배선 밀집도를 완화하기 위한 개선된 광역배치 기법

오은경(Eun Kyung Oh),허성우(Sung Woo Hur) 한국정보과학회 2008 정보과학회 컴퓨팅의 실제 논문지 Vol.14 No.4

기존의 CDP(Congestion Driven Placement) 기법[1]은 배선 밀집도에 크게 기여하는 넷에 속한 모든 셀들을 옮길 때 가능한 방향을 모두 고려하기 때문에 CPU시간을 많이 소모한다. 본 논문에선 배선 밀집도를 완화하기 위한 빠른 배치 기법, 즉 ICDGP(Improved Congestion Driven Global Placement)라 불리는 개선된 기법을 제안한다. ICDGP는 밀집된 지역에 있는 넷에 속한 셀들의 이동목표 지점을 정하기 위해 force-directed 기법을 사용하며, 각 셀은 이동 목표 지점으로만 옮기는 것을 고려한다. ICDGP는 또한 셀을 하나씩 옮기는 것보다 다수의 셀을 동시에 같이 옮기는 것이 낫다고 판단되면 같이 옮긴다. 실험결과에 의하면 CDP보다 ICDGP가 배선 밀집도 면에서 좋은 배치를 생성한다. 특히 CPU 시간은 평균 36% 개선되었다. Since previous work CDP (Congestion Driven Placement)[1] considers all possible directions to move every cell in nets which contribute highly to routing congestion, it consumes CPU time a lot. In this paper, we propose a faster global placement technique, so called ICDGP (Improved Congestion Driven Global Placement) to relieve the routing congestion. ICDGP uses the force-directed method to determine the target locations of the cells in the nets in the congested spots, and considers only to move the target location for each cell. If moving multiple cells simultaneously is considered better than moving each cell one by one it moves multiple cells simultaneously. By experimental results, ICDGP produces less congested placement than CDP does. Particularly, the CPU time is reduced by 36% on average.

CASPER: Congestion Aware Selection of Path with Efficient Routing in Multimedia Networks

Obaidat, Mohammad S.,Dhurandher, Sanjay K.,Diwakar, Khushboo Korea Information Processing Society 2011 Journal of information processing systems Vol.7 No.2

In earlier days, most of the data carried on communication networks was textual data requiring limited bandwidth. With the rise of multimedia and network technologies, the bandwidth requirements of data have increased considerably. If a network link at any time is not able to meet the minimum bandwidth requirement of data, data transmission at that path becomes difficult, which leads to network congestion. This causes delay in data transmission and might also lead to packet drops in the network. The retransmission of these lost packets would aggravate the situation and jam the network. In this paper, we aim at providing a solution to the problem of network congestion in mobile ad hoc networks [1, 2] by designing a protocol that performs routing intelligently and minimizes the delay in data transmission. Our Objective is to move the traffic away from the shortest path obtained by a suitable shortest path calculation algorithm to a less congested path so as to minimize the number of packet drops during data transmission and to avoid unnecessary delay. For this we have proposed a protocol named as Congestion Aware Selection Of Path With Efficient Routing (CASPER). Here, a router runs the shortest path algorithm after pruning those links that violate a given set of constraints. The proposed protocol has been compared with two link state protocols namely, OSPF [3, 4] and OLSR [5, 6, 7, 8].The results achieved show that our protocol performs better in terms of network throughput and transmission delay in case of bulky data transmission.

CAMR: Congestion-Aware Multi-Path Routing Protocol for Wireless Mesh Networks

장서우,강석구,윤성국 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.1

The Wireless Mesh Network (WMN) is a multi-hop wireless network consisting of mesh routers and clients, where the mesh routers have minimal mobility and form the backbone. The WMN is primarily designed to access outer network to mesh clients through backhaul gateways. As traffic converges on the gateways, traffic hotspots are likely to form in the neighborhood of the gateways. In this paper, we propose Congestion Aware Multi-path Routing (CAMR) protocol to tackle this problem. Upon congestion, CAMR divides the clients under a mesh STA into two groups and returns a different path for each group. The CAMR protocol triggers multi-path routing in such a manner that the packet reordering problem is avoided. Through simulations, we show that CAMR improves the performance of the WMN in terms of throughput, delay and packet drop ratio.

CAMR: Congestion-Aware Multi-Path Routing Protocol for Wireless Mesh Networks

Seowoo Jang,Seok-Gu Kang,Sung-Guk Yoon 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.1

The Wireless Mesh Network (WMN) is a multi-hop wireless network consisting of mesh routers and clients, where the mesh routers have minimal mobility and form the backbone. The WMN is primarily designed to access outer network to mesh clients through backhaul gateways. As traffic converges on the gateways, traffic hotspots are likely to form in the neighborhood of the gateways. In this paper, we propose Congestion Aware Multi-path Routing (CAMR) protocol to tackle this problem. Upon congestion, CAMR divides the clients under a mesh STA into two groups and returns a different path for each group. The CAMR protocol triggers multi-path routing in such a manner that the packet reordering problem is avoided. Through simulations, we show that CAMR improves the performance of the WMN in terms of throughput, delay and packet drop ratio.

CAMR: Congestion-Aware Multi-Path Routing Protocol for Wireless Mesh Networks

Jang, Seowoo,Kang, Seok-Gu,Yoon, Sung-Guk The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.1

The Wireless Mesh Network (WMN) is a multi-hop wireless network consisting of mesh routers and clients, where the mesh routers have minimal mobility and form the backbone. The WMN is primarily designed to access outer network to mesh clients through backhaul gateways. As traffic converges on the gateways, traffic hotspots are likely to form in the neighborhood of the gateways. In this paper, we propose Congestion Aware Multi-path Routing (CAMR) protocol to tackle this problem. Upon congestion, CAMR divides the clients under a mesh STA into two groups and returns a different path for each group. The CAMR protocol triggers multi-path routing in such a manner that the packet reordering problem is avoided. Through simulations, we show that CAMR improves the performance of the WMN in terms of throughput, delay and packet drop ratio.

