• Title/Summary/Keyword: communication networks

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Protocol converting method for the Real-time Safety Supervision System in Railway (실시간 철도안전 관제를 위한 프로토콜 변환 방안 연구)

  • Ahn, Jin;Kim, Sung-Min
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.7
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    • pp.1335-1341
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    • 2016
  • For the safety of train operation, monitoring & supervisory systems for train, signal, power, communication and facilities is operating independently in another place, so, its sensors are interdependently connected from each other to transfer gathering datas of sensing to control center. A Goal of Real-time railway safety supervision system is to improve the safety oversight efficiency and to prevent accidents by means of hazard prediction based on big data by integrating all of safety sensing data in wayside of railway, and the System is requested acquisition of all of sensing data of safety. So, we need special method of protocol converting for the purpose of integrating all of detecting data concerning safety without any changing application. In this paper we investigate the existing converting method in communication field, and propose a new progress to converting protocol adding function of transfer using XML file, and implemented this algorithm, and tested with example packets, finally.

Dynamic Full-Scalability-Conversion in SVC (스케일러블 비디오 코딩에서의 실시간 스케일러빌리티 변환)

  • Lee, Dong-Su;Bae, Tae-Meon;Ro, Yong-Man
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.43 no.6 s.312
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    • pp.60-70
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    • 2006
  • Currently, Scalable Video Coding (SVC) is being standardized. By using scalability of SVC, QoS managed video streaming service is enabled in heterogeneous networks even with only one original bitstream. But current SVC is insufficient to dynamic video conversion for the scalability, thereby the adaptation of bitrate to meet a fluctuating network condition is limited. In this paper, we propose dynamic full-scalability conversion method for QoS adaptive video streaming in H.264/AVC SVC. To accomplish full scalability dynamic conversion, we propose corresponding bitstream extraction, encoding and decoding schemes. On the encoder, we newly insert the IDR NAL to solve the problems of spatial scalability conversion. On the extractor, we analyze the SVC bitstream to get the information which enable dynamic extraction. By using this information, real time extraction is achieved. Finally, we develop the decoder so that it can manage changing bitrate to support real time full-scalability. The experimental results showed that dynamic full-scalability conversion was verified and it was necessary for time varying network condition.

Picture archiving and communications systems development and performance results

  • Nam, Ji-Seung;Ralph Martinez
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10b
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    • pp.1796-1800
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    • 1991
  • Picture Archiving and Communication Systems(PACS) provide an integration of digital imaging information in a hospital, which encompasses various imaging equipment, viewing workstations, database archive systems, and a high speed fiber optic network. One of the most important requirements for integration is the standardization of communication protocols to connect devices from different vendors. Since 1985, the ACR-NEMA standard provides a hardware interface, a set of software commands, and a consistent set of data formats for point-to-point interconnection of medical equipment. However, it has been shown to be inadequate for PACS networking environments, because of its point-to-point nature and its inflexibility to allow other services and protocols in the future. Based on previous experience of PACS developments in The University of Arizona, a new communication protocol for PACS networks has been suggested to the ACR-NEMA Working Group VI. The defined PACS protocol is intended to facilitate the development of PACS's capable of interfacing with other hospital information systems. Also, it is intended to allow the creation of diagnostic information data bases which can be interrogated by a variety of distributed devices. A particularly important goal is to support communications in a multivendor environment. The new protocol specifications are defined primarily as a combination of the International Organization for Standardization / Open Systems Interconnection (ISO/OSI) protocols and the data format portion of ACR-NEMA standard. This paper addresses the specification and implementation of the proposed PACS protocol into network node. The protocol specification, which covers Presentation, Session, Transport, and Network layers, is summarized briefly. The implementation has natural extentions to Global PACS environments. The protocol implementation is discussed based on our implementation efforts in the UNIX Operating System Environment. At the same time, results of performance evaluation are presented to demonstrate the implementation of defined protocol. The testing of performance analysis is performed on the PACS prototype node.

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Overhead Reduction Methods in Communication between 6LoWPAN and External Node (6LoWPAN 노드와 외부 노드의 통신 시에 오버헤드 감소 방법)

  • Choi, Dae-In;Enkhzul, Doopalam;Park, Jong-Tak;Kahng, Hyun-K.
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.5B
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    • pp.437-442
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    • 2011
  • As an Internet Engineering Task Force (IETF) Working Group, 6LoWPAN is standardizing the IPv6 packet transfer technology in accordance with IEEE 802.15.4. It has completed two Request for Comments (RFC) documents, one of which, RFC 4944, addresses fragmentation, reassembly, and header compression technologies. In this paper, a communication mechanism is proposed to provide efficient communication between 6LoWPAN and external nodes. In this mechanism, the gateway between 6LoWPAN and external networks serves as the proxy gateway between nodes. The simulation was conducted using QualNet to compare the performance of the proposed mechanism and the existing RFC 4944 method. The comparative analysis of the proposed mechanism and the existing method showed that the proposed method performed better.

A Study about weight grant of Authentication level in USN environment

  • Choi, Bae-Young;Ahn, Byung-Ryul;Chung, Tai-Myoung
    • Proceedings of the Korea Society of Information Technology Applications Conference
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    • 2005.11a
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    • pp.165-168
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    • 2005
  • The objects, which can be personal digital assistants, electronic rings, doors or even clothes, offer embedded chips with computation facilities and are generally called artifacts. I later realized that this was not so the real problem is actually authentication. Recent results indicate scalability problems for flat ad hoc networks. Sensor network achieves function that handle surrounding information perception through sensor and sensed information to network that is consisted of sensor nodes of large number. Research about new access control techniques and height administration techniques need authentication information persons' certification assurance level classification in sensor network environment which become necessary different view base with authentication information at node for application of AAA technology in USN environment that must do authentication process using information that is collected from various sensor mountings. So, get base authentication information in sensor type and present weight grant model by security strength about authentication information through information who draw. In this paper collected information of sensor nodes model who give weight drawing security reinforcement as authentication information by purpose present be going to. and Must be able to can grasp special quality of each sensor appliances in various side and use this and decide authentication assurance level for value estimation as authentication information elements. Therefore, do to define item that can evaluate Authentication information elements thus and give simple authentication assurance level value accordingly because applying weight. Present model who give authentication assurance level value and weight for quotation according to security strength.

