• Proceedings of the Korean Information Science Society Conference
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• 2004.10a
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• pp.634-636
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• 2004

실시간 운영체제는 멀티태스킹 및 ITC(Inter Task Communication)를 제공한다는 면에서는 범용운영체제와 비슷하나, 시간 결정성을 보장해야 한다는 면에서는 일반 운영체제와 다르다. 실시간 시스템에서는 메모리를 할당하는데 있어서 시간 제약을 어기지 않아야 하기 때문에 동적 메모리 할당은 효율적으로 구성되어야 한다. 본 논문에서는 실시간 운영체제 $_{1}$RTOS$^{TM}$에서 메모리 할당에 소요되는 시간을 향상시키기 위해 최대 힙 알고리즘을 적용한 메모리 할당 기법을 설계 및 구현하였다.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10a
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• pp.400-402
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• 1999

그래프 분할을 사용한 레지스터 할당과 Chaitin의 레지스터 할당 방법의 성능을 비교하였다. 실험 데이터로 Appel이 제시한 간섭 그래프를 사용하였고, 각 알고리즘에서 요구되는 최소 레지스터 수를 비교하였다. 그 결과 그래프 분할을 사용한 방법에서 더 적은 수의 레지스터가 요구되었다. 가용 레지스터가 제한되어 있는 경우, 레지스터 요구 수가 감소되면 삽입되는 대피 코드의 수도 감소된다. 대피 코드의 발생이 줄어들면 메모리를 참조하는 인스트럭션의 수가 감소하여 실행시간을 단축시킬 수 있다. 따라서 컴파일러의 최적화 단계에서 그래프 분할 방법을 사용한 레지스터 할당으로 성능 향상을 기대할 수 있다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.87-88
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• 2019

본 논문에서는 D2D 송수신 단말쌍을 결정하는 방법을 쌍대적 관점에서 살펴보기로 한다. 주어진 D2D 송신단말 그룹과 수신단말 그룹에서 에너지 최적화를 위한 D2D 송수신 단말쌍 할당은 송신단말 그룹이 수신단말 그룹이 되고, 수신단말 그룹이 송신단말 그룹이 되는 환경에서도 동일한 송수신 단말쌍이 할당되는 쌍대적 특성이 있음을 증명하도록 한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.11A
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• pp.859-866
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• 2003

In this paper, we designed the bandwidth allocation scheme with priority consideration for upstream channel access of EthernetPON. The objective of our scheme is to control the multi services in more effective way according to their CoS(Class of Service) or QoS(Quality of Service). The designed scheme considers transmission priority in the both side of OLT and ONU. In the OLT's view, the Two-step scheduling algorithm is applied with which we can support multiple bandwidth allocation policies simultaneously, i.e. SBA for the time-sensitive, constant rate transmission services and DBA for the best-effort services. This Two-step scheduling algorithm reduces the scheduling complexity by separating the process of transmission start time decision from the process of grant generation. In the ONU's view, the proposed scheme controls 8 priority queues of the 802.1d recommended 8 service classes. Higher priority queue is serviced in prior during the allowed GATE time from OLT. The OPNET modeling and simulation result compares the performance of each bandwidth allocation policy with SBA or DBA only approach.

• The Journal of the Korea Contents Association
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• v.18 no.8
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• pp.118-126
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• 2018

In order to dominate the multiple-targets of high threat in the initial stage of combat, it is necessary to maximize the combat effect by rapidly firing as many weapons as possible within a short time. Therefore, it is mandatory to establish the effective weapon allocation and utilize them for the combat. In this paper, we propose a weapon assignment algorithm for rapid reaction in multi-target and multi-weapon environments. The proposed algorithm maximizes the combat effect by establishing the fire plan that enables the rapid action with the operation of low complexity. To show the superiority of our algorithm, we implement the evaluation and verification of performances through the simulation and visualization of our algorithm. Our experimental results show that the proposed algorithm perform the effective weapon assignment, which shows the high target assignment rate within the fast hour even under the large-scale battle environments. Therefore, our proposed scheme are expected to be highly useful when it is applied to real weapon systems.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.8
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• pp.1415-1421
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• 2016

