• 한국전자통신학회논문지
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• 제2권1호
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• pp.46-51
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• 2007

무선 환경에서 P2P 환경에서의 파일 공유 방식은 클라이언트/서버 방식과는 다르게 값비싼 서버를 사용하지 않고 클라이언트 컴퓨터들만을 사용하여 자료의 공유 및 관리를 분산시킨다. 이러한 이유로 대용량의 서버를 사용하는 클라이언트/서버 방식에서 발생하는 인적, 물적 자원의 낭비를 최소화 할 수 있다. 또한 사용자의 수가 늘어날수록 연산, 협업의 성과가 높아지는 등의 혜택을 제공한다. 이와 같은 이유로 인해 많은 사람들이 P2P에 관심을 갖고, 또한 현재 각광받고 있는 모바일 관련 분야에도 P2P를 이용한 연구들이 활발하게 진행되고 있다.

• 한국전자통신학회논문지
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• 제1권1호
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• pp.36-41
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• 2006

무선 환경에서 P2P 환경에서의 파일 공유 방식은 클라이언트/서버 방식과는 다르게 값비싼 서버를 사용하지 않고 클라이언트 컴퓨터들만을 사용하여 자료의 공유 및 관리를 분산시킨다. 이러한 이유로 대용량의 서버를 사용하는 클라이언트/서버 방식에서 발생하는 인적, 물적 자원의 낭비를 최소화 할 수 있다. 또한 사용자의 수가 늘어날수록 연산, 협업의 성과가 높아지는 등의 혜택을 제공한다. 본 연구에서는 모바일 P2P 서비스를 영농정보 공유, 재해 정보의 통계 및 분석을 위한 프로그램에 응용하였다.

• 대한불안의학회지
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• 제18권2호
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• pp.56-64
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• 2022

Objective : Creating a psychologically stable indoor environment is a significant factor in modern life. This study was conducted to confirm which type of wood interior decorating environment was beneficial for improving depression and anxiety. Methods : A total of 59 participants will randomly assign to each accommodation by dividing the rest of the three setting with the same structure with 0% wood interior decorating environment, 45% wood environment, and 90% wood environment. The Psychological evaluation measured at three time points, was before exposure to the wood environment (T1), 45 minutes after exposure to the wood environment (T2), and 20 hours after exposure to the wood environment (T3). Results : As a result of examining the effect of the wood interior use ratio on psychological variables, After about 20 hours (T3), there were significant differences in mood state_vigor-activity(𝛘²=7.253, p<0.05), mood state_tension-anxiety (𝛘²=7.041, p<0.05), mood state_anger-hostility(𝛘²=8.318, p<0.05), and state anxiety (𝛘²=7.680, p<0.05). State anxiety also showed a significant difference in T2 (𝛘²=8.811, p<.05). As a result of analyzing the effect on satisfaction and subjective impression, there was a significant difference in satisfaction (𝛘²=6.300, p<0.05) and 'pleasant (𝛘²=6.930, p<0.05), airy (𝛘²=6.628, p<0.05), masculine (𝛘²=6.906, p<0.05), ordinary(𝛘²=6.662, p<0.05), natural (𝛘²=13.924, p<0.001), calm (𝛘²=13.106, p<0.001), safe (𝛘²=7.755, p<0.05)'. Conclusion : The wood interior decorating environment had a positive effect on anxiety and mood, such as lowering depressive and anxious mood and increasing positive changes and as the ratio of wood decoration increased, it had a greater positive effect on emotions.

• 디지털산업정보학회논문지
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• 제7권4호
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• pp.1-6
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• 2011

In this paper, search-efficient Bi-directional-Chord(B-Chord) is proposed in P2P (peer-to-Peer) overlay network. Chord is the most popular P2P Look-up protocol. However, it applied to the mobile environment, the search success rate become lower and the request delay time increases. That is big problem. Thus, by improving the existing Chord, in this paper proposed B-Chord reduces the request delay time to in a mobile environment. Proposed B-Chord have the two Finger table and can search by selecting Finger table depending on the value of Key. By use these bi-directional, it can reduce the number of nodes Hop and search delay time. Thus, As a result, it will be able to increase the search success rate in a mobile environment.

