• 제목/요약/키워드: Group shared key

검색결과 50건 처리시간 0.025초

Lipase Diversity in Glacier Soil Based on Analysis of Metagenomic DNA Fragments and Cell Culture

  • Zhang, Yuhong;Shi, Pengjun;Liu, Wanli;Meng, Kun;Bai, Yingguo;Wang, Guozeng;Zhan, Zhichun;Yao, Bin
    • Journal of Microbiology and Biotechnology
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    • 제19권9호
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    • pp.888-897
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    • 2009
  • Lipase diversity in glacier soil was assessed by culture-independent metagenomic DNA fragment screening and confirmed by cell culture experiments. A set of degenerate PCR primers specific for lipases of the hormone-sensitive lipase family was designed based on conserved motifs and used to directly PCR amplify metagenomic DNA from glacier soil. These products were used to construct a lipase fragment clone library. Among the 300 clones sequenced for the analysis, 201 clones encoding partiallipases shared 51-82% identity to known lipases in GenBank. Based on a phylogenetic analysis, five divergent clusters were established, one of which may represent a previously unidentified lipase subfamily. In the culture study, 11 lipase-producing bacteria were selectively isolated and characterized by 16S rDNA sequences. Using the above-mentioned degenerate primers, seven lipase gene fragments were cloned, but not all of them could be accounted for by the clones in the library. Two full-length lipase genes obtained by TAIL-PCR were expressed in Pichia pastoris and characterized. Both were authentic lipases with optimum temperatures of ${\le}40^{\circ}C$. Our study indicates the abundant lipase diversity in glacier soil as well as the feasibility of sequence-based screening in discovering new lipase genes from complex environmental samples.

오버레이 링을 이용한 이동 에이전트 간의 안전한 그룹 통신 기법 (A Secure Group Communication Scheme for Mobile Agents using the Hierarchical Overlay Ring)

  • 정용우;최정환;고광선;김구수;엄영익
    • 정보처리학회논문지A
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    • 제14A권6호
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    • pp.333-340
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    • 2007
  • 일반적인 멀티에이전트 시스템에서 에이전트들 간의 통신 기능을 지원하기 위한 다양한 모델들이 제안되어 왔으며, 특히, 그룹 통신 기능을 지원하기 위한 다양한 기법들이 제시되어 있다. 그러나, 이동 에이전트 환경에서는 에이전트의 이주로 인해 발생하는 토폴로지의 변화를 고려한 새로운 그룹 통신 기법을 필요로 하며, 더불어 이러한 그룹 통신 기능의 안전성을 보장하는 기법이 필요하게 된다. 본 논문에서는 계층적 오버레이 링을 이용한 이동 에이전트들 간의 안전한 그룹 통신 기법을 제안하며, 이 기법은 이동 에이전트의 이주에 따른 토폴로지의 변화에 유연하게 대응하기 위해 링 채널을 이용한다. 여기서 링 채널은 이동 에이전트들 간의 링 토폴로지를 구성하기 위한 객체로서 이동 에이전트 플랫폼에 의해서만 관리되며, 이에 따라 이동 에이전트들은 링 채널을 직접 관리할 필요가 없게 되고, 이주에 의해 발생하는 링 토폴로지 변화에 대한 고려 없이 그룹 통신을 진행할 수 있게 된다.

소셜 네트워크 시대의 세대 간 소통 증감 인식차이에 대한 탐색적 연구 (Exploring Differing Communication among Generation in a Social Network Age)

  • 박기호
    • Journal of Information Technology Applications and Management
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    • 제24권1호
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    • pp.11-24
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    • 2017
  • Due to development of smart and network technologies, social network service (SNS) has become popular in daily life. With increasing use of SNS, the scope of communication has been widened. Lots of activities can be easily shared daily on SNS. Differing with opinions about more activated communication on SNSs, some people have viewpoints that, in some cases, communications may be decreased among SNS users. This research is to investigate whether there may be the differences among generations in the social network age. Major concerns of study are as follows. First, there may be differences in age related to the decrease of communication activities. On the other hand, there may be differences among generations related to the increase of communication. Two research steps have been adopted that the FGI (focus group interview) was to understand. Defining actual communication status was the first step, and an empirical approach, a survey to verify hypotheses, was performed as the second step. Key findings of the study were that older generations perceived communication has been decreased. Research results can provide implications regarding characteristics of SNS communication.

