• Title/Summary/Keyword: T-matrix approach

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A linear program approach for optimizing a linear function over an efficient set (유효해집합 위에서의 최적화 문제를 위한 선형계획모델에 관한 연구)

  • Song, Jung-Hwan
    • Journal of Korean Institute of Industrial Engineers
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    • v.26 no.3
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    • pp.220-226
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    • 2000
  • The problem (P) of optimizing a linear function $d^Tx$ over the set of efficient points for a multiple objective linear program (M) is difficult because the efficient set is nonconvex. There are some interesting properties between the objective linear vector d and the matrix of multiple objectives C and those properties lead us to establish criteria to solve (P) with a linear program. In this paper we investigate a system of the linear equations $C^T{\alpha}$ = d and construct two linearly independent positive vectors u, v such that ${\alpha}$ = u - v. From those vectors u, v, solving an weighted sum linear program for finding an efficient extreme point for the (M) is a way of getting an optimal solution of the problem (P). Therefore the theorems presented in this paper provided us an easy way of solving nonconvex program (P) with a weighted sum linear program.

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Customer Satisfaction Measurement Using QFD in the College (QFD를 이용한 전문대학의 고객만족평가)

  • Woo, Tae-Hee
    • Journal of the Korea Safety Management & Science
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    • v.8 no.3
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    • pp.171-187
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    • 2006
  • Modern management considers customer satisfaction as a baseline standard of performance and a possible standard of excellence for any business organization including the college. Quality function deployment(QFD) is a structured approach to seek out voice of customers, understanding their needs, and ensure that their needs are met. The strategy value proposed by Chien et al. combines importance, satisfaction, performance, and ability to enhance decision making effectiveness. But in their model, the correlation among the strategic alternatives isn't considered the decision chain and is therefore eliminated. This paper proposes how to calculate the new weight of columns to consider various strength levels of correlations matrix, representing the correlation among the strategic alternatives, using normalization procedure. The aim of this paper is to present and original customer satisfaction survey conducted in the college. Thus, this paper presents an original customer satisfaction survey in the college and provides to demonstrate the practical usage of the design model to compare this model with Chien's model.

An improvement for system identification by use of M-transform

  • Kashiwagi, H.;Liu, M.;Harada, H.;Yamaguchi, T.
    • 제어로봇시스템학회:학술대회논문집
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    • 1998.10a
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    • pp.275-279
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    • 1998
  • In this paper, the authors propose a new method for improving identification method of linear system by us-ing M-transform. The authors has recently proposed a new mettled for linear system identification by use of M-transform. In this method, the input signal n(i) must have the same period N as that of the M-sequence. When N becomes large, it will take a long time to compute. To overcome this difficulty, we propose a new approach of system identification by using a small size matrix. The results of simulation show a good agreement with the theoretical considerations.

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The nonlinear fuzzy intelligent theory for high-bypass-ratio two-spool unmixed-flow jet engines

  • C.C. Hung;T. Nguyen
    • Advances in aircraft and spacecraft science
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    • v.10 no.4
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    • pp.369-391
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    • 2023
  • In our research we have offered a solid solution for aeronautical analysis. which can guarantee the asymptotic stability of coupled nonlinear facilities. According to the theoretical solutions and methods presented, the engine of this aircraft is a small high-bypass turbofan engine. using the non-linear aero-motor control approach and this paper focuses on the power management function of the aero-motor control system. These include static controls and transient controls. A mathematical model of the high-bypass-ratio two-spool unmixed-flow aeroengine was developed through a set of nonlinear dynamic equations verified by experimental data. A single actuator using the displacement method is designed to maintain a certain level of thrust under steady-state conditions. and maintains repeatable performance during transient operation from the requested thrust phase to the next. A single controller can compensate for the effects of noise and harmonic noise at many performance points. And the dynamic performance of a single controller is satisfactory during the transient. for fairness Numerical and computer experiments are described in the perfection of the methods we offer in research.

