• 한국공간구조학회:학술대회논문집
• /
• 한국공간구조학회 2008년도 춘계 학술발표회 논문집
• /
• pp.89-94
• /
• 2008

This paper deals with the method of self-equilibrium stress mode analysis of cable dome structures. From the point of view of analysis, cable dome structure is a kind of unstable truss structure which is stabilized by means of introduction of prestressing. The prestress must be introduced according to a specific proportion among different structural member and it is determined by an analysis called self-equilibrium stress mode analysis. The mathematical equation involved in the self-equilibrium stress mode analysis is a system of linear equations which can be solved numerically by adopting the concept of Moore-Penrose generalized inverse. The calculation of the generalized inverse is carried out by rank factorization method. This method involves a parameter called epsilon which plays a critical role in self-equilibrium stress mode analysis. It is thus of interest to investigate the range of epsilon which produces consistent solution during the analysis of self-equilibrium stress mode.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2009년도 제38회 동계학술대회 초록집
• /
• pp.314-314
• /
• 2010

The design of the blanket and shield play a key role in determining the size of a reactor since it has an impact on the various reactor components. The blanket should produce enough tritium for tritium self-sufficiency and the shield should provide sufficient protection for the superconducting TF coil. Neutronic optimization of the blanket and the shield is necessary, and we coupled the system analysis with a neutronic calculation to account for the interrelation of the blanket and shield with the plasma performance of a reactor system in a self-consistent manner. By using the coupled system analysis code, the operational space for a low aspect ratio (LAR) tokamak reactor with a superconducting toroidal field (TF) coil is investigated with an spect ratio in the range of 1.5 - 2.5. The minimum major radius which satisfies all the physics and engineering requirements increases with the magnetic field at the magnetic axis. A required inboard shield thickness is mainly determined by the requirement on the protection of the TF coil against radiation damage. It is shown that to have a fusion power bigger than 3,000 MW in the LAR tokamak with a superconducting TF coil, a major radius bigger than 4.0 m is required.

• Computers and Concrete
• /
• 제30권5호
• /
• pp.357-367
• /
• 2022

In this paper, we propose an efficient control method that can be transformed into a general building control problem for building structure control using these reliability criteria. To facilitate the calculation of controller H∞, an efficient solution method based on Linear Matrix Inequality (LMI) is introduced, namely H∞-based LMI control. In addition, a self-tuning predictive grey fuzzy controller is proposed to solve the problem caused by wrong parameter selection to eliminates the effect of dynamic coupling between degrees of freedom (DOF) in Self-Tuning Fuzzy Controllers. We prove stability using Lyapunov's stability theorem. To check the applicability of the proposed method, the proposed controller is applied and the control characteristics are determined. The simulation assumes system uncertainty in the controller design and emphasizes the use of acceleration feedback as a practical consideration. Simulation results show that the performance of the proposed controller is impressive, stable, and consistent with the performance of LMI-based methods. Therefore, an effective control method is suitable for seismic reinforcement of civil buildings.

• 대한전자공학회논문지
• /
• 제26권1호
• /
• pp.38-47
• /
• 1989

GaInAs/InP 이종접합(heterojunction)에서의 부밴드 구조(subband structure)를 self-consistent 방법으로구하였다. GaInAs내의 background impurity와 장벽높이 (barrier height 또는 밴드 불연속: band discontinuity)가 에너지 준위(energy level), 페르미 준위(Fermi level)와 점유율(population)등에 미치는 영향을 살펴보기 위하여, background impurity 농도의 경우 $1.0{\times}10^{14},\;1.0{\times}10^{15},\;1.0{\times}10^{16}\;[cm^{-3}]$, 장벽높이는 0.3, 0.53[eV]에 대하여 각각 살펴 보았다. Background impurity 농도가 증가함에 따라 에너지 값이 증가하며 페르미 준위 역시 증가한다. 아울러 첫번째와 두번째 에너지 준위의 차도 증가한다. 에너지 준위에 대한 전자의 점유율은 background impurity의 증가와 함께 큰 값을 나타내지만 두번째 에너지 준위에 대한 점유율은 거의 변하지 않는다. 장벽 높이가 커지면, 에너지 준위와 페르미 준위는 각각 증가하나 에너지 준위차는 거의 변화가 없다. 그런데, 장벽높이가 큰 경우 첫번째 에너지 준위에 대한 전자의 점유율은 ㄱ마소하는 반면 두번째 준위에 대한 점유율이 다소 증가한다.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
• /
• pp.526-526
• /
• 2012

DC magnetron discharges were studied using three-dimensional self-consistent particle-in-cell and Monte Carlo collisional (PIC-MCC) simulation codes. Two rectangular sputter sources (120 mm * 250 mm and 380 mm * 200 mm target sizes) were used in the simulation modeling. The number of incident ions to the Cu target as a function of position and simulation time was obtained. The target erosion profile was calculated by using the incident ions and the sputtering yields of the Cu target calculated with SRIM codes. The maximum ion density of the ion density distribution in the discharge was about $10^{10}cm^{-3}$ due to the calculation speed limit. The result may be less than one or two order of magnitude smaller than the real maximum ion density. However, the target erosion profiles of the two sputter sources were in good agreement with the measured target erosion profiles except for the erosion profile near the target surface, in which which the measured erosion width was broader than the simulation erosion width.

