• Title/Summary/Keyword: Computer structure analysis

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The Psychometric Properties of Distance-Digital Subjective Happiness Scale

  • Almaleki, Deyab A.
    • International Journal of Computer Science & Network Security
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    • v.21 no.5
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    • pp.211-216
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    • 2021
  • This study intended to test the structure of the latent factor of a subjective happiness scale and the stability of invariance across groups of students' classifications (gender and students' status). In the large, non-clinical sample (619), students completed the subjective happiness scale. The (CFA) confirmatory factor analysis was used to investigate the factor-structure of the measure, and multiple-group confirmatory factor analysis (MGCFA) model was used to test the stability of invariance across groups of students classifications. The findings of the CFA indicated support for the original one-factor model. Additional analyses of the MGCFA method support the measurement (configural, metric and strong) invariant and practical invariant components of this model. There was an invariant across gender. There was partially invariant across groups of students' statuses. The scale exists in both groups to assess the same concepts of (single and married), excluding Items 3 and 4. Given that this study is the first investigation for the structure of the subjective happiness scale.

The Psychometric Properties of Effectiveness Scale in Distance-Digital

  • Almaleki, Deyab A.
    • International Journal of Computer Science & Network Security
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    • v.21 no.12
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    • pp.149-156
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    • 2021
  • This study intended to test the structure of the latent factor of an effectiveness scale and the stability of invariance across groups of students' classifications (gender and levels of education). In the large, non-clinical sample (850), students completed the effectiveness scale. The (CFA) confirmatory factor analysis was used to investigate the factor-structure of the measure, and multiple-group confirmatory factor analysis (MGCFA) model was used to test the stability of invariance across groups of students' classifications. The findings of the CFA indicated support for the original four-factor model. Additional analyses of the MGCFA method support the measurement (configural, metric and strong) invariant and practical invariant components of this model. There was an invariant across gender. There was partially invariant across groups of levels of education. The scale exists in groups of levels of education assess the same concepts of, excluding Items 15 and 10. Given that this study is the first investigation for the structure of the effectiveness scale.

Nonlinear analysis of thin shallow arches subject to snap-through using truss models

  • Xenidis, H.;Morfidis, K.;Papadopoulos, P.G.
    • Structural Engineering and Mechanics
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    • v.45 no.4
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    • pp.521-542
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    • 2013
  • In this study a truss model is used for the geometrically nonlinear static and dynamic analysis of a thin shallow arch subject to snap-through. Thanks to the very simple geometry of a truss, the equilibrium conditions can be easily written and the global stiffness matrix can be easily updated with respect to the deformed structure, within each step of the analysis. A very coarse discretization is applied; so, in a very simple way, the high frequency modes are suppressed from the beginning and there is no need to develop a complicated reduced-order technique. Two short computer programs have been developed for the geometrically nonlinear static analysis by displacement control of a plane truss model of a structure as well as for its dynamic analysis by the step-by-step time integration algorithm of trapezoidal rule, combined with a predictor-corrector technique. These two short, fully documented computer programs are applied on the geometrically nonlinear static and dynamic analysis of a specific thin shallow arch subject to snap-through.

Computer Simulation on the Structure and Electrical Characteristics of Power VDMOSFET based on Numerical Analysis (수치해석에 의한 전력용 VDMOSFET의 구조와 전기적 특성에 관한 컴퓨터 시뮬레이션)

  • Park, Bae-Woong;Lee, Woo-Sun
    • Proceedings of the KIEE Conference
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    • 1989.07a
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    • pp.548-551
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    • 1989
  • Two dimensional numerical analysis program of power VDMOSFET structure has been developed. Modeling and analysis on the electrical characteristics of the device are presented These are available for the device structure optimization and physical understanding of the behavior of the device

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Realistic pore structure of Portland cement paste: experimental study and numerical simulation

  • Ma, Hongyan;Li, Zongjin
    • Computers and Concrete
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    • v.11 no.4
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    • pp.317-336
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    • 2013
  • In this study, the pore structure of Portland cement paste is experimentally characterized by MIP (mercury intrusion porosimetry) and nitrogen adsorption, and simulated by a newly developed status-oriented computer model. Cement pastes with w/c=0.3, 0.4 and 0.5 at ages from 1 day to 120 days are comprehensively investigated. It is found that MIP cannot generate valid pore size distribution curves for cement paste. Nevertheless, nitrogen adsorption can give much more realistic pore size distribution curves of small capillary pores, and these curves follow the same distribution mode. While, large capillary pores can be effectively characterized by the newly developed computer model, and the validity of this model has been proved by BSE imaging plus image analysis. Based on the experimental findings and numerical simulation, a hypothesis is proposed to explain the formation mechanism of the capillary pore system, and the realistic representation of the pore structure of hydrated cement paste is established.

