• Kyungpook Mathematical Journal
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• 제64권2호
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• pp.205-218
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• 2024

Let 𝒜 be a Banach algebra. An element a ∈ 𝒜 has generalized Drazin inverse if there exists b ∈ 𝒜 such that b = bab, ab = ba, a - a²b ∈ 𝒜^qnil. New additive results for the generalized Drazin inverse of an operator over a Banach space are presented. we extend the main results of a paper of Shakoor, Yang and Ali from 2013 and of Wang, Huang and Chen from 2017. Appling these results to 2×2 operator matrices we also generalize results of a paper of Deng, Cvetković-Ilić and Wei from 2010.

• 한국전자통신학회논문지
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• 제9권8호
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• pp.867-873
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• 2014

유한체 연산에서 MONB를 사용하면 곱셈 역원 계산시에 대량의 제곱계산이 필요하므로 역원을 계산하는 데에 긴 시간이 필요하게 된다. 이에 본 논문에서는 바탕체 $GF(2^{2n})$ 위의 확대체 $GF(2^{2^nm})^*$에서 특수한 정규기저를 사용하여 역원을 구하는 저 비용의 알고리즘을 제안한다. 제안하는 알고리즘을 사용하면 곱셈 역원 계산에는 $nb(2^nm-1)+w(2^nm-1)-2$번의 곱셈과 $2^n-1$번의 제곱연산이 소요되며, H/W에서 구현한 결과 Itoh 등의 방법 보다 곱셈역원 계산속도가 빠르게 나타났다.

• 한국통신학회논문지
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• 제12권2호
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• pp.83-91
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• 1987

본 논문에서는 Chebyshev함수로 부터 확장된 inverse Chebyshev함수를 유도하였고, 통과대역 감쇠율 Ap(dB)=0.1, 0.2, 0.5, 1.0, 2.0, 3.0과 저지대역 주파수 Ws(rad/s)=1.2, 1.3, 1.4, 1.5, 1.6에 따른 n=5.6의 규순화된 2차식 계수값을 제시하였으며 그림3의 (c), (d)에서 보는 바와 같이 inverse Chebyshev 전달함수로부터 구한 저역통과필터는 통과대역에서 최대평탄도를, 저지대역에서 등파상을 가지는 크기 특성을 나타내었다. 또한 실제적인 회로 시뮬레이션을 통하여 크기와 손실 특성을 나타내고 그 소자치도 제시하였다.

• Structural Engineering and Mechanics
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• 제45권4호
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• pp.471-494
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• 2013

In this paper, identification of isotropic and orthotropic linear elastic material constitutive parameters has been demonstrated by a FEA-free energy-based inverse analysis method. An important feature of the proposed method is that it requires no finite element (FE) simulation of the tested material. Full-field displacements calculated using digital image correlation (DIC) are used to compute DIC stress fields enforcing the equilibrium condition and DIC strain fields using interpolation functions. Boundary tractions and displacements are implicitly recast into an objective function that measures the energy residual of external work and internal elastic strain energy. The energy conservation principle states that the residual should be zero, and so minimizing this objective function inversely identifies the constitutive parameters. Synthetic data from simulated testing of isotropic materials and orthotropic composite materials under 2D plane stress conditions are used for verification of the proposed method. When identifying the constitutive parameters, it is beneficial to apply loadings in multiple directions, and in ways that create non-uniform stress distributions. The sensitivity of the parameter identification method to noise in both the measured full-field DIC displacements and loadings has been investigated.

