• Title/Summary/Keyword: End-to-end reliability

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A Study on Advertising Effect according to Involvement, Advertising Location and Advertising Forms - Focusing on the Fashion Internet Search Advertising - (관여, 광고위치, 광고형태에 따른 광고효과 연구 - 패션 인터넷 검색광고를 중심으로 -)

  • Je, Eun-Suk
    • The Research Journal of the Costume Culture
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    • v.20 no.2
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    • pp.251-262
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    • 2012
  • This research aimed to examine an advertising location according to consumer involvement about internet search advertising and advertising effect according to advertising forms. This research carried out a questionnaire survey from May 25, 2011 for seven days with the target of men and women at the age of 20s-30s who tried search advertising in Seoul and capital area, and 519 copies were used for final analysis. For analysis of collected materials, the reliability test, factor analysis, $t$-test, regression analysis and ${\chi}^2$ test were executed by using statistical package SPSS 16.0. The results are as follows. First, it appeared that consumer's clothing involvement, advertising involvement, advertising location and advertising forms had an influence on site attitude and clicking intention. Consumers of high clothing involvement, high advertising involvement and upper end advertising appeared to have high site attitude and clicking intention. Second, all consumers of the low and high clothing involvement and upper end advertising appeared to prefer the upper end advertising. It appeared that consumers of low advertising involvement prefer lower end advertising, and consumers of high advertising involvement prefer the upper end advertising at an advertising location according to clothing involvement. Accordingly, it is important that the search advertising exposes advertising in the upper end, and that should use an advertising phrase capable of giving trust to consumers. As the text advertising had high site attitude and clicking intention in the advertising forms, consumers should pay attention to the advertising phrase.

A Study on TCP Performance Enhancements in Wireless Networks (무선망에서의 TCP 성능 향상 방안에 관한 연구)

  • Park, Do-Yong;Kim, Young-Beom
    • Journal of IKEEE
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    • v.10 no.1 s.18
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    • pp.30-39
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    • 2006
  • The TCP protocol can provide some reliability using sliding window mechanism for data transmission, flow control, and congestion control. However, TCP has some limitations in that it has basically been designed solely for wired communication environments. If traditional TCP protocol is used also in wireless networks, the end-to-end data transmission performance degrades dramatically due to frequent packet losses caused by transmission errors and hand-offs. While there have been some research efforts on TCP enhancements considering the mobility of wireless communication devices, in this paper we propose a new method to improve the TCP performance by combining the Snoop and the Freeze-TCP methods. In the proposed scheme, the TCP end-to-end semantics is maintained and no changes of existing protocols in sending systems or in routers are required. It has the advantage of simple implementation because TCP code changes are limited to mobile devices for applying the Freeze-TCP and it requires only to add Snoop modules in base stations. Accordingly, the proposed scheme can operate well in the existing networks. Finally, in this study, we compared the performance of the proposed scheme with traditional TCP, other approaches through simulations using ns-2.

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A Routing Protocol with Fast-Recovery of Failures Using Backup Paths on MANETs (MANET에서 백업경로를 이용한 빠른 경로복구 능력을 가진 라우팅 프로토콜)

  • Thai, Ahn Tran;Kim, Myung-Kyun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.7
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    • pp.1541-1548
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    • 2012
  • This paper proposes a new multipath-based routing protocol on MANETs with Fast-Recovery of failures. The proposed protocol establishes the primary and secondary paths between a source and a destination considering the end-to-end packet reception reliability of routes. The primary path is used to transmit messages, and the secondary path is used to recover the path when detecting failures on the primary path. If a node detects a link failure during message transmission, it can recover the path locally by switching from the primary to the secondary path. By allowing the intermediate nodes to recover locally the route failure, the proposed protocol can reduce the number of packet loss and the amount of control packets for setting up new paths. The simulation result using QualNet simulator shows that the proposed protocol was about 10-20% higher than other protocols in terms of end-to-end message delivery ratio and the fault recovery time in case of link fault was about 3 times faster than the other protocols.

Design of the Brake Device Using the Axial Crushing of Truncated Cone Type Cylinder

  • Kim, Ji-Chul;Shim, Woo-Jeon
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2002.10b
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    • pp.387-388
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    • 2002
  • A Brake device for the high-speed impacting object is designed using an axial crushing of thin-walled metal cylinder, Thickness of the cylinder is increased smoothly from the impacting end to the fixed end, resulting in the truncated cone shape. Truncated cone shape ensures that plastic hinges are formed sequentially from impacting end. This increases the reliability of brake device working. Computational and real experiments were performed to verify the effects of conical angle. Results indicate that undesirable sudden rise of crushing load can be prevented by applying appropriate conical angle.

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Delay Analysis of Selective Repeat ARQ for a Markovian Source Over a Wireless Channel (무선 채널에서의 Selective Repeat ARQ 프로토콜의 Delay 성능 분석)

  • Kim Jeong Geun;Kim Young Soo;Lee Kyesan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.11B
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    • pp.930-937
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    • 2004
  • In this paper, we analyze the delay performance for a Markovian source transported over a wireless channel with time-varying error characteristics. To improve the reliability of the channel, the end points of the wireless link implement a selective-repeat (SR) ARQ error control protocol. We provide an approximate discrete-time analysis of the end-to-end mean packet delay, which consists of transport and resequencing delays. Numerical results and simulations indicate that our approximate analysis is sufficiently accurate for a wide range of parameter values.

