• Title/Summary/Keyword: best-effort service

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Suggestion on FM Service for Improving Students' Satisfaction on the University Dorm Facilities (대학 기숙사의 만족도 향상을 위한 시설관리(FM) 서비스 제안)

  • Kim, Yu-Jin;Shin, Eun-Young;Kim, Jun-Ha
    • Journal of the Korean Institute of Educational Facilities
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    • v.23 no.2
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    • pp.11-18
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    • 2016
  • University dorm basically provides basic housing functions to students, however, it is very important in a sense that it provides students with various functions such as information exchange, cultural experience and learning environments as well. Additionally, continuous effort to improve users' satisfaction and living environments are needed due to the fact that physical environments of dorm facilities have higher impact on students. However, Many students are not satisfied with the physical environment of university dorms and also there is lack of systematic information whereas various functions are required by students. Therefore, the main objective of this research is to suggest the direction of FM services in order for improving students' satisfaction on the university dorm facilities in Korea. Precedent studies regarding the satisfaction or performance evaluation of dorm facilities have been extensively analyzed to extract the dissatisfaction factors that scored below the middle 50%. Secondly, for satisfaction improvement, Korean Standard for Facility Management(KS_FM) have been matched with those extracted dissatisfaction factors to suggest the direction of FM services by rules and regulations review and best practice studies. This research will be useful for university dorm facility managers in planning strategic FM and providing effective FM services to students.

A Performance Analysis of IP Multicasting using Resource Reservation over ATM Networks (ATM 망에서 자원 예약 방식을 이용한 IP 멀티캐스팅의 성능 분석)

  • 봉은철;김동일;최영진;양기원;오창석
    • The KIPS Transactions:PartC
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    • v.8C no.1
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    • pp.41-50
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    • 2001
  • With growth of Internet, real time multimedia application services require guarantee of QoS (Quality of Service). However, the existing Internet based on best-effort service is not enough to support those services, so MARS model to support IP multicast over ATM networks and RSVP to provide heterogeneous QoS by resource reservation scheme are proposed. As a simulation result, it is proved that processing delay of MARS is increased and success of resource reservation is decreased as a number of QoS change request of a receiver is increased. Therefore, it is important to provide heterogeneous QoS that distribute a load of MARS caused by convergence of messages and efficiently manage the resource of network as to find out scale of receivers and frequency of QoS change request.

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Performance Evaluation of the QoS Guarantee Mechanisms for Medical Multimedia Network Using DiffServ (DiffServ를 이용한 의료용 멀티미디어 네트워크의 QoS 보장에 대한 성능평가)

  • 이상학
    • Journal of the Korea Computer Industry Society
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    • v.2 no.12
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    • pp.1505-1516
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    • 2001
  • The goal of Medical multimedia server is to develop computer hardware and software which would enable electronic access, storage, transmission, and display of patient data and images. Since the current network only provides so called "best-effort" services, it is impossible to satisfy QoS guarantee that is required for real time application services for emergency room, operating room etc. Accordingly, world-wide research is being made for a variety of services to provide QoS. he goal of DiffServ is to offer scalable differentiated service in Internet which are made possible by traffic classification and conditioning only performed at an edge(or a boundary) node. In case DiffServ was deployed in the Medical multimedia network, it is difficult to estimate how the QoS mechanism would affect totally the network performance. Therefore, we need to verify by simulation the design of algorithm which provide a variety of differentiated services. In QoS for Medical multimedia network, a simulator is designed and implemented using OPNET to investigate the performance of DiffServ QoS support mechanism. The developed DiffServ simulator may generate packets according to random, and bursty traffic models in order to incorporate diverse traffic conditions in the Medical multimedia network environment. Based on our simulation results, we confirmed that service differentiation is possible by using the EF(Expedited Forwarding) class in DiffServ networks.

