• Title/Summary/Keyword: time integration scheme

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An FSI Simulation of the Metal Panel Deflection in a Shock Tube Using Illinois Rocstar Simulation Suite (일리노이 록스타 해석환경을 활용한 충격파관 내 금속패널 변형의 유체·구조 연성 해석)

  • Shin, Jung Hun;Sa, Jeong Hwan;Kim, Han Gi;Cho, Keum Won
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.41 no.5
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    • pp.361-366
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    • 2017
  • As the recent development of computing architecture and application software technology, real world simulation, which is the ultimate destination of computer simulation, is emerging as a practical issue in several research sectors. In this paper, metal plate motion in a square shock tube for small time interval was calculated using a supercomputing-based fluid-structure-combustion multi-physics simulation tool called Illinois Rocstar, developed in a US national R amp; D program at the University of Illinois. Afterwards, the simulation results were compared with those from experiments. The coupled solvers for unsteady compressible fluid dynamics and for structural analysis were based on the finite volume structured grid system and the large deformation linear elastic model, respectively. In addition, a strong correlation between calculation and experiment was shown, probably because of the predictor-corrector time-integration scheme framework. In the future, additional validation studies and code improvements for higher accuracy will be conducted to obtain a reliable open-source software research tool.

Study on the Business Process Modeling scheme using the Context Analysis methodology (상황 분석 방법론을 적용한 효율적 비즈니스 프로세스 모델링 방안에 관한 연구)

  • You, Chi-Hyung;Sang, Sung-Kyung;Kim, Jung-Jae;Na, Won-Shik
    • Journal of Digital Contents Society
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    • v.9 no.4
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    • pp.661-667
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    • 2008
  • The dynamics of business cycles has been changed by the macroscopic economic forces because of the introduction of new technical know-how each year. These the dynamics of business has a significant influence on the investment of enterprise in the information communication field. Today, the most important goal of the IT investment is simply not to lower the production cost any more, but to improve the usefulness for the customers and partners in order to obtain the optimized mass products. Therefore, the enterprises have been concentrating their all abilities on the automation, integration, and optimization of business process using BPM. In addition, they are concentrating their efforts on the business expansion by approaching the technical aspect using RFID application system. However, in order to accomplish a successful enterprise ability, the technical view, business process view, and organization view must be considered together. We suggested the method considering organization view, via the technical element, i.e., RFID system for approaching the business process. Furthermore, we tried the optimization of assignment using Context Analysis methodology and proposed the method to reduce the element with respect to the time, human, and expense by applying the Case Study method that minimizes the iteration times through the transmitted processing procedure and type. The proposed method gave us the expectation that it will bring out the innovative improvement with respect to the time, expense, quality, and customer's satisfaction in the process from the analysis of business process to the analysis and design of system.

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An Analysis of 'One Book's Selected in Twenty Years of 'One Book, One City' Reading Campaigns in the U.S.A. (미국 '한 책, 한 도시' 독서운동 20년과 '한 책'의 분석)

  • Yoon, Cheong-Ok
    • Journal of the Korean Society for Library and Information Science
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    • v.51 no.3
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    • pp.45-64
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    • 2017
  • The purpose of this study is to understand the direction of the community reading campaign in the U.S.A. known as 'One Book, One City' reflected in the books selected for this campaign for the past 20 years in terms of their classification numbers, subject headings, publication dates, and genres. Analyzed are the author and state lists of 'One Book, One City' Reading Promotions Projects available from the website of the LC (Library of Congress) Center for the Books, and bibliographic records of 735 books selected in only one 'One Book' program, accessed from LC OPAC. Major findings include continuing influences of the all-time favorite 'One Book' selections, including To Kill a Mockingbird and the extension of their span of life through The Big Read, preference for the recent publications, importance of P (Literatures and Languages) Class (530 titles, 72.1%) and PS(American Literatures) subclass (307 titles, 57.9%) in the LC Classification Scheme, distribution of books in 43 genres, including domestic fiction, historical fiction, and psychological fiction, etc., the use of 535 unique LC subject headings and much interests in "City and town life" (10 titles) and "World War, 1939-1945" (8 titles), and prominence of subject groups which begin with "African American..." and "Woman..." out of 96 groups of subject headings. It is found that the subjects and focus of the selected books expand from integration, understanding, integrity to human rights, environment, peace, etc. The limitations of this study is that the influence of the selected books and the changes in communities are not properly analyed.

