• Asia pacific journal of information systems
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• 제8권2호
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• pp.1-18
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• 1998

As the management and preservation of the environment become an important social issue, information required to support environmental task is required. So, there is an increasing demand for environmental information and appropriate systems to manage it. The vast volume of environmental data is distributed in different knowledge domains and systems. Environmental data objects have the complex structure containing environmental quality data and attribute data. Environmental information systems must be able to address these properties. This research has aimed at constructing well-defined schema design of environmental data, and making system architecture that environmental data kept by authorities should be made available to the public user. There are 3 major components in environmental information systems architecture ; User interface, Catalog libraries, Communication Provider. Web browsers provide consistent and intuitive user interfaces on Internet. The communication provider is a collection of diverse CGI functions. The main roles of the CGIs are to build interfaces between the Web, databases. Catalog libraries is libraries of various matadata including administration matadata. Administration matadata support the environmental administration and the managerial aspects of environmental data rather than explain a database itself or its properties.

• 시스템엔지니어링학술지
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• 제14권1호
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• pp.83-88
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• 2018

Engineering is a sector with more than three times the industrial effectiveness of manufacturing. In the domestic engineering life cycle, the Operations & Maintenance (O&M) phase is a relatively high level of technology. Based on accumulated knowledge of O&M phase, it is necessary to advance operating technology and expand overseas O&M market expenditure. This study is the early stage of knowledge-based power plant O&M service framework reference model. In this study, we propose a conceptual model of architecture framework for power plant O&M. We survey the architecture framework and reference model and propose conceptual model of architecture framework for power plant O&M. The conceptual model of architecture framework for power plant O&M consists of stakeholder, O&M scenario, O&M technology. In particular, the O&M technology is defined as the fourth industrial revolution intelligence information technology. We defined a meta model from the conceptual model to define the power plant O&M architecture framework. In the future, we intend to development an architecture framework from the conceptual model and meta model.

• 한국산업정보학회논문지
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• 제10권3호
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• pp.57-63
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• 2005

Kim과 Fenn등은 LFSR 구조를 이용한 두 가지 구조의 효율적인 모듈러 AB 곱셈기를 구현하였다. 그들의 구조는 기약다항식으로 모든 계수가 1인 속성의 AOP를 이용함으로서 기존의 곱셈기들보다 효율적인 구조복잡도를 가졌다. 본 논문에서는 Kim의 곱셈기보다 효율적인 공간 복잡도를 가진 LFSR(Linear Feedback Shift Register) 구조 기반의 모듈러 $AB^2$ 곱셈기와 모듈러 지수승기를 제안한다. 본 논문에서 제안한 구조도 Kim의 구조에서와 같이 기약다항식으로 AOP를 사용한다. 시뮬레이션 결과 본 논문에서 제안한 $AB^2$ 곱셈기가 구조복잡도 면에서 Kim의 구조보다 XOR와 AND 게이트의 개수를 약 $50\%$ 정도 줄일 수 있었다. 제안한 구조는 공개키 암호화 시스템을 위한 기본구조로 사용될 수 있을 것이다.

• 한국해양공학회지
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• 제33권4호
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• pp.350-357
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• 2019

The development of marine technology is expected to increase the demand for marine plants because of increasing oil prices. Therefore, there is also expected to be an increase in the demand for cylindrical structures such as URF (umbilical, riser, flowline) structures and spars, which are used operating in various seas. However, a cylindrical structure experiences vortex induced motion (VIM) in a current. In particular, for risers and umbilicals, it is important to identify the characteristics of the VIM because interference between structures can occur. In addition, various studies have been conducted to reduce VIM because it is the cause of fatigue damage to structures. The helical strake, which was developed for VIM reduction, has an excellent VIM reduction performance, but is difficult to install on structures and has a negative effect on heave motion. Therefore, the purpose of this study was to supplement the shortcomings of the helical strake and develop a high-performance reduction device. In the reduction device developed in this study, a string is placed around the structure inside the flow, causing vibration. The vibration of this string causes a small turbulence in the flow field, reducing the VIM effect on the structure. Finally, in this study, the 2-DOF motion characteristics of models without a suppression device, models with a helical strake, and models with a string were investigated, and their reduction performances were compared through model tests.

