• Title/Summary/Keyword: transmission control schemes

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A Robust Energy Saving Data Dissemination Protocol for IoT-WSNs

  • Kim, Moonseong;Park, Sooyeon;Lee, Woochan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.12
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    • pp.5744-5764
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    • 2018
  • In Wireless Sensor Networks (WSNs) for Internet of Things (IoT) environment, fault tolerance is a most fundamental issue due to strict energy constraint of sensor node. In this paper, a robust energy saving data dissemination protocol for IoT-WSNs is proposed. Minimized energy consumption and dissemination delay time based on signal strength play an important role in our scheme. The representative dissemination protocol SPIN (Sensor Protocols for Information via Negotiation) overcomes overlapped data problem of the classical Flooding scheme. However, SPIN never considers distance between nodes, thus the issue of dissemination energy consumption is becoming more important problem. In order to minimize the energy consumption, the shortest path between sensors should be considered to disseminate the data through the entire IoT-WSNs. SPMS (Shortest Path Mined SPIN) scheme creates routing tables using Bellman Ford method and forwards data through a multi-hop manner to optimize power consumption and delay time. Due to these properties, it is very hard to avoid heavy traffic when routing information is updated. Additionally, a node failure of SPMS would be caused by frequently using some sensors on the shortest path, thus network lifetime might be shortened quickly. In contrast, our scheme is resilient to these failures because it employs energy aware concept. The dissemination delay time of the proposed protocol without a routing table is similar to that of shortest path-based SPMS. In addition, our protocol does not require routing table, which needs a lot of control packets, thus it prevents excessive control message generation. Finally, the proposed scheme outperforms previous schemes in terms of data transmission success ratio, therefore our protocol could be appropriate for IoT-WSNs environment.

Community development and parasite control (지역사회개발(地域社會開發)과 기생충(寄生虫))

  • Rim, Han-Jong
    • Journal of agricultural medicine and community health
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    • v.1 no.1
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    • pp.10-21
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    • 1976
  • The traditional application of night soil to vegetable gardens and rice paddies results in a most wide spread condition of parasitism, with a variety of helminths found in Korea. In addition to the above fact, the peculiar habit of the consumption of raw vegetables, fish, crustaceans and mammals provides a means of infestations of helminths. During the last sixty years numerous reports were found on the prevalence of helminths amongst the Korean population in different parts of the country, and it was generally recognized that ascariasis, hookworm disease, filariasis, clonorchiasis and paragonimiasis constitute the important helminthic disease in Korea. In practical measures of parasite control activities the main measures are summarized as mass-treatment, night-soil disposal and transmission control. Among the three, the mass-treatment has been commonly applied, however, no reduction of transmission has been obtained by treatment of a population. Therefore, the ultimate eradication of parasites will depend upon the application of comprehensive environmental sanitation measures. The basic environmental measures will be concerned with (a) the safe disposal of human excreta, (b) the provision of adequate and safe water supplies in such a way as to promote a higher standard of personal hygiene in the population, and (c) the prevention of food contamination by faecal material. Additional environmental measures will deal with the improvement of housing and housing hygiene and with general community development. Community development means social and cultural as well as economic development. The control measures on the parasitic endemic diseases, such as clonorchiasis and paragonimiasis are the good examples for community health development in Korea. The control of Clonorchis and Paragonimus infections are theoretically very simple, as the infection can only invade the human body by way of encysted metacercaria which are taken into the body when eating passive intermediate hosts(fishes, crabs and crayfishes). Although prophylactic measures in the case of the infections deal with above merely consist the fishes in cooking or submerging in hot water before eating them, it is exceedingly difficult to carry out such simple measures in face of century old traditions, to which the relatively primitive population clings with great tenacity. There is no one universally applicable method of control. The choice of methods must be dictated by the nature of the environment. the habit and custom of the people. the pattern of transmission and the resources of the country. There must exist a well organized public health infrastructure. Since a control programme is of necessity on a longterm basis and continuity in its implementation is essential. An investigation should be made on the prevalence of the diseases and its relationships to irrigation engineering, freshwater ecology, agricultural methods, hydro-electric schemes, and the development of communities in affected areas. In conclusion, however. the control of clonorchiasis and paragonimiasis in Korea is not an impossible task. A combination of efforts with major emphasis on health education and mass chemotherapy coupled with governmental aid in enforcing legislative public health measures could reduce the diseases. Health education in particular attempts following four things: (a) It supplies a person with enough general knowledge about a disease to make the preventive measures. (b) It makes a person feel sufficiently about the importance of his own health to make him alter his behavior and adopt these preventive measure. (c) It makes him concerned for the health others. (d) It tries to make him feel so strongly about the first three that be supports and even initiates preventive action by the community. Educational efforts should be directed primarily toward school children because it is during the early years that most persons become infected, and also because children are less entrenched in their food habits so that, the educational process should be involved at various levels in successive changes of knowledge, attitude, beha viour, habit and custom of their lives. The most parasitic endemic diseases are related to community diseases. In caring for a sick community. the first stage is to gather epidemiological data, the next is to make inferences from it-to make the community diagnosis. The third is to prescribe community treatment or community health action part of a community health action programme. The community health action is the sum of the steps decided upon to remedy the critical features revealed by the community diagnosis. Action takes various forms; health education is the most important.