A study on the local development paradigm and strategy in the era of localization (地方化時代의 開發패러다임과 그 開發戰略 硏究)

  • ;;Kang, Hak-Soon;Park, Chan-Suk
    • Journal of the Korean Geographical Society
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    • v.30 no.2
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    • pp.132-145
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    • 1995
  • The Purpose of this study is to integrate two opposite paradigms, (development from above) and (development from below), by means of A. Giddenss (structuration theory) and to provide practical development strategies on the basis of integrated paradigm. The integration of these two opposite paradigms is in fact the internalization of epistemological overcoming of 'dependency', which means the structural transformation of dualistic thinking into monistic thinking that the enlargement of capitalist world-system can be 'development' and it may also be 'dependency'. Therefore the practical main issue of this integrated paradigm results in how peripheral countries should achieve self-reliant and continuous development under the circumstances of dependency. To achieve such development while resisting the growing arrogance of transnational capital, development strategies should be prepared to maker revitalized political community designed to fit a human scale and for the economy to be subordinated to the political will of the community. And at the same time the 'empowerment' of people should be strengthened.

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LISI Repository Development Framework based on J2EE for Interoperability Assessment Information Management (상호운용성 평가 정보 관리를 위한 J2EE 기반의 LISI 저장소 개발 프레임워크)

  • 조정희;정병훈;염근혁
    • Journal of KIISE:Software and Applications
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    • v.31 no.11
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    • pp.1439-1454
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    • 2004
  • Recently, Levels of Information Systems Interoperability (LISI) that are used for assessing the information systems interoperability are defined according to the importance of interoperability among information systems. At that time, it is necessary to the construction of an assessment information repository to store and retrieve the interoperability assessment data efficiently. An LISI repository constructed for storing and retrieving an assessment information should support assessment systems that are developed in various Platforms and provide its functions by a standardized way. Business logics of LISI repository should be developed as distributed components, and we need to modify existing software design methods to show characteristics of LISI repository in addition to the standardized LISI data expression. Also a concrete method to recognize various implementation technologies and to apply them to implementation of LISI repository is needed. This paper provides a design method for developing an LISI repository that is considering the characteristics of LISI repository by three concerns, and an implementation scheme that can apply to the integration of the various repository implementation technologies systematically, as the LISI repository development framework for constructing the LISI repository. These help developers to construct the LISI repository effectively by providing concrete guidelines for considerations and appliable methods to construct the LISI repository.

A Study on Elementary School Students' Understanding of Fractions (초등학생의 분수이해에 관한 연구)

  • 권성룡
    • School Mathematics
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    • v.5 no.2
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    • pp.259-273
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    • 2003
  • A fraction is one of the most important concepts that students have to learn in elementary school. But it is a challenge for students to understand fraction concept because of its conceptual complexity. The focus of fraction learning is understanding the concept. Then the problem is how we can facilitate the conceptual understanding and estimate it. In this study, Moore's concept understanding scheme(concept definition, concept image, concept usage) was adopted as an theoretical framework to investigate students' fraction understanding. The questions of this study were a) what concept image do students have\ulcorner b) How well do students solve fraction problems\ulcorner c) How do students use fraction concept to generate fraction word problem\ulcorner By analyzing the data gathered from three elementary school, several conclusion was drawn. 1) The students' concept image of fraction is restricted to part-whole sub-construct. So is students' fraction understanding. 2) Students can solve part-whole fraction problems well but others less. This also imply that students' fraction understanding is partial. 3) Half of the subject(N=98) cannot pose problems that involve fraction and fraction operation. And some succeeded applied the concept mistakenly. To understand fraction, various fraction subconstructs have to be integrated as whole one. To facilitate this integration, fraction program should focus on unit, partitioning and quantity. This may be achieved by following activities: * Building on informal knowledge of fraction * Focusing on meaning other than symbol * Various partitioning activities * Facing various representation * Emphasizing quantitative aspects of fraction * Understanding the meanings of fraction operation Through these activities, teacher must help students construct various faction concept image and apply it to meaningful situation. Especially, to help students to construct various concept image and to use fraction meaningfully to pose problems, much time should be spent to problem posing using fraction.

