• Title/Summary/Keyword: closed range

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A study of descriptive forms of catalogue and searching method for dissertations (학위논문의 목록기술형식 및 검색방법 고찰)

  • 조호일
    • Journal of Korean Library and Information Science Society
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    • v.12
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    • pp.133-160
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    • 1985
  • In college or university libraries, the data of dissertations is one of the important academic information data. But traditional cataloging rules of dissertations and the method of operation is not only didn't unify but also fit to actual circumstances of library. This reason make librarians waste of time and the situation about piling up of unprocessed data don't make library services properly. In this papers, to analyze the above mentioned problems, I have investigated with questionaries about actual examples of construction methods of call number and item describing form of dissertations which is being used now in every college library in Korea. With the replied 61 questionaries which was compared with and investigated to merits and faults about library itself, I have showed revision ways. The characteristics of the revision ways are the followings. 1) Deleted informal and unmeaning descriptions and simplified describing. 2) Recommended to operating one or two kinds describing items which are only necessary. 3) Made call number specifically and then it make us easy to identify data and simultaneously call number can do its original action. 4) shelving range of data is made to colleges, years, departments, majors but in same departments, author's name is recommended by Korean alphabetical ordering. Besides, for proper and systematic management and operating of data. It must be necessary to recommend that reading systems of closed shelves type, incoming and outgoing and shelving by fulltime exclusive charged librarian, separate management of items and data are recommended.

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A Study on Characteristics of Coupled Line Employing Periodical Ground Structure on GaAs MMIC (GaAs MMIC상에서 주기적 접지구조를 가지는 결합선로의 절연특성에 관한 연구)

  • Kim, Se-Ho;Kang, Suk-Youb;Yun, Young
    • Journal of Advanced Marine Engineering and Technology
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    • v.33 no.1
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    • pp.159-165
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    • 2009
  • In this study, using a periodical ground structure(PGS) on GaAs monolithic microwave integrated circuit(MMIC), transmission line with a high isolation characteristic was developed for application to compact signal/bias lines of highly integrated MMIC. And the origin of the high isolation characteristic was theoretically investigated. The high isolation characteristic was originated from a resonance between adjacent microstrip lines employing PGS. With only a spacing of $20{\mu}m$, the coupled microstrip line employing PGS showed an isolation value of -47 dB at 60 GHz. The frequency range for high isolation was easily controlled by changing the PGS structure. Above results indicate that microstrip lines employing PGS are very useful for application to compact signal/bias lines of highly integrated MMIC requiring a high isolation characteristics between lines. In addition, equivalent circuit employing closed-form equation for the coupled line with PGS was also extracted.

Expected Neighbor's Relation according to Socially Integrative Planning Elements (사회통합적 계획 요소에 따른 예상 이웃관계에 관한 연구)

  • Lin, Eui-Sun;Lee, Yeun-Sook
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2009.11a
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    • pp.11-16
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    • 2009
  • Public rental apartment has suffered social exclusion problem, stemmed from its closed planing for a very specific range of the disadvantaged population. Thereby, it has been recognized as a disliked residential facility. To alleviate this problem, various approaches have been tried such as ownership-tenant mixture, and different unit size mixture. The purpose of this study is to grasp the expected social relation among neighboring residents according to socially integrative planing elements such as ownership, unit size and family life cycle match. Thirty eight graduate students in architecture and housing field responded to the questionnaire which was specifically made to identify relations of 28 neighboring situations based on $2{\times}2{\times}2$ variable composition. Frequency, percentage and MDS(multidimensional scaling) were used to analyze data. As a result, the order of preferred matchy were identified. The match between rental/small/children group and ownership/middle/children group was turned out to be the most desirable while the match between rental/small/children family group and rental/small/elderly group was found the least desirable. Spatial representations of the relationships among 8 household types were delineated. In conclusion, the definite patterns of the favorable and unfavorable match were found. This result is expected to be used as a reference in developing a strategic match to promote the rental apartments social integration in Korea.

