• Title/Summary/Keyword: web node

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A Study on the Web Service Migration Based on Websocket (웹소켓을 활용한 웹 서비스 이동 연구)

  • Choi, Hun-Hoi;Kim, Geun-Hyung
    • Annual Conference of KIPS
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    • 2011.04a
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    • pp.1151-1153
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    • 2011
  • 본 논문은 Node.js 와 HTML5 의 웹소켓(Websocket)을 활용하여 사용자가 브라우저를 통해 이용중인 웹 서비스의 콘텐츠를 다른 단말로 이동하는 구조와 알고리즘을 서술한다. 제안된 구조와 알고리즘을 통해 다양한 플랫폼과 단말 간 서비스가 이동됨을 알 수 있다. 기존의 폴링(Polling)방식을 사용한 웹 서비스 이동과 본 논문에서 제시한 알고리즘의 실험 결과를 통해 제시한 알고리즘의 성능이 우수함을 보였다. 사용자 단말의 트래픽은 5~13 배 가량 줄었으며, 응답 시간은 폴링방식에 비해 빠른 응답시간을 나타냈다. 실험에서는 자바스크립트를 사용하여 확장성이 높은 Node.js와 HTML5 의 새로운 표준인 웹소켓을 활용하였으며, 제시한 구조와 알고리즘이 앞으로 웹 서비스 이동 시 다양한 단말 간 서비스 이동에 효과적으로 전달될 수 있음을 보였다.

Main Memory Spatial Database Clusters for Large Scale Web Geographic Information Systems (대규모 웹 지리정보시스템을 위한 메모리 상주 공간 데이터베이스 클러스터)

  • Lee, Jae-Dong
    • Journal of Korea Spatial Information System Society
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    • v.6 no.1 s.11
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    • pp.3-17
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    • 2004
  • With the rapid growth of the Internet geographic information services through the WWW such as a location-based service and so on. Web GISs (Geographic Information Systems) have also come to be a cluster-based architecture like most other information systems. That is, in order to guarntee high quality of geographic information service without regard to the rapid growth of the number of users, web GISs need cluster-based architecture that will be cost-effective and have high availability and scalability. This paper proposes the design of the cluster-based web GIS with high availability and scalability. For this, each node within a cluster-based web GIS consists of main memory spatial databases which accomplish role of caching by using data declustering and the locality of spatial query. Not only simple region queries but also the proposed system processed spatial join queries effectively. Compare to the existing method. Parallel R-tree spatial join for a shared-Nothing architecture, the result of simulation experiments represents that the proposed spatial join method achieves improvement of performance respectively 23% and 30% as data quantity and nodes of cluster become large.

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VOD Server using Web-Caching in Head-End-Network (Head-End-Network에서 Web-Caching을 사용한 VOD 서버)

  • Kim Backhyun;Hwang Taejune;Kim Iksoo
    • Journal of Internet Computing and Services
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    • v.5 no.1
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    • pp.15-23
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    • 2004
  • This paper presents distributive web-caching technique on the Head-End-Network (HNET) to solve excessive load of multimedia sever and inefficient use of network resources, The proposed web-caching is not concentration of load for a specific Head-End-Node(HEN), and it has advantage that there is no copy of a specific item on distributive HENs. This technique distributively stores on HENs partial streams of requested videos from clients connected to HENs and the order of store streams follows the order of request of identical video items from HENs. Thus, storing streams on each HEN that requests sevice are different. When a client requests the cached video on some HENs, the HEN that connects him receives streams in the order of store from HENs which stored them and it transmits them to him. These procedures are performed under the control of SA. This technique uses cache replacement algorithm that the combination of LFU, LRU and the last remove for the first stream of videos In order to reduce end-to-end delay.

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OPNFV Promise Project (OPNFV Promise 프로젝트)

  • Baek, D.M.;Lee, B.C.
    • Electronics and Telecommunications Trends
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    • v.31 no.6
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    • pp.67-76
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    • 2016
  • Promise는 OPNFV의 자원 예약 및 할당, 용량 관리 프로젝트이다. 자원을 많이 필요로 하는 월드컵 경기나 쓰나미 경보 같은 재해를 대비한 자원 예약을 통해 끊임없는 서비스를 제공하기 위함이다. 그러나 기능 구현을 위해 OpenStack 내 많은 컴포넌트의 수정이 필요한 어려운 점이 있다. 그래서 Phase2의 OpenStack 과의 통합된 모델을 목표로, 현재의 Phase1은 Shim-layer 구현물 단계에 있다. Shim-layer는 Node.js 위에서 실행되는 YangForge 프레임워크로 기술된다. 이는 Yang 데이터 모델링로서 스키마를 표현하고, 컨트롤 로직은 YAML로, 설정 데이타는 JSON으로, JavaScript를 만드는 CoffeeScript 언어로서 스펙을 기술한다. 인터페이스는 CLI, Web GUI, REST/JSON, WebSockets이다. 이를 OPNFV summit 2015년 11월에 데모한 바 있다. 이 프로젝트를 분석을 통해 용량 관리, 자원 예약 및 자원 할당하는 예약기법들을 살펴보고자 한다.

