• Steel and Composite Structures
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• 제20권2호
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• pp.295-316
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• 2016

This paper presents the results of experimental investigation, numerical calculation and theoretical analysis on axial compression ratio limit values for steel reinforced concrete (SRC) special shaped columns. 17 specimens were firstly intensively carried out to investigate the hysteretic behavior of SRC special shaped columns subjected to a constant axial load and cyclic reversed loads. Two theories were used to calculate the limits of axial compression ratio for all the specimens, including the balanced failure theory and superposition theory. It was found that the results of balanced failure theory by numerical integration method cannot conform the reality of test results, while the calculation results by employing the superposition theory can agree well with the test results. On the basis of superposition theory, the design limit values of axial compression ratio under different seismic grades were proposed for SRC special shaped columns.

• International Journal of Precision Engineering and Manufacturing
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• 제4권2호
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• pp.5-12
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• 2003

This study presents a solution to control a PMSM without sensors. The control method is the presented superposition principle. This method of sensorless theory is very simple to compute estimated angle. Therefore, computing time to estimate angle is shorter than other sensorless methods. The use of this system yields enhanced operations, fewer system components, lower system costs, efficient energy control system designs and increased efficiencies. A practical solution is described and its results are given in this study. The performance of a sensorless architecture allows an intelligent approach to reduce the complete system costs of digital motion control applications using the cheaper electrical sensorless motors. This paper deals with an overview of solutions in the sensorless PHSM control applications, whereby the focus will be the new sensorless controller and its applications.

• Bulletin of the Korean Chemical Society
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• 제30권4호
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• pp.794-796
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• 2009

We have studied the structures and stabilities of Au6 to explore the origin of the large discrepancy between relative energies obtained from the density functional theory (DFT) and ab initio correlated levels of theory. The MP2 methods significantly overestimate the stability of the non-planar isomer when the double-$\zeta$ polarization quality of basis sets, such as LANL2DZ+1f and CEP31G+1f, are used. However, we show that such preference for the non-planar structure at the MP2 level mainly originates from the large basis set superposition error.

• 제어로봇시스템학회논문지
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• 제8권1호
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• pp.5-14
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• 2002

This study presents a solution to control a Permanent Magnet Synchronous Motor without sensors based on the superposition principle. Because the proposed method of sensorless theory is very simple to compute the estimated angle, computing time to estimate the angle is shorter than other sensorless method. The use of this system yields enhanced operations, fewer system components, lower system cost, energy efficient control system design and increased efficiency. The performance of a sensorless architecture allows an intelligent approach to reduce the complete system costs of the digital motion control applications using cheaper electrical motors without sensors. This paper deals with an overview of sensorless solutions in PMSM control applications whereby the focus will be on the new controller without sensors and its applications.

• Computers and Concrete
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• 제16권6호
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• pp.897-908
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• 2015

This article gives analytical dependences for creep of concrete at heating, taking into account conditions of its drying. These dependences are based on the standard nonlinear theory of creep of concrete at a normal temperature and temperature-time analogy. For the description of creep at various stresses and temperatures the principle of superposition are used. All stages of model's creation are confirmed by the existing experimental data. Calculation examples are given.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.756-760
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• 2002

This study presents a solution to control a Permanent Magnet Synchronous Motor without sensors. The control method is the presented superposition principle. This method of sensorless theory is very simple to compute estimated angle. Therefore computing time to estimate angle is shorter than other sensorless method. The use of this system yields enhanced operations, fewer system components, lower system cost, energy efficient control system design and increased efficiency. A practical solution is described and results are given in this Study. The performance of a Sensorless architecture allows an intelligent approach to reduce the complete system costs of digital motion control applications using cheaper electrical motors without sensors. This paper deals with an overview of sensorless solutions in PMSM control applications whereby the focus will be the new Controller without sensors and its applications.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 학술대회 논문집 전문대학교육위원
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• pp.120-126
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• 2001

