• Title/Summary/Keyword: standard definition

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Allocation of Safety Integrity Level for Railway Platform Screen Door System based on Consequence Severity and Risk Graph (결과 심각도 및 리스크 그래프에 기반한 철도 승강장 도어시스템의 안전 무결성 수준 할당)

  • Song, Ki Tae;Lee, Sung Ill
    • Journal of the Korean Society of Safety
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    • v.30 no.6
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    • pp.164-173
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    • 2015
  • There exists required safety integrity level (SIL) to assure safety in accordance with international standards for every electrical / electronics / control equipment or systems with safety related functions. The SIL is allocated from lowest level (level 0) to highest level (level 4). In order to guarantee certain safety level that is internationally acceptable, application of methodology for SIL allocation and demonstration based on related international standards is required. However, application standard differs from every industry in domestic or international for application on mythology for allocation and demonstration of SIL. Application or assessment is not easy since absence on clear criteria or common definition. This research studied not only fundamental concept of SIL required to guarantee safety in accordance with international standards for safety related equipment and system, but different types of methodologies for SIL allocation. Specifically, SIL allocation for Platform Screen Door system of railway is studied applying methodology of severity of accidents and risk graph among different methodologies for SIL allocation.

A Shared Inlining Method for Resolving the Overlapping Problem of Elements (엘리먼트의 중첩 문제를 해결한 Shared Inlining 저장 기법)

  • Hong, Eun-Il;Lee, Young-Ho
    • Journal of KIISE:Databases
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    • v.35 no.5
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    • pp.411-420
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    • 2008
  • The number of XML documents, which are widely used as a standard method for information expression and exchange in the web-based environment, increases rapidly along with the growing production of large XML documents. Many studies have been made to store and retrieve these XML documents on RDBMS, among which Shared Inlining storage method has a higher level of retrieval efficiency. The Shared Inlining method is the technique that analyzes the DTD information and stores the XML document in RDBMS by dividing for each node component. This study proposes the technique to resolve the overlapping problem that occurs in the element with several child nodes in the existing Shared Inlining method. The suggested method stores the XML document in the Shared Inlining structures appropriate to the DTD definition and enhances the accuracy of retrieval.

The Importance and Categorization of Task Elements of School Food Service Dietician (학교급식 영양사의 업무 중요도 및 임무차원 분석)

  • 이영은;양일선;차진아
    • Journal of Nutrition and Health
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    • v.35 no.6
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    • pp.668-680
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    • 2002
  • The purpose of this study was to investigation the importance and categorization of task elements of school food service dietician and to provide the useful data for standard model of the dietician′s tasks of school foodservice. This study was conducted in school food services nationwide in method of written questionnaire. The questionnaires were mailed to the dieticians of 3 type school foodservice system-conventional, commissary, joint management. Of the 660 schools that participated in this study, the responses from 212 conventional system and 212 commissary system and 200 joint management system were selected for analysis. Statistical analysis was performed with SAS/Win 6.12 package program for descriptive analysis, T-test, ANOVA, factor analysis using. The main results of this study can be summarized as follows Importance level was more than 4 score out of 5 scale in most of the task elements. The result was indicative of the appropriateness of definition of the 61 task elements. Of 61 task elements, importance level on ′nutrition education′ and on ′evaluation of foodservice operation management′ indicated the most significant difference between present and ideal situation. Through factor analysis, 61 task elements were regrouped into 7 dimensions; "Duty dimension of cooking and distribution management", "Duty dimension of cost management", "Duty dimension of raw material management", "Duty dimension of education management", "Duty dimension of menu management", "Duty dimension of record keeping of foodservice", "Duty dimension of general management (others)".

A Study on the Uncertainty of the Classification of Rook Mass Rating (RMR 암반분류법의 불확정성에 관한 연구)

  • Lee Sang-Eun;Jun Sung-Kwon;Kang Sang-Jin
    • Tunnel and Underground Space
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    • v.15 no.6 s.59
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    • pp.441-451
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    • 2005
  • It is the unavoidable problem that the RMR rock classification method has the uncertainty resulted from uncertain definition of measured value in RMR grade table, hence in this paper, the estimation of probability density function$(p{\cdot}d{\cdot}f)$ graph with the evaluation of continuos RMR and the Monte Carlo Simulation and statistic reasoning were carried out to evaluate the uncertainty quantitatively. Also, the modified RMR rock classification table was presented in order to apply the uncertainty of RMR to the practice, and then the design process of standard support pattern and the tunnel support material was proposed.

A Middleware Based Architecture for the Industrial Internet of Things

  • Ungurean, Ioan;Gaitan, Nicoleta Cristina;Gaitan, Vasile Gheorghita
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.7
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    • pp.2874-2891
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    • 2016
  • Due to its potential, the Internet of Things (IoT) begins to be used in the industrial field. Nevertheless, although the concept called the Industrial Internet of Things does not know a widely accepted definition, it is based on the existing technology, and introduces the IoT in the industrial environment through the compliance with specific additional requirements and by integrating various fieldbuses with distinctive features, from the real-time point of view. The aim of this paper is to propose a practical architecture for the Industrial Internet of Things. The proposed architecture is designed around the Data Distribution Service for Real Time System (DDS) middleware protocol, and it is organized on four levels. Between these levels, it is defined standard interface, and they can be developed independently. For this reason, the architecture is scalable because at the middleware level, the DDS can be replaced by other middleware systems. At the final, it is performed a comparison between several middleware systems used in the proposed architecture.

