• Spatial Information Research
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• v.11 no.3
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• pp.227-240
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• 2003

The primary focus of this study is to provide a general methodology which can be utilized to understand and analyze environmental issues such as long term ecosystem dynamics and land use/cover change by development of 2D dynamic landscape models and model-based simulation. Change processes in land cover and ecosystem function can be understood in terms of the spatial and temporal distribution of land cover resources. In development of a system to understand major processes of change and obtain predictive information, first of all, spatial heterogeneity is to be taken into account because landscape spatial pattern affects on land cover change and interaction between different land cover types. Therefore, the relationship between pattern and processes is to be included in the research. Landscape modeling requires different approach depending on the definition, assumption, and rules employed for mechanism behind the processes such as spatial event process, land degradation, deforestration, desertification, and change in an urban environment. The rule-based models are described in the paper for land cover change by natural fires. Finally, a case study is presented as an example using spatial modeling and simulation to study and synthesize patterns and processes at different scales ranging from fine-scale to global scale.

• The Transactions of the Korea Information Processing Society
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• v.6 no.9
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• pp.2384-2392
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• 1999

Software engineers are used to analyse the error behavior of computer programs using test cases which are collected for the testing phase when software errors are detected. In actual software testing and debugging, it is important to adopt dynamic slicing technique which is concerned on all the statements to be affected by the variables of current inputs and to use technique of its implementations. The traditional dynamic slicing has focused on the single slicing criterion algorithm. It has been thought that it is needed to develope and implement algorithm for used multiple criteria variables program slicing, which finds every slicing criterion variable where it is used multiple criteria variables. In this paper, we propose an efficient algorithm to make dynamic program slices when it has used multiple criteria variables. The results of the implementation are presented by the making table on execution history and the dynamic dependence graph. Also we can find that the proposed dynamic program slicing approach using multiple criteria variables is more efficient than the traditional single case algorithm on the practical testing environment.

• Tunnel and Underground Space
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• v.16 no.2 s.61
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• pp.166-178
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• 2006

Recently, the frequency of occurring dynamic events such as earthquakes, explosives blasting and other types of vibration has been increasing. Besides, the chances of exposure for rock discontinuities to free faces get higher as the scale of rock mass structures become larger. For that reason, the frictional behavior of rock joints under dynamic conditions needs to be investigated. In this study, artificially fractured rock joint specimens were prepared in order to examine the dynamic frictional behavior of rough rock joint. Roughness of each specimen was characterized by measuring surface topography using a laser profilometer and a series of shaking table tests was carried out. For mated joints, the static friction angle back-calculated ken the yield acceleration was $2.7^{\circ}$ lower than the tilt angle on average. The averaged dynamic friction angle for unmated joints was $1.8^{\circ}$ lower than the tilt angle. Displacement patterns of sliding block were classified into 4 types and proved to be related to the first order asperity of rock joint. The tilt angle and the static friction angle for mated joints seem to be correlated to micro average inclination angle which represents the second order asperity. The tilt angle and the dynamic friction angle for unmated Joints, however, have no correlation with roughness parameters. Friction angles obtained by shaking table test were lower than those by direct shear test.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1993.07a
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• pp.72-77
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• 1993

최근 연·근해 수산자원의 관리 및 어장조성을 통한 자원관리형 수산업으로의 발상 전환과 양식어장의 고도이용 및 생산성 극대화를 위한 기술개발의 필요성이 날로 증대되고 있다. 이와 더불어 세계연안국들에서는 해양목장화시스템의 구상과 관련한 다양한 수중수산시설물의 건설·이용·관리가 빈번해지고 있다. 이에 따라 다양한 수산 증식시설(어초 등), 양식시설, 어장 관리시설 및 부대시설(해저 취·배수관 등)로 구성되는 수중구조물의 종류도 다양하다(D'Itri, 1985). (중략)

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.6_spc
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• pp.635-643
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• 2016

A stability theory of a damped cantilever column under sub-tangential follower forces is first summarized based on the stability map. It is then demonstrated that internal and external damping can be exactly transformed to Rayleigh damping so that the damping coefficients can be effectively determined using proportional damping. Particularly a parametric study with variation of damping coefficients is performed in association with flutter loads of Beck's column and it is shown that two damping coefficients can be correctly estimated for real systems under the assumption of Rayleigh damping. Finally a frequency equation of a cantilever beam subjected to both a sub-tangentially follower force and two kinds of damping forces is presented in the closed-form and its stability maps are constructed and compared with FE solutions in the practical range of damping coefficients.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.07a
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• pp.99-100
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• 2019