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A Study on Network Architecture for Next Generation Optical Internet based DWDM (DWDM 기반의 차세대 광 인터넷 구조에 관한 연구)

  • 배정현;송현수;이재동;김성운
    • Journal of Korea Multimedia Society
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    • v.6 no.3
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    • pp.496-507
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    • 2003
  • Rapidly increasing Internet traffic demands require IP protocol based on high quality networking technology. Accordingy, our Internet has evolved from best-effort service toward differentiated service framework so as to implement QoS as prerequisite to a series of new applications. In addition, it is forecasted that existing transport network will be reorganized into DWDM-based optical Internet sooner or later under the influence of Internet demands for higher bandwidth based on QoS. This study shows a way to an effective implementation in some aspects: QoS implementation on DWDM-based optical Internet network, control protocol, backbone network architecture and switching technology for the Next Generation Internet (NGI).

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A Study on the Adaptive Congestion Control Schemes in ATM LANs (ATM LAN에서 적응적 폭주제어 방식에 관한 연구)

  • Lee, Woo-Seung;Moon, Kyu-Choon;Kim, Hoon;Park, Kwang-Chae
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.129-132
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    • 1999
  • In this Paper, new congention control schemes using the adaptive rate control for ATM LANs are presented. If is preferable for hosts in LANs to be able to send bursts at the same speed as the interface link speed in a lightly loaded condition, and as the network load increases, to reduce their traffic rate adaptively in order to avaid network congestion. We propose to apply such a rate control concept for two different traffic classed in the ATM LANs. For the first traffic class requiring no bandwidth reservation, i.e, a best effort service class, a combination of the end-to-end adaptive peak rate control with the link-by-link backpressure control is proposed. For the second traffic class, requiring the bandwidth reservation for the burst transmission, i.e. guaranteed burst service class, a combination of he adaptive peak rate control with the fast bandwidth reservation is proposed.

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Effective Streaming technology of a layered encoding Video Application supporting QoS mechanism in the Internet

  • Seok, Joo-Myoung;Lee, Kyou ho;Suh, Doug-Young
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.2075-2078
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    • 2002
  • Internet became the most popular network in spite of its weakness in realtime multimedia service. Many experts believe that the Internet has the potential to become the main multimedia distribution network of the near future. Currently, it does not provide any (BoS guarantees and, even when it does, guaranteed quality delivery of video may turn out to be too expensive. Unavoidable packet losses and delay jitter caused by congestion in a best effort delivery environment require use of intelligent transport techniques for effective video delivery. According to market needs of better quality of service (QoS) fur realtime multimedia services over Internet, they have been standardizing RSVP, IntServ, and DiffServ This paper combines the benefits of QoS mechanisms such as RSVP/IntServ with scalable video encoding. We propose that more important bit stream is given more priority such that limited network resources are guaranteed far the stream. Various prioritizing approaches are proposed and compared to normal approach by using Network Simulator. The calculated QoS parameters such as packet loss rate are used to calculate degree of degradation in video quality. In this Paper, proposed methods can be implemented adaptively to Von protocol, such as H.323, SIP.

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Detection of tetracyclines in beef and pork (식육중 테트라사이클린계 항생물질 잔류조사)

  • 박재명;최해연;이은정;조우영;조부제;정운선
    • Korean Journal of Veterinary Service
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    • v.20 no.2
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    • pp.225-233
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    • 1997
  • In an effort to Improve the quality of meat and to monitor farms, residual tetracyclines in local beef and pork produced in the province of North Chung-cheong were determined by a EEC 4-plate, Charm II and HPLC, respectively. The results were summarized as follows ; 1. Of the 547 samples, 4 beef and 13 pork samples were judged to be positive by EEC 4 - plate method. 2. Detection rates of tetracyclines by type 1(++--) and type 2(+++ or ++$\pm$-) micro-bial growth Inhibition In EEC 4-plate method were 100% and 71%, respectively. 3. Of 17 positive samples, 6 were positive for tetracyclines, 4 were positive for tetracyclines and sulfonamides, 1 was positive for sulfonamides, and 2 were positive for others by Charm II test. 4. The best eluents were 0.01M methanolic oxalic acid, and the ideal temperature for stable concentration was $40^{\circ}C$ as optimal HPLC analytical conditions for the detection of tetracy-clines. 5. Of the 10 positive samples for tetracyclines by Charm II test, tetracyclines were confirmed in 2 beef and 6 pork samples, using HPLC, at levels ranging from 3.64~4.22 ppm and 0.2~1.20 ppm, respectively.

