• Title/Summary/Keyword: peer-to-peer

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Why Web-based Peer Assessment is Needed?

  • KIM, Minjeong
    • Educational Technology International
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    • v.6 no.2
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    • pp.131-151
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    • 2005
  • As student-centered learning grows, formative peer assessment practices have been universally used in various fields. According to the review of traditional peer assessment practices, the formative peer assessment has five common stages: planning, assessing (giving feedback), receiving feedback, reflection, and revising. As the each stage of traditional formative peer assessment has some weaknesses, the study discusses solutions that are recommended for dealing with the problems by introducing the potential benefits of web-based peer assessment. Then, desirable future trends of web-based peer assessment are suggested. The author hopes that understanding the potential benefits of web-based formative peer assessment will promote the proper use of peer assessment and render positive effect on student learning.

Developmental Trajectories for Peer Rejection in Preschool Children Based on Latent Growth Model (잠재성장모형을 적용한 유아기 또래거부의 발달궤적)

  • Shin, Yoo Lim
    • Human Ecology Research
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    • v.54 no.6
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    • pp.565-574
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    • 2016
  • This research examined the trajectories of peer rejection in preschool children. This study also investigated the gender differences in the intercept and slope of the trajectories for peer rejection along with the influences of aggression, withdrawal and language ability on the trajectories of peer rejection. A latent growth curve model investigated peer rejection in 3 to 5 year olds. Three hundred and thirteen 3-year-old children were recruited from five preschools and 14 daycare centers. The children's language ability was measured by a Wechsler Preschool and Primary Scale of intelligence verbal test and teachers completed measurements for aggression and withdrawal. A peer nomination inventory was used to assess peer rejection. Children were asked to nominate three classmates who they do not like to play with. The research findings showed that peer rejection decreased during the preschool years. Compared with girls, boys showed higher levels of peer rejection and a slower change rate of peer rejection. Girls who were aggressive showed high levels of peer rejection and a slow change rate of peer rejection. Moreover, girls who had a high levels language showed low levels of peer rejection and a slow change rate of peer rejection. These findings imply that language ability could be a protective factor of peer rejection for girls.

Efficient Peer Assignment for Low-Latency Transmission of Scalable Coded Images

  • Su, Xiao;Wang, Tao
    • Journal of Communications and Networks
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    • v.10 no.1
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    • pp.79-88
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    • 2008
  • In this paper, we propose efficient peer assignment algorithms for low-latency transmission of scalable coded images in peer-to-peer networks, in which peers may dynamically join and leave the networks. The objective of our algorithm is to minimize the transmission time of a requested image that is scalable coded. When an image is scalable coded in different bit rates, the bit stream encoded in a lower bit rate is a prefix subset of the one encoded in a higher bit rate. Therefore, a peer with the same requested image coded in any bit rate, even when it is different from the requested rate, may work as a supplying peer. As a result, when a scalable coded image is requested, more supplying peers can be found in peer-to-peer networks to help with the transfer. However, the set of supplying peers is not static during transmission, as the peers in this set may leave the network or finish their transmission at different times. The proposed peer assignment algorithms have taken into account the above constraints. In this paper, we first prove the existence of an optimal peer assignment solution for a simple identity permutation function, and then formulate peer assignment with this identity permutation as a mixed-integer programming problem. Next, we discuss how to address the problem of dynamic peer departures during image transmission. Finally, we carry out experiments to evaluate the performance of proposed peer assignment algorithms.

An Efficient Peer-to-Peer Web Caching Model with the Dynamic Participation of Peers (네트워크 동적 참여 기반의 효율적인 피어-투-피어 웹 캐슁 모델)

  • Ryu Young-Suk;Yang Sung-Bong
    • Journal of KIISE:Information Networking
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    • v.32 no.6
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    • pp.705-715
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    • 2005
  • A peer-to-peer web caching has been studied recently as it can reduce the traffic converged on the server side and can support the traditional web caching model. Although the peer-to-peer web caching has the merit of having additional cache space from the local caches of peers without additional infrastructure, several constraints such as dynamic participation and local caching strategy caused by the autonomy of peers in peer-to-peer networks nay limit the performance of the peer-to-peer web caching. To overcome these limitations, we propose an efficient directory-based peer-to-peer web caching system under dynamic participation of peers. In the proposed caching system, we present new peer selection and replica management schemes by introducing the concept of the object lifetime in P2P networks. We evaluate the effectiveness of the proposed system through trace-driven simulations with a web log dataset. Simulation results show that the proposed system has higher accuracy and fewer redirection failures than the conventional directory-based P2P web caching system in feasible peer-to-peer networks.