Mapping QTLs for Tissue Culture Response of Mature Wheat Embryos

  • Jia, Haiyan;Yi, Dalong;Yu, Jie;Xue, Shulin;Xiang, Yang;Zhang, Caiqin;Zhang, Zhengzhi;Zhang, Lixia;Ma, Zhengqiang
    • Molecules and Cells
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    • 제23권3호
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    • pp.323-330
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    • 2007
  • The mature wheat embryo is arguably one of the best explants for genetic transformation because of its unlimited availability and lack of growth season restriction. However, an efficient regeneration system using mature wheat embryos (Triticum aestivum L.) is still not available. To identify genes related to the tissue culture response (TCR) of wheat, QTLs for callus induction from mature embryos and callus regeneration were mapped using an RIL population derived from the cross of 'Wangshuibai' with 'Nanda2419', which has a good TCR. By whole genome scanning we identified five, four and four chromosome regions conditioning, respectively, percent embryos forming a callus (PEFC), percent calli regenerating plantlets (PCRP), and number of plantlets per regenerating callus (NPRC). The major QTLs QPefc.nau-2A and QPcrp.nau-2A were mapped to the long arm of chromosome 2A, explaining up to 22.8% and 17.6% of the respective phenotypic variance. Moreover, two major QTLs for NPRC were detected on chromosomes 2D and 5D; these together explained 51.6% of the phenotypic variance. We found that chromosomes 2A, 2D, 5A, 5B and 5D were associated via different intervals with at least two of the three TCR indexes used. Based on this study and other reports, the TCRs of different explant types of wheat may be under the control of shared or tightly linked genes, while different genes or gene combinations may govern the stages from callus induction to plantlet regeneration. The importance of group 2 and 5 chromosomes in controlling the TCRs of Triticeae crops and the likely conservation of the corresponding genes in cereals are discussed.

Oncologists Experience with Second Primary Cancer Screening: Current Practices and Barriers and Potential Solutions

  • Shin, Dong-Wook;Kim, Yeol;Baek, Young-Ji;Mo, Ha-Na;Choi, Jin-Young;Cho, Ju-Hee
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권2호
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    • pp.671-676
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    • 2012
  • Objectives: Screening for second primary cancer (SPC) is one of the key components of cancer survivorship care. The aim of the present study was to explore oncologists' experience with promoting second primary cancer screening. Methods: Two focus group interviews were conducted with 12 oncologists of diverse backgrounds. Recurrent issues were identified and placed into thematic categories. Results: Most of the oncologists did not consider SPC screening promotion as their responsibility and did not cover it in routine care. All of the study participants had experience with unexpected SPC cases, and they were under emotional tress. There was no systematic manner of providing SPC screening. Oncologists usually prescribe SPC screening in response to patients' requests, and there was no active promotion of SPC screening. Short consultation time, limited knowledge about cancer screening, no established guideline for SPC screening, and disagreement with patients about oncologists' roles were major barriers to its promotion. An institution-based shared care model was suggested as a potential solution for promoting SPC screening given current oncology practices in Korea. Conclusion: Oncologists could not effectively deal with the occurrence of SPC, and they were not actively promoting SPC screening. Lack of knowledge, limited health care resources, and no established guidelines were major barriers for promoting SPC screening to cancer survivors. More active involvement of oncologists and a systematic approach such as shared-care models would be necessary for promoting SPC screening considering increasing number of cancer survivors who are vulnerable.

Intermedia Synchronization Protocol for Continuous Media Using MPEG-4 in Mobile Distributed Systems

  • Dominguez, Eduardo Lopez;Hernandez, Saul Eduardo Pomares;Gil, Pilar Gomez;Calleja, Jorge De La;Benitez, Antonio;Marin-Hernandez, Antonio
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제6권6호
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    • pp.1689-1706
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    • 2012
  • The preservation of temporal dependencies among a group of processes that exchange continuous media at runtime is a key issue for emerging mobile distributed systems (MDS), such as monitoring of biosignals and interactive multiuser games. Although several works are oriented to satisfy temporal dependencies, most of them are not suitable for MDSs. In general, an MDS is characterized by the absence of global references (e.g. shared memory and wall clock), host mobility, limited processing and storage capabilities in mobile hosts, and limited bandwidth on wireless communication channels. This paper proposes an asymmetric synchronization protocol to be used at runtime in an MDS without using a common reference. One main aspect of our synchronization protocol is that it translates temporal constraints to causal dependencies of the continuous media data as seen by the mobile hosts. We simulate the protocol by considering a cellular network environment and by using MPEG-4 encoders. The simulation results show that our protocol is effective in reducing the synchronization error. In addition, the protocol is efficient in terms of processing and storage costs at the mobile devices, as well as in the overhead attached per message across the wired and wireless channels.

