• Title/Summary/Keyword: quantitative evaluation standards

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Evaluation of Wind-Induced Vibration for Multiple Stacks Using Numerical Analysis (전산 해석을 이용한 다중연돌의 유체유발진동)

  • Yang, Kwangheok;Park, Chaegwan;Kim, Hyeonjoon;Baek, Songyoul;Park, Soontae
    • Plant Journal
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    • v.12 no.3
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    • pp.24-31
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    • 2016
  • Wind-induced vibration is a phenomenon that a struture is oscillated due to wind force such as buffeting, vortex shedding wake and etc., which is one of important characteristics to be considered for design in case that stack has significant slenderness ratio or low natural frequency. International design standards of stack define several criteria for evaluating the suitability of stack design, which describe the required design considerations for each range of design parameters and provide the instruction to verify the stack design against wind-induced vibration simply. However, there is a limitation that they cannot provide quantitative information in case code requirement cannot be satisfied due to constraints of plant space or economical design. In order to overcome the limiation of code, integrated numerical analysis of computational fluid dynamics, harmonic analysis and finite element analysis were proposed to investigate wind-induced vibration for multiple stacks in actual plant. Simulated results of mutual wake interference effect between adjacent stacks were evaluated and compared to the criteria in international standards.

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Methodologies of Qualitative Survey and Analysis for ITS Projects (ITS 사업의 정성적 조사 및 분석 방법론 정립)

  • Choi, Yoon-Hyuk;Choi, Kee-Choo
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.7 no.1
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    • pp.115-126
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    • 2008
  • Since the ITS project of Gwacheon city has been implemented in 1998, feasibility analysis for various ITS projects has been conducted in quantitative and qualitative aspects. However, ITS operation manual that describes the universal standards comprehensive methodology for survey and analysis for the qualitative effects of the ITS. Although it its difficult to measure the qualitative elements, the effectiveness and achievement of ITS project can be directly evaluated from the user survey. A comprehensive methodology proposed in this paper includes the design and implementation of the qualitative survey, the procedure of data analysis, the evaluation, and proposing the enhancements. The proposed methodology that take both quantitative and qualitative aspects into account, therefore, can lead the accurate and effective assessment of ITS projects.

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Business Process Evaluation and Case Study for Sequential Application of BPM

  • Song, Young-Woong;Lim, Hyung-Chul;Choi, Yoon-Ki
    • Journal of Construction Engineering and Project Management
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    • v.2 no.2
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    • pp.36-44
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    • 2012
  • Adoption and practical application of BPM yet remains at a theoretic and methodological level for many industrial sectors. As for construction industry, adapting BPM into enterprise resource across all business processes could cause problems due to rapid change in corporate operation systems. Furthermore, it is unable to predict potential risks of business process while BPM are being applied. Therefore, applying BPM model to core strategy and individual task seems more effective than applying BPM model to the entire enterprise resource planning. In this paper, we define BPM and suggest a BPM model by analyzing each business unit in order to evaluate each business unit which is included in the business process architecture based on quantitative standards. This paper also presents a sequential application plan for business process model. Finally, a case study is demonstrated for the application of BPM system, focusing on cost management business, which turned out to be a top priority in the aspect of efficiency and ease based on priority analysis.

A Study on Reliability Analysis of Electric Railway Catenary System using FMECA (FMECA를 통한 전차선로 가선시스템의 신뢰도 분석에 관한 연구)

  • Youn, Eung-Kyu;Choi, Kyu-Hyoung
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.11
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    • pp.1618-1625
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    • 2015
  • The reliability of catenary system is very important for uninterrupted train operation as it supplies electric power to train without redundant facilities. This paper provides a systematic approach to the reliability analysis of the catenary system based on FMECA procedures defined by global standards such as MIL Std 1692a and IEC 60812. Field failure data collected from the operation and maintenance of high-speed railway catenary system for 9 years are used to derive critical failure modes and to evaluate the criticality of the failure modes. Evaluation of the criticality are carried out by quantitative procedures defined by MIL Std 1692a and by criticality matrix defined by IEC 60812. FMECA results suggests that three critical failure modes should be checked carefully during maintenance work, which include strand break of dropper and voltage equalizing wire, power supply failure of feeder. Maintenance procedure of catenary system in order of importance is suggested too. These results can be applied to maintenance planning and design of catenary system to improve the reliability of electric railway system.