An Intelligent Performance based Hybrid P2P System for Distributed Resource Sharing (차별화된 성능 기반을 이용한 Hybrid P2P 시스템)

  • Min, Su-Hong;Cho, Dong-Sub
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.55 no.2
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    • pp.62-64
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    • 2006
  • The emerging peer-to-peer (P2P) model has recently gained a significant attention due to its high potential of sharing various resources among networked users. Super-peer based unstructured P2P systems have been found very effective by dividing the peers into two layers, super-peer and ordinary-peer Super-peers deal with all queries instead of ordinary-peers. The existing P2P systems assume all super-peers have equal responsibility and capabilities even if all super-peers have relative advantages and disadvantages. In this paper, we suggest the ISP2P (Intelligent Super-peer based P2P) which allows to select the best super peer to ordinary-peers. We classify super peers according as the capacity of an ordinary-peer a super-peer. We show that these considerations could improve the performance of the response time and Provide higher quality results to all peers in the network.

Design of a Security Manager in Global Peer-to-Peer Engine Based on XML (XML 기반 글로벌 Peer-to-Peer 엔진의 보안 관리자 설계)

  • 이일수;이재욱;권태숙;이승룡
    • Proceedings of the Korean Information Science Society Conference
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    • 2001.10a
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    • pp.673-675
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    • 2001
  • 본 논문에서는 PC, 웹, 모바일 환경을 지원하는 글로벌 Peer-to-Peer 엔진에서 인증, 기밀성 및 무결성을 제공하기 위해 암호화/복호화에 필요한 공개키 쌍의 생성/분배/관리 기능을 지원하는 보안 관리자의 설계에 대하여 기술한다. 기존의 Peer-to-Peer 시스템이 단지 인증기관이 발행한 인증서에 의한 공개키의 분배를 지원하는데 비해 제안된 보안 관리자는 인증서뿐만 아니라 인증서가 아닌 다른 전송매체에 의해 분배된 공개키 또한 저장/관리할 수 있는 기능을 제공한다. 이것은 기존의 시스템이 인증서를 발급 받기 위해서 복잡하고 번거로운 신원 확인과 사용료를 부담하는 것에 비해 간편하게 키를 공유하여 보안을 적용시킬 수 있다. 이를 위해 본 논문에서는 키링(Key Rings)이라는 개념을 도입하는데 이는 각 피어에 해당하는 다수의 공개키/개인키를 저장 및 관리란 수 있는 한 쌍의 자료구조로써 제공된다. 또한 본 논문은 이렇게 저장/관리되는 다수의 공개키를 선택하여 사용하기 위한 알고리즘을 제시한다. 제안된 키 링을 사용하는 방식은 인증서를 사용하는 클라이언트/서버 형태의 Peer-to-Peer 보다 순수한 Peer-to-Peer 모델에 근접한 형태라고 볼 수 있다.

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The Impact of Servicescape on Customer Experience Quality through Employee-to-customer Interaction Quality and Peer-to-peer Interaction Quality in Hedonic Service Settings

  • Choi, Beomjoon;Kim, Hyun Sik
    • Asia Marketing Journal
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    • v.17 no.2
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    • pp.73-96
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    • 2015
  • This paper investigates how servicescape perception influences customer experience quality in hedonic service settings. In addition to the direct effect of servicescape quality on customer experience quality, the indirect effects of servicescape quality on customer experience quality via employee-to-customer interaction quality and peer-to-peer interaction quality are also investigated. We collected data through a self-administered survey. The proposed relationships were tested using structural equation modeling. The results show that servicescape quality influences customer experience quality both directly and indirectly through employee-to-customer interaction quality and peer-to-peer interaction quality, and customer experience quality influences customer loyalty. Additionally, we find that the indirect path via peer-to-peer interaction quality is significant only in a low-satisfaction customer group. The indirect effect of servicescape quality perception through peer-to-peer interaction quality is significant only in low-satisfaction customer groups. Therefore, if evaluations for this indirect effect fall below an acceptable level, it should be addressed first before improving on other attributes. However, after this point, further improvements offer few if any gains; therefore, service firms should allocate their resources to quality improvements to other factors. This study is the first to investigate the indirect effects of servicescape quality on customer experience quality via peer-to-peer interaction quality in hedonic service settings. Additionally, this study demonstrates that the significance of this indirect effect applies only to a low-satisfaction customer group.

