• 제목/요약/키워드: incremental approach

검색결과 262건 처리시간 0.024초

An incremental convex programming model of the elastic frictional contact problems

  • Mohamed, S.A.;Helal, M.M.;Mahmoud, F.F.
    • Structural Engineering and Mechanics
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    • 제23권4호
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    • pp.431-447
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    • 2006
  • A new incremental finite element model is developed to simulate the frictional contact of elastic bodies. The incremental convex programming method is exploited, in the framework of finite element approach, to recast the variational inequality principle of contact problem in a discretized form. The non-classical friction model of Oden and Pires is adopted, however, the friction effect is represented by an equivalent non-linear stiffness rather than additional constraints. Different parametric studies are worked out to address the versatility of the proposed model.

A Diffraction Transfer Function Approach to the Calculation of the Transient Field of Acoustic Radiators

  • Lee, Chan-Kil
    • ETRI Journal
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    • 제16권1호
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    • pp.1-15
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    • 1994
  • A computationally-efficient approach to the calculation of the transient field of an acoustic radiator was developed. With this approach, a planar or curved source, radiating either continuous or pulsed waves, is divided into a finite number of shifted and/or rotated versions of an incremental source such that the Fraunhofer approximation holds at each field point. The acoustic field from the incremental source is given by a 2-D spatial Fourier transform. The diffraction transfer function of the entire source can be expressed as a sum of Fraunhofer diffraction pattern of the incremental sources with the appropriate coordinate transformations for the particular geometry of the radiator. For a given spectrum of radiator velocity, the transient field can be computed directly in the frequency domain using the diffraction transfer function. To determine the accuracy of the proposed approach, the impulse response was derived using the inverse Fourier transform. The results obtained agree well with published data obtained using the impulse response approach. The computational efficiency of the proposed method compares favorably to those of the point source method and the impulse response approach.

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다수의 투자대안들에 대한 수익률 기준의 경제성 평가방법 (Economic Evaluation Method Based on Rate of Return for Multiple Investment Alternatives)

  • 김진욱
    • 산업경영시스템학회지
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    • 제42권1호
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    • pp.137-142
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    • 2019
  • There are two methods for evaluating two or more mutually exclusive projects. One is a total investment approach and the other is an incremental investment approach. The former can rank projects by the criterion of the net present value, but the latter can't do it. An incremental investment approach is only possible when all pairwise alternatives are compared. Thus an incremental investment approach is superior in ranking them over an incremental investment approach. To do so, a principle of comparison must be established. Comparisons of profitability are reasonable when operating the same amount of investment over the same period of time. One principle is that all projects are invested in the largest of the projects. Another principle is that all projects are invested during the longest project life of the projects. In this paper, even if the principle is followed, it will be shown that the external rate of return fails to rank them. However, the productive rate of return criterion would prove to be able to rank them like the net present value standard, provided that the principle of comparison is kept. In addition, rate of returns can be assessed so that all mutually exclusive projects can be compared at once, such as on the criterion of the net present value. That is, it can be also compared with many other returns, such as the profit rates on financial investments or real investments.

인크리멘탈 이벤트 - 구동 HDL 시뮬레이션에의 실제적 접근법 (A Practical Approach to Incremental Event-driven HDL Simulation)

  • 양세양;심규호
    • 정보처리학회논문지:컴퓨터 및 통신 시스템
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    • 제3권3호
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    • pp.73-80
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    • 2014
  • 본 논문에서는 이벤트구동 HDL 시뮬레이션에서 시뮬레이션 실행 시간 단축을 위한 인크리멘탈 시뮬레이션 방법을 제시한다. 일반적으로 시뮬레이션 과정은 일련의 반복적인 설계수정들과 동반되어 반복적으로 일어난다. 인크리멘탈 시뮬레이션은 이와같은 반복적인 시뮬레이션에서 설계수정 전의 시뮬레이션 결과를 이용하여서 설계수정 후에 진행되는 시뮬레이션의 수행 시간을 단축할 수 있는 효과적인 시뮬레이션 방법이다. 본 논문에서 제안된 인크리멘탈 시뮬레이션 방법의 유용함은 다양한 실제 디자인들에 적용한 실험을 통하여 확인할 수 있었다.

