• Journal of Communications and Networks
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• 제6권3호
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• pp.269-279
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• 2004

A new online multi-layer integrated routing (MLIR) scheme that combines IP (electrical) layer routing with WDM (optical) layer routing is investigated. It is a highly efficient and cost-effective routing scheme viable for the next generation integrated optical Internet. A new simplified weighted graph model for the integrated optical Internet consisted of optical routers with multi-granularity optical-electrical hybrid switching capability is firstly proposed. Then, based on the proposed graph model, we develop an online integrated routing scheme called differentiated weighted fair algorithm (DWFA) employing adaptive admission control (routing) strategies with the motivation of service/bandwidth differentiation, which can jointly solve multi-layer routing problem by simply applying the minimal weighted path computation algorithm. The major objective of DWFA is fourfold: 1) Quality of service (QoS) routing for traffic requests with various priorities; 2) blocking fairness for traffic requests with various bandwidth granularities; 3) adaptive routing according to the policy parameters from service provider; 4) lower computational complexity. Simulation results show that DWFA performs better than traditional overlay routing schemes such as optical-first-routing (OFR) and electrical-first-routing (EFR), in terms of traffic blocking ratio, traffic blocking fairness, average traffic logical hop counts, and global network resource utilization. It has been proved that the DWFA is a simple, comprehensive, and practical scheme of integrated routing in optical Internet for service providers.

• 정보보호학회논문지
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• 제15권2호
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• pp.81-94
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• 2005

최근 무선랜 환경을 우리 근체에 널리 퍼져있고 많은 사람들이 FDA를 비롯한 multimedia application들과 같은 휴대장치를 많이 사용함으로써 단말 장비들의 이동이 계속 늘어나고 있다 그러나 이러한 단말 장비들이 이동하여 현재 접속되어 있는 AP(Access Point)를 벗어나 다른 AP와 접속을 시도할 때 두 AP들 사이에는 핸드오프 지연이 발생한다. 이러한 핸드오프 지연을 줄이기 위해 이 논문에서는 효과적인 데이터 구조를 사용하는 WFH(Weighted Frequent Handoff)를 제안한다. WFH는 FHR(Frequent Handoff Region)에서 클라이언트의 이동확률 개념을 도입한 새로운 cache replacement algorithm을 사용하여 cache hit ratio를 높이고 토폴로지에서 불필요하게 중복되는 트래픽도 줄여준다. 이 알고리즘은 QoS를 기반으로 하는 클라이언트의 레벨과 이동 패턴에 따라서 인종되는 범위가 달라지는 FHR과 네트워크 이동 토폴로지를 동적을 캡처하는 neighbor graph을 이용하고 있다.

• 한국멀티미디어학회논문지
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• 제14권12호
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• pp.1559-1571
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• 2011

In wireless ad hoc networks, nodes communicate with each other using multihop routed transmission in which hop-by-hop cooperative diversity can be effectively employed. This paper proposes (i) two cooperation models for per-link cooperation (PLC) and per-node cooperation (PNC) for exploiting cooperative diversity in wireless ad hoc networks and (ii) a cooperative routing algorithm for the above models in which best relays are selected for cooperative transmission. First, two cooperation models for PLC and PNC are introduced and represented as an edge-weighted graph with effective link quality. Then, the proposed models are transformed into a simplified graph and a cooperative routing algorithm with O(n2) time is developed, where n is the number of nodes in the network. The effectiveness of the algorithm is confirmed for the two cooperation models using simulation.

• 한국컴퓨터정보학회논문지
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• 제21권7호
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• pp.47-52
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• 2016

This paper introduces an algorithm to construct an Eulerian cycle for Chinese postman problem. The Eulerian cycle is formed only when all vertices in the graph have an even degree. Among available algorithms to the Eulerian cycle problem, Edmonds-Johnson's stands out as the most efficient of its kind. This algorithm constructs a complete graph composed of shortest path between odd-degree vertices and derives the Eulerian cycle through minimum-weight complete matching method, thus running in $O({\mid}V{\mid}^3)$. On the contrary, the algorithm proposed in this paper selects minimum weight edge from edges incidental to each vertex and derives the minimum spanning tree (MST) so as to finally obtain the shortest-path edge of odd-degree vertices. The algorithm not only runs in simple linear time complexity $O({\mid}V{\mid}log{\mid}V{\mid})$ but also obtains the optimal Eulerian cycle, as the implementation results on 4 different graphs concur.

