• 제목/요약/키워드: Core collection

검색결과 328건 처리시간 0.034초

코어드릴링에 의한 중성화 신속평가 방법을 이용한 콘크리트 구조물의 중성화 현장 적용성 평가 (Field Application of Rapid Neutralization Assessment Method Using Core Drilling in Concrete Structures)

  • 임군수;이현직;백성진;이혁주;김종;한민철
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2023년도 가을학술발표대회논문집
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    • pp.15-16
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    • 2023
  • In this paper, we aimed to develop a new method for diagnosing the depth of neutralization in architectural and civil engineering structures using the core drilling method, which combines the speed of drilling with the accuracy of core ringing. When compared to the drilling method, the core drilling method showed a lower measurement deviation of 1-2mm (7.6%) in confirming the depth of neutralization. This is believed to be a result of potential interference during the sample collection process in the drilling method, where the drill may pass through aggregates, leading to overestimation, as indicated in previous studies. The rapid evaluation of neutralization using the core drilling method serves as an alternative to address the issues associated with both drilling and core ringing methods in diagnosing the depth of neutralization. It offers a solution to the inaccuracy caused by coarse aggregates and the cumbersome post-processing steps required for neutralization diagnosis. Our proposed technique aims to provide an accurate and expedited diagnosis of neutralization depth without the need for additional processes.

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장서평가에 관한 소고 -특히 이용조사를 중심으로- (Use Studies of Library Collections)

  • 유재옥
    • 한국문헌정보학회지
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    • 제15권
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    • pp.175-195
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    • 1988
  • Use studies of library collections have been conducted as a method of evaluating collections in a library. The main purpose of use studies is to evaluate the quality of a library collection in terms of extent and mode of its use. In addition to use studies, both quantitative and qualitative methods could be utilized in order to evaluate a library collection. However, the quantitative and qualitative collection evaluation methods are more concerned with the collection itself than with its use. Use studies have been conducted in large academic libraries for the following specific purposes: 1) They attempt to identify little used portion of collections that can be retired less accessible and less expensive storage area. 2) They try to identify core collections to satisfy some degree of circulation demands in the near future. 3) They try to identify use patterns of selected subject areas or type of books that can be used to adjusting collection development practices or fund allocations. 4) They try to assess the document delivery capability of a library to improve their availability. A number of methodologies employed for these specific purposes fall into four major categories; 1) circulation analysis method, 2) last circulation method, 3) relative use method, and 4) document delivery test. Each method is briefly reviewed with its limitations.

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Effect of Core Morphology on the Decomposition of CCI₄ over the Surface of Core/Shell Structured Fe₂O₃/MgO Composite Metal Oxides

  • 김해진;강진;박동곤;권호진;Kenneth J. Klabunde
    • Bulletin of the Korean Chemical Society
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    • 제18권8호
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    • pp.831-840
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    • 1997
  • Core/shell structured composite metal oxides of Fe2O3/MgO were prepared by thermal decomposition of Fe(acac)3 adsorbed on the surface of MgO cores. The morphology of the composites conformed to that of the MgO used as the cores. Broad powder X-ray diffraction peaks shifted toward larger d, large BET surface area (∼350 m2/g), and the size of crystalline domains in nano range (4 nm), all corroborate to the nanocrystallinity of the Fe2O3/MgO composite which was prepared by using nanocrystalline MgO as the core. By use of microcrystalline MgO as the core, microcrystalline Fe2O3/MgO composite was prepared, and it had small BET surface area of less than 35 m2/g. AFM measurements on nanocrystalline Fe2O3/MgO showed a collection of spherical aggregates (∼80 nm dia) with a very rough surface. On the contrary, microcrystalline Fe2O3/MgO was a collection of plate-like flat crystallites with a smooth surface. The nitrogen adsorption-desorption behavior indicated that microcrystalline Fe2O3/MgO was nonporous, whereas nanocrystalline Fe2O3/MgO was mesoporous. Bimodal distribution of the pore size became unimodal as the layer of Fe2O3 was applied to nanocrystalline MgO. The macropores in a wide distribution which the nanocrystalline MgO had were absent in the nanocrystalline Fe2O3/MgO. The decomposition of CCl4 was largily enhanced by the overlayer of Fe2O3 on nanocrystalline MgO making the reaction between nanocrystalline Fe2O3/MgO and CCl4 be nearly stoichiometric. The reaction products were environmentally benign MgCl2 and CO2. Such an enhancement was not attainable with the microcrystalline samples. Even for the nanocrystalline MgO, the enhancement was not attained, if not with the Fe2O3 layer. Without the layer of Fe2O3, it was observed that the nanocrystalline domain of the MgO transformed into microcrystalline one as the decomposition of CCl4 proceeded on its surface. It appeared that the layer of Fe2O3 on the particles of nanocrystalline Fe2O3/MgO blocked the transformation of the nanocrystalline domain into microcrystalline one. Therefore, in order to attain stoichiometric reaction between CCl4 and Fe2O3/MgO core/shell structured composite metal oxide, the morphology of the core MgO has to be nanocrystalline, and also the nanocrystalline domains has to be sustained until the core was exhausted into MgCl2.

