• Title/Summary/Keyword: fully distributed

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A Workqueue Replication Scheduling Algorithm Using Static Information on Grid Systems (그리드 시스템에서 정적정보를 활용한 작업큐 중복 스케줄링 알고리즘)

  • Kang, Oh-Han;Kang, Sang-Sung;Song, Hee-Heon
    • The KIPS Transactions:PartA
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    • v.16A no.1
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    • pp.9-16
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    • 2009
  • Because Grid system consists of heterogenous computing resources, which are distributed on a wide scale, it is impossible to efficiently execute applications with scheduling algorithms of a conventional parallel system that, in contrast, aim at homogeneous and controllable resources. To suggest an algorithm that can fully reflect the characteristics of a grid system, our research is focused on examining the type of information used in current scheduling algorithms and consequently, deriving factors that could develop algorithms further. The results from the analysis of these algorithms not only show that static information of resources such as capacity or the number of processors can facilitate the scheduling algorithms but also verified a decrease in efficiency in case of utilizing real time load information of resources due to the intrinsic characteristics of a grid system relatively long computing time, and the need for the means to evade unfeasible resources or ones with slow processing time. In this paper, we propose a new algorithm, which is revised to reflect static information in the logic of WQR(Workqueue Replication) algorithms and show that it provides better performance than the one used in the existing method through simulation.

Proposals for New Regulations Concerning Consumer ADR and ODR and their Implications in the EU (EU의 소비자 ADR 및 ODR에 관한 새로운 규정 논의와 국내에의 시사점)

  • Son, Hyun
    • Journal of Arbitration Studies
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    • v.23 no.1
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    • pp.107-131
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    • 2013
  • Online-ADR (Alternative Dispute Resolution) has been receiving attention from the international community as a means of alternative dispute resolution for consumer disputes in both small and mass international e-commerce. The EU Parliament and the Council proposed the Online Dispute Resolution Regulation for Consumer Disputes (hereafter, "EU Consumer ODR Regulation") and the Directive on Alternative Dispute Resolution of Consumer Disputes (hereafter, "EU Consumer ADR Directive") as a legislative package, now scheduled to be adopted. Those efforts strengthen consumer protection by enhancing ODR in international e-commerce and improving of the functions of the e-commerce market. The EU Consumer ADR and ODR regulation package will operate in conjunction with the ODR platform as a single point across Europe, abandoning the ADR system of each member. Consumers and traders who need dispute resolution apply on the EU ODR platform linked website, and the applications are distributed to individual ADR institutions in accordance with the Rules and Procedure of ADR institutions in the respective country. Although there has been partial progress in Korea for ODR programs such as the establishment of the Online Administrative Trial and the procedures of individual ADR agencies operating through the website, existing norms do not fully support the system. At this point, we see many implications of the EU Consumer ADR and ODR regulation package on the direction chosen for domestic ADR and ODR policy and legislation. This study introduces the main features and content of the EU Consumer ADR Directive (draft) and ODR Regulation provisions, and describes the direction of domestic policy and legislation regarding Online-ADR.

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Crystallographic Analysis of Ar Encapsulate within Cs3-A Zeolite

  • Lim, Woo Taik;Kim, Bok Jo;Park, Jong Sam;Chang, Chang Hwan;Jung, Sung Wook;Heo, Nam Ho
    • Analytical Science and Technology
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    • v.15 no.6
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    • pp.540-549
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    • 2002
  • The arrangement of encapsulated Ar atoms in the molecular-dimensioned cavities of fully dehydrated zeolite A of unit-cell composition $Cs_3Na_8HSi_{12}Al_{12}O_{48}$ ($Cs_3$-A) has been studied crystallographically to probe the confinement effect of guest species in microporous environment. Atoms of Ar were encapsulated in the cavities of $Cs_3$-A by treatment with 410 atm of Ar at $400^{\circ}C$ for two days, followed by cooling at room temperature. The crystal structure of $Cs_3Na_8H$-A(4Ar) ($P_e$ = 410 atm, $a=12.245(2){\AA}$, $R_1=0.0543$, and $R_2=0.0552$) has been determined by single crystal X-ray diffraction technique in the cubic space group $Pm\bar{3}m$ at 21 (1) $^{\circ}C$ and 1 atm. Encapsulated Ar atoms are distributed in three crystallographic distinct positions: 1.5 Ar atoms per unit cell opposite 6-rings, 1.5 opposite four-rings in the large cavity, and finally 1.0 in the sodalite-unit. The possible structures of argon clusters, such as $Ar_2$, $Ar_3$, and $Ar_4$, are proposed.

