• Title/Summary/Keyword: P2P networks

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Design and Implementation of a Efficient Storage Virtualization System based on Distributed Hash Tables (분산 해시 테이블 기반의 효율적인 저장 장치 가상화 시스템의 설계 및 구현)

  • Kim, Jong-Hyeon;Lee, Sang-Jun
    • Journal of Internet Computing and Services
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    • v.10 no.3
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    • pp.103-112
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    • 2009
  • This paper proposes an efficient storage virtualization system which allows users to view hard disk resources of numerous nodes as a large logical space using distributed hash tables of P2P techniques. The proposed system is developed at device level of Windows operating system and is suitable for users in Intranet environments. This system is developed to be recognized as one hard disk at the Windows explorer for user conveniences and does not need a supplementary client program at the application layer. In addition, it enhances security via cutting off breaches from external networks.

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Efficient Multicast Transmission Scheme in WiMedia D-MAC for Seamless N-Screen Services (Seamless N-스크린 서비스를 위한 WiMedia D-MAC에서의 효율적인 멀티캐스트 전송 기술)

  • Hur, Kyeong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.4
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    • pp.813-818
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    • 2015
  • In this paper, WiMedia Distributed-MAC protocol is adopted for development of a seamless N-screen wireless service. Furthermore, to provide the OSMU (One Source Multi Use) N-screen service through P2P streaming in the seamless D-MAC protocol, a new Multicast-free DRP Availability IE is proposed and analyzed. In this Multicast-free DRP Availability IE, indicating Multicast DRP Owner and Receiver is required. The ACK frame transmissions are not required for Multicast transmissions in P2P N-screen services. Using this property, the Multicast-free DRP Availability IE scheme is proposed to expand the number of time slots available for unicast and multicast DRP reservations. Simulation results show that our Multicast scheme enhances performances in vewpoints of DRP reservation conflict and throughput.

A Study on Share Group Configuration Technique for Improving Data Transmission Performance (데이터 전달 성능 향상을 위한 공유 그룹 구성 기법에 관한 연구)

  • Yang, Hwanseok
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.11 no.1
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    • pp.89-96
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    • 2015
  • The various services applied internet have been provided by the rapid development of wireless networks and providing multimedia contents are also increasing. It is caused a number of problems such as increasing of network traffic rapidly. P2P technique is gaining popularity for solving these problems. In particular, P2P technique in a wireless network environment has gained much popularity. Among them, MANET-based P2P techniques has been studied actively. It is not easy to be applied the existing technique as it is due to the dynamic topology and low bandwidth by moving nodes in MANET that is consisted of only mobile nodes. In this paper, we proposed sharing group construction technique for providing a stable connection between mobile nodes and reducing the load of network traffic and overhead of sharing group reconfiguration in order to improve data transmission performance between mobile nodes. The sharing group member nodes applied virtual sharing group generation technique with neighboring nodes of 1-hop distance in order to reduce traffic for file sharing. We performed comparative experiments with DHT technique to evaluate the performance of the proposed technique in this paper and the excellent performance is confirmed through experiments.

Preparation and Characterization of pH-Sensitive Poly(ethylene oxide) Grafted Methacrylic Acid and Acrylic Acid Hydrogels by ${\gamma}-ray $ Irradiation

  • Lim, Youn-Mook;Lee, Young-Moo;Nho, Young-Chang
    • Macromolecular Research
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    • v.13 no.4
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    • pp.327-333
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    • 2005
  • pH-sensitive hydrogels were studied as a drug carrier for the protection of insulin from the acidic environment of the stomach before releasing it in the small intestine. In this study, hydrogels based on poly(ethylene oxide) (PEO) networks grafted with methacrylic acid (MAA) or acrylic acid (AAc) were prepared via a two-step process. PEO hydrogels were prepared by ${\gamma}-ray $ irradiation (radiation dose: 50 kGy, dose rate: 7.66 kGy/h), grafted by either MAA or AAc monomers onto the PEO hydrogels and finally underwent irradiation (radiation dose: 520 kGy, dose rate: 2.15 kGy/h). These grafted hydrogels showed a pH-sensitive swelling behavior. The grafted hydrogels were used as a carrier for the drug delivery systems for the controlled release of insulin. Drug-loaded hydrogels were placed in simulated gastric fluid (SGF, pH 1.2) for 2 hr and then in simulated intestinal fluid (SIF, pH 6.8). The in vitro drug release behaviors of these hydrogels were examined by quantification analysis with a UV-Vis spectrophotometer.

