• 한국전자파학회지:전자파기술
• /
• 제24권2호
• /
• pp.35-50
• /
• 2013

This paper discusses effects of mesh planes on signal integrity in high-speed glass ceramic packages. One of serious signal integrity issues in high-speed glass ceramic packages is high far-end (FE) noise coupling between signal interconnects. Based on signal integrity analysis, a methodology is presented for reducing far-end noise coupling between signal interconnects in high-speed glass ceramic modules. This methodology employing power/ground mesh planes with alternating spacing and a via-connected coplanar-type shield (VCS) structure is suggested to minimize far-end noise coupling between signal lines in high-speed glass ceramic packages. Optimized interconnect structure based on this methodology has demonstrated that the saturated far-end noise coupling of a typical interconnect structure in glass ceramic modules could be reduced significantly by 73.3 %.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2009년도 추계학술대회 논문집
• /
• pp.234-234
• /
• 2009

This paper illustrates the use of electric field computation to optimize the design of high voltage composite bushing. In the bushing, a high electric stress occurred between field shaper and central conductor by the closely space. Also coaxial cylindrical shield has a great height along the axis to control an electric field. Consequently, all the potentials are raised axially along the field shaper and electric stress is concentrated on a part of the surface of the FRP tube near the upper end of the field shaper. Maxwell 2D simulator based on the boundary element method was also introduced in order to verify the reliability of the polymer bushing. The optimized design uses internal elements for electric stress grading at critical parts of the bushing.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2010년도 춘계학술대회 논문집
• /
• pp.35-35
• /
• 2010

This paper illustrates the use of electric field computation to optimize the design of high voltage composite bushing. In the bushing, a high electric stress occurred between field shaper and central conductor by the closely space. Also coaxial cylindrical shield has a great height along the axis to control an electric field. Consequently, all the potentials are raised axially along the field shaper and electric stress is concentrated on a part of the surface of the FRP tube near the upper end of the field shaper. Maxwell 2D simulator based on the boundary element method was also introduced in order to verify the reliability of the polymer bushing. The optimized design uses internal elements for electric stress grading at critical parts of the bushing.

• Journal of Advanced Marine Engineering and Technology
• /
• 제35권2호
• /
• pp.258-263
• /
• 2011

본 연구는 국내 풍향 조건에 적합한 사보니우스 풍력 터빈의 개발과 효율향상을 위한 기초설계 자료를 얻고자 한다. 이를 위해 1/4 윈드실드가 부착된 풍력 터빈 주변의 유동장 특성을 수치해석으로 확인하였고, 터빈 로터의 회전수를 수치해석과 실험을 통하여 측정하였다. 측정결과 수치해석결과와 실험결과의 경향이 일치하였고, 윈드실드가 부착된 경우의 회전수가 약 70% 이상 향상됨을 확인하였다.

• 한국터널지하공간학회 논문집
• /
• 제19권5호
• /
• pp.799-812
• /
• 2017

쉴드 TBM 터널에 대한 2차원 수치해석 시 기존 연구에서는 뒤채움재 및 실제적인 내공변위 분포를 적절히 고려하지 않았다. 따라서 본 연구에서는 이를 보완하고자 gap parameter 적용 시 굴착면에서 발생하는 실제적인 내공변위분포를 고려하고, 적정한 뒤채움재 물성치를 적용한 모델링 방법을 제시하였다. 이를 위해 단일층 풍화토 지반을 대상으로 gap parameter와 토피고가 굴착면의 지반손실량과 지표손실량으로 구성되는 체적손실량에 미치는 영향을 분석하였다. 그 결과 대부분의 지표침하가 굴착 직후에 발생하였으며, 토피고 및 gap parameter가 증가할수록 수치해석을 통해 얻은 지표침하곡선의 영향범위가 제안된 이론식보다 넓게 나타났다. 따라서 2차원 수치해석 시 쉴드 TBM 터널의 거동을 정확히 평가하기 위해서는 하중분담률을 이용하여 gap parameter를 적용하고, 뒤채움재의 물성치도 적절히 고려해야 한다고 판단된다.

