• 한국과학교육학회지
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• 제27권6호
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• pp.510-518
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• 2007

In many countries, secondary school science is no longer solely for those destined for careers in science, medicine or engineering and both boys and girls study biology, chemistry and physics. In Japan, secondary science has been studied by boys and girls as a compulsory subject since the establishment of the modem school system in the late 19th Century. However, although 'science for all' is becoming the norm, it appears that science is less popular with girls than it is with boys, and that lower-attaining students are not adequately catered for in Japan and elsewhere. In this paper, the author investigates gender issues in the secondary science curriculum and examines the curriculum for future scientists using a historical perspective and focusing on the case of Japan. An analysis of two historical issues, gender and the curriculum for future scientists, found that, firstly, the science curriculum needs to contain a clear statement of its aims, and, secondly, that the secondary science teacher is one of the most important factors influencing science teaching particularly for girls. ost important factors influencing science teaching especially for girls.

• 한국환경교육학회지:환경교육
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• 제21권3호
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• pp.26-40
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• 2008

This study aims to analyze the science content in secondary school environmental education(EE) textbooks and the environment-related content in secondary school science text- books. Firstly, a total of 73 EE and science textbooks for secondary students were reviewed, which three kinds of textbooks, secondary school EE textbooks and the 10th grade "Science" textbooks, were finally selected for analysis. Three researchers separately analyzed the textbooks using NAAEE framework(1996) for the development of EE materials. In condition that there was a disagreement in their opinion, they had discussed until they came to an agreement. The results showed that secondary school EE textbooks contained more and deeper science concepts than the 10th grade "Science" textbooks, which were evaluated better in all perspectives of the analysis framework. The 10th grade "Science" textbooks had more various teaching and learning activities than EE textbooks. It it expected that the new EE textbook developers should consider the ultimate goal of EE which focused the affective perspectives rather than the cognitive perspectives.

• 한국과학교육학회지
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• 제8권2호
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• pp.1-16
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• 1988

Secondary schools in Korea have been faced with several critical problems in their science education. Among them the most fundamental are the problems which involve the development and operation of science curricula. This study had, therefore, its objective to develop the suggestions for sabstantial science curricula of secondary schools. Actually the objectives are trifold as following specific description. ${\circ}$Analysis of the rationale and theory of science curricula. ${\circ}$Status survey of secondary science curricula and identification of the problems in development and operation of the curriculum in foreign and Korean secondary schools. ${\circ}$Development of suggestions for substantial science curriculam of secondary school. In order to attain these objectives the methods of literauare survey. questionaire and interview were used. Through these methods several problems are found and identified. The major findings and problems identified in this study are: ${\circ}$aims, goals, and objectives of science education are not dfferentiated. ${\circ}$the curricula show discipline-centered seleetion and organization of the content:neglect the relationship of science-technology-society and life-world context. ${\circ}$shortage of weekly instructional hours for science subjects. Other findings and problems are described and the descriptions of the suggestions for substantial curricula are followed at the end of this paper.

• International Journal of Computer Science & Network Security
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• 제21권5호
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• pp.168-174
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• 2021

The Cognitive radio (CR) is evolving technology for managing the spectrum bandwidth in wireless network. The security plays a vital role in wireless network where the secondary users are trying to access the primary user's bandwidth. During the allocation the any malicious user either he pretends to be primary user or secondary user to access the vital information's such as credentials, hacking the key, network jam, user overlapping etc. This research paper discusses on various types of attack and to prevent the attack in cognitive radio network. In this research, secondary users are identified by the primary user to access the primary network by the secondary users. The secondary users are given authorization to access the primary network. If any secondary user fails to provide the authorization, then that user will be treated as the malicious user. In this paper two approaches are suggested one by applying elliptic curve cryptography and the other method by using priority-based service access.

• 한국문헌정보학회지
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• 제33권1호
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• pp.145-160
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• 1999

학술정보는 1차자료와 2차자료의 2가지로 구분할 수 있다. 1차자료는 학술정보 그 자체이고 2차자료는 색인, 초록, 서지 등과 같은 1차자료를 찾아볼 수 있는 길잡이이다. 2차자료에 수록된 정기간행물의 중복된 점과 범위를 이전에 연구한 자료와 금번 조사한 자료를 비교 검토하였으며 문헌정보학분야 2차자료 Library and Information Science Abstract (LISA) : Library Literature (LL) : Information Science Abstract (ISA) 등 3가지의 주요 2차자료를 비교 분석한 결과 문헌정보학 관계 자료선정 및 장서개발 정책에 영향을 미칠 수 있음을 제시 하고있다.

