• 한국도서관정보학회지
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• 제41권2호
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• pp.81-106
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• 2010

이 연구는 초 중 고등학생들을 대상으로 하는 자기주도적 탐구학습 프로그램의 교육적 효과를 평가하고 개선 방안을 탐색하기 위한 것이다. 설문조사와 질적 자료를 통해 대구광역시교육청에서 2009년에 시행한 '책쓰기' 교육 활동에 대한 교사와 학생들의 만족도를 조사하였고 그와 관련된 제반 요인에 대해 검토하였다. 학생 스스로 주제를 선정하여 자료를 찾고, 다양한 자료를 활용하여 보고서로 만들고 책을 출판하는 '책쓰기' 프로그램에 대해 교사와 학생들은 어렵고 생소한 경험이었지만 성취감과 자기주도적 탐구학습의 가치를 발견한 것으로 드러났으며, 프로그램의 개선을 위한 몇 가지 과제가 부각되었다

• 한국통신학회논문지
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• 제31권11C호
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• pp.1052-1057
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• 2006

본 논문에서는 고밀도 광기록 장치에서 발생하는 디스크 기울임 현상으로 인한 검출 성능 저하를 방지하기 위해서 디스크 기울임 분석기를 갖는 적응 등화 PRML 검출 방법을 VerilogHDL을 이용하여 구현하였다. 디스크 기울임의 분석을 위하여 고정된 패턴으로 일정한 간격마다 반복되는 동기 데이터를 이용하여 분석된 디스크의 기울임 정도를 측정하여 ROM에 저장된 등화기 계수값과 가지 메트릭의 기준값을 갱신한다. 이러한 방법은 지속적으로 계수값을 계산하여 갱신시켜줘야 하는 기존의 적응등화 방법에 비해 간단하게 각각의 계수값을 갱신시킬 수 있다. Hynix $0.35{\mu}m$ STD cell library로 회로를 합성한 결과 35K 정도의 게이트를 필요로 하고 최대동작속도 140MHz의 성능을 보였다.

• 한국문헌정보학회지
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• 제41권4호
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• pp.387-412
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• 2007

광범위한 분야에 걸쳐 다양한 형태의 대상자원을 지닌 전통예술분야의 아카이빙을 위한 보존 메타데이터 스키마를 설계하였다. 이를 위해 OAIS참조모델과 PREMIS 데이터 사전 그리고 다양하게 개발된 보존 메타데이터 규격들을 참조하고 한국전통예술자료의 특성을 조사하고 분석하여 기존 규격과의 호환성을 유지하는 것을 대원칙으로 하고 전통예술자료 도메인에 대한 특징적 정보를 기술하여 보존과 활용에 필요한 최적의 보존메타데이터 스키마를 설계하려 노력하였다. 모든 메타데이터 요소에 어떤 네임스페이스에서 온 것인지를 선언하여 지속적인 관리를 꾀했으며 참조한 모델의 원래 규격을 최대한 준용하였고. 국악원의 자료의 특성과 새로운 서비스의 제공에 필요한 요소를 새로 생성하여 기존 스키마를 확장하고 수정하여 전통예술자료의 아카이빙을 위한 최적의 메타데이터 스키마를 제안하게 되었다.

• 한국문헌정보학회지
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• 제50권2호
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• pp.147-181
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• 2016

이 연구는 장애인 본인 및 가족, 관련자 등 장애 관련 다양한 이용자들이 실질적으로 필요로 하는 장애관련 정보를 파악과 함께 정보유형에 따른 이용자들의 인식을 비교분석하여 체계적이고 효과적인 이용자 맞춤형 정보제공을 위한 기초자료를 마련하는데 있다. 이를 위해 문헌조사와 장애인, 장애인보호자, 장애기관 종사자, 장애인 연구자 등을 대상으로 설문조사를 병행하였다. 분석결과, 장애인 및 장애 관련자들의 주요정보원은 일반포털 사이트이며, 중요 정보유형은 구인구직정보, 이동편의(교통)정보, 의료기관 정보 등이다. 또한 장애인이 비장애인에 비해 정보의 중요성이 낮고 자료의 획득도 어렵게 느끼고 있었으며, 장애유형에 따라서 중요 정보유형 및 획득의 용이성이 차이가 나타났다.

