하고 있으며, 또한, 이러한 방식을 적용했을 때와 적용하지 않았을 때의 에러율을 측정 비교하였다.

• International Journal of Internet, Broadcasting and Communication
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• 제15권3호
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• pp.191-202
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• 2023

This study aims to propose a framework for evaluating the impact of artificial intelligence (AI) services, based on the concept of AI service impact. It also suggests a model for evaluating this impact and identifies relevant factors and measurement approaches for each item of the model. The study classifies the impact of AI services into five categories: ethics, safety and reliability, compliance, user rights, and environmental friendliness. It discusses these five categories from a broad perspective and provides 21 detailed factors for evaluating each category. In terms of ethics, the study introduces three additional factors-accessibility, openness, and fairness-to the ten items initially developed by KISDI. In the safety and reliability category, the study excludes factors such as dependability, policy, compliance, and awareness improvement as they can be better addressed from a technical perspective. The compliance category includes factors such as human rights protection, privacy protection, non-infringement, publicness, accountability, safety, transparency, policy compliance, and explainability.For the user rights category, the study excludes factors such as publicness, data management, policy compliance, awareness improvement, recoverability, openness, and accuracy. The environmental friendliness category encompasses diversity, publicness, dependability, transparency, awareness improvement, recoverability, and openness.This study lays the foundation for further related research and contributes to the establishment of relevant policies by establishing a model for evaluating the impact of AI services. Future research is required to assess the validity of the developed indicators and provide specific evaluation items for practical use, based on expert evaluations.

• 한국ITS학회 논문지
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• 제11권5호
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• pp.78-88
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• 2012

도로상에 설치되어 있는 AVI는 두 가지 목적으로 (1) 방범용, (2) 교통용으로 구분되며, 관리기관 또한 (1) 경찰청, (2) 지자체, (3) 지방국토관리청, (4) 한국도로공사로 다양하다. 하지만 수집데이터는 차량번호, 통행시간, 차량사진으로 동일함에도 불구하고 구축된 목적에 따라서만 데이터가 이용되고 있어 관리주체가 상이하기 때문에 데이터간의 연계가 어려운 실정이다. 따라서 본 연구는 이 데이터를 통합하여 교통정보 생성용으로 활용가능성을 평가하고, 센터속도의 신뢰성 제고를 목적으로 방범-교통 AVI DB를 연계 통합한 구간검지체계의 도입방안을 제시하는 것을 목적으로 한다. 향후 교통용과 방범용의 AVI의 DB를 통합하여 교통정보 생성용으로 활용할 경우 구간소통정보를 산출할 수 있는 구간이 확대되고, 센터속도와 실측값 사이의 오차율을 감소시키는 방안으로 활용될 수 있을 것으로 판단되며, 방범 측면에서도 범죄 예방률 및 검거율이 향상될 것으로 기대된다.

• 동력기계공학회지
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• 제14권2호
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• pp.60-64
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• 2010

This paper introduces reliability improvement and time saving in eddy current inspection by signal characteristic optimization of multi-coil eddy current array probe. In the past, Multi-coil array probe and single probe were used for the gas turbine rotor surface inspection & defect evaluation. The multi-coil array probe was used for the broad area inspection. But the signal deviations among multi-coil array probe are maximum 28% in commercial probe. This differences were considered to impedance differences among coils, so it is very difficult to evaluate exact defect size. The signal deviations among multi-coil array probe are maximum 28% in commercial probe. So, single coil inspection was used for exact defect sizing. The purpose of this study is to improve signal deviations of multi-coil array probe. The introduced new technology can improves this deviation by adjusting input voltage in each coil. At first, apply same voltage in each coil and collect signal amplitude of each coil. And calculate new input voltage based on signal amplitude of each coil. If the signal amplitude deviation is within 5% among multi-coil array probe, the signal amplitude of multi-coil array probe is reliable. The proposed technology gives 2% signal deviation among multi-coil array probe. The proposed new technology gives reliability improvement and inspection time saving in eddy current inspection.

• 한국컴퓨터정보학회논문지
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• 제17권4호
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• pp.173-184
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• 2012

정보시스템 감리의 의무화와 감리수요의 증가에 따라 정보시스템 감리의 품질 향상이 중요시되고 있으나, 현행 정보시스템 감리는 감리원의 경험 및 기술력, 그리고 주관적인 판단에 의존하는 바가 크며, 감리 이해 관계자로부터 감리결과에 대한 객관성및 신뢰성에 대한 불신감을 초래하고 있다. 더구나 지금까지 감리 객관성 및 신뢰성 확보를 위한 관련 연구 활동은 매우 미흡한 실정이다. 이에 본 논문에서는 정보시스템 감리평가를 위한 정량화 방법을 제시함으로써 정보시스템 감리의 준거성 객관성 신뢰성의 확보 및 향상을 통하여 전반적으로 감리의 품질향상에 기여하고자 한다. 본 논문에서 제시한 정량화 방법은 크게 평가영역 및 평가항목, 평가항목 점수산정의 2가지 영역으로 구성되어 있으며, 정보시스템 감리기준을 범용적으로 정보시스템 감리평가에 적용할 수 있는 정량평가 방법이다.

• 한국안전학회지
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• 제31권5호
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• pp.95-101
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• 2016

This study proposes a multi-scale dynamic system reliability analysis of control system as a method of quantitative evaluation of its performance in probabilistic terms. In this second paper, we discuss the control effect of the viscous damper on the seismic performance of the structure-level failure. Since the failure of one structural member does not necessarily cause the collapse of the structural system, we need to consider a set of failure scenarios of the structural system and compute the sum of the failure probabilities of the failure scenarios where the statistical dependence between the failure scenarios should be taken into account. Therefore, this computation requires additional system reliability analysis. As a result, the proposed approach takes a hierarchial framework where the failure probability of a structural member is computed using a lower-scale system reliability with the union set of time-sequential member failures and their statistical dependence, and the failure probability of the structural system is again computed using a higher-scale system reliability with the member failure probabilities obtained by the lower-scale system reliability and their statistical dependence. Numerical results demonstrate that the proposed approach can provide an accurate and stable reliability assessment of the control performance of the viscous damper system on the system failure. Also, the parametric study of damper capacity on the seismic performance has been performed to demonstrate the applicability of the proposed approach through the probabilistic assessment of the seismic performance improvement of the damper system.