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A scheme on strengthening of R.O.K reserved force (예비전력 정예화 방안)

  • Kim, Jae-Sam
    • Journal of National Security and Military Science
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    • s.5
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    • pp.1-45
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    • 2007
  • Reserved forces of ROKA are in charge of replacement of TOE in the wartime and mission of rear area operation. But there is institutional inertia in the law and organization oriented to fill human resources rather than take mission. We need to prepare for the investment and arrangement of reserved forces as military power that would be replaced standing forces. In this portion, to reinforce reserve forces elite, First, efficient mobilization regulations and systems are suggested. I covered a maintenance of relevant mobilization ordinances which need to legislated and approved by national assembly for wartime and development of mobilization system which might lose the appropriate time for mobilization due to complicated declaration procedures and measures to overcome the panic at the initial stage of the war and organization and employment of nationwide transportation system and mobilization center. To ensure efficient resource management and mobilization of reserve forces with a number of approximately 3 million, there's a necessity of organization for integration and conciliation. To make it real, I suggested establishing and employing the mobilization center, on first phase, employ the mobilization center focusing on homeland divisions, on second phase, it is advisable to convert to national level mobilization system and develop to central mobilization center focusing on national emergency planning committee. During peacetime, in conjunction with Mobilization Cell, mobilization center can conduct resource survey and integrate and manage mobilization resources and take charge of mobilization training of subordinate units, and during wartime, in conjunction with mobilization coordination team and Cell, can ensure the execution of mobilization. Second, Future oriented reserve forces management system such as service system of reserve forces and support system of homeland defense operations. Current service and trainings of reserve forces by the year have very low connection, as it is very complex to manage the resources and trainings, and service and training lack the equity, re-establishment of service system is required. Also in an aspect of CSS and cultivation support for reserve forces, as the scope and limitation of responsibility between the armed forces and autonomous organization is obscure, conditions to conduct actual-fighting exercises are limited. Concentrated budgetting is extremely difficult because reserve forces training fields are scattered nationwide, and facilities and equipments are rapidly getting older. To improve all these, I suggest the organization of homeland defense battalion with a unit of "City-Gun-District" and supporting the local reserve forces. Conduct unit replacement or personal replacement for those who have finished their 1 or 2 years and homeland defense operation duty for those with 3-5 years for consistency and simplification. Third, I suggest Future oriented Reserved Training(FRT) and Training Center oriented training management to establish a reliable reserve training. Reserves carry out expansion of unit, conventional combat mission, homeland defense and logistics support during wartime, and actual-fighting exercise, and disaster relief, peace keeping activities. Despite diverse activities and roles, their training condition still stays definitely poor. For these reasons, Modernization of weapons and facilities through gradual replacement and procurement is essential to enhance mobilization support system.

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Digitalization of the Nuclear Steam Generator Level Control System (증기발생기 수위조절 시스템의 디지탈화)

  • Lee, Yoon-Joon;Lee, Un-Chul
    • Nuclear Engineering and Technology
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    • v.25 no.1
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    • pp.125-135
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    • 1993
  • The safe and efficient operation of nuclear plants is recognized to be accomplished through the application of plant automation using digital technology, which is one of main targets of the next generation nuclear plants. For plant level automation, it is first required that each major subsystem be digitalized, and the steam generator water level control system is discussed in this study. The transfer functions between inputs and the level are derived by employing the thermal hydraulic model of the steam generator and are applied to the analysis of the current three-element control system. Since the control scheme in this study includes the steam generator itself as a process plant, the system order is high and the numerical instability arises in digitalizing. Together with this, the unreliability of the feedwater feedback signal at low power level leads to the proposal of a two-element control system with a proper digital controller. The digital PI controller developed for this system has the initial power adaptive gain and integration time constant. And it makes the overall system response satisfy the stability and other necessary control specifications simultaneously. Since the two-element control system using this controller depends on the initial power only, it is simple to define and it shows a similar level response behavior to that of its corresponding analog system.

