• Water for future
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• v.28 no.1
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• pp.121-132
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• 1995

This paper presents a mathematical model which simulates the Cherepnov water lifter, that can lift water without the use of external energy such as electricity. A theoritical study was conducted to reveal the characteristics of the Cherepnov water lifter that was continuously operated with the aid of the siphon. The mathematical model wal composed of the continuity equation and energy equation, and was coded using FORTRAN language. In this study, the govering flow equation of the lifter were derived and the computer programs of the equations were worked out. The accuracy of the theoretical equations and their solutions was checked by laboratory experimentation. The mathematical model that simulate the Cherepnov water lifter is appeared to be good to predict the behavior of Cherepnov water lifter. Therefore, the mathematical model and the simulation method used in this study could be used in designing of the Cherepnov water lifter.

• Journal of the Korea Institute of Building Construction
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• v.15 no.1
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• pp.115-121
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• 2015

As recent buildings have been enlarged and free-formed, it is hard to represent three-dimensional buildings with two-dimensional drawings and identify design errors, construction errors, difference of construction quantity and construction cost, clash with columns, beams, pipe machinery, and so on. In order to overcome the limitations, BIM(Building Information Modeling) has been used in construction industry. However, BIM in the construction site is not fully facilitated after practical implementation in process control including training, evaluation and analysis of the process. Therefore, in this study, the effect of BIM applied in the construction site is analyzed empirically throughout the survey at the construction site in accordance with the training, evaluation, and implementation of BIM.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.12 no.3
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• pp.116-129
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• 2000

The interaction of incident monochromatic waves with a tensioned, flexible, circular membrane submerged horizontally below free surface is investigated in the frame of three-dimensional linear hydro-elastic theory. The velocity potential is split into two parts i.e. the diffraction potential representing the scattering of incident waves by a rigid circular disk and the radiation potential describing motion induced waves by elastic responses of flexible membrane. The fluid domain is divided into three regions, and the diffraction and radiation potentials in each region are expressed by the Fourier Bessel series. The displacement of circular membrane is expanded with a set of natural functions, which satisfy the membrane equation of motion and boundary conditions. The unknown coefficients in each region are determined by applying the continuity of pressure and normal velocity at the matching boundaries. The results show that various types of wave focusing are possible by controlling the size, submergence depth, and tension of membrane.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.1
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• pp.65-71
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• 2016

The cyber world is organically alive. It continues to evolve as humans interact with it. Real life and virtual reality are directly or indirectly connected through technology at the network terminal. Branding, in the cyber world, is created by BI(Brand Identity), using designed symbols and logotype developed with digital technology. The objective of this study is to improve the brand value of enterprises and organizations through the use of moving images to adapt to the mobile environment in this rapidly changing cyber world. First, the basic concepts of brand identity, structure, and integrated brand identity were studied. Next, case studies of overseas enterprise branding such Swisscom, HP, BBC were analyzed examining their design concepts and implementation of integrated moving brands. Finally, moving brand identity is explored, for value enhancement, in my projects in ACM SIG CHI 2015, HCI Korea 2014, Aegis Ship 'Yulgok YiYi.' with a discussion of design planning and results. This treatise will contribute to the improvement of brand strategy and design in this country.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.1
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• pp.6-10
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• 1987

The authors carried out an experiment to measure the hydrodynamic resistance of the gear and the efficiency of otter board of the midwater trawl, which is the same used in the former experiment in this series of studies. The whole resistance of the gear was measured by a 10 ton scale recording tension meter, and they were analyzed into the shearing force and the drag with relevant factors determined in the former experiments. The results obtained can be summarized as follows: 1. The whole drag of gear T(kg) and the drag of net R sub(N) (kg) can be expressed as T=2.15 v super(1.12). R sub(N)=1.96 v super(1.01) (v: towing speed in m/sec) 2. The formula of estimating the drag of net deduced by Koyama's method can be expressed as R sub(N)=4.3$\times$d/l$\times$abv 3. The shearing force and the drag of otter board is about 19 to 22% and 5 to 7% of the drag of net, respectively. Whereas, the shearing coefficient and the drag coefficient calculated by the resistance and the opening of gear are 1.5 and 0.42, respectively.

• The Journal of the Korea Contents Association
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• v.15 no.11
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• pp.456-466
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• 2015

This study is focusing to the keyword and blog advertising marketing services that are implementing a viral marketing utilizing keyword searches of the search portal and advertiser's blogs with convergent way. Through a case study for the company operating the service to pinpoint consumers to the advertisers site by indirect exposure via keyword advertising blog at the top of the search results, we analyzed the primitive service operation model on transactional relationship between the business players. We have a research purpose to generate improvement alternatives for the company's keyword advertising marketing services and operation solution using the survey study on the service quality perception and the perceptional gap between user groups. As results of study, we founded 4 types of the service solution and 4 models of service operating architecture on the transactional relations, and we recommended some improvements on the service and solution operation based on the SERVQUAL questionnaire analysis of the difference between the ads sponsor group and ads agency group.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1121-1124
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• 2008