This paper presents a solution to control a PMSM(Permanent Magnet Synchronous Motor) without sensor. The control method is the presented superposition principle. This method of sensorless theory is very simple to compute estimated angle. The use of this system yields enhanced operations, fewer system components, lower system costs, efficient energy control system designs and increased efficiencies. A practical solution is described and its results are given in this study. The performance of a sensorless architecture allows an intelligent approach to reduce the complete system costs of digital motion control applications using the cheaper electrical sensorless motors. This paper deals with an overview of solutions in the sensorless PMSM control applications, whereby the focus will be the new sensorless controller and its applications.

• Geomechanics and Engineering
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• 제15권5호
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• pp.1029-1038
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• 2018

A superposition-iteration (S-I) model is proposed to simulate the jet grouting pre-reinforcing impact for a shallow-buried tunnel. The common model is deduced by theoretical (force equilibrium) analysis and then transformed into the numerical formulation. After applying it to an actual engineering problem, the most obvious deficiency was found to be continuous error accumulation, even when the parameters change slightly. In order to address this problem, a superposition-iteration model is developed based on the basic assumption and superposition theory. First, the additional deflection between two successive excavation steps is determined. This is caused by the disappearance of the supporting force in the excavated zone and the soil pressure in the disturbed zone. Consequently, the final deflection can be obtained by repeatedly superposing the additional deflection to the initial deflection in the previous steps. The analytical solution is then determined with the boundary conditions. The superposition-iteration model is thus established. This model was then applied and found to be suitable for real-life engineering applications. During the calculation, the error induced by the ill-conditioned problem of the matrix is easily addressed. The precision of this model is greater compared to previous models. The sensitivity factors and their impact are determined through this superposition-iteration model.

• 화약ㆍ발파
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• 제26권1호
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• pp.15-21
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• 2008

건물해체에서 발생하는 충격진동의 예측은 구조물의 낙하높이와 중량, 즉 위치에너지가 고려되어져왔다. 본 연구에서는 충격진동의 예측방법으로써, 위치에너지 대신 낙하중량에 관한 충격량을 이용한 새로운 식을 제시하였다. 실험은 자유낙하를 통해 기존의 방법인 위치에너지와 본 연구에서 제시하는 충격량을 회귀분석 결과로 비교 분석하였다. 또한 중첩원리를 이용한 방법도, 즉 거리별 감쇠율, 높이별 자유낙하시차, 붕괴패턴에 따른 지반에 충격을 가하는 시점을 산정함으로써, 기존 건물해체 진동데이터와 동일 조건에서 비교해 보았다. 결론적으로 본 연구에서는, 기존의 충격진동을 예측하는 방법으로써 충격량과 중첩의 원리를 이용한 새로운 방법이 적용되어야 함을 제안하였다. 이러한 결과는 실제 건물해체 시 발생하는 충격진동을 기존의 방법보다 정확하게 예측할 수 있을 거라고 기대할 수 있다.

• 대한조선학회논문집
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• 제55권4호
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• pp.281-288
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• 2018

Acoustic radiation efficiency is a crucial factor to estimate Underwater Radiated Noise (URN) of ships accurately. This paper describes a numerical method to analyse acoustic radiation efficiency of one side-wetted rectangular Mindlin plate with simply supported boundaries excited by a harmonic point force. Transverse displacements of plate and acoustic radiation pressures are evaluated by the mode superposition method. The acoustic radiation efficiencies analyzed by both Mindlin and thin plate theories show little differences at monopole and corner modes of low frequency regions but relatively large differences at edge and critical modes of high frequency regions. Especially, the critical frequency with the highest acoustic radiation efficiency evaluated by the Mindlin plate theory is higher than that of thin plate theory. In addition, the acoustic loading effect of fluid also increases bending wave-number of plate and its critical frequency. Finally, the acoustic radiation characteristics of plates with different aspect ratios and thicknesses through numerical analyses are investigated and discussed.