• Title/Summary/Keyword: 과부하

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An Efficient Resource Discovery Mechanism based on Distributed Location Information in Pure P2P Environments (순수 P2P 환경에서 분산된 위치 정보를 이용한 자원 검색 기법)

  • Kim In-suk;Kang Yong-hyeog;Eom Young Ik
    • Journal of KIISE:Information Networking
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    • v.31 no.6
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    • pp.573-581
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    • 2004
  • Recently, the rapid growth of Internet technology and the deployment of high speed networks make many kinds of multimedia services possible. Preexisting multimedia services are designed based on the client/server model which has the problems such as the network failure and the low speed communication due to the high load on the central server. In order to solve these problems, peer-to-peer networks are introduced and expanded through Internet environments. In this paper, we propose a pure peer-to-peer network based resource discovery mechanism for multimedia services. In the proposed scheme, each host maintains the location information of resources which are recently requested by other hosts as well as that oi the replicas of local resources. The proposed scheme has the faster response time and incurs the smaller traffic than the preexisting discovery schemes in pure peer-to-peer network environments. Also, by decentralizing the location information and differentiating the reply path, our proposed scheme can solve the search result loss problem that occurs when the network is unsettled.

Metal-Body Images in Shinya Tsukamoto's (1989) (츠카모토 신야의 <철남(鐵男)>(1989)을 통해 살펴 본 기계적-몸 이미지)

  • Kwon, Soojin;Kwon, Hajin
    • The Journal of the Korea Contents Association
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    • v.15 no.6
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    • pp.168-178
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    • 2015
  • This article analysis the aesthetics of metal-body of (1989) and its metamorphosis of dehumanization through visual desires expressed by body images. This paper suggests theoretical analysis based on aesthetic views to understand the underlying meanings. The research categorizes three types of images; surreal image, grotesque image and eros image from the metamorphosis of dehumanization and transformation throughout the film. As the surreal image, the metamorphic process of transformation, demolition, derangement, illusion, and human desire continues to reflect the evil side of a human in everyday life. It also visualizes the images of exaggeration through weakness and bizarre side of metal-body. The grotesque image of body metamorphosis displays and symbolizes double-sides of bizarre and weak side of human in the everyday environment when malformation reaches its peak when Tetsuo finally shows his transforming figure. Finally, the eros image is analogized as a man's inner self and self-destruction in surreal world and a grotesque figure when overwhelming desire of transforming into rebirth of a perfect metal-body, Tetsuo. The surreal image, grotesque image, and eros image portraits human desires inner and outer-self into visualized image and that represents the means of excessive desire for dreaming of world domination with merging non-organic medium of metal and organic body to create a perfect body-image.

A Study on the Mutual Complement between Geography Textbook and Students' Atlas as a Geographic Learning Material (지리 교육 교재로서 지리교과서와 사회과부도의 상호보완성에 대한 연구)

  • Yoon, Okkyong
    • Journal of the Korean association of regional geographers
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    • v.23 no.1
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    • pp.213-226
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    • 2017
  • Geography textbooks and atlases are typical printed materials broadly used in the classroom and the public education as certified materials. The students' atlas, as supplementary materials, is useful in teaching and learning geography in the classroom. This study examines and evaluates the supplementary role of the students' atlas in the institutional and pedagogical perspectives. The textbook and the atlas were written by different writers and publishers based on the interpretation of the geography curriculum, the pedagogical beliefs and interests. The textbook is submitted to be certificated by Ministry of Education. Then the textbook and the atlas which is passed in the certification process can be distributed to schools to use in the classroom. Most maps and materials are supplied in the textbook and the atlas variously depended on the authors' interpretation of geography curriculum, which are designed complementally. But, that maps and materials of respective book of even different author are similar and duplicated. Sometimes maps and materials of textbook and atlas are independent, not mutual complement. It needed that geography textbook and student's atlas take a efficient role supplementarily in these certification system of textbook.

