• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.220-223
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• 2003

In this paper, we optimize distributed autonomous robotic system based on artificial immune system. Immune system has B-cell and T-cell that are two major types of lymphocytes. B-cells take part in humoral responses that secrete antibodies and T-cells take part in cellular responses that stimulate or suppress cells connected to the immune system. They have communicating network equation, which have many parameters. The distributed autonomous robotics system based on this artificial immune system is modeled on the B-cells and T-cells system. So performance of system is influenced by parameters of immune network equation. We can improve performance of Distributed autonomous robotics system based on artificial immune system.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2009년도 추계학술발표논문집
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• pp.461-465
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• 2009

Normally, a distributed computing environment is flexible in controlling complex embedded systems but their software components are becoming complex as these systems are equipped with several platforms and attached to various electronic devices, sensors, and actuators. These systems requires inter-object communication mechanisms to provide fault tolerant and QoS-enabled middleware service support in a distributed system. Generally, a middleware performs analysis of the parameters to ensure the availability and reliability of data dissemination. This paper focuses in particular to designing an application middleware for the specific scenario to improve the high availability and fault tolerance of data thus improving the QoS (Quality of Service) of a distributed system. The performance of an adaptive and highly reliable middleware can be significant based on the selection of vital parameters of the system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권1호
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• pp.117-135
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• 2016

Performance enhancement is one of the most important issues in high performance distributed computing systems. In such computing systems, online users submit their jobs anytime and anywhere to a set of dynamic resources. Jobs arrival and processes execution times are stochastic. The performance of a distributed computing system can be improved by using an effective load balancing strategy to redistribute the user tasks among computing resources for efficient utilization. This paper presents a multi-class load balancing strategy that balances different classes of user tasks on multiple heterogeneous computing nodes to minimize the per-class mean response time. For a wide range of system parameters, the performance of the proposed multi-class load balancing strategy is compared with that of the random distribution load balancing, and uniform distribution load balancing strategies using simulation. The results show that, the proposed strategy outperforms the other two studied strategies in terms of average task response time, and average computing nodes utilization.

• International Journal of Contents
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• 제1권1호
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• pp.21-28
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• 2005

This paper is about the hardness of Leader Election problem in asynchronous distributed systems in which processes can crash but links are reliable. Recently, the hardness of a problem encountered in the systems is defined with respect to the difficulty to solve it despite failures: a problem is easy if it can be solved in presence of failures, otherwise it is hard [9]. It is shown in [9] that problems are classified as three classes: F (fault-tolerant), NF (Not fault-tolerant) and NFC (NF-completeness). Among those, the class NFC is the hardest problem to solve. It is also shown in [9] that the construction of Perfect Failure Detector (problem P) belongs to NFC. In this paper, we show that Leader Election is also one of NFC problems by using a general reduction protocol that reduces the Leader Election Problem to P. We use a formulation of the Leader Election problem as a prototype to show that it belongs to NFC.

• 대한임베디드공학회논문지
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• 제12권4호
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• pp.239-246
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• 2017

Time synchronization between distributed embedded systems in the Real Time Locating System (RTLS) based on Time Difference of Arrival (TDOA) is one of the most important factors to consider in system design. Clock jitter error between each system causes many difficulties in maintaining such a time synchronization. In this paper, we implemented a system to synchronize clocks between FPGA based distributed embedded systems using the recovery clock of CDR (clock data recovery) used in high speed serial communication to solve the clock jitter error problem. It is experimentally confirmed that the cumulative time error that occurs when the synchronization is not performed through the synchronization logic using the CDR recovery clock can be completely eliminated.

• International Journal of Contents
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• 제8권4호
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• pp.1-6
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• 2012

Mutual Exclusion is one of the most studied topics in distributed systems where processes communicate by asynchronous message passing. It is often necessary for multiple processes at different sites to access a shared resource or data called a critical section (CS) in distributed systems. A number of algorithms have been proposed to solve the mutual exclusion problem in distributed systems. In this paper, we propose the new algorithm which is modified from Garg's algorithm[1] thus works properly in a fault-tolerant system. In our algorithm, after electing the token generator, the elected process generates a new token based on the information of the myreqlist which is kept by every process and the reqdone which is received during election. Consequently, proposed algorithm tolerates any number of process failures and also does even when only one process is alive.

• 대한전기학회논문지
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• 제39권10호
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• pp.1075-1085
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• 1990

This paper presents a new method for the optimal control of the distributed parameter systems by a decentralized computational procedure. Approximate lumped parameter models are derived by using the Galerkin method employing the Legendre polynomials as the basis functions. The distributed parameter systems, however, are transformed into the large scale lumped parameter models. And thus, the decentralized control scheme is introduced to determine the optimal control inputs for the obtained lumped parameter models. In addition, an approach to block pulse functions is applied to solve the optimal control problems of the obtained lumped parameter models. The proposed method is simple and efficient in computation for the optimal control of distributed paramter systems. Illustrative examples given to demonstrate the validity of the presently proposed method.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1999년도 가을 학술발표회 논문집
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• pp.343-350
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• 1999

This study introduce how distributed object technology can be applied effectively to use in a integrated structural design systems environment with the rapid increasement in the use of network technology. The architecture and management models of the developed systems are described by the CORBA(Com mon Object Request Broke Architecture) distribution standard and objects in Java language. The proposed system can be used for communicating with data between remote designers, regardless of the H/W or S/W platforms they use. Introduction of distributed objects methodologies to a Integrated structural design systems provide advanced levels of integration in structural design environment.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -1
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• pp.97-100
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• 2000

In previous research of social dilemma, there is no extended game that the players can select one game out of some social dilemma games. We propose this kind of game as ＂Distributed Social Dilemma＂ In this game, each player tries to acquire the adaptive strategy throughout local interactions. We make use of GA as evolutionary operations. In this paper, our purpose is to examine how the game selection of players influences the evolution of cooperation in distributed social dilemma. In order to examine, we formulate distributed social dilemma by Game Theory and use agent-based simulation that each agent is regard as player

• Journal of Power Electronics
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• 제16권3호
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• pp.1141-1151
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• 2016

This study proposes a novel islanding detection method for distributed photovoltaic (PV) systems with multi-inverters based on a combination of the power line carrier communication and Sandia frequency shift islanding detection methods. A parameter design method is provided for the novel scheme. On the basis of the designed parameters, the effect of frequency measurement errors and grid line impedance on the islanding detection performance of PV systems is analyzed. Experimental results show that the theoretical analysis is correct and that the novel method with the designed parameters has little effect on the power quality of the inverter output current. Non-detection zones are not observed, and a high degree of reliability is achieved. Moreover, the proposed islanding detection method is suitable for distributed PV systems with multi-inverters.