Coreference Resolution for Korean Pronouns using Pointer Networks (포인터 네트워크를 이용한 한국어 대명사 상호참조해결)

  • Park, Cheoneum;Lee, Changki
    • Journal of KIISE
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    • v.44 no.5
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    • pp.496-502
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    • 2017
  • Pointer Networks is a deep-learning model for the attention-mechanism outputting of a list of elements that corresponds to the input sequence and is based on a recurrent neural network (RNN). The coreference resolution for pronouns is the natural language processing (NLP) task that defines a single entity to find the antecedents that correspond to the pronouns in a document. In this paper, a pronoun coreference-resolution method that finds the relation between the antecedents and the pronouns using the Pointer Networks is proposed; furthermore, the input methods of the Pointer Networks-that is, the chaining order between the words in an entity-are proposed. From among the methods that are proposed in this paper, the chaining order Coref2 showed the best performance with an F1 of MUC 81.40 %. The method showed performances that are 31.00 % and 19.28 % better than the rule-based (50.40 %) and statistics-based (62.12 %) coreference resolution systems, respectively, for the Korean pronouns.

A Non-parametric Trend Analysis of Water Quality Using Water Environment Network Data in Nakdong River (낙동강수계 물환경측정망 자료를 이용한 비모수적 수질 경향 비교 및 분석)

  • Kim, Jungmin;Jeong, Hyungi;Kim, Hyeran;Kim, Yongseok;Yang, Deukseok
    • Journal of Environmental Impact Assessment
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    • v.29 no.1
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    • pp.61-77
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    • 2020
  • In South Korea, major public waters have been systematic management under national level. Water environment network has been continuous monitoring for change of aquatic ecosystem, river and reservoir. In Water Quality Monitoring Networks, the data have been generally monitored Per eight days or month, while in Automatic Water Quality Monitoring Network the data have been monitored at daily intervals. Therefore, we were compared and analyzed water quality data between the networks using statistic method for same water quality item. Mann-kendall test results confirm that all points in Water Temperature (WT) and DO were not statistically significant. In particular, the result revealed that there is significant variation of TOC in the four different sites, TN in two different sites, TP in three different sites, WT in seven different sites, pH in two different sites between Water Quality Monitoring Network and Automatic Water Quality Monitoring Network. As a result firm LOWESS, TOC and pH clearly shows different trend. Among different sites, the water quality show the significantly positive correlations between at Sinam-Sangju2 and Namgang-Namgang4. Negative correlation significantly appeared in TP (ADD_Lower-AD1 site), TOC (DG-SG site), pH (GR-GR site), TP (JP-CN) and TN, TP, pH, EC, DO (GC-GC2-1 site).

DiffServ QoS Support in DSL Broadband Access Networks (DSL 광대역 접속망에서 DiffServ QoS 지원 방안)

  • Park, Seung-Chul
    • The KIPS Transactions:PartC
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    • v.13C no.5 s.108
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    • pp.613-620
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    • 2006
  • From both techlical and economic viewpoints, DiffServ IP QoS architecture is accepted as a more practical solution because of the complexity Problem of the other IntServ architecture. In this paper, we propose several models to support DiffServ QoS in DSL broadband access networks and discuss about migration path from current best-effort DSL networks to DiffServ-enabled ones. Since DSL networks are recently and widely deployed in the world amount ot new investment, compatibility with existing QoS-unaware DSL systems, and compatibility with existing charging systems as well as effective support of various QoS services must be carefully considered when we design DiffServ QoS support models in DSL networks. The DiffServ models proposed in this paper are divided into static DiffServ models and dynamic DiffServ models which are near-term solutions and long-term solutions repecitively. The static DiffServ models include Flat DiffServ which suworts per-subscriber DiffServ QoS and Structured DiffServ which supports per-subscriber and per-service DiffServ QoS. And the dynamic DiffServ models include Direct DiffServ for P2P(Peer to Peer) applications and Indirect DiffServ for ASP(Application Service Provider) applications.

