• Journal of the Korean Society of Marine Environment & Safety
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• v.5 no.2
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• pp.99-111
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• 1999

The object of this study is to get the superior double hull structure to its crashworthiness against collision comparing absorbed energy capacities of its various types with each other, varying material properties, collision positions and velocities, and structural arrangements such as double hull width, web and stringer spaces, etc. Local absorbed energy capacities, failure behaviors and damage extents of their members are also considered during collision in addition to the estimations of their global ones. This paper describes a series of numerical simulations of collisions between DWT 45,000 oil tanker(struck ship) and DWT 10,500 rigid one(striking ships) using Hydrocode LS/DYNA3D. Collisions are assumed to occur at the middle of struck ship with striking one moving at right angle to its centerline. The following remarks were obtained through this study: More flexible the double hull structure is, much superior its crashworthiness against collision is. The increment of double hull width does not give much influence than other factors do. The exact use of material property such as failure strain is also important on the numerical simulation of collision.

• Proceedings of the Korea Multimedia Society Conference
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• 2001.11a
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• pp.569-574
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• 2001

인터넷상에서 가상현실을 표현하기 위한 그래픽스 포맷 표준화가 활발히 진행되고 있다. Virtual Reality Modeling Language 97 (VRML 97)은 이러한 표준화 노력으로 공인된 최근의 한 산물이며, 현재는 Web3D 컨소시움에서 VRML 확장 노드들을 추가하고 XML 문서 형식을 취하는 방향으로 VRML 97을 향상시킨 표준 포맷으로 발전시키기 위한 장을 마련하고 있다. VRML 확장을 위해 일반적으로 요구되는 중요한 요소 중 하나가 교화질의 이미지를 빠르게 얻는 것이다. 영상기반렌더링(Image-Based Rendering (IBR)) 기법은 이를 위한 좋은 방법 중 하나로, 우리는 이런 기능을 VRML에서 사용할 수 있는 VRML 확장 형태로 개발된 도구에 의해 데이터를 만들고 이를 지원하도록 VRML 브라우저를 수정하여, VRML 확장으로써의 IBR 기법의 유용성을 보이고자 한다.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.11a
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• pp.487-490
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• 2006

웹사이트 평가는 서비스의 대상과 방법이 서로 다르기 때문에 정확한 평가를 위해서는 웹사이트 간 특성을 파악하여 상대적인 중요도를 고려해야 한다. 그러나 평가 모형내의 요소에 대한 가중치를 과학적으로 산출하는 방법 및 웹사이트 사용자별 차이를 고려한 연구는 아직 미흡한 실정이다. 본 연구에서는 이러한 문제인식을 가지고 3C-D-T 프레임워크내의 각 평가요소간의 상대적인 중요도를 일반사용자 및 업체사용자 측면에서, 과학적이고 체계적인 방법으로 요인간의 상대적인 중요도를 밝혀내어 정보제공 웹사이트 평가모형으로서의 신뢰성을 확보하고 웹사이트 구축, 운영, 관리시 중요하게 고려해야 할 요소를 제시하고는 것이 목적이다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.26 no.2
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• pp.23-28
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• 2003

This research explains visualization of diagnostic system of 3D CAD data, IGES (Initial Graphics Exchange Specification), by using JNI(Java Native Interface) to connect between C++ and Java programming. The diagnostic system is to analyze IGES clearly by identifying errors and anomalies with respect to the diagnosis of geometry and topology of entities. The output of the system is IGES file including . error information which can be visualized with different colors by several commercial visualization systems. The paper focuses on the visualization of the result IGES which can be extended to web based application over internet.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.9
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• pp.142-150
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• 2003

MDO is one of the efficient methods for huge and multi -functional system design. This paper describes a design collaboration framework with MDO in networked design environment. A prototype of web -based integrated design system was implemented to show sharing and exchange of models and analysis information between MDO modules and collaborative design stations. Server System consists of MDO modules for optimization and modeling module for 3D modeling operation. Client system provide user with graphic interface for shape modeling and system operation. We believe that the proposed approach can be extended to solve real complex multidisciplinary design problems.

