• Journal of Communications and Networks
• /
• 제9권1호
• /
• pp.93-104
• /
• 2007

Traffic grooming, in which low-rate circuits are multiplexed onto wavelengths, with the goal of minimizing the number of add-drop multiplexers (ADMs) and wavelengths has received much research attention from the optical networking community in recent years. While previous work has considered various traffic models and network architectures, protection requirements of the circuits have not been considered. In this paper, we consider survivable traffic grooming, or grooming traffic which contains a mix of circuits that need protection and that do not need protection. We assume a unidirectional ring network with all-to-all symmetric traffic with $t\geq1$ circuits between each node pair, of which s require protection. As it turns out, survivable traffic grooming presents a significant tradeoff between the number of wavelengths and the number of ADMs, which is almost non-existent in non-survivable traffic grooming for this type of traffic. We explore this tradeoff for some specific cases in this paper. We also present some new results and solution methods for solving certain non-survivable traffic grooming problems.

• 한국패류학회지
• /
• 제6권1호
• /
• pp.56-79
• /
• 1990

The present study on the classification and description of the marine archeogastropods based on the materials which were collected collected during the period from 12th to 17th of July in 1989 at nine localities of the Ullung Island. In addition to the 3fimilies and 8 species of the marine archeogastropods that have been reported, 7 familis and 29 species were reported including the 4 families and 21 unrecorede species from the Ullung Island as a result of this study. Among them, 3 species: Tugali decussata A. Adms 1852, Tuistichotuochus kima Shikawa & Habe 1965, Alcyna ocellata A. Adams, 1860 are found to be new to the fauna of Korea.

• 한국통신학회논문지
• /
• 제25권5B호
• /
• pp.956-965
• /
• 2000

본 논문에서는 파장 분할 다중화(Wavelength Division Multiplexing: WDM) 기법을 이용한 링 구조의 고속 광전송망에서 망 구성 비용의 주요 요소인 SONET ADM의 수를 줄이기 위한 효율적인 트래픽 그루밍 알고리즘을 제안하였다. 제안된 알고리즘은 송신지와 수신지간의 연결을 조합하여 최대의 완전 연결-링을 구성하는 연결-링 구성 알고리즘과 하나의 파장에 되도록 많은 노드를 수용할 수 있도록 그룹화하는 연결-링 그루밍 알고리즘으로 구성되었다. 이들 알고리즘은 불규칙하고 다양한 트래픽 및 망 상황을 고려하여 단방향과 양방향 링 모두에 적용될 수 있도록 하였으며, 연결-링 구성 단계에서는 절단 기법을 이용하여 공백을 최소활할 수 있도록 하였다. 또한 양방향 WDM 링에서는 트랙픽에 방향성이 존재하기 때문에 이를 고려한 방향 전환을 고려함으로써 w보다 효율적인 완전 연결-링 구성이 가능하였다. 제안된 알고리즘의 성능 평가를 위하여 다양한 망 상황 및 트래픽 요구사항에 대하여 시뮬레이션을 실시하였다. 시뮬레이션 결과 제안된 알고리즘이 다양한 트래픽 상황에서 기존의 알고리즘보다 SONET ADM 수를 줄일 수 있음을 보였다.

• 한국통신학회논문지
• /
• 제25권8A호
• /
• pp.1247-1253
• /
• 2000

SONET/ADM 망의 용량을 최대한 활용하기 위해선 트래픽 통합(grooming)이 필요하다 이는 저속의 여러 트랙픽들을 한 개의 고속 스트림으로 다중화하거나 그 반대로 함으로서 이루어진다 SONET 링 네트워크의 용량은 다중 파장상에서 운용됨으로서 증가될 수 있다 하더라도 이를 위해선 망 설계 시 많은 ADM을 사용하여 높은 비용이 들 수 있다 비용 측면에서 효과적인 설계를 위해선 제공되는 트래픽을 수용하면서 최대한 ADM개수를 줄이는 것이므로 본 논문에서는 WDM 링 네트워크를 위해 새롭게 제시된 다중 홉 트래픽 통합 방식의 특성과 성능을 소개하고 평가한다 다중 홉방식에서는 트래픽 행렬에서 요구되는 트래픽에 기반을 해석 각 노드에 ADM을 둔 다음 통합될 수 있는 파장들을 통합한다 그리고 노드들 중 하나를 각 파장 당 하나씩의 ADM을 가지는 허브노드로 선택한다 이렇게 함으러써 허브 노드는 모든 파장 사이에 존재하는 트래픽을 연결할 수 있다 알고리즘은 간단한 예를 통해서 설명되었다 본 논문의 결과에 의하면 통합 비율이 낮을 경우에는 단일 홉 접근 방식을 사용하는 것이 유리하지만 비율이 높고 노드수가 많을수록 제안한 다중 홉 방식이 좋은 성능을 보였다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권16호
• /
• pp.6863-6869
• /
• 2014