무선 센서 네트워크(Wireless Sensor Network, WSN)에서의 싱크 이동은 전력 문제와 관련하여 해결해야할 중요한 문제이다. 또한 고정된 싱크를 사용하면 노드의 과도한 에너지 소비로 인해 네트워크 성능이 저하될 수 있는 문제점이 있다. 본 논문에서는 센서 노드의 클러스터가 퍼지 로직(Fuzzy Logic)을 기반으로 형성되고 싱크 재배치가 동적 2단계 메커니즘을 사용하여 결정되는 에너지 효율적인 싱크 재배치 기법을 제안한다. 본 논문에서 제안하는 기법은 싱크 재배치에 필요한 통신 오버 헤드를 최소화하고 데이터 패킷의 손실이나 지연을 최소화하여 싱크 재배치를 허용한다. 시뮬레이션 결과 제안 기법이 기존의 WSN의 대표적인 싱크 재배치 기법보다 네트워크 수명과 처리량 측면에서 우수하다는 것을 확인할 수 있었다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.4
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• pp.351-359
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• 2015

In order to exactly evaluate the seismic collapse capacity of a structure, probabilistic approach is required by considering uncertainties related to its structural properties and ground motion. Regardless of the types of uncertainties, they influence on the seismic response of a structures and their effects are required to be estimated. An incremental dynamic analysis(IDA) is useful to investigate uncertainty-propagation due to ground motion. In this study, a 3-story steel moment-resisting frame is selected for a prototype frame and analyzed using the IDA. The uncertainty-propagation is assessed with categorized parameters representing epistemic uncertainties, such as the seismic weight, the inherent damping, the yield strength, and the elastic modulus. To do this, the influence of the uncertainty-propagation to the seismic collapse capacity of the prototype frame is probabilistically evaluated using the incremental dynamic analyses based on the Monte-Carlo simulation sampling with the Latin hypercube method. Of various parameters related to epistemic uncertainty-propagation, the inherent damping is investigated to be the most influential parameter on the seismic collapse capacity of the prototype frame.

• Journal of Korean Society of Transportation
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• v.23 no.8 s.86
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• pp.193-202
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• 2005

Due to the importance of SCM(Supply Chain management) in business logistics. many studies related to the SCM performance measurement have been conducted. However, previous SCM performance measurement models have not reflected both ways, operational efficiency and response for market shift. The aim of this research is to suggest a dynamic model to measure SCM performance both with operational efficiency and response for market shift, based on previous SCOR model. To achieve this aim, we developed a cognitive map-based model described eleven KPIs (Key Performance Indicators) with different weight values. And, to measure response level for market shift, we used the concept of entropy-elasticities. Finally, through some actual cases, merits that have no previous models were shown.

• Journal of KIISE:Databases
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• v.29 no.1
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• pp.34-43
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• 2002

Since traditional static metadata set like Dublin Core has static metadata attributes about bibliography information, integration of metadata for various metadata, problems about standard and extension of metadata must be considered for applying it to new environment. Specially, as event-driven metadata write method included the notion of e-commerce come out for interoperability in digital libraries, traditional metadata management which cannot distinguish between different kinds of update operations to new extension of metadata set occurs unsuitable waiting of update operation. So, improvement is needed about it. In this paper, we show whether alleviative transaction consistency can be applied to digital library or not. Also it would divide newer metadata into static metadata attribute connected in read operation within user read-only transaction and dynamic metadata attribute in update operation within dynamic(e-commerce) update transactions. We propose newer metadata management algorithm considered in classfication of metadata attributes and dynamic update transaction. Using two version for minimal maintenance cost and ARU(Appended Refresh Unit) for dynamic update transaction, to minimize conflict between read and write operations shows fast response time and high recency ratio. As a result of the performance evaluation, we show our algorithm is proved to be better than other algorithms in newer metadata environments.

• The Journal of Society for e-Business Studies
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• v.18 no.2
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• pp.27-46
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• 2013

To reduce time to market for converged services, the service provider needs to combine external services and internal processes together, and IT architecture for converged services has to support it. Service Oriented Architecture (SOA) enables the development of a converged service by combining external services and internal processes effectively. However, it is difficult for the existing SOA methods to support the evolution of a converged service, even though the service which consists of the converged service changes over time. In this paper, we argue that a method for profile-based dynamic service binding is required to support evolution of converged services. In order to identify requirements for the proposed method, a business scenario with a smart athletic equipment is given. We then present the concept and architecture of the method for profile-based dynamic service binding to meet the identified requirements. We also demonstrate a prototype implementation for evaluating the proposed method.