• Title/Summary/Keyword: approximate inverse

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Approximation of Green Warranty Function by Radon Radial Basis Function Network (Radon RBF Network에 의해 그린 보증 함수의 근사화)

  • Lee, Sang-Hyun;Lim, Jong-Han;Moon, Kyung-Li
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.3
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    • pp.123-131
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    • 2012
  • As the price of traditional fuels soar, the alternatives are becoming more viable. And manufacturers are promoting the growing viability of electric and biofuel-powered vehicles through longer warranties. Now, these longer green environment (emission)warranties, sometimes called extended warranties or "super warranties," have been adapted. The main result of this paper is to present a new method to approximate a bivariate warranty function by using Radial Basis Function Network with application of Radon Transform and its inverse which is used to reduce the dimension of the warranty space. This method consist of the following stages: First, by using the Radon Transform, the bivariate warranty function can be reduced to one dimensional function. Second, each of the one dimensional functions is approximated by using neural network technique into neural sub-networks. Third, these neural sub-networks are combined together to form the final approximation neural network. Four, by using the inverse of radon transform to this final approximation neural network we get the approximation to the given function. Also, we apply the above method to some green warranty data of automotive vehicle company.

Real-Time Lane Detection Based on Inverse Perspective Transform and Search Range Prediction (역원근 변환과 검색 영역 예측에 의한 실시간 차선 인식)

  • Kim, S.H.;Lee, D.H.;Lee, M.H.;Be, J.I.
    • Proceedings of the KIEE Conference
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    • 2000.07d
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    • pp.2843-2845
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    • 2000
  • A lane detection based on a road model or feature all need correct acquirement of information on the lane in a image, It is inefficient to implement a lane detection algorithm through the full range of a image when being applied to a real road in real time because of the calculating time. This paper defines two searching range of detecting lane in a road, First is searching mode that is searching the lane without any prior information of a road, Second is recognition mode, which is able to reduce the size and change the position of a searching range by predicting the position of a lane through the acquired information in a previous frame. It is allow to extract accurately and efficiently the edge candidates points of a lane as not conducting an unnecessary searching. By means of removing the perspective effect of the edge candidate points which are acquired by using the inverse perspective transformation, we transform the edge candidate information in the Image Coordinate System(ICS) into the plane-view image in the World Coordinate System(WCS). We define linear approximation filter and remove the fault edge candidate points by using it This paper aims to approximate more correctly the lane of an actual road by applying the least-mean square method with the fault-removed edge information for curve fitting.

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Cross-Validation of SPT-N Values in Pohang Ground Using Geostatistics and Surface Wave Multi-Channel Analysis (지구통계기법과 표면파 다중채널분석을 이용한 포항 지반의 SPT-N value 교차검증)

  • Kim, Kyung-Oh;Han, Heui-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.10
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    • pp.393-405
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    • 2020
  • Various geotechnical information is required to evaluate the stability of the ground and a foundation once liquefaction occurs due to earthquakes, such as the soil strength and groundwater level. The results of the Standard Penetration Test (SPT) conducted in Korea are registered in the National Geotechnical Information Portal System. If geotechnical information for a non-drilled area is needed, geostatistics can be applied. This paper is about the feasibility of obtaining ground information by the Empirical Bayesian Kriging (EBK) method and the Inverse Distance Weighting Method (IDWM). Esri's ArcGIS Pro program was used to estimate these techniques. The soil strength parameter of the drilling area and the level of groundwater obtained from the standard penetration test were cross-validated with the results of the analysis technique. In addition, Multichannel Analysis of Surface Waves (MASW) was conducted to verify the techniques used in the analysis. The Buk-gu area of Pohang was divided into 1.0 km×1.0 km and 110 zones. The cross-validation for the SPT N value and groundwater level through EBK and IDWM showed that both techniques were suitable. MASW presented an approximate section area, making it difficult to clearly grasp the distribution pattern and groundwater level of the SPT N value.