Visualization of Surface Deformation on an Open-Hole Specimen Based on Grating Shearography

  • Lee, Jung-Ryul;Lee, Seung-Seok;Chung, Won-Seok
    • Journal of the Korean Society for Nondestructive Testing
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    • v.27 no.6
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    • pp.563-575
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    • 2007
  • This contribution contained the classical work of an open-hole tensile plate to demonstrate the performance of grating shearography and to compare with the results obtained by other full-field measurement techniques, The isotropic plate with an open-hole has often appeared in the previous contributions introducing novel full-field method and system. Grating shearography directly provided six quantitative measurands about the specimen's surface kinematics by using a single measurement set: three in-plane strains, in plane rotation, and two out-of-plane slopes. The quasi-plane wavefront of grating metrology led to high signal-to-noise ratio (SNR) and thus neither fitting nor filtering was applied, and the small shearing distance of $101{\mu}m$ could be used. The small shearing distance provided the outstanding spatial resolution of $80{\mu}m$ and sensitivity appropriate for experimental mechanics. Finally, the grating shearography enabled the visualization of the complex surface deformation around the hole and also detected parasitic flexions of the specimen in the micrometer regime during the tensile test.

Analyzing the Trends of Development Evaluation in South Korea : Focusing on the Ex-Post Evaluation Reports of KOICA (1998-2016) (한국의 무상원조 평가 동향 연구: KOICA 사후평가 보고서 분석을 중심으로 (1998-2016))

  • Sohn, Hyuk-Sang;Lee, Jinyoung;Yi, Ilcheong
    • Journal of International Area Studies (JIAS)
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    • v.22 no.1
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    • pp.161-202
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    • 2018
  • The purpose of this study is to analyze the ex-post evaluation reports of KOICA's grant aid project in terms of criteria, methods, and contents. To this end, we will examine the evaluation history and process with particular reference to EDCF and KOICA. Our key research questions are: 1) How are the evaluation standards of the OECD DAC reflected in the KOICA ex-post evaluation reports? 2) Whether did Korea's practices of development evaluation change after its entry into the OECD DAC. The paper attempted an content analysis on the key words used in findings and recommendation section of the reports since 1998 that ara available on the website of KOICA. The main results can be summarized as follows. First, the frequency of OECD DAC criteria(relevance, efficiency, effectiveness, impact, sustainability) and the use of quantitative methods have been increasing after joining the OECD DAC. Second, in the ex-post evaluation reports issued after 2010, the reference indices including the Project Design Matrix (PDM), baseline data, and performance have increased exponentially.

Development of dimethyl disulfide gas CRM and stability test (다이메틸다이설파이드 가스 인증표준물질 개발 및 안정성 평가)

  • Kim, Young-Doo;Woo, Jin-Chun;Bae, Hyun-Kil
    • Analytical Science and Technology
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    • v.19 no.6
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    • pp.498-503
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    • 2006
  • A type of dimethyl disulfide gas CRM in the ppb level was developed for the analysis of tracelevel odorous gas in environmental atmosphere. The concentration of dimethyl disulfide($(CH_3)_2S_2$) was $10{\mu}mol/mol$ level in the cylinder filled with nitrogen, 1500 psi. And the variability of the concentration for 2 years was about 0.14% due to the adsorption or instability of $(CH_3)_2S_2$. The gas standards produced simultaneously in 4 bottles and examined by GC-FID were shown with 0.4%, reproducibility of preparation and 0.25%, standard uncertainty due to weighing and purity. The relative expended uncertainty of 1.1%(95% of confidence level, k=2) was assigned to the certified value of $10{\mu}mol/mol$ level of $(CH_3)_2S_2$ after quantitative evaluation on the purity, mixing, weighing, analysis, adsorption and stability of dimethyl sulfide gas.