There are considerable concern on the methods for the efficient utilization of the test-resources as increasing of the number of the tests for functionality and performance verification of weapon systems. Furthermore, with an increase in the complexity of the resource assignment the decision support is required. Test resource allocation is basically the same problems as conventional NP-hard FJSP(Flexible Job Shop Problem), therefore empirical test resource allocation method that has been used in many decades is limited in the time performance. Although research has been conducted applying the genetic algorithm to the FJSP, it is limited in the test resource allocation domain in which more than one machine is necessary for a single operation. In this paper, a variable group genetic algorithm is proposed. The algorithm is expected to improve the test plan efficiency by automating and optimizing the existing manual based allocation. The simulation result shows that the algorithm could be applicable to the test plan.

• The Transactions of the Korea Information Processing Society
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• v.6 no.6
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• pp.1502-1510
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• 1999

In adaptive job allocation method for multiprocessor systems a job is folded, or split in two halves, to fit for an available subcube in order to reduce the waiting time of jobs. In this method, however, since a job is folded whenever a subcube with the proper size is not found, the prolonged execution time caused by job split may override the savings in waiting time, in which case the total adaptive jobs may be increased. In this paper, an improved adaptive job allocation algorithm, called Estimate-fold allocation, Is presented and evaluated. The proposed algorithm estimates the costs and takes the better of two alternatives ; folding right away and waiting until a bigger subcube becomes available. The average total job execution cost of our algorithm is calculated and compared to those of the conventional adaptive, buddy, and gray-code algorithms through simulations. The results shows that our proposed algorithm performs better than others.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.3A
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• pp.223-232
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• 2004

In this paper we propose the hierarchical-based dynamic bandwidth allocation algorithm for multi-class services in Ethernet-PON. The proposed algorithm consists of the high level scheduler in OLT and the low level scheduler in ONU. The hierarchical architecture is able to provide scalability and resource efficiency in Ethernet-PON which has the distributed nature of the scheduling domain, with queues and the scheduler located at a large distance from each other. We also propose three dynamic bandwidth allocation algorithms for the low level scheduler: Proportional Allocation algorithm, Maximum Request First Allocation (MRFA) algorithm and High Priority First Allocation (HPFA) algorithm. We implement the Ethernet-PON standardized in the IEEE 802,3ah using OPNET. We also evaluate and analyze the performance for the proposed algorithms in terms of channel utilization, queuing delay and the amount of remainder.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10B
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• pp.964-972
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• 2009

Wireless mesh network (WMN) is emerging a future core technology to resolve many problems derived from exist wireless networks by employing multi-interface and multi-channel. Ability to utilize multiple channels in WMNs substantially increases the effective bandwidth available to wireless network nodes. However, minimum interference channel assignment algorithms are required to use the effective bandwidth in multi-channel environments. This paper proposes a cluster-based minimum interference channel assignment (MI-CA) algorithm to improve the performance of WMN. The MI-CA algorithm is consists of Inter-Cluster and Intra-Cluster Intrchannel assignment between clusters and in the internal clusters, respectively. The Inter-Cluster channel assignment assigns a barebone channel to cluster heads and border nodes based on minimum spanning tree (MST) and the Intra-Cluster channel assignment minimizes channel interference by reassigning ortasgonal channels between cluster mespann. Our simheation results show that MI-CA can improve the performance of WMNs by minimizing channel interference.

• Journal of Korea Society of Industrial Information Systems
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• v.27 no.4
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• pp.37-45
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• 2022

In this paper, a multi agent-multi task assignment problem, which is a representative problem of combinatorial optimization, is presented. The objective of the problem is to determine the coordinated agent-task assignment that maximizes the sum of the achievement rates of each task. The achievement rate is represented as a concave down increasing function according to the number of agents assigned to the task. The problem is expressed as an NP-hard problem with a non-linear objective function. In this paper, to solve the assignment problem, we propose a hybrid cross-entropy algorithm as an effective and efficient solution methodology. In fact, the general cross-entropy algorithm might have drawbacks (e.g., slow update of parameters and premature convergence) according to problem situations. Compared to the general cross-entropy algorithm, the proposed method is designed to be less likely to have the two drawbacks. We show that the performances of the proposed methods are better than those of the general cross-entropy algorithm through numerical experiments.