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The Distribution and Standing Crop of Phytoplankton at Five Freshwater Lakes in Suwon-si and Pyongtaek-si, Gyeonggi-do (경기도 수원시와 평택시의 5개 담수호소의 식물플랑크톤 분포 및 현존량)

  • Moon Byeong-Lyeol;Nam Mi Ra;Lee Ok-Min
    • Korean Journal of Environmental Biology
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    • v.23 no.1
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    • pp.32-46
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    • 2005
  • The distribution and standing crop of the phytoplankton were investigated at five freshwater lakes Suwon-si and Pyongtaek-si, Gyeonggi-do from Mar. to Nov., 2003. In this investigation, 199 taxa in total were found and classified as 5 phylums 5 classes 16 orders 26 families 72 genera 167 species 1 subspecies 28 varieties and 3 forms by Engler's classification system. The indicator species of clean water was Cladophora glomerata, which was appeared in Gwanggyo reservoir on September, 2003. Twenty taxa including Oscillatoria chlorina were identified as the indicators of water pollution, and three taxa of cyanophyte were toxic algae. In terms of Yang and Dickman's standard of chlorophyll-a content in eutrophication of water, four lakes including Seo lake were found to be in the hypereutrophic state, and Gwanggyo reservoir was in eutrophic state except in winter.

Effect of Simple VSD Repair on Doppler-Derived Right Ventricular Systolic Time Interval (심실중격결손 봉합이 우심실 수축기 시간 간격에 미치는 영향)

  • 정태은;이영환
    • Journal of Chest Surgery
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    • v.32 no.2
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    • pp.124-129
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    • 1999
  • Background: Ventricular septal defect(VSD) that causes pulmonary hypertension increase right ventricular workload. Echocardiographic assessment of right ventricular systolic time interval (RVSTI) has been used to predict pulmonary artery pressure in various cardiopulmonary diseases. This study was undertaken in infants with simple VSD to observe the alteration of the right ventricular workload through the changes of RVSTI after repair of VSD. Material and Method: We evaluated heart rate, the ratio of the left atrium/aortic root diameter (LA/Ao), right ventricular pre-ejection period(RVPEP), right ventricular ejection time(RVET), and its ratio(RVPEP/RVET) as a predictor of right ventricular workload in 12 children with simple VSD. These were measured three times at the preoperative period, at the 3 month and between 6 month and 1 year(average 9.5${\pm}$1.8month) after repair of VSD by M-mode & Doppler echocardiograph from the pulmonic valve echogram. Result: Heart rate was decreased significantly after repair(137.1${\pm}$13.7 vs 114.4${\pm}$21.1 and 104.1${\pm}$10.2, p<0.01). LA/Ao ratio was decreased significantly after repair(1.71${\pm}$0.32 vs 1.47${\pm}$0.33 and 1.39${\pm}$0.23, p<0.05). RVPEP/RVET were decreased after repair (0.38${\pm}$0.09 vs 0.32${\pm}$0.08 and 0.29${\pm}$0.09, p<0.01). Heart rate corrected RVPEP/RVET were significantly decreased only after 6 months(0.32${\pm}$0.03 vs 0.30${\pm}$0.05 and 0.28${\pm}$0.06, p<0.05). Conclusion: We found elevated right ventricular workload was progressively decreased until more than 6 months after repair and the RVSTI may serve a useful guide in postoperative care for children with VSD.

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Design and Use of 3D-based Space Navigation System to Maintain Learner's Interest in Educational Web Contents (학습자 흥미 지속을 위한 3D-기반 공간 항해 시스템의 구현과 활용)

  • Heo, Gyun;Lee, Young-Ju;Rha, Il-Ju
    • Journal of The Korean Association of Information Education
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    • v.7 no.1
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    • pp.1-10
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    • 2003
  • Web provides a rich learning environment for learners mainly due to the hypertext technology and the high interactivity. It provides a learner-centered learning environment. In this environment, students are to develop their own paths in non-sequential and flexible ways according to their needs and their demands. However, in many cases students who use this environment are easily exposed to difficulties in their choices of learning paths, disorientation, and cognitive overload in the cyberspace. Consequently, they have trouble in maintaining their motivation and interest in their learning. This study presents the design and the use of 3D-based space navigation system in order to maintain student's interest in educational web contents.

