• Journal of the Korea Society for Simulation
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• v.19 no.1
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• pp.73-82
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• 2010

Productivity improvement is considered as one of hot potato topics in international shipyards by the increasing amount of orders. In order to improve productivity of lines, shipbuilders have been researching and developing new work method, process automation, advanced planning and scheduling and so on. An optimization approach was accomplished on short-term scheduling of subassembly lines in this research. The problem of subassembly line scheduling turned out to be a non-deterministic polynomial time problem with regard to SKID pattern’s sequence and worker assignment to each station. The problem was applied by simulated annealing algorithm, one of meta-heuristic methods. The algorithm was aimed to avoid local minimum value by changing results with probability function. The optimization result was compared with discrete-event simulation's to propose what pros and cons were. This paper will help planners work on scheduling and decision-making to complete their task by evaluation.

• Journal of Internet Computing and Services
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• v.6 no.6
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• pp.99-106
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• 2005

The task scheduling in multiprocessor system Is one of the key elements in the effective utilization of multiprocessor systems. The optimal assignment of tasks to multiprocessor is, in almost all practical cases, an NP hard problem. Consequently various modern heuristics based algorithms have been proposed for practical reason. Recently, several approaches using Genetic Algorithm (GA) are proposed. However, these algorithms have only one objective such as minimizing cost and makespan. This paper proposes a new task scheduling algorithm using Genetic Algorithm combined simulated annealing (GA+SA) on multiprocessor environment. In solution algorithms, the Genetic Algorithm (GA) and the simulated annealing (SA) are cooperatively used. In this method. the convergence of GA is improved by introducing the probability of SA as the criterion for acceptance of new trial solution. The objective of proposed scheduling algorithm is to minimize makespan and total number of processors used. The effectiveness of the proposed algorithm is shown through simulation studies. In simulation studies, the results of proposed algorithm show better than that of other algorithms.

• The KIPS Transactions:PartB
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• v.17B no.1
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• pp.85-92
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• 2010

A shallow semantic parsing system analyzes the relationship that a syntactic constituent of the sentence has with a predicate. It identifies semantic arguments representing agent, patient, instrument, etc. of the predicate. In this study, we propose a two-phase shallow semantic parsing model which consists of the identification phase and the classification phase. We first find the boundary of semantic arguments from partial syntactic parsing results, and then assign appropriate semantic roles to the identified semantic arguments. By taking the sequential two-phase approach, we can alleviate the unbalanced class distribution problem, and select the features appropriate for each task. Experiments show the relative contribution of each phase on the test data.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.12
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• pp.1539-1547
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• 1999

캐리-세이브 가산기 (CSA)는 회로 설계 과정에서 빠른 연산 수행을 위해 가장 널리 이용되는 연산기 중의 하나이다. 그러나, 현재까지 산업체에서 CSA를 이용한 설계는 설계자의 경험에 따른 수작업에 의존하고 있고 그 결과 최적의 회로를 만들기 위해 매우 많은 시간과 노력이 소비되고 있다. 이에 따라 최근 CSA를 기초로 하는 회로 합성 자동화 기법에 대한 연구의 필요성이 대두되고 있는 상황에서, 본 논문은 연산 속도를 최적화하는 효율적인 CSA 할당 알고리즘을 제안한다. 우리는 CSA 할당 문제를 2단계로 접근한다: (1) 연산식의 멀티 비트 입력들만을 고려하여 최소 수행 속도 (optimal-delay)의 CSA 트리를 할당한다; (2) (1)에서 구한 CSA 트리의 수행 속도 증가가 최소화 (minimal increase of delay) 되는 방향으로 CSA들의 캐리 입력 포트들에 나머지 싱글 비트 입력들을 배정한다. 실제 실험에서 우리의 제안된 알고리즘을 적용하여 연산식들의 회로 속도를 회로 면적의 증가 없이 상당한 수준까지 줄일 수 있었다.Abstract Carry-save-adder (CSA) is one of the most widely used implementations for fast arithmetics in industry. However, optimizing arithmetic circuits using CSAs is mostly carried out by the designer manually based on his/her design experience, which is a very time-consuming and error-prone task. To overcome this limitation, in this paper we propose an effective synthesis algorithm for solving the problem of finding an allocation of CSAs with a minimal timing for an arithmetic expression. Specifically, we propose a two step approach: (1) allocating a delay-optimal CSA tree for the multi-bit inputs of the arithmetic expression and (2) determining the assignment of the single-bit inputs to carry inputs of the CSAs which leads to a minimal increase of delay of the CSA tree obtained in step (1). For a number of arithmetic expressions, we found that our approach is very effective, reducing the timing of the circuits significantly without increasing the circuit area.