• Structural Engineering and Mechanics
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• 제28권5호
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• pp.525-548
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• 2008

This article deals the theory for solving an inverse problem of plate structures using the frequency-domain information instead of classical time-domain delays or free vibration eigenmodes or eigenvalues. A reduced set of output parameters characterizing the defect is used as a regularization technique to drastically overcome noise problems that appear in imaging techniques. A deconvolution scheme from an undamaged specimen overrides uncertainties about the input signal and other coherent noises. This approach provides the advantage that it is not necessary to visually identify the portion of the signal that contains the information about the defect. The theoretical model for Quantitative nondestructive evaluation, the relationship between the real and ideal models, the finite element method (FEM) for the forward problem, and inverse procedure for detecting the defects are developed. The theoretical formulation is experimentally verified using dynamic responses of a steel plate under impact loading at several points. The signal synthesized by FEM, the residual, and its components are analyzed for different choices of time window. The noise effects are taken into account in the inversion strategy by designing a filter for the cost functional to be minimized. The technique is focused toward a exible and rapid inspection of large areas, by recovering the position of the defect by means of a single accelerometer, overriding experimental calibration, and using a reduced number of impact events.

• 방송공학회논문지
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• 제16권5호
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• pp.782-792
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• 2011

In this paper, we address a new fast DCT-II/DFT/HWT hybrid transform architecture for digital video and fusion mobile handsets based on Jacket-like sparse matrix decomposition. This fast hybrid architecture is consist of source coding standard as MPEG-4, JPEG 2000 and digital filtering discrete Fourier transform, and has two operations: one is block-wise inverse Jacket matrix (BIJM) for DCT-II, and the other is element-wise inverse Jacket matrix (EIJM) for DFT/HWT. They have similar recursive computational fashion, which mean all of them can be decomposed to Kronecker products of an identity Hadamard matrix and a successively lower order sparse matrix. Based on this trait, we can develop a single chip of fast hybrid algorithm architecture for intelligent mobile handsets.

• 대한기계학회논문집A
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• 제33권11호
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• pp.1202-1208
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• 2009

An inverse finite element (FE) model parameter estimation algorithm can be used to characterize mechanical properties of biological tissues. Using this algorithm, we can consider the influence of material nonlinearity, contact mechanics, complex boundary conditions, and geometrical constraints in the modeling. In this study, biomechanical experiments on macro and micro samples are conducted and characterized with the developed algorithm. Macro scale experiments were performed to measure the force response of porcine livers against mechanical loadings using one-dimensional indentation device. The force response of the human liver cancer cells was also measured by the atomic force microscope (AFM). The mechanical behavior of porcine livers (macro) and human liver cancer cells (micro) were characterized with the algorithm via hyperelastic and linear viscoelastic models. The developed models are suitable for computing accurate reaction force on tools and deformation of biomechanical tissues.

• 한국인터넷방송통신학회논문지
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• 제16권1호
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• pp.15-20
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• 2016

공간다중화 방식을 사용하는 MIMO 시스템은 다이버시티 기법을 사용하는 MIMO 시스템과 비교할 때 높은 전송률을 달성하지만 다이버시티 이득이 낮아 데이터 전송 신뢰도를 높이기 위하여 MIMO 수신단에서 공간정보스트림을 분리해야한다. 본 논문에서는 격자부호에 의한 채널 용량 검출 기법, 사용자 3인인 간섭채널과 선형검출기법인 ZF(Zero Forcing)와 MMSE(Minimum Mean Square Error) 검파 기법을 비교했다. 이때 채널은 Diagonal 채널이 된다. 즉, Diagonal 채널은 $[H]_N[H]_N^{-1}=[I]_N$로 역행렬이 element-wise inverse로 Jacket 행렬의 성질을 만족함을 확인했다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.335.2-335
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• 2002

Non-singular boundary element method (BEM) codes are developed in acoustics application. The BEM code is then used to calculate unknown boundary surface normal displacements and surface pressures from known exterior near field pressures. And then the calculated surface normal displacements and surface pressures are again applied to the BEM in forward in order to calculate reconstructed field pressures. (omitted)

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.173-176
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• 2009

A great emphasis has been placed on the design of heat treatment process to achieve desired microstructure and mechanical property of final product. In this study, finite element analysis was carried out to predict temperature, microstructure and hardness of eutectoid steel after water quenching. Convective heat transfer coefficients were determined by inverse analysis using surface temperatures measured with three different installation methods of thermocouples. Finally, the effect of convective heat transfer coefficients on the prediction of temperature history and hardness was analyzed by comparing experimental and simulation results.