• Journal of Ship and Ocean Technology
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• 제8권1호
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• pp.10-30
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• 2004

High-fidelity RANS simulations are presented for a ducted marine propulsor, including verification ＆ validation (V＆V) using available experimental fluid dynamics (EFD) data. CFDSHIP-IOWA is used with $\textsc{k}-\omega$ turbulence model and extensions for relative rotating coordinate system and Chimera overset grids. The mesh interpolation code PEGASUS is used for the exchange of the flow information between the overset grids. Intervals V＆V for thrust, torque, and profile averaged radial velocity just downstream of rotor tip are reasonable in comparison with previous results. Flow pattern displays interaction and merging of tip-leakage and trailing edge vortices. In interaction region, multiple peaks and vorticity are smaller, whereas in merging region, better agreement with EFD. Tip-leakage vortex core position, size, circulation, and cavitation patterns for $\sigma=5$ also show a good agreement with EFD, although vortex core size is larger and circulation in interaction region is smaller.

• 전자공학회논문지A
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• 제33A권4호
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• pp.112-120
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• 1996

With the MOsES (mask oxide sidewall etch scheme)process which uses the conventional i-line stepper and isotropic wet etching, CMOSFET's with fine gate pattern of 0.1.mu.m CMOSFET device, the screening oxide is deposited before the low energy ion implantation for source/drain extensions and two step sidewall scheme is adopted. Through the characterization of 0.1.mu.m CMOSFET device, it is found that the screening oxide deposition sheme has larger capability of suppressing the short channel effects than two step sidewall schem. In cse of 200.angs.-thick screening oxide deposition, both NMOSFET and PMOSFET maintain good subthreshold characteristics down to 0.1.mu.m effective channel lengths, and show affordable drain saturation current reduction and low impact ionization rates.

• Nuclear Engineering and Technology
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• 제28권3호
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• pp.320-330
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• 1996

The streaming rays(SR) method is improved and extended to multigroup, anisotropic scattering, and three-dimensional angular space(x-y-z(infinite))problems. This method is applied to the shielding problems in which the ray effect occurs seriously. For verification, the results of MORSE-CG code are used as reference solution and the results of TWODANT code are compared. The results show that solutions of the SR method are much better than those of the TWODANT code and are in good agreement with those of the MORSE-CG code. Also, to reduce computing time, two acceleration algorithms are implemented in the SR method : the standard coarse-mesh rebalance and a new angular two-grid acceleration.

• 융복합기술연구소 논문집
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• 제4권1호
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• pp.37-41
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• 2014

For the analysis of lifting surface at high angle of attack, a Nonlinear Vortex Lattice Method(NLVLM) was used. The NLVLM is intented to compute the interactions between lifting surfaces and separated vertical flow. The lifting surfaces are represented by a lattice of discrete vortex rings. And wakes are represented by families of non-lintersecting, semi-infinite vortex line segments. The image method also used to analyze the ground effect. It is found that vortex lines separated from lifting surfaces represent the separated flows successfully. Although the present method is applied for the rectangular wing and delta wing, extensions can be possible for the arbitrary lifting surfaces. The Present results show good agreement with experimental data.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2012년도 춘계학술발표대회
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• pp.336-339
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• 2012

VTK is a free but professional development platform for images three-dimensional (3D) reconstruction and processing. It is powerful, open-source, and users can customize their own needs by self-development of great flexibility. To give the doctors more and detailed information by simulate dissection to the 3-D brain MRI image after reconstruction. A Visualization System (VS) is proposed to achieve 3D brain reconstruction and virtual dissection functions. Based on the free VTK visualization development platform and Visual Studio 2010 IDE development tools, through C++ language, using real people's MRI brain dataset, we realized the images 3D reconstruction and also its applications and extensions correspondingly. The display effect of the reconstructed 3D image is well and intuitive. With the related operations such as measurement, virtual dissection and so on, the good results we desired could be achieved.

• Journal of Mechanical Science and Technology
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• 제15권7호
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• pp.951-961
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• 2001

The present article presents an extension to the computational model for spray/wall interaction and liquid film processes that has been dealt with in the earlier studies (Lee and Ryou, 2000a). The extensions incorporate film spread due to impingement forces and dynamic motion induced by film inertia to predict the dynamic characteristics of wall films effectively. The film model includes the impingement pressure of droplets, tangential momentum transfer due to the impinging droplets on the film surface and the gas shear force at the film surface. Validation of the spray/wall interaction model and the film model was carried out for non-evaporative diesel sprays against several sources of experimental data. The computational model for spray/wall interactions was in good agreement with experimental data for both spray radius and height. The film model in the present work was better than the previous static film model, indicating that the dynamic effects of film motion should be considered for wall films. On the overall the present film model was acceptable for predication of the film radius and thickness.

