• Title/Summary/Keyword: inverse system

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Deep Learning-Based Inverse Design for Engineering Systems: A Study on Supervised and Unsupervised Learning Models

  • Seong-Sin Kim
    • International Journal of Internet, Broadcasting and Communication
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    • v.16 no.2
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    • pp.127-135
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    • 2024
  • Recent studies have shown that inverse design using deep learning has the potential to rapidly generate the optimal design that satisfies the target performance without the need for iterative optimization processes. Unlike traditional methods, deep learning allows the network to rapidly generate a large number of solution candidates for the same objective after a single training, and enables the generation of diverse designs tailored to the objectives of inverse design. These inverse design techniques are expected to significantly enhance the efficiency and innovation of design processes in various fields such as aerospace, biology, medical, and engineering. We analyzes inverse design models that are mainly utilized in the nano and chemical fields, and proposes inverse design models based on supervised and unsupervised learning that can be applied to the engineering system. It is expected to present the possibility of effectively applying inverse design methodologies to the design optimization problem in the field of engineering according to each specific objective.

Adaptive Inverse Feedback Control of Periodic Noise for Systems with Nonminimum Phase Cancellation Path (비최소위상 상쇄계를 가진 시스템을 위한 주기소음의 적응 역 궤환 제어)

  • Kim, Sun-Min;Park, Young-Jin
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.11
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    • pp.891-895
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    • 2001
  • An alternative inverse feedback structure for adaptive active control of periodic noise is introduced for systems with nonminimum phase cancellation path. To obtain the inverse model of the nonminimum phase cancellation path, the cancellation path model can be factorized into a minimum phase term and a maximum phase term. The maximum phase term containing unstable zeros makes the inverse model unstable. To avoid the instability, we alter the inverse model of the maximum phase system into an anti-causal FIR one. An LMS predictor estimates the future samples of the noise, which are necessary for causality of both anti-causal FIR approximation for the stable inverse of the maximum phase system and time-delay existing in the cancellation path. The proposed method has a faster convergence behavior and a better transient response than the conventional filtered-x LMS algorithms with the same internal model control structure since a filtered reference signal is not required. We compare the proposed methods with the conventional methods through simulation studies.

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CONDITION NUMBER FOR THE W- WEIGHTED DRAZIN INVERSE AND ITS APPLICATIONS IN THE SOLUTION OF RECTANGULAR LINEAR SYSTEM

  • CUI XIAOKE;DIAO HUAIAN
    • Journal of applied mathematics & informatics
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    • v.20 no.1_2
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    • pp.35-59
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    • 2006
  • In this paper, we generalized the results of [23, 26], and get the results of the condition number of the W-weighted Drazin-inverse solution of linear system W AW\chi=b, where A is an $m{\times}n$ rank-deficient matrix and the index of A W is $k_1$, the index of W A is $k_2$, b is a real vector of size n in the range of $(WA)^{k_2}$, $\chi$ is a real vector of size m in the range of $(AW)^{k_1}$. Let $\alpha$ and $\beta$ be two positive real numbers, when we consider the weighted Frobenius norm $\|[{\alpha}W\;AW,\;{\beta}b]\|$(equation omitted) on the data we get the formula of condition number of the W-weighted Drazin-inverse solution of linear system. For the normwise condition number, the sensitivity of the relative condition number itself is studied, and the componentwise perturbation is also investigated.

A Study on Inverse Kinematics Based Posture and Motion Generation System for Sports Climbing (역운동학 기반 스포츠클라이밍 자세 및 동작 생성 시스템에 관한 연구)

  • Shin, Kyucheol;Son, JongHee;Kim, Dongho
    • KIPS Transactions on Software and Data Engineering
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    • v.5 no.5
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    • pp.243-250
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    • 2016
  • Recently, public interest in virtual reality (VR) and augmented reality (AR) has increased. Therefore, computer graphics-related research has been actively conducted. This has included research on virtual space related to human posture implementation. However, such research has focused on general posture in humans. This paper presents a system with reference to the basic posture in sports climbing and the inverse kinematics method for generating the positions and behavior of virtual characteristics in a three-dimensional virtual space. The simulation based on the inverse kinematics method, produced with an inverse kinematics solver and initial pose animation from motion capture, provides realistic and natural movement. We designed a simulation system to generate correct posture and motions similar to those in sports climbing by applying the basic procedure of sports climbing. The simulation system provides help for producing content about sports climbing, such as learning programs for novice climbers and sports climbing games.

