• Title/Summary/Keyword: Representative principle

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Multiscale modeling of elasto-viscoplastic polycrystals subjected to finite deformations

  • Matous, Karel;Maniatty, Antoinette M.
    • Interaction and multiscale mechanics
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    • v.2 no.4
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    • pp.375-396
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    • 2009
  • In the present work, the elasto-viscoplastic behavior, interactions between grains, and the texture evolution in polycrystalline materials subjected to finite deformations are modeled using a multiscale analysis procedure within a finite element framework. Computational homogenization is used to relate the grain (meso) scale to the macroscale. Specifically, a polycrystal is modeled by a material representative volume element (RVE) consisting of an aggregate of grains, and a periodic distribution of such unit cells is considered to describe material behavior locally on the macroscale. The elastic behavior is defined by a hyperelastic potential, and the viscoplastic response is modeled by a simple power law complemented by a work hardening equation. The finite element framework is based on a Lagrangian formulation, where a kinematic split of the deformation gradient into volume preserving and volumetric parts together with a three-field form of the Hu-Washizu variational principle is adopted to create a stable finite element method. Examples involving simple deformations of an aluminum alloy are modeled to predict inhomogeneous fields on the grain scale, and the macroscopic effective stress-strain curve and texture evolution are compared to those obtained using both upper and lower bound models.

Validity and Reliability of the Fagerstrom Test for Cigarette Dependence in a Sample of Arabic Speaking UK-Resident Yemeni Khat Chewers

  • Kassim, Saba;Salam, Mohamed;Croucher, Ray
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.4
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    • pp.1285-1288
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    • 2012
  • Background: The Fagerstrom Test for Cigarette Dependence (FTCD) (formally FTND) is widely used for measuring physical dependence on nicotine. Objective: To explore the cross cultural validity and reliability of FTCD amongst Arabic speaker cigarette consumers who chew khat leaf, a stimulant green leaf. Methods: The psychometric properties of the FTCD were assessed in a subsample (91regular cigarette smokers) of purposively selected 204 UK-resident Yemeni khat chewers recruited during random visits to khat sale outlets. Data were collected via a structured face-to-face interview. Data analyses included descriptive tests and factor analysis. Results: Two factors were obtained by a principle axis factor analysis and these were termed as urgency of restoring the level of nicotine after abstinence during sleeping and maintaining the level of nicotine during waking. The internal reliability (Cronbach's alpha coefficient) of the whole FTCD is low (.68) as well as for the two subscales (.60) and (.62) respectively. Conclusion: The psychometric properties of the Arabic version of the FTCD scale in this sample of Yemeni khat chewers who smoked regularly confirmed what has been established in other cultural settings. The findings of this study have yet to be cross validated amongst other appropriately representative sample of Arabic speakers.

A Study on the Furniture Design of Charles Rennie Mackintosh (맥킨토시의 가구 디자인에 관한 연구)

  • Ryu, Sookhee
    • Journal of the Korea Furniture Society
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    • v.24 no.4
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    • pp.350-364
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    • 2013
  • Based on the background of the times and theoretical background that influenced the formation of the works of Charles Rennie Mackintosh, one of representative architects of Art Nouveau, this study examined the formative characteristics of furniture design by period. In addition, his influences on the modern furniture design were also reviewed. In the latter half of the 19th century, due to Arts and Crafts Movement, the popularity of Art Nouveau was not high in England and due to conservative and traditional culture, Mackintosh had difficult time to display his ability in England. On the other hand, because Glasgow, one of industrial cities located in the center of Scotland where he had grown was an open and modern city, Mackintosh could win international fame in architecture and furniture design thanks to the atmosphere. Furthermore, it is found from the formative characteristics of his works that Historicism, Arts and Crafts Movement and Japanese culture and the influences of Continent became his theoretical background. His works creatively combined the noble design of Scotland and Art Nouveau to be considered a simple and pure style with a straight tendency and his working period can be divided into Beginning, Middle and Last Period according to the formative characteristics of furniture design. His constituting principle that decorated the structure influenced the Wien Secession's activities to form Wiener Werkstaette and this finally became the important background to develop to 'Modernism Design' through Art Deco and Bauhaus.