• Korean Journal of Computational Design and Engineering
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• v.5 no.1
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• pp.88-94
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• 2000

This paper presents new type remote home automation that can control and manage hi-directionally and efficiently home appliances and home security systems in home through Internet. The system is used virtual reality technology to construct very easy user interface and used Internet as network for remote control. Here, the user interface is 3D GUI which gives user feeling to be at his home on web-browser, and also shows him present state of control objects at home. This system has been implemented on the basis of Java and VRML. In this paper we propose the internet-based remote control system, and show usefulness of the suggested system by applying to home automation system.

• Korean Journal of Computational Design and Engineering
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• v.13 no.6
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• pp.412-420
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• 2008

In order to design the large complex structures like VLFS (Very Large Floating Structures), it is essential the cooperation between the experts in various fields; structural engineering expert, fluid mechanics expert, mooring system engineer, and so on. This paper describes the development of an integrated system to support the cooperative design between various experts and project manager. This integrated system is designed to be operated in Web environment and it contains the support of design DB and 3D graphical tool, negotiation tool for task allocation, and various engineering supporting tools for each design step. The user group of this system can be classified as Project Manager, Engineering Expert, DB Builder, and System Administrator. All of the engineering data is saved after and during the process of the design projects and all participants can be connected by Internet without the limit of time or space constraints.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.11a
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• pp.155-159
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• 2000

현재 Inner-wear매장에서 판매되어지는 제품을 소비자가 구매하려고 할 때 제품을 선택할 수 있는 범위에는 많은 제한적인 요소들이 따른다. 제품의 특성과 매장의 사정에 따라 직접 입어보지 못하는 경우가 비일비재하다. 이런 경우 소비자는 색상과 디자인만으로 제품을 선택할 수밖에 없으며 자신의 신체 Size와는 좀 거리가 먼 상품을 구입할 수 있다. 이러한 현실적 제약으로부터 벗어난, 현재 존재하지 않는 미래의 상황을 연출하고 미리 볼 수 있는 가상현실을 이용하여 입체적으로 연출되는 Inner-wear 상품을 구입 할 수 있도록 하고자 한다. 인터넷상에서 만들어지는 자신의 신체를 직접 확인해 볼 수 있도록 하고 자신이 구매하고자 하는 제품을 골라 가상공간에서 자신의 신체에 직접 입혀보며 자신의 신체에 얼마나 잘 맞는지 확인해 본 후에 구매 할 수 있도록 하는 것이다. 이 시스템은 Web상에서 구동 할 수 있도록 구현되어 일반 소비자들이 어디서나 사이트에 접속하여 구매 할 수 있도록 할 것이다.

• Journal of Communications and Networks
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• v.12 no.3
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• pp.201-208
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• 2010

We propose a new notion of metered signatures. Metered signature is an extension of k-times signatures in which a signer can generate only k signatures. However, the restriction of metered signatures can be more elaborate: It can be used k-times every day or to preserve the order of signed messages in some applications. Any violation of this regulation reveals a secret key or the signature on a predetermined message. The applications includes proxy signatures, limited free downloads, and the rating web site. We give two instances of metered signatures: One is based on the computational Diffie-Hellman problem (CDHP) using a bilinear map and the other is based on the RSA problem. In both schemes, the signature and certificate size and the verification cost are constant with respect to k. Further, we show that the proposed metered signatures admit batch verification of many signatures almost at one verification cost with small security loss.

• IE interfaces
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• v.16 no.1
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• pp.63-69
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• 2003

Virtual Manufacturing is a technology facilitating effective development and agile production of products via computer models representing physical and logical schema and the behavior of the real manufacturing systems including manufacturing resources, environments and products. For the successful application of this technology, a virtual factory as a well-designed and integrated environment is essential. To construct a virtual factory in effective and concurrent manners, a supporting information infrastructure for managing diverse models of virtual factory is very important. In this paper, we constructed the web-based information management system for many engineering activities related with a virtual factory. Using this system, users can handle all information and diverse digital files including attributes, parameters, 3-D CAD files, simulation models, and etc. of a cell, line and whole factory. We expect that this information management system for a virtual factory helps us achieve great time savings and advances in accuracy for construction and maintenance activities of virtual factories.