An Efficient Peer-to-Peer Based Replication Strategy for Data Grid (데이터 그리드를 위한 효율적인 Peer-to-Peer 기반 복제 정책)

  • Oh, Sang-Won;Lee, Won-Joo;Jeon, Chang-Ho
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.45 no.2
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    • pp.10-17
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    • 2008
  • In this paper, we propose an efficient data replication strategy based on Peer-to-Peer which improves the performance of Data Grid system. The key idea of this replication strategy is to add the Peer-to-Peer concept for reducing data transmission restriction caused by hierarchical topology. And, it makes the nodes can store data replica to set a critical section at the storage of client level nodes. Therefore, it is possible to transmit the data replica between client level nodes and from client level nodes to upper data replication server. It is more effective to transmit data replica between client level nodes than transmitting data replica 1mm data server or data replication server with respect to minimize the transmission time. This results in improving the performance of Data Grid system. Through simulation, we show that the proposed data replication strategy based on Peer-to-Peer improves the performance of entire Data Grid environment compared to previous strategies.

Experience in Using Peer-to-Peer Platforms and Immersive Technologies in the Training of Future Masters of Pharmacy in Medical Lyceum

  • Volodymyrovych, Tsekhmister Yaroslav;Tetiana, Konovalova;Yaroslavovych, Tsekhmister Bogdan
    • International Journal of Computer Science & Network Security
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    • v.22 no.2
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    • pp.23-28
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    • 2022
  • The present study has been conducted to evaluate the experience in using peer-to-peer platforms and immersive technologies in the training of future masters of pharmacy from the Pharmaceutical Faculty of Bogomolets National Medical University, Ukraine. The selected participants were given the pre- and post-test containing multiple choice questions to assess the effectiveness of immersive technologies. Further, a self-designed structured questionnaire contained 10 questions with 5 options was delivered to consented participants through email and WhatsApp. The results of test presented that students attained an average of 26% in their pre-test while the average attained score post-test was 74% that showed a significant improvement with peer-to-peer platforms and virtual reality technology. The results of survey questions also showed an overall 86.73% satisfaction for the use of peer-to-peer platforms and virtual reality technology in the training of future masters of pharmacy. These results demonstrated that 90.81% showed agreement that they gained a high level of confidence through peer-to-peer platforms and virtual reality to handle patients in clinical practice. It can be concluded that participants of this study showed a strong agreement with positive experience in using peer-to-peer platforms and virtual reality technology in the training of future masters of pharmacy in medical lyceum.

Peer-to-Peer System using Super Peers for Mobile Environments (모바일 환경에서 슈퍼 피어를 이용한 피어-투-피어 시스템)

  • Han, Jung-Suk;Song, Jin-Woo;Lee, Kwang-Jo;Yang, Sung-Bong
    • Journal of KIISE:Computing Practices and Letters
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    • v.14 no.3
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    • pp.286-290
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    • 2008
  • As the number of mobile device users increases, many researches on peer-to-peer(P2P) systems in mobile environments have been carried out. In this paper, we propose a couple of double-layered P2P file sharing systems to overcome the 'flooding' problem in previous mobile P2P systems. We classify peers into two groups, super peers and sub-peers to establish new routing tables. A super peer manages its sub-peers in the systems. The first proposed system partitions the service area into small cells, each of which is a square. Each super peer is located near the center of the square. The second system selects super peers which have the largest number of adjacent peers. As file transmission and file searches are managed mainly by super peers, unnecessary multi-broadcasting could be avoided. The experimental results show that the proposed systems outperform a typical file sharing system in terms of the amount of message traffic with about $1.2{\sim}1.6$ times improvement on the average.