• 전기학회논문지
• /
• 제58권2호
• /
• pp.363-368
• /
• 2009

In the paper, we confirmed improvement Noise figure of the entire RF front-end using spiral inductor with PGS(Patterned Ground Shield) and current bleeding techniques. LNA design is to achieve simultaneous noise and input matching. Spiral inductor in input circuit of LNA inserted PGS for betterment of Q-factor. we modeling inductor using EM simulator, so compared with inductor of TSMC 0.18um. We designed and simulation the optimum structure of PGS using Taguchi's method. We confirmed enhancement of noise figure at LNA after substituted for inductor with PGS. Mixer designed using current bleeding techniques for reduced noise. We designed LNA using inductor with PGS and Mixer using current bleeding techniques, so confirmed improvement of noise figure.

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 1998년도 춘계학술발표회논문집(2)
• /
• pp.618-623
• /
• 1998

A shielding analysis was performed for the end shield of CANDU 6 reactor. The one-dimensional discrete ordinate code ANISN with a 38-group neutron-gamma library, extracted from DLC-37D library, was used to estimate the dose rate for the natural uranium CANDU reactor. For comparison MCNP-4B calculation was performed for the same system using continuous, discrete and multi-group libraries. The comparison has shown that the total dose rate of the ANISN calculation agrees well with that of the MCNP calculation. However, the individual dose rate (neutron and gamma) has shown opposite trends between AMISN and MCNP estimates, which may require a consistent library generation for both codes.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제50권3호
• /
• pp.101-106
• /
• 2001

Air-cored superconducting synchronous generator(ASSG) is characterized by an air-cored machine with its rotor iron and stator iron teeth removed. For this reason, in the case of the shape optimum design of ASSG, other design variables different from an iron-cored machine should be considered, which will lead to substantial improvement on the performance. The major design variables that are considered by using Three-dimensional Finite element Method(3D FEM) in this paper are : 1) field coil width, 2) axial length of magnetic shield, and 3) armature winding method. End-ring of armature winding is considered in the calculation of EMF. When it comes to field coil width, as field coil width enlarges, its effective field increases but the maximum field on the superconductor decreases. this determines the critical current density. this study presents an effective field coil width, axial length of magnetic shield, and armature winding method, and also the analysis is verified by the experimental results.

• 대한토목학회논문집
• /
• 제31권6D호
• /
• pp.839-848
• /
• 2011

TBM(Tunnel Boring Machine) 터널은 굴진 도중 장비의 교체나 개조 등은 불가능하기 때문에 굴진 종료 시까지 투입된 장비로 굴진하여야만 한다. 특히 토압식 쉴드TBM은 막장관찰이 어려우므로 굴진 중에 수집된 자료를 분석하여 지반상태의 변화를 예측하고 이를 시공에 반영하여야한다. 지금까지의 TBM에 대한 연구는 굴착 대상이 되는 지반의 특성에 따른 장비선정 및 굴진속도 예측모델 개발이 주로 이루어져왔다. 그러나 굴착의 주체가 되는 TBM 장비의 굴진자료에 의한 지반상태의 추정 및 운전방법의 개선에 초점을 맞춘 연구는 그리 많이 수행되지 않았다. 본 연구는 토압식 쉴드TBM 시공 사례에서 얻은 굴진자료를 활용하여 투입된 장비의 운전조건에 따른 굴진속도의 변화와 최적 운전조건에 대해 알아보았다. 본 연구의 결과를 요약하면 다음과 같다. 첫째, 커터헤드의 회전속도와 총추력이 굴진속도에 가장 큰 영향을 주며 둘째, 적정한 굴진속도를 위해서는 최적 회전속도를 유지하면서 총추력을 조정하는 것이 좋으며 셋째, 총추력의 증가 추세에 따라 지반조건의 변화에 대한 예측이 가능하여 이에 따라 적절한 운전조건의 변경을 결정할 수 있다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
• /
• pp.107-108
• /
• 2008

This article describes optimization for PGS(Patterned Ground Shield) of rectangular spiral inductor using Taguchi's Design of Experiment. PGS is decrease method of parasite component by silicon substrate among dielectric loss reduction method. Using taguchi's design of experiment, each parameter is fixed upon that PGS high poison(A), slot spacing(B), strip width(C) and overlap turn number(D) of PGS design parameter. Then we verified that percentage contribution and design sensitivity analysis of each parameter and level by signal to noise ratio of larger-the-better type. We consider percentage contribution and design sensitivity of each parameter and level, and then verify that model of optimization for PGS is lower inductance decreasing ratio and higher Q-factor increasing ratio by EM simulation.