• Bulletin of the Korean Chemical Society
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• 제28권7호
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• pp.1224-1226
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• 2007

• Journal of Microbiology and Biotechnology
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• 제29권5호
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• pp.667-686
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• 2019

Streptomyces are attractive microbial cell factories that have industrial capability to produce a wide array of bioactive secondary metabolites. However, the genetic potential of the Streptomyces species has not been fully utilized because most of their secondary metabolite biosynthetic gene clusters (SM-BGCs) are silent under laboratory culture conditions. In an effort to activate SM-BGCs encoded in Streptomyces genomes, synthetic biology has emerged as a robust strategy to understand, design, and engineer the biosynthetic capability of Streptomyces secondary metabolites. In this regard, diverse synthetic biology tools have been developed for Streptomyces species with technical advances in DNA synthesis, sequencing, and editing. Here, we review recent progress in the development of synthetic biology tools for the production of novel secondary metabolites in Streptomyces, including genomic elements and genome engineering tools for Streptomyces, the heterologous gene expression strategy of designed biosynthetic gene clusters in the Streptomyces chassis strain, and future directions to expand diversity of novel secondary metabolites.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권10호
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• pp.2455-2472
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• 2012

Although underlay spectrum sharing has been shown as a promising technique to promote the spectrum utilization in cognitive radio networks (CRNs), it may suffer bad secondary performance due to the strict power constraints imposed at secondary systems and the interference from primary systems. In this paper, we propose a two-phase based cooperative transmission protocol with the interference cancellation (IC) and best-relay selection to improve the secondary performance in underlay models under stringent power constraints while ensuring the primary quality-of-service (QoS). In the proposed protocol, IC is employed at both the secondary relays and the secondary destination, where the IC-based best-relay selection and cooperative relaying schemes are well developed to reduce the interference from primary systems. The closed-form expression of secondary outage probability is derived for the proposed protocol over Rayleigh fading channels. Simulation results show that, with a guaranteed primary outage probability, the proposed protocol can achieve not only lower secondary outage probability but also higher secondary diversity order than the traditional underlay case.

• 한국과학교육학회지
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• 제25권7호
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• pp.794-800
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• 2005

The purpose of this study was to examine the state of management and science teachers perception of science classes and clubs in secondary schools. There ware 125 participants (75 middle school teachers and 50 high school teachers) from eight metropolitan cities and local areas, and more than 80% of the participants had managed science classes or clubs. Results found that a significant number of science teachers felt it necessary to manage science classes and/or clubs in secondary schools. They believed the classes and/or clubs to be beneficial in the activation of students' interest in science, even though they might not be effective ways of improving scientific achievement. In addition, it was found that secondary science teachers desire financial support, in-service programs, and efficacious programs supporting science class and club management.

• Journal of Ecology and Environment
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• 제32권4호
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• pp.257-265
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• 2009

We estimated monthly and annual secondary productivity of pelagic zooplankton in Lake Paldang and Lake Cheongpyong. Secondary productivity was calculated by combining estimated zooplankton biomass and biomass-specific productivity for each site and depth from March to November 2008. In addition to somatic production, we measured production of eggs and exuviae for three dominant species: Daphnia galeata, Bosmina longirostris, Cyclops sp. In terms of biomass, B. longirostris was dominant in Lake Paldang in April and May, B. longirostris showed explosive biomass growth, especially in May. In June and July, B. longirostris and D. galeata were both dominant. Lake Cheongpyeong showed much lower zooplankton biomass than Lake Paldang. In August, there was little or no biomass in both lakes probably due to heavy rain. The Gyeongan River contributed most of the secondary productivity and B. longirostris contributed the most secondary productivity in Lake Paldang. D. galeata also contributed in the Gyeongan River, the South Han River and at the Paldang Dam in spring and fall. Overall, Lake Cheongpyeong showed lower secondary productivity than Lake Paldang. B. longirostris made the largest contribution to secondary productivity in the Cheongpyeong Dam area while D. galeata contributed the most near Nami Island. Somatic production constituted ~80% of the total secondary productivity (the sum of somatic, egg and exuvia production) for D. galeata and B. longirostris. Although production-to-biomass (P/B) ratios were usually <<1 B. longirostris sometimes showed very high P/B ratios, probably due to fish predation. D. galeata showed much lower P/B ratios than B. longirostris after the summer at most sites.