• 한국지능시스템학회논문지
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• 제16권2호
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• pp.191-197
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• 2006

본 논문에서는 원저 증기발생기 수위제어계통을 위한 고장검출 시스템을 설계한다. 이를 위하여 증기발생기 수위제어계통의 비선형 동적방정식을 미지의 매개변수를 갖는 T-S 퍼지시스템으로 모델링하고 좌 소인수 분해를 이용하여 오차발생기를 설계한다. 고장검출의 성능을 향상시키기 위하여 고장검출 필터의 설계법을 제안한다. 제시한 방법의 효용성을 컴퓨터 모의실험을 통하여 입증한다.

• 한국국방경영분석학회지
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• 제24권1호
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• pp.176-188
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• 1998

In this paper, it is identified that the optimal level of each performance measures (service and inventory level) is not sensitive to an uncertain environment under JIT Kanban system designed by Moeeni. Moreover, it is proposed that the optimal design method considering multiple performance characteristics is the optimal level decision method according to the relative importance differences of each performance when there exist multiple performance characteristics. The result from the simulation analysis shows that the number of Kanban for stage 3 (final process) and stage 2 is increased at the service level. It is found that the expected loss is minimal when the cycle time decreases and the container size increases. However, the stage 1 is not affected by the number and cycle time of Kanban. It is thus important to consider carefully the cycle time and the container size of the Kanban to satisfy the demand in right time. In case of inventory level, the working inventory level decreases when the container size is decreased and the working inventory level also decreases slightly when the cycle time of the Kankban is increased in stage 1 and 2.

• 정보보호학회논문지
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• 제28권6호
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• pp.1585-1594
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• 2018

데이터 주도 시대가 형성되면서 경제적 활용가치가 높은 정보의 수집과 분석, 생산과 유통에 관한 안전성 확보를 위한 정보보호 관리의 중요성이 날로 높아지고 있다. 이러한 환경에서 기업은 정보보호 관리체계(ISMS) 인증을 통해 정보보안에 대한 신뢰를 보장받고 있으나 관리체계를 구성하는 세부영역에 대한 수준 평가와 활용은 제한적이다. 이에 반해 보안 성숙도 모델은 기업의 정보보호 수준을 단계적으로 진단할 수 있고 시급히 개선해야 할 영역을 판단할 수 있음은 물론 기업의 특성과 수준에 맞는 목표 설정을 지원하는 도구가 된다. 본 논문에서는 성숙도 모델을 바탕으로 정보보호 분야에 특화되어 개발, 활용되고 있는 보안 성숙도 모델의 사례인 C2M2를 국내 ISMS인증과 비교, 분석하여 정보보호 관리 수준을 점검하기 위한 모형을 벤치마크 하고 ISMS인증의 정보보호대책 세부영역을 구성하는 점검항목 간 우선순위를 도출하여 단계적으로 정보보호 관리수준을 점검하고 구축을 지원할 수 있는 방법을 살펴본다.

• 산업경영시스템학회지
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• 제46권4호
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• pp.209-217
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• 2023

In this study, the evaluation items related to the effectiveness evaluation of the LVC (Live, Virtual, Constructive) training system of the Air Force were derived and the weights of each item were analyzed. The LVC training system evaluation items for AHP (Analytic Hierarchy Process) analysis were divided into three layers, and according to the level, 3 items were derived at level 1, 11 items at level 2, and 33 items at level 3. For weight analysis of evaluation items, an AHP-based pairwise comparison questionnaire was conducted for Air Force experts related to the LVC training system. As a result of the survey, related items such as (1) Achievement of education and training goals (53.8%), (1.2) Large-scale mission and operational performance (25.5%), and (1.2.1) Teamwork among training participants (19.4%) was highly rated. Also, it was confirmed that the weights of evaluation items were not different for each expert group, that is, the priority for importance was evaluated in the same order between the policy department and the working department. Through these analysis results, it will be possible to use them as evaluation criteria for new LVC-related projects of the Air Force and selection of introduction systems.

• 한국유체기계학회 논문집
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• 제20권1호
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• pp.5-14
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• 2017

A fan-motor assembly in a vacuum cleaner is analyzed through system-level analysis method. This system consisted of three components, a fan, motor, and the flow resistance of the motor, or of the vacuum cleaner. System-level analysis method is characterized by the combination of torque matching at a constant throttling condition between the fan and the motor and the pressure drop at a constant flow rate due to the flow resistance of the motor, or of the vacuum cleaner. The performance characteristics of the fan-motor assembly and the vacuum cleaner system could be predicted over the whole range of operation, based on the characteristics of each component. The predicted performance of the vacuum cleaner system through system-level analysis agreed well with the experimental results within 4.5% difference of pressure and 6% difference of the efficiency. The effect of flow resistance of a motor is investigated and it is found that the efficiency decrease of fan-motor assembly at the constant flow rate due to the flow resistance of a motor is determined by the flow resistance ratio(FRR), which is defined as a ratio of flow resistance of motor and the flow resistance of a constant throttling condition of a given point. The fan-motor assembly(S2 model) was modified to reduce the FRR from 9.0% to 2.4% and the experimental result shows that the efficiency of S2 model was improved by about 3% at best efficiency point.