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A Study on Machine Learning Algorithm for Intelligent Information Retrieval in World Wide Web (WWW상의 지능형 정보검색을 위한 기계학습 알고리즘 구현에 관한 연구)

  • 김성희
    • Journal of the Korean Society for information Management
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    • v.17 no.2
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    • pp.189-205
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    • 2000
  • We investigate the appropriate design and implementation of an Inductive Learning Alogrithm with a Neural Network in order to solve both inconsistent indexing and incomplete query problems on the web. Specifically, the proposed system based queries and documents in the field of Mathematics shows how inductive learning method and neural networks can apply to information retreival. Also, this study examines all of parameters of the neural networks -- the number of node in input and output, hidden layer size and learning parameters etc. -- which are significant in determining how well the neural network will converge.

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A study on high availability of the linux clustering web server (리눅스 클러스터링 웹 서버의 고가용성에 대한 연구)

  • 박지현;이상문;홍태화;김학배
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.88-88
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    • 2000
  • As more and more critical commercial applications move on the Internet, providing highly available servers becomes increasingly important. One of the advantages of a clustered system is that it has hardware and software redundancy. High availability can be provided by detecting node or daemon failure and reconfiguring the system appropriately so that the workload can be taken over bi the remaining nodes in the cluster. This paper presents how to provide the guaranteeing high availability of clustering web server. The load balancer becomes a single failure point of the whole system. In order to prevent the failure of the load balancer, we setup a backup server using heartbeat, fake, mon, and checkpointing fault-tolerance method. For high availability of file servers in the cluster, we setup coda file system. Coda is a advanced network fault-tolerance distributed file system.

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Implementation of a Real-Time Communication Service System Using WebSocket (웹소켓을 이용한 실시간 커뮤니케이션 서비스 시스템 구현)

  • Kim, Nayoung;Shin, Dayoung;Choe, Hyejin;Shim, Junho;Lee, Ki Yong
    • Annual Conference of KIPS
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    • 2013.11a
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    • pp.553-555
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    • 2013
  • 본 논문은 HTML5의 새로운 표준인 웹소켓(WebSocket)을 이용하여 구현한 실시간 커뮤니케이션 시스템을 소개한다. 본 논문에서 구현한 시스템은 PC의 브라우저와 모바일 디바이스 모두를 통해 접근이 가능하다. 본 논문에서 구현한 실시간 커뮤니케이션 서비스 시스템은 이벤트 기반의 비동기 방식을 채택함으로써, 클라이언트가 리로드(reload)하지 않더라도 필요한 정보를 빠르게 제공한다. PC의 브라우저가 접근하는 부분은 Node.js를 사용하여 구현하였으며, 모바일 디바이스가 접근하는 부분은 PhoneGap 플랫폼을 사용하여 구현하였다. 본 논문에서는 시스템의 전체 구조와 관련 기술을 설명하고, 구체적인 구현 코드의 일부를 제시하며, 추후 확장 가능성과 비전을 제시한다.

A Ranking Algorithm for Semantic Web Resources: A Class-oriented Approach (시맨틱 웹 자원의 랭킹을 위한 알고리즘: 클래스중심 접근방법)