소매업체의 글로벌 확장전략과 공급사슬관리에 관한 연구: 메트로 그룹을 중심으로 (A Study on the Retailer's Global Expansion Strategy and Supply Chain Management : Focus on the Metro Group)

  • 김동윤;문미진;이상윤
    • 유통과학연구
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    • 제11권12호
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    • pp.25-37
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    • 2013
  • Purpose - The structure of retailing has changed as retailers develop markets in response to business environment changes. This study aims to analyze the general situation of retailers in order to predict future global strategy using case studies of overseas expansion strategy and the Metro Group's global strategy. Research design, data, and methodology - The backgrounds to the new retail business model and retailer classification are analyzed as theoretical data. In addition, the key success point of the Metro Group's "cash and carry" strategy is analyzed as is the Metro Group's global CFAR (collaborative planning, forecasting, and replenishment) strategy. Finally, the plan for cooperation and precise forecasting under the Metro Group's supply chain management are analyzed from the promotion environment viewpoint. Related materials analyzed included the 2012 annual report, the Metro Group's web page, and a video interview with the executive in charge of global strategy and the new market development department. Some data were revised to avoid disrupting essential aspects of the case studies. Results - The important finding was that the Metro Group could be a world-class retail company with its successful global expansion strategy. The Metro Group's global strategy's primary goal is to have a leading business position in Eastern and Western Europe. The "cash and carry" strategy is highest priority in its overseas expansion strategy. Moreover, the Metro Group has standardized product planning capacity, which could be applied in various countries with different structural and cultural backgrounds. This is the main reason that the Metro Group could rapidly become successful in the Eastern Europe and Asian markets through its structural overseas expansion strategies. In addition, the Metro Group emphasizes the importance of supply chain management. Conclusions - First, retailers should create additional value through utilizing the domestic market, market power, and economies of scale to launch a global strategy to maximize benefits from diversification. Second, the political, economic, and cultural background of the target country needs to be understood to successfully implement the overseas expansion strategy. Third, the main factor of successful cooperation with a local partner is how quickly the company gains total understanding of the business resources and core competence of its partner. All organizations should focus on the achievement of goals in order to successfully operate the partnership. Fourth, retailers should improve their business, financial and organizational structure. Moreover, the work processes and company culture should also be improved to respond strongly in the competitive global market. Fifth, the essential point of a successful retail business is the control capacity of its branding and format. The retailer could avoid forecasting errors through supply chain management by perfectly distributing the actual amount of its inventory. In addition, the risks along the supply chain are effectively shared between the supply chain partners. Finally, the central tendency of the market is to gain in strength with this taking place across all parts of the business.

아동학대 범죄의 처벌 등에 관한 특례법 전후의 아동학대 인식 변화에 대한 고찰 (A Study on the Change of Perceptions of Child Abuse Before and After Special Law)

  • 이경은;김도희
    • 한국콘텐츠학회논문지
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    • 제19권9호
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    • pp.629-636
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    • 2019
  • 아동학대 범죄의 처벌 등에 관한 특례법이 실제 우리 사회에서 아동학대에 대해 공유 되어 지는 사회적 인식변화를 가져왔는지를 추론하기 위해 빅 데이터를 활용하여 대중의 아동학대 인식변화를 살펴보았다. 본 연구는 '아동학대'를 키워드로 선정하여 특별법 시행 전후 분석한 결과는 아래와 같다. 첫째, 2013년 특별법 시행 이전에는 유치원, 교사, 신체, 문제, 신고 의무, 방임 등이 이후와 비교하여 차이나는 단어들이다. 특별법 시행 이후에는 어린이집, 사건, 근절, 캠페인, 가정폭력, 예방 교육 등이 새롭게 나타났다. 둘째 핵심어들의 상호연관성은 2013년 이전 그림에서 II 집단은 아동학대를 방지하기 위한 방안 위주로 나타나고, III 집단은 아동학대를 가정폭력과 연계하여 가정 내의 문제로 인식하는 이혼, 훈육, 방치, 부모교육들이 보여진다. 2013년 특례법 이후에는 4개 그룹으로 세분화 되고 아동학대 사건에 대해 특례법과 아동보호체계가 구체적으로 나타나는 등 강화된 인식을 보여주고 있다.

