• Title/Summary/Keyword: similar theory

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Measurement of Two-Dimensional Skin Friction Distribution Using the Overall Fringe Images (간섭영상을 이용한 이차원 표면전단응력 분포 측정에 관한 연구)

  • Lee Han-Sang;Lee Yeol;Yoon Woong-Sup
    • Journal of the Korean Society of Propulsion Engineers
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    • v.10 no.2
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    • pp.87-94
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    • 2006
  • An experimental research program providing knowledge to measure two-dimensional skin friction variation over a certain region of model surface is presented. In the oil-fringe imaging skin friction(FISF) technique, local slope of a thin oil applied on a test surface is measured from the interference fringe patterns on the oil surface, and its information is then related to the applied shear over the oil by the thin-oil lubrication theory. The FISF technique has been applied for a separation flowfield ahead of a circular cylinder vertically mounted on a flat plate, and it has been found that the FISF skin friction results show good comparison with the other numerical/experimental data obtained for similar conditions. implying an applicability of the technique.

Search for Dormant Comets in the Infrared Asteroidal Catalog

  • Kim, Yoonyoung;Ishiguro, Masateru;Usui, Fumihiko
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.1
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    • pp.67.2-67.2
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    • 2014
  • Comet nucleus is a solid body consisting of dark dust grains and ice. Cometary volatiles sublimate from subsurface layer by solar heating, leaving behind large dust grains on the surface. Eventually, the appearance could turn into asteroidal rather than cometary. It is, therefore, expected that there would be "dormant comets" in the list of known asteroids. Our research group has undertaken the research on the population of dormant comets. We applied a brand-new asteroidal catalog compiled from data garnered by three infrared astronomical observatories, AKARI, IRAS and WISE. We extracted objects which have comet-like orbits on the basis of their orbital properties (Tisserand parameters with respect to Jupiter, TJ, and aphelion distance, Q). We found that (1) there are a considerable number (>100) of asteroids in comet-like orbits, and (2) 80% of them have low albedo consistent with comets. This result suggest that these low albedo objects could be dormant comets. One unanticipated finding is that 20% of asteroids in comet-like orbit have high albedo similar to S-type asteroids. It is difficult to explain the population of S-type asteroids in comet-like orbits by the classical mechanics theory. We further found that these high-albedo objects are small (D < 2 km) bodies distributed in near-Earth space. We suggest that such high-albedo, small, near-Earth asteroids are susceptible to Yarkovsky effect and injected into comet-like orbits.

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A Study on the French Modernist Garden of the 1920-30s and Cubisum (1920-30년대 프랑스 모더니즘 정원과 큐비즘)

  • 이상민;조정송
    • Journal of the Korean Institute of Landscape Architecture
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    • v.27 no.5
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    • pp.150-160
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    • 2000
  • The french modernist garden of the 1920-30s, significant when studying the history of gardens, has been disregarded in landscape architecture studies. This study aims to review and examine the main characteristics of the French modernist garden in relation to Cubism. In addition this study seeks to recover an unnoticed phase from landscape architecture history and lies in a same thread with studies on the theory of Modernism in landscape architecture. The french modernist garden is closely connected with Cubism, as Cubist garden is a popular synonym for the French modernist garden. used simplified and geometrical forms like Cubist painters. In spacial composition, the French modernist garden offered images of various views in one space, much like the Cubist paintings which showed various aspects of an object simultaneously on the canvas. In the French modernist garden, gorgeous colors and various textures were emphasized, much like the synthetic Cubism. Moreover, in the history of landscape architecture, the state of the French modernist garden which tried to change the traditional gardens into a space more suited to the new life style, is similar to that of Cubism as an art movement in the history of art of the early 20th century.