  • Rho, Sang-Kyu;Park, Hyun-Jung;Park, Jin-Soo
    • Asia pacific journal of information systems
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    • v.17 no.4
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    • pp.31-59
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    • 2007
  • We frequently use search engines to find relevant information in the Web but still end up with too much information. In order to solve this problem of information overload, ranking algorithms have been applied to various domains. As more information will be available in the future, effectively and efficiently ranking search results will become more critical. In this paper, we propose a ranking algorithm for the Semantic Web resources, specifically RDF resources. Traditionally, the importance of a particular Web page is estimated based on the number of key words found in the page, which is subject to manipulation. In contrast, link analysis methods such as Google's PageRank capitalize on the information which is inherent in the link structure of the Web graph. PageRank considers a certain page highly important if it is referred to by many other pages. The degree of the importance also increases if the importance of the referring pages is high. Kleinberg's algorithm is another link-structure based ranking algorithm for Web pages. Unlike PageRank, Kleinberg's algorithm utilizes two kinds of scores: the authority score and the hub score. If a page has a high authority score, it is an authority on a given topic and many pages refer to it. A page with a high hub score links to many authoritative pages. As mentioned above, the link-structure based ranking method has been playing an essential role in World Wide Web(WWW), and nowadays, many people recognize the effectiveness and efficiency of it. On the other hand, as Resource Description Framework(RDF) data model forms the foundation of the Semantic Web, any information in the Semantic Web can be expressed with RDF graph, making the ranking algorithm for RDF knowledge bases greatly important. The RDF graph consists of nodes and directional links similar to the Web graph. As a result, the link-structure based ranking method seems to be highly applicable to ranking the Semantic Web resources. However, the information space of the Semantic Web is more complex than that of WWW. For instance, WWW can be considered as one huge class, i.e., a collection of Web pages, which has only a recursive property, i.e., a 'refers to' property corresponding to the hyperlinks. However, the Semantic Web encompasses various kinds of classes and properties, and consequently, ranking methods used in WWW should be modified to reflect the complexity of the information space in the Semantic Web. Previous research addressed the ranking problem of query results retrieved from RDF knowledge bases. Mukherjea and Bamba modified Kleinberg's algorithm in order to apply their algorithm to rank the Semantic Web resources. They defined the objectivity score and the subjectivity score of a resource, which correspond to the authority score and the hub score of Kleinberg's, respectively. They concentrated on the diversity of properties and introduced property weights to control the influence of a resource on another resource depending on the characteristic of the property linking the two resources. A node with a high objectivity score becomes the object of many RDF triples, and a node with a high subjectivity score becomes the subject of many RDF triples. They developed several kinds of Semantic Web systems in order to validate their technique and showed some experimental results verifying the applicability of their method to the Semantic Web. Despite their efforts, however, there remained some limitations which they reported in their paper. First, their algorithm is useful only when a Semantic Web system represents most of the knowledge pertaining to a certain domain. In other words, the ratio of links to nodes should be high, or overall resources should be described in detail, to a certain degree for their algorithm to properly work. Second, a Tightly-Knit Community(TKC) effect, the phenomenon that pages which are less important but yet densely connected have higher scores than the ones that are more important but sparsely connected, remains as problematic. Third, a resource may have a high score, not because it is actually important, but simply because it is very common and as a consequence it has many links pointing to it. In this paper, we examine such ranking problems from a novel perspective and propose a new algorithm which can solve the problems under the previous studies. Our proposed method is based on a class-oriented approach. In contrast to the predicate-oriented approach entertained by the previous research, a user, under our approach, determines the weights of a property by comparing its relative significance to the other properties when evaluating the importance of resources in a specific class. This approach stems from the idea that most queries are supposed to find resources belonging to the same class in the Semantic Web, which consists of many heterogeneous classes in RDF Schema. This approach closely reflects the way that people, in the real world, evaluate something, and will turn out to be superior to the predicate-oriented approach for the Semantic Web. Our proposed algorithm can resolve the TKC(Tightly Knit Community) effect, and further can shed lights on other limitations posed by the previous research. In addition, we propose two ways to incorporate data-type properties which have not been employed even in the case when they have some significance on the resource importance. We designed an experiment to show the effectiveness of our proposed algorithm and the validity of ranking results, which was not tried ever in previous research. We also conducted a comprehensive mathematical analysis, which was overlooked in previous research. The mathematical analysis enabled us to simplify the calculation procedure. Finally, we summarize our experimental results and discuss further research issues.

Design of Chatting Web Application supporting a Map Share (지도 공유를 지원하는 채팅 웹 응용의 설계)

  • Lee, Han-Bin;Kim, Dong-Hyon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.05a
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    • pp.430-432
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    • 2015
  • 아웃도어는 일상공간과 자신으로부터의 탈출이라는 의미가 있다. 아웃도어 활동을 보조하는 다양한 어플리케이션이 있으며 대부분 어플리케이션은 서버에 등록된 코스를 스마트폰에 출력하고, 사람들과 대화하기위한 메신저 기능을 제공한다. 이 논문에서는 지도를 공유하며 채팅을 할 수 있는 웹 어플리케이션 설계을 제시한다.

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uPetCare : Ubiquitous Pet-Care System using Web2.0 (uPetCare : 웹2.0을 이용한 유비쿼터스 펫 케어 시스템)

  • Park, Jun-Sung;Lee, Gwi-Ro;Cho, Jin-Sung
    • Journal of KIISE:Computing Practices and Letters
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    • v.15 no.4
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    • pp.260-264
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    • 2009
  • There have been many studies on u-Healthcare system for human using sensor network systems. In this paper, we design and implement a healthcare system for pets called uPetCare(Ubiquitous Pet-Care System) that can manage the status of pet on the web. The main functions of this system are 1) gathering data using sensor network, 2) multi-hop communication in sensor network, 3) data compression and aggregation at sink node, 4) storing data in web server, 5) real-time data monitoring using AJAX, 6) activity recognition of pet.