• Title/Summary/Keyword: function analysis

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Stress analysis of creep material containing elliptical rigid inclusion by complex pseudo-stress function (복소 유사응력함수에 의한 타원 강체함유물을 내포하는 크립재료의 응력해석)

  • Lee, Kang-Yong;Kim, Jong-Sung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.22 no.2
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    • pp.408-415
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    • 1998
  • The analysis model is the power law creep material containing an elliptical rigid inclusion subjected to the arbitrarily directional stress on infinite boudary. The stress analysis is performed using the conformal mapping function and complex pseudo-stress function. The stress distributions near an elliptical rigid inclusion are obtained with various ellipse shapes, strain hardening exponents and directions of applied stress.

The concept Analysis of Physical Activity (신체활동(Physical activity)의 개념분석)

  • Choi, Jung-An;Choe, Myoung-Ae
    • Journal of Korean Biological Nursing Science
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    • v.6 no.1
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    • pp.17-31
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    • 2004
  • The purpose of this study was to analyze the concept of physical activity. The method was based on the steps of concept analysis by Walker and Avant(1988). The result of this study were as follows; Upon the concept analysis, physical activity is defined as a series of bodily movements which is performed voluntarily by individual. The defining attributes of physical activity were a series of bodily movements, energy expenditure, goal-directedness, and self-control of the body. The antecedents of physical activity were neuromusculoskeletal function, cardiopulmonary function and cognitive function. And the consequences of physical activity were improvement of physical function, induction of fatigue, and need(physiopsychosocial) satisfaction. Further studies are needed to develop the concept of physical activity using the Hybrid model. In addition, considering personal characteristics it is important to study the facilitating factors of physical activity.

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Time Lag Analysis Using Phase of Flame Transfer Function (화염전달함수의 위상차를 이용한 시간지연 분석)

  • Pyo, Yeongmin;Kim, Jihwan;Kim, Daesik
    • Journal of ILASS-Korea
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    • v.21 no.2
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    • pp.104-110
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    • 2016
  • Main purpose of the current paper is to show results of time lag analysis using phase information of flame transfer function in order to predict combustion instabilities in a gas turbine combustor. The flame transfer function (FTF) is modeled using a commercial Computational Fluid Dynamics (CFD) code (Fluent). Comparisons of the modeled flame shapes with the measured ones were made using the optimized heat transfer conditions and combustion models. The FTF modeling results show a quite good agreement with the measurement data in predicting the phase delay (i.e. time lag). Time lag analysis results using the phase of FTF shows better combustion instability prediction accuracy than using time lag calculated from the steady state flame length.

A Study on the Characteristics of Pressure Wave Propagation in Automotive Exhaust System (자동차 배기계의 압력파 전파특성에 관한 연구)

  • 차경옥;이준서;김형섭
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.4
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    • pp.18-26
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    • 1996
  • Based on experimental analysis, the characteristics of pulsating pressure wave propagation is clarified by testing of 4-stroke gasoline engine. The pulsating pressure wave in exhaust system is generated by pulsating gas flow due to working of exhaust valve. The pulsating pressure wave is closely concerned to the loss of engine power according to back pressure and exhaust noise. It is difficult to exactly calculate pulsating pressure wave propagation in exhaust system because of nonlinear effect. Therefore, in the first step for solving these problems, this paper contains experimental model and analysis method which are applied two-port network analysis. Also, it shows coherence function, frequency response function, back pressure, and gradient of temperature in exhaust system.

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A Study on the Characteristics of Pressure Wave Propagation in Spark Ignition Engine Exhaust System (점화기관 배기계의 압력과 전파특성에 관한 연구)

  • 박진용
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1996.03a
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    • pp.72-78
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    • 1996
  • Based on experimental analysis, the characteristics of pulsating pressure wave propagation is clarified by testing of 4-stroke gasoline engine. The pulsating pressure wave in exhaust system is generated gyulsating gas flow due the working of exhaust valve. The pulsating pressure wave is closely concerned to the loss of engine power according to back pressure and exhaust noise. It is difficult to exactly calculate pulsating pressure wave nonlinear effect. Therefore, in the first step for solving these problems, this paper contains experimental model and analysis method which are applied two-port network analysis. Also, it shows coherence function, frequency response function. back pressure, and gradient of temperature in exhaust system.

