• Journal of KIISE:Computer Systems and Theory
• /
• v.27 no.6
• /
• pp.608-618
• /
• 2000

We consider the problem of placing resources in a distributed computing system so that certain performance requirements may be met while minimizing the number of required resource copies, irrespective of node or link failures. To meet the requirements for high performance and high availability, minimum number of resource copies should be placed in such a way that each node has at least two copies on the node or its neighbor nodes. This is called the fault-tolerant resource placement problem in this paper. The structure of a parallel or a distributed computing system is represented by a graph. The fault-tolerant placement problem is first transformed into the problem of finding the smallest fault-tolerant dominating set in a graph. The dominating set problem is known to be NP-complete. In this paper, searching for the smallest fault-tolerant dominating set is formulated as a state-space search problem, which is then solved optimally with the well-known A* algorithm. To speed up the search, we derive heuristic information by analyzing the properties of fault-tolerant dominating sets. Some experimental results on various regular and random graphs show that the search time can be reduced dramatically using the heuristic information.

• Journal of the Korean Society for Library and Information Science
• /
• v.41 no.1
• /
• pp.165-184
• /
• 2007

The purpose of this study is to compare the job satisfaction of school library employees with independent variables. and to discern the variables that cause the greatest impact on job satisfaction. The study's 254 questionaries were collected from December 1, 2006 to December 31, 2006 from 327 school library employees. In this study, it is proved that there are differences between the job satisfaction of school library employees and independent variables: gender, the level of school library, length of service. and employment style. Tips for the inherent roles of school library media center were Provided based on inadequacies and other findings revealed through this study.

• KLA journal
• /
• v.53 no.3
• /
• pp.24-27
• /
• 2012

채 10년도 안되는 기간동안 학교도서관은 천국과 지옥을 오가고 있다. 2002년부터 교육인적자원부(현 교육과학기술부) 주도로 시작된 '학교도서관활성화사업'을 통해 낡은 학교도서관 시설은 현대식으로 바뀌었으며, 교원으로서 사서교사는 1998년부터 지속적으로 현장에 배치되었고, 2007년 "학교도서관진흥법"이 제정되면서 나름 학교도서관에 대한 구체적인 법적 관심을 받았다. 먼지 쌓이는 교실 한 칸도 되지 않던 창고같던 학교도서관은 늘어난 장서와 PC를 포함한 다양한 IT 기기, 편안하게 책을 읽을 수 있는 교구 등을 갖추면서 나름 도서관답게 바뀌기 시작했던 시기이다. 학교도서관 운영의 주체성과 자율성을 가질 수 있는, 많지는 않더라도 교사라는 지위로 사서교사가 전국의 초 중등학교에 지속적으로 배치되던 시기이기도 하다. 도서관 관련 법에서 늘 구석에 있던 학교도서관은 "학교도서관진흥법" 및 시행령이라는 단독법안으로 제정되어 법리 상 관심을 받던 시기였다. 여기에 더해 책 읽기에 대한 관심이 커지면서 학교도서관을 중심으로 다양한 책읽기 프로그램 등이 운영되고 나름 학교도서관이 활성화되는 것 같았다. 하지만 화려하게 바뀐 학교도서관은 자격이 있는 인적자원 배치와 지속적인 장서의 공급 등을 통해 유지되기보다는 운영시간 연장 등 시설 자체의 운영에 초점이 맞춰지는 시기로 바뀌었다. 98.6%에 이르는 학교도서관 설치 대비 46% 밖에 되지 않는 인적자원의 배치 현황, 그나마 학교도서관에 배치된 인적자원의 14.7%만이 정규직 사서교사, 사서(직원)이라는 현실은 안정적이고 지속적인 인적자원 배치에 대한 기대를 더 이상 할 수 없는 어려운 시기로 바뀌었음을 보여준다. 단독법안으로 학교도서관의 진흥과 활성화에 기여할 것으로 기대했던 "학교도서관진흥법"은 학교도서관 관련 시설, 인적자원, 운영에 대한 분명하고 명확하지 않은 법조항 때문에 관점에 따라 다양한 해석을 할 수 있어 오히려 학교도서관의 발전을 저해한다는 일부의 비판도 받았다.

• Journal of the Korea Convergence Society
• /
• v.11 no.4
• /
• pp.11-16
• /
• 2020

As a plan for oil spill accidents, research to collect and analyze optimal equipment assignments is essential. However, studies that have diversified and analyzed the optimal equipment assignments for responding to oil spill accidents have not been preceded. In response to the need for analyzing optimal equipment assignments study, we devised a genetic algorithm for optimal equipment assignments. The designed genetic algorithm yielded 10,000 optimal equipment assignments. We clustered using the k-means algorithm. As a result, the two clusters of Yeosu, Daesan, and Ulsan, which are expected to be the largest spills, were clearly identified. We also projected 16-dimensional data in two dimensions via Sammon's mapping. The projected data were analyzed for distribution. We confirmed that results of the simulation were better than those of optimal equipment assignments included in the cluster.In the future, it will be possible to implement an approximate model with excellent performance based on this study.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2022.05a
• /
• pp.4-7
• /
• 2022

작업배치스케줄러는 다수의 사용자에게 클러스터 시스템의 계산 자원을 효과적으로 제공하는 유용한 시스템 소프트웨어이다. 한국과학기술정보연구원에서는 작업배치스케줄러인 PBS와 SLURM을 이용하여 슈퍼컴퓨터 5호기 메인시스템인 누리온과 뉴론을 각각 공동활용서비스하고 있다. 본 논문에서는 뉴론의 제한된 계산자원을 다수의 연구자들에게 효율적으로 서비스하기 위해 SLURM 작업배치스케줄러의 공유노드 정책을 적용하는 방안과 작업통계 분석 기법을 소개한다.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.19 no.1
• /
• pp.111-116
• /
• 2019

