• Journal of Mechanical Science and Technology
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• v.17 no.10
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• pp.1458-1465
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• 2003

An eigenvalue analysis of the circular Mindlin plates with free boundary conditions is presented. The analysis is based on the Chebyshev-Fourier pseudospectral method. Even though the eigenvalues of lower vibration modes tend to convergence more slowly than those of higher vibration modes, the eigenvalues converge for sufficiently fine pseudospectral grid resolutions. The eigenvalues of the axisymmetric modes are computed separately. Numerical results are provided for different grid resolutions and for different thickness-to-radius ratios.

• Journal of computational fluids engineering
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• v.6 no.3
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• pp.51-56
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• 2001

As IT(Information Technology) has been developing, an application engineering is advanced so quickly. Especially, CFD field that is influenced greatly by Computing Power is an outstanding example. In this paper, it says a research tendency of the KISTI Supercomputing Center that performs the CFD research based on IT. The representative researches are the National Grid Project, TeraCluster Construction and development and a supporting plan for Supercomputer users' parallelization.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.372-375
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• 1990

A sinusoidal PWM type inverter using 1GBT and a new instantaneous current tracking control stategy is described. Its utilization as an interface for a grid-connected photovoltaic system with maxmum power tracking capability is explaned, and competer simulation along with waveforms are discussed. Finally, experimental results are analysed by state space avarge method to actual grid-connected systems.

• Archives of design research
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• v.15 no.2
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• pp.125-136
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• 2002

The purpose of this study is to investigate the editorial design of the advertising brochure in relation to the promotion of entering college freshmen. The role and function of the brochure promoting universities have been explained in terms of the editorial design. The special regard is paid to the Grid-system that must be handled with the greatest possible care in editorial design of brochures. In this study, it has not only divided into the three categories (Single Grid-system, Multiple Grid-system and Non-Grid-system) according to the Grid-system, and but also analyzed each case of the modeled college brochure. In the analyses, it is found that the using Grid-system brochures are much more effective than that of the lesser using Grid-system, especia1ly in the communication and design. Therefore, the Grid-system is shown to be crucial tool in the current design process of the college brochures. The suggestion of the using criterion of the Grid-system has also been made for the unity as well as diversity of layout in the editorial design. The study then extends this core object principle with the possible development of the Grid-system that includes the balance of the expression of the contents and the artistic structure of design. Additionally, the relationship between the Grid-system and the visual materials for the creative application to the brochure promoting the universities is presented as the final result of this study.

• Journal of computational fluids engineering
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• v.13 no.3
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• pp.28-34
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• 2008

In engineering application of large eddy simulation, there are still questions as follows grid dependency on numerical results, the effect of upwind scheme against a calculation instability, appropriate boundary conditions dealing with turbulence fluctuation and the performance of SGS models. In this study, in order to develop the LES to the engineering application, large eddy simulation was carried out to investigate the effect of upwind scheme, turbulent subgrid model and the grid dependancy of the flow around a wall-mounted cube in a channel at Re=40,000 based on cubic height and bulk mean velocity. The computed velocities, turbulence quantities, separation and reattachment length were evaluated compared with the experimental results of R. Matinuzzi and C. Tropea.

• Journal of information and communication convergence engineering
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• v.9 no.5
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• pp.567-572
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• 2011

As the mobile devices have powerful CPUs and memories, it is possible to carry the large volumes of design drawings, such as DXF files, on mobile devices. However, since the format of a DXF file is the ASCII, it has the shortcoming where the size of a file is larger than a binary formatted file and it is difficult to display the entities of drawings quickly on mobile devices. In this paper, we design the DXF manager system on a smart phone. To speed up the rate of the display and panning, the DXF manager hires the spatial index, the fixed grid file. We also implement the system on the Samsung Omnia-1$^{(R)}$ to exploit the Windows Mobile$^{(R)}$ operating system.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.255-258
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• 2007

WLCG/EGEE project has a main goal of providing application scientists with access to a geographically distributed computing Grid infrastructure. Currently, WLCG/EGEE infrastructure is the world's largest Grid infrastructure, providing over 20,000 CPUs and about 3 PB disk at 200 international sites and used by over 9 application domains including LHC experiments from high-energy physics. This paper addresses the design and construction of WLCG/EGEE tier-2 propelled by international collaboration with EGEE-II project.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.3
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• pp.354-359
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• 2012

A transformerless converter suitable for multiphase drive application is presented in this paper. The topology employs a cascaded H-bridge rectifier as the interface between the grid and multi inverters which drive the multiphase motor. Compared with the conventional structure, the new topology eliminates the input transformer and also has the advantages such as four quadrant operation, simple configuration, low cost, high efficiency, and so on. The control strategies for the grid-side cascade H-bridge rectifier and the motor-side inverter are studied accordingly. Based on the multi-rotational reference frame, modular control scheme is developed to regulate the multiphase drive system. Simulation results show the proper operation of the proposed topology and the corresponding control strategy.

• Korea Journal of Hospital Management
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• v.14 no.2
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• pp.21-40
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• 2009

The importance-performance analysis (IPA) is a widely used analytical technique that produces a priority of managerial attention for the customer satisfaction. This study attempted to compare various different approaches of IPA such as direct and indirect measurement of importance, and traditional four quadrants grid model and diagonal grid model of IPA. Data on 17 inpatient service quality attributes were collected from 234 inpatients of a general hospital. Eight IPA grids were produced to compare the result of each model. Based on the study results the strength and weakness of each model were discussed, and a set of recommendations for practical application of the IPA in hospital settings was suggested.

• Proceedings of the Korean Society of Computer Information Conference
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• 2011.06a
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• pp.115-118
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• 2011

인류를 구할 8가지 기술 중 한가지로 스마트 그리드(Smart Grid)가 소개된 바 있다. 즉 에너지 사용의 효율성을 높여 전력량과 비용을 줄이고 전력 공급자와 소비자 간의 실시간 정보교환이 가능한 지능형 전력망이라 할 수 있다. 그러나 스마트 그리드의 취약점들로 인하여, Smart Meter가 해킹을 당해 정전으로 인한 대규모 피해가 예상 될 수 있다. 본 논문에서는 Smart Meter에 대한 취약점 분석을 실시하고, Smart Meter의 Gateway 보안을 위해서 접근제어와 인증을 통해, 사용자의 접근과 개폐에 대한 보안을 실시한다. 범죄가 발생했을 포렌식 자료를 통한 법적 책임에 관한 내용을 연구한다.