• Title/Summary/Keyword: networking services

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A Handover Mechanism in Internetworking with UMTS/WLAN based on HMIPv6 (HMIPv6 기반의 UMTS/WLAN 연동 네트워크에서의 핸드오버 방안)

  • Jeong Eunjoo;Park Sangjun;Lee Hyewon K.;Kim Jaeha;Kim Byunggi
    • Journal of KIISE:Information Networking
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    • v.32 no.4
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    • pp.508-514
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    • 2005
  • The research in internetworking between UMTS and WLAN, which is completed with merits and demerits, Is actively progressed to establish global roaming environments. This internetworking is classified into two groups: loosely-coupled and tightly-coupled. h tightly-coupled mechanism demands lots of investment and considerable amountof time to construct, which is directly connoted between UNTS and WLAN via IWU. On the other hand, a tersely-coupled mechanism is more scalable and easier to implement than a tightly-coupled one while it has critical drawbacks of packet loss and blocking of services due to handover delay. To alleviate these drawbacks. this work proposes a handover scheme between UMTS and WLAN, which is based on HMIPv6. The performance of the proposed scheme is evaluated by the simaulation. The proposed internetworking scheme based on HMIPv6 shows hotter performance than those based on MIPv6.

A New Available Bandwidth Measurement Technique with Accurate Capacity Estimation (정확한 고정대역폭 추정을 통한 새로운 가용대역폭 측정 기법)

  • Cho Seongho;Choe Han;Kim Chong-kwon
    • Journal of KIISE:Information Networking
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    • v.32 no.4
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    • pp.495-507
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    • 2005
  • Measuring the end-to-end available bandwidth in the Internet is a useful tool for distributedapplication services or QoS (Quality-of-Service) guarantee. To measure the end-to-end available bandwidth, Single-hop Gap model-based packet train measurement techniques are well-known. However, the error of packet train output gap can happen by network topologies. This error of the output gap causes the inaccuracy of the available bandwidth measurement. In this paper, we propose a new end-to-end available bandwidth measurement technique with accurate capacity measurement and fast convergence methods. To solve the erroneous capacity measurement problem of the back-to-back packet train transmission, we propose a new available bandwidth measurement method by decoupling the capacity measurement with the initial gap of the packet train. Also, we propose a new technique to predict the proper initial gap of the packet train for faster convergence. We evaluate our proposed method by the simulation in various topologies comparing with previous methods.

The Effects of Image Based Fashion Brands' SNS Toward Flow and Brand Attitude : Focus on Pleasure Emotion as Mediator (패션 브랜드 이미지 기반 SNS가 플로우, 브랜드 태도에 미치는 영향 : 즐거움 감정의 매개변수를 중심으로)

  • Ko, Jeonmi;Shin, Jiye;Ko, Eunju;Chae, Heeju
    • The Korean Fashion and Textile Research Journal
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    • v.16 no.6
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    • pp.908-920
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    • 2014
  • As social networking service (SNS) users' needs and wants have become more diverse, SNS is designed to provide various services and functions. As a result, an image based SNS with the purpose of sharing various interests has emerged. More and more fashion companies are using image based SNS to use it as a medium to better communicate with their customers. This study investigates the effect of usage motivation of image based SNS with the emotion of pleasure as the mediator and its impact towards flow and brand attitude. In order to verify the research model and to test the proposed hypotheses, we conducted a pilot test on 8 image based SNS heavy users, and followed through with 215 questionnaires which were collected via online survey. The results of this study are as follows. Each usage motivation of image based SNS had significant effect on each pleasure. The visual impact had a positive effect on sensory pleasure and the common interest significantly influenced on user's affective preference. Curating, simplicity and interconnecting had a positive effect on cognitive pleasure. Affective and cognitive pleasures except sensory pleasure positively impacted the user on flow. The cognitive pleasure had a positive effect on the brand attitude. Lastly, flow had a positive effect on the brand attitude. This study is the foundation of the image based SNS academically in the new media research. Furthermore, it suggests managerial implications of a company to provide effective marketing strategy to make the best use of image based SNS.

