• Title/Summary/Keyword: supra-convergence

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A REVIEW OF THE SUPRA-CONVERGENCES OF SHORTLEY-WELLER METHOD FOR POISSON EQUATION

  • Yoon, Gangjoon;Min, Chohong
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.18 no.1
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    • pp.51-60
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    • 2014
  • The Shortley-Weller method is a basic finite difference method for solving the Poisson equation with Dirichlet boundary condition. In this article, we review the analysis for supra-convergence of the Shortley-Weller method. Though consistency error is first order accurate at some locations, the convergence order is globally second order. We call this increase of the order of accuracy, supra-convergence. Our review is not a simple copy but serves a basic foundation to go toward yet undiscovered analysis for another supra-convergence: we present a partial result for supra-convergence for the gradient of solution.

THE GENERALIZED OPEN SETS ON SUPRATOPOLOGY

  • Min, Won Keun
    • Korean Journal of Mathematics
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    • v.10 no.1
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    • pp.25-28
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    • 2002
  • We introduce the notion of $s{\gamma}$-sets, and we investigate some properties of $s{\gamma}$-sets. In particular, we characterize the $s{\gamma}$-closure by terms of supra-convergence of filters.

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A Numerical Study on Efficiency and Convergence for Various Implicit Approximate Factorization Algorithms in Compressible Flow Field. (다양한 근사인수분해 알고리즘을 이용하여 압축성 유동장의 수렴성 및 유용성에 대한 연구)

  • Gwon Chang-O;Song Dong-Ju
    • 한국전산유체공학회:학술대회논문집
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    • 1999.11a
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    • pp.17-22
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    • 1999
  • Convergence characteristics and efficiency of three implicit approximate factorization schemes(ADI, DDADI and MAF) are examined using 2-Dimensional compressible upwind Navier-Stokes code. Second-order CSCM(Conservative Supra Characteristic Method) upwind flux difference splitting method with Fromm scheme is used for the right-hand side residual evaluation, while generally first-order upwind differencing is used for the implicit operator on the left-hand side. Convergence studies are performed using an example of the flow past a NACA0012 airfoil at steady transonic flow condition, i. e. Mach number 0.8 at $1.25^{\circ}$ angle of attack. The results were compared with other computational results in order to validate the current numerical analysis. The results from the implicit AF algorithms were compared well in low surface with the other computational results; however, not well in upper surface. It might be due to lack of the grid around the shock position. Because the algorithm minimizes the errors of the approximate decomposition, the improved convergence rate with MAF were observed.

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Research on Visual Function Before and After Prescription of Vertical Prism (수직사위 교정 전·후 시기능 변화에 대한 연구)

  • Kim, So-ra;Lee, Gi-yung;Park, Hyun-ju
    • Journal of Korean Ophthalmic Optics Society
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    • v.20 no.2
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    • pp.229-235
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    • 2015
  • Purpose: This study was undertaken to study on visual function before and after prescription of vertical prism. Methods: 80 subjects (10-30ages) who had been precribed vertical prism and 1 year after they were represcribed vertical prism. Results: Phoria (p=0.000), supra vergence (p=0.000), NPC (p=0.003), NPA (right eye) (p=0.005), NPA(left eye) (p=0.000) showed a significant change. Conclusion: Vertical prism prescription was reduced during revisit. Supra vergence, NPC, NPA(right eye), NPA(left eye) showed a significant change. Binocular Accommodative lag was not associated with vertical prism prescription and binocular vision findings.

A Study of Policy Conversion in the EU Member States: with Special References to Minimum Income Guarantee (유럽연합의 정책 수렴에 대한 연구: 기초소득 보장을 중심으로)

  • Moon, Jin Young
    • 한국사회정책
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    • v.25 no.1
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    • pp.321-343
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    • 2018
  • This paper aims to apply the convergence theory into the minimum income guarantee which forms the moral foundation of the welfare state. The research question of this paper is if the level of minimum income guarantee among EU member states (EU-15) gradually converging into a certain level. For this purpose, Chapter 2 describes the convergence and diversion of welfare states since the Second World War, and chapter 3 explains the historical development of the EU social policies since the Rome Treaty (1957). Chapter 4, which is the main body of this paper, analyzes if the level of minimum income guarantees of EU member states is converging by the coefficient of variation analysis and regression analysis. However, converging trend of the level of basic income guarantee among EU member states has not been proved. In other words, social policy arena still remains strongly in the realm of national sovereign states, irrespective of growing pressure from the supra-national governing body like the EU. It is in line with the Abram de Swaan's argument that "welfare states is nation states" (1994: 110).

How to Identify Critical Nodes of National Infrastructure Systems in Megacities (메가시티 국가기반체계의 핵심노드 식별 방법)

  • Sim, Jun Hak;Jang, chan Kyu;Park, Sung Jun;Kim, Ki Won;Cho, Sang Keun;Park, Sang Hyuk
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.6
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    • pp.531-536
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    • 2022
  • Megacities are emerging all over the world and gradually becoming the center of an country. Therefore, Megacities are inevitably exposed to various threats such as existing, potential, supra-national, and non-military. In particular, as seen in the recent Ukraine-Russia war, national infrastructure systems has become a major target of enemies. However, considering the size of Megacities, various types of threats, and limited resources, it is impossible to completely protect all national infrastructure systems. Therefore, wisdom is necessary to identify and protect critical nodes. The critical node is the vital point to which the national infrastructure is connected. To this end, in this study, as a method for logically and systematically identifying critical nodes, Node centrality analysis method, which is a network theory, and the Center of Gravity analysis method, which is a military theory, were presented.