Objectives: Several preclinical and observational studies have shown that anti-diabetic medications (ADMs) may modify the risk of lung cancer. We performed a systematic review and meta-analysis evaluating the effect of metformin, sulfonylureas (SUs), thiazolidinediones (TZDs), and insulin on the risk of lung cancer in patients with diabetes mellitus (DM). Materials and Methods: We conducted a systematic search of Pubmed and Web of Science, up to August 20, 2013. We also searched the Conference Proceedings Citation Index (CPCI) and China National Knowledge Infrastructure (CNKI) for abstracts from major meetings. Fixed or random effect pooled measures were selected based on heterogeneity among studies, which was evaluated using Q test and the I2 of Higgins and Thompson. Meta-regression was used to explore the sources of between-study heterogeneity. Publication bias was analyzed by Begg's funnel plot and Egger's regression test. Associations were assessed by odds ratios (ORs) with 95% confidence intervals (CIs). Results: A total of 15 studies (11 cohort, 4 case-control) were included in this meta-analysis. In observational studies no significant association between metformin (n=11 studies; adjusted OR=0.99, 95%CI: 0.87-1.12), SUs (n=5 studies; adjusted OR=0.98, 95%CI: 0.79-1.22), or TZDs (n=7 studies; adjusted OR=0.92, 95%CI: 0.75-1.13), insulin (n=6 studies; adjusted OR=1.13, 95%CI: 0.79-1.62) use and risk of developing lung cancer was noted. There was considerable inherent heterogeneity between studies not explained by study design, setting, or location. Conclusions: Meta-analysis of existing studies does not support a protective or harmful association between ADMs use and risk of lung cancer in patients with DM. There was considerable heterogeneity across studies, and future, well-designed, prospective studies would be required for better understanding of any association.

• 한국경영과학회지
• /
• 제32권4호
• /
• pp.51-60
• /
• 2007

In this study, we consider the minimum ADM problem which is the fundamental problem for the cost-effective design of SONET ADM embedded in WDM ring networks. To minimize the number of SONET ADMs, efficient algorithms for the routing and wavelength assignment are needed. We propose a mathematical model based on the graph theory for the problem and propose a branch-and-price approach to solve the suggested model effectively within reasonable time. By exploiting the mathematical structure of ring networks, we developed polynomial time algorithms for column generation subroutine at branch-and-bound tree. In a computer simulation study, the suggested approach can find the optimal solution for sufficient size networks and shows better performance than the greedy heuristic method.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1997년도 추계학술대회 논문집
• /
• pp.694-697
• /
• 1997

As the life cycle of the vehicle become shorter, the method that reduce the development time of new model become more important. In this reason, the development of the simulator that provides similar environment with the actual vehicle load characteristics is increasing. In this paper, the link unit of the 3-axis road simulator is designed and simulated with dynamic analysis software ADMS. and the maximum stress and strain are analyzed for the safety of link and specifications of optimal design using finite element method.

• 한국정밀공학회지
• /
• 제13권10호
• /
• pp.30-35
• /
• 1996

Tires, bushings and stabilizers are the most difficult elements in vehicle modeling for dynamic analyses. Many studies were performed for tire modeling and the primitive data of bushing elements can be obtained from the suspension designer, but there are few things for stabilizer. This paper presents simulation results for the 3 kinds of stabilizer model with the multi-body dynamic analysis program ADAMS. Each simulation result was compared with the vehicle test result, and the stabilizer model was proposed to analyze the vehicle behaviors precisely.

• 소성∙가공
• /
• 제12권1호
• /
• pp.3-10
• /
• 2003

The formation of surface defects associated with Jotting in injection molding is related to the geometries of cavity and fate, operational conditions and the rheological properties of polymer. In this study we have examined jetting phenomena in injection molding process for the throe kinds of PCs which have different molecular weights and structures, PBT and PC/ABS alloy with several injection speeds. We have used various cavity shapes those are tensile, flexural and impact test specimens with various gates and cavity thicknesses. Through this study we have observed that the jetting is related to the dic swell of material. This means that the jotting is strongly affected by the elastic flow property rather than the viscous flow property in viscoelastic characteristics of molten polymer. Different resins have different elastic properties, and elastic flow behavior depends on the shear rate of flow, i.e. injection speed. Large die swell would eliminate jetting however, the retardation of die swell would stimulate jetting. In the point of mole design, reducing the thickness ratio of cavity to gate can reduce or eliminate jetting regardless of amount of elasticity of polymer melt.

• 정보처리학회논문지C
• /
• 제13C권2호
• /
• pp.167-170
• /
• 2006

파장 할당에 대해 제안된 알고리즘들의 대부분은 무한한 수의 ADM을 가정하여 I/O 블로킹을 배제하였으며 파장을 할당한 이후, 네트워크 내에 파장이 불연속적인 형태로 남게 되어 링크 블로킹을 증가시킬 수 있다는 문제점이 있다. 또한 최악의 경우 O(W $N^3$)의 시간 복잡도를 갖는다. 본 논문에서는 온라인 상에서 동적인 트래픽 요청에 대해 최악의 경우 O(W $N^2$)의 복잡도를 가지면서 I/O 블로킹과 링크 블로킹을 모두 고려하는 파장 할당 알고리즘을 제안하였다. 파장의 불연속성을 최소화함으로써 블로킹의 발생을 감소시킬 수 있었다.