Fault Location Algorithm in a Two-ended Sources Transmission Line (양전원 송전선로의 고장점 표정 알고리즘)

  • Park, Chul-Won
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.65 no.1
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    • pp.18-24
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    • 2016
  • In order to service restoration and enhance power system reliability, a number of impedance based fault location algorithms have been developed for fault locating in a transmission line. This paper presents an advanced impedance-based fault location algorithms in a two-ended sources transmission line to reduce the DC offset error effects. This fault location algorithm uses of the GPS time synchronized voltage and current signals from the local and remote terminal. The algorithm uses an advanced DC offset removal filter. A series of test results using ATPdraw simulation data show the performance effectiveness of the proposed algorithm. The proposed algorithm is valid for a two-end sources transmission network.

A Survey of QoS Based Routing Protocols for Wireless Sensor Networks

  • Sumathi, R.;Srinivas, M.G.
    • Journal of Information Processing Systems
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    • v.8 no.4
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    • pp.589-602
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    • 2012
  • With the increasing demand for real time applications in the Wireless Senor Network (WSN), real time critical events anticipate an efficient quality-of-service (QoS) based routing for data delivery from the network infrastructure. Designing such QoS based routing protocol to meet the reliability and delay guarantee of critical events while preserving the energy efficiency is a challenging task. Considerable research has been focused on developing robust energy efficient QoS based routing protocols. In this paper, we present the state of the research by summarizing the work on QoS based routing protocols that has already been published and by highlighting the QoS issues that are being addressed. The performance comparison of QoS based routing protocols such as SAR, MMSPEED, MCMP, MCBR, and EQSR has also been analyzed using ns-2 for various parameters.

Behavior of Surface Flashover Depending on Shape and Gap Distance of End Shield in Vacuum Interrupter (진공인터럽터 내부 End Shield형상과 갭거리에 따른 연면방전거동)

  • Yoon, Jae-Hun;Lim, Kee-Jo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.23 no.2
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    • pp.169-173
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    • 2010
  • Because of power consumption increase, global warming, and limitation of installation, not only high reliability and interruption capability but also compact and light power apparatuses are needed. In this paper, E field calculation and experiment were processed to identify the influence of the shape of end shield and gap distance. It is expected that the results of FEM simulation and experiments could be the basic data to develop VI. the results of FEM simulation and experiments are as following. Firstly, maximum E fields were compared by means of finite element method as a function of the shape of end shield. 3 types of models were used to analyze maximum E field of each model and the influence of shape of shield could be identified. As a result, proposed L type shield could reduce the maximum E field by 20%. Secondly, the influence of the gap distance between end shields on E field was analyzed. As the gap distance become short the gap distance between inner walls of ceramic also become short. And the maximum E field concentrated on inner wall of ceramic finally increased. Thirdly, the experiment was conducted by fabricating each prototype. As a result, no creepage occurred in shieldless model. In other words, creepage occurred in the shield-installed models. And creepage inception voltages were different from each other because of the difference of maximum E field. Fourthly, The equation that shows relation between calculated E field and measured creepage inception voltage was proposed as a result of FEM analysis and experiment. It is concluded that when designing VI this equation could be important data to reduce time and cost by identifying indirectly the optimal gap distance and the shape of shield required to prevent creepage.

Development and Evaluation of Shared Medical Decision-Making Scale for End-of-Life Patients in Korea (한국형 공유 의료적 의사 결정 측정도구 개발 및 평가)

  • Jo, Kae-Hwa
    • Journal of Korean Academy of Nursing
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    • v.42 no.4
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    • pp.453-465
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    • 2012
  • Purpose: The study was done to develop a shared decision-making scale for end-of-life patients in Korea. Methods: The process included construction of a conceptual framework, generation of initial items, verification of content validity, selection of secondary items, preliminary study, and extraction of final items. The participants were 388 adults who lived in one of 3 Korean metropolitan cities: Seoul, Daegu, or Busan. Item analysis, factor analysis, criterion related validity, and internal consistency were used to analyze the data. Data collection was done from July to October 2011. Results: Thirty-four items were selected for the final scale, and categorized into 7 factors explaining 61.9% of the total variance. The factors were labeled as sharing information (9 items), constructing system (7 items), explanation as a duty (5 items), autonomy (4 items), capturing time (3 items), participation of family (3 items), and human respect (3 items). The scores for the scale were significantly correlated among shared decision-making scale, terminating life support scale, and dignified dying scale. Cronbach's alpha coefficient for the 34 items was .94. Conclusion: The above findings indicate that the shared decision-making scale has a good validity and reliability when used for end-of-life patients in Korea.

Design of a Secure Web-mail System based on End-to-End (End-to-End 기반의 안전한 웹 메일 시스템 설계)

  • 전철우;이종후;이상호
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.13 no.2
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    • pp.13-29
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    • 2003
  • Web-mail system is worthy of note as a next generation e-mail system for its mobility and easiness. But many web-mail system does not have any kind of security mechanism. Even if web-mail system provides security services, its degree of strength is too low. Using these web-mail systems, the e-mail is tabbed, modified or forged by attacker easily. To solve these problems, we design and implement secure web-mail system based on the international e-mail security standard S/MIME in this thesis. This secure web-mail system is composed of server system and client system The server system performs basic mail functions - sending/receiving the mails, storing the mails, and management of user information, etc. And the client system performs cryptographic functions - encryption/decryption of the mails, digital signing and validation, etc. Because client system performs cryptographic functions this secure web-mail system gives its reliability and safety, and provides end-to-end security between mail users. Also, this secure web-mail system increase system efficiency by minimize server load.