• 제목/요약/키워드: critical theory

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엔터프라이즈 시스템 구현의 핵심성공요소에 관한 연구: 프로세스이론을 기반으로 한 실패사례 분석 (A Study on Critical Success Factors for Enterprise Systems Implementation: A Failure Case Analysis Based on Process Theory)

  • 김희웅;곽기영
    • 한국IT서비스학회지
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    • 제6권3호
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    • pp.251-272
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    • 2007
  • Although Enterprise Systems (ES) have promised major strategic benefits and process improvements from business and technology integration, their implementation has been plagued by a high failure rate and difficulty in realizing the promised benefits. For the purpose of understanding implementation failures, previous studies have focused on identifying critical success factors (CSFs) for information systems implementation. However, there has been little research on how these CSFs actually lead to successful results. In this study, based on process theory, we examined the process of ES implementation by explaining how the factors of ES implementation influence each other and how interaction among them produces results. Based on a failure case, we then developed a process model of ES implementation thus allowing us to explain the process of ES implementation. The proposed model facilitated an understanding of how repeating patterns of ES failure can be reversed. This model can be used for guiding new ES implementation projects.

Classical shell theory for instability analysis of concrete pipes conveying nanofluid

  • Keikha, Reza;Heidari, Ali;Hosseinabadi, Hamidreza;Haghighi, Mohammad Salkhordeh
    • Computers and Concrete
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    • 제22권2호
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    • pp.161-166
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    • 2018
  • This paper deals with the instability analysis of concrete pipes conveying viscous fluid-nanoparticle mixture. The fluid is mixed by $AL_2O_3$ nanoparticles where the effective material properties of fluid are obtained by mixture rule. The applied force by the internal fluid is calculated by Navier-Stokes equation. The structure is simulated by classical cylindrical shell theory and using energy method and Hamilton's principle, the motion equations are derived. Based on Navier method, the critical fluid velocity of the structure is calculated and the effects of different parameters such as fluid velocity, volume percent of nanoparticle in fluid and geometrical parameters of the pipe are considered. The results present that with increasing the volume percent of nanoparticle in fluid, the critical fluid velocity increase.

Stability of the porous orthotropic laminated composite plates via the hyperbolic shear deformation theory

  • Ferruh Turan
    • Steel and Composite Structures
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    • 제48권2호
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    • pp.145-161
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    • 2023
  • This study investigates the influences of porosity on the stability of the orthotropic laminated plates under uniaxial and biaxial loadings based on the hyperbolic shear deformation theory. Three different porosity distribution are considered with three specific functions through the plate thickness. The stability equations of porous orthotropic laminated plates are derived by the virtual work principle. Applying the Galerkin method to partial differential equations, the critical buckling load relation of porous orthotropic laminated plates is obtained. After validating the accuracy of the proposed formulation in accordance with the available literature, a parametric analysis is performed to observe the sensitivity of the critical buckling load to shear deformation, porosity, orthotropy, loading factor, and different geometric properties.

주행 중 디스크 온도 변화와 열간 저더 임계속도와의 관계 예측 (A Prediction of the Relation between the Disc Brake Temperature and the Hot Judder Critical Speed)

  • 김재민;이민규;김범진;조종두
    • 한국자동차공학회논문집
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    • 제21권1호
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    • pp.61-67
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    • 2013
  • In this paper, it was studied how the critical speed which could occur hot judder due to disk temperature. Through the dynamometer experiment, we measured the critical velocity and surface temperature when the hot judder occur on the disk break. Also with the critical velocity theory equation and the temperature change graph of factors which used in the equation, we was induced experiment equation including theory equation and experiment values. And it has compared with the method which approach as linea. From this, we predicted the change of critical speed which could occur hot judder due to disk temperature. In addition, critical speed graph has compared with actual driving speed and disc temperature at a vehicle test. Therefore it was estimate to possibility of arising hot judder.

Mindlin 판 이론을 적용한 단순지지 단면 접수평판의 음향방사효율 수치해석 (A Numerical Analysis on Acoustic Radiation Efficiency of One Side-Wetted Rectangular Mindlin Plate with Simply Supported Boundaries)

  • 이종호;조대승
    • 대한조선학회논문집
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    • 제55권4호
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    • pp.281-288
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    • 2018
  • Acoustic radiation efficiency is a crucial factor to estimate Underwater Radiated Noise (URN) of ships accurately. This paper describes a numerical method to analyse acoustic radiation efficiency of one side-wetted rectangular Mindlin plate with simply supported boundaries excited by a harmonic point force. Transverse displacements of plate and acoustic radiation pressures are evaluated by the mode superposition method. The acoustic radiation efficiencies analyzed by both Mindlin and thin plate theories show little differences at monopole and corner modes of low frequency regions but relatively large differences at edge and critical modes of high frequency regions. Especially, the critical frequency with the highest acoustic radiation efficiency evaluated by the Mindlin plate theory is higher than that of thin plate theory. In addition, the acoustic loading effect of fluid also increases bending wave-number of plate and its critical frequency. Finally, the acoustic radiation characteristics of plates with different aspect ratios and thicknesses through numerical analyses are investigated and discussed.

