• Title/Summary/Keyword: systems-theory

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Knowledge Acquisition on Scheduling Heuristics Selection Using Dempster-Shafer Theory(DST) (Dempster-Shafer Theory를 이용한 스케듈링 휴리스틱선정 지식습득)

  • Han, Jae-Min;Hwang, In-Soo
    • Journal of Intelligence and Information Systems
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    • v.1 no.2
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    • pp.123-137
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    • 1995
  • Most of solution methods in scheduling attempt to generate good solutions by either developing algorithms or heuristic rules. However, scheduling problems in the real world require considering more factors such as multiple objectives, different combinations of heuristic rules due to problem characteristics. In this respect, the traditional mathematical a, pp.oach showed limited performance so that new a, pp.oaches need to be developed. Expert system is one of them. When an expert system is developed for scheduling one of the most difficult processes faced could be knowledge acquisition on scheduling heuristics. In this paper we propose a method for the acquisition of knowledge on the selection of scheduling heuristics using Dempster-Shafer Theory(DST). We also show the examples in the multi-objectives environment.

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Controller Design of Utility-connected Single-phase Inverter using d-q Theory (d-q이론을 이용한 개통 연계형 단상 인버터 제어기 설계기법)

  • Park, Chang-Joo;Kim, Chang-Hyun;Kim, Myung-Chul;Choi, Jae-Young
    • Proceedings of the KIEE Conference
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    • 2003.07b
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    • pp.1247-1249
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    • 2003
  • Despite many advantages, d-q theory was available only for three phase system. But recently, some papers proposed the application methods of d-a theory or similar theories for single phase systems. This paper presents the control method of the utility-connected single-phase inverter using d-q theory. The suggested method gives single-phase system instantaneous controllability and also makes the realization of APF(Active Power Filter) without DFT operation and PFC(Power Factor Controller) possible. This paper deals with utility-connected single phase inverter with PFC function. The controller was verified by simulation tool.

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A Study on Complementary Usage of System Dynamics and Theory of Constraints Approaches for Solving a Dilemma (갈등문제 해결을 위한 시스템다이내믹스와 제약이론 방법론의 상호 보완적 적용에 관한 연구)

  • Yee, Soung-Ryong
    • Korean System Dynamics Review
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    • v.12 no.4
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    • pp.63-92
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    • 2011
  • The purpose of this paper is to investigate a possibility of applying multimethodological approach for solving a dilemma. The motivation of this attempt is that the two different approaches, the system dynamics and the theory of constraints, resemble each other in having mental models for describing the target system and using graphic tools for representing those mental models. After a brief discussion on the comparison of the two approaches, a combined method applying to the problem of dilemma is suggested. For an experimental example, the proposed approach is applied to the sales and finance conflict on an inventory issue. The study shows that the suggested approach is able to complement each other's drawbacks. Especially constructing a stock-and-flow model and implementing a computer simulation would be very useful for quantifying the system's behavior which is hardly tracked down when applying the theory of constraints alone.

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Supplier Evaluation in Green Supply Chain: An Adaptive Weight D-S Theory Model Based on Fuzzy-Rough-Sets-AHP Method

  • Li, Lianhui;Xu, Guanying;Wang, Hongguang
    • Journal of Information Processing Systems
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    • v.15 no.3
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    • pp.655-669
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    • 2019
  • Supplier evaluation is of great significance in green supply chain management. Influenced by factors such as economic globalization, sustainable development, a holistic index framework is difficult to establish in green supply chain. Furthermore, the initial index values of candidate suppliers are often characterized by uncertainty and incompleteness and the index weight is variable. To solve these problems, an index framework is established after comprehensive consideration of the major factors. Then an adaptive weight D-S theory model is put forward, and a fuzzy-rough-sets-AHP method is proposed to solve the adaptive weight in the index framework. The case study and the comparison with TOPSIS show that the adaptive weight D-S theory model in this paper is feasible and effective.

Multi-Level Fusion Processing Algorithm for Complex Radar Signals Based on Evidence Theory

  • Tian, Runlan;Zhao, Rupeng;Wang, Xiaofeng
    • Journal of Information Processing Systems
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    • v.15 no.5
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    • pp.1243-1257
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    • 2019
  • As current algorithms unable to perform effective fusion processing of unknown complex radar signals lacking database, and the result is unstable, this paper presents a multi-level fusion processing algorithm for complex radar signals based on evidence theory as a solution to this problem. Specifically, the real-time database is initially established, accompanied by similarity model based on parameter type, and then similarity matrix is calculated. D-S evidence theory is subsequently applied to exercise fusion processing on the similarity of parameters concerning each signal and the trust value concerning target framework of each signal in order. The signals are ultimately combined and perfected. The results of simulation experiment reveal that the proposed algorithm can exert favorable effect on the fusion of unknown complex radar signals, with higher efficiency and less time, maintaining stable processing even of considerable samples.