A Study on the Protection Switching Mechanism for Distribution Automation System Ethernet Networks Service of Distribution Automation System (배전자동화시스템 통신서비스를 위한 이중화 통신망 보호절체 알고리즘 연구)

  • Yu, Nam-Cheol;Kim, Jae-Dong;Oh, Chae-Gon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.6
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    • pp.744-749
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    • 2013
  • The protection switching technology is widely adopted in the fiber-optical transmission equipments based on TDM(Time Division Multiplexing), such as PDH, SDH/SONET. A variety of protection switching algorithms for Ethernet networks and the progress of standardization are summarized in the document. There are several kinds of protection switching algorithms for Ethernet networks, such as STP, RSTP, MSTP and etc. However, since Ethernet signal move through detour route, it causes much time to recover. Accordingly, it is difficult to secure a usability of Ethernet networks and QOS(Quality of Service). Also, if the protection switching protocol standardized by IEEE and ITU-T is used, it remains a inherent network switching time for protection. Therefore, a specific protection switching algorithm for Ethernet are needed for seamless and stable operation of Ethernet networks service for Distribution Automation System(DAS). A reliable protection algorithm with no switching delay time is very important to implement Self-healing service for DAS. This study of FPGA based protection switching algorithm for Ethernet networks shows that in case of faults occurrence on distribution power network, immediate fault isolation and restoration are conducted through interaction with distribution equipments using P2P(Peer to Peer) communication for protection coordination. It is concluded that FPGA based protection switching algorithm for Ethernet networks available 0ms switching time is crucial technology to secure reliability of DAS.

Continuous K-Nearest Neighbor Query Processing Considering Peer Mobilities in Mobile P2P Networks (모바일 P2P 네트워크에서 피어의 이동성을 고려한 연속적인 k-최근접 질의 처리)

  • Bok, Kyoung-Soo;Lee, Hyun-Jung;Park, Young-Hun;Yoo, Jae-Soo
    • The Journal of the Korea Contents Association
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    • v.12 no.8
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    • pp.47-58
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    • 2012
  • In this paper, we propose a continuous k-nearest neighborhood query processing method for updating the query results in real-time over mobile peer-to-peer environments. The proposed method disseminates a monitoring region to efficiently monitor the k-nearest neighbor peers. The Monitoring Region is created to assure at least k peers as the result of the query within the time range using the vector of neighbor peers. In the propose method, the monitoring region is valid for a long time because it is calculated by the vector of neighbor peers of the query peer. Therefore, the proposed method decreases the cost of re-processing by monitoring region invalidation. In order to show the superiority of the proposed method, we compare it with the previous schemes through performance evaluation.

Korean Hedge Detection Using Word Usage Information and Neural Networks (단어 쓰임새 정보와 신경망을 활용한 한국어 Hedge 인식)

  • Ren, Mei-Ying;Kang, Sin-jae
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.7 no.9
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    • pp.317-325
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    • 2017
  • In this paper, we try to classify Korean hedge sentences, which are regarded as not important since they express uncertainties or personal assumptions. Through previous researches to English language, we found dependency information of words has been one of important features in hedge classification, but not used in Korean researches. Additionally, we found that word embedding vectors include the word usage information. We assume that the word usage information could somehow represent the dependency information. Therefore, we utilized word embedding and neural networks in hedge sentence classification. We used more than one and half million sentences as word embedding dataset and also manually constructed 12,517-sentence hedge classification dataset obtained from online news. We used SVM and CRF as our baseline systems and the proposed system outperformed SVM by 7.2%p and also CRF by 1.2%p. This indicates that word usage information has positive impacts on Korean hedge classification.