Regeneration of the Retarded Time Vector for Enhancing the Precision of Acoustic Pyrometry (온도장 측정 정밀도 향상을 위한 시간 지연 벡터의 재형성)

  • Kim, Tae-Kyoon;Ih, Jeong-Guon
    • The Journal of the Acoustical Society of Korea
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    • v.33 no.2
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    • pp.118-125
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    • 2014
  • An approximation of speed of sound in the measurement plane is essential for the inverse estimation of temperature. To this end, an inverse problem relating the measured retarded time data in between set of sensors and actuators array located on the wall is formulated. The involved transfer matrix and its coefficient vectors approximate speed of sound of the measurement plane by using the radial basis function with finite number of interpolation points deployed inside the target field. Then, the temperature field can be reconstructed by using spatial interpolation technique, which can achieve high spatial resolution with proper number of interpolation points. A large number of retarded time data of acoustic paths in between sensors and arrays are needed to obtain accurate reconstruction result. However, the shortage of interpolation points due to practical limitations can cause the decrease of spatial resolution and deterioration of the reconstruction result. In this works, a regeneration for obtaining the additional retarded time data for an arbitrary acoustic path is suggested to overcome the shortage of interpolation points. By applying the regeneration technique, many interpolation points can be deployed inside the field by increasing the number of retarded time data. As a simulation example, two rectangular duct sections having arbitrary temperature distribution are reconstructed by two different data set: measured data only, combination of measured and regenerated data. The result shows a decrease in reconstruction error by 15 % by combining the original and regenerated retarded time data.

Neural-based Blind Modeling of Mini-mill ASC Crown

  • Lee, Gang-Hwa;Lee, Dong-Il;Lee, Seung-Joon;Lee, Suk-Gyu;Kim, Shin-Il;Park, Hae-Doo;Park, Seung-Gap
    • Journal of the Korean Institute of Intelligent Systems
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    • v.12 no.6
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    • pp.577-582
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    • 2002
  • Neural network can be trained to approximate an arbitrary nonlinear function of multivariate data like the mini-mill crown values in Automatic Shape Control. The trained weights of neural network can evaluate or generalize the process data outside the training vectors. Sometimes, the blind modeling of the process data is necessary to compare with the scattered analytical model of mini-mill process in isolated electro-mechanical forms. To come up with a viable model, we propose the blind neural-based range-division domain-clustering piecewise-linear modeling scheme. The basic ideas are: 1) dividing the range of target data, 2) clustering the corresponding input space vectors, 3)training the neural network with clustered prototypes to smooth out the convergence and 4) solving the resulting matrix equations with a pseudo-inverse to alleviate the ill-conditioning problem. The simulation results support the effectiveness of the proposed scheme and it opens a new way to the data analysis technique. By the comparison with the statistical regression, it is evident that the proposed scheme obtains better modeling error uniformity and reduces the magnitudes of errors considerably. Approximatly 10-fold better performance results.

A Robust Preconditioner on the CRAY-T3E for Large Nonsymmetric Sparse Linear Systems

  • Ma, Sangback;Cho, Jaeyoung
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.5 no.1
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    • pp.85-100
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    • 2001
  • In this paper we propose a block-type parallel preconditioner for solving large sparse nonsymmetric linear systems, which we expect to be scalable. It is Multi-Color Block SOR preconditioner, combined with direct sparse matrix solver. For the Laplacian matrix the SOR method is known to have a nondeteriorating rate of convergence when used with Multi-Color ordering. Since most of the time is spent on the diagonal inversion, which is done on each processor, we expect it to be a good scalable preconditioner. Finally, due to the blocking effect, it will be effective for ill-conditioned problems. We compared it with four other preconditioners, which are ILU(0)-wavefront ordering, ILU(0)-Multi-Color ordering, SPAI(SParse Approximate Inverse), and SSOR preconditioner. Experiments were conducted for the Finite Difference discretizations of two problems with various meshsizes varying up to 1024 x 1024, and for an ill-conditioned matrix from the shell problem from the Harwell-Boeing collection. CRAY-T3E with 128 nodes was used. MPI library was used for interprocess communications. The results show that Multi-Color Block SOR and ILU(0) with Multi-Color ordering give the best performances for the finite difference matrices and for the shell problem only the Multi-Color Block SOR converges.