Simple solutions of an opening in elastic-brittle plastic rock mass by total strain and incremental approaches

  • Park, Kyungho
    • Geomechanics and Engineering
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    • 제13권4호
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    • pp.585-600
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    • 2017
  • This study deals with simple solutions for a spherical or circular opening excavated in elastic-brittle plastic rock mass compatible with a linear Mohr-Coulomb (M-C) or a nonlinear Hoek-Brown (H-B) yield criterion. Based on total strain approach, the closed-form solutions of stresses and displacement are derived simultaneously for circular and spherical openings using original H-B and M-C yield criteria. Two simple numerical procedures are proposed for the solution of generalized H-B and M-C yield criteria. Based on incremental approach, the similarity solution is derived for circular and spherical openings using generalized H-B and M-C yield criteria. The classical Runge-Kutta method is used to integrate the first-order ordinary differential equations. Using three data sets for M-C and H-B models, the results of the radial displacements, the spreading of the plastic radius with decreasing pressure, and the radial and circumferential stresses in the plastic region are compared. Excellent agreement among the solutions is obtained for all cases of spherical and circular openings. The importance of the use of proper initial values in the similarity solution is discussed.

설계특징형상으로부터 가공특징형상 추출 (Incremental Feature Recognition from Feature-based Design Model)

  • 이재열;김광수
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1994년도 추계학술대회 논문집
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    • pp.737-742
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    • 1994
  • In this paper , we propose an incremental approach for recognizing a class of machining features from a featurebased design model as a part design proceeds, utilizing various information such as nominal geometry, design intents, and design feature characteristics. The proposed apptroach can handle complex intersecting features and protrusion features designed on oblique faces. The class of recognized volumetric machining features can be expressed as Material Removal Shape Element Volumes (MRSEVs), a PDES/STEP-based library of machining features.

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Face recognition invariant to partial occlusions

  • Aisha, Azeem;Muhammad, Sharif;Hussain, Shah Jamal;Mudassar, Raza
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제8권7호
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    • pp.2496-2511
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    • 2014
  • Face recognition is considered a complex biometrics in the field of image processing mainly due to the constraints imposed by variation in the appearance of facial images. These variations in appearance are affected by differences in expressions and/or occlusions (sunglasses, scarf etc.). This paper discusses incremental Kernel Fisher Discriminate Analysis on sub-classes for dealing with partial occlusions and variant expressions. This framework focuses on the division of classes into fixed size sub-classes for effective feature extraction. For this purpose, it modifies the traditional Linear Discriminant Analysis into incremental approach in the kernel space. Experiments are performed on AR, ORL, Yale B and MIT-CBCL face databases. The results show a significant improvement in face recognition.

ART 모델의 multirun 횟수 감소에 관한 연구 (A Study on decreasing the Number of Multirun in ART Model)

  • 김미나;김도년;조동섭
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1995년도 하계학술대회 논문집 B
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    • pp.986-988
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    • 1995
  • The ART(Adaptive Resonance Theory) model is self- organized with nonstationary input patterns in real time. But there is a multirun problem caused by fault clustering, or pertubated clustering and confines the advantage of the stationary real-time processing in ART model. In this paper, we propose the incremental vigilance threshold approach to decrease the number of multiruns. The incremental vigilance threshold approach is to learn with incremental vigilance threshold and competition with clusters.

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An Incremental, Iterative and Interative Ontology Matching Approach

  • Wagner, Fernando;Macedo, Jose A.F.;Loscio, Bernadette
    • 정보화연구
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    • 제9권4호
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    • pp.357-363
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    • 2012
  • Ontologies are being used in order to define common vocabularies to describe the elements of schemas involved in a particular application. The problem of finding correspondences between ontologies concepts, called ontology matching, consists in the discovery of correspondences between terms of vocabularies (represented by ontologies) used by various applications. The majority of solutions proposed in the literature, despite being fully automatic, has heuristic nature and may produce nonsatisfactory results. The problem intensifies when dealing with large data sources. The goal of this paper is to propose a method for generation and incremental refinement of correspondences between ontologies. The proposed approach uses filtering techniques, as well as user feedback to support the generation and refinement of such matches. For validation purposes, a tool was developed and some experiments were conducted.

Incremental Information Content of Cash Flow and Earnings in the Iranian Capital Market

  • Asgari, Leila;Salehi, Mahdi;Mohammadi, Ali
    • 산경연구논집
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    • 제5권1호
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    • pp.5-9
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    • 2014
  • Purpose - This study aims to examine the incremental information content of cash flw from operations and earnings in the Iranian capital market. Design, methodology, and approach - Based on market-based accounting research, this study uses statistical associations between accounting data (earnings and cash flw) and stock returns to assess/measure the incremental information content (value relevance) of cash flw and earnings. A multivariate regression model based on panel data is used to examine the incremental information content of earnings and cash flow from operations. Results - The results show that both earnings and cash flow from operations have incremental information content beyond each other. These results are consistent with the findings of recent studies. Overall, the fidings of this study support the usefulness of cash flw information in addition to earnings, in fim valuation by investors in the Iranian market. Conclusions - The study makes the following contributions to the Iranian literature on incremental information content of cash flw and earnings. First, this study employs actual cash flw data derived from cash flw statements. Second, this study employs a large sample size for a more recent period.