Power Quality Monitoring System with a New Distributed Monitoring Structure

  • Won, Dong-Jun;Chung, Il-Yop;Kim, Joong-Moon;Ahn, Seon-Ju;Moon, Seung-Il;Seo, Jang-Cheol;Choe, Jong-Woong
    • KIEE International Transactions on Power Engineering
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    • v.4A no.4
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    • pp.214-220
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    • 2004
  • Power quality monitoring is the cornerstone for power quality analysis, diagnosis and improvement. The measurement of power quality (PQ) evolves from instantaneous metering to continuous monitoring. Furthermore, recent technologies enable us to construct more flexible, reliable, rapid and economical power quality monitoring system (PQMS). Therefore, this paper presents an improved PQMS with a new distributed monitoring structure. The proposed PQMS consists of a PQ meter, PQ analyzer and GUI. The PQ meter only collects raw data and the PQ analyzer performs power quality analysis. It has several advantages compared to conventional structures in economic efficiency, modularity, speed, etc. PQ monitoring algorithms to catch steady-state trends and to detect PQ events are also adapted to the proposed structure. Using the proposed structure and monitoring algorithm, a prototype PQMS is constructed and real-time testing is performed.

METHOD FOR THE ANALYSIS OF TEMPORAL CHANGE OF PHYSICAL STRUCTURE IN THE INSTRUMENTATION AND CONTROL LIFE-CYCLE

  • Goring, Markus;Fay, Alexander
    • Nuclear Engineering and Technology
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    • v.45 no.5
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    • pp.653-664
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    • 2013
  • The design of computer-based instrumentation and control (I&C) systems is determined by the allocation of I&C functions to I&C systems and components. Due to the characteristics of computer-based technology, component failures can negatively affect several I&C functions, so that the reliability proof of the I&C systems requires the accomplishment of I&C system design analyses throughout the I&C life-cycle. On one hand, this paper proposes the restructuring of the sequential IEC 61513 I&C life-cycle according to the V-model, so as to adequately integrate the concept of verification and validation. On the other hand, based on a metamodel for the modeling of I&C systems, this paper introduces a method for the modeling and analysis of the effects with respect to the superposition of failure combinations and event sequences on the I&C system design, i.e. the temporal change of physical structure is analyzed. In the first step, the method is concerned with the modeling of the I&C systems. In the second step, the method considers the analysis of temporal change of physical structure, which integrates the concepts of the diversity and defense-in-depth analysis, fault tree analysis, event tree analysis, and failure mode and effects analysis.

Optimization Analysis for Homogeneous Field Structure of GTEM-CELL (GTEM-CELL의 균일한 필드구조를 갖기위한 최적화 분석)

  • Kim, Jong-Seong;Seo, Kang;Jeong, Seong-IL;Lee, Han-Young;Lee, Jong-Arc
    • Journal of IKEEE
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    • v.7 no.2 s.13
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    • pp.218-222
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    • 2003
  • Even if using the standard field test which radiation of electric wave and measurement test equipment there are difficult thing that building test equipment. so, we can use the substitution test field. In this paper, for optimization analysis for homogeneous field structure of GTEM-CELL (Giga hertz Transverse Electro Magnetic Cell) that calculate electromagnetic field characteristic for variable of each structure and characteristic impedance inner conductor.

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Finite Element Vibration Analysis of Multiply Interconnected Structure with Cyclic Symmetry (순환대칭으로 다중연결된 구조물의 유한요소 진동해석)

  • 김창부;안종섭;심수섭
    • Journal of KSNVE
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    • v.7 no.4
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    • pp.637-644
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    • 1997
  • In this paper, a method of finite element analysis is presented for efficient calculation of vibration characteristics of not only simply interconnected structure with cyclic symmetry but also multiply interconnected structure with cyclic symmetry by using discrete Fourier trandform by means of a computer with small memory in a short time. Simply interconnected structure means it is composed of substructures which are adjacent themselves in circumferential direction. First, a mathematical model of multiply interconnected structure with cyclic symmetry is defined. The multiply interconnected structure is partitioned into substructures with the same goemetric configuration and constraint eqauations to be satisfied on connecting boundaries are defined. Nodal displacements and forces are transformed into complex forms through discrete Fourier transform and then finite element analysis is performed for just only a representative substructure. In free vibration analysis, natural frequencies of a whole structure can be obtained through a series of calculation for a substructure along the number of nodal diameter. And in forced vibration analysis, forced response of whole structure can be achieved by using inverse discrete Fourier transform of results which come from analysis for a substructure.

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Analysis of Decoupling Capacitor for High Frequency Systems

  • Jung, Y.C.;Hong, K.K.;Kim, H.M.;Hong, S.K.;Kim, C.J.
    • Proceedings of the IEEK Conference
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    • 2007.07a
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    • pp.437-438
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    • 2007
  • In this paper a embedded decoupling capacitor design with gap structure will be discussed. A novel structure is modeling and analization by High Frequency Structure Simulator (HFSS). Proposed capacitor have $2m{\times}2m$ in rectangular shape. The film thickness of copper/dielectric film/substrate is respectively 35um/20um/35um. A dielectric layer of BaTiO3/epoxy has the relative permittivity of 25. Compare of the planar decoupling capacitor, capacitance densities of this structure in the range of $55{\mu}F$/mm2 have been obtained with 50um gap while capacitance densities of planar structure $55{\mu}F$/mm2 in the same size. The frequency dependent behavior of capacitors is numerically extracted over a wide frequency bandwidth 500MHz-7GHz. The decoupling capacitor can work at high frequency band increasing the gap size.

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