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An Anti-Windup Compensation for Systems with Saturation Actuators (포화 요소가 있는 계를 위한 와인드업 방지 보상 방법)

  • 장원욱;박영진
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.7
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    • pp.1332-1340
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    • 1992
  • A novel approach based on a nonlinear compensator is prposed to prevent 'windup', which is caused by the saturation of the acutator and the integral action of the controller. The anti-windup compensator is located between the conventional linear controller, designed neglecting the saturation, and the actuator. It was proven based on the describing function method that, if the closed loop control systems are stable assuming no saturation, then there may exist a range of compensator gain which prevents any limit-cycle. The computer simulation results show that the compensator proposed in the manuscript can eliminate the limit cycle and improve the transient response.

Inductive Micro Displacement Detecting System with High Sensitivity and Low Linearity Error

  • Park, Dong-June;Park, In-Mook;Kim, Soo-Hyun
    • International Journal of Precision Engineering and Manufacturing
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    • v.2 no.3
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    • pp.54-60
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    • 2001
  • A newly designed inductive micro displacement detecting system is presented. The proposed inductive system consists of driving coils, position-detecting coils, cores, and closed-loop formed magnetic blocks. The cores and magnetic blocks are made of Mn-Zn ferrite. When AC sine wave is applied to the driving coils, the time derivative flux is generated within the system, and then induced voltages arise in the position-detecting coils according to the core\`s position. Putting the cores to be moved proportionally to the input displacement, the induced voltage is proportional to input displacement. The parameters that affect the system characteristics are turn ratio, air-gap size, excitation frequency, overlap area, load resistance, capacitance effect, and so forth. Based on the experimental results, the system parameters are selected in such a way as to have high sensitivity ad stable responses. The sensitivity of the proposed inductive displacement-detecting system is greater than 2800mV.V-1mm-1 and the linearity error is below $\pm$0.10% in the range of $\pm$200㎛.

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Surgical Treatment of Atrial Septal Defect: Secundum Type (심방중격결손증의 외과적 요법)

  • 안광필;이영균
    • Journal of Chest Surgery
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    • v.8 no.2
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    • pp.81-88
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    • 1975
  • Up to October 31, 1975, 34 cases of atrial septal defect, secundum type, operated in this department, were presented. This is 23.2% of all congenital heart diseases, operated utilizing cardiopulmonary bypass, in this department during this period [34 out of 146]. Out of 34 cases, 32 cases are pure ostium secundum type and one case is sinus venosus and another one is ostium secundum type with partial anomalous pulmonary venous drainage. Six cases of endocardial cushion defect and 3 cases of trilogy of Fallot are excluded in this report. All 34 cases are repaired under direct vision utilizing extracorporeal circulation. Among 34 cases of atrial septal defect, 16 cases are male, and 18 cases are female. Their ages range between 3 to 48 years, but over 59% of the cases are below the ages of 20 years. Thirty-two cases are repaired by direct sutures while 2 cases are repaired with Teflon patches. The average perfusion time is 30 minutes; the shortest 12 and the longest 81 minutes. The number of the defect is single in 31 cases, double in 2 cases, triple in one case. But the associated defect except the main defect are so small as can be closed by simple direct suture. The size of the defect is average $12cm^2$; the smallest 0.7 and the largest $25cm^2$. The surgical mortality is 2 cases [5.6%] and other cases are found to be excellent in the follow up studies.

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Design of pole-assignment self-tuning controller for steam generator water level in nuclear power plants (원전 증기 발생기 수위 제어를 위한 자기 동조 제어기 설계)

  • Choi, Byung-Jae;No, Hee-Cheon;Kim, Byung-Kook
    • Journal of Institute of Control, Robotics and Systems
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    • v.2 no.4
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    • pp.306-311
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    • 1996
  • This paper discusses the maintenance of the water level of steam generators at its programmed value. The process, the water level of a steam generator, has the nonminimum phase property. So, it causes a reverse dynamics called a swell and shrink phenomenon. This phenomenon is severe in a low power condition below 15 %, in turn makes the start-up of the power plant too difficult. The control algorithm used here incorporates a pole-assignment scheme into the minimum variance strategy and we use a parallel adaptation algorithm for the parameter estimation, which is robust to noises. As a result, the total control system can keep the water level constant during full power by locating closed-loop poles appropriately, although the process has the characteristics of high complexity and nonlinearity. Also, the extra perturbation signals are added to the input signal such that the control system guarantee persistently exciting. In order to confirm the control performance of a proposed pole-assignment self-tuning controller we perform a computer simulation in full power range.