Impact of Open Access Models on Citation Metrics

  • Razumova, Irina K.;Kuznetsov, Alexander
    • Journal of Information Science Theory and Practice
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    • 제7권2호
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    • pp.23-31
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    • 2019
  • We report results of selection-bias-free approaches to the analysis of the impact of open access (OA) models on citation metrics. We studied reference groups of Gold and Green OA articles and the group of non-OA (Paywall) articles with the new functionality of the Web of Science Core Collection database, the InCites platform of Clarivate Analytics, and the Dimensions database of Digital Science. For each reference group we obtained the values of the percent of cited articles and citation impact and their dependence on the depth of the citation period. Different research fields were analyzed in two schemas of the InCites platform. We report the higher values and growth rates of the citation metrics: citation impact and %Cited, in the OA reference groups over the Paywall group. The Green OA articles demonstrate the highest values of citation metrics among all the OA models. Dependence of the value of citation impact on citation period follows linear law with R2 values close to 0.9-1.0. The overall annual growth rates of citation impact of the Green OA, Gold OA, and the Paywall articles, k equal, respectively, 3.6, 2.4, and 1.4 in Dimensions and 4.6, 3.6, and 2.3 in the Web of Science Core Collection. We suppose that earlier results reported for the articles in pure OA journals vs. articles in Paywall journals were affected by the high citation impact of the Green and Hybrid OA articles that could not be elucidated in the Paywall journals at that time.

국가 지식정보의 효율적인 유통체제 구축을 위한 대학 리포지토리 평가 지표 개발: dCollection을 중심으로 (Developing an Evaluation Indicator of Institutional Repositories toward Efficient Distribution Infrastructure of National Knowledge focusing on the dCollection)

  • 김현희;곽병희;안태경;장우권;이수영
    • 한국도서관정보학회지
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    • 제36권3호
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    • pp.85-107
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    • 2005
  • 기관 리포지토리에 대한 평가지표를 개발하기 위하여 국내외 기관 리포지토리에 대한 문헌 연구를 통하여 평가요소를 도출하였으며, 도출된 평가 요소들이 도서관 업무 현장에서의 적용가능성과 타당성을 검증하기 위하여 국내외 16개 대학도서관을 대상으로 사례연구와 20개 대학도서관을 대상으로 델파이조사를 실시하였다. 연구결과, 4개 평가영역과 29개 평가지표를 도출하였다. 제안된 평가지표는 향후 dCollection 사업을 수행하는 대학도서관의 운영현황을 객관적으로 평가하여 바람직한 방향으로 운영을 개선할 수 있는 하나의 지침으로써 활용될 수 있을 것이다.

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핵심질의 클러스터와 단어 근접도를 이용한 문서 검색 정확률 향상 기법 (A Method for Precision Improvement Based on Core Query Clusters and Term Proximity)

  • 장계훈;이경순
    • 정보처리학회논문지B
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    • 제17B권5호
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    • pp.399-404
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    • 2010
  • 본 논문에서는 상위 검색결과 문서의 정확률을 향상시키기 위하여 핵심질의 클러스터와 단어 근접도를 이용해 재순위화하는 방법을 제안한 다. 언어모델에 의한 초기 검색결과를 상위 문서에 대해 발생한 질의어휘 조합을 기반으로 문서를 클러스터링한다. 질의어휘 조합 클러스터에 대해 질의어휘 사이의 근접도를 이용하여 핵심질의 클러스터를 선택한다. 질의의 문맥정보를 이용해 핵심질의 클러스터의 문서를 재순위화한다. 뉴스집합인 TREC AP 컬렉션에 대해 언어모델과 제안한 방법의 문서 정확률을 비교한 결과 제안방법이 언어모델에 비해 상위 100개 문서(P@100)에서 11.2% 성능이 향상되었다.

대학도서관에서의 고전자료 개발방안 -부산대학교 도서관을 중심으로- (The Development Program of the Collection for Korean Classical Materials in the University Library - With emphasis on the library of Pusan National University)

  • 송정숙
    • 한국문헌정보학회지
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    • 제25권
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    • pp.215-232
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    • 1993
  • The Long-Term Development Plan of the Pusan National University(PNU) has announced on 1991 in order to reach its roles and levels as an University with international standards, a Graduate School research-oriented and a core university in its community through accomplishment of this Plan. University libraries would be planned to support their universities' goals. Therefore the Library of PNU is facing on the task for supporting the Plan. The Collection for Korean Classical Materials (CKCM) is not limited in Korean Literature, Korean History, Korean Philosophy fields but covered the academic fields except a hightech science : Humanities, social science. pure science, applied science and arts etc. However, the Library of PNU does not have the organization, special librarian and budget for CKCM. Under this notion organization, budget and librarian for the collection would be followed. The CKCM contains the original editions, photography editions, copied issues. microform reproductions with comprehensive subjects in the fields of studies. Especially for the collection of treasure books the role of the Library of PNU induce to open individuals' collections or families' collections to public through the Library. The equipments for preserving rare books and treasure books are the conditioners for humidity and temperature, automatic extinguishment system. The reference materials, copy machine and reading room are requested for the user service of CKCM. The materials would be one of the most important thing in study and research. Therefore the Library of PNU need to pay attention to develop and preserve CKCM.

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반응표면법을 이용한 양측 철심형 영구자석 선형 동기기의 구조 최적화 (Structure Optimization of Double-Sided Iron-Core Type Permanent Magnet Linear Synchronous Machine Using Response Surface Method)

  • 이상건;주옥오;조윤현
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.1210-1211
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    • 2011
  • The inherent drawback of iron-core type permanent magnet linear synchronous motor (PMLSM) is detent force that is dependent on several major factors such as PM length, slot clearance, and skewing. To minimize the detent force, this paper proposes a structure optimization using the combination computation of two dimensional (2-D) finite element analysis (FEA) and response surface methodology (RSM). The RSM, that is a collection of the statistical and mathematical techniques, is utilized to predict the global optimal solution based on the FEA calculated results of the detect forces for different combinations of factors. With the help of the combination computation the high capacity iron-core type PMLSM with more than 12000 N propulsion forces only contains less than 3 N detent forces.

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