• Title/Summary/Keyword: request-to-send

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Dynamic Source Multi-path Routing Protocol for Wireless Ad-hoc Network Environments (무선 에드-혹 네트워크 환경을 위한 동적다중경로라우팅 프로토콜)

  • Kim, Moon-Jeong;Eom, Young-Ik
    • Journal of KIISE:Information Networking
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    • v.28 no.3
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    • pp.336-346
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    • 2001
  • A wireless ad-hoc network is a temporal network formed by a collection of wireless mobile nodes without the aid of any existing network infrastnlcture or centralized administration. Currently, numerous routing protocols have been developed for changing messages between nodes in a wireless ad-hoc network. Applications of wireless ad-hoc network technology are various and proper routing protocol must be used according to application domain or network size. In a wireless ad-hoc network. some hosts want services from fixed networks. For supporting such services, it is necessary to interconnect wireless ad-hoc networks and fixed networks. The DSMIHDynamic Source Multipath Routing) protocol, proposed in this paper, focuses on supporting seamless communication services between the nodes within a wireless ad-hoc network and providing fixed networks to the mobile hosts in wireless an-hoc networks. In DSMR protocol, each node need not broadcast routing messages periodically. and mobile hosts that to send data packets initiate route request and route establishment procedure. By maintaining multiple paths in each node. faster route re-establishment is also possible in our scheme.

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Development of Network-Based Online GPS Baseline Processing System (네트워크 기반 온라인 GPS 기선해석 시스템 개발)

  • Kim, Su-Kyung;Bae, Tae-Suk
    • Journal of the Korean Association of Geographic Information Studies
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    • v.14 no.2
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    • pp.138-146
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    • 2011
  • With the increased use of GPS in the field of various applications including surveying, the request for fast and precise positional information has increased. Several countries such as USA, Canada, and Australia have already been operating Internet-based automatic GPS data analysis system using e-mail and FTP. Expanding GPS market, it is necessary to establish automatic GPS baseline processing system that is accessible via Internet. The system developed in this study is operating on the web, and it allows the users to access easily regardless of time and place. The main processing engines are Bernese V5.0 and PAGES. They process user data with three GPS CORS(Continuously Operating Reference Station), and then send the report to the users through e-mail. This system allows users to process high accurate GPS data easily. It is expected that this system will be used for various GPS applications such as monitoring large-scale structures and providing spatial information services in private sector.

Testing case analysis of Database Software (데이터베이스 소프트웨어의 시험 사례 분석)

  • Yang, Hae-Sool;Kang, Bae-Keun;Lee, Ha-Yong
    • Journal of the Korea Society of Computer and Information
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    • v.14 no.5
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    • pp.167-174
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    • 2009
  • The meaning of Database in order to manage the data which is huge in the meeting of the record which logically had become the fire tube or file 'efficiently' is widely used from the place which controls a many double meaning data. Like this data base it creates, it manages, the programs which send an answer back according to demand of the user as DBMS it calls. Like this it will be able to grasp the quality level of the data base software product which is important index from the research which index it buys it defined. Also, in order to produce the result of index it selects the collection item which is necessary and collection and analysis it leads and what kind of defect types occur substantially mainly, and it confirmed and the test and evaluation model in about data base software and a tentative instance it developed it analyzed.

An Efficient Algorithm for Constructing a Maximal Request Bandwidth Tree on Public-shared Network (공유 네트워크에서 최대 요구대역폭 트리 구축을 위한 효율적인 알고리즘)

  • Chong, Kyun-Rak
    • Journal of the Korea Society of Computer and Information
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    • v.20 no.4
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    • pp.87-93
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    • 2015
  • Recently, an idea has been suggested in which members construct the network by sharing their surplus bandwidth of their own access point. This kind of network is called public-shared network. As an application, SVC video streaming delivery system on public-shared network has been proposed. To send video stream from the stream server to clients, a tree structure is constructed where the root is a stream server, internal nodes are sharable access points, and leafs are clients. The previous researches have focused on constructing the minimal sharable-bandwidth tree which can serve all video streaming requests using the minimal sharable bandwidth. In this paper, we have shown that the problem of constructing a tree structure with given sharable access points to serve maximal video streaming requests is NP-hard. We also have developed an efficient heuristic algorithm for this problem and evaluated experimentally our algorithm.

