• Title/Summary/Keyword: Intermediate support

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A Novel Scheme for an RSVP Session Handoff in Wireless IP Networks with Micro-Mobility (Micro-Mobility 환경에서의 RSVP Session Handoff를 위한 연구)

  • Kim, Jeong-Hoe;Min, Sang-Won
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.4B
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    • pp.199-206
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    • 2008
  • In this paper, we propose a novel Route_Reconf message as the RSVP message to maintain an RSVP session for hard handoff and consider path-comparing route (PCR) a PCR algorithm to find an intermediate node in the charge of downlink re-establishment. And, we consider information form each mode for the PCR algorithm, which also reduces the frequency and amount of exchanged RSVP message to minimize packet loss and delay between an intermediate node and a receiver. According to the proposed algorithm, a new support node (NSN) and an existing support node (ESN) along the RSVP path can be found; the former is a supporting RSVP session node newly searched and the latter is the last supporting node holding the previous session after handoff. On receiving the Route_Reconf message at the ESN, a new allocated route from a NSN to the MN waiting for the handoff via a new AR is configured by the ESN.

Preparation and Gas Permeation Properties of Silica Membranes on Porous Stainless Steel-Tube Supports (다공성 금속 지지체에 제조된 실리카 분리막의 기체 투과 특성)

  • Lee, Hye Ryeon;Seo, Bongkuk
    • Membrane Journal
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    • v.24 no.3
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    • pp.177-184
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    • 2014
  • Silica membranes with high permeability were prepared using colloidal and polymeric silica sols on a porous stainless steel-tube support by a DRFF and SRFF method. Silica sols were derived with tetraethylorthosilicate (TEOS) by sol-gel method and analyzed with DLS, FE-SEM, and $N_2$ adsorption. The coating of the intermediate layer with colloidal silica sol on the stainless steel-tube support led to a denser surface morphology of the membrane along with a considerable reduction in the number of surface defect. As the polymeric silica sol enclosed the colloidal silica sol with spherical particles during the SRFF method, the separation-layer-coated silica membrane showed a denser surface than the intermediate layer. Moreover, the silica membranes showed high hydrogen gas permeability of $(6.63-9.21){\times}10^{-5}mol{\cdot}m^{-2}{\cdot}s^{-1}{\cdot}Pa^{-1}$ with low $H_2/N_2$ perm-selectivity (2.9-3.1) at room temperatures.

Preparation of Asymmetric Ceramic Membrane by Coating-Pyrolysis Process (도포-열분해법을 이용한 비대칭 세라믹 분리막 제조)

  • Ryu, Hyun-Wook;Kim, Byung-Hoon
    • Journal of the Korean Ceramic Society
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    • v.39 no.12
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    • pp.1153-1157
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    • 2002
  • The fabrication of a three-layered asymmetric ceramic membrane was performed by slip casting of the porous alumina support and dip coating of the alumina intermediate layer using high purity ${\alpha}-Al_2O_3$ powders that have different particle size, followed by screen printing-pyrolysis of the $Tio_2$ layer as an ultrafilteration membrane using Ti-naphthenate solution. The bending strength, porosity and mean pore size of the alumina support were 231 kg/$cm^2$s, 30.26% and 0.19 ${mu}m$, respectively. The thickness of the intermediate layer was 30 ${mu}m$ and the mean pore size of that was 0.063 ${mu}m$. Also, the top layer was 0.5 ${mu}m$ thick and micropores with about 20 nm size were formed uniformly.

A Study on the Technology Commercialization Process and Performance of Public Research Institutes in Korea using the Structural Equation Model (구조방정식 모형을 이용한 공공연구기관의 기술사업화 프로세스와 성과분석)

  • Kim, Byung-Keun;Cho, Hyun-Jung;Og, Joo-Young
    • Journal of Korea Technology Innovation Society
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    • v.14 no.3
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    • pp.552-577
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    • 2011
  • We have analyzed technology transfer and commercialization process and factors affecting the outcomes of technology commercialization of public research institutes in Korea. A technology commercialization process model was presented as an input, intermediate outcomes/capabilities, output (outcome) structure using the structural equation model. Input variables include R&D input, technology commercialization strategy/support, collaboration, social capital. The model also includes R&D capabilities and technology commercialization performance as intermediate variable and output variable respectively. The technology commercialization performance was measured as the number of technology transfer and spin-off. We conducted survey and 88 institutes responded. Empirical results show that R&D input influence R&D capabilities and R&D capabilities influence the output of technology transfer and commercialization. Collaboration activities and social capital also appear to have a positive effect on the output. However, the effect of strategy and support on the output appear to be not statistically significant.

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A Novel Scheme for an RSVP Session Handoff in Wireless IP Networks with Micro-Mobility (Micro-Mobility 환경에서의 RSVP Session Handoff를 위한 연구)

  • Kim, Jeong-Hoe;Min, Sang-Won
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.5B
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    • pp.296-303
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    • 2008
  • In this paper, we propose a novel Route_Reconf message as the RSVP message to maintain an RSVP session for hard handoff and consider a path-comparing route(PCR) algorithm to find an intermediate node in the charge of down-link re-establishment. And, we consider information form each mode for the PCR algorithm, which also reduces the frequency and amount of exchanged RSVP message to minimize packet loss and delay between an intermediate node and a receiver. According to the proposed algorithm, a new support node(NSN) and an existing support node(ESN) along the RSVP path can be found; the former is a supporting RSVP session node newly searched and the latter is the last supporting node holding the previous session after handoff. On receiving the Route_Reconf message at the ESN, a new allocated route from a NSN to the MN waiting for the handoff via a new access router is configured by the ESN.

