• Title/Summary/Keyword: Deadlocks

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A New Deadlock Detection Mechanism in Wormhole Networks (웜홀 네트웍을 위한 새로운 교착상태 발견 기법)

  • Lee, Su-Jung
    • Journal of KIISE:Computer Systems and Theory
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    • v.30 no.5_6
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    • pp.280-289
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    • 2003
  • Deadlock recovery-based routing algorithms in wormhole networks have gained attraction due to low hardware complexity and high routing adaptability Progressive deadlock recovery techniques require a few dedicated resources to transmit deadlocked packets rather than killing them. Selection of deadlocked packets is primarily based on time-out value which should be carefully determined considering various traffic patterns or packet length. By its nature, current techniques using time-out accompany unignorable number of false deadlock detections especially in a heavy-loaded network or with long packet size. Moreover, when a deadlock occurs, more than one packet may be marked as deadlocked, which saturate the resources allocated for recovery. This paper proposes more accurate deadlock detection scheme which does not make use of time-out to declare deadlock. The proposed scheme reduces the probability to detect false deadlocks considerably. Furthermore, a single message is selected as deadlocked for each cycle of blocked messages, thereby eliminating recovery overheads.

A Study on the Drift of Cybersecurity Law by Element Analysis of Political Gridlock (입법교착 요소로 분석한 사이버안보법 표류에 관한 연구)

  • Bang, Hyu;Kwon, Hun-Yeong
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.31 no.4
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    • pp.801-816
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    • 2021
  • This study analyzes the political and legislative progress that although basic acts to establish an integrated system of cybersecurity are steadily being proposed, they have not been passed as legislative deadlocks under the two major parties. It shall be analyzed through Korea's legislative system, including differences in contents and interests of the disposal act, the timing and cycle of election ect. The study analyzes why the basic cybersecurity law was previously scrapped and faced political gridlock situation by analyzing the differences in the contents and interests of the two major parties, and the timing and cycle of the proposed legislation.

Algorithm for Deadlock Prevention of Generalized Philosophers' Dining Problem (일반화된 철학자 만찬 문제의 교착상태 예방 알고리즘)

  • Sang-Un Lee
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.23 no.2
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    • pp.73-78
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    • 2023
  • The dining philosophers problem(DPP) is that five philosophers sit around a round table and eat spaghetti(or noodles) together, where they must have a pair of chopsticks(two) on both sides of them to eat, and if all philosophers have one chopstick on the right, no one can eat because the deadlock occurs. Deadlocks are a problem that frequently occur in parallel systems, and most current operating systems(OS) cannot prevent it. This paper proposes a silver bullet that causes no deadlock in an OS where all processors of 2≤n≤∞ have multiple parallel processing capabilities. The proposed method is a group round-robin method in which ⌊n/2⌋ odd processors form a group and perform simultaneously, and shift right to the next processor when execution ends. The proposed method is to perform two times for even processors, three times for odd processors per one round-robin. If the proposed method is performed n times, even-numbered processors perform n/2 times and odd-numbered processors perform (n-1)/2-times.

A Historical Review Since 1988 on the Relationship Between National Assembly, President and Political Parties (민주화 이후 국회-대통령-정당의 상생관계? : 역사적 관점에서)

  • Cho, Jung-Kwan
    • Korean Journal of Legislative Studies
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    • v.15 no.1
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    • pp.5-38
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    • 2009
  • This study analyzes the relationship since 1988 between National Assembly, president and political parties in Korea, and to find critical conditions for developing a mutually beneficial relationship among them. It argues that the levels of both internal power concentration and cohesiveness(or discipline) of political parties matter greatly, and applies them as theoretical framework for the historical review. By 2002, major political parties were highly concentrated in power and their discipline was strong. Consequently parties fought collectively with each other and Assemblies repeatedly saw standoffs and deadlocks. Reforms of 2002-04 that sought higher degree of party democracy and more autonomy among members of National Assembly have not been able to bring in a productive legislative-president relationship. A cohesive faction politics under the leadership of (potential) presidential candidates keeps it from growing. This study suggests further democratization of party power and more autonomy to individual Assembly members.

A study on efficient operation method of handling equipments in automated container terminals (자동화 컨테이너터미널에서 운송장비의 효율적인 운영방안)

  • 이상완;최형림;박남규;박병주;권해경;유동호
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2002.11a
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    • pp.63-70
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    • 2002
  • The main subject to become a hub pen is automation The automated container terminal has already operated in advanced pons and it bas 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 moat optimal method of equipment operation in order to minimize loading time using each three types of effective AT 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 tine. 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).

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A Simulation Study on the Deadlock of a Rail-Based Container Transport System (레일기반 컨테이너 이송 시스템의 교착에 관한 시뮬레이션 연구)

  • Seo, Jeong-Hoon;Yi, Sang-Hyuk;Kim, Kap-Hwan
    • Journal of Navigation and Port Research
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    • v.42 no.1
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    • pp.47-56
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    • 2018
  • In this study, the focus is on the issue of whether a container terminal is facing the limitation of its productivity for serving mega-vessels with numerous containers. In order to enhance the terminal operations, a new conceptual design of the container handling system have been proposed. This research focuses on the rail-based container transport system and its operations. This system consists of rail-based shuttle cranes and rail-based transporters called flatcars. The deadlock problem for managing automated transporters in container terminals has been an important issue for a long measurement of time. Therefore, this study defines the deadlock situation and proposes its avoidance rules at the rail-based container transport system, which is required to handle numerous container throughput operations. The deadlock in the rail-based container transport system is classified into two parts: deadlock between cranes and flatcars; deadlock between flatcars. We developed the simulation model for use with characterizing and analyzing the rail-based container transport system. By running the simulation, we derived possible deadlock situations, and propose the several deadlock avoidance algorithms to provide results for these identified situations. In the simulation experiments, the performances of the deadlock avoidance algorithms are compared according to the frequency of deadlocks as noted in the simulations.