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Study of Scene change Detection and Adaptive Rate Control Schemes for MPEG Video Encoder (MPEG 비디오 인코더를 위한 장면전환 검출 및 적응적 율 제어 방식 연구)

  • Nam, Jae-Yeol;Gang, Byeong-Ho;Son, Yu-Ik
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.2
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    • pp.534-542
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    • 1999
  • A sell-designed rate control strategy can improve overall picture quality for video transmission over a constant bit rate channel and the rate control method is not a normative part of MPEG-video standard, the performance of MPEG video codec can be quite different depends on how to implement the rate control scheme. The rate control scheme proposed in MPEG show good results when scene changes is not occurred. But it has weakness that it does not properly handle scene-changed pictures. Therefore picture quality after scene change is deteriorated, and possibility of overflow occurrence becomes high. In this paper, a new method for detection of scene change occurrence using local variance and a new determination scheme for adaptive quantization parameter, mqunt, which can consider local characteristic of an image by using previously computed the local variance from the scene change detection part are proposed. IN addition, and adaptive rate control scheme which can handles scene changed picture very efficiently by scene-changed picture is proposed. Computer simulations are performed to verify the performance of the proposed algorithm. The suggested detection algorithm precisely detected scene change. And the proposed rate control scheme shows better rate control performance as compared with that of the conventional MPEG scheme.

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Transmission of Continuous Media by Send-rate Control and Packet Drop over a Packer Network (패킷망에서 전송율 제어와 패킷 폐기에 의한 연속 미디어 전송방안)

  • 배시규
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 1999.12a
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    • pp.121-129
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    • 1999
  • When continuous media are transmitted over the communication networks, asynchrony which can not maintain temporal relationships among packets may occur due to a random transit delay. There exist two types of synchronization schemes ; for guaranteed or non-guaranteed resource networks. The former which applies a resource reservation technique maintains delay characteristics, however, the latter supply a best-effort service. In this paper, I propose a intra-media synchronization scheme to transmit continuous media on general networks not guaranteeing a bounded delay tome. The scheme controls transmission times of the packets by estimating next delay time with the delay distribution. So, the arriving packets may be maintained within a limited delay boundary, and playout will be performed after buffering to smoothen small delay variations. The continually increasing delay due to network overload causes buffer underflow at the receiver. To solve it, the transmitter is required to speed up instantaneously. Too much increase of transmission-rate may cause network congestion. At that time, the transmitter drops the current packet when informed excessive delay from the receiver.

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Design and Implementation of an Adaptive Synchronization Algorithm of the MPEG Stream for VOD Services (VOD 서비스를 위한 MPEG 스트림의 적응적 동기화 알고리즘 설계 및 구현)

  • Jo, Dae-Je;Lee, Yeong-Hu;Yoo, Kee-Young
    • Journal of KIISE:Computing Practices and Letters
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    • v.6 no.5
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    • pp.505-512
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    • 2000
  • In this paper, an adaptive multimedia synchronization scheme for VOD (Video On Demand) services in internet environments is proposed. This scheme considers the characteristics of MPEG (Moving Picture Expert Group) system stream. Consequently, the intra-synchronization is handled at the pack layer, and the inter-synchronization is handled at the packet layer. The proposed scheme can cope adaptively with variation of packet loss, jitter and client's playback capacity. If there are variations of the packet loss or client's playback capacity, the server will change the transmission rate by selective picture skip. The client can then adjust and control the playback time according to the variation of the network jitter. Our experimental results show that the proposed scheme can quickly adapt to the network condition, and can guarantee a better quality of service than the other existing schemes.

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Dynamic Resource Allocation Method to improve QoS in the Wireless ATM Networks (무선 ATM망에서 QoS 향상을 위한 동적 자원 할당 방식)

  • Kim, Seung-Hwan;Lee, Sun-Sook;Lee, Jae-Hong;Jang, Dong-Heyok
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.9
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    • pp.2940-2947
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    • 2000
  • In the wireless ATM networks, a Medium Access Control (MAC) protocol is required to support an integrated mix of multimedia traffic services. The MAC protocol should be designed in a way that the limited wireless bandwidth can be efficiently utilized maximizing the Quality of Service (QoS) guarantees for various traffic service classes. In this paper, a Dynamic Resource Allocation-based MAC protocol, which satisfies QoS of each traffic service class in the wireless ATM environment, is proposed. The proposed MAC protocol adopts the dynamic channel allocation schemes for a mix of different traffic service classes. The suggested MAC protocol is designed to provide the QoS guarantees for Constant Bit Rate (CBR) or real-time Variable Bit Rate (VBR) traffic through fixed or dynamic reservation. For Available Bit Rate (ABH) traffic, which has the lowest priority among the traffic classes, large improvement in delay by reserving the minimum bandwidth is shown. And for real-time VBR traffic, increase in throughput of transmission is demonstrated because of bandwidth, which is allocated through contention at the initial phase and without contention thereafter.

