• The Journal of the Korea Contents Association
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• v.8 no.2
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• pp.9-17
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• 2008

Tn this paper, we design and analyze an election algorithm, based on the Bully algorithm, in synchronous distributed systems. We show that the Bully algorithm, when using Failure Detector, is more effectively implemented than the classic Bully algorithm for synchronous distributed systems.

• The Transactions of the Korea Information Processing Society
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• v.6 no.1
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• pp.42-48
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• 1999

Consider the situation that informations necessary to solve a certain problem are distributed among processors on a network. It is called a distributed algorithm that in this situation each processor exchanges the message with adjacent processors to solve the problems. This paper proposes a distributed algorithm to solve the problem that constructs the weighted shortest path tree in an asynchronous network system. In general, a distributed algorithm is estimated by the number of messages(message complexity of the distributed algorithm proposed in this paper are O(n53) and O(nln) respectively. where n is the number of processors on the network.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.1
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• pp.20-29
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• 1990

In this paper, we propose the \ulcorner/G algorithm that is an efficient distributed process coordination algorithm. It controls mutually exclusive access to a shared resource in a distributed system. We show that the \ulcorner/G algorithm satisfies the properties of distributed systems. In performnace, the algorithm is more efficient than existing algorithms because it sends only 3(K-1)/G meassages.

• Smart Media Journal
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• v.10 no.4
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• pp.15-20
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• 2021

The distributed trigger counting problem is to notify the user when the total number of triggers received from a distributed system consisting of n nodes reaches a predefined value w. The distributed trigger counting problem is used for monitoring and global snapshots in various distributed systems. In this paper, we propose a simple and efficient algorithm for the distributed trigger counting problem. The proposed algorithm operates based on a tree structure of degree $\sqrt{n}$ and height 2. The proposed algorithm operates in three different phases based on the remaining number of triggers. Experimental results show that the proposed algorithm has a smaller message complexity than CoinRand, and MaxRcv also performed better when the number of nodes is not large.

• International Journal of Computer Science & Network Security
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• v.24 no.4
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• pp.192-196
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• 2024

The memory coherence problem occurs while mapping shared virtual memory in a loosely coupled multiprocessors setup. Memory is considered coherent if a read operation provides same data written in the last write operation. The problem is addressed in the literature using different algorithms. The big question is on the correctness of such a distributed algorithm. Formal verification is the principal term for a group of techniques that routinely use an analysis that is established on mathematical transformations to conclude the rightness of hardware or software behavior in divergence to dynamic verification techniques. This paper uses UPPAAL model checker to model the dynamic distributed algorithm for shared virtual memory given by K.Li and P.Hudak. We analyse the mechanism to keep the coherence of memory in every read and write operation by using a dynamic distributed algorithm. Our results show that the dynamic distributed algorithm for shared virtual memory partially fulfils its functional requirements.

• Journal of Navigation and Port Research
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• v.47 no.6
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• pp.401-409
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• 2023

This study compared and analyzed the performance of a distributed area search algorithm and a distributed probability search algorithm based on information exchange between ships. The distributed algorithm is a method that can search for an optimal avoidance route based on information exchange between ships. In the distributed area search algorithm, only a ship with the maximum cost reduction among neighboring ships has priority, so the next expected location can be changed. The distributed stochastic search algorithm allows a non-optimal value to be searched with a certain probability so that a new value can be searched. A circular-based ship collision avoidance model was used for the ship-to-ship collision avoidance experiment. The experimental method simulated the distributed area search algorithm and the distributed stochastic search algorithm while increasing the number of ships from 2 to 50 that were the same distance from the center of the circle. The calculation time required for each algorithm, sailing distance, and number of message exchanges were compared and analyzed. As a result of the experiment, the DSSA(Distributed Stochastic Search Algorithm) recorded a 25%calculation time, 88% navigation distance, and 84% of number of message exchange rate compared to DLSA.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.777-779
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• 1999

A new distributed/parallel algorithm simulator, DASim(Distributed Algorithm Simulator), is proposed in this paper. The idea is to ease the task of design, analysis and implementation of distributed algorithms. A small high level language has been proposed for the purpose. Through this non-language specific high level language, the users are spared from the tedious details about how to program distributed or parallel algorithms. Further, visualization of these algorithms are pretty helpful to understand behaviors of these algorithms.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.62 no.1
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• pp.36-44
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• 2013

This paper is written for the development and application of boiler fuel control algorithm and distributed control system of coal-fired power plant by the steps of design, coding, simulation test, site installation and site commissioning test. Fuel control algorithm has the upper algorithm and it is boiler master control algorithm that controls the fuel, feed water, air by generation output demand. Generation output demand by power load influences fuel control. Because fuel can not be supplied fast to the furnace of boiler, fuel control algorithm was designed adequately to control the steam temperature and to prevent the explosion of boiler. This control algorithms were coded to the control programs of distributed control systems which were developed domestically for the first time. Simulator for coal-fired power plant was used in the test step. After all of distributed control systems were connected to the simulator, the tests of the actual power plant were performed successfully. The reliability was obtained enough to be installed at the actual power plant and all of distributed control systems had been installed at power plant and all signals were connected mutually. Tests for reliability and safety of plant operation were completed successfully and power plant is being operated commercially. It is expected that the project result will contribute to the safe operation of domestic new and retrofit power plants, the self-reliance of coal-fired power plant control technique and overseas business for power plant.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.2
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• pp.287-295
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• 2010

In this paper, we introduce a novel approach to optimization algorithm which is a distributed Mean field Genetic algorithm (MGA) implemented in MPI(Message Passing Interface) environments. Distributed MGA is a hybrid algorithm of Mean Field Annealing(MFA) and Simulated annealing-like Genetic Algorithm(SGA). The proposed distributed MGA combines the benefit of rapid convergence property of MFA and the effective genetic operations of SGA. The proposed distributed MGA is applied to the channel routing problem, which is an important issue in the automatic layout design of VLSI circuits. Our experimental results show that the composition of heuristic methods improves the performance over GA alone in terms of mean execution time. It is also proved that the proposed distributed algorithm maintains the convergence properties of sequential algorithm while it achieves almost linear speedup as the problem size increases.

• Journal of Communications and Networks
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• v.5 no.3
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• pp.197-201
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• 2003

We study in this paper both distributed power control and removal algorithms for multimedia CDMA wireless networks. In our study, users can have different data rates as well as different quality of service (QoS) requirements. We derive a necessary and sufficient condition for the fully distributed power control (FDPC) algorithm to find a feasible power set. We also prove that, if the maximal power level is used at the start, then the distributed constrained power control (DCPC) algorithm is equivalent to the FDPC algorithm. For the connection removal algorithm, we prove that the non-reinitialized removal algorithm finds a feasible power set faster and employs smaller power levels than the reinitialized one does. Performances of some connection removal criteria are also studied. Our simulation results reveal that the smallest normalized CIR (SNC) and largest CIR requirement (LCR) criteria result in smaller outage probability than the smallest CIR (SC) criterion in a multimedia environment.