Traffic Engineering and Manageability for Multicast Traffic in Hybrid SDN

  • Ren, Cheng;Wang, Sheng;Ren, Jing;Wang, Xiong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.6
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    • pp.2492-2512
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    • 2018
  • Multicast communication can effectively reduce network resources consumption in contrast with unicast. With the advent of SDN, current researches on multicast traffic are mainly conducted in the SDN scenario, thus to mitigate the problems of IP multicast such as the unavoidable difficulty in traffic engineering and high security risk. However, migration to SDN cannot be achieved in one step, hybrid SDN emerges as a transitional networking form for ISP network. In hybrid SDN, for acquiring similar TE and security performance as in SDN multicast, we redirect every multicast traffic to an appropriate SDN node before reaching the destinations of the multicast group, thus to build up a core-based multicast tree substantially which is first introduced in CBT. Based on the core SDN node, it is possible to realize dynamic control over the routing paths to benefit traffic engineering (TE), while multicast traffic manageability can also be obtained, e.g., access control and middlebox-supported network services. On top of that, multiple core-based multicast trees are constructed for each multicast group by fully taking advantage of the routing flexibility of SDN nodes, in order to further enhance the TE performance. The multicast routing and splitting (MRS) algorithm is proposed whereby we jointly and efficiently determine an appropriate core SDN node for each group, as well as optimizing the traffic splitting fractions for the corresponding multiple core-based trees to minimize the maximum link utilization. We conduct simulations with different SDN deployment rate in real network topologies. The results indicate that, when 40% of the SDN switches are deployed in HSDN as well as calculating 2 trees for each group, HSDN multicast adopting MRS algorithm can obtain a comparable TE performance to SDN multicast.

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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Management, Orchestration and Security in Network Function Virtualization (네트워크 기능 가상화 관리 및 오케스트레이션 기능과 보안)

  • Kim, Hyuncheol
    • Convergence Security Journal
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    • v.16 no.2
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    • pp.19-23
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    • 2016
  • The design, management, and operation of network infrastructure have evolved during the last few years, leveraging on innovative technologies and architectures. With such a huge trend, due to the flexibility and significant economic potential of these technologies, software defined networking (SDN) and network functions virtualization (NFV) are emerging as the most critical key enablers. SDN/NFV enhancing the infrastructure agility, thus network operators and service providers are able to program their own network functions (e.g., gateways, routers, load balancers) on vendor independent hardware substrate. They facilitating the design, delivery and operation of network services in a dynamic and scalable manner. In NFV, the management and orchestration (MANO) orchestrates other specific managers such as the virtual infrastructure manager (VIM) and the VNF Manager (VNFM). In this paper, we examine the contents of these NFV MANO systematically and proposes a security system in a virtualized environment.

GENESIS: An Automatic Signature-generating Method for Detecting Internet Disk P2P Application Traffic (GENESIS: Internet Disk P2P 트래픽 탐지를 위한 시그너춰 자동 생성 방안)

  • Lee, Byung-Joon;Yoon, Seung-Hyun;Lee, Young-Seok
    • Journal of KIISE:Information Networking
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    • v.34 no.4
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    • pp.246-255
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    • 2007
  • Due to the bandwidth-consuming characteristics of the heavy-hitter P2P applications, it has become critical to have the capability of pinpointing and mitigating P2P traffic. Traditional port-based classification scheme is no more adequate for this purpose because of newer P2P applications, which incorporating port-hopping techniques or disguising themselves as HTTP-based Internet disk services. Alternatively, packet filtering scheme based on payload signatures suggests more practical and accurate solution for this problem. Moreover, it can be easily deployed on existing IDSes. However, it is significantly difficult to maintain up-to-date signatures of P2P applications. Hence, the automatic signature generation method is essential and will be useful for successful signature-based traffic identification. In this paper, we suggest an automatic signature generation method for Internet disk P2P applications and provide an experimental results on CNU campus network.

