• 한국산학기술학회논문지
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• 제20권2호
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• pp.329-335
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• 2019

본 연구에서는 특정 유도무기체계에 대한 신뢰도 성장 분석을 수행하였다. 개발단계에서의 시험을 통해 고장 모드와 원인을 식별하고 시험 중 발견된 고장을 분석하여 지속적인 관리 활동을 수행하고 있다. 해당 유도무기체계는 유도탄과 발사 체계로 구성되어 있으며, 각 장비의 시험 결과에 따라 신뢰도 성장 분석을 실시하였다. 유도탄의 경우에는 일회성 무기로 성공과 실패인 이산형 데이터로 시험 결과를 획득하였다. 발사체계의 경우에는 시험에서 지속해서 장비 운용을 하여 연속형 데이터로 시험 결과를 획득하였다. 각각의 시험 결과 형태로 신뢰도 성장 모델을 Standard Gompertz 모델과 Crow-Extended 모델을 적용하였다. 해당 모델을 사용하여 현재까지 수행한 시험 결과에 대한 신뢰도 성장 분석 결과를 확인하였다. 또한 미래에 수행될 시험 결과를 가정하여 신뢰도 성장 결과를 예측할 수 있었다. 본 연구는 해당 유도무기체계의 신뢰도 목표값을 달성하고 시험 횟수를 결정하는데 있어 유용하게 활용될 수 있을 것이다. 그리고 이후 계획된 시험을 확인하여 해당 유도무기체계에 대한 신뢰도 성장 관리를 지속적으로 추진할 예정이다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.139-150
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• 2010

최근 한국에서는 세계적인 녹색기술을 맞아 향후 차세대 교통 시스템으로서 튜브 트레인 시스템의 본격적인 연구가 진행되고 있다. 한국 철도기술연구원(KRRI, Korea Railroad Research Institute)에서 튜브 트레인 시스템의 건설을 위한 목적으로 연구가 진행되고 있다. 본 논문에서는 기초연구의 일환으로 축대칭하며 긴 형상의 수송체가 가지는 다양한 튜브(터널) 내부의 압력, 막힘비율, 운행속도를 파라미터로 선정하여 전산해석을 수행하였다. 세부사항으로는 동일 형상의 운송체가 동일 운행속도를 가지고 일반적 압력의 개활지(오픈 시스템, 개활지 운행)를 운행할 때와, 다양한 환경(튜브 내 압력, 막힘비율, 운행속도)의 튜브 내부를 운행할 때에 대하여 튜브 트레인의 공력특성 연구를 수행하였다. 이를 통하여 다양한 운행속도-막힘비율 별로 개활지와 동일 에너지 효율 나오는 튜브 내 압력(P-D 관계)을 계산하였고, 막힘비율 증가에 따른 튜브 내 감압 정도(P-${\beta}$ 관계), 다양한 막힘비율-튜브 내 압력 별로 운행속도에 따른 전체 항력 양상(D-V 관계)을 보여 주었다. 그리고 개활지 운행시와 튜브 내부 운행시의 에너지 효율(주행저항)을 비교하였고, 튜브 내부 운행 시 트레인이 갖는 효율과 관계되는 충격파 발생의 임계속도(critical V-B 관계) 및 한계속도(V-P 관계)를 얻을 수 있었다. 이러한 연구의 결과는 튜브 시스템 설계 및 건설에 꼭 필요한 것이며 가이드라인을 제시했다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.477-481
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• 2004

High Quality CD, OAT audio requires that large amount of data. Currently, multi channel preference has been rapidly propagated among latest users. The MPEG(Moving Picture Expert Group) is provides data compression technology of sound and image system. The MPEG standard provides multi channel and 5.1 sounds, using the same audio algorithm as MPEG-l. And MPEG-2 audio is forward and backward compatible. The MDCT (Modified Discrete Cosine Transform) is a linear orthogonal lapped transform based on the idea of TDAC(Time Domain Aliasing Cancellation). In this paper, we proposed the micro-program type vector processor architecture a benefit in MDCT/IMDCT of MPEG-II AAC. And it's reduced operating coefficient by overlapped area to bind. To compare original algorithm with optimized algorithm that cosine coefficient reduced $0.5\%$multiply operating $0.098\%$ and add operating 80.58\%$. Algorithm test is used C-language then we designed hardware architecture of micro-programmed method that applied to optimized algorithm. This processor is 20MHz operation 5V.