스마트카드를 이용한 프록시 재 암호화 기법 기반 콘텐츠 공유 메커니즘에 관한 연구 (A Study on Contents Sharing Mechanism based on Proxy Re-Encryption Scheme using the Smart Card)

  • 박승환;구우권;김기탁;문혜란;이동훈
    • 정보보호학회논문지
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    • 제21권3호
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    • pp.131-141
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    • 2011
  • OMA(Open Mobile Alliance 는 모바일 디바이스 분야에서 DRM 기술에 대한 가장 활발한 표준화 활용을 벌이고 있으며, 2007년에는 OMA-DRM v2.1 표준을 발표하였다. 이후 2009년에는 OMA-DRM v2.1의 확장이라고 할 수 있는 OMA-SRM(Secure Removable Media)과 SCE (Secure Contents Exchange)등 DRM 기술과 공유 모델에 대한 표준을 발표하였다. SCE는 사용자도메인을 구성하여 OMA-DRM v2.1에서 정의된 모바일 디바이스뿐만 아니라 일반 가전기기(Phone, PC, 카오디오 등)간의 콘텐츠 및 권리(Rights)를 공유할 수 있다. 본 논문에서는 OMA-DRM과 ACE의 기술과 공유 모델에 대하여 분석을 하고, 프록시 재 암호기법을 사용하여 공유된 콘텐츠와 권리를 이용하기 위한 각 개체들의 키 분배방법을 제시하고자 한다.

플립러닝 기반 SSI 수업이 중학생의 과학기술 사회 시민으로서의 역량 및 인성 함양에 미치는 효과 (Flipped Learning in Socioscientific Issues Instruction: Its Impact on Middle School Students' Key Competencies and Character Development as Citizens)

  • 박동화;고연주;이현주
    • 한국과학교육학회지
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    • 제38권4호
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    • pp.467-480
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    • 2018
  • 본 연구는 플립러닝을 적용한 과학관련 사회쟁점 교수학습(FL-SSI)이 중학생의 시민역량과 인성발달에 미치는 영향을 탐색하는 것을 목적으로 하였다. 플립러닝은 교실 수업 전 교수학습 영상을 제공하여 기초 개념과 문제인식의 기회를 제공하고, 교실 수업에서는 이를 바탕으로 한 토의토론 활동을 진행함으로써 학생들이 보다 역동적이고 협력적으로 수업에 참여할 수 있도록 하는 전략이다. 이에 본 연구에서는 전통적인 SSI 수업에서 보고되는 시간과 정보의 제약이나 토의 토론 진행 등의 어려움을 해결하고자 플립러닝 전략에 기초한 과학관련 사회쟁점 교수학습 프로그램을 개발 및 적용하였다. 본 연구에는 중학교 2학년 학생 73명이 네 가지 주제의 12차시 수업으로 구성된 SSI 교수학습 프로그램에 참여하였다. 학생들은 매 차시 수업 전 교사가 웹에 게시한 동영상을 시청한 후, 본 수업에서는 영상에 대한 이해를 바탕으로 다양한 학생중심 활동에 참여하였다. 학생들은 수업 전후 과학기술 사회의 시민역량과 글로벌 시민으로서 갖추어야 할 인성을 측정하는 검사지에 응답하였으며, 수업 이후 포커스 그룹 면담에 참여함으로써 학생들이 인식한 플립러닝 기반 과학관련 사회쟁점 교수학습의 효과를 살펴보았다. 연구 결과, 플립러닝 기반 SSI 수업에 참여한 학생들의 시민역량과 인성은 수업 후 통계적으로 유의한 향상이 있었다. 특히 학생들은 시민역량의 네 영역(협업능력, 정보기술 및 미디어 활용능력, 비판적 사고와 문제해결능력, 의사소통능력) 모두에서 통계적으로 유의한 향상이 있었으며, 인성의 세 영역 중 두 영역(사회도덕적 공감, 과학관련 사회쟁점에 대한 책무성) 영역에서 유의한 향상이 있었다. 포커스 그룹면담 결과 또한 학생들이 SSI 수업에 플립러닝을 적용한 효과를 긍정적으로 인식하였음을 뒷받침하였다. 학생들은 플립러닝 전략을 통해 SSI 문제 상황에 대한 이해를 높였으며, 자료탐색과 의사결정의 시간을 절약함으로써 교실 수업 시간을 SSI 문제 상황을 해결하는 데 온전하게 활용하였다. 또한 SSI 문제를 둘러싼 다양한 관점에 대해 이해할 수 있는 충분한 기회를 가질 수 있었다. 본 연구는 플립러닝 전략이 기존의 SSI 수업에서의 어려움을 보완하고 개선함으로써, SSI 수업을 효과적으로 운영할 수 있는 한 방안이 될 수 있음을 보여준다.