• Journal of Advanced Navigation Technology
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• v.15 no.1
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• pp.124-129
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• 2011

In the process of cooperation which can be the best proposals for resolving complex problems in computing domain, the way of team organizing is one of the most important aspects for succeeding the goal. Especially in ubiquitous computing environment, where the participants of a team are selected from the heterogeneous computing objects which are deployed by other providers for their own goals, finding the relevant teammate can be regarded as the most important factor for determining the success or failure of the given problem. In this paper, we propose a method of finding teammate and assigning a role, which is a sub task of cooperation, by comparing the attributes of the computing object and the requirement of the role such as capability of functions, loyalty for the given team, and harmony with other teammates. By considering the situationally changing weights of each attributes, this method can be suited for dynamic computing environment where the cooperation should be executed with dynamically in/out computing objects and satisfy the dynamically chaining constraints.

• Journal of Internet Computing and Services
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• v.5 no.1
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• pp.25-32
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• 2004

Mobile computing environment makes it possible for computing activities to be maintained during movement even if a user changes its network point of attachment. Mobile IP is a standard protocol designed to be used in such mobile computing environment. However, Mobile IP has a drawback to incur a lot of handoff delays and waste network resources, since CoA(Care of Address) registration packets need to go through a HA(Home Agent) first whenever a mobile node moves. To solve this long-standing problem, this paper proposes a new scheme that, for infra-domain movement, efficiently performs local handoff without notifying the HA Specifically, based on the notion of load balance, the proposed scheme allows every FA(Foreign Agent) in a domain to become the root FA(also known as domain FA) dynamically, thus distributing the registration task into many other foreign agents. The dynamic root assignment through load balancing ultimately leads to fast network response due to less frequent transmission of registration packets.

• Journal of Korea Society of Industrial Information Systems
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• v.27 no.6
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• pp.69-75
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• 2022

We propose energy-efficient scheduling considering real-time constraints and energy efficiency in smart mobile with heterogeneous multi-core structure. Recently, high-performance applications such as VR, AR, and 3D game require real-time and high-level processings. The big.LITTLE architecture is applied to smart mobiles devices for high performance and high energy efficiency. However, there is a problem that the energy saving effect is reduced because LITTLE cores are not properly utilized. This paper proposes a heterogeneous multi-core assignment technique that improves real-time performance and high energy efficiency with big.LITTLE architecture. Our proposed method optimizes the energy consumption and the execution time by predicting the actual task execution time using SVM (Support Vector Machine). Experiments on an off-the-shelf smartphone show that the proposed method reduces energy consumption while ensuring the similar execution time to legacy schemes.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.59-60
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• 2023

The automation of container terminals is an important factor that determines port competitiveness, and global advanced ports tend to strengthen their competitiveness through container terminal automation. The operational efficiency of the AGV, which is an essential transport equipment of the automated terminal, can improve the productivity of the automated terminal. The operation of AGVs in automated container terminals differs from that of conventional container terminals, as it is based on an automated system in which AGVs travel along designated paths and operate according to assigned tasks, requiring consideration of factors such as workload, congestion, and collisions. To prevent such problems and improve the efficiency of AGV operations, a more sophisticated model is necessary. Thus, this paper proposes an AGV scheduling model that takes into account the AGV travel path and task assignment within the terminal The model prevent the problem of deadlock and. various cases are generated by changing AGV algebra and number of tasks to create AGV driving situations and evaluate the proposed algorithm through algorithm and optimization analysis.

• The Korean Journal of Archival Studies
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• no.37
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• pp.189-237
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• 2013

Since central governments began to establish and use the Standard Records Management System(RMS) in 2007, more and more local governments and other public organizations have constructed RMS. RMS is the essential tool for records management in electronic environments, but it is not known how well the functions of RMS reflect standards and practice related records management or how many records managers use RMS in performing their works. This paper deals with analyzing the evaluation of 'classification & disposal schedule management' function in RMS. 'Classification & disposal schedule management' function has 4 subfunctions of review of classification & preservation period, management of the schedule items, assignment of classification scheme and reclassification. Classification and disposal schedule is at the heart of intellectual control of records and core area of records management. So it is important to analyze whether this function plays well a role in RMS or not. This research carried out evaluation of function and use about classification & disposal schedule management in RMS. Functional evaluation is to compare and analyze how well RMS meets the functional requirements which home and foreign standards give. Use evaluation is to investigate how records managers use RMS in accomplishing their task of managing classification & disposal schedule and to look into what is the problem with the use. This paper could get the implications through the survey of records managers who are working at central governments, regional local governments and basic local governments. And these implications are considered in institutional, functional, use and administrative aspect. It is important to communicate with stakeholders so that 'classification & disposal schedule management' function, further, all functions of the RMS in practice of records management could be used smoothly. Users of RMS have to raise demands or call for technical solutions of the problems which come up in use, while RMS developers and administrators must make more of an effort to satisfy their demands, reflect them on the RMS and enhance the system.