• Journal of the Korean Society of Groundwater Environment
• /
• v.4 no.4
• /
• pp.223-230
• /
• 1997

DRASTIC system developed by U.S.EPA, is widely used for assessing regional groundwater pollution susceptibility by using hydrogeological factors such as depth to water, net recharge, aquifer media, soil media, topography, vadose zone media, hydraulic conductivity. The system can be applied to site selection of well or waste disposal and landuse for groundwater protection. In this study, hydrogeological spatial database of Younggwang area about topography, drainage, well, geology, soil and landuse was constructed using GIS (Geographic Information System) and regional groundwater pollution susceptibility is analyzed using the spatial database and GIS overlay technique.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.1A
• /
• pp.84-92
• /
• 2004

Eigenstructure-based adaptive beamfoming has advantages of fast convergence and the insentivity to errors in the arrival angle of the desired signal. Eigen-decomposing the sample matrix to extract a basis for the Sl (signal plus interference) subspace, however, is very computationally expensive. In this paper, we present a simple subspace based beamforming which utilizes off-diagonal elements of the sample matrix to estimate the Sl subspace. The outputs of overlapped subarrays are combined to produce the final adaptive output, which improves SINR (signal-to-interference-plus-noise ratio) comapred to exploiting a single subarray. The proposed adaptive beamformer, which employs an efficient angle estimation is very roubust to errors in both the arrival angles and the number of the incident signals, while the eigenstructure-based beamforer suffers from severe performance degradation.

• 한국IT서비스학회:학술대회논문집
• /
• 2009.05a
• /
• pp.453-458
• /
• 2009

정보화가 기업 경쟁력의 핵심 요소로 부각되고 있으며 기업 및 정부기관은 앞 다투어 정보화에 투자하고 있는 상황이다. 정보시스템 개발 프로젝트도 이제는 대형 프로젝트 수가 급증하고 있다. 최근 소프트웨어 CMMi 수준에 관한 인증 여부는 기업 경쟁력의 핵심적인 요인으로 그 중요성이 날로 강조되고 있다. 또한 PMI의 PMBOK는 프로젝트 관리의 바이블 격으로 업종 업태를 불문하고 광범위하게 적용되고 있는 상황이다. 프로젝트 관리자의 관점에서 볼 경우 CMMi 모델과 PMBOK 모델간의 중첩되는 부분, CMMi 프로세스를 실적용 시 관리영역에 대한 혼선 부분, 또한 PMBOK 상위지침의 구체성 미흡 부분에 대한 통합 및 조정이 필요하게 되었다. 현재 상용되는 개발방법론에는 관리적인 요소가 매우 미약하고, 국내에 아직까지 체계적으로 정립된 관리방법론이 없는 상황이다. 따라서, 본 논문에서는 프로젝트 관리자가 숙지해야 하는 프로젝트 관리영역, 프로젝트 관리단계, 제반 절차, 유관 정보시스템과의 연동(Interface) 등을 정보화 개발 프로젝트 생명주기(Life Cycle)에 맞춰 재구성 및 통합하여 프로젝트 관리자(Project Manager)에게 일관된 관점(Single Point of View)을 제시하여 프로젝트 생산성을 제고 하고자 한다.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.39 no.3
• /
• pp.220-227
• /
• 2002

An one-dimensional VLSI array for high speed processing of Fractal image compression was designed. Using again the overlapped input data of adjacent domain blocks in the existing one-dimensional VLSI array, we can save the number of total input for the operations, and so we can save the total computation time. In the design procedure, we considered the data dependences between the input data, reordered the input data to the array, and designed the processing elements. Registers and multiplexors are added for the storing and routing of the input data in some processing elements. Consequently as adding a little hardware, this design shows (N-4B)/4(N-B) times of speed-up compared with the existing array, where N is image size and B is block size.

• Journal of the Korean Institute of Gas
• /
• v.9 no.2 s.27
• /
• pp.16-21
• /
• 2005

Functions of the compression ring plate fixed at the concrete side wall are to connect and support the steel roof plate. It should be designed to endure stably all the loads such as weight of steel roof, inner pressure and concrete weight. Behavior of the compression ring during construction has been analyzed by the finite element method and real measured data. Additionally, on the basis of results from parametric study of design variables for the steel roof a more reasonable design method for the compression ring has been proposed.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.15 no.3
• /
• pp.433-440
• /
• 2002

A branched crack in a semi-infinite plate under uniform tension and bending moment is considered in this study By using the superposition, the stress and moment intensity factors for the branched crack subjected to uniform tension and bending moment we evaluated. The stress intensity factors we obtained by using the finite element method and the J-based mutual integral. The moment intensity factors are calculated by extrapolating the values of the moment new the crack tip. Numerical results lot the normalized stress and moment Intensity factors we shown as functions of the ratio of branched crack length to main crack length and the branching angle.

• Journal of the Society of Naval Architects of Korea
• /
• v.39 no.4
• /
• pp.32-41
• /
• 2002

Present study aims to investigate draft effects on hydro-elastic response of pontoon type VLFS(Very Large Floating Structure). A three dimensional higher-order boundary element method(HOBEM: Hong et al;1999, Choi, Hong and Choi; 2001) is extended to analyze elastic response of structures. Intensive numerical calculations were carried out for box type structure to investigate the draft effect on hydrodynamic forces on pontoon type VLFS. Main attention was paid to wave run-up along the waterline for various cases of draft scantling. It is found that the draft effects on the hydro-elastic response of pontoon type VLFS are important especially in short wave range and shallow water region.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.39 no.2
• /
• pp.97-105
• /
• 2011

This paper was conducted on analytical solution using superposition and FEM analysis in the free vibration analysis of rectangular plates under uniform thermal loadings. Materials of three rectangular plates were aluminum, steel and stainless-steel respectively. Applied temperature conditions were from room temperature to $300^{\circ}C$ and boundary condition was free-free condition. Fully symmetric mode(FSM), fully antisymmetric mode(FASM) and symmetric-antisymmetric mode(SAM) were analyzed.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.8
• /
• pp.3295-3300
• /
• 2012

Three Dimensional finite element method (FEM) was used to obtain the stress intensity factor for subsurface cracks and surface cracks existing in inhomogeneous materials. A geometry model, i.e. a solid containing one or several 3D cracks is defined. Several distributions of local node density are chosen, and then automatically superposed on one another over the geometry model. Nodes are generated by the bubble packing, and ten-noded quadratic tetrahedral solid elements are generated by the Delaunay triangulation techniques. To examine accuracy and efficiency of the present system, the stress intensity factor for a semi-elliptical surface crack in a plate subjected to uniform tension is calculated, and compared with Raju-Newman's solutions. Then the system is applied to analyze interaction effects of two dissimilar semi-elliptical cracks in a plate subjected to uniform tension.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.12
• /
• pp.2271-2276
• /
• 2008

In this paper, we propose a computational integral imaging reconstruction (CIIR) method based on scale-cariant magnification technique for resolution-enhanced 3D images. First, we introduce an interference problem among elemental images in CIIR. Magnification by a large factor causes inference among elemental images when they are applied to the superposition process. Thus, the resolution of reconstructed images is limited. To overcome the interference problem, we propose a method to calculate a minimum magnification factor while CIIR is still valid. Magnification by a new factor enables the Proposed method to reconstruct resolution-enhanced images. In addition, the computational load of the proposed method is less than that of the previous method. To confirm the feasibility of the proposed method, some experiments are carried out and the results are presented.