Design and Implementation of Wet Diaper Sensor for U-Healthcare (유비쿼터스 헬스케어를 위한 대소변 감지기 설계 및 구현)

  • Yi, Yun-Jae;Kim, Tae-Suk;Park, Chul-Ho;Lim, Dong-Ha;Choi, Ik-Soo;Kim, Nam-Ho;Yu, Yun-Seop
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2011.05a
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    • pp.793-795
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    • 2011
  • In this paper, an wet diaper sensor system for u-healthcare is implemented and designed. The u-healthcare system of wet diaper sensor consists of sensor node, data-logger/gateway, and server or user terminals. The sensor node includes $NH_3$, humidity, and temperature sensors and TI CC2530 chip, and the data-logger/gateway can connect to a communication network and send the aggregated data from the sensor nodes to a server, and the server can manage the situation of the sensor node and make another analyzed information. Also user terminals can request and obtain the information necessary from the server. The algorithm for detecting wet diaper is proposed, and using the proposed algorithm, the sensitivity for detecting wet diaper is 100%.

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The International Arbitration System for the Settlement of Investor-State Disputes in the FTA (FTA(자유무역협정)에서 투자자 대 국가간 분쟁해결을 위한 국제중재제도)

  • Lee, Kang-Bin
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.38
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    • pp.181-226
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    • 2008
  • The purpose of this paper is to describe the settling procedures of the investor-state disputes in the FTA Investment Chapter, and to research on the international arbitration system for the settlement of the investor-state disputes under the ICSID Convention and UNCITRAL Arbitration Rules. The UNCTAD reports that the cumulative number of arbitration cases for the investor-state dispute settlement is 290 cases by March 2008. 182 cases of them have been brought before the ICSID, and 80 cases of them have been submitted under the UNCITRAL Arbitration Rules. The ICSID reports that the cumulative 263 cases of investor-state dispute settlement have been brought before the ICSID by March 2008. 136 cases of them have been concluded, but 127 cases of them have been pending up to now. The Chapter 11 Section B of the Korea-U.S. FTA provides for the Investor_State Dispute Settlement. Under the provisions of Section B, the claimant may submit to arbitration a claim that the respondent has breached and obligation under Section A, an investment authorization or an investment agreement and that the claimant has incurred loss or damage by reason of that breach. Provided that six months have elapsed since the events giving rise to the claim, a claimant may submit a claim referred to under the ICSID Convention and the ICSID Rules of Procedure for Arbitration Proceedings; under the ICSID Additional Facility Rules; or under the UNCITRAL Arbitration Rules. The ICSID Convention provides for the jurisdiction of the ICSID(Chapter 2), arbitration(Chapter 3), and replacement and disqualification of arbitrators(Chapter 5) as follows. The jurisdiction of the ICSID shall extend to any legal dispute arising directly out of an investment, between a Contracting State and a national of another Contracting State, which the parties to the dispute consent in writing to submit to the ICSID. Any Contracting State or any national of a Contracting State wishing to institute arbitration proceedings shall address a request to that effect in writing to the Secretary General who shall send a copy of the request to the other party. The tribunal shall consist of a sole arbitrator or any uneven number of arbitrators appointed as the parties shall agree. The tribunal shall be the judge of its own competence. The tribunal shall decide a dispute in accordance with such rules of law as may be agreed by the parties. Any arbitration proceeding shall be conducted in accordance with the provisions of the Convention Section 3 and in accordance with the Arbitration Rules in effect on the date on which the parties consented to arbitration. The award of the tribunal shall be in writing and shall be signed by members of the tribunal who voted for it. The award shall deal with every question submitted to the tribunal, and shall state the reason upon which it is based. Either party may request annulment of the award by an application in writing addressed to the Secretary General on one or more of the grounds under Article 52 of the ICSID Convention. The award shall be binding on the parties and shall not be subject to any appeal or to any other remedy except those provided for in this Convention. Each Contracting State shall recognize an award rendered pursuant to this convention as binding and enforce the pecuniary obligations imposed by that award within its territories as if it were a final judgment of a court in that State. In conclusion, there may be some issues on the international arbitration for the settlement of the investor-state disputes: for example, abuse of litigation, lack of an appeals process, and problem of transparency. Therefore, there have been active discussions to address such issues by the ICSID and UNCITRAL up to now.