• 디지털산업정보학회논문지
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• 제6권4호
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• pp.11-20
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• 2010

Ontology is important role in semantic web to construct and query semantic data. Because of dynamic characteristic of ontology, P2P environment is considered for ontology processing in web environment. For efficient processing of ontology in P2P environment, clustering of peers should be considered. When new peer is added to the network, cluster allocation problem of the new peer is important for system efficiency. For clustering of peers with similar chateristics, similarlity measure method of ontology in added peer with ontologies in other clusters is needed. In this paper, we propose similarity measure techniques of ontologies for clustering of peers. Similarity measure method in this paper considered ontology's strucural characteristics like schema, class, property. Results of experiments show that ontologies of similar topics, class, property can be allocated to the same cluster.

• 한국환경과학회지
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• 제26권11호
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• pp.1255-1266
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• 2017

Phosphorus (P) is an essential and major nutrient for both plants and animals. However, anthropogenic P in the environment may cause severe problems such as the deterioration of water quality. Therefore, it is essential for the Korean government to manage P in the agricultural sector. The annual P budget for Korea was 46 kg P ha-1 in 2013, placing Korea in second among Organisation for Economic Co-operation and Development (OECD) countries. P surplus and deficiency in agricultural lands can be estimated according to the P budget, which is one of the OECD agri-environment indicators. In the P budget, it is important to ensure consistency in the input-output data sources, in order to apply national and regional policies for the environmentally sound management of agricultural P. This study examines the impacts on the input-output data sources in the regional P budget in Korea. P budgets were between 99-145 kg-P/ha, depending on different data sources. We suggest two recommended data combinations (DC 1 and DC 2) for reliability of the data. P budgets calculated using DC 1 and DC 2 were 128 kg-P/ha and 97 kg-P/ha, respectively. According to the results, one of the core factors affecting P budgets was crop production. In this study, DC 2 was recommended rather than DC 1 in order to consider the cultivated areas for various crops. It is also necessary to analyze the sensitivity of the coefficients used in P budget in the future.

• 한국통신학회논문지
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• 제34권7B호
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• pp.728-733
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• 2009

유비쿼터스 환경은 피어간의 연결, 이동이 전제되는 환경 등의 특정을 가지고 있다. 이러한 특정은 peer-to-peer(P2P) 시스템과 이동 애드혹 네트워크 (MANET)로 표현될 수 있다. P2P 시스템과 MANET은 비슷한 특징이 많이 있어 MANET 환경에서 P2P 시스템 구현은 매력적이다. 그러나 유선망에서 디자인된 P2P 시스템을 그대로 MANET에 적용하는 경우 성능이 만족스럽지 못하다는 것이 연구결과로 입증되었다. 이에 본 논문에서는 cross-layer 디자인을 사용하고 피어의 양호성을 고려하여 MANET 환경에서 만족스러운 성능을 낼 수 있는 P2P 시스템을 제안한다. 제안된 시스템은 라우팅 에트릭과 P2P 에트릭을 시용하여 연결을 유지할 피어를 선택하고, 피어 정보를 능동적으후 전달한다. 모의실험 결과, 제안한 방안은 라우팅 경로를 줄임으로써 쿼리 성공률, 쿼리 응답시간, 에너지 소모량에서 좋은 성능을 보여주었다.

• 방사선산업학회지
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• 제5권4호
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• pp.353-357
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• 2011

Degradation of p-nitrophenol has been carried out using only gamma irradiation or gamma irradiation with $H_2O_2$ or $Na_2S_2O_8$. Effects of different operating parameters such as initial concentration ($50mg\;l^{-1}$, $100mg\;l^{-1}$, $200mg\;l^{-1}$, $300mg\;l^{-1}$, $400mg\;l^{-1}$, $500mg\;l^{-1}$ and $600mg\;l^{-1}$) on the extent of degradation has been investigated. At 5 kGy, $50mg\;l^{-1}$ p-nitrophenol was completely degraded, and the radiolytic degradation of p-nitrophenol was described by the pseudo-first-order kinetic model. The combination of gamma irradiation with $H_2O_2$ or $Na_2S_2O_8$ leads to an enhanced effect, which remarkably increased the degradation efficiency of p-nitrophenol and TOC removal. However, at high $H_2O_2$ concentration, the efficacy of p-nitrophenol degradation is reduced because ${\cdot}OH$ radicals are scavenged by $H_2O_2$ and $Na_2S_2O_8$.

