• KSBB Journal
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• 제26권3호
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• pp.183-188
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• 2011

Adult stem cells, which have characteristic of self-renewal and multipotency, are specialized cell types, responsible for the tissue regeneration of the damaged tissue. Recent studies suggest that stem cells senescence (or stem cells' ageing) is closely associated with the variety of ageing-related phenotypes such as tissue atrophy, degenerative diseases and onset of cancers. During ageing, declining of stem cells function and subsequently occurring mal-differentiation of stem cells would be important to understand the biological process of development of ageing-related phenotypes such as tissue degenerations and cancers. This review focuses on the DNA damage stress as a cause of senescence of stem cells and their mal differentiation, which is closely link to defect of regeneration potentials and neoplastic transformation. Understanding of molecular mechanisms governingsuch events is likely to have important implications for developing novel avenues for balancing tissue homeostasis longer period of time, further leading to 'Healthy ageing'.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2007년도 학술대회
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• pp.336-340
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• 2007

This paper proposes a multicast scheme over IEEE 802.16 networks which support multiple upper layer protocols such as ATM, IPv4 packets, IPv6 packets, IEEE 802.3 over IPv4 and so on. The multicast capabilities over IEEE 802.16 are important both control plane and data plane. The proposed multicast scheme can be divided into two types: direct mapping and indirect mapping. The direct mapping scheme is that layer 3 address is directly mapped into CID information which is used for connection identifier at IEEE 802.16 link layer. The indirect mapping scheme has two steps for mapping between layer 3 address and layer 2 CID. Firstly, a layer 3 address translates to Ethernet MAC address with group MAC address. Secondly, a group MAC address is mapped into CID. The mapping scheme depends on the upper layer protocols.

• Journal of Power Electronics
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• 제16권4호
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• pp.1541-1550
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• 2016

This paper presents a theoretical analysis and comparisons of active power filter (APF) and hybrid power filter (HPF) systems, given terminal constraints of harmonic compensations in nonlinear loads. Despite numerous publications for the two types of filters, the features and differences between them have not been clearly explained. This paper presents a detailed analysis of the operations of a HPF inverter along with those of passive power filters (PPFs). It also includes their effects on the power factor at the grid. In addition, a theoretical analysis and a systematic comparison between the APF and HPF systems are addressed based on system parameters such as the source voltage, output power, reactive component size, and power factor at the grid terminals. The converter kVA ratings and dc-link voltage requirements for both topologies are considered in the presented comparisons

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Signal transduction in Toxicology
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• pp.144-144
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• 2001

Inappropriate up-regulation of cyclooxygenase-2 (COX-2) has been implicated for pathogenesis of various types of human cancer. COX-2 expression is known to be regulated by the eukaryotic transcription factor NF-$textsc{k}$B. In an attempt to link the NF-$textsc{k}$B activation and COX-2 induction, we have examined the kinetics of phorbol ester-induced activation of NF-$textsc{k}$B and COX-2 expression in the immortalized human breast epithelial cell line (MCF10A).(omitted)

• 한국항공운항학회지
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• 제26권2호
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• pp.39-46
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• 2018

Departure Manager (DMAN) is a tool to optimize the departure sequence and to suggest appropriate take-off time and off-block time of each departure aircraft to the air traffic controllers. To that end, Variable Taxi Time (VTT), which is time duration of the aircraft from the stand to the runway, should be estimated. In this paper, a study for development of VTT prediction algorithm based on machine learning techniques is presented. The factors affecting aircraft taxi speeds were identified through the analysis of historical traffic data on the airport surface. The prediction model suggested in this study consists of several sub-models that reflect different types of surface maneuvers based on the analysis result. The prediction performance of the proposed method was evaluated using the actual operational data.

• 한국경영과학회지
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• 제22권3호
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• pp.59-80
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• 1997

Designing highly survivable interoffice telecommunication networks is considered. The problem is formulated as a minimum-cost network design problem with three node connectivity constraints. These valid and facet-defining inequalities for the convex hull of the solution are presented. A branch and cut algorithm is proposed based on the inequalities to obtain the optimal solution. With the lower bound by the cutting plane algorithm, a delete-ink heuristic is proposed to otain a good upper bound in the branch and bound procedure. The effeciveness of the branch and cut algorithm is demonstrated with computational results for a variety of problem sets : different lower bounds, two types of link costs and large number of links. The cutting plane procedure based on the three inequalities provides excellent lower bounds to the optimal solutions.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1995년도 춘계공동학술대회논문집; 전남대학교; 28-29 Apr. 1995
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• pp.306-315
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• 1995

This paper presents a bin picking method using a slit beam laser in which a robot recognizes all of the unoccluded objects from the top of jumbled objects, and picks them up one by one. Once those unoccluded objects are removed, newly developed unoccluded objects underneath are recognized and the same process is continued until the bin gets empty. To recognize unoccluded objects, a new algorithm to link edges on slices which are generated by the orthogonally mounted laser on the xy table is proposed. The edges on slices are partitioned and classified using convex and concave function with a distance parameter. The edge types on the neighborhood slices are compared, then the hamming distances among identical kinds of edges are extracted as the features of fuzzy membership function. The sugeno fuzzy integration about features is used to determine linked edges. Finally, the pick-up sequence based on MaxMin theory is determined to cause minimal disturbance to the pile. This proposed method may provide a solution to the automation of part handling in manufacturing environments such as in punch press operation or part assembly.

• 한국철도학회논문집
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• 제10권2호
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• pp.103-111
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• 2007

The existing design materials by document type are restricted in searching and acquiring necessary design information because the materials consist of huge information and various document types. This study suggests a methodology to develop an electronic technical manual that can manage construction design materials by XML-base integrated information system. Electronic technical manual for design materials can provide visualized information through various multimedia tools such as multi-link, virtual reality and animation. Using an integrated electronic manual for construction project can prevent to miss necessary design information. The results of this study includes a data flow diagram to develop an interactive electronic technical manual (IETM) for construction design information. Finally the study suggests some scenarios for practical use and quantitative analysis of application effect analysis by AHP method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.825-829
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• 1993

As a part of the Department of Energy's Environmental Restoration and Waste Management Program, long-reach manipulators are being considered for the retrieval of waste from large storage tanks. Long-reach manipulators may have characteristics significantly different from those of typical industrial robots because of the flexibility of long links needed to cover the large workspace. To avoid structural vibrations during operation, control algorithms employing various types of shaping filters were investigated. A new approach that uses imbedded simulation was developed and compared with others. In the new approach, generation of joint trajectories considering link flexibility was also investigated.

• 한국인터넷방송통신학회논문지
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• 제9권6호
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• pp.117-123
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• 2009

본 논문에서는 일반적인 서바이벌특성을 2가지 형태로 분류하여 그 특정을 살펴보고, 네트워크에 이용 가능한 형태를 찾는다. 그리고 이중홈 방식을 이용하여 네트워크 형태에 따른 비용을 분석한다. 또한 서바이벌특성을 가능하게 해주는 네트워크의 물리구조를 최소비용으로 설계할 수 있는 휴리스틱알고리즘을 제안하고 그 결과를 분석하여 실제 네트워크설계에 쉽게 적용할 수 있음을 보인다.