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A Study on Characteristics of Digital Learning Contents Space and Suggestion on Design Directions (디지털 학습콘텐츠 공간특성 분석과 디자인 방향 제시)

  • Kim, Mi-Shil;Moon, Jeong-Min
    • Korean Institute of Interior Design Journal
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    • v.19 no.6
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    • pp.11-19
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    • 2010
  • Technological development of information and communication have brought sharp changes to every sector such as society, culture, economy and education because of knowledge and information-oriented society. The number of classes has decreased, and some schools are closed or incorporated due to decrease of the population. Such phenomenon has brought changes to learning using digital technology and space. A change called digital innovation is characterized by interactive communication centering on the internet network. Therefore, it is very important to predict educational environment to be changed according to digital environment and to note how real learning space is changed. The development of digital technology in society in general presents two concepts of digital and contents, digitalized information. Such technology is recognized as a new paradigm in education sector and a new space is created through participation of instructors and learners in learning space. This study analysed cases of learning space of elementary schools based on bibliographical examination and related bibliography including data from academic presentations and news release to present developed leaning space. To present healthy and creative learning environment which can lead knowledge and information-based society in the future, the preface described the background, purpose, methods and range of the study, and analysed transitional processes of society and culture, digital learning contents, and learning space in education of elementary schools. Finally the study identified trends and cases of research on learning space and suggested digital learning contents space.

The Geographical Language and Location Characteristics of Rural Settlements focused on Miwon Myeon in the Integrated Cheongju City (농촌자연마을의 지명어와 입지특성에 관한 연구 -통합청주시 미원면을 중심으로-)

  • Kim, Tai-Young
    • Journal of the Korean Institute of Rural Architecture
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    • v.17 no.4
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    • pp.25-32
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    • 2015
  • This paper is to research the geographical language and location characteristics of 126 rural settlements focused on Miwon Myeon in the Integrated Cheongju City. The main results are as follows : Firstly, the geographical languages of 126 settlements are classified and categorized in the order of nature (91units, 72.22%), manmade and location related(35 Units, 27.78%). The geographical languages of nature, quite much in comparison with the others, are also classified into 39 'mountain', 46 'valley', and 6 'stream' units in location characteristics. Secondly, the geographical languages of nature have 46 'valley' units, much in comparison with the others. The open circular valleys are extended from Miwon Ri of town center to Gubang Ri along route 19. The closed valleys are placed in the west and north band of town center with a background of mountain range. The 46 'valley' units are distributed widely throughout these places. Thirdly, The geographical languages of 39 'valley' units except original 7 'valley' units are categorized with the secondary 'mountain'(rock and topography related), 'stream', 'manmade', and 'location related'. And so in considering the location characteristics of rural settlements, we will have to grasp the another meaning of the geographical language.

Numerical Solution of Steady Flow and Heat Transfer around a Rotating Circular Cylinder (가열된 회전원주를 지나는 정상유동 및 열전달해석)

  • 부정숙;이종춘
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.12
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    • pp.3135-3147
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    • 1993
  • A numerical method is presented which can solve the steady flow and heat transfer from a rotating and heated circular cylinder in a uniform flow for a range of Reynolds number form 5 to 100. The steady response of the flow and heat transfer is simulated for various spin parameter. The effects on the flow field and heat transfer characteristics known as lift, drag and heat transfer coefficient are analyzed and the streamlines, velocity vectors, vorticity, temperature distributions around it were scrutinized numerically. As spin parameter increases the region of separation vortex becomes smaller than upper one and the lower region will vanish. The lift force, a large part is due to the pressure force, increases as the Reynolds number and it increases linearly as spin parameter increases. The pressure coefficient changes rapidly with spin parameter on the lower surface of the cylinder and the vorticity is sensitive to the spin parameter near separation region. As spin parameter increases the maximum heat coefficient and the thin thermal layer on front region are moved to direction of rotation. However, with balance between the local increase and decrease, the overal heat transfer coefficient is almost unaffected by rotation.