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Unsupervised Clustering of Multivariate Time Series Microarray Experiments based on Incremental Non-Gaussian Analysis

  • Ng, Kam Swee;Yang, Hyung-Jeong;Kim, Soo-Hyung;Kim, Sun-Hee;Anh, Nguyen Thi Ngoc
    • International Journal of Contents
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    • v.8 no.1
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    • pp.23-29
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    • 2012
  • Multiple expression levels of genes obtained using time series microarray experiments have been exploited effectively to enhance understanding of a wide range of biological phenomena. However, the unique nature of microarray data is usually in the form of large matrices of expression genes with high dimensions. Among the huge number of genes presented in microarrays, only a small number of genes are expected to be effective for performing a certain task. Hence, discounting the majority of unaffected genes is the crucial goal of gene selection to improve accuracy for disease diagnosis. In this paper, a non-Gaussian weight matrix obtained from an incremental model is proposed to extract useful features of multivariate time series microarrays. The proposed method can automatically identify a small number of significant features via discovering hidden variables from a huge number of features. An unsupervised hierarchical clustering representative is then taken to evaluate the effectiveness of the proposed methodology. The proposed method achieves promising results based on predictive accuracy of clustering compared to existing methods of analysis. Furthermore, the proposed method offers a robust approach with low memory and computation costs.

A Study on Zhang Jie Bin's Qi Determinism of the Human Nature (명의(名醫) 장개빈(張介賓)의 기정품성론(氣定品性論) 연원고(淵源考) -송유(宋儒) 장재(張載)의 기질지성론(氣質之性論)과의 비교를 중심으로-)

  • Won, Jong Sil
    • Journal of Korean Medical classics
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    • v.17 no.4
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    • pp.69-80
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    • 2004
  • Nei Ching referred to as a canon of Chinese medicine is a comprehensive life philosophy that applied the life principle of the universe to the human body to combine the philosophical concept with the human nature as well as the functions of the body's organs. The book formed a complete system of a Qi Philosophy by using the medical terminology and theory based on the concept of Qi. It is remarkable that the Qi philosophy of Chang Tsai, who is a Neo-Confucianist and representative scholar of Qi philosophy in the era of Song Dynasty, has been influenced by the Qi philosophy in Nei Ching and developed into a Confucian school Furthermore, Chang Tsai's theory, in effect, impacted upon the rise of Qi Determination of the Human Nature in Medicine of Zhang Jie Bin who is a profound thinker in the era of Ming dynasty. As mentioned above, both traditional philosophy and medical philosophy in china in regard to Qi Theory have interacted and developed each other. This paper is to make a comparative study of the Qi Determination of the Human Nature proposed by Chang Tsai and Zhang Jie Bin and to trace the orgin of the Qi Determination of Human Nature.

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Statistical Characteristics of Fractal Dimension in Turbulent Prefixed Flame (난류 예혼합 화염에서의 프랙탈 차원의 통계적 특성)

  • Lee, Dae-Hun;Gwon, Se-Jin
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.1
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    • pp.18-26
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    • 2002
  • With the introduction of Fractal notation, various fields of engineering adopted fractal notation to express characteristics of geometry involved and one of the most frequently applied areas was turbulence. With research on turbulence regarding the surface as fractal geometry, attempts to analyze turbulent premised flame as fractal geometry also attracted attention as a tool for modeling, for the flame surface can be viewed as fractal geometry. Experiments focused on disclosure of flame characteristics by measuring fractal parameters were done by researchers. But robust principle or theory can't be extracted. Only reported modeling efforts using fractal dimension is flame speed model by Gouldin. This model gives good predictions of flame speed in unstrained case but not in highly strained flame condition. In this research, approaches regarding fractal dimension of flame as one representative value is pointed out as a reason for the absence of robust model. And as an extort to establish robust modeling, Presents methods treating fractal dimension as statistical variable. From this approach flame characteristics reported by experiments such as Da effect on flame structure can be seen quantitatively and shows possibility of flame modeling using fractal parameters with statistical method. From this result more quantitative model can be derived.