Complementary measures for Environmental Performance Evaluation Index of External Space of Green Standard for Energy and Environmental Design for Apartment Complex - Focused on the Respect of Response to Climate Change - (공동주택 녹색건축인증기준의 외부공간 환경성능 평가지표 보완방안 - 기후변화 대응 측면을 중심으로 -)

  • Ye, Tae-Gon;Kim, Kwang-Hyun;Kwon, Young-Sang
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.34 no.1
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    • pp.3-14
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    • 2018
  • An apartment complex is a building use with great potential to contribute to solving problems related to urban ecological environment and climate change. The first goal of this study is to grasp the current situation of application and limitations of the ecological area rate, which is a representative evaluation index used to evaluate the environmental performance of the external space of an apartment complex in Green Standard for Energy and Environmental Design (G-SEED). The second goal is to propose a prototype of the evaluation index for evaluating greenhouse gas (GHG) reduction performance in order to supplement the evaluation index for the environmental performance of the external space in terms of response to climate change. We analyzed 43 cases of apartment complexes certified according to G-SEED, which was enforced since July 1, 2010, and found application characteristics of each space type and the limitations of ecological area rate. We analyzed overseas green building certification systems such as LEED and BREEAM that derived implications for supplementing the limitations of ecological area rate, which is focused on the evaluation of soil and water circulation function, and set up a development direction of complementary measures. Through analysis of previous studies, relevant regulations and standards, and technical documents of the manufacturer, the heat island mitigation performance of the pavement and roof surfaces of the apartment complex and the carbon uptake performance of the trees in the apartment complex was selected as parameters to yield the GHG reduction performance of the external space of the apartment complex. Finally, a quantitative evaluation method for each parameter and a prototype of the evaluation index for the GHG reduction performance were proposed. As a result of applying the prototype to an apartment complex case, the possibility of adoption and applicability as an evaluation index of G-SEED were proved.

Objective Evaluation of Sublingual Veins Using Color Differences (색차(色差)값을 활용(活用)한 설하락맥(舌下絡脈)의 정량적(定量的) 평가(評價))

  • Park, Young-Jae;Park, Young-Bae
    • The Journal of Korean Medicine
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    • v.27 no.3 s.67
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    • pp.201-211
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    • 2006
  • Background: Although several efforts have been made recently to grade the severity of sublingual veins, these methods still meet some problems: clinicians' subjectivity and diversity of lighting conditions. Objectives: The purpose of our study was to quantify the severity of sublingual veins using CDs (color differences), and to verify clinical validity of the parameters of sublingual veins using CDs. Methods: We photographed the inferior surface of subjects' tongue from 74 subjects. CDs were computed through two sets of mean $L^*a^*b^*$ values extracted from BRC (black reference color) and the inferior surface of the tongue. We assumed that SVI (sublingual veins index) normalized percentage of a reciprocal of CDs between BRC and the inferior surface of the tongue including sublingual veins and BISV (black index of sublingual veins) percentage of a reciprocal of CDs between BRC and the main trunk of sublingual veins could be applied as quantitative parameters of sublingual veins and examined whether there are meaningful correlations between CDs and subjective grading by the clinicians or not. Results: There were high positive correlations of SVI and BISV to clinician evaluation respectively (r=0.715, 0.634). We computed a multiple regression equation which includes SVI and BISV as independent factors $(r^2=0.60);\;Y=0.711+0.046X_1+0.205X_2$ (Y: the severity of sublingual veins, $X_1:\;SVI,\;X_2:\;BISV$). Conclusions: We conclude that the severity of sublingual veins can be quantified through SVI and BISV, minimizing the clinicians' subjectivity and the diversity of lighting conditions.

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Simulation of Elastic Wave Propagation in Anisotropic Materials (이방성 재료에서의 탄성파 전파 과정에 대한 시뮬레이션)

  • Kim, Young-H.;Lee, Seung-S.
    • Journal of the Korean Society for Nondestructive Testing
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    • v.17 no.4
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    • pp.227-236
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    • 1997
  • Quantitative analysis and imaging of elastic wave propagation are very important for the materials evaluation as well as flaw detection. The elastic wave propagation in an anisotropic media is more complex, and analysis and imaging become essential for flaw detection and materials evaluation. In the anisotropic media, the wave velocity is dependent on the propagation direction. In addition, the direction of group velocity is different from that of phase velocity, the direction of energy flow is not same as the propagation direction of wavefront (beam skewing effect). Especially, this effect becomes critical for the large anisotropic media such as fiber composite materials, and the results using elastic waves for those materials have to be analyzed considering the wave propagation mechanism. Since the analytical approach for the wave propagation in the anisotropic materials is limited, the numerical analysis such as finite difference method (FDM) have been used for these case. Therefore, 2-dimensional FDM program for the elastic wave propagation is developed, and wave propagation in anisotropic media are simulated.

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