• 한국신뢰성학회:학술대회논문집
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• 한국신뢰성학회 2000년도 추계학술대회
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• pp.405-409
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• 2000

The flow network is considered to be in a functioning state if it can transmit a maximum flow which is greater than or equal to a specified amount of flow. In this paper we consider the measures of importance of a link in the flow network. We define the structural importance and reliability importance of link when the required amount of flow is given. Also, we present the performance importance of link in a flow network. The performance importance can be used to determine which links should be improved first in order to make the greatest improvement in performance of the network. Numerical examples are presented for illustrative purpose.

• Communications for Statistical Applications and Methods
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• 제16권6호
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• pp.937-943
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• 2009

가변용량 네트워크에서의 각 링크는 서로 독립이며 용량한계가 설정되어 있다. 각 링크는 각동하거나 작동불능의 두 상태로 구별되며 작동불능 상태의 링크는 유량을 통과시킬 수 없다. 주어진 네트워크는 미리 설정된 기정용량이상의 최대 전송용량이 가능할 때 작동된다고 한다. 본 논문에서는 가변용량 네트워크에서 기정용량이 주어졌을 때의 각 링크의 용량에 관한 구조적 중요도와 신뢰성 중요도를 정의하고, 네트워크 성능지수에 관련한 링크 중요도 척도를 제시한다. 또한 다양한 구조의 네트워크에서의 수치예제를 통하여 제시된 척도를 비교분석한다.

• International Journal of Reliability and Applications
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• 제2권1호
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• pp.73-80
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• 2001

A network, where links have different capacities, is considered to be in functioning state if a specified amount of flow can be transmitted through the network. In this paper, we consider the measures of importance of a link in such networks. We define the structural importance and reliability importance of a link when the required amount of flow is given. We also present the performability importance, which can be used to determine which links should be improved first in order to make the greatest improvement in the expected maximum flow of network. Numerical examples are presented as well for illustrative purpose.

• 한국전자거래학회지
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• 제8권2호
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• pp.23-31
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• 2003

링크 기반 검색엔진은사용자의 질의어와 관련된 웹 문서들의 링크 정보를 이용하여 순위를 생성한다. 이러한 링크기반 웹 문서의 특성을 이용한 대표적인 순위 평가 알고리즘. HITS는 웹 페이지들 간의 상호 연결된 링크 정보로부터 웹 문서들의 중요도를 평가하고, 순위 정보에 따른 결과를 제시한다. 이러한 HITS 알고리즘의 문제점은 문서 내의 링크 빈도 수만을 고려하고, 입력 값으로 주어지는 웹 문서 집합의 특성에 의존적이라는 것이다. 본 논문에서는 링크기반 웹 검색 엔진들로부터 얻어진 문서 집합에 대해 질의와 검색결과 간의 적합도를 향상시킨 HITS 알고리즘을 수행하는 검색 에이전트를 설계하였다. 이로써 향상된 검객 성능과 결과의 지역성을 보완한다.

• 전력전자학회논문지
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• 제27권6호
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• pp.535-540
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• 2022

DC-link capacitors are reliability-critical components in a photovoltaic (PV) inverter. Typically, the lifetime of a DC-link capacitor is evaluated by considering the voltage and hot-spot temperature of the capacitor under the specific operating condition of the PV inverter. However, the output of the PV inverter is determined by solar irradiation and ambient temperature, which vary with the seasons; accordingly, the hot-spot temperature of the capacitor also changes. Therefore, the mission profile of the PV system should be considered to effectively evaluate the reliability of the DC-link capacitor. In this study, the reliability of the DC-link capacitor of a three-level NPC inverter is comparatively analyzed with and without considering the mission profiles of the PV system, where two mission profiles recorded in Arizona and Iza are considered. The accumulated damage of the DC-link capacitor is calculated based on the lifetime model by analyzing its thermal loading. Afterward, a reliability evaluation of the DC-link capacitor is performed at the component level and then at the system level by considering all capacitors by means of Monte Carlo analysis. Results reveal the importance of performing a mission-profile-based reliability evaluation during the design of high-reliability PV inverters to achieve the target reliability performance.

