• Annual Conference on Human and Language Technology
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• 1991.10a
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• pp.238-246
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• 1991

본 논문에서는 한국어 문서를 대상으로 한국어에 관한 형태소 및 구문정보를 이용하고 또한 문장구조상에 나타난 특징들을 고려한 휴리스틱(Heuristic)을 이용하여 각 문장 단위로 축약하는 시스템을 설계한다. 그리고 이 축약 시스템을 평가하기 위한 방법들을 제안한다.

• Journal of Communications and Networks
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• v.12 no.3
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• pp.246-252
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• 2010

A binary linear integer program is formulated for the problem of expanding the capacity of a fiber optic network and routing the traffic to deliver new interactive multimedia services. A two-phase Lagrangian dual search procedure and a Lagrangian heuristic are developed. Computational results show superior performance of the two-phase subgradient optimization compared with the conventional one-phase approach.

• Proceedings of the Korea Multimedia Society Conference
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• 2002.05c
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• pp.524-529
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• 2002

본 논문에서는 매 단계마다 실시되는 여러 사용성 테스트들 중 프로토타입의 사용성 테스트에 초점을 두었다. 또한 휴리스틱 평가 방법에 기초 하여 사용성 평가 과정에서 이용할 수 있는 체크리스트를 설계하였다. 이 체크리스트를 '천연화장품' 전자상거래 사이트의 사용성 평가 과정에 적용한 결과 사용자의 생각을 정확하게 유도해내고 즉각적으로 피드백하여 제작 기간을 단축시키는데 효과적으로 사용되었다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2005.04a
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• pp.359-366
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• 2005

Most engineering optimization are based on numerical linear and nonlinear programming methods that require substantial gradient information and usually seek to improve the solution in the neighborhood of a starting point. These algorithm, however, reveal a limited approach to complicated real-world optimization problems. If there is more than one local optimum in the problem, the result may depend on the selection of an initial point, and the obtained optimal solution may not necessarily be the global optimum. This paper describes a new harmony search(HS) meta-heuristic algorithm-based approach for structural size optimization problems with continuous design variables. This recently developed HS algorithm is conceptualized using the musical process of searching for a perfect state of harmony. It uses a stochastic random search instead of a gradient search so that derivative information is unnecessary. Two classical space truss optimization problems are presented to demonstrate the effectiveness and robustness of the HS algorithm. The results indicate that the proposed approach is a powerful search and optimization technique that may yield better solutions to structural engineering problems than those obtained using current algorithms.

• Smart Structures and Systems
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• v.20 no.1
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• pp.99-114
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• 2017

In cognitive science, it is illustrated how the collective opinions of a group of individuals answers to questions involving quantity estimation. One example of this approach is introduced in this article as Star Graph (SG) algorithm. This graph describes the details of communication among individuals to share their information and make a new decision. A new labyrinthine network of neighbors is defined in the decision-making process of the algorithm. In order to prevent getting trapped in local optima, the neighboring networks are regenerated in each iteration of the algorithm. In this algorithm, the normal distribution is utilized for a group of agents with the best results (guidance group) to replace the existing infeasible solutions. Here, some new functions are introduced to provide a high convergence for the method. These functions not only increase the local and global search capabilities but also require less computational effort. Various benchmark functions and engineering problems are examined and the results are compared with those of some other algorithms to show the capability and performance of the presented method.