• 국제초고층학회논문집
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• 제7권2호
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• pp.171-183
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• 2018

Turner and Penn (1) from UCL have proved that Visibility Graph Analysis (VGA) can be used as a more accurate method to predict the pedestrian distribution in building spaces. However, this methodology neglects certain elements that are of special influence on pedestrian distribution in buildings, especially the entrances and exits. Based on Space Syntax, this dissertation improves on the traditional method of Visibility Graph Analysis, using three shopping centers in Shenzhen as examples, attempts to explore a new parameter - "attenuation index of pedestrians at the entrances and exits" - using relevant data of the entrances and exits of the three cases, and combines it with traditional VGA analysis through weighted calculation, in order to provide more accurate predictions of pedestrian patterns in shopping centers.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.28.3-28
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• 2001

This paper proposes a new algorithm that detects and separates the occluding and occluded objects in a 2D image. An input image is represented by the attributed graph where a node corresponds to a surface and an arc connecting two nodes describes the adjacency of the nodes in the image. Each end of arc is weighted by relation value which tells the number of edges connected to the surface represented by the node in the opposite side of the arc. In attributed graph homogeneous nodes pertained to the same object always construct one of three special patterns which can be simply classified by comparison of relation values of the arcs. The experimental results have shown that the proposed algorithm efficiently separates the objects ...

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2004년도 춘계학술발표대회
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• pp.777-780
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• 2004

본 논문은 여러 개체의 생물체 궤적을 효과적으로 추적하기 위해 Hungarian Algorithm을 이용한다. 생물체 궤적 정보와 생물체의 좌표 정보로 Weighted bipartite graph를 구성한다. weight는 궤적 정보와 좌표 정보의 거리, 속도, 각도를 비교하여 계산한다. 구성된 graph를 Hungarian Algorithm로 계산하여 가장 효율적인 matching이 이루어지도록 한다. 실제 생물체를 관찰하고 얻어진 데이터를 이용하여 실험을 하고, 제안한 방법의 효율성을 검증한다.

• 대한전자공학회논문지
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• 제24권2호
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• pp.338-346
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• 1987

This paper describes a method for verifying whether a given geometrical layout correcdtly reflects the original logic level description. The logic description extracted from layout data was directly compadred with the original logic diagram generated at logic level design stage where the logic diagram is represented as a weighted multi-place graph. The comparison is based on graph isomorphism and error messages(error categories and locations)are invoked if any difference is found between the two logic descriptions. An efficient partitioning algorithm which consists of two steps, candidate selection and equal weight partitioning procedure, enables the entire verification process to occur in O(n log n) time.

• 전자공학회논문지C
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• 제36C권4호
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• pp.17-29
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• 1999

본 논문은 데이터 의존적인 CMOS 회로(예: DSP) 의 전력량을 감축하기 위한 상위 수준 합성 기법에 대한 연구이다. 상위수준 합성은 스케줄링, 자원 및 레지스터 할당의 세가지로 나우어서 수행한다. 스케줄링시의 저전력 설계의 목적은 자원할당 시 입력을 재 사용할 수 있는 가능성을 증가시키는 것이다. 스케줄링 후에 자원 및 레지스터 할당 문제는 가중차기 부가된 앙립 그래프로 표현하여 최소비용흐름 알고리즘을 수행함으로써 스위칭 동작횟수가 적은 해를 얻는다. 제안된 알고리즘은 저전력 레지스터 및 자원 할당 문제에 대하여 O({{{{ { n}^{3 } }}}}) (n은 그래프의 노드수) 시간에 최적해를 제공한다. 벤치마크 회로에 대한 실험 결과는 15%의 전력 감축 효과를 나타낸다.

• Journal of applied mathematics & informatics
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• 제9권2호
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• pp.607-620
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• 2002

In this paper, we consider the updating problems to reconstruct the biconnected-components and to reconstruct the weighted shortest path in response to the topology change of the network. We propose two distributed algorithms. The first algorithm solves the updating problem that reconstructs the biconnected-components after the several processors and links are added and deleted. Its bit complexity is O((n'+a+d)log n'), its message complexity is O(n'+a+d), the ideal time complexity is O(n'), and the space complexity is O(e long n+e' log n'). The second algorithm solves the updating problem that reconstructs the weighted shortest path. Its message complexity and ideal-time complexity are $O(u^2+a+n')$ respectively.