Recently, GPU expands application domains from graphic processing to various kinds of parallel workloads. However, current GPU systems focus on the maximization of each workload's parallelism through simplified control rather than considering various workload characteristics. This paper classifies the resource usage characteristics of GPU workloads into computing-bound, memory-bound, and dependency-latency-bound, and quantifies the fine-grained bottleneck for efficient workload allocation. For example, we identify the exact bottleneck resources such as single function unit, double function unit, or special function unit even for the same computing-bound workloads. Our analysis implies that workloads can be allocated together if fine-grained bottleneck resources are different even for the same computing-bound workloads, which can eventually contribute to efficient workload allocation in GPU.

• Journal of Digital Contents Society
• /
• v.18 no.7
• /
• pp.1411-1418
• /
• 2017

The batch job scheduler recognizes the computational resources configured in the cluster environment and plays a role of efficiently arranging the jobs in order. In order to efficiently use the limited available resources in the cluster, it is important to analyze and characterize the characteristics of user tasks. To do this, it is important to identify various scheduling algorithms and apply them to the system environment. Most scheduler software reflects the user's work environment, from job submission to termination, as well as the state of the inventory and system status of the entire managed object. It also stores various information related to task execution, such as job scripts, environment variables, libraries, wait for tasks, start and end times. In this paper, we analyze the execution log of the scheduler such as user 's success rate, execution time, and resource size through information related to job execution through batch scheduler. Based on this, it can be used as a basis to optimize the system by increasing the utilization rate of resources.

• Journal of KIISE:Information Networking
• /
• v.28 no.2
• /
• pp.196-206
• /
• 2001

네트워크의 보편화와 개인용 컴퓨터의 고급화를 통한 가용 자원의 확장은 분산 컴퓨팅환경에서 작업 부하 균형의 성능 향상을 기대할수 있게 되었다. 하지만 이를 현실화시키기 위해서 다음과 같은 제약 사항을 극복해야 한다. 첫째 네트워크 연결된 각각의 시스템은 이질적인 하드웨어와 운영체제로 구성되어있다. 둘째 네트웍 대역폭의 격심한 변화가 존재하며 상이한 시스템 성능 차이가 존재한다. 셋째 어플리케이션의 요구조건이 상이하다. 본 논문에서는 작업부하 균형에 이동 에이전트 패러다임을 적용하며 위의 문제점을 해결하기 위하여세가지의 사항을 추가한다. 1)이질적인 분산 컴퓨팅 환경에 어플리케이션을 동적으로이식하기 위하여 분산 객체 지향 미들웨어인 CORBA[1] 기반 MASIF[2]를 이용한다. 2)유휴 자원정보에 기반한 어플리케이션의 동적배치를 위하여 지원 감지 모니터링을 실행한다. 3) 다양한 어플리케이션의 요구 조건을 만족시키기 위하여 다양한 모니터링 알고리즘을 동적으로 로드하는 자바 객체, MonitorHandler를 제안한다. 제안한 프레임워크의 실효성을 검증하기 위하여 프로토타입 어플리케이션을 구현하였다. 실험 결과 유휴 자원을 고려한 동적 배치가 정적배치나 초기 정보에 의한 단 한번의 배치보다 각각 57% 와 26%의 성능 향상을 보였다. 제안하는 프레임워크는 작업부하 균형 어플리케이션의 개발을 용이하게 하며 범용성과 확장성을 제공한다.

• The KIPS Transactions:PartA
• /
• v.14A no.6
• /
• pp.357-362
• /
• 2007

In distributed systems like cluster systems, in order to get more performance improvement, the initial task placement system precisely estimates and correctly assigns the resource requirement by the process. The resource-based initial job placement scheme needs the prediction of resource usage of a task in order to fit it to the most suitable hosts. However, the wrong prediction of resource usage causes serious performance degradation in dynamic load balancing systems. Therefore, in this paper, to resolve the problem due to the wrong prediction, we propose a new load metric. By the new load metric, the resource-based initial job placement scheme can work without priori knowledge about the type of process. Simulation results show that the dynamic load balancing system using the proposed approach achieves shorter execution times than the conventional approaches.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.9 no.3
• /
• pp.75-79
• /
• 2009

The purposes of this study were to find out the factors affecting the continuous participation of volunteer activities for disaster relief and to provide implications for the efficient management of sustainable disaster relief volunteer activities. In order to achieve these purposes, we investigated how much individual characteristics, the volunteer attitude and motivation, and institutional characteristics, respectively, affect the duration of disaster relief volunteer activities. The research was carried out targeting 261 disaster relief volunteer workers, aged over 20, who affiliated to various volunteer centers. Data were collected by survey methodology from May 7th to May 27th, 2008. A frequency analysis and a multiple regression were utilized for analyzing data. The results of this study were as follows: the continuity of volunteer activities of the subjects are likely to be high when they are older, have a job, are highly motivated, are assigned properly to the placement and task. Based on the results of this study, some practical implications were suggested. First, since placement and task assignment managed by volunteer organizations are very important for the continuity of volunteer activities, those organizations should have developed diverse volunteer activity programs considering volunteers' characteristics and interest. Second, the managers of those organizations need to sufficiently consider the characteristics of volunteers such as age and job when dispatching volunteers in disaster areas. The managers should help their volunteers to immerse in their volunteer work. Finally, it is necessary to induce social concern and support in disaster relief volunteer activities in order to make volunteers especially with jobs be constantly active in disaster relief activities.