• 지역사회간호학회지
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• 제1권1호
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• pp.503-517
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• 1989

This study is to analyze factors affecting the school nurse's activities. The survey was undertaken during Sept. 1-Nov. 30, 1986. The subjects were 137 school nurses from elementary, junior-high, and senior-high schools in Daegu City and Kyungppk Province. The results are as follows: 1. Correlational findings between school nurse's self-confidence and their general characteristics 1) Program Planning & Evaluation: Health Experinece(r=-0.1803, p<0.05) Salary Step(r=-0.1741, p<0.05) 2) Clinic Management: Salary STep(r=-0.2580, p<0.01) 3) Health Education: Salary Step(r=-0.1929, p<0.05) 4) Management of School Environment: Salary Step(r=-0.2501, p<.05) 5) Health Care Services: Health Experience(r=0.1901, p<0.05) Salary Step(r=-0.2424, p<0.05) 2. The degrees of school nurse's self-confidence(high: 4 point, low: 1 point) 1) Clinic Management: 2.92 2) Health Education: 2.86. 3) Program Planning & Evaluation: 2.74 4) Health Care Services: 2.73 5) Management of School Environment: 2.67 6) Operating of School Health Organization: 2.42 3. Significances to self-confidence on school nurse's activities 1) Program Planning as Evaluation: Expending Times for Health Care Services (r=-0.2262, p<0.05) Expending Times for Health Education (r=0.2943, p<0.05) Size of Clinic(r=0.2163, p<0.05) Location of Clinic(t=2.43, gH0.047) Use of Clinic(t=2.06, p<0.007) 2) Clinic Management: Location of Clinic (t=3.36, p<0.010) 3) Health Education: Purchase of Medicine(r=-0.1736, p<0.05) No, of Classes (r=-0.1794, p<0.05) (4) Management of School Environment: School Health Budget(r=0.1731, p<0.05) Home Message(r=0.1805, p<0.05) Location of Clinic(t=4.46, p<0.0001) 5) Operating of School Health Organization: School Health Budget(r=0.1878, p<0.05) Use of Clinic(t:1.90, p<0.018) 6) Health Care Services: School Health Budget(r=1.90, p<0.018) Expending Times for Health Education(r=0.2577, p<0.05) Size of Clinic(r=0.4336, p<0.001) Location of Clinic(t:5.10, p<0.001)

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 추계종합학술대회
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• pp.545-548
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• 2005

최근 들어 클라이언트/서버 컴퓨팅 환경에서 서버의 과도한 부하 문제를 해결하고자 P2P 컴퓨팅 환경이 대두되고 있다. 현재 실용화 되어 운영중인 P2P 컴퓨팅 환경은 주로 파일 출판자/송신자/수신자의 실명기반 혹은 익명기반의 P2P 시스템으로 전개되고 있다. 하지만, 어떤 환경에서건 현재의 파일 보호는 파일 단위 기반의 보안기술이 적용됨에 따라 첫째, 적의 공격목표가 특정 단일 호스트라는 취약점을 지니게 되고, 둘째, 취득된 파일에 대해 Brute Force 공격이 용이하고, 셋째, DOS공격 목표를 명료하게 하는 등의 문제점을 지니고 있다. 본 논문에서는 이러한 문제점 해결책으로 파일을 블록단위로 분리하고 각 블록을 피어들에게 안전하게 분산시켜 이를 활용하는 분산 P2P 파일분리 시스템을 새롭게 제안하였다. 제안 시스템은 파일이 블록 단위로 인코딩되어 각 피어로 분산됨에 따라 상기의 3가지 문제점을 해결할 뿐만 아니라 파일 활용의 효율성을 증진시키는 부대 효과를 얻을 수 있다.