• 한국해양공학회지
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• 제30권1호
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• pp.1-9
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• 2016

In order to convert wave energy into large quantities of high-efficiency power, it is necessary to study the optimal converter system appropriate for the environment of a specific open ocean area. A wave energy converter system with a counterweight converts the translation energy induced from the heave motion of a buoy into rotary energy. This experimental study evaluated the primary energy conversion efficiency of the system, which was installed on an ocean generating basin with a power take-off system. Moreover, this study analyzed the energy conversion performance according to the weight condition of the buoy, counter-weight, and flywheel by changing the load torque and wave period. Therefore, these results could be useful as basic data such as for the optimal design of a wave energy converter with a counterweight and improved energy conversion efficiency.

• Steel and Composite Structures
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• 제18권4호
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• pp.971-983
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• 2015

To promote greater acceptance and use of composite RCS systems, a two-bay two-story frame specimen with improved composite RCS joint details was tested in the laboratory under reversed cyclic loading. The test revealed superior seismic performance with stable load versus story drift response and excellent deformation capacity for an inter-story drift ratio up to 1/25. It was found that the failure process of the frame meets the strong-column weak-beam criterion. Furthermore, cracking inter-story drift ratio and ultimate inter-story drift ratio both satisfy the limitation prescribed by the design code. Additionally, inter-story drift ratios at yielding and peak load stage provide reference data for Performance-Based Seismic Design (PBSD) approaches for composite RCS frames. An advantage over conventional reinforced concrete and steel moment frame systems is that the displacement ductility coefficient of the RCS frame system is much larger. To conclude, the test results prove that composite RCS frame systems perform satisfactorily under simulated earthquake action, which further validates the reliability of this innovative system. Based on the test result, some suggestions are presented for the design of composite RCS frame systems.

• 수산해양기술연구
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• 제47권3호
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• pp.257-266
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• 2011

Recently, the manufacturers of life-jacket are very interested in the acquisition of USCG(US Coast Guard) approval because the acquisition of USCG approval has an important role in the purchasing decision of the buyer's. Be based on criterion of USCG, we studied how to predict the change of floating position of human model with life-jacket to verify the backside restore. For this, in this study, the human model and the lifejacket was modeled in three dimension, the application program for prediction of floating position was developed, and plugged-in commercial program.

• 수산해양기술연구
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• 제44권1호
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• pp.57-67
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• 2008

Recently, Korean shipbuilding industry is keeping up the position of world wide No. 1 in world shipbuilding market share. It is caused by endless efforts to develope new technologies and methods and fast development of IT technologies in Korea, to raise up its productivities and efficiency in shipbuilding industry with many kinds of optimizing methods including genetic algorithm or artificial life algorithm... etc. In this paper, we have suggested the artificial life algorithm with relay search micro genetic algorithm. and we have improved a defect of simple genetic algorithm for its slow convergence speed and added a variety of solution candidates with applying relay search simple genetic algorithm. Finally, we have developed intelligent agent system for ship CAE modeling. We have tried to offer some conveniences a ship engineer for repeated ship CAE modeling by changing ship design repeatedly and to increase its accuracy of a ship model with it.

• 대한조선학회논문집
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• 제43권4호
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• pp.504-511
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• 2006

In this paper a modern sailing boat for our costal area was developed by using the traditional boat hull form. Main particulars of design ship were determined by using the statistical values. Hull form was varied from the traditional boat hull form which was selected by the previous study and modified to fit Lateen sail. The appendage, rudder and keel were designed for good performance of against wind sailing. The performance of hull form was examined and the results were shown.

• 대한조선학회논문집
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• 제42권1호
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• pp.50-56
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• 2005

The performance of Traditional Korean Fishing Boat is surveyed based on Report on Investigation of Korean Fishing Boat. The characteristics of Traditional Korean fishing Boat of hull form, rudder, sail are studied from the view point of modern sailing boat design. As a result we find her hull form is an excellent candidate of mother ship for modern boat design and the great sized rudder of Traditional Korean Fishing Boat makes a role of the centerboard of modern sailing host. And also we find the sail of Traditional Korean fishing Boat is more useful for sailing against the wind direction than an ordinary Lug sail.