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Energy-Efficient Multipath Routing Protocol for Supporting Mobile Events in Wireless Sensor Networks (무선 센서 네트워크에서 이동 이벤트를 지원하기 위한 에너지 효율적인 멀티패스 라우팅 프로토콜)

  • Kim, Hoewon;Lee, Euisin
    • KIPS Transactions on Computer and Communication Systems
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    • v.5 no.12
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    • pp.455-462
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    • 2016
  • Wireless sensor networks have been researched to gather data about events on sensor fields from sources at sinks. Multipath routing is one of attractive approaches to reliably send data against the problem of frequent breakages on paths from sources to sinks due to node and link failures. As mobile events such as humans, animals, and vehicles are considered, sources may be continuously generated according to the movement of the mobile event. Thus, mobile events provide new challenging issue in multipath routing. However, the research on multipath routing mainly focus on both efficient multipath construction from sources to static sinks and fast multipath reconstruction against path breakages. Accordingly, the previous multipath routing protocols request each source continuously generated by a mobile event to construct individual multipath from the source to sinks. This induces the increase of multipath construction cost in the previous protocols in proportion to the number of source. Therefore, we propose efficient multipath routing protocol for supporting continuous sources generated by mobile events. In the proposed protocol, new source efficiently reconstructs its multipath by exploiting the existing multipath of previous sources. To do this, the proposed protocol selects one among three reconstruction methods: a local reconstruction, a global partial one, and a global full one. For a selection decision, we provide an analytical energy consumption cost model that calculates the summation of both the multipath reconstruction cost and the data forwarding cost. Simulation results show that the proposed protocol has better performance than the previous protocol to provide multipath routing for mobile events.

A Study on Reliable Multicast Transmission using Recovery Cluster (복구 클러스터를 이용한 신뢰성 있는 멀티캐스트 전송에 관한 연구)

  • Gu, Myeong-Mo;Kim, Bong-Gi
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.11
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    • pp.1-6
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    • 2019
  • Multicast is an efficient method for real-time transmission in many multimedia applications. It is important to recover lost packets and to manage multicast groups according to the network status in order to improve the reliability of multicast transmissions. In this paper, we propose a method that can efficiently recover lost packets in a large multicast group. In the proposed method, we create a recovery cluster (RC) using a multicast domain (MD) for recovery of lost packets. In the conventional methods, clusters send a request message for lost packets to the senders in order to recover the packets lost from many multicast applications. This increases packet delay time and overhead because of the feedback messages and retransmitted packets. In the proposed method, we improve these problems using the RC, which consists of many MDs (which have overlay multicast senders), and many cluster heads (CHs). We divide the message into blocks, and divide each block into many segments for packet recovery using the CHs. When packet loss occurs, all CHs share the segment information and recover the lost segments at the same time. Simulation results show that the proposed method could improve the packet recovery ratio by about 50% compared to the conventional methods.