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Modelling of Differentiated Bandwidth Requests in IEEE 802.16m Systems

  • Yoon, Kang Jin;Kim, Ronny Yongho;Kim, Young Yong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.7 no.4
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    • pp.726-747
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    • 2013
  • In order to support a large number of mobile stations (MSs) with statistical multiplexing in cellular networks, a random access scheme is widely used for uplink (UL) bandwidth request (BR). In the design of a random access based BR scheme, there are two important requirements: short connection delay and diverse Quality of Services (QoSs) support. Such requirements are crucial for IMT-Advanced systems like IEEE 802.16m to provide various types of fourth generation (4G) data services. IEEE 802.16m provides advanced UL BR schemes for non-real time polling service (nrtPS) and best-effort (BE) service to meet the requirements of short connection time and multiple QoS level support. In order to provide short connection time and multiple QoS support, three-step and differentiated BR procedures are adopted. In this paper, a novel modelling of IEEE 802.16m contention based BR scheme is proposed that uses a 2-dimensional discrete time Markov chain. Both the short access delay three-step BR procedures and normal five-step BR procedure are considered in the model. Our proposed model also incorporates the IEEE 802.16m differentiated BR procedure. With the proposed model, we extensively evaluate the performance of IEEE 802.16m BR for two different service classes by changing QoS parameters, such as backoff window size and BR timer. Computer simulations are performed to corroborate the accuracy of the proposed model for various operation scenarios. With the proposed model, accurate QoS parameter values can be derived for the IEEE 802.16m contention-based BR scheme.

Differentiated Lambda Establishment and Wavelength Assignment based on DMS model for QoS guarantees in DWDM Next Generation Internet Backbone Networks (DWDM 차세대 인터넷 백본망에서 DMS 모델 기반의 차등화된 파장할당 및 LSP 설정)

  • Kim, Sung-Un;Lee, Jun-Won
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.9B
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    • pp.760-773
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    • 2003
  • The Internet is evolving from best-effort service toward an integrated or differentiated service framework with quality-of-service (QoS) assurances that are required for new multimedia service applications. Given this increasing demand for high bandwidth Internet with QoS assurances in the coming years, an IP/MPLS-based control plane combined. with a wavelength-routed dense-wavelength division multiplexing (DWDM) optical network is seen as a very promising approach for the realization of future re-configurable transport networks. This paper proposes a differentiated lambda establishment process for QoS guarantees based on the differentiated MPLS service (DMS) model. According to the QoS characteristics of wavelength in optical links and the type of used Optical Cross-Connect (OXC) nodes in DWDM next generation optical Internet backbone network, a differentiated wavelength assignment strategy that considers QoS recovery capability is also suggested.

Design and Implementation of Network-Adaptive High Definition MPEG-2 Streaming employing frame-based Prioritized Packetization (프레임 기반의 우선순위화를 적용한 네트워크 적응형 HD MPEG-2 스트리밍의 설계 및 구현)

  • Park SangHoon;Lee Sensjoo;Kim JongWon;Kim WooSuk
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.10A
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    • pp.886-895
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    • 2005
  • As the networked media technology have been grown in recent, there have been many research works to deliver high-quality video such as HDV and HDTV over the Internet. To realize high-quality media service over the Internet, however, the network adaptive streaming scheme is required to adopt to the dynamic fluctuation of underlying networks. In this paper, we design and implement the network-adaptive HD(high definition) MPEG-2 streaming system employing the frame-based prioritized packetization. Delivered video is inputted from the JVC HDV camera to the streaming sewer in real-time. It has a bit-rate of 19.2 Mbps and is multiplexed to the MPEG-2 TS (MPEG-2 MP@HL). For the monitoring of network status, the packet loss rate and the average jitter are measured by using parsing of RTP packet header in the streaming client and they are sent to the streaming server periodically The network adaptation manager in the streaming server estimates the current network status from feedback packets and adaptively adjusts the sending rate by frame dropping. For this, we propose the real-time parsing and the frame-based prioritized packetization of the TS packet. The proposed system is implemented in software and evaluated over the LAN testbed. The experimental results show that the proposed system can enhance the end-to-end QoS of HD video streaming over the best-effort network.