• Reproductive and Developmental Biology
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• 제36권1호
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• pp.13-19
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• 2012

In order to provide the basis for developing practical mouse embryonic stem cells (mESCs) culture method, how the endogenous level of self-renewal-stimulating factor genes was altered in the mESCs by different extracellular signaling was investigated in this study. For different extracellular signaling, mESCs were cultured in 2 dimension (D), 3D and integrin-stimulating 3D culture system in the presence or absence of leukemia inhibitory factor (LIF) and transcriptional level of $Lif$, $Bmp4$ and $Wnt3a$ was evaluated in the mESCs cultured in each system. The expression of three genes was significantly increased in 3D system relative to 2D system under LIF-containing condition, while only $Wnt3a$ expression was increased by 3D culture under LIF-free condition. Stimulation of integrin signaling in mESCs within 3D system with exogenous LIF significantly up-regulated transcriptional level of $Bmp4$, but did not induce transcriptional regulation of $Lif$ and $Wnt3a$. In the absence of LIF inside 3D system, the expression of $Lif$ and $Bmp4$ was significantly increased by integrin signaling, while it significantly decreased $Wnt3a$ expression. Finally, the signal from exogenous LIF significantly caused increased expression of $Lif$ in 2D system, decreased expression of $Bmp4$ in both 2D and 3D system, and decreased expression of $Wnt3a$ in integrin-stimulating 3D system. From these results, we identified that endogenous expression level of self-renewal-stimulating factor genes in mESCs could be effectively regulated through artificial and proper manipulation of extracellular signaling. Moreover, synthetic 3D niche stimulating endogenous secretion of self-renewal-stimulating factors will be able to help develop growth factor-free maintenance system of mESCs.

• 한국대기환경학회지
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• 제9권3호
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• pp.207-215
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• 1993

In order to statistically predict $O_3$ levels in Seoul, the study used the TMS (telemeted air monitoring system) data from the Department of Environment, which have monitored at 20 sites in 1989 and 1990. Each data in each site was characterized by 6 major criteria pollutants ($SO_2, TSP, CO, NO_2, THC, and O_3$) and 2 meteorological parameters, such as wind speed and wind direction. To select proper variables and to determine each pollutant's behavior, univariate statistical analyses were extensively studied in the beginning, and then various applied statistical techniques like cluster analysis, regression analysis, and expert system have been intensively examined. For the initial study of high level $O_3$ prediction, the raw data set in each site was separated into 2 group based on 60 ppb $O_3$ level. A hierarchical cluster analysis was applied to classify the group based on 60 ppb $O_3$ into small calsses. Each class in each site has its own pattern. Next, multiple regression for each class was repeatedly applied to determine an $O_3$ prediction submodel and to determine outliers in each class based on a certain level of standardized redisual. Thus, a prediction submodel for each homogeneous class could be obtained. The study was extended to model $O_3$ prediction for both on-time basis and 1-hr after basis. Finally, an expect system was used to build a unified classification rule based on examples of the homogenous classes for all of sites. Thus, a concept of high level $O_3$ prediction model was developed for one of $O_3$ alert systems.

• 한국IT서비스학회지
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• 제2권2호
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• pp.75-85
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• 2003

The purpose of this study is to derive critical success factors for ERP system implementation by the level of total resource as an ability of human resource and the environment of information system in the small and medium manufacture.

• 한국철도학회논문집
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• 제8권2호
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• pp.170-175
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• 2005

This study presents a prediction of a failure rate in a safety required system that consists of a embedded control system, requiring a satisfaction of a quantitative safety requirement. International Standards are employed to achieve a regular procedures in the whole life cycle of a system, for the purpose of a prediction and a evaluation of a fault that might be able to be happened in a system. This International Standards uses SIL (Safety Integrity Level) to evaluate a safety level of a system. SIL is divided into 4 levels, from level 1 to level 4, and each level has functional failure rate and dangerous failure rate of a system. In this paper we describe the conventional method to predict the dangerous failure rate and propose a method using hazard analysis to predict the dangerous failure rate. The conventional method and the technique using hazard analysis to predict the dangerous failure rate are made a comparison through the control modules of the interlocking system in KTX. The proposed method verify better effectiveness for the prediction of the dangerous failure rate than that of the conventional method.

• 한국컴퓨터산업학회논문지
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• 제2권2호
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• pp.235-246
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• 2001

본 연구는 EDI의 이용수준(이용도 및 만족도)에 조직의 특성(기업의 규모 및 업무적합성)과 시스템의 운용수준(시스템의 성숙도 및 구성원의 참여도)이 영향을 미치는가를 분석하고자 하였다. 이를 위해 제조업과 금융업, 유통업, 서비스업에 종사하는 101개의 기업을 표본으로 선정하고, EDI 사용자에게 설문을 통해 수집된 자료를 회귀분석에 의해 검증하였다. 분석결과, 먼저 조직의 특성에 따른 영향에 있어서 기업의 규모는 EDI의 이용도 및 만족도에 영향을 미치지 않는 것으로 나타났다. 한편 업무의 적합성은 EDI의 이용도에 영향을 미치지 않으나, EDI의 만족도에는 영향을 미치는 것으로 나타났다. 둘째, 시스템의 운용수준이 EDI의 이용수준에 미치는 영향에 있어서 조직 구성원의 참여도는 EDI의 이용도와 만족도 모두에 영향을 미치는 것으로 나타난 반면, 시스템의 성숙도는 EDI의 만족도에만 영향을 미치는 것으로 나타났다. 이러한 분석결과는 EDI의 도입 및 활용의 효율성을 높일 수 있는 자료로 활용될 수 있을 것으로 기대된다.