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Vector Control of Single Phase Induction Motor for Variable Speed Drive (가변속 구동을 위한 단상 유도전동기의 벡터제어)

  • Lee, Deuk-Kee;Lee, Kyung-Joo;Jung, Jong-Jin;Kim, Heung-Geun
    • Proceedings of the KIEE Conference
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    • 2000.07b
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    • pp.1260-1263
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    • 2000
  • Vector control of a single phase induction machine(SPIM) is usually employed by mechanical methods than electrical ones. The disadvantage of a SPIM has large noise at the starting. Using auxiliary winding which is only utilized for starting, the SPIM can be controlled with the vector control method. Regarding a auxiliary winding one phase, the SPIM is analyzed by the unsymmetrical two phase motor and phase transformation is unnecessary such as three phase IM. Including a auxiliary winding, SPIM is modeled by mathematical getting by component of turns ratio with main to auxiliary winding. It will be take with complicated resultant formula, by comparison to symmetrical three phase TM. For using the vector control theory, it must be decoupled of rotor flux and torque component. stator current is controlled and decoupled. This paper presents a variable-speed control system of SPIM, which to decoupled with flux and torque component and to use machine equivalent circuit referred to rotor, conventionally three phase IM by similar method.

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A Plan of Project Information Management through Analysis of Drafting Process for Transportation Planning (양중계획입안 프로세스의 구조화를 통한 프로젝트 정보관리 방안)

  • Kim, Jin-Ho
    • Journal of the Korea Institute of Building Construction
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    • v.8 no.3
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    • pp.101-109
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    • 2008
  • As the number of high-rise building construction projects grows up, the subject of the transportation planning has become one of the grave issue. however important decision making are made by the experience of the a planner without the rational plans for information sharing. therefore, the purpose of this study is to suggest a plan of prefect information management not only for describing drafting process for transportation planning but also for systematizing information used in the procurement, transportation and construction phase to achieve these objectives, this study 1)analyzes the prior theory about transportation planning, 2)performs a case study of actual project to embody the problems of site management by analyzing the results of interviewing experts. In conclusion, the following factors are systematized : 1)the structure of drafting process for transportation planning, 2)the contents of information used in the procurement, transportation and construction phase, 3)the actual condition of code breakdown structure in transportation Planning phase. It is anticipated that the proposed methodology would be able to improve information management among the related engineers and accumulated data that might be used in similar construction projects in Korea.

Development of a Web-Based Remote Monitoring System for Evaluating Degradation of Machine Tools Using ART2 (ART2 신경회로망을 이용한 공작기계의 웹기반 원격 성능저하 모니터링 시스템 개발)

  • Kim, Cho-Won;Choi, Kook-Jin;Jung, Sung-Hwan;Hong, Dae-Sun
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.18 no.1
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    • pp.42-49
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    • 2009
  • This study proposes a web-based remote monitoring system for evaluating degradation of machine tools using ART2(Adaptive Resonance Theory 2) neural network. A number of studies on the monitoring of machine tools using neural networks have been reported. However, when normal condition is changed due to factors such as maintenance, tool change etc., or a new failure signal is generated, such algorithms need to be entirely retrained in order to accommodate the new signals. To cope with such problems, this study develops a remote monitoring system using ART2 in which new signals when required are simply added to the classes previously trained. This system can monitor degradation as well as failure of machine tools. To show the effectiveness of the proposed approach, the system is experimentally applied to monitoring a simulator similar to the main spindle of a machine tool, and the results show that the proposed system can be extended to monitoring of real industrial machine tools and equipment.

Management and Curricular Components of Pharmacy Residency Programs in Korean Hospitals (우리나라 종합병원에서 실시되고 있는 전문약사과정의 운영 및 교육과정 현황)

  • Park, Sun-Young;Choi, Hye-Yoon;Nagaya-Sriraman, Santoshkumar;Yong, Chul-Soon;Yoo, Bong-Kyu
    • YAKHAK HOEJI
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    • v.53 no.4
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    • pp.165-172
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    • 2009
  • Pharmacy residency program in Korea was first implemented in Seoul National University Hospital in 1983 to train hospital pharmacists regarding theories and practice which were not appropriately educated in the colleges of pharmacy. There are currently seven hospitals operating the program in Korea, and all of those are located in Metropolitan Seoul area. Most hospitals administer examination and interview to select competent pharmacists while some other hospitals select those based on paperwork and interview tests. Although the program contents are mostly similar, some variation were identified between the programs. Title conferred after accomplishment of the program has not been officially accredited by educational authority. In June of 2008, Korean Society of Health-System Pharmacists promulgated an internal regulation as an attempt to standardize the program contents and to encourage efficient management of the program. Since the regulation has now been effective, it is expected that the regulation may help clinical pharmacy education in Korea move toward advanced level.