A Study on the Effect of the Name Node and Data Node on the Big Data Processing Performance in a Hadoop Cluster (Hadoop 클러스터에서 네임 노드와 데이터 노드가 빅 데이터처리 성능에 미치는 영향에 관한 연구)

  • Lee, Younghun;Kim, Yongil
    • Smart Media Journal
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    • v.6 no.3
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    • pp.68-74
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    • 2017
  • Big data processing processes various types of data such as files, images, and video to solve problems and provide insightful useful information. Currently, various platforms are used for big data processing, but many organizations and enterprises are using Hadoop for big data processing due to the simplicity, productivity, scalability, and fault tolerance of Hadoop. In addition, Hadoop can build clusters on various hardware platforms and handle big data by dividing into a name node (master) and a data node (slave). In this paper, we use a fully distributed mode used by actual institutions and companies as an operation mode. We have constructed a Hadoop cluster using a low-power and low-cost single board for smooth experiment. The performance analysis of Name node is compared through the same data processing using single board and laptop as name nodes. Analysis of influence by number of data nodes increases the number of data nodes by two times from the number of existing clusters. The effect of the above experiment was analyzed.

Data-Driven Signal Decomposition using Improved Ensemble EMD Method (개선된 앙상블 EMD 방법을 이용한 데이터 기반 신호 분해)

  • Lee, Geum-Boon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.2
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    • pp.279-286
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    • 2015
  • EMD is a fully data-driven signal processing method without using any predetermined basis function and requiring any user parameters setting. However EMD experiences a problem of mode mixing which interferes with decomposing the signal into similar oscillations within a mode. To overcome the problem, EEMD method was introduced. The algorithm performs the EMD method over an ensemble of the signal added independent identically distributed white noise of the same standard deviation. Even so EEMD created problems when the decomposition is complete. The ensemble of different signal with added noise may produce different number of modes and the reconstructed signal includes residual noise. This paper propose an modified EEMD method to overcome mode mixing of EMD, to provide an exact reconstruction of the original signal, and to separate modes with lower cost than EEMD's. The experimental results show that the proposed method provides a better separation of the modes with less number of sifting iterations, costs 20.87% for a complete decomposition of the signal and demonstrates superior performance in the signal reconstruction, compared with EEMD.

Effects of Zr-hydride distribution of irradiated Zircaloy-2 cladding in RIA-simulating pellet-clad mechanical interaction testing

  • Magnusson, Per;Alvarez-Holston, Anna-Maria;Ammon, Katja;Ledergerber, Guido;Nilsson, Marcus;Schrire, David;Nissen, Klaus;Wright, Jonathan
    • Nuclear Engineering and Technology
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    • v.50 no.2
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    • pp.246-252
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    • 2018
  • A series of simulated reactivity-initiated accident (RIA) tests on irradiated fully recrystallized boiling water reactor Zircaloy-2 cladding has been performed by means of the expansion-due-to-compression (EDC) test method. The EDC method reproduces fuel pellet-clad mechanical interaction (PCMI) conditions for the cladding during RIA transients with respect to temperature and loading rates by out-of-pile mechanical testing. The tested materials had a large variation in burnup and hydrogen content (up to 907 wppm). The results of the EDC tests showed variation in the PCMI resistance of claddings with similar burnup and hydrogen content, making it difficult to clearly identify ductile-to-brittle transition temperatures. The EDC-tested samples of the present and previous work were investigated by light optical and scanning electron microscopy to study the influence of factors such as azimuthal variation of the Zr-hydrides and the presence of hydride rims and radially oriented hydrides. Two main characteristics were identified in samples with low ductility with respect to hydrogen content and test temperature: hydride rims and radial hydrides at the cladding outer surface. Crack propagation and failure modes were also studied, showing two general modes of crack propagation depending on distribution and amount of radially oriented hydrides. It was concluded that the PCMI resistance of irradiated cladding under normal conditions with homogenously distributed circumferential hydrides is high, with good margin to the RIA failure limits. To further improve safety, focus should be on conditions causing nonfavorable hydride distribution, such as hydride reorientation and formation of hydride blisters at the cladding outer surface.