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High Resolution ISAR Imaging Based on Improved Smoothed L0 Norm Recovery Algorithm

  • Feng, Junjie;Zhang, Gong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.12
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    • pp.5103-5115
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    • 2015
  • In radar imaging, a target is usually consisted of a few strong scatterers which are sparsely distributed. In this paper, an improved sparse signal recovery algorithm based on smoothed l0 (SL0) norm method is proposed to achieve high resolution ISAR imaging with limited pulse numbers. Firstly, one new smoothed function is proposed to approximate the l0 norm to measure the sparsity. Then a single loop step is used instead of two loop layers in SL0 method which increases the searching density of variable parameter to ensure the recovery accuracy without increasing computation amount, the cost function is undated in every loop for the next loop until the termination is satisfied. Finally, the new set of solution is projected into the feasible set. Simulation results show that the proposed algorithm is superior to the several popular methods both in terms of the reconstruction performance and computation time. Real data ISAR imaging obtained by the proposed algorithm is competitive to several other methods.

Ruin Probability on Insurance Risk Models (보험위험 확률모형에서의 파산확률)

  • Park, Hyun-Suk;Choi, Jeong-Kyu
    • The Korean Journal of Applied Statistics
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    • v.24 no.4
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    • pp.575-586
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    • 2011
  • In this paper, we study an asymptotic behavior of the finite-time ruin probability of the compound Poisson model in the case that the initial surplus is large. To compare an exact ruin probability with an approximate one, we place the focus on the exact calculation for the ruin probability when the claim size distribution is regularly varying tailed (i.e. exponential claims and inverse Gaussian claims). We estimate an adjustment coefficient in these examples and show the relationship between the adjustment coefficient and the safety premium. The illustration study shows that as the safety premium increases so does the adjustment coefficient. Larger safety premium means lower "long-term risk", which only stands to reason since higher safety premium means a faster rate of safety premium income to offset claims.

A Fault Detection System Design for Boiler-Turbine Control System of Thermal Power Pant (화력발전소 보일러-터빈 제어시스템의 고장검출시스템 설계)

  • Yoo, Seog-Hwan
    • Journal of the Korean Institute of Intelligent Systems
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    • v.25 no.6
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    • pp.615-620
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    • 2015
  • This paper deals with a fault detection system design for a boiler-turbine control system of thermal power plant. We described the nonlinear properties of the boiler-turbine dynamics as a T-S fuzzy system with time varying measurable parameters. We design a residual generator using an observer based fault detection filter. In order to identify the faulted output sensor, an approximate inverse system is connected to the outport of the fault detection filter. We demonstrate the efficiency of the suggested design method via computer simulations.

Strength Demand Calculation for Retrofitting Unreinforced Masonry Buildings Based on the Displacement Coefficient Method and the Preliminary Seismic Evaluation Procedure (변위계수법 및 약산식 내진성능평가에 기초한 비보강 조적조 건물의 내진보강 요구강도 산정)

  • Seol, Yun Jeong;Park, Ji-Hun;Kwak, Byeong Hun;Kim, Dae Ho
    • Journal of the Earthquake Engineering Society of Korea
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    • v.26 no.1
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    • pp.31-38
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    • 2022
  • Based on the nonlinear static analysis and the approximate seismic evaluation method adopted in "Guidelines for seismic performance evaluation for existing buildings, two methods to calculate strength demand for retrofitting individual structural walls in unreinforced masonry buildings are proposed." The displacement coefficient method to determine displacement demand from nonlinear static analysis results is used for the inverse calculation of overall strength demand required to reduce the displacement demand to a target value meeting the performance objective of the unreinforced masonry building to retrofit. A preliminary seismic evaluation method to screen out vulnerable buildings, of which detailed evaluation is necessary, is utilized to calculate overall strength demand without structural analysis based on the difference between the seismic demand and capacity. A system modification factor is introduced to the preliminary seismic evaluation method to reduce the strength demand considering inelastic deformation. The overall strength demand is distributed to the structural walls to retrofit based on the wall stiffness, including the remaining walls or otherwise. Four detached residential houses are modeled and analyzed using the nonlinear static and preliminary evaluation procedures to examine the proposed method.