• 산업공학
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• 제16권spc호
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• pp.14-20
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• 2003

This paper presents a multi-criteria decision model and Multi-Criteria Generic Algorithm(MCGA) approach to improve backbone topology by leveraging the Virtual Link(VL) system in an hierarchical Link-State(LS) routing domain. Given that the sound backbone topology structure has a great impact on the overall routing performance in an hierarchical LS domain, the importance of this research is evident. The proposed decision model is to find an optimal configuration of VLs that properly meets two-pronged engineering goals in installing and maintaining VLs: i.e., operational costs and network reliability. The experiment results clearly indicates that it is essential to the effective operations of hierarchical LS routing domain to consider not only engineering aspects but also specific benefits from systematical layout of VLs, thereby presenting the validity of the decision model and MCGA.

• Journal of Mechanical Science and Technology
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• 제16권1호
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• pp.13-23
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• 2002

This paper presents inverse kinematic and dynamic analyses of HexaSlide type six degree-of-freedom parallel manipulators. The HexaSlide type parallel manipulators (HSM) can be characterized as an architecture with constant link lengths that are attached to moving sliders on the ground and to a mobile platform. In the inverse kinematic analyses, the slider and link motion (position, velocity, and acceleration) is computed given the desired mobile platform motion. Based on the inverse kinematic analysis, in order to compute the required actuator forces given the desired platform motion, inverse dynamic equations of motion of a parallel manipulator is derived by the Newton-Euler approach. In this derivation, the joint friction as well as all link inertia are included. Relative importance of the link inertia and joint frictions on the computed torque is investigated by computer simulations. It is expected that the inverse kinematic and dynamic equations can be used in the computed torque control and model-based adaptive control strategies.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제3B권4호
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• pp.195-201
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• 2003

In accordance with the computerization of railway signaling systems, the interface link between signaling equipment has been replaced by a digital communication channel and the importance of this communication link has become increasingly significant. However, there are some problems with the present state of railway signaling. First, different communication protocol is applied to interfaces between signaling although they have the same functions. Next, the communication protocols currently used in the railway fields contain various illogical components such as structure, byte formation, error correction scheme and so on. To solve these matters, a new data link protocol for railway signaling systems is designed. In this paper, the structure of protocol and the results of performance analyses are presented. It will be expected to increase the safety, reliability and efficiency of maintenance of signaling systems by using the designed communication protocol for railway signaling in Korea.

• 벤처창업연구
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• 제10권5호
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• pp.185-196
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• 2015

기존 산학협력의 연구에서, 산학협력의 연계(LINK)는 경로의존성에 의해 향후 지속적인 상호협력을 통해 다양한 채널의 폭을 가진다. 다양한 상호채널의 폭을 통해 산학협력의 연계(LINK)는 더욱 더 강력해지나, 반면 거래관련 장벽이 늘어나게 된다. 즉, 대학과 기업 간 링크(university-industry linkages) 관계를 다루는 문헌은 많이 검토되어져 왔지만, 상대적으로 이들 간에 존재하는 장벽과 그 장벽을 줄일 수 있는 요인에 대한 연구는 그리 많이 다뤄지고 있지 않다. 산학협력 정책의 중요성을 감안할 때, 산학협력의 장애물에 대한 연구의 부족은 효과적인 정책을 설계하는데 심각한 장애요인이 될 것이다. 본 논문은 산학협력의 상호채널의 폭과 산학협력의 장벽에 대해 기존의 문헌을 조사하고, 대학행정의 POB(Positive Organization Behavior)을 통해 산학협력의 장벽을 낮출 수 있는지를 분석해보고 이를 통해 정책점시사점을 제시해보고자 한다.

• IMMUNE NETWORK
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• 제12권2호
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• pp.41-47
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• 2012

Contemporary studies illustrate that peripheral injuries activate glial components of the peripheral and central cellular circuitry. The subsequent release of glial stressors or activating signals contributes to neuropathic pain and neuroinflammation. Recent studies document the importance of glia in the development and persistence of neuropathic pain and neuroinflammation as a connecting link, thereby focusing attention on the glial pathology as the general underlying factor in essentially all age-related neurodegenerative diseases. There is wide agreement that excessive glial activation is a key process in nervous system disorders involving the release of strong pro-inflammatory cytokines, which can trigger worsening of multiple disease states. This review will briefly discuss the recent findings that have shed light on the molecular and cellular mechanisms of glia as a connecting link between neuropathic pain and neuroinflammation.