Reference Points Selection for Interpolation in Digital Elevation Model (수치표고모델의 보간기준점 선정에 관한 연구)

  • 최병길;김욱남;진세일
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.21 no.2
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    • pp.131-136
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    • 2003
  • The method that selects reference points for interpolation is very important in Digital Elevation Model. However, there is no definition of an accurate standard until now, so users select the reference points for interpolation at their option. This paper aims to study on the accurate selection of the reference points for interpolation of DEM. This paper analyzed the method using the number of points and the reference points selection method by using the average distance calculated, from irregular points. Based on the analysis of the results, it shows that the Kriging method applying of the average distance is more efficient in construction of DEM.

The Development of A Standardized Test of Science Inquiry Skills : Interpreting and Analyzing Data for Eighth Grade Students (과학 탐구능력 측정을 위한 표준화 검사지 개발 - 중학교 2학년의 자료 분석과 해석 능력을 중심으로 -)

  • Lee, Youne-Woo;Woo, Jong-Ok
    • Journal of The Korean Association For Science Education
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    • v.11 no.1
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    • pp.59-72
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    • 1991
  • This study has formed a clear definition of the elements of inquiry skills : inference, determining relationship, causal explanation, prediction, and created the goals of assessment and the items of assessment. They have been checked the validity and the objectivity and the clarity of the items by six professors of science education. At the same time, the two times of the field trial has been executed. and checked the discriminating power and the difficulty index and the effectiveness of distracters, and modified the items. The test developed in this way was administered to 1060 students of the eighth grade, randomly cluster-sampled from the universe, and standardized. The test is the aptitude test as well as the norm-reference test. and has twenty items. The testing-time is thirty minutes. And the cotent validity is 85%, the objectivity of the answer keys 91.7%, the mean of items difficulty 68.8%, the mean of discriminating power 0.39, the standard deviation 3.31, the reliability(K-R 20) 0.69. Because it is the standardized lest, it can diagnose the well-developed skills and the ill-developed skills of the students, and monitor the development of skills.

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A Study on the y+ Effects on Turbulence Model of Unstructured Grid for CFD Analysis of Wind Turbine (풍력터빈 전산유체역학해석에서 비균일 그리드 무차원 연직거리의 난류모델에 대한 영향특성)

  • Lee, Kyoung-Soo;Ziaul, Huque;Han, Sang-Eul
    • Journal of Korean Association for Spatial Structures
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    • v.15 no.1
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    • pp.75-84
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    • 2015
  • This paper presents the dimensionless wall distance, y+ effect on SST turbulent model for wind turbine blade. The National Renewable Energy Laboratory (NREL) Phase VI wind turbine was used for the study, which the wind tunnel and structural test data has publicly available. The near wall treatment and turbulent characteristics have important role for proper CFD simulation. Most of the CFD development in this area is focused on advanced turbulence model closures including second moment closure models, and so called Low-Reynolds (low-Re) number and two-layer turbulence models. However, in many cases CFD aerodynamic predictions based on these standard models still show a large degree of uncertainty, which can be attributed to the use of the $\epsilon$-equation as the turbulence scale equation and the associated limitations of the near wall treatment. The present paper demonstrates the y+ definition effect on SST (Shear Stress Transport) turbulent model with advanced automatic near wall treatment model and Gamma theta transitional model for transition from lamina to turbulent flow using commercial ANSYS-CFX. In all cases the SST model shows to be superior, as it gives more accurate predictions and is less sensitive to grid variations.

A Study on the Electronic Reference Services Using Electronic Bulletin Boards in University Libraries (전자게시판을 이용한 대학도서관의 참고정보저비스에 관한 연구 -자유게시판, Q&A, FAQ, 참고질의응답을 중심으로-)

  • 이명희;이미영
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.14 no.2
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    • pp.159-178
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    • 2003
  • Electronic reference service was defined as reference service designed for remote users and identified by a specific link from a library' website. This study examined whether academic libraries deliver web-based electronic reference services to remote users. Particularly, four types of electronic bulletin board services, free bulletin board, FAQ, Q&A and reference question-response service were measured in terms of 8 types of questions and 12 contents of questions. The result showed that there was few differences among 4 services. Guidelines for effective use of electronic bulletin board services in academic libraries were suggested: standardization of service names, easy access to menu services, definition of each menu, search function for contents and standard web forms.

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Implementation of a macro model to predict seismic response of RC structural walls

  • Fischinger, Matej;Isakovic, Tatjana;Kante, Peter
    • Computers and Concrete
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    • v.1 no.2
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    • pp.211-226
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    • 2004
  • A relatively simple multiple-vertical-line-element macro model has been incorporated into a standard computer code DRAIN-2D. It was used in blind predictions of seismic response of cantilever RC walls subjected to a series of consequent earthquakes on a shaking table. The model was able to predict predominantly flexural response with relative success. It was able to predict the stiffness and the strength of the pre-cracked specimen and time-history response of the highly nonlinear wall as well as to simulate the shift of the neutral axis and corresponding varying axial force in the cantilever wall. However, failing to identify the rupture of some brittle reinforcement in the third test, the model was not able to predict post-critical, near collapse behaviour during the subsequent response to two stronger earthquakes. The analysed macro model seems to be appropriate for global analyses of complex building structures with RC structural walls subjected to moderate/strong earthquakes. However, it cannot, by definition, be used in refined research analyses monitoring local behaviour in the post critical region.