Computerized responses of spinning NEMS via numerical and mathematical modeling

  • Zhou, Lingao
    • Structural Engineering and Mechanics
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    • v.82 no.5
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    • pp.629-641
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    • 2022
  • This study deals with the spinning impact on flap-wise vibration characteristics of nonlocal functionally graded (FG) cylindrical beam based on the Hyperbolic shear deformation beam theory. The nonlocal strain gradient theory is used to investigate the small-scale impact on the nonlocal motion equation as well as corresponding nonlocal boundary conditions. Based on the mathematical simulation and according to the Hamilton principle, the computerized modeling of a rotating functionally graded nanotube is generated, and then, via a numerical approach, the obtained mathematical equations are solved. The calculated outcomes are helpful to the production of Nano-electro-mechanical-systems (NEMS) by investigating some designed parameters such as rotating speed, hub radius, length-scale parameters, volume fraction parameters, etc.

On the dynamic stability of a composite beam via modified high-order theory

  • Man, Yi
    • Computers and Concrete
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    • v.30 no.2
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    • pp.151-164
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    • 2022
  • This paper investigates the stability of the functionally graded cylindrical small-scale tube regarding the dynamic analysis and based on the modified nonclassical high-order nonlocal strain gradient theory. The nonlocal beam is modeled according to the high-order tube theory utilizing the energy method based on the Hamilton principle, then the nonlocal governing equations and also nonlocal boundary conditions equations are obtained. The tube structure is made of the new class of composite material composed of ceramic and metal phases as the functionally graded structures. The functionally graded (FG) tube structures rotate around the central axis, and the stability of this nanodevice is due to the centrifugal force which is used for the application of nanoelectromechanical systems (NEMS) is studied in detail.

Research on Keyword-Overlap Similarity Algorithm Optimization in Short English Text Based on Lexical Chunk Theory

  • Na Li;Cheng Li;Honglie Zhang
    • Journal of Information Processing Systems
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    • v.19 no.5
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    • pp.631-640
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    • 2023
  • Short-text similarity calculation is one of the hot issues in natural language processing research. The conventional keyword-overlap similarity algorithms merely consider the lexical item information and neglect the effect of the word order. And some of its optimized algorithms combine the word order, but the weights are hard to be determined. In the paper, viewing the keyword-overlap similarity algorithm, the short English text similarity algorithm based on lexical chunk theory (LC-SETSA) is proposed, which introduces the lexical chunk theory existing in cognitive psychology category into the short English text similarity calculation for the first time. The lexical chunks are applied to segment short English texts, and the segmentation results demonstrate the semantic connotation and the fixed word order of the lexical chunks, and then the overlap similarity of the lexical chunks is calculated accordingly. Finally, the comparative experiments are carried out, and the experimental results prove that the proposed algorithm of the paper is feasible, stable, and effective to a large extent.

Research on Pattern Elements and Colors in Apparel Design through Fractal Theory

  • Dan Li;Chengjun Yuan
    • Journal of Information Processing Systems
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    • v.20 no.3
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    • pp.409-417
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    • 2024
  • Excellent apparel design can increase market competitiveness. This article briefly introduced the theory of fractals and its application in the field of apparel design. The convolutional neural network (CNN) algorithm was used to assist in the evaluation of apparel designs. In the case analysis, the accuracy of the evaluation was validated by comparing the CNN algorithm with two other intelligent algorithms, support vector machine (SVM) and back propagation (BP). The evaluation of the proposed design showed that compared with SVM and BP algorithms, the CNN algorithm had higher accuracy in evaluating apparel designs. The evaluation result of the proposed apparel design not only further verifies the effectiveness of the CNN algorithm, but also demonstrates that the theory of fractals can be effectively applied in apparel design to provide more innovative designs.

Forced vibration analysis of viscoelastic nanobeams embedded in an elastic medium

  • Akbas, Seref D.
    • Smart Structures and Systems
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    • v.18 no.6
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    • pp.1125-1143
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    • 2016
  • Forced vibration analysis of a simple supported viscoelastic nanobeam is studied based on modified couple stress theory (MCST). The nanobeam is excited by a transverse triangular force impulse modulated by a harmonic motion. The elastic medium is considered as Winkler-Pasternak elastic foundation.The damping effect is considered by using the Kelvin-Voigt viscoelastic model. The inclusion of an additional material parameter enables the new beam model to capture the size effect. The new non-classical beam model reduces to the classical beam model when the length scale parameter is set to zero. The considered problem is investigated within the Timoshenko beam theory by using finite element method. The effects of the transverse shear deformation and rotary inertia are included according to the Timoshenko beam theory. The obtained system of differential equations is reduced to a linear algebraic equation system and solved in the time domain by using Newmark average acceleration method. Numerical results are presented to investigate the influences the material length scale parameter, the parameter of the elastic medium and aspect ratio on the dynamic response of the nanobeam. Also, the difference between the classical beam theory (CBT) and modified couple stress theory is investigated for forced vibration responses of nanobeams.