• Title/Summary/Keyword: message redundancy

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Toward A Reusable Knowledge Based System

  • Yoo, Young-Dong
    • The Journal of Information Systems
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    • v.3
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    • pp.71-82
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    • 1994
  • Knowledge acquisition, maintenance of knowledge base, and validation and verification of knowledge are the addressed bottlenecks of building successful knowledge based systems. Along with the increment of interesting in the knowledge based systems, the organization needs to develop a new one although it has a similar one. This causes several serious problems including knowledge redundancy and maintenance of knowledge base. This paper present three models of the reusable knowledge base which might be the solution to the above problem. Three models are : 1) multiple knowledge bases for a single AI application, 2) multiple knowledge bases for multiple AI applications, 3) a single knowledge base for multiple AI applications. A new approach to build such a reusable knowledge base in a homogeneous environment is presented. Our model combines the essential object-oriented techniques with rules in a consistent manner. Important aspects of applying object-oriented techniques to AI are discussed (inheritance, encapsulation, message passing), and some potential problems in building an AI application (decomposition technique of knowledge, search time, and heterogeneous environment) are pointed out. The models of a reusable knowledge base provide several amenities : 1) reduce the knowledge redundancy, 2) reduce the effort of maintenance of the knowledge base, 3) reuse the resource of the multiple domain knowledge bases, 4) reduce the development time.

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A Cluster-based Address Allocation Protocol in MANET Environment (MANET 환경에서 클러스터 기반 주소 할당 프로토콜)

  • Cho, Young-Bok;Lee, Sang-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.9A
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    • pp.898-904
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    • 2007
  • I must receive node discernment address for communication between node that participate to network in MANETs(Mobile Ad-hoc Networks). Address is created by node confidence or different node. I achieve address redundancy check (Duplicate Address Detection) to examine whether this address is available unique address. However, this method happens problem that MANETs' extensity drops. This paper can manage by group unit binding transfer nodes to group in MANETs. I suggest method that apply special quality of cluster that exchange subordinate decrease and mobility government official of control message are easy in address assignment protocol minimize time required in redundancy check and solves extensity problem. Method that propose in this paper shows excellent performance according to node number increase than wave and MANETConf [2] through simulation.

An Improved Message Broadcast Scheme over Wireless Sensor Networks (무선 센서 네트워크에서 효율적인 메시지 방송 기법)

  • Kim, Kwan-Woong;Kim, Byun-Gon;Bae, Sung-Hwan;Kim, Dae-Ik
    • The Journal of the Korea institute of electronic communication sciences
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    • v.5 no.6
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    • pp.588-594
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    • 2010
  • In a multi-hop wireless sensor network, broadcasting is an elementary operation to support command message sending, route discovery and other application tasks. Broadcasting by flooding may cause serious redundancy, contention, and collision in the network, which is referred to as the broadcast storm problem. Many broadcasting schemes have been proposed to give better performance than simple flooding in wireless sensor network. How to decide whether re-broadcast or not also poses a dilemma between reach ability and efficiency under different host densities. In this paper, we present popular broadcasting schemes, which can reduce re-broadcast packets and improve SRB(Saved ReBroadcast). Simulation results show different levels of improvement over the simple flooding scheme.

Performance Comparison of MISP-based MANET Strong DAD Protocol

  • Kim, Sang-Chul
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.9
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    • pp.3449-3467
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    • 2015
  • A broadcast operation is the fundamental transmission technique in mobile ad-hoc networks (MANETs). Because a broadcast operation can cause a broadcast storm, only selected forwarding nodes have the right to rebroadcast a broadcast message among the one-hop and two-hop neighboring nodes of a sender. This paper proposes the maximum intersection self-pruning (MISP) algorithm to minimize broadcasting redundancy. Herein, an example is given to help describe the main concept of MISP and upper bounds of forward node have been derived based on induction. A simulation conducted demonstrated that when conventional blind flooding (BF), self-pruning (SP), an optimized link state routing (OLSR) multipoint relay (MPR) set, and dominant pruning (DP), are replaced with the MISP in executing Strong duplicate address detection (DAD), the performances in terms of the energy consumption, upper bounds of the number of forward nodes, and message complexity have been improved. In addition, to evaluate the performance in reference to the link error probability, Pe, an enhancement was achieved by computing a proposed retransmission limit, S, for error recovery based on this probability. Retransmission limit control is critical for efficient energy consumption of MANET nodes operating with limited portable energy where Strong DAD reacts differently to link errors based on the operational procedures.

A Cooperative Communication System using Cross-Layer Coding Method base on Hybrid-ARQ (Cross-Layer 부호기법을 이용한 Hybrid-ARQ 기반의 협력통신 시스템 연구)

  • Park, Tae-Doo;Kim, Min-Hyuk;Kim, Chul-Seung;Jung, Ji-Won
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.11C
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    • pp.889-895
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    • 2010
  • MIMO system generally requires more than one antenna at the communication device. However, many wireless devices are limited by size, cost or hardware complexity to one antenna. To overcome such restrictions, we used a new technique, called cooperative communication. We propose a new cooperative transmission strategy system using cross-layer coding method base on H-ARQ for optimal communication. Proposed cooperative H-ARQ system that can improve the above problems and can get the better performance. In proposed cooperative system with H-ARQ method, if the received signal from source node is satisfied by the destination preferentially, the destination transmit ACK message to both relay node and source node, and then recovers the received signal. In addition, if ARQ message indicates NACK message, relay node operates selective retransmission. Based on the simulation results in aspect to BER performance and throughput, the proposed method which combined cooperative system with H-ARQ based on cross-layer coding can improve spectral efficiency reliability of system compared with that of general one by one system.