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Random Channel Allocation Scheme Based on Split Algorithm in HIPERLAN 2 (HIPERLAN Type 2에서 Split 알고리즘에 기반한 랜덤채널 할당 기법)

  • 황의석;고유창;이승규;윤철식;이형우;조충호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.9A
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    • pp.717-727
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    • 2003
  • The HIPERLAN/2(HIgh PERformance Local Area Network Type2) is one of the wireless LAN standards for providing raw data rates of up to 54 Mbps. The MAC protocol of HIPERLAN/2 is based on TDMA/TDD, and resources in one MAC frame can be allocated dynamically by Access Point(AP). The random channel(RCH) is defined for the purpose of giving a mobile terminal the opportunity to request transmission resources in the uplink MAC frames. It is desirable that the number of RCHs is dynamically adapted by the AP depending on the current traffic situation. Allocation of excessive RCHs may waste radio resources and insufficient RCHs compared to traffic loads may result in many collisions in access attempts. We propose an RCH allocation scheme based on split algorithm in HIPERLAN/2. The simulation and analytic results show that the proposed scheme achieves a higher channel throughput, lower access delay and delay jitter than previously proposed RCH allocation schemes.

Performance Enhancement of Proxy Mobile IPv6 using Binding Query (Binding Query를 활용한 Proxy Mobile IPv6의 성능 향상 기법)

  • Park, Jae-Wan;Kim, Ji-In;Koh, Seok-Joo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.11B
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    • pp.1269-1276
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    • 2011
  • In the Proxy Mobile IPv6 (PMIPv6), the data transmission performance may be degraded when the two communicating hosts are located within the same mobile domain, since all the data packet shall be delivered by way of Local Mobility Anchor (LMA). In this paper we propose an extensional scheme of PMIPv6 using binding query. In the proposed Query-based PMIPv6 (Q-PMIPv6) scheme, the Mobile Access Gateway (NAG) of Correspondent Node (CN) sends a binding query to LMA to obtain the Proxy Care-of-Address of Mobile Node (MN). Since then, CN and MN can communicate with each other by using an optimized data path. For comparison, we performed the numerical analysis and the ns-2 simulations for the proposed Q-PMIPv6 scheme and the existing PMIPv6 and PMIPv6 Localized Routing (PMIPv6-LR). From the results, we can see that the proposed scheme outperforms the existing PMIPv6 and PMIPv6-LR schemes in terms of the signaling control and data delivery costs.

An Effective Solution to Overcome the Restriction of SACK Blocks' Number in TCP SACK (오프셋을 활용한 효율적인 TCP SACK 메커니즘)

  • Lin, Cui;Hong, Choong-Seon
    • The KIPS Transactions:PartC
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    • v.12C no.7 s.103
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    • pp.1039-1046
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    • 2005
  • TCP SACK is the unique mechanism to reflect the situation of sink's sequence space, some TCP variants and proposals can perform in conjunction with SACK mechanism for achieving optimal performance. By definition of RFC 2018, however, each contiguous block of data queued at the data receiver is defined in the SACK option by two 32-bit unsigned integers in network byte order. Since TCP Options field has a 40-byte maximum length, when error bursts now, we note that the available option space may not be sufficient to report all blocks present in the receiver's queue and lead to unnecessarily force the TCP sender to retransmit Packets that have actually been received by TCP sink. For overcoming this restriction, in this thesis, a new solution named 'one-byte offset based SACK mechanism' is designed to further improve the performance or TCP SACK and prevent those unwanted retransmissions. The results or both theory analysis and simulation also show that his proposed scheme operates simply and more effectively than the other existing schemes by means of the least bytes and most robust mechanism to the high packet error rates often seen in networks environment.

An Enhanced Fast Handover Scheme for Real-Time Traffic in IPv6 Based WiBro Network (IPv6기반 와이브로 시스템에서 실시간 트래픽을 위한 개선된 빠른 핸드오버 방안)

  • Jeong, Seok-Jong;Lee, Sung-Kuen;Park, Jin-Woo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.4A
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    • pp.377-386
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    • 2008
  • In this paper, a new handover management scheme has been proposed to reduce handover latency and to support fast handover without packet losses, so that it may be applicable to the wireless mobile Internet system such as IPv6-based WiBro system. To minimize the handover latency in processing of movement detection, we propose the handover management scheme which simplifies the handover message exchanging procedure between mobile subscriber station (MSS) and network by integrating layer 2 and layer 3 handovers efficiently based on the layer2 information. To reduce the processing delay from new care-of-address (NCoA) configuration during handover, we propose that NCoA is created, distributed and managed by new access control router (NACR). In addition, in order to minimize the packet transmission delay and eliminate the packet losses, the proposed scheme employs a crossover router (CR) which is upper network located over PACR and NACR and employs the packet buffering for MSS. The simulation study shows that the proposed scheme achieves loss-free packet delivery and low latency in the environment of narrow overlapped cell area or high velocity of the MSS, comparing the performance with the conventional schemes.