• Proceedings of the IEEK Conference
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• 2002.06b
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• pp.109-112
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• 2002

This paper presents relationship between the dynamic behavior of an asynchronous linear pipeline (ALP) and the performance of the ALP as buffers are allocated. Then the relationship is used in order to characterize a local optimum situation on the buffer design space of the ALP. Using the characterization we propose an efficient algorithm optimizing buffer allocation on an ALP in order to achieve its average case performance. Without the loss of optimality, our algorithm works in linear time complexity so it achieves fast buffer-configuration optimization. This paper makes two contributions. First, it describes relationship between the performance characteristics of an ALP and a local optimum on the buffer design space of the ALP. Second, it devises a buffer allocation algorithm finding an optimum solution in linear time complexity.

• Journal of the Korean Operations Research and Management Science Society
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• v.31 no.1
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• pp.117-129
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• 2006

In this paper, we consider broadband satellite networks using MF-TDMA (Multi-Frequency Time Division Multiple Access) scheme. We analyze the number of expected lost packets in each terminal, and mathematically formulate optimal buffer and timeslot allocation model to minimize the weighted sum of the numbers of expected lost packets. We also suggest optimal buffer and timeslot allocation scheme based on Lagrangean relaxation technique to solve the proposed model in a fast time. Extensive experiments show that the proposed scheme provides encouraging results.

• Journal of the Korea Society for Simulation
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• v.10 no.4
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• pp.65-75
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• 2001

This study presents a heuristic algorithm for buffer allocation in FMS(Flexible Manufacturing System). The buffers, which are finite resources in FMS, are responsible for improvement of an overall system utilization. But, until now, the study for buffer allocation in FMS are rarely conducted because of the complexity in FMS. Most studies for buffer allocation had been addressed to the simple production line system. The presented algorithm uses a simulation for the description of system complexity and uses a genetic algorithm for finding better buffer allocation. Lastly, we compare performance of the presented algorithm with that of a simple heuristic, and analyze the experiment results.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.27 no.4
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• pp.15-22
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• 2004

본 논문의 목적은 유한 저장공간을 가지는 대기행렬 시스템에서 완전공유(Complete Sharing), 완전분할(Complete Partitioning), 최소할당공유(Sharing with Minimum Allocation)와 같은 다양한 저장공간 공유방안들을 비교ㆍ분석하는 것으로, 이를 위하여 먼저 각각의 공유방안에서의 대기행렬 안정상태확률을 효율적으로 구할 수 있는 방법이 제시되었다. 다음으로 각각의 저장공간 공유방안을 특징짓는데 필요한 몇 가지 성질들이 규명되었으며, 이를 토대로 각각의 저장공간 공유방안에 대하여 시스템 성능척도인 생산률들을 도출하는 한편, 이들의 대소관계를 파악하고, 수치실험을 통하여 이를 입증하였다.

• Journal of the Korea Society of Computer and Information
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• v.7 no.3
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• pp.122-127
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• 2002

The Weighted Round Robin(na) discipline which is a sort of scheduling algorithm is quite simple and straightforward for handling multiple queues, and by Putting a different weight on each queue. In this paper, we propose new BSW structure, which can execute the WRR scheduling algorithm efficiently. Also, we develop a cell scheduling algorithm which is adapt in the new BSW structure. The Proposed BSW structure and the algorithm is capable of maintaining an allocated VC's weight correctly and decrease of average cell delay and maximum buffer length by serving other VC cell when empty in each VC queue. The proposed algorithm is a structure suitable for na implementation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.4B
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• pp.604-612
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• 2000

In order to satisfy the desired QoS level associated with each existing connection, ATM networks require traffic policing during a connection. Users who respect the contract should receive the function of transparent traffic policing without any interruption. However, contract violations should be detected and mediated immediately. So we propose a CAM type policing controller to allow user cell streams to minimize additional delay. The proposed policing scheme controls policing actions including traffic shaping by suitably spacing cells on each virtual circuit. This policing action is based on parallel processing of multiple cell stream which arrive in ATM multiplexed virtual circuits. We have developed an analytical model of the proposed policing scheme to examine the amount of cell loss and delay, which depends on traffic load, the size of policing buffers and minimum spacing cell time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.8
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• pp.942-949
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• 2016

Efficient routing protocols designed for Wireless Sensor Networks (WSN) can be extended and applied to Internet of Things (IoT) data routing, as IoT can be considered to be an extension from WSN. When the size of the data in IoT is often bigger than in conventional WSNs, existing cluster routing protocol such as LEACH may cause high data loss rate due to its incomplete load balancing. We present an enhanced LEACH-based protocol which can minimize the data loss which is an important performance measure in IoT. In our proposed protocol, the base station estimates the location of nodes by the trilateration technique to make sure optimal number of cluster heads and members in a deterministic manner. We evaluate our proposed protocol via computer simulations in terms of data loss rate and average network lifetime.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.2
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• pp.381-389
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• 1994

In the communication network, multimedia service such as high quality voice, high speed data, image etc. will be added to the existing service. This service generates new requirements for the communication networks. The priority control mechanism can be used to control multimedia traffics generated by many communication systems. The priority mechanism which assigns prioirities to generated cells according to service quality is one of the traffic control. The priority assignment can be divided by priority criterion for each traffic characteristics such as loss sensitivity and delay sensitivity. In this paper, we alnalyzed the partial buffur sharing (PBS) mechani느 as a traffic control reducing the cell loss, and proposed analysis method. We analyzed the PBS mechanism using classical approach as a Markov chain. In order to validata proposed analysis method, simulation is performed using simulation package SIMSCRIPT 11.5. From this results, we confirmed that proposed analysis method can be verified. Also, we presented cell loss probability of ATM network when this results are to be applied to ATM networks.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9A
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• pp.763-773
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• 2003

In this paper, we present a register renaming method for conditional execution out-of-order instruction issue microprocessors. Register renaming method reduces false data dependencies (write after read(WAR) and write after write(WAW)). To implement a conditional execution out-of-order instruction issue microprocessor using register renaming, we use a register file which includes both in-order state physical registers and look-ahead state physical registers to share all logical registers. And we design an in-order state indicator, a renaming state indicator, a physical register assigning indicator, a condition prediction buffer and a reorder buffer. As we utilize the above hardwares, we can do register renaming and trace the in-order state. In this paper, we present an improved register renaming method using smaller hardware resources than conventional register renaming method. And this method eliminates an associative lookup and provides a short recovery time.

• The KIPS Transactions:PartB
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• v.11B no.3
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• pp.361-368
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• 2004

This paper proposes an interactive VOD system to serve truly interactive VCR services using multicast delivery, client buffer and web-caching technique which implements the distributed proxy in Head-End- Network(HNET). This technique adopts some caches in the HNET that consists of a Switching Agent(SA), some Head-End-Nodes(HEN) and many clients. In this model, HENs distributively store the requested video under the control of SA. Also, client buffer dynamically expands to support various VCR playback rate. Thus, interactive services are offered with transmitting video streams from network, HENs and stored streams on buffer. Therefore this technique makes the load of network occur In the limited area, minimizes the additional channel allocation from server and restricts the transmission of duplicated video contents