High-Availability Web Server Cluster Employing Multiple Front-Ends for Small and Middle-sized Web Sites (중소형 사이트를 위한 다수의 전면 서버를 갖는 고가용성 웹 서버 클러스터)

  • Moon Jong-bae;Kim Myung-ho
    • The KIPS Transactions:PartA
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    • v.11A no.5
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    • pp.355-364
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    • 2004
  • These days, various clustering technologies have been adopted to construct web sites. High performance hardware switches have good performance, but have disadvantage of high cost for constructing small and middle-sized web sites. Now a days, many sites have been constructed with the LVS (Linux Virtual Server), which is free of charge and has good performance. Having a centralized load balancing with one front-end, the LVS causes a bottleneck when it receives all at once. In the paper, we suggest a way to remove the LVS bottleneck by providing multiple front-ends. In this architecture, all of cluster nodes act as both a front-end and a back-end. When the load of a node receiving requests is not large enough, the node responds to the client directly. When the load of a node is large enough, the node send the request to a node which is selected by a scheduling algorithm. The scheduling algorithm is discussed to balance loads between servers. While single front-end cluster raises the throughput curvedly, the multiple front-end cluster raises the throughput linearly.

Automatic gasometer reading system using selective optical character recognition (관심 문자열 인식 기술을 이용한 가스계량기 자동 검침 시스템)

  • Lee, Kyohyuk;Kim, Taeyeon;Kim, Wooju
    • Journal of Intelligence and Information Systems
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    • v.26 no.2
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    • pp.1-25
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    • 2020
  • In this paper, we suggest an application system architecture which provides accurate, fast and efficient automatic gasometer reading function. The system captures gasometer image using mobile device camera, transmits the image to a cloud server on top of private LTE network, and analyzes the image to extract character information of device ID and gas usage amount by selective optical character recognition based on deep learning technology. In general, there are many types of character in an image and optical character recognition technology extracts all character information in an image. But some applications need to ignore non-of-interest types of character and only have to focus on some specific types of characters. For an example of the application, automatic gasometer reading system only need to extract device ID and gas usage amount character information from gasometer images to send bill to users. Non-of-interest character strings, such as device type, manufacturer, manufacturing date, specification and etc., are not valuable information to the application. Thus, the application have to analyze point of interest region and specific types of characters to extract valuable information only. We adopted CNN (Convolutional Neural Network) based object detection and CRNN (Convolutional Recurrent Neural Network) technology for selective optical character recognition which only analyze point of interest region for selective character information extraction. We build up 3 neural networks for the application system. The first is a convolutional neural network which detects point of interest region of gas usage amount and device ID information character strings, the second is another convolutional neural network which transforms spatial information of point of interest region to spatial sequential feature vectors, and the third is bi-directional long short term memory network which converts spatial sequential information to character strings using time-series analysis mapping from feature vectors to character strings. In this research, point of interest character strings are device ID and gas usage amount. Device ID consists of 12 arabic character strings and gas usage amount consists of 4 ~ 5 arabic character strings. All system components are implemented in Amazon Web Service Cloud with Intel Zeon E5-2686 v4 CPU and NVidia TESLA V100 GPU. The system architecture adopts master-lave processing structure for efficient and fast parallel processing coping with about 700,000 requests per day. Mobile device captures gasometer image and transmits to master process in AWS cloud. Master process runs on Intel Zeon CPU and pushes reading request from mobile device to an input queue with FIFO (First In First Out) structure. Slave process consists of 3 types of deep neural networks which conduct character recognition process and runs on NVidia GPU module. Slave process is always polling the input queue to get recognition request. If there are some requests from master process in the input queue, slave process converts the image in the input queue to device ID character string, gas usage amount character string and position information of the strings, returns the information to output queue, and switch to idle mode to poll the input queue. Master process gets final information form the output queue and delivers the information to the mobile device. We used total 27,120 gasometer images for training, validation and testing of 3 types of deep neural network. 22,985 images were used for training and validation, 4,135 images were used for testing. We randomly splitted 22,985 images with 8:2 ratio for training and validation respectively for each training epoch. 4,135 test image were categorized into 5 types (Normal, noise, reflex, scale and slant). Normal data is clean image data, noise means image with noise signal, relfex means image with light reflection in gasometer region, scale means images with small object size due to long-distance capturing and slant means images which is not horizontally flat. Final character string recognition accuracies for device ID and gas usage amount of normal data are 0.960 and 0.864 respectively.