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Development of Multimedia Annotation and Retrieval System using MPEG-7 based Semantic Metadata Model (MPEG-7 기반 의미적 메타데이터 모델을 이용한 멀티미디어 주석 및 검색 시스템의 개발)

  • An, Hyoung-Geun;Koh, Jae-Jin
    • The KIPS Transactions:PartD
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    • v.14D no.6
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    • pp.573-584
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    • 2007
  • As multimedia information recently increases fast, various types of retrieval of multimedia data are becoming issues of great importance. For the efficient multimedia data processing, semantics based retrieval techniques are required that can extract the meaning contents of multimedia data. Existing retrieval methods of multimedia data are annotation-based retrieval, feature-based retrieval and annotation and feature integration based retrieval. These systems take annotator a lot of efforts and time and we should perform complicated calculation for feature extraction. In addition. created data have shortcomings that we should go through static search that do not change. Also, user-friendly and semantic searching techniques are not supported. This paper proposes to develop S-MARS(Semantic Metadata-based Multimedia Annotation and Retrieval System) which can represent and extract multimedia data efficiently using MPEG-7. The system provides a graphical user interface for annotating, searching, and browsing multimedia data. It is implemented on the basis of the semantic metadata model to represent multimedia information. The semantic metadata about multimedia data is organized on the basis of multimedia description schema using XML schema that basically comply with the MPEG-7 standard. In conclusion. the proposed scheme can be easily implemented on any multimedia platforms supporting XML technology. It can be utilized to enable efficient semantic metadata sharing between systems, and it will contribute to improving the retrieval correctness and the user's satisfaction on embedding based multimedia retrieval algorithm method.

Evaluating Impact Resistance of Externally Strengthened Steel Fiber Reinforced Concrete Slab with Fiber Reinforced Polymers (섬유 보강재로 외부 보강된 강섬유 보강 콘크리트 슬래브의 충격저항성능 평가)

  • Yoo, Doo-Yeol;Min, Kyung-Hwan;Lee, Jin-Young;Yoon, Young-Soo
    • Journal of the Korea Concrete Institute
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    • v.24 no.3
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    • pp.293-303
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    • 2012
  • Recently, as construction technology improved, concrete structures not only became larger, taller and longer but were able to perform various functions. However, if extreme loads such as impact, blast, and fire are applied to those structures, it would cause severe property damages and human casualties. Especially, the structural responses from extreme loading are totally different than that from quasi-static loading, because large pressure is applied to structures from mass acceleration effect of impact and blast loads. Therefore, the strain rate effect and damage levels should be considered when concrete structure is designed. In this study, the low velocity impact loading test of steel fiber reinforced concrete (SFRC) slabs including 0%~1.5% (by volume) of steel fibers, and strengthened with two types of FRP sheets was performed to develop an impact resistant structural member. From the test results, the maximum impact load, dissipated energy and the number of drop to failure increased, whereas the maximum displacement and support rotation were reduced by strengthening SFRC slab with FRP sheets in tensile zone. The test results showed that the impact resistance of concrete slab can be substantially improved by externally strengthening using FRP sheets. This result can be used in designing of primary facilities exposed to such extreme loads. The dynamic responses of SFRC slab strengthened with FRP sheets under low velocity impact load were also analyzed using LS-DYNA, a finite element analysis program with an explicit time integration scheme. The comparison of test and analytical results showed that they were within 5% of error with respect to maximum displacements.