• Journal of the Korea Society of Computer and Information
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• v.8 no.3
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• pp.26-33
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• 2003

The edge-chasing deadlock detection algorithm of Choudhary fails to remove the existing deadlocks after committing the transaction whose priority is lowest on the transaction wait-for path. We proposed a modified algorithm that solves this problem. In this thesis, the performance of the modified algorithm is compared with that of the Tsai's deadlock detection algorithm that uses transaction-resource graph(TR graph) using simulation approach.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.11
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• pp.2131-2136
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• 2016

Before Industry 4.0, a purpose of manufacturing processes is simply overcoming the weakness of product line. However, Industry 4.0 should determine its method of work of facilities' own accord. Manufacturing processes such as FMS, AMS, MAS have been developed in these procedures, but there are possibilities of deadlock that can be happened for the reason of machine, agent or resource sharing. There were many studies to solve this problem. However, studies about prevention of deadlock happened in the situation that manufacturing processes are reconfigured dinamically because of human's intervention are incomplete. This paper proposes the model of the situation reconfigured dinamically and the method to prevent the deadlock in this situation. The proposed method adjusts production and manufacturing time by broadcasting time error messages to machines around when the manufacturing time of machine intervened by human is changed. Through this, it is anticipated to prevent the deadlock if conditions of the product line are changed.

• Journal of the Korea Society for Simulation
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• v.18 no.1
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• pp.9-16
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• 2009

Since a deadlock is a condition in which the excessive demand for the resources being used by others causes activities to stop, it is very important to detect and prevent a deadlock. About the deadlock detection analysis methods are may divide like as Siphon, DAPN and transitive matrix, but it's very difficult to evaluate the performance. Since DES (Discrete Event Systems) is NP-hard, and these detection and avoidance methods used various factors in each technique, it's made difficult to compare with each other's. In this paper, we are benchmarked these deadlock detection analyze methods based on the complexity, the detection time and the understanding after approached to one example.

• Nuclear industry
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• v.38 no.5
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• pp.21-26
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• 2018

고준위 방사성폐기물 처분사업은 미 의회 내에서도 골치 아프고 민감한 문제로서 지난 몇 년간 아무 해결책 없이 손을 놓고 있는 상태이다. 교착 상태에 빠져 있는 이 문제는 올해 치러지는 선거가 끝난 후에나 해결책이 나올 수 있을 것으로 전망되고 있다.

• Annual Conference of KIPS
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• 2007.05a
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• pp.751-754
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• 2007

본 연구에서는 유연생산시스템에서의 교착상태 확인 및 회피 알고리즘을 추이적 행렬을 이용하여 제안한다. 추이적행렬은 플레이스와 플레이스간의 관계를 표현함으로 마킹의 흐름을 플레이스와 트랜지션간의 관계형에서 상태와 상태간의 관계를 표현함으로 상태의 변화 검증에 편리하다. 교착상태 확인 및 회피 알고리즘을 제시하고, 기존에 발표되어진 siphon과 DAPN알고리즘간의 비료 검토를 통하여 제안한 알고리즘의 유용성을 검증하였다.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1833-1834
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• 2008

본 논문에서는 다수의 AGV를 운용하는 물류자동화창고에서 최단경로가 배정된 AGV의 주행도중 발생하는 충돌 및 교착 상태를 예측하고 이를 회피하는 알고리즘을 개발하고자 한다. 충돌 및 교착 상태는 최단 경로와 경로 점유시간을 비교함으로써 예측하고 이를 경로 선입에 따른 우선권 및 지연시간에 따른 우선권에 따라 회피할 AGV를 선정함으로써 충돌 회피에 따른 AGV의 총 운행시간을 최소화한다.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.2
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• pp.49-54
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• 2005

This Paper Presents a non-blocking deadlock detection scheme with immediate cycle detection in multiprocessing systems. We assume an expedient state and a special case where each type of resource has one unit and each request is limited to one resource unit at a time. Unlike the previous deadlock detection schemes, this new method takes O(1) time for detecting a cycle and O(n+m) time for blocking or handling resource release where n and m are the number of processes and that of resources in the system. The deadlock detection latency is thus minimized and is constant regardless of n and m. However, in a multiprocessing system, the operating system can handle the blocking or release on-the-fly running on a separate processor, thus not interfering with user process execution. To some applications where deadlock is concerned, a predictable and zero-latency deadlock detection scheme could be very useful.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.3 s.303
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• pp.1-10
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• 2005

This paper proposes a novel fault-tolerant gait planning of a hexapod robot considering kinematic constraints. The failure concerned in this paper is a locked joint failure for which a joint in a leg cannot move and is locked in place. It is shown that the conventional fault-tolerant gait of a hexapod robot for forward walking on even terrain may be fallen into deadlock, depending on the configuration of the failed leg. For coping with such deadlock situation, a novel fault-tolerant gait planning is proposed. It can avoid deadlock by adjusting the position of the foot trajectory, and has the same leg sequence and stride length as those of the conventional fault-tolerant gait. To demonstrate the superiority of the proposed scheme, a case study is presented in which a hexapod robot, having walked over even terrain before a locked joint failure, could avoid deadlock and continue its walking by the proposed fault-tolerant gait planning.

• Proceedings of the Korea Society for Simulation Conference
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• 1996.05a
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• pp.10-14
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• 1996

본 논문은 토러스 망의 패킷 전송 효율을 평가하기 위해 각 노드가 에지당 2개의 입·출력 큐를 가지는 라우팅 알고리즘을 제시하고 시뮬레이션을 수행하여 그 결과를 분석하였다. 제시된 4가지 오름순차를 가지는 라우팅 알고리즘에 대해 시뮬레이션을 하기 위해 도착분포와 서비스분포는 지수분포를 갖도록하여 교착상태가 없는 패킷 전송 효율을 비교 평가하였다. 실험 결과로부터 무교착 상태로 패킷을 전달하기 위한 노드 큐의 크기를 알 수 있었고, 또한 입력 패킷 메시지의 분포에 따라 패킷의 전송 효율을 높이기 위한 버퍼의 크기를 예측할 수 있었다.

• Journal of the Korea Society for Simulation
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• v.19 no.4
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• pp.67-75
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• 2010

Deadlock usually appears in contain subsystem which is run in parallel and resources share modules. Siphons and traps have been well introduced to characterize deadlocks of Petri nets. Siphon concept be well used for proposing the detect and prevent deadlock by the pleasure researchers. But it's need many times and efforts to detect all siphon sub-nets in the Petri model. Since transitive matrix could explain all relations between the place and transitions in Petri nets, we propose an algorithm to detect all siphon sub-nets after analyzed the transitive matrix's properties. Examples are givens to illustrate the method.