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High-throughput identification of chrysanthemum gene function and expression: An overview and an effective proposition

  • Nguyen, Toan Khac;Lim, Jin Hee
    • Journal of Plant Biotechnology
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    • v.48 no.3
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    • pp.139-147
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    • 2021
  • Since whole-genome duplication (WGD) of diploid Chrysanthemum nankingense and de novo assembly whole-genome of C. seticuspe have been obtained, they have afforded to perceive the diversity evolution and gene discovery in the improved investigation of chrysanthemum breeding. The robust tools of high-throughput identification and analysis of gene function and expression produce their vast importance in chrysanthemum genomics. However, the gigantic genome size and heterozygosity are also mentioned as the major obstacles preventing the chrysanthemum breeding practices and functional genomics analysis. Nonetheless, some of technological contemporaries provide scientific efficient and promising solutions to diminish the drawbacks and investigate the high proficient methods for generous phenotyping data obtaining and system progress in future perspectives. This review provides valuable strategies for a broad overview about the high-throughput identification, and molecular analysis of gene function and expression in chrysanthemum. We also contribute the efficient proposition about specific protocols for considering chrysanthemum genes. In further perspective, the proper high-throughput identification will continue to advance rapidly and advertise the next generation in chrysanthemum breeding.

A Non-Linear Exponential(NLINEX) Loss Function in Bayesian Analysis

  • Islam, A.F.M.Saiful;Roy, M.K.;Ali, M.Masoom
    • Journal of the Korean Data and Information Science Society
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    • v.15 no.4
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    • pp.899-910
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    • 2004
  • In this paper we have proposed a new loss function, namely, non-linear exponential(NLINEX) loss function, which is quite asymmetric in nature. We obtained the Bayes estimator under exponential(LINEX) and squared error(SE) loss functions. Moreover, a numerical comparison among the Bayes estimators of power function distribution under SE, LINEX, and NLINEX loss function have been made.

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Cost Estimation and Validation based on Natural Language Requirement Specifications

  • So Young Moon;R. Young Chul Kim
    • International Journal of Internet, Broadcasting and Communication
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    • v.15 no.2
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    • pp.218-226
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    • 2023
  • In Korea, we still use function point based cost estimations for software size and cost of a project. The current problem is that we make difficultly calculating function points with requirements and also have less accurate. That is, it is difficult for non-experts to analyze requirements and calculate function point values with them, and even experts often derive different function points. In addition, all stakeholders strongly make the validity and accuracy of the function point values of the project before /after the development is completed. There are methods for performing function point analysis using source code [1][2][3][4] and some researchers [5][6][7] attempt empirical verification of function points about the estimated cost. There is no research on automatic cost validation with source code after the final development is completed. In this paper, we propose automatically how to calculate Function Points based on natural language requirements before development and prove FP calculation based on the final source code after development. We expect validation by comparing the function scores calculated by forward engineering and reverse engineering methods.

A Study on the Identification of Vibration Sources of a Gasoline Engine by Multi-Dimensional Spectral Analysis (다차원 스펙트럼 해석 에 의한 가솔린 엔진 의 진동원 검출 에 관한 연구)

  • 강명순;오재응;서상현
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.9 no.6
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    • pp.691-698
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    • 1985
  • This paper presents a method for the identification of vibration sources in a multiple input system where the input source may be coherent with each other. Using multi-dimensional spectral analysis, it is found that one of the most significant vibration sources of a gasoline engine is the pressure variation within the cylinder. In this analysis the concepts of residual spectral analysis and the partial coherence function are applied. Finally, the overall levels of the acceleration on the cylinder block obtained by multi-dimensional spectral analysis are compared with those by the frequency response function approach. The experimental results have shown a good agreement with the results calculated by this method the input sources are coherent strongly each other.

Sensitivity analysis for optimal design of piezoelectric structures (압전지능구조물의 최적설계를 위한 민감도 해석)

  • 김재환
    • Journal of KSNVE
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    • v.8 no.2
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    • pp.267-273
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    • 1998
  • This study aims at performing sensitivity analysis of piezoelectric smart structure for minimizing radiated noise from the structure, The structure consists of a flat plate on which disk shaped piezoelectric actuator is mounted, and finite element modeling is used for the structure. The finite element modeling uses a combination of three dimensional piezoelectric, flat shell and transition elements so thus it can take into account the coupling effects of the piezoelectric device precisely and it can also reduce the degrees of freedom of the finite element model. Electric potential on the piezoelectric actuator is taken as a design variable and total radiated power of the structure is chosen as an objective function. The objective function can be represented as Rayleigh's integral equation and is a function of normal displacements of the structure. For the convenience of computation, all degrees of freedom of the finite element equation is condensed out except the normal displacements of the structure. To perform the design sensitivity analysis, the derivative of the objective function with respect to the normal displacements is found, and the derivative of the norma displacements with respect to the design variable is calculated from the finite element equation by using so called the adjoint variable method. The analysis results are compared with those of the finite difference method, and shows a good agreement. This sensitivity analysis is faster and more accurate than the finite difference method. Once the sensitivity analysis program is used for gradient-based optimizations, one could achieve a better convergence rate than non-derivative methods for optimal design of piezoelectric smart structures.

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