An Extension of DONet Protocol to Support Private Networks (사설망을 지원하는 확장된 DONet 프로토콜)

  • Lee, Moon-Soo;Han, Sung-Min;Park, Sung-Yong
    • Journal of KIISE:Information Networking
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    • v.35 no.4
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    • pp.268-281
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    • 2008
  • It is difficult to construct streaming services based on the overlay networks without any loss of scalability. DONet is one of the most representative streaming overlay network protocols without managing any specific structure. Since DONet does not support the nodes on private networks, it can be considered that the performance of the overlay is not the best. Hole Punching is one of the famous techniques participating the nodes on private networks to streaming overlay networks by using a rendezvous server. However, using only a single rendezvous server cannot be suggested in P2P environment, because it can cause problems in terms of scalability and so on. In this paper, we propose DONet-p, an extension of DONet with Distributed Hole Punching techniques. It supports the nodes on private networks without toss of scalability. The experimental results show the better performance and scalability than DONet with a minimum overhead for additional control messages.

A Study on Improvement of Residential Environment Service in Rural Village by Applying Service Design Methodology - Focused on Dosan 2-ri Village, Janggok-myeon, Hongseong-gun, Chungcheongnam-do - (서비스 디자인 방법론을 적용한 농촌 마을 주거환경 서비스 개선 연구 - 충청남도 홍성군 장곡면 도산2리 마을을 중심으로 -)

  • Yu, A-Hyeon;Cho, Kwang-Soo;Kim, Sang-Bum
    • Journal of the Korean Institute of Rural Architecture
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    • v.22 no.3
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    • pp.49-60
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    • 2020
  • The purpose of this study utilizes the service design methodology centered on the lives and experiences of rural residents, who are the main beneficiaries of the service, to derive specific problems and needs, and to propose a service improvement plan suitable for the rural residential environment. The study selected Dosan 2-ri Village, Hongseong-gun, Chungcheongnam-do as the target of the survey, used personas and Customer Journey map of service design method to derive specific core issues and insights from the village residents. By developing this, the final five service directions for 'Air care service', 'Self-driving garbage collection and treatment service', 'Emergency/disaster networking service', 'Contaminant removal service' and 'Mobility share service' were derived and presented according to each key keyword. This study is not just a study to grasp the actual conditions of the rural residential environment, but it focuses on the lives and experiences of rural residents and extracts elements that can respond to changes in the lifestyles and patterns of the residents. It can be used as a basic material for more realistic improvement of rural residential environment and service development research. Most of the existing studies on residential environments and spaces is focused on urban areas, and there is a limit to the use of rural areas in residential areas. Therefore, by making recommendations for improvement of residential environment services suitable for rural areas and by creating residential spaces and environments in rural areas in a comfortable and safe manner, it is thought that it is possible to contribute to improvement of satisfaction in rural areas and improvement of healthy housing welfare as well as to improvement of the quality of life of residents of rural areas.

A Study on Accelerometer Based Motion Artifact Reduction in Photoplethysmography Signal (가속도계를 이용한 광전용적맥파의 동잡음 제거)

  • Kang, Joung-Hoon;Cho, Baek-Hwan;Lee, Jong-Shill;Chee, Young-Joon;Kim, In-Young;Kim, Sun-I.
    • Journal of Biomedical Engineering Research
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    • v.28 no.3
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    • pp.369-376
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    • 2007
  • With the convergence of ubiquitous networking and medical technologies, ubiquitous healthcare(U-Healthcare) service has come in our life, which enables a patient to receive medical services at anytime and anywhere. In the u-Healthcare environment, intelligent real-time biosignal aquisition/analysis techniques are inevitable. In this study, we propose a motion artifact cancelation method in portable photoplethysmography(PPG) signal aquisition using an accelerometer and an adaptive filter. A preliminary experiment represented that the component of the pedestrian motion artifact can be found under 5Hz in the spectral analysis. Therefore, we collected PPG signals under both simulated conditions with a motor that generates circular motion with uniform velocity (from 1 to 5Hz) and a real walking condition. We then reduced the motion artifact using a recursive least square adaptive filter which takes the accelerometer output as a noise reference. The results showed that the adaptive filter can remove the motion artifact effectively and recover peak points in PPG signals, which represents our method can be useful to detect heart rate in real walking condition.