• Structural Engineering and Mechanics
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• v.66 no.4
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• pp.465-476
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• 2018

In this paper, a new meta-heuristic optimization method is presented. This new method is named "Numbers Cup Optimization" (NCO). The NCO algorithm is inspired by the sport competitions. In this method, the objective function and the design variables are defined as the team and the team members, respectively. Similar to all cups, teams are arranged in groups and the competitions are performed in each group, separately. The best team in each group is determined by the minimum or maximum value of the objective function. The best teams would be allowed to the next round of the cup, by accomplishing minor changes. These teams get grouped again. This process continues until two teams arrive the final and the champion of the Numbers Cup would be identified. In this algorithm, the next cups (same iterations) will be repeated by the improvement of players' performance. To illustrate the capabilities of the proposed method, some standard functions were selected to optimize. Also, size optimization of three benchmark trusses is performed to test the efficiency of the NCO approach. The results obtained from this study, well illustrate the ability of the NCO in solving the optimization problems.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.1616-1640
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• 2006

In this paper, we deal with a network optimization problem arising from the deployment of Ethernet-based BcN access network. BcN convergence services require that access networks satisfy QoS measures. BcN services have two types of traffics: stream traffic and elastic traffic. Stream traffic uses blocking probability as a QoS measure, while elastic traffic uses delay factor as a QoS measure. Incorporating the QoS requirements, we formulate the problem as a nonlinear mixed-integer programming model. The proposed model seeks to find a minimum cost dimensioning solution, while satisfying the QoS requirement. We propose tabu search heuristic algorithms for solving the problem, and simulate tabu result. We demonstrate the computational efficacy of the proposed algorithm by solving a network design problem.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.58
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• pp.59-69
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• 2000

Development of digital information and internet technology causes the changes of technology environments and companies, and the variety of customer needs has been dynamically changed in terms of integrating information system with customer satisfaction. Moreover a new logistics concept is needed through the sharing information between suppliers and consumers, which maximizes the level of customers service and its flexibility by changing functional-oriented to process-oriented. In other words, Supply Chain Management (SCM) is now considered as a key aspect of business, which controls the flows of information, funds, and goods in the supply chain. Rationalization of transport-delivery system will be one of the most important issues on logistics management to the domestic companies. The companies need the effective delivery system. Especially in the case of delivery system from distribution centers to customers or vendors, it might take a long time to control the delivery system manually because it would be hard to apply the automatic vehicle routing algorithm effectively considering all the practical constraints. Thus this study develops a heuristic algorithm of automatic vehicle delivery support system in terms of grouping by short ranges of vehicle movement utilizing postal coordinates, which satisfies a variety of realistic constraints and reduces controlling time of manual operations. In addition, the performance of the algorithm developed in this study is evaluated through the case study.

• Journal of Korean Institute of Industrial Engineers
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• v.32 no.2
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• pp.111-119
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• 2006

In the last decade, the research of the usability of mobile phones has been a newly evolving area with few established methodologies and realistic practices that ensure capturing usability in evaluation. Thus, there exists a growing demand to explore appropriate evaluation methodologies that evaluate the usability of mobile phones quickly as well as comprehensively. This study aims to develop a task-based usability checklist based on heuristic evaluation in views of mobile phone UI practitioners. A hierarchical structure of UI design elements and usability principles related to mobile phones were developed and then utilized to develop the checklist. In order to demonstrate the practical effectiveness of the proposed checklist, comparative experiments were conducted on the usability checklist and usability testing. A majority of usability problems found by usability testing and additional problems were discovered by the proposed checklist. It is expected that the usability checklist proposed in this study could be used quickly and efficiently by usability practitioners to evaluate the mobile phone UI in the middle of the mobile phone development process.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.784-789
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• 2009

We propose a novel method of procedurally generating climbing plants using L-systems. The goal of this research is to generate geometry for 3D-modelers, where procedurally generated content is used as a base for the final design. The algorithm is fast and efficiently simulates external tropisms such as gravitropism and heliotropism, as well pseudo-tropisms. The structure of the generated climbing plants is discretized into strings of particles expressed using L-systems. The tips of the plant extend the branches by adding particles in its path, forming internodes. A climbing heuristic has been developed that uses the environment as leverage when the plant is climbing, and effectively covers objects on which it grows. A fast method that sprouts leaves on the surface on which the plant is growing has also been developed, along with a heuristic that simulates the decrease in length, radius and leaf size.