Target Marketing using Inverse Association Rule (역 연관규칙을 이용한 타겟 마케팅)

  • 황준현;김재련
    • Proceedings of the Korea Inteligent Information System Society Conference
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    • 2002.11a
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    • pp.241-249
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    • 2002
  • Making traditional plan of target marketing based on Association Rule has brought restriction to obtain the target of marketing. This paper is to present Inverse Association Rule as a new association rule for target marketing. Inverse Association Rule does not use information about relation between items that customers purchase like Association Rule, but use information about relation between items that customers do not pruchase. By adding Inverse Association Rule to target marketing, we generate new marketing rule to look for new target of marketing. From new marketing rule, this paper is to show direct marketing about target item and indirect marketing about another item associated with target item to sell target item. The reason is that sales of the item associated with target item have an influence on sales of target item.

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Evaluation of internal residual stresses in an elastic body by solving inverse problem (역문제 해석을 통한 탄성체 내부의 잔류응력 평가)

  • Lee, Sang-Hoon;Kim, Hyun-Gyu
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.597-602
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    • 2008
  • Most of structural analyses are concerned with the deformation and stress in a body subjected to external loads. In many fields, however, the interpretation of inverse problems is needed to determine surface tractions or internal stresses. In this study, the inverse processes by using the finite elements and the boundary elements are formulated for the evaluation of internal residual stresses from displacements measured on a remote surface. Small errors in the measured displacements often result in a substantial loss of accuracy of an inverse system. We use the Tikhonov regularization techniques to regularize the ill-conditioned system. Advantages and disadvantages are discussed through numerical examples.

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Inverse Dynamic Analysis of Flexible Multibody Systems with Closed-Loops

  • Lee, Byung-Hoon;Lee, Shi-Bok;Jeong, Weui-Bong;Yoo, Wan-Suk;Yang, Jin-Saeng
    • Journal of Mechanical Science and Technology
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    • v.15 no.6
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    • pp.693-698
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    • 2001
  • The analysis of actuating forces (or torques) and joint reaction forces (or moments) are essential to determine the capacity of actuators, to control the system and to design the components. This paper presents an inverse dynamic analysis algorithm for flexible multibody systems with closed-loops in the relative joint coordinate space. The joint reaction forces are analyzed in Cartesian coordinate space using the inverse velocity transformation technique. The joint coordinates and the deformation modal coordinates are used as the generalized coordinates of a flexible multibody system. The algorithm is verified through the analysis of a slider-crank mechanism.

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THE GENERALIZED INVERSE ${A_{T,*}}^{(2)}$ AND ITS APPLICATIONS

  • Cao, Chong-Guang;Zhang, Xian
    • Journal of applied mathematics & informatics
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    • v.11 no.1_2
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    • pp.155-164
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    • 2003
  • The existence and representations of some generalized inverses, including ${A_{T,*}}^{(2)},\;{A_{T,*}}^{(1,2)},\;{A_{T,*}}^{(2,3)},\;{A_{*,S}}^{(2)},\;{A_{*,S}}^{(1,2)}\;and\;{A_{*,S}}^{(2,4)}$, are showed. As applications, the perturbation theory for the generalized inverse {A_{T,S}}^{(2)} and the perturbation bound for unique solution of the general restricted system $A_{x}$ = b(dim(AT)=dimT, $b{\in}AT$ and $x{\in}T$) are studied. Moreover, a characterization and representation of the generalized inverse ${A_{T,*}}^{(2)}$ is obtained.

A Study on the Automatic Fairing and Modeling System of Hull From (선형의 자동순정 및 모델링 시스템에 관한 연구)

  • 김동준
    • Journal of Ocean Engineering and Technology
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    • v.14 no.2
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    • pp.121-127
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    • 2000
  • In this paper a new technique of inverse fairing problem for ship hull is proposed. Recently Lu solved the inverse fairing problem for automobile's body that was made by one surface element. In this system however hull surface is constructed by Gregory's composite surface interpolation method. So reflection line at boundary position is used as a tool of solving inverse problem in surface fairing. But the results are not good. The new concepts of Normal vector line and Constrained reflection line are introduced as an alternative tool. Energy minimization method for Normal Vector Line curve net and the inverse method for Constrained Reflection Line by using optimization technique are examined And the final lines from this proposed surface fairing method shows good fairness.

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An Implementation of Inverse Filter Using SVD for Multi-channel Sound Reproduction (SVD를 이용한 다중 채널상에서의 음재생을 위한 역변환 필터의 구현)

  • 이상권;노경래
    • The Journal of the Acoustical Society of Korea
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    • v.20 no.8
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    • pp.3-11
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    • 2001
  • This paper describes an implementation of inverse filter using SVD in order to recover the input in multi-channel system. The matrix formulation in SISO system is extended to MIMO system. In time and frequency domain we investigates the inversion of minimum phase system and non-minimum phase system. To execute an effective inversion of non-minimum phase system, SVD is introduced. First of all we computes singular values of system matrix and then investigates the phase property of system. In case of overall system is non-minimum phase, system matrix has one (or more) very small singular value (s). The very small singular value (s) carries information about phase properties of system. Using this property, approximate inverse filter of overall system is founded. The numerical simulation shows potentials in use of the inverse filter.

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