• International Journal of Computer Science & Network Security
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• v.22 no.10
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• pp.230-236
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• 2022

Objectives: The primary goal of this article is to compare the multiple algorithms used for deadlock handling methods and then outline the common method in deadlock handling methods. Methods: The article methodology begins with introducing a literature review studying different algorithms used in deadlock detection and many algorithms for deadlocks prevented, recovered, and avoided. Discussion and analysis of the literature review were done to classify and compare the studied algorithms. Findings: The results showed that the deadlock detection method solves the deadlock. As soon as the real-time deadlock detection algorithm is identified and indicated, it performs better than the non-real-time deadlock detection algorithm. Our novelty the statistics that we get from the percentages of reviewing outcomes that show the most effective rate of 47% is in deadlock prevention. Then deadlock detection and recovery with 28% finally, a rate of 25% for deadlock avoidance.

• 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.

• Journal of Navigation and Port Research
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• v.29 no.8 s.104
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• pp.723-733
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• 2005

This paper presents a deadlock avoidance method for AGVs in automated container terminals. For a more efficient use of AGV traveling area, we divided the area into small-sized grids not enough to cover a whole AGV. Our deadlock avoidance method controls AGVs by identifying strongly connected components(SCCs) in a graph derived from the paths of AGVs on the grids. Also in this paper we suggest a route selection scheme which selects a route by predicting and comparing travel times of candidate routes by using a regression formula. Simulation experiments have shown that the proposed method can control AGVs for 48 hours without deadlocks and the count of AGV visits per QC is increased by $2\~10$ an hour.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2002.11a
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• pp.296-303
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• 2002

The main subject to become a hub port is automation. The automated container terminal has already operated in advanced ports and it has been planned for the basic planning and operation design in domestic case. The key of automated container terminal is effective operation of both ATC(automated transfer crane) and AGV(automated guided vehicle) which is automated handling equipments. This is essential to poductivity of automated container terminal. This study suggests the most optimal method of equipment operation in order to minimize loading time using each three types of effective ATC operation methods and AGV dispatching rules in automated container terminals. As the automated equipment operation causes unexpected deadlocks or interferences, it should be proceeded on event-based real time. Therefore we propose the most effective ATC operation methods and AGV dispatching rules in this paper. The various states occurred in real automated container terminals are simulated to evaluate these methods. This experiment will show the most robust automated equipment operation method on various parameters(the degree of yard re-marshaling, the number of containers and the number of AGVs)

• Journal of the Korea Society for Simulation
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• v.17 no.3
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• pp.75-83
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• 2008

A deadlock is a condition in which the excessive demand for the resources being used by others causes activities to stop and it is one of the important problems in process control system to detect and prevent deadlocks. While the reachability analyze methods or divide subnets for analyzing methods are well used, it requires a lot of times and effects to analyze the detection of the deadlock status. Furthermore, it could not be effective if the model is complex or huge. Therefore, it is necessary to develop a new and more efficient deadlock detection algorithm. In this paper, a deadlock detection conditions after analyzed the Petri Net using the transitive matrix has been proposed to solve these problems. For presenting the results, the suggested deadlock detection algorithm was also adapted to an illustrated FMS (Flexible Manufacturing System) model.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.11a
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• pp.296-303
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• 2002

The main subject to become a hub port is automation. The automated container terminal has already operated in advanced ports and it has been planned for the basic planning and operation design in domestic case. The key of automated container terminal is effective operation of both ATC(automated transfer crane) and AGV(automated guided vehicle) which is automated handling equipments. This is essential to productivity of automated container terminal. This study suggests the most optimal method of equipment operation in order to minimize loading time using each three types or effective ATC operation methods and AGV dispatching rules in automated container terminals. As the automated equipment operation causes unexpected deadlocks or interferences, it should be proceeded on event-based real time. Therefore we propose the most effective ATC operation methods and AGV dispatching rules in this paper. The various states occurred in real automated container terminals are simulated to evaluate these methods. This experiment will show the most robust automated equipment operation method on various parameters(the degree of yard re-marshaling, the number of containers and the number of AGVs)

• The Transactions of the Korea Information Processing Society
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• v.5 no.6
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• pp.1522-1536
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• 1998

In this paper, we present a modeling method for the real-time systems. This method is based on the DARTS (Design Approach for Real-Time Systems) and widely extended to analysis phase. The DARTS method provides a good guideline for the real -time software design, but it uses structured analysis and does not provide a specification language. So. this paper provides extended DARTS modeling techniques to the analysis area based on the objects. Internal behavior of system showed by means of a NPN (Numerical Petri Net) for analysis, and the specification language is provided based on the temporal logic for transition synchronization sequence control. By the example, we identified the proposed method was applied well. And through the reachability graph, we verified whether the deadlocks may occur or not in the analysis phase before the design phase. Thus. it gives easy way to analysis, so that it will lead to the design phase naturally.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.5
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• pp.749-756
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• 2011

Recently, ever-growing land price has caused public projects to come to considerable deadlocks. Up to date, project principals have relied upon mandatory expropriation policy or other relevant policies in order to procure land sites required for public projects in a short period, but these policies have brought about collective resistances and civil appeals from land owners and cause land compensation price to rise, resulting in delayed progress of public projects. Therefore, land banking system is enforced to resolve these issues. Successful implementation of land banking system requires purchase of sufficient land sites at affordable price so as to execute public projects and control real estate market. However, current version of Land Banking Act reveals several questions as contrary to public expectations in the days of its introduction. This study sought to make further analysis on the whole content of current legal system concerning land banking system. And based on the analysis, this study explored possible solutions for problems that hinder land banking system from its stable operations, so that this land banking system could contribute to resolving land problems by active promotion of public projects as originally intended and by the stabilization of land market based on balance control between supply and demand of land.

• Journal of the Korea Society for Simulation
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• v.15 no.1
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• pp.1-10
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• 2006

The Flexible Management System (FMS) consists of parallel and concurrent machines, pieces of equipment, and carrying systems classified as buffers, tools, and routers, respectively. The concurrent flow of multiple productions in a system is competed with one another for resources and this resulting competition can cause a deadlock in FMS. 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. Herein a new algorithm has been studied in order to detect and prevent deadlocks, after defining a relationship between the general places and resource share places in Petri nets like as DAPN: Deadlock Avoidance Petri Net. For presenting the results, the suggested algorithms were also adapted to the models that demonstrated FMS features.

• The Journal of the Korea Contents Association
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• v.8 no.2
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• pp.57-66
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• 2008

Most concurrency control protocols have been devised for resolving data conflicts among real-time transactions of a single type. Recent real-time database systems should support various types of real-time transactions due to needs of many different types of applications and steady improvement of hardware. In this paper, we propose integrated concurrency control protocol to resolve data conflicts among hard and soft real-time transactions. Our proposed protocol, based on PCP(Priority Ceiling Protocol) for a hard real-time transactions and MVPR(Multiversion with Precedence Relationship), guarantees that hard real-time transactions meet their deadline, and decreases the deadline miss ratio of soft real-time transactions. We also proved that the proposed protocol guarantees serializable schedules and no deadlocks. The performance of the proposed protocol has been compared with other real-time concurrency protocols.