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CNN Based 2D and 2.5D Face Recognition For Home Security System (홈보안 시스템을 위한 CNN 기반 2D와 2.5D 얼굴 인식)

  • MaYing, MaYing;Kim, Kang-Chul
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.6
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    • pp.1207-1214
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    • 2019
  • Technologies of the 4th industrial revolution have been unknowingly seeping into our lives. Many IoT based home security systems are using the convolutional neural network(CNN) as good biometrics to recognize a face and protect home and family from intruders since CNN has demonstrated its excellent ability in image recognition. In this paper, three layouts of CNN for 2D and 2.5D image of small dataset with various input image size and filter size are explored. The simulation results show that the layout of CNN with 50*50 input size of 2.5D image, 2 convolution and max pooling layer, and 3*3 filter size for small dataset of 2.5D image is optimal for a home security system with recognition accuracy of 0.966. In addition, the longest CPU time consumption for one input image is 0.057S. The proposed layout of CNN for a face recognition is suitable to control the actuators in the home security system because a home security system requires good face recognition and short recognition time.

Association Analysis of Convolution Layer, Kernel and Accuracy in CNN (CNN의 컨볼루션 레이어, 커널과 정확도의 연관관계 분석)

  • Kong, Jun-Bea;Jang, Min-Seok
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.6
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    • pp.1153-1160
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    • 2019
  • In this paper, we experimented to find out how the number of convolution layers, the size, and the number of kernels affect the CNN. In addition, the general CNN was also tested for analysis and compared with the CNN used in the experiment. The neural networks used for the analysis are based on CNN, and each experimental model is experimented with the number of layers, the size, and the number of kernels at a constant value. All experiments were conducted using two layers of fully connected layers as a fixed. All other variables were tested with the same value. As the result of the analysis, when the number of layers is small, the data variance value is small regardless of the size and number of kernels, showing a solid accuracy. As the number of layers increases, the accuracy increases, but from above a certain number, the accuracy decreases, and the variance value also increases, resulting in a large accuracy deviation. The number of kernels had a greater effect on learning speed than other variables.

Fixed Partitioning Methods for Extending lifetime of sensor node for Wireless Sensor Networks (WSN환경에서 센서노드의 생명주기 연장을 위한 고정 분할 기법)

  • Han, Chang-Su;Cho, Young-Bok;Woo, Sung-Hee;Lee, Sang-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.5
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    • pp.942-948
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    • 2016
  • WSN based on wireless sensor nodes, Sensor nodes can not be reassigned and recharged if they once placed. Each sensor node comes into being involved to a communication network with its limited energy. But the existing proposed clustering techniques, being applied to WSN environment with irregular dispersion of sensor nodes, have the network reliability issues which bring about a communication interruption with the local node feature of unbalanced distribution in WSN. Therefore, the communications participation of the sensor nodes in the suggested algorithm is extended by 25% as the sensor field divided in the light of the non-uniformed distribution of sensor nodes and a static or a dynamic clustering algorithm adopted according to its partition of sensor node density in WSN. And the entire network life cycle was extended by 14% to ensure the reliability of the network.

ARQ-based Multicast for OFDMA Systems (OFDMA 시스템의 ARQ 기반 멀티캐스트 방법)

  • Kim, Sung-Won
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.1
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    • pp.161-169
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    • 2009
  • Multicast-based data communication is an efficient communication scheme in wireless networks where the Media Access Control (MAC) layer is based on one-hop broadcast from one source to multiple receivers. Compared with unicast, multicast over wireless channel should handle varying channel conditions of multiple users and user mobility to achieve good quality for all users. However, IEEE 802.11 does not support reliable multicast due to its inability to exchange RTS/CTS and ACK with multiple recipients. Thus, several MAC layer protocols have been proposed to provide reliable multicast. For the reliable multicast, an additional overhead is introduced and it degrades the system performance. In this paper, we propose a cross-layer design to reduce the control overhead for reliable multicast in OFDMA systems. We present an analytical formulation of the system throughput associated with the overhead.

Toward Mobile Cloud Computing-Cloudlet for implementing Mobile APP based android platform (안드로이드 기반의 모바일 APP 개발을 위한 모바일 클라우드 컴퓨팅)

  • Nkenyereye, Lionel;Jang, Jong-Wook
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.6
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    • pp.1449-1454
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    • 2015
  • Virtualization lacks capabilities for enabling the application to scale efficiently because of new applications components which are raised to be configured on demand. In this paper, we propose an architecture that affords mobile app based on nomadic smartphone using not only mobile cloud computing-cloudlet architecture but also a dedicated platform that relies on using virtual private mobile networks to provide reliable connectivity through LTE(Long Term Evolution) wireless communication. The design architecture lies with how the cloudlet host discovers service and sends out the cloudlet IP and port while locating the user mobile device. We demonstrate the effectiveness of the proposed architecture by implementing an android application responsible of real time analysis by using a vehicle to applications smartphone interface approach that considers the smartphone to act as a remote users which passes driver inputs and delivers outputs from external applications.