Development of an HVAC&R Systems Energy Evaluation Methodology and Simulation Program for Office Buildings (사무소 건물의 HVAC&R 시스템 에너지 분석방법 및 예측 프로그램 개발)

  • Cho, Jinkyun;Shin, Seungho;Kim, Jonghurn;Hwang, Dongkon;Hong, Hiki
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.25 no.7
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    • pp.363-370
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    • 2013
  • HVAC&R systems are the most energy consuming building services, representing approximately half of the final energy use in the building sector. Despite their significant energy use, there is a lack of a consistent and homogeneous framework to efficiently guide research. This research is about the energy consumptions of HVAC&R systems, with the aim of establishing a common idea for the analysis of building energy efficiency. Our approach deals with the concept of an HVAC&R set that is composed of subsystems. A matrix combination evaluation is examined, and a total of 960 sets can be implemented in a large scale office building. A method as a tool for energy evaluations of HVAC&R systems, and HEET as a energy simulation program, were developed.

Development of a highly effective T-DNA inserted mutant screening method in a Chinese cabbage (Brassica rapa L. spp. pekinensis) reverse genetics system

  • Lee, Gi-Ho;Kang, Yoon-Jee;Yi, Seul-Ki;Lim, Suk-Bin;Park, Young-Doo
    • Plant Biotechnology Reports
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    • v.4 no.3
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    • pp.201-211
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    • 2010
  • We present a highly effective T-DNA inserted gene screening method as part of a reverse genetics model system using the Chinese cabbage (Brassica rapa L. spp. pekinensis). Three-step two-dimensional (2D) matrix strategies are potentially accurate and useful for the identification of specific T-DNA inserted mutants from a large population. To construct our Chinese cabbage model, we utilized a forward genetics screening approach for the abnormal phenotypes that were obtained from transgenic plants of Brassica rapa generated with Agrobacteria tumefaciens containing the pRCV2 vector. From one transgenic plant with an abnormal phenotype, we observed that the st1 gene (which is related to senescence-associated process proteins) contained a T-DNA fragment, and that its expression level was decreased. This T-DNA insert was then used as a control to construct an effective screening pool. As a result, the optimum template concentration was found to be 0.1-1 ng in our PCR strategy. For other conditions, positive changes to the Gibbs free energy prevented the formation of oligo dimers and hairpin loop structures, and autosegment extension gave better results for long fragment amplification. Using this effective reverse genetics screening method, only 23 PCR reactions were necessary to select a target gene from a pool of 100 individual DNAs. Finally, we also confirmed that the sequence we obtained from the above method was identical to the flanking sequence isolated by rescue cloning.

An efficient hybrid TLBO-PSO-ANN for fast damage identification in steel beam structures using IGA

  • Khatir, S.;Khatir, T.;Boutchicha, D.;Le Thanh, C.;Tran-Ngoc, H.;Bui, T.Q.;Capozucca, R.;Abdel-Wahab, M.
    • Smart Structures and Systems
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    • v.25 no.5
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    • pp.605-617
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    • 2020
  • The existence of damages in structures causes changes in the physical properties by reducing the modal parameters. In this paper, we develop a two-stages approach based on normalized Modal Strain Energy Damage Indicator (nMSEDI) for quick applications to predict the location of damage. A two-dimensional IsoGeometric Analysis (2D-IGA), Machine Learning Algorithm (MLA) and optimization techniques are combined to create a new tool. In the first stage, we introduce a modified damage identification technique based on frequencies using nMSEDI to locate the potential of damaged elements. In the second stage, after eliminating the healthy elements, the damage index values from nMSEDI are considered as input in the damage quantification algorithm. The hybrid of Teaching-Learning-Based Optimization (TLBO) with Artificial Neural Network (ANN) and Particle Swarm Optimization (PSO) are used along with nMSEDI. The objective of TLBO is to estimate the parameters of PSO-ANN to find a good training based on actual damage and estimated damage. The IGA model is updated using experimental results based on stiffness and mass matrix using the difference between calculated and measured frequencies as objective function. The feasibility and efficiency of nMSEDI-PSO-ANN after finding the best parameters by TLBO are demonstrated through the comparison with nMSEDI-IGA for different scenarios. The result of the analyses indicates that the proposed approach can be used to determine correctly the severity of damage in beam structures.