• 한국직업건강간호학회지
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• 제29권1호
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• pp.78-87
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• 2020

Purpose: The purpose of this study was to identify the relationship between nursing error experience, coping behavior and job stress in operating room. Methods: A descriptive research design was used in this study. The participants were 228 operating room nurses in G city who surveyed between October 25 and November 25, 2017 using self-report questionnaires. The data were analyzed using IBM SPSS/WIN 24.0/AMOS WIN 24.0 Program, which determined frequency, percentage, mean, standard deviation, Pearson correlation coefficient, and structural equation model. Results: There were significant positive correlations between six sub-categories of nursing errors and job stress. We found negative correlations between coping behavior and job stress. There was a mediating effect of active coping between knowledge of nursing error and job stress. We found passive coping between inspection & monitoring related error and job stress. Conclusion: Study findings suggest that adequate education and the improvement in hospital environment and system should be required to reduce the nurses' job stress related to the patients' safety in operating room.

• Journal of Power Electronics
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• 제7권2호
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• pp.146-158
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• 2007

A multi-pulse GTO based voltage source converter (VSC) topology together with a fundamental frequency switching mode of gate control is a mature technology being widely used in static synchronous compensators (STATCOMs). The present practice in utility/industry is to employ a high number of pulses in the STATCOM, preferably a 48-pulse along with matching components of magnetics for dynamic reactive power compensation, voltage regulation, etc. in electrical networks. With an increase in the pulse order, need of power electronic devices and inter-facing magnetic apparatus increases multi-fold to achieve a desired operating performance. In this paper, a competitive topology with a fewer number of devices and reduced magnetics is evolved to develop an 18-pulse, 2-level $\pm$ 100MVAR STATCOM in which a GTO-VSC device is operated at fundamental frequency switching gate control. The inter-facing magnetics topology is conceptualized in two stages and with this harmonics distortion in the network is minimized to permissible IEEE-519 standard limits. This compensator is modeled, designed and simulated by a SimPowerSystems tool box in MATLAB platform and is tested for voltage regulation and power factor correction in power systems. The operating characteristics corresponding to steady state and dynamic operating conditions show an acceptable performance.

• 대한디지털의료영상학회논문지
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• 제9권1호
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• pp.17-19
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• 2007

This study applies in case of operating an exam using by the contrast order or inputting an order of a contrast media the exam of Radiology Department. It is developed for helping decision making as regards a process of an exam from reading the creatinine value automatically linked with Laboratory Information System. It can be confirmed by real-time information; therefore, the creditability of the information is able to be improved. We will create the base for Patient Monitoring System with the data from the side effect of the creatinine value and allergies. Decision Support System minimize the inconvenience and the riskiness of the given contrast medium for CT tests. We would like to improve medical services by providing a standard circumstance where patients are able to run tests safely and comfortably.

• 한국전자거래학회지
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• 제8권1호
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• pp.141-154
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• 2003

SOAP is a protocol used for information exchange in distributed computing environment and SOAP defines mechanisms for message transferring between distributed system and remote procedure call/response process. This SOAP is able to be used independently on hardware platforms and operating systems and program languages because it uses only a text-based XML for protocol. Therefore ebXML that is a standard for E-Commerce adopts SOAP for message exchange. In this paper, we implement XML Hub System using SOAP and apply on the system e-Procurement. By this XML Hub System we can more easily exchange messages for B2B. Accordingly we can manage and integrate a lots of business partners.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.165_166
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• 2009

A HTS(High Temperature Superconductor) Cable is regarded as the most underground power to respond higher power density delivery system. This paper discussed electrical characteristic and standards of HTS Cable system. Various HTS cable characteristics are examined[3-5], ad compared with XLPE cable characteristics on possible distribution system environment. HTS cable is required to stabilize thermal condition for superconducting status, possible improper operating condition which affects quench, unbalanced, and harmonics impacts are discussed. HTS cable is customer designed cable which shall be implemented in special requirement of power system, the standard origination process requires to establish a series of methodology including design manufacturing, testing and installation.

• 조명전기설비학회논문지
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• 제26권8호
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• pp.42-49
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• 2012

Grid-connected photovoltaic generator system requires high performance PCS(Power Conditioning System) according to the standard of 'Distributed Generation Grid-Connected Technology Standards'. This paper presents the MPPT control method which improves output efficiency through fast tracking to the maximum power point of PV and a reduced self-excited vibration. Secondly, in this paper DVR function was applied to PCS to compensate the voltage sag frequently happening for a power system. The proposed PCS control is analyzed and compared to conventional PCS operating characteristic, the various insolation and loads, and voltage sag condition through PSIM tool. It proves the utility.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(II)
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• pp.259-264
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• 2003

Failure code system must include data of maintenance history, classification of failure, affective range and situation when failure occur. But the present failure code system have used a simple code system for classification to include only merchandise and tools. Advantageously, expansional standard code system that will be developed, it make that users can take steps of standardized overhaul and inspection as proposal maintain contents when failure occur or something wrong in vehicle of urban transit. Standardized failure codes must be developed and used that manufacturing companies and urban transit operating companies in order to give effect to maintenance works.