• Title/Summary/Keyword: Dama

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Modification of SBR Latex and its Adhesion Characteristic (SBR Latex의 개질 및 접착특성)

  • Kim, Goo-Ni;Chun, Yong-Chul;Oh, Sang-Taek;Park, Seung-Hyeun;Lee, Chang-Ho;Yoo, Chong-Sun;Min, Byung-Kwon
    • Elastomers and Composites
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    • v.29 no.5
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    • pp.444-452
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    • 1994
  • Emulsion graft copolymerizations of vinyl monomers, butyl acrylate(BA), methyl methacrylate(MMA), 2-ethylhexyl acrylate (EHA), glycidyl methacrylate (GMA), 2-hydroxyethyl methacrylate(HEMA), methacrylonitrile(MAN), dimethylaminoethyl methacrylate(DAMA) or 2-vinyl pyridine(VP), onto carboxyl-terminated SBR latex were carried out under different experimental conditions