주요 항만 및 연안항로의 계절별 해상교통혼잡도 변화에 관한 연구

강원식,송태한,김영두,박영수 해양환경안전학회 2017 해양환경안전학회지 Vol.23 No.1

본 연구에서는 계절별 혼잡도 변화를 검토하기 위해 1년 동안의 주요 연안 통항로 및 항만 입출항로를 대상으로 계절별 기상특보가 발효되지 않은 1주일간의 GICOMS Data를 바탕으로 혼잡도 평가를 실시하였다. 그 결과 시간당 평균 혼잡도의 계절별 차이는 최대 약 11 %, 평균 약 3.5 %, 피크시간 혼잡도의 계절별 차이는 최대 약 82 %, 평균 약 30 %를 보이는 것으로 분석되었다. 향후 혼잡도 평가시에 이러한 계절별 혼잡도 변화를 감안하여야 하며, 특히 해상교통안전진단에서의 평가 시에는 이러한 계절별 차이가 존재하므로 혼잡여부에 대한 해상교통 안전대책 마련에 더욱 주의를 기울여야 할 것이다. In this study, a congestion assessment was conducted to verify seasonal differences in congestion for major coastal traffic routes and fairways in major ports with GICOMS Data for 7 days without issuing a special weather report. As a result, a maximum of 11 % and 82 % are shown, with an average of 3.5 % and a 30 % seasonal difference for hourly average congestion and peak time congestion. Therefore, seasonal differences for the target area should be taken into consideration to perform further congestion assessments, particularly for maritime traffic safety assessments, and keen attention should be given to setting up safety measures against congestion.

Congestion-assessment and Hybrid Routing Protocol for Vehicular Ad Hoc Network

Minh Le Van,MingChuan Yang,Qing Guo 보안공학연구지원센터 2013 International Journal of Future Generation Communi Vol.6 No.2

긴급 재해 발생 시 피난 지원을 위한 탈출 경로 탐색 알고리즘

황준수(Jun-Su Hwang),최영복(Young-Bok Choi) 한국콘텐츠학회 2016 한국콘텐츠학회논문지 Vol.16 No.9

본 논문에서는 긴급 재해 발생 시 피난 지원을 목적으로 하는 긴급피난지원시스템을 구축하기 위하여 실내에서 화재, 테러 등의 재해 발생 시 탈출 경로 탐색 알고리즘을 구현하였다. 긴급 상황이 발생하면 알고리즘은 가장 빨리 탈출할 수 있는 비상구로 탈출 경로를 안내해 준다. 알고리즘은 비상구나 비상구 이외의 지역의 인구 밀도와 연령별 가중치를 적용하여 탈출 경로를 계산한다. 본 시스템은 혼잡한 비상구를 우회하게 함으로써 비상구의 과중한 혼잡과 탈출 경로 상의 혼잡을 감소시키면서 재해 발생 지역을 우회하여 탈출 하도록 돕는다. The emergency evacuation support system supports evacuation assistance when an urgent disaster occurs. We have implemented evacuation route search algorithm to assist people’s escape when a disaster occurs such as fires or terrorism in the building. The algorithm will guide the escape route at the fastest emergency exit of each region at the emergency state. The algorithm calculates the escape route by applying the weighting factor of age groups and population density around the emergency exit and of other regions. So the system helps escape to bypass the crowded emergency exit and the disaster area, and reduces the congestion of emergency exit and overloading of evacuation route.

설계 초기 단계에서 전력/클록 네트워크를 고려한 라우팅 밀집도 예측 방법론

안병규,정정화,Ahn, Byung-Gyu,Chong, Jong-Wha 한국전기전자학회 2012 전기전자학회논문지 Vol.16 No.1

본 논문은 설계 흐름의 초기 단계에서 SoC의 라우팅 밀집도를 빠르고 정확하게 예측하는 방법론을 제안한다. 라우팅 과정에서 발생하는 과도한 밀집 현상은 라우팅 실패를 야기하고, 물리 설계를 처음부터 다시하게 되는 불필요한 시간을 소모하게 한다. 설계 초기단계에서 라우팅 밀집도를 정확하게 예측하는 것은 성공적인 물리 설계를 이끌어 내며, 전체 설계 시간에 소모되는 비용을 최소화시킨다. 제안된 방법은 블록 수준 플로어플랜 단계에서 블록 간/블록 내부 인터커넥트, 가상으로 합성된 파워/클록 네트워크를 사용해서 정교한 라우팅 밀집도를 예측한다. This paper proposes the methodology to estimate the routing congestion of modern IC quickly and accurately at the early stage of the design flow. The occurrence of over-congestion in the routing process causes routing failure which then takes unnecessary time to re-design the physical design from the beginning. The precise estimation of routing congestion at the early design stage leads to a successful physical design that minimizes over-congestion which in turn reduces the total design time cost. The proposed estimation method at the block-level floorplan stage measures accurate routing congestion by using the analyzed virtual interconnections of inter/intra blocks, synthesized virtual power/ground and clock networks.

Based on the Part of Routing Information Congestion Modeling Research with the Large-Scale Network

An Shuzhao,Wang Zhaohui 보안공학연구지원센터 2014 International Journal of Future Generation Communi Vol.7 No.2