Development of Quality Assurance Software for $PRESAGE^{REU}$ Gel Dosimetry ($PRESAGE^{REU}$ 겔 선량계의 분석 및 정도 관리 도구 개발)

  • Cho, Woong;Lee, Jaegi;Kim, Hyun Suk;Wu, Hong-Gyun
    • Progress in Medical Physics
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    • v.25 no.4
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    • pp.233-241
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    • 2014
  • The aim of this study is to develop a new software tool for 3D dose verification using $PRESAGE^{REU}$ Gel dosimeter. The tool included following functions: importing 3D doses from treatment planning systems (TPS), importing 3D optical density (OD), converting ODs to doses, 3D registration between two volumetric data by translational and rotational transformations, and evaluation with 3D gamma index. To acquire correlation between ODs and doses, CT images of a $PRESAGE^{REU}$ Gel with cylindrical shape was acquired, and a volumetric modulated arc therapy (VMAT) plan was designed to give radiation doses from 1 Gy to 6 Gy to six disk-shaped virtual targets along z-axis. After the VMAT plan was delivered to the targets, 3D OD data were reconstructed from 512 projection data from $Vista^{TM}$ optical CT scanner (Modus Medical Devices Inc, Canada) per every 2 hours after irradiation. A curve for converting ODs to doses was derived by comparing TPS dose profile to OD profile along z-axis, and the 3D OD data were converted to the absorbed doses using the curve. Supra-linearity was observed between doses and ODs, and the ODs were decayed about 60% per 24 hours depending on their magnitudes. Measured doses from the $PRESAGE^{REU}$ Gel were well agreed with the TPS doses at central region, but large under-doses were observed at peripheral region at the cylindrical geometry. Gamma passing rate for 3D doses was 70.36% under the gamma criteria of 3% of dose difference and 3 mm of distance to agreement. The low passing rate was resulted from the mismatching of the refractive index between the PRESAGE gel and oil bath in the optical CT scanner. In conclusion, the developed software was useful for 3D dose verification from PRESAGE gel dosimetry, but further improvement of the Gel dosimetry system were required.

A Study of Global Impact on Welfare State : with Special References to the Social Policy of EU (지구화시대 초국가적 권위체가 복지국가 체제에 미치는 영향에 관한 연구 : 유럽연합의 사회정책을 중심으로)

  • Moon, Jin-Young
    • Korean Journal of Social Welfare
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    • v.53
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    • pp.311-336
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    • 2003
  • This paper purports to explain the conflicts and compromises between supra-national authority and national welfare state in an era of globalization. For this purpose this paper, first of all, examines if Community law(EU) is directly applicable to member states(direct applicability), and subsequently, if Community law is superior to national law(supremacy). It duly claims that Community law is de facto applicable to member states and thus is superior to national law, but de jure the direct applicability and supremacy of Community law are still ambiguous in practice. Secondly, it briefly describes the development of EU social policy from 'The Rome Treaty(1957)' to 'The Amsterdam Treaty(1997)', and ascertains clear limitations of social dimension of EU. Thirdly, it explains why CEU(Commission of European Union) sequently fails to achieve uniform harmonization policy in the making of social Europe. This paper concludes that 'downward harmonization thesis' or 'convergence thesis' which commonly stresses that globalization seriously impinges on nation-state's policy autonomy and policy capacity is not evidenced at least in the case of EU social policy.

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The Development of National Competency Standard(NCS) Regarding Casino Operations Management (카지노운영관리 직무에 관한 국가직무능력표준(NCS) 개발)

  • Kim, Dong-Yeon;Oh, Seung-Gyun;Koo, Ja-Gil;Kim, Jinsoo
    • 대한공업교육학회지
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    • v.39 no.1
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    • pp.143-163
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    • 2014
  • This study developed a National Competency Standard(NCS) regarding the casino operations management based on the manual for developing National Competency Standard of 13 years and a revised classification system chart of the National Competency Standard. For the research method, this study developed a national competency standard of relevant jobs after going through review, consultation, modification, supplementation, and reporting procedures 10 times with development experts of the National Competency Standard, the industrial setting professionals, education and training experts, qualification(job analysis) experts, facilitators, and a working group of job verification committee based on the phased range and DACUM procedure of study. The major development results of this study are as follows. First, this study selected and defined duties based on the revised classification system chart of the National Competency Standard, then drew and developed total 8 ability units based on the applicable duties. Secondly, based on the developed ability units, total 27 ability unit factors were deduced and developed. Thirdly, a standard system by ability unit factor was developed based on the level of the national competency standard and revised classification system chart, then this study deduced and developed a supra-domain of the standard system by competency units using the standard tranquility value by these competency unit factors. Based on such development contents and guidelines for the national competency standard ability unit classification number, this study deduced and developed category numbers by relevant competency unit. Fourthly, total 27 relevant performance standard by competency units and knowledge, skill, and attitude were deduced and developed. Fifthly, this study deduced and developed a scope of application, work situation, evaluation guide, core competency, and development history in reference to the total 8 relevant competency units based on the duties.