A Qualitative Study on Responsible Tour Operators' Perception and Operation Status (공정관광 운영자의 인식과 공정관광 운영 현황 분석 - 심층면접을 통한 영역분석을 중심으로 -)

  • Kim, Kyung-Hee;Kang, Sung-Jin
    • Journal of Agricultural Extension & Community Development
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    • v.22 no.1
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    • pp.15-24
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    • 2015
  • Responsible tourism attracting worldwide attention has supported local economy and community development as a type of alternative tourism. This study explored the perception toward fairness in tourism and operation status of responsible tour operators in South Korea by conducting in-depth interviews with probe questions. Ten responsible tour operators were interviewed with a semi-structured interview questionnaire for one upto two hours. From the interview data, six themes were identified as difficulties of responsible tour operators: lack of manpower, advertising and promotion, absence of marketing strategy, regulation, lack of budget and lack of recognition of responsible tourism. As government support identified through the interviews, there are the followings seven themes: a low entry barrier market, investment in human resources, resource utilization, community-based policies, connection with local produce, community support and connection system of responsible travel agencies with intermediate support organizations at a local level, The findings of this paper implicate the underlying subject of responsible tourism from a tour operators' perspective.

Dynamic Stability of Elastically Restrained Cantilever Pipe Conveying Fluid with Crack (크랙을 가진 탄성지지된 유체유동 외팔파이프의 동적 안정성)

  • Son, In-Soo;Yoon, Han-Ik
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.2
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    • pp.177-184
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    • 2008
  • The dynamic stability of elastically restrained cantilever pipe conveying fluid with crack is investigated in this paper. The pipe, which is fixed at one end, is assumed to rest on an intermediate spring support. Based on the Euler-Bernoulli beam theory, the equation of motion is derived by the energy expressions using extended Hamilton's Principle. The crack section is represented by a local flexibility matrix connecting two undamaged pipe segments. The influence of a crack severity and position, mass ratio and the velocity of fluid flow on the stability of a cantilever pipe by the numerical method are studied. Also, the critical flow velocity for the flutter and divergence due to variation in the support location and the stiffness of the spring support is presented. The stability maps of the pipe system are obtained as a function of mass ratios and effect of crack.

Fabrication of Porous Reaction Bonded Silicon Carbide with Multi-Layered Pore Structures (다층 기공구조를 갖는 다공성 반응소결 탄화규소 다공체 제조)

  • Cho, Gyoung-Sun;Kim, Gyu-Mi;Park, Sang-Whan
    • Journal of the Korean Ceramic Society
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    • v.46 no.5
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    • pp.534-539
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    • 2009
  • Reaction Bonded Silicon Carbide(RBSC) has been used for engineering ceramics due to low-temperature fabrication and near-net shape products with excellent structural properties such as thermal shock resistance, corrosion resistance and mechanical strength. Recently, attempts have been made to develop hot gas filter with gradient pore structure by RBSC to overcome weakness of commercial clay-bonded SiC filter such as low fracture toughness and low reliability. In this study a fabrication process of porous RBSC with multi-layer pore structure with gradient pore size was developed. The support layer of the RBSC with multi-layer pore structure was fabricated by conventional Si infiltration process. The intermediate and filter layers consisted of phenolic resin and fine SiC powder were prepared by dip-coating of the support RBSC in slurry of SiC and phenol resin. The temperature of $1550^{\circ}C$ to make Si left in RBSC support layer infiltrate into dip-coated layer to produce SiC by reacting with pyro-carbon from phenol resin.

P2P System for Simultaneous Support of Menu and Social Network Joint Buying Information (메뉴와 소셜 네트워크 공동구매 정보 동시제공 P2P 시스템)

  • Kim, Boon-Hee
    • The Journal of the Korea institute of electronic communication sciences
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    • v.6 no.3
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    • pp.445-449
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    • 2011
  • A P2P technique is the concept to share sources efficiently in distributed environment that is studying a lot. In these P2P systems, the server to support the contents-information have less overloads than the composed system as the server to have resources generally. In this paper, we suggest a P2P system to support conveniences for users that were connected with the information of joint-buying based on social network. The joint-buying information based on social network is supported by peers using a p2p system and these information to intermediate are supported by a P2P server.

Study of buckling stability of cracked plates under uniaxial compression using singular FEM

  • Saberi, Sina;Memarzadeh, Parham;Zirakian, Tadeh
    • Structural Engineering and Mechanics
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    • v.69 no.4
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    • pp.417-426
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    • 2019
  • Buckling is one of the major causes of failure in thin-walled plate members and the presence of cracks with different lengths and locations in such structures may adversely affect this phenomenon. This study focuses on the buckling stability assessment of centrally and non-centrally cracked plates with small-, intermediate-, and large-size cracks, and different aspect ratios as well as support conditions, subjected to uniaxial compression. To this end, numerical models of the cracked plates were created through singular finite element method using a computational code developed in MATLAB. Eigen-buckling analyses were also performed to study the stability behavior of the plates. The numerical results and findings of this research demonstrate the effectiveness of the crack length and location on the buckling capacity of thin plates; however, the degree of efficacy of these parameters in plates with various aspect ratios and support conditions is found to be significantly different. Overall, careful consideration of the aspect ratio, support conditions, and crack parameters in buckling analysis of plates is crucial for efficient stability design and successful application of such thin-walled members.