• 대한전자공학회논문지SD
• /
• 제42권3호
• /
• pp.9-16
• /
• 2005

[ $Si_{1-x}Ge_x$ ] 위의 Si 반전층에서의 이동도를 반전층에서의 양자현상(버금띠 에너지와 파동함수)과 완화시간어림셈을 고려하여 계산하였다. 반전층에서의 양자현상은 슈뢰딩거 방정식과 포아슨 방정식을 자체 모순없이 계산하여 얻었다 완화시간은 밸리내 산란과 밸리사이 산란을 고려하여 계산하였다. 그 결과 Ge 함량이 증가됨에 따라 이동도가 증가되는 이유는 4-폴드 밸리에 존재하는 전자의 이동도보다 2-폴드 밸리에 존재하는 전자의 이동도가 약 3배 정도 크며 대부분의 전자가 밸리의 분리에 의해 2-폴드 밸리에 존재하기 때문이라는 것을 알 수 있었다. 한편, 포논 산란만을 고려한 이동도를 실험치와 일치시키기 위하여 전체 이동도에는 반전층 계면에서의 산란과 쿨롱 산란을 포함시켰다. 계산된 전계, 온도, 그리고 Ge 함량에 의존하는 이동도는 실험치와 근접하도록 변형포텐셜을 설정하였으며 정확한 결과를 위해서는 Si 에너지띠의 비포물성을 고려해야함을 확인하였다.

• 한국전기전자재료학회논문지
• /
• 제18권9호
• /
• pp.781-786
• /
• 2005

The binding energy in the n-type $GaAs/Al_xGa_{1-x}As$ quantum well is calculated. The shooting method, modified from the finite difference method, is used for the calculation of the subband energy level and its wave function. In order to account tot the change of the potential energy due to the charged particles, impurities and electrons, the self consistent method is employed. The wave function used for the calculation of the binding energy is assumed to be composed of the envelope function and hydrogenic 1s function. Then, the binding energies calculated by taking into account lot two different types of the hydrogenic 1s function are compared.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
• /
• pp.582-582
• /
• 2012

Characteristics of a fusion-driven transmutation reactor was investigated. A compact reactor concept is desirable from an economic viewpoint. For the optimal design of a reactor, a radial build of reactor components has to be determined by considering the plasma physics and engineering constraints which inter-relate various reactor components. In a transmutation reactor, design of blanket and shield play a key role in determining the size of a reactor; the blanket should produce enough tritium for tritium self-sufficiency, the transmutation rate of waste has to be maximized, and the shield should provide sufficient protection for the superconducting toroidal field (TF) coil. To determine the radial build of the blanket and the shield, not only a radiation transport analysis but also a burnup calculation were coupled with the system analysis and it allowed the self-consistent determination of the design parameters of a transmutation reactor.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년도 추계학술대회 논문집 전기물성,응용부문
• /
• pp.158-159
• /
• 2006

The resistance-capacitance (RC) delay of signals through interconnection materials becomes a big hurdle for high speed operation of semiconductors which contain multilayer interconnection layers. In order to reduce the RC delay, low-k materials will be used for inter-metal dielectric (IMD) materials. We have developed self-consistent simulation tool that includes neutral-species transport model, based on the relaxation continuum (RCT) model. We present the parametric study of the modeling results of a two-frequency capacitively coupled plasma (2f-CCP) with $N_2/H_2$ gas mixture that is known as promising one for organic low-k materials etching. We include the neutral transport model as well as plasma one in the calculation. The plasma and neutrals are calculated self-consistently by iterating the simulation of both species till a spatiotemporal steady state profile could be obtained.

• Bulletin of the Korean Chemical Society
• /
• 제29권2호
• /
• pp.363-371
• /
• 2008

As a computational method for the discovery of the effective agonists for PPARd, we address the usefulness of molecular dynamics free energy (MDFE) simulation with explicit solvent in terms of the accuracy and the computing cost. For this purpose, we establish an efficient computational protocol of thermodynamic integration (TI) that is superior to free energy perturbation (FEP) method in parallel computing environment. Using this protocol, the relative binding affinities of GW501516 and its derivatives for PPARd are calculated. The accuracy of our protocol was evaluated in two steps. First, we devise a thermodynamic cycle to calculate the absolute and relative hydration free energies of test molecules. This allows a self-consistent check for the accuracy of the calculation protocol. Second, the calculated relative binding affinities of the selected ligands are compared with experimental IC50 values. The average deviation of the calculated binding free energies from the experimental results amounts at the most to 1 kcal/mol. The computational efficiency of current protocol is also assessed by comparing its execution times with those of the sequential version of the TI protocol. The results show that the calculation can be accelerated by 4 times when compared to the sequential run. Based on the calculations with the parallel computational protocol, a new potential agonist of GW501516 derivative is proposed.