Edge Profile Correction for Modulation Transfer Function on Digital X-ray Imaging System (디지털 의료영상에서 Edge method에 의한 Modulation Transfer Function 보정방법과 특이성)

  • Kim, Jung-Min
    • Journal of radiological science and technology
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    • v.30 no.3
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    • pp.251-257
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    • 2007
  • Medical imaging zero-phase-sequence component in estimation for picture that is gotten that importance weight of digital device is increased day by day at the same time also so much important. Special quality about resolution uses Modulation Transfer Function by representative method to evaluate sharpness on important element in image quality. Get MTF converting slit, differentiating this making composition ESF edge method uses Excel by edge method in this study to be composition LSF get in fourier to informed measuring mean universally. Such method is considered that can help in principle grasping of step before make Program using C language as many as Matlab.

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Co-Evolutionary Algorithm and Extended Schema Theorem

  • Sim, Kwee-Bo;Jun, Hyo-Byung
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.2 no.1
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    • pp.95-110
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    • 1998
  • Evolutionary Algorithms (EAs) are population-based optimization methods based on the principle of Darwinian natural selection. The representative methodology in EAs is genetic algorithm (GA) proposed by J. H. Holland, and the theoretical foundations of GA are the Schema Theorem and the Building Block Hypothesis. In the meaning of these foundational concepts, simple genetic algorithm (SGA) allocate more trials to the schemata whose average fitness remains above average. Although SGA does well in many applications as an optimization method, still it does not guarantee the convergence of a global optimum in GA-hard problems and deceptive problems. Therefore as an alternative scheme, there is a growing interest in a co-evolutionary system, where two populations constantly interact and co-evolve in contrast with traditional single population evolutionary algorithm. In this paper we show why the co-evolutionary algorithm works better than SGA in terms of an extended schema theorem. And predator-prey co-evolution and symbiotic co-evolution, typical approaching methods to co-evolution, are reviewed, and dynamic fitness landscape associated with co-evolution is explained. And the experimental results show a co-evolutionary algorithm works well in optimization problems even though in deceptive functions.

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RLDB: Robust Local Difference Binary Descriptor with Integrated Learning-based Optimization

  • Sun, Huitao;Li, Muguo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.9
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    • pp.4429-4447
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    • 2018
  • Local binary descriptors are well-suited for many real-time and/or large-scale computer vision applications, while their low computational complexity is usually accompanied by the limitation of performance. In this paper, we propose a new optimization framework, RLDB (Robust-LDB), to improve a typical region-based binary descriptor LDB (local difference binary) and maintain its computational simplicity. RLDB extends the multi-feature strategy of LDB and applies a more complete region-comparing configuration. A cascade bit selection method is utilized to select the more representative patterns from massive comparison pairs and an online learning strategy further optimizes descriptor for each specific patch separately. They both incorporate LDP (linear discriminant projections) principle to jointly guarantee the robustness and distinctiveness of the features from various scales. Experimental results demonstrate that this integrated learning framework significantly enhances LDB. The improved descriptor achieves a performance comparable to floating-point descriptors on many benchmarks and retains a high computing speed similar to most binary descriptors, which better satisfies the demands of applications.

Field Visit Study of Newly Constructed Supportive Housing 'The Brook' in Decayed Area of New York, USA (쇠퇴지역 내 신축형 서포티브주택의 특성 연구 - 미국 뉴욕시 '더 브룩' 사례를 중심으로 -)

  • Lee, Yeunsook;Park, Jaehyun;Qi, Ting
    • KIEAE Journal
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    • v.16 no.2
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    • pp.43-52
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    • 2016
  • In the 21st century, Korea had radical economic development with accelerating urban sprawl, and following declination with social polarization. City declination makes socially vulnerable people unstable and increase homelessness. The projects revitalizing decayed area utilize local idle spaces to build new facility with creative supportive programs. The purpose of this study is to analyze inclusive characteristics of a supportive housing 'The Brook'. A field visit walk through observation and in-depth interview were utilized as research methods. The information of a representative supportive housing field will promote understanding the concept, and create base for further research. As results, state and knowhow of information concerning housing first policy, active government investment, space planning, management, social integration, service providing, architecture and so on offered to facilitate inclusive insights. In conclusion, the characteristics of supportive housing were realistically analyzed through a field research. This research is significant to introduce initially the effective supportive housing which has been practiced for 30 years in USA to that needs alternatives for the socially vulnerable in Korea.