저수분석(low flow analysis)은 수자원공학에서 중요한 분야 중 하나이며, 특히 저수량 빈도분석(low flow frequency analysis)의 결과는 저수(貯水)용량의 설계, 물 수급계획, 오염원의 배치 및 관개와 생태계의 보존을 위한 수량과 수질의 관리에 중요하게 사용된다. 그러므로 본 연구에서는 저수량 빈도분석을 위한 점빈도분석을 수행하였으며, 특히 빈도분석에 있어서의 불확실성을 탐색하기 위하여 Bayesian 방법을 적용하고 그 결과를 기존에 사용되던 불확실성 탐색방법과 비교하였다. 본 논문의 I편에서는 Bayesian 방법 중 사전분포(prior distribution)와 우도함수(likelihood function)의 복잡성에 상관없이 계산이 가능한 Bayesian MCMC(Bayesian Markov Chain Monte Carlo) 방법과 Metropolis-Hastings 알고리즘을 사용하기 위한 여러과정의 이론적 배경과 Bayesian 방법에서 가장 중요한 요소인 사전분포를 구축하고 이를 비교 및 평가하였다. 고려된 사전분포는 자료에 기반하지 않은 사전분포와 자료에 기반한 사전분포로써 두 사전분포를 이용하여 Metropolis-Hastings 알고리즘을 수행하고 그 결과를 비교하여 저수량 빈도분석에 합리적인 사전분포를 선정하였다. 또한 알고리즘의 수행과정에서 필요한 제안분포(proposal distribution)를 적용하여 그에 따른 알고리즘의 효율성을 채택률(acceptance rate)을 산정하여 검증해 보았다. 사전분포의 분석 결과, 자료에 기반한 사전분포가 자료에 기반하지 않은 사전분포보다 정확성 및 불확실성의 표현에 있어서 우수한 결과를 제시하는 것을 확인할 수 있었고, 채택률을 이용한 알고리즘의 효용성 역시 기존 연구자들이 제시하였던 만족스러운 범위를 가지는 것을 알 수 있었다. 최종적으로 선정된 사전분포는 본 연구의 II편에서 Bayesian MCMC 방법의 사전분포로 이용되었으며, 그 결과를 기존 불확실성의 추정방법의 하나인 2차 근사식을 이용한 최우추정(maximum likelihood estimation)방법의 결과와 비교하였다.

• The Transactions of the Korea Information Processing Society
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• v.2 no.5
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• pp.721-732
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• 1995

The IPSE(Integrated Project Support Environment) tool can be seen as a result of an attempt to synthesize the key aspects of language-centered, specific methodology-based and toolkit oriented environments, which are current CASE tools into an organic whole. The IPSE approach based on a process model is regarded as an effective way to implement integrated CASE. The PM-CASE(Process Model based CASE) tool is currently a prototype which draw diagrams describing processes by using a new modeling technique. Attributes related with a task of withen the process model should be defined an saved the database. These attributed are used to retrieve the information of products, and to call the tool related which the task. In this paper, TSEE(Process centered Software Engineering Environment) tools are compared and analyzed. By describing the basic concept, architecture and design of PM-CASE tool, a method of building an process model-based CASE tool is proposed be support an effect software development and management.

• Journal of the Korea Society of Computer and Information
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• v.13 no.7
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• pp.127-138
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• 2008

Configuration and data management system for weapon system research and development processes should assist concurrent engineering and collaboration activities for various documents, drawings, part informations and product structure informations. In this thesis we defined the system architecture using the CBD methodology and implemented the component based system development process. Most of the configuration and data management systems consist of three layered system architecture which use the general MVC models. In this thesis we defined four layered system architecture based on EJB structure under J2EE environments. Through the four layered system architecture, we break down the general model layer into two detailed business layers and the ordinary control layer into two system dependent layers. With these four layers, we proposed the methodology that detailed the characteristics of the components. Through the CBD approach and the component based development process, we can get the representation model and implement the actual system of the configuration and data management system for weapon system R&D.

• Journal of the Society of Naval Architects of Korea
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• v.34 no.1
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• pp.77-86
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• 1997

The advanced development in many fields of engineering and science has caused much interests and demands for crashworthiness and non-linear dynamic transient analysis of structure response. Crash and impact problems have a dominant characteristic of large deformation with material plasticity for short time scales. The structural material shows strain rate-dependent behaviors in those cases. Conventional rate-independent constitutive equations used in the general purposed finite analysis programs are inadequate for dynamic finite strain problems. In this paper, a rate-dependent constitutive equation for elastic-plastic material is developed. The plastic stretch rate is modeled based on slip model with dislocation velocity and its density so that there is neither yielding condition, nor loading conditions. Non-linear hardening rule is also introduced for finite strain. Material constants of present constitutive equation are determined by experimental data of mild steel, and the constitutive equation is applied to uniaxile tension loading.