Data hub system based on SQL/XMDR message using Wrapper for distributed data interoperability (분산 데이터 상호운용을 위한 SQL/XMDR 메시지 기반의 Wrapper를 이용한 데이터 허브 시스템)

  • Moon, Seok-Jae;Jung, Gye-Dong;Choi, Young-Keun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.11
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    • pp.2047-2058
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    • 2007
  • The business environment of enterprises could be difficult to obviate redundancy to filtrate data source occurred on data integrated to standard rules and meta-data and to produce integration of data and single viewer in geographical and spatial distributed environment. Specially, To can interchange various data from a heterogeneous system or various applications without types and forms and synchronize continually exactly integrated information#s is of paramount concern. Therefore data hub system based on SQL/XMDR message to overcome a problem of meaning interoperability occurred on exchanging or jointing between each legacy systems are proposed in this paper. This system use message mapping technique of query transform system to maintain data modified in real-time on cooperating data. It can consistently maintain data modified in realtime on exchanging or jointing data for cooperating legacy systems, it improve clarity and availability of data by providing a single interface on data retrieval.

Expediting Data through Erasure Coding in Networks with High Coefficient of Variation of Transfer Time (전송시간의 변화가 큰 네트워크에서 이레이저 코딩을 적용한 긴급 데이터 전송 방법 및 성능 분석)

  • Lee, Goo Yeon;Lee, Yong
    • Journal of Digital Contents Society
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    • v.15 no.2
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    • pp.137-145
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    • 2014
  • In this paper, we focus on end-to-end transfer delay improvement by using erasure coding when delivering expediting message consisting of M packets in networks with high coefficient of variation of transfer time. In the scheme, M packets are divided into b groups with each having g packets. Each group is erasure coded with additional r packets and transmitted. Since the first arrived g packets among g+r packets completes the delivery of the group, the delivery time of the expediting message is reduced. For the scheme, we investigate the optimum group size and number of redundancy packets considering delivery delay reduction and additional transmission cost caused by using erasure coding. From the results of the investigation, we see that the proposed scheme is effective in networks having high variability of transfer time and would be very useful and practical especially for the case that expedited deliveries of messages are needed.

An On-demand Station Location Management scheme using 6-address structure of IEEE 802.11s (IEEE 802.11s 6-Address 구조를 이용한 On-demand 방식 단말 위치 관리기법)

  • Jang, Jeong-Hun;Kong, Jong-Min;Kim, Jong-Deok
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.4
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    • pp.829-836
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    • 2013
  • Wireless mesh networks(WMNs) are wireless backbone networks technology consisting of a multi-hop routers. Location management is essential to provide a service to the terminal in WMNs. IEEE 802.11s standards have two basic location management scheme for location management - the proxy registration procedure and the associated station discovery protocol. These basic schemes, however, suffer from serious drawbacks including redundancy control message, ineffective location information maintenance, additional delay time. This paper propose an on-demand station location management scheme using 6-address structure of IEEE 802.11s. Through analysis and experimental evaluation on simulation, we show that proposal scheme reduce control message and forwarding delay time.

A study of an effective teaching of listening comprehension (영어 청해력 향상을 위한 효율적인 학습 지도 방안)

  • Park, Chan-Shik
    • English Language & Literature Teaching
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    • no.1
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    • pp.69-108
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    • 1995
  • Listening comprehension can be defined as a process of an integrative, positive and creative activity through which listeners get the message of speakers' production using linguistic or non-linguistic redundancy as well as linguistic or non-linguistic knowledge. Compared with reading comprehension, it has many difficulties especially for foreigners. while it can be transferred to the other skills: speaking, reading, writing. With this said, listening comprehension can be taught effectively using the following teaching strategies. First. systematic and intensive instruction of segmental phonemes, suprasegmental phonemes and sound changes must be given to remove the difficulties of listening comprehension concerned with the identification of sounds. Second, vocabulary drill through various games and other activities is absolutely needed until words can be unconsciously recognized. Without this, comprehension is almost impossible. Third, instruction of sentence structures is thought to be essential considering grammar is supplementary to listening comprehension and reading comprehension for academic purpose. So grammar translation drills, mechanical drills, meaningful drills and communicative drills should be performed in succession with common or frequently used structures. Fourth, listening activities for overall comprehension should teach how to receive overall meaning of intended messages intact. Linguists and literatures have listed some specific activities as follows: Total Physical Response, dictation, role playing, singing songs, selective listening, picture recognition, list activities, completion, prediction, true or false choice, multiple choice, seeking of specific information, summarizing, problem-solving and decision-making, recognization of relationships between speakers, recognition of mood, attitude and behavior of speakers.

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Reliable Gossip Zone for Real-Time Communications in Wireless Sensor Networks

  • Li, Bijun;Kim, Ki-Il
    • Journal of information and communication convergence engineering
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    • v.9 no.2
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    • pp.244-250
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    • 2011
  • Gossip is a well-known protocol which was proposed to implement broadcast service with a high reliability in an arbitrarily connected network of sensor nodes. The probabilistic techniques employed in gossip have been used to address many challenges which are caused by flooding in wireless sensor networks (WSNs). However, very little work has yet been done on real-time wireless sensor networks which require not only highly reliable packets reception but also strict time constraint of each packet. Moreover, the unique energy constraining feature of sensor makes existing solutions unsuitable. Combined with unreliable links, redundant messages overhead in real-time wireless sensor networks is a new challenging issue. In this paper, we introduce a Reliable Gossip Zone, a novel fine-tailored mechanism for real-time wireless sensor networks with unreliable wireless links and low packet redundancy. The key idea is the proposed forwarding probability algorithm, which makes forwarding decisions after the realtime flooding zone is set. Evaluation shows that as an oracle broadcast service design, our mechanism achieves significantly less message overhead than traditional flooding and gossip protocols.