• Title/Summary/Keyword: collection.

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A Study on the Discharge Characteristics and the Collection Efficiency of the Electrostatic Precipitator for Pulverized Coal Boiler (미분탄 연소 보일러용 전기집진기의 방전특성 및 집진특성에 관한 연구)

  • Lee, Tae-Sik;Son, Jin-Woon;Nam, Chang-Woo;Lee, Kyu-Chul
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.49 no.10
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    • pp.570-576
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    • 2000
  • The discharge and the collection efficiency characteristics of an electrostatic precipitator have been studied under various operating conditions. The specific resistivity of pulverized coal dust was about 1013∼1014[${\Omega}{\cdot}cm$] and reached the maximum value of 6${\times}$1013[${\Omega}{\cdot}cm$] at 150[$^{\circ}C$]. Back corona has been occurred as dust contents and gas temperature increase. In the case of back corona occurrence, collection effciency decreased rapidly. This problem has been solved by increasing moisture contents. Experimental results showed that collection efficiency of the full wave voltage was higher than that of the pulse wave voltage. The modification parameter k of the collection efficiency equation was about 0.42.

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Building a text collection for Urdu information retrieval

  • Rasheed, Imran;Banka, Haider;Khan, Hamaid M.
    • ETRI Journal
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    • v.43 no.5
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    • pp.856-868
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    • 2021
  • Urdu is a widely spoken language in the Indian subcontinent with over 300 million speakers worldwide. However, linguistic advancements in Urdu are rare compared to those in other European and Asian languages. Therefore, by following Text Retrieval Conference standards, we attempted to construct an extensive text collection of 85 304 documents from diverse categories covering over 52 topics with relevance judgment sets at 100 pool depth. We also present several applications to demonstrate the effectiveness of our collection. Although this collection is primarily intended for text retrieval, it can also be used for named entity recognition, text summarization, and other linguistic applications with suitable modifications. Ours is the most extensive existing collection for the Urdu language, and it will be freely available for future research and academic education.

Development of Unmanned Vehicles System for Waste Collection Considering Worker Safety (작업자 안전을 고려한 무인 폐기물 수거차 시스템 개발)

  • Jung, Mingwon;Kim, Sangho;Lee, Sangmoo;Won, Daehee;So, Byungrok;Lee, Sangjun
    • The Journal of Korea Robotics Society
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    • v.17 no.4
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    • pp.477-483
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    • 2022
  • In this paper, we propose waste collection vehicle system with a safety device for worker safety and an autonomous driving function. The steering system is applied as MDPS (Motor Drive Power Steering) system to control the waste collection vehicle of the internal combustion engine. Safety-related errors is prevented through redundancy brake of the integrated system and the control braking system. In order to ensure safety between workers and waste collection vehicles, work guidelines and safety devices for emergency stop in case of danger are applied to vehicles. In addition, this research is conducted on improving the working efficiency through vehicle condition monitoring system and a short-range control system for field test. This research is aimed to secure stability through demonstration and contribute to the industrialization of unmanned waste collection vehicles.

ANALYSIS OF CHARGE COLLECTION EFFICIENCY FOR A PLANAR CdZnTe DETECTOR

  • Kim, Kyung-O;Kim, Jong-Kyung;Ha, Jang-Ho;Kim, Soon-Young
    • Nuclear Engineering and Technology
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    • v.41 no.5
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    • pp.723-728
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    • 2009
  • The response property of the CZT detector ($5{\times}5{\times}5\;mm^3$), widely used in photon spectroscopy, was evaluated by considering the charge collection efficiency, which depends on the interaction position of incident radiation, A quantitative analysis of the energy spectra obtained from the CZT detector was also performed to investigate the tail effect at the low energy side of the full energy peak. The collection efficiency of electrons and holes to the two electrodes (i.e., cathode and anode) was calculated from the Hecht equation, and radiation transport analysis was performed by two Monte Carlo codes, Geant4 and MCNPX. The radiation source was assumed to be 59.5 keV gamma rays emitted from a $^{241}Am$ source into the cathode surface of this detector, and the detector was assumed to be biased to 500 V between the two electrodes. Through the comparison of the results between the Geant4 calculation considering the charge collection efficiency and the ideal case from MCNPX, an pronounced difference of 4 keV was found in the full energy peak position. The tail effect at the low energy side of the full energy peak was confirmed to be caused by the collection efficiency of electrons and holes. In more detail, it was shown that the tail height caused by the charge collection efficiency went up to 1000 times the pulse height in the same energy bin at the calculation without considering the charge collection efficiency. It is, therefore, apparent that research considering the charge collection efficiency is necessary in order to properly analyze the characteristics of CZT detectors.

A Study on the Formulation of the Collection Development Policy for a National Library (국가도서관 장서개발정책 수립에 관한 연구)

  • Yoon, H.Y.;Chang, D.H.
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.21 no.4
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    • pp.107-122
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    • 2010
  • A national library bears responsibility to collect, develop, manage and preserve the national knowledge resources and heritages. The institution, in order to accomplish this duty, should center on systematically developed collection development policy. This paper, in this regard, strives to propose a model to comprise of basic principles of collection development of a national library in order for the effective management of resources by the types and subjects. Major emphasis was put on the nature of a national library as a legal deposit library, an information gateway, and a repository for national information resources. As a result, a model collection development policy appropriate for a national library has been proposed by analyzing cases in other countries to guide establishing principles for determining and analyzing the types and magnitude of the collection acquisition; by applying the Five-level conspectus to be optimal to collection magnitude; and, by identifying the essential elements in systematic development of national knowledge/information resources.