• 한국유기농업학회지
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• 제9권4호
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• pp.95-111
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• 2001

To carry out the Integrated Fruit Production(IFP), researches on cover crops as well the Integrated Pest Management(IPM) and the Integrated Nutrition Management(INM) should be very important. These concepts are neither clear nor connective till now. The researches on cover crops in Europe and USA are being kept within the category of IFP. Main researches on fruit trees for sustainable agriculture in Italy are new variety creation, development of growing techniques, pest and disease control, and cover crops management, etc. It is necessary of fruit industry in Korea to maintain good quality and taco-friendly fruit production. For this goal, we need international cooperation with highly developed countries in Europe. In first step, we should enlarge research areas and analyze results obtained to get farmers understood the concept of cover crop growing, Furthermore, we make researches more profoundly on cover crops growing considering tree age, mixing rates among cover crops, seeding and cutting time for cover crops, and so on. Researchers, specialists of agricultural extensions, and farmers should concentrate their opinions and conduct IFP together. The IFP should go on systematically and reach finally to get certificates internationally by the International Organization for Biological and integrated Control of Noxious Animals and Plants(IOBC) to enhance selling and exporting fruits.

• The Journal of Korean Physical Therapy
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• 제18권2호
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• pp.35-45
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• 2006

Purpose: This study was to investigate the effect of isometric exercise and active stretching on joint function in patient with osteoarthritis. Methods: 30(M=1, F=29) subjects with osteoarthritis were divided in three groups: control group, quadriceps isometric exercise group, and hamstring active stretching group. After 6 weeks treatment, ROM(range of motion) and LSS(lysholm scoring scale) were measured. Results: There was a significant increase in knee flexion, extension in post-treat of quadriceps isometric exercise group and hamstring active stretching group(p<0.05). There was a significant increase in LSS in post-treat of quadriceps isometric exercise group and hamstring active stretching group(p<0.05). Conclusion: This study shows that both the active stretching exercise and the quadriceps isometric exercise effectively promote the range of knee extensions for osteoarthritis patients. Also, as measuring the ROM of knee flexion and extension by exercise methods, there is significant increase from knee flexion and extension in both hamstring stretching exercise group and quadriceps isometric exercise group. The increase of the range of knee is more effective in the exercise of knee extension with hamstring stretching exercise groups. And it is found that there are some difference between the experimental group and controlled group in statistics. As it is concerned with the function of knee extension, supporting and squatting are more effective to promote the both knee extension and flexion in its range. Therefore, this shows that the hamstring stretching exercise is required in general with enforcing the quadriceps at a sickbed in the present.

• 한국멀티미디어학회논문지
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• 제6권3호
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• pp.527-538
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• 2003

원격강의 컨텐츠는 강의 저작도구나 애니메이션 도구를 사용하여 저작된다. 저작된 컨텐츠는 미리 생성된 마디어들을 통합하고 교수자의 강의행동이 추가된 하나의 파일형태로 저장된다. 이 파일들은 각 저작도구에 따라 각기 다른 방식으로 저장되기 때문에 강의의 호환성이 없으며, 강의를 구성하는 미디어들의 다양한 활용 가능성이 떨어진다는 단점이 있다. 이러한 구조적 특성으로 인하여 온라인 환경에서 스트리밍 형태로 강의를 서비스 할 수 없는 제약을 갖는다. 본 논문에서는 멀티미디어 동기화 표현 언어인 SMIL을 이용하여 원격강의 컨텐츠의 호환성을 보장하는 기법을 제안하고자 한다. 제안하는 기법은 SMIL의 확장형태이며, 원격강의만의 특징인 교수자의 강의 행동을 표현하기 위한 태그들을 포함한다. 부가적으로 SMIL로 표현된 원격 강의 컨텐츠를 온라인 환경에서 스트리밍 하는 모델과 이를 위한 전송 제어 기법을 제시한다. 제안한 방식으로 구축된 원격강의 컨텐츠는 변환 모듈의 설치만으로 모든 원격강의 저자도구에 적용될 수 있으며, 온라인 환경에서의 스트리밍 서비스를 위한 동기화 정보의 표현 모델이 될 수 있다.

• 한국게임학회 논문지
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• 제10권4호
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• pp.63-71
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• 2010

본 논문에서는 증강현실 게임을 위하여 마커 영역을 이진화 할 수 있는 경계선 기반 마커 이진화 방법을 제안한다. 먼저, 경계선을 검출하기 위해 원 영상을 그레이 스케일 영상으로 변환한 뒤 경계선을 검출하고 마커영역의 경계선을 폐구간으로 만들기 위해 모든 경계선 화소에 대해서 4방향 확장 연산을 수행한다. 그리고 검출된 모든 경계선에 대해서 좌 우 화소의 명도를 비교하여 낮은 쪽에 검은색, 높은 쪽에 흰색을 할당하여 씨앗 영역 확장 기법을 통해 내부 영역을 채우면 마커영역의 이진화가 완료된다. 제안된 방법은 조명의 영향에 민감하지 않은 경계선 정보를 이용하여, 기존 단일 임계값을 사용한 이진화 방법에 비해 단계적 조명이나 그림자의 영향을 받은 영상에서도 마커 인식이 가능한 이진화 결과를 보였으며, VGA급 영상을 대상으로 평균 51fps의 처리속도를 보여 실시간 처리가 가능함을 알 수 있었다.