Seed collection strategies for plant restoration with the aid of neutral genetic diversity

  • CHUNG, Mi Yoon;SON, Sungwon;MAO, Kangshan;LOPEZ-PUJOL, Jordi;CHUNG, Myong Gi
    • Korean Journal of Plant Taxonomy
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    • v.49 no.4
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    • pp.275-281
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    • 2019
  • One key step in the plant restoration process is the collection of seeds from the field. For the selection of source populations of target plant species for translocation purposes (reintroduction or reinforcements), several approaches are possible. A practical method involves the use of data from reciprocal transplant studies. If no direct data are available, knowledge of population genetics and the phylogeography of the target species can serve as an alternative. In this short review, we briefly propose guidelines for those collecting seeds for plant species restoration based on population genetics theory, focusing on two main questions: Where does the plant material come from and how are sources designated, and how are seeds efficiently collected from local populations? While genetic data on a larger scale (phylogeography and population genetics) are needed to form a reply to the first question, similar data on a smaller scale (fine-scale genetic structures within populations) are necessary to shed light on the second issue.

A Novel Stabilizing Control for Neural Nonlinear Systems with Time Delays by State and Dynamic Output Feedback

  • Liu, Mei-Qin;Wang, Hui-Fang
    • International Journal of Control, Automation, and Systems
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    • v.6 no.1
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    • pp.24-34
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    • 2008
  • A novel neural network model, termed the standard neural network model (SNNM), similar to the nominal model in linear robust control theory, is suggested to facilitate the synthesis of controllers for delayed (or non-delayed) nonlinear systems composed of neural networks. The model is composed of a linear dynamic system and a bounded static delayed (or non-delayed) nonlinear operator. Based on the global asymptotic stability analysis of SNNMs, Static state-feedback controller and dynamic output feedback controller are designed for the SNNMs to stabilize the closed-loop systems, respectively. The control design equations are shown to be a set of linear matrix inequalities (LMIs) which can be easily solved by various convex optimization algorithms to determine the control signals. Most neural-network-based nonlinear systems with time delays or without time delays can be transformed into the SNNMs for controller synthesis in a unified way. Two application examples are given where the SNNMs are employed to synthesize the feedback stabilizing controllers for an SISO nonlinear system modeled by the neural network, and for a chaotic neural network, respectively. Through these examples, it is demonstrated that the SNNM not only makes controller synthesis of neural-network-based systems much easier, but also provides a new approach to the synthesis of the controllers for the other type of nonlinear systems.

A Research on the Japanese Alternative Dispute Resolution Law (일본의 ADR법(法)에 관한 연구(硏究))

  • Kim, Sang-Chan
    • Journal of Arbitration Studies
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    • v.16 no.3
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    • pp.127-160
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    • 2006
  • Civil lawsuits have been the main instruments to resolve any civil disputes until recent times but it has its limitations in resolving all disputes in the specialized and technical disputes only according to the civil trial process. Therefore, many countries have carried out a series of discussions and investigations into the system of Alternate Dispute Resolution(ADR). It should especially be noted that all related countries in the world have enacted a basic ADR law to accelerate the usage of the ADR system. The most representative cases are the American Alternative Dispute Resolution Act of 1998 and Japan's Alternative Dispute Resolution Promotion Law set up in December 2004. As such, there is a need for Korea to enact a basic law regarding ADR following the world trend of major nations. This paper looks closely not only into the enactment circumstances and contents of Japan's ADR law whose legal system is similar to that of Korea but also the aftermath discussions of the Japanese academic circles into consideration, in the hopes of providing reference data for the legislation of the Korean ADR system and further aiding in the development of the ADR law theory.

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