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Usability Test of Website Navigation by Using Spatial Metaphor Concept (공간메타포 개념을 이용한 웹 사이트 네비게이션의 사용성 평가)

  • 이건창;정남호;홍노경
    • Journal of Intelligence and Information Systems
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    • v.10 no.1
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    • pp.93-107
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    • 2004
  • This study is concerned with proposing a new construct named "spatial metaphor" in the field of user interface design for web. Recently, web has been recognized as an important vehicle of delivering messages and information to customers. Since both hyperlink and multimedia technology are crucial part of web, its user interface requires a new approach to enhance user's acceptance of web. In this sense, we introduced a new concept named "spatial metaphor" instead of hierarchical menus. As a theoretical basis, Davis (1986)'s TAM(Technology Acceptance Model) was used to test the statistical validity of the proposed spatial metaphor. For test web site, we developed a prototype designed by using atomic-web system and spatial metaphor. By using the prototype, we built a web-based questionnaire system so that respondents can use it directly before answering the questionnaire. To prove its statistical validity, we collected valid questionnaires and tested with LISREL. In this way, statistical validity of our proposed approach was proven.approach was proven.

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A Scheduling Algorithm for Continuous Media (연속미디어를 위한 스케쥴링 알고리즘)

  • 유명련;안병철
    • Journal of Korea Multimedia Society
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    • v.4 no.5
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    • pp.371-376
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    • 2001
  • Since continuous media such as video and audio data are displayed within a certain time constraint, their computation and manipulation should be handled under limited condition. Traditional real-time scheduling algorithms cold be directly applicable, because they are not suitable for multimedia scheduling applications which support many clients at the same time. Rate Regulating Proportional Share Scheduling Algorithm based on the stride scheduler is a scheduling algorithm considered the time constraint of the continuous media. The stride schedulers, which are designed to general tasks, guarantee the fairness of resource allocation and predictability. The key concept of RRPSSA is a rate regulator which prevents tasks from receiving more resource than its share in a given period. But this algorithm loses fairness which is a strong point of the stride schedulers, and does not show graceful degradation of performance under overloaded situation. This paper proposes a new modified algorithm, namely Modified Proportional Share Scheduling Algorithm considering the characteristics of multimedia data such as its continuity and time dependency. Proposed scheduling algorithm shows graceful degradation of performance in overloaded situation and it reduces the scheduling violations up to 70% by maintaining the fair resource allocation. The number of context switching is 8% less than RRPSSA and the overall performance is increased.

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A Dynamic Bandwidth Tuning Mechanism for DQDB in Client-Server Traffic Environments (클라이언트-서버 트래픽 환경에서 분산-큐 이중-버스의 동적 대역폭 조절 방식)

  • Kim, Jeong-Hong;Kwon, Oh-Seok
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.11
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    • pp.3479-3489
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    • 2000
  • Most of the study on fairness control method for Distributed-Queue Dual-Bus(DQDB) have been performed under specific load types such as equal probability load types or symmetric load types. On Web-based internet enviroments client-server load types are more practical traffic patlerns than specrfic load types. In this paper, an effiective fairness control method to distribute DQDR network bandwidth fairly to all stations under a client-server load is proposed. In order to implement a dynamic bandwidth timing capabihty needed to distribute the bandwidth fairty at heavy loads, the proposed method uses two pararnetexs, one is an access hrnit to legulate each station's packet transmission and the other is the number of extra emply slots that are yielded to downstream stations. In point of implementation this mechanism is simpler and easier than Bandwidth Tuning Mechanism(BTM) that uses an intermediate pattern and an adptation function. Simulation results show that it outperforms othen mecharusms.

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Knowledge Reasoning Model using Association Rules and Clustering Analysis of Multi-Context (다중상황의 군집분석과 연관규칙을 이용한 지식추론 모델)

  • Shin, Dong-Hoon;Kim, Min-Jeong;Oh, SangYeob;Chung, Kyungyong
    • Journal of the Korea Convergence Society
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    • v.10 no.9
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    • pp.11-16
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    • 2019
  • People are subject to time sanctions in a busy modern society. Therefore, people find it difficult to eat simple junk food and even exercise, which is bad for their health. As a result, the incidence of chronic diseases is increasing. Also, the importance of making accurate and appropriate inferences to individual characteristics is growing due to unnecessary information overload phenomenon. In this paper, we propose a knowledge reasoning model using association rules and cluster analysis of multi-contexts. The proposed method provides a personalized healthcare to users by generating association rules based on the clusters based on multi-context information. This can reduce the incidence of each disease by inferring the risk for each disease. In addition, the model proposed by the performance assessment shows that the F-measure value is 0.027 higher than the comparison model, and is highly regarded than the comparison model.