• Mass Spectrometry Letters
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• 제10권3호
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• pp.93-101
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• 2019

Algorithms and software for predicting tandem mass spectra have been developed in recent years. In this work, we explore how distinct in silico $MS^2$ spectra are predicted for isomers, i.e. compounds having the same formula and similar molecular structures, to differentiate between them. We used the CFM-ID 2.0/3.0 predictor with regard to (a) test compounds, whose experimental mass spectra had been randomly sampled from the MassBank of North America (MoNA) collection, and to (b) the most widespread isomers of test compounds searched in the PubChem database. In the first validation test, in silico mass spectra constitute a reference library, and library searches are performed for test experimental spectra of "unknowns". The searches led to the true positive rate (TPR) of ($46-48{\pm}10$)%. In the second test, in silico and experimental spectra were interchanged and this resulted in a TPR of ($58{\pm}10$)%. There were no significant differences between results obtained with different metrics of spectral similarity and predictor versions. In a comparison of test compounds vs. their isomers, a statistically significant correlation between mass spectral data and structural features was observed. The TPR values obtained should be regarded as reasonable results for predicting tandem mass spectra of related chemical structures.

• Nuclear Engineering and Technology
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• 제53권10호
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• pp.3151-3157
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• 2021

Copper is an important structural material in various nuclear energy applications, therefore the correct knowledge of copper cross sections is crucial. The presented paper deals with a validation of different copper transport libraries by means of activation of selected samples. An intense ²⁵²Cf(sf) source with a reference neutron spectrum was used as a neutron source. After irradiation, the samples were measured using a high purity germanium detector and the dosimeter reaction rates were inferred. These experimental data were compared with MCNP6 calculations using CENDL-3.1, JENDL-4.0, ENDF/B-VII.1, ENDF/B-VIII.0, JEFF-3.2 and JEFF-3.3 evaluated Cu transport libraries. The experiment specifically focuses on ⁵⁸Ni(n,p)⁵⁸Co, ⁹³Nb(n,2n)^92mNb, ¹⁹⁷Au(n,g)¹⁹⁸Au and ⁵⁵Mn(n,g)⁵⁶Mn dosimetry reactions. Evaluated activation cross sections of these dosimetric reactions were taken from the IRDFF-II library. The best library performance depends on the energy region of interest.

• Nuclear Engineering and Technology
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• 제53권8호
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• pp.2454-2463
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• 2021

The objective of this research is to the use of americium (AmO₂) as a burnable absorber effectively instead of conventional gadolinium (Gd₂O₃) for VVER-1200 reactor by analyzing its impacts on reactivity, power peaking factor (PPF), safety factor, and quality of the spent fuel. The assembly is burned to 60 GWd/t by using SRAC-2006 code and JENDL-4.0 data library for finding the optimum amount and effective way of using AmO₂ as a burnable absorber. From these studies, it is found that AmO₂ can decrease the excess reactivity like Gd₂O₃ without changing the criticality life span and enrichment of ²³⁵U. A homogeneous mixture of the 0.20% AmO₂+ 4.95% enriched UO₂ fuel rod (model MF-4) decreases the PPF than the reference assembly. The use of AmO₂+UO₂ in the integral burnable absorber (IBA) rod or the outer layer could also decrease the PPF up to 10 GWd/t but increases rapidly after 30 GWd/t, which could be a safety threat. The fuel temperature coefficient and void coefficient of the model MF-4 are the same as the reference assembly. In addition, 22% of initially loaded Am are burning effectively and contributing to the power production.