A Method for Minimizing the Number of Clusters in Ad-Hoc Networks (Ad-Hoc 네트워크에서 클러스터 수를 최소화하기 위한 방안)

  • Bang Sang-Won
    • Journal of Internet Computing and Services
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    • v.5 no.6
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    • pp.21-30
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    • 2004
  • In Ad-Hoc network, the cluster structure enables effective use of multiple channels, reduces the number of control messages, and increase the scalability of network, Also, it is employed for reducing the number of broadcast messages in an Ad-Hoc network. With the consideration of these advantages, it is desirable that a cluster structure keeps a few clusters in the network, Generally, the cluster formation scheme based on connectivity yields fewer clusters than the other schemes. However, the connectivity based scheme may yield even more clusters than the other schemes according to the network topology. In this paper, a cluster formation scheme dividing the cluster formation into two phases is proposed. In the first phase, the lowest connectivity host in neighborhood initiates the cluster formation. Then, an adjustment procedure for affiliating a lot of the lowest connectivity hosts is employed. In the second phase, the hosts which were not affiliated to the first phase clusters are grouped into one or more clusters through criterions of connectivity and host ID. As a result, the proposed scheme yields a fewer clusters compared with existing other schemes in fully distributed method. The simulation results proves that our scheme is better than LIDCP(3) and HCCP(3).

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Development of Integrated Retrieval System of the Biology Sequence Database Using Web Service (웹 서비스를 이용한 바이오 서열 정보 데이터베이스 및 통합 검색 시스템 개발)

  • Lee, Su-Jung;Yong, Hwan-Seung
    • The KIPS Transactions:PartD
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    • v.11D no.4
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    • pp.755-764
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    • 2004
  • Recently, the rapid development of biotechnology brings the explosion of biological data and biological data host. Moreover, these data are highly distributed and heterogeneous, reflecting the distribution and heterogeneity of the Molecular Biology research community. As a consequence, the integration and interoperability of molecular biology databases are issue of considerable importance. But, up to now, most of the integrated systems such as link based system, data warehouse based system have many problems which are keeping the data up to date when the schema and data of the data source are changed. For this reason, the integrated system using web service technology that allow biological data to be fully exploited have been proposed. In this paper, we built the integrated system if the bio sequence information bated on the web service technology. The developed system allows users to get data with many format such as BSML, GenBank, Fasta to traverse disparate data resources. Also, it has better retrieval performance because the retrieval modules of the external database proceed in parallel.

Fuzzy Modelling and Fuzzy Controller Design with Step Input Responses and GA for Nonlinear Systems (비선형 시스템의 계단 입력 응답과 GA를 이용한 퍼지 모델링과 퍼지 제어기 설계)

  • Lee, Wonchang;Kang, Geuntaek
    • Journal of the Korean Institute of Intelligent Systems
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    • v.27 no.1
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    • pp.50-58
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    • 2017
  • For nonlinear control system design, there are many studies based on TSK fuzzy model. However, TSK fuzzy modelling needs nonlinear dynamic equations of the object system or a data set fully distributed in input-output space. This paper proposes an modelling technique using only step input response data. The technique uses also the genetic algorithm. The object systems in this paper are nonlinear to control input variable or output variable. In the case of nonlinear to control input, response data obtained with several step input values are used. In the case of nonlinear to output, step input response data and zero input response data are used. This paper also presents a fuzzy controller design technique from TSK fuzzy model. The effectiveness of the proposed techniques is verified with numerical examples.

Proposal for a Peer Decentralized Identity System Using Short-Range Wireless Communications (단거리 무선 통신을 이용한 개인 간 분산 신원증명 시스템 제안)

  • Yeo, Kiho;Park, Keundug;Youm, Heung Youl
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.31 no.5
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    • pp.959-972
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    • 2021
  • Decentralized Identity is based on the concept of self-sovereign identity, in which holders manage and provide their own credentials. However, a procedure is required to obtain credentials from issuers, and there is a risk of mess personal information leaking due to negligence of the issuers. In this paper, we propose a peer decentralized identity system based on Peer DID technology that allows only participants to verify their identity in 1:1 or 1:N small groups by matching the holder with the issuer. It is directly connected to a mobile device using short-range wireless communications such as bluetooth, and the holders create and provide their own credentials in person to the other party, thus fully realizing the self-sovereignty identity. The proposed system can simplify the identification process, improve security and privacy, and reduce costs. Furthermore, an extended architecture is possible to connect the proposed system and the distributed ledger to identify users in other domains. In the future, based on various technologies, it is also necessary to expand research on identity systems that can be utilized for human-to-thing and things-to-things authentication.