Behavior of H-Type Steel Pile Under Axial Lond in Cohesionless Soils (사질토 지반에서 H-형 강말뚝의 축방향 거동)

  • Hong Sa-Myun;Lee Yeong-Saeng
    • Journal of the Korean Geotechnical Society
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    • v.21 no.8
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    • pp.5-12
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    • 2005
  • In early days, to analyze the behavior of single pile under axial load, many assumptions were made and field tests were performed. But in recent days, the development of computers led the use of the numerical analysis resulting in more realistic and correct results. The numerical methods are classified into Load Transfer Method and Elastic Solid Approach. In this study a numerical program applying t-z model to Load Transfer Method suggested by Coyle & Reese was developed. And another finite difference program using matrix based on this load transfer was developed. As a result, it is found that the values of the F.D.M. were similar to the values measured in-situ.

Structural identification based on substructural technique and using generalized BPFs and GA

  • Ghaffarzadeh, Hosein;Yang, T.Y.;Ajorloo, Yaser Hosseini
    • Structural Engineering and Mechanics
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    • v.67 no.4
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    • pp.359-368
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    • 2018
  • In this paper, a method is presented to identify the physical and modal parameters of multistory shear building based on substructural technique using block pulse generalized operational matrix and genetic algorithm. The substructure approach divides a complete structure into several substructures in order to significantly reduce the number of unknown parameters for each substructure so that identification processes can be independently conducted on each substructure. Block pulse functions are set of orthogonal functions that have been used in recent years as useful tools in signal characterization. Assuming that the input-outputs data of the system are known, their original BP coefficients can be calculated using numerical method. By using generalized BP operational matrices, substructural dynamic vibration equations can be converted into algebraic equations and based on BP coefficient for each story can be estimated. A cost function can be defined for each story based on original and estimated BP coefficients and physical parameters such as mass, stiffness and damping can be obtained by minimizing cost functions with genetic algorithm. Then, the modal parameters can be computed based on physical parameters. This method does not require that all floors are equipped with sensor simultaneously. To prove the validity, numerical simulation of a shear building excited by two different normally distributed random signals is presented. To evaluate the noise effect, measurement random white noise is added to the noise-free structural responses. The results reveal the proposed method can be beneficial in structural identification with less computational expenses and high accuracy.

Topic Model Augmentation and Extension Method using LDA and BERTopic (LDA와 BERTopic을 이용한 토픽모델링의 증강과 확장 기법 연구)

  • Kim, SeonWook;Yang, Kiduk
    • Journal of the Korean Society for information Management
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    • v.39 no.3
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    • pp.99-132
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    • 2022
  • The purpose of this study is to propose AET (Augmented and Extended Topics), a novel method of synthesizing both LDA and BERTopic results, and to analyze the recently published LIS articles as an experimental approach. To achieve the purpose of this study, 55,442 abstracts from 85 LIS journals within the WoS database, which spans from January 2001 to October 2021, were analyzed. AET first constructs a WORD2VEC-based cosine similarity matrix between LDA and BERTopic results, extracts AT (Augmented Topics) by repeating the matrix reordering and segmentation procedures as long as their semantic relations are still valid, and finally determines ET (Extended Topics) by removing any LDA related residual subtopics from the matrix and ordering the rest of them by F1 (BERTopic topic size rank, Inverse cosine similarity rank). AET, by comparing with the baseline LDA result, shows that AT has effectively concretized the original LDA topic model and ET has discovered new meaningful topics that LDA didn't. When it comes to the qualitative performance evaluation, AT performs better than LDA while ET shows similar performances except in a few cases.