• Nuclear Engineering and Technology
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• 제51권7호
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• pp.1729-1737
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• 2019

This paper presents neutronics design of VVER-1000 fuel assembly using burnable poison particles (BPPs) for controlling excess reactivity and pin-wise power distribution. The advantage of using BPPs is that the thermal conductivity of BPP-dispersed fuel pin could be improved. Numerical calculations have been conducted for optimizing the BPP parameters using the MVP code and the JENDL-3.3 data library. The results show that by using $Gd_2O_3$ particles with the diameter of $60{\mu}m$ and the packing fraction of 5%, the burnup reactivity curve and pin-wise power distribution are obtained approximately that of the reference design. To minimize power peaking factor (PPF), total BP amount has been distributed in a larger number of fuel rods. Optimization has been conducted for the number of BPP-dispersed rods, their distribution, BPP diameter and packing fraction. Two models of assembly consisting of 18 BPP-dispersed rods have been selected. The diameter of $300{\mu}m$ and the packing fraction of 3.33% were determined so that the burnup reactivity curve is approximate that of the reference one, while the PPF can be decreased from 1.167 to 1.105 and 1.113, respectively. Application of BPPs for compensating the reduction of soluble boron content to 50% and 0% is also investigated.

• 한국도서관정보학회지
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• 제9권
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• pp.241-266
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• 1982

This paper gives a summary and overview of a survey conducted at the catalogues of five universities in Daegu during November 1982. The major objective of this study was to secure information about user needs in order to improve the catalogue in Korean university libraries. Data was collected by a combined method of questionnaire and interview. A total of 379 respondents were taken on a randomly selected sample of catalogue users. Results of the survey can be summarized as follows: 1. Eighty-eight percent of the students answered that they had used the library more than twice a month. Nevertheless the number of students consulting the catalogue with the same frequency was only 220, or a n.0, pproximately 58 percent. Those who used the library most tended to use the catalogue more than those who rarely came to the library. 2. Those who had been shown how to use their own catalogue were only 32.5percent of which the students found the instruction sufficient for them to be able to use the catalogue were only 37.5 percent. In particular, they stated that instructions by printed materials and/or library orientation were so poor that they didn't give much help in using the catalogue. This problem makes many libraries to review their own method of instruction in order to encourage patrons to use the catalogue more effectively. 3. Most of the students consulted the catalogue in order to locate library materials. Known-item searches and subject searches were 84 and 16 percent respectively. While 70.5 percent of the students used the author-title catalogue without any difficulties, only 35.5 percent of those stated that using the classed catalogue was easy. 4. It was surprising that the number of students using title access in the search was far greater than that of students using author access. In contrast with this, other studies conducted by many earlier overseas investigators revealed that the great majority of patrons tended to use the latter first. Therefore, we should put more emphasis on the title entries in the catalogue itself as well as cataloging rules. 5. Most useful bibliographic elements in the entry were author, title, call number, date and publisher whereas edition, series statement and the location of publisher were rarely used compared with the other elements. Content note was the most desirable element in the entry to be involved, for many catalogers were used not to describe it on the note area. 6. The chief reason given for not using the catalogue was "I can manage without it" with "It's difficult to understand contents of the card entry." The other one was "It's useless to search materials by the catalogue because I've failed so many times to obtain them out of the stock." In response to this, circulation and acquisition system should be improved not to make such complaints any more.

• Journal of Communications and Networks
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• 제15권2호
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• pp.228-239
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• 2013

Peer-to-peer (P2P) systems have proved the most effective and popular file sharing applications in recent years. Previous studies mainly focused on equal service and differentiated service strategies when peers have no initial data before their downloads. For an upload-constrained P2P file sharing system, we model both the equal service process and the differentiated service process when the initial data distribution of peers satisfies some special conditions. Moreover, we show how to minimize the time required to distribute the file to any number of peers. The proposed fluid-based models can reveal the intrinsic relations among the initial data amount, the peer set size, and the minimum last finish time. The closed-form expressions derived from the extended models can closely approximate chunk-based models and systems, especially for relatively large files. As an application of the extended models, we show how to provide differentiated service efficiently to multiple peer sets. Since no limits are imposed on the upload bandwidth of peers or the size of each peer set, we believe that our analytic process and the results achieved can provide not only fundamental insights into bandwidth allocation and data scheduling but also a helpful reference for both improving system performance and building an effective incentive mechanism for P2P file sharing systems.