Critical buckling load of chiral double-walled carbon nanotube using non-local theory elasticity

  • Chemi, Awda;Heireche, Houari;Zidour, Mohamed;Rakrak, Kaddour;Bousahla, Abdelmoumen Anis
    • Advances in nano research
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    • 제3권4호
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    • pp.193-206
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    • 2015
  • The present paper investigate the elastic buckling of chiral double-walled carbon nanotubes (DWCNTs) under axial compression. Using the non-local elasticity theory, Timoshenko beam model has been implemented. According to the governing equations of non-local theory, the analytical solution is derived and the solution for non-local critical buckling loads is obtained. The numerical results show the influence of non-local small-scale coefficient, the vibrational mode number, the chirality of carbon nanotube and aspect ratio of the (DWCNTs) on non-local critical buckling loads of the (DWCNTs). The results indicate the dependence of non-local critical buckling loads on the chirality of single-walled carbon nanotube with increase the non-local small-scale coefficient, the vibrational mode number and aspect ratio of length to diameter.

근대 이후 한국주거의 미시사를 보는 다양한 관점 (Various Perspectives to Read the Micro-History of Korean Housing after the Period of Opening the Port)

  • 홍형옥
    • 가정과삶의질연구
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    • 제23권5호
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    • pp.79-92
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    • 2005
  • The purpose of this study was to explore the various perspectives to read micro-history of Korean housing after the period of Opening the Port for foreigners. This study were designed to adapt original theory for exploring the unique housing perspectives without using strict basic assumption which were already developed in the area of sociology, history, anthropology and philosophy. Research method applied was literature review. Each perspective might give useful insight to read the micro-history of Korean housing on the way of change after the Period of Opening the Port in Korea. Adapted perspectives to housing history were critical theory perspective, microsociological perspective, everyday life perspective(phenomenology tradition, symbolic interaction tradition, Marxist tradition), discourse perspective, exchange theory perspective, conflict theory perspective, and life course perspective. Conclusively, each perspective must be adapted multi-supportively to read the housing phenomena, because housing change derived from complex causes and factors. The fruit of this study was to ensure the adaptable viewpoint to housing were useful to read the micro-history of housing change.

러프집합론의 철학적 함의 (A Philosophical Implication of Rough Set Theory)

  • 박창균
    • 논리연구
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    • 제17권2호
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    • pp.349-358
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    • 2014
  • 불완전한 지식의 문제는 오랫동안 인간이 해결하려는 것이었다. 인공지능에서 불완전한 지식의 문제를 다루기 위해 파블락은 러프집합론을 1982년에 제안하였다. 러프집합론은 다음과 같은 두 가지 흥미있는 성질을 가지고 있다. 먼저 하나의 러프집합은 지식기반에 따라 같은 집합이 아닌 다른 집합으로 간주된다는 것이다. 그리고 서로 다른 러프집합도 어떤 지식 기반에서 보면 서로 같은 집합으로 여겨진다는 것이다. 이러한 성질은 의미있는 철학적 해석을 낳는다. 즉 하나의 개념이나 사건은 다른 철학적 관점에서 다른 것으로 이해되기도 하고, 서로 다른 개념이나 사건도 어떤 관점에 따라서는 같은 것으로 간주될 수 있다는 것이다. 본고에서는 이러한 러프집합의 성질은 비판적 실재론이나 과학철학에서 관찰의 이론적재성을 지지하는 수학적 모델로 취급될 수 있다고 주장한다.

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On the Optical Activity of Critical Fluid

  • Lee, Dong-Jae;Kim, Shoon-Kyung
    • Bulletin of the Korean Chemical Society
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    • 제6권3호
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    • pp.123-124
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    • 1985
  • The optical activity of a fluid in the extreme critical region, where the Ornstein-Zernike theory does not hold, is explicitly obtained. We suggest new experimental methods to measure the critical exponent for correlation function by using the results of circular dichroism and optical rotation given in this paper.

Buckling analysis of linearly tapered micro-columns based on strain gradient elasticity

  • Akgoz, Bekir;Civalek, Omer
    • Structural Engineering and Mechanics
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    • 제48권2호
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    • pp.195-205
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    • 2013
  • The buckling problem of linearly tapered micro-columns is investigated on the basis of modified strain gradient elasticity theory. Bernoulli-Euler beam theory is used to model the non-uniform micro column. Rayleigh-Ritz solution method is utilized to obtain the critical buckling loads of the tapered cantilever micro-columns for different taper ratios. Some comparative results for the cases of rectangular and circular cross-sections are presented in graphical and tabular form to show the differences between the results obtained by modified strain gradient elasticity theory and those achieved by modified couple stress and classical theories. From the results, it is observed that the differences between critical buckling loads achieved by classical and those predicted by non-classical theories are considerable for smaller values of the ratio of the micro-column thickness (or diameter) at its bottom end to the additional material length scale parameters and the differences also increase due to increasing of the taper ratio.