A Study on Separated Collection and Recycling in Apartment Housing Areas in Taegu Metropolitan City (대구시 아파트지역의 분리수거 및 재활용에 관한 연구)

  • 우형택;곽형숙
    • Journal of Environmental Science International
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    • v.4 no.3
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    • pp.153-167
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    • 1995
  • Recycling is receiving increasing social attention today as our nation begins to grapple with the significant problems caused by huge amount of municipal solid waste. The topic of recycling is not simple but extremely complicated. This study attempts to provide basic data and policy options for expanding and improving separated collection and recycling in public residential areas, through three case study of apartment housing areas in Taegu Metropolitan City. The main results of this study are summarized as follows. For the significant period of time, all three case areas had in common the extreme difficulty in establishing and operating the system of connecting public participation, collection and storage, transportation, and actual recycling of materials because of a variety of problems involved in this process. Both amounts of and prices for collected materials fluctuated considerably over time mainly due to monthly changes in recyclable home materials and the dynamic nature of recycling markets. Public questionnaire survey revealed the very high level of participation in separated collection, not only because almost all respondents well understood the necessity and importance of recycling, but because they also knew how to do separated collection. But overall activities were rated low and most respondents suggested the enlargement of public participation, the improvement of collection and storage facilities, and collection transportation networks. In particular, most respondents had little experience of using recycled Products and used mainly reproduced soap and bathroom tissue. Furthermore, they were considerably unsatisfied with low variety and quality of recycled products, their high prices and low availability in the market. Finally potential policy options and activities for improving separated collection and recycling are suggested.

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A Descriptive Study on the Collection Development Processes in Small Libraries (작은도서관 장서개발 과정에 관한 현상적 연구)

  • Chang, D.H.
    • Journal of Korean Library and Information Science Society
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    • v.42 no.4
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    • pp.203-221
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    • 2011
  • This study attempts to investigate the current stage of collection development process in small libraries through case study to eleven small libraries in Yeongnam region. Library collection is the primary element of a library and collection development is the starting point of librarians' duty. The researcher recognized the problems observed in collection development process in the case small libraries and discovered the widespread obstacles restraining the future development. Through the visits and observations, aging book collections, lack of diversity in the form of materials acquired, imbalance in subject distribution, and the imbalance in circulation are identified. Suggestions are to be added: collection development duty can not be fulfilled without proper support by local governments. While small libraries penetrate into peoples' territory, Public libraries should seek to enhance and improve their service orientation as well as a cooperative network with these small libraries.

Java Garbage Collection for a Small Interactive System (소규모 대화형 시스템을 위한 자바 가비지 콜렉션)

  • 권혜은;김상훈
    • Journal of KIISE:Software and Applications
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    • v.29 no.12
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    • pp.957-965
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    • 2002
  • Garbage collection in the CLDC typically employs a stop-the-world GC algorithm which is performing a complete garbage collection when needed. This technique is unsuitable for the interactive Java embedded system because this can lead to long and unpredictable delays. In this paper, We present a garbage collection algorithm which reduces the average delay time and supports the interactive environment. Our garbage collector is composed of the allocator and the collector. The allocator determines the allocation position of free-list according to object size, and the collector uses an incremental mark-sweep algorithm. The garbage collector is called periodically by the thread scheduling policy and the allocator allocates the objects of marked state during collection cycle. Also, we introduce a color toggle mechanism that changes the meaning of the bit patterns at the end of the collection cycle. We compared the performance of our implementation with stop-the-world mark-sweep GC. The experimental results show that our algorithm reduces the average delay time and that it provides uniformly low response times.

A Study on a Model Collection Development Policy for Children and Young Adults Libraries - with a special reference to the National Library for Children and Young Adults, Korea - (어린이청소년도서관 장서개발정책 모형 연구 - 국립어린이청소년도서관을 중심으로 -)

  • Chang, Durk-Hyun;Lee, Yeon-Ok;Yoon, Hee-Yoon
    • Journal of Korean Library and Information Science Society
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    • v.45 no.2
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    • pp.179-203
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    • 2014
  • The main objective of this study is to set a Collection Development Policy(CDP) for the National Library for Children and Young Adults(NLCY). Every library, in order to accomplish its duty, should maintain a written collection development policy. This paper, in this regard, strives to propose a model to comprise of basic principles of collection development of NLCY for the effective management of resources by the types and subjects. Major emphasis was put on the nature of the library as a repository and a service point for children and young adults, and a hub for children-related research. As a result, a model collection development policy appropriate for NLCY has been proposed by analyzing cases in other countries to guide establishing principles for determining and analyzing the types and magnitude of the collection acquisition.

A Study on the Model of Collection-Level Description based on Ontology for Resources Sharing (자원공유를 위한 온톨로지기반 컬렉션 단위 기술 모형개발 연구)

  • Lee, Hye-Won
    • Journal of the Korean Society for information Management
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    • v.25 no.3
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    • pp.209-230
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    • 2008
  • This study is based on the practical use for distributed resources considering growing network rapidly. The focal point of this study will be argued on semantic interoperability for sharing of resources, not be emphasized the technical issues of network. The aim of this article is developing the model of Collection-Level Description(CLD) for sharing of resources. The present article consists of a definition of collection in relation to the scope, objectives, and agents of the collection and an analysis of researches about CLD strengths and standards. Lastly, it was intended to construct the model focused on relation which was needed to be strengthened the existing CLD's function, thus, this study attempted to use the concept of ontology. The model of CLD based on ontology suggested the description could represent new relations inferred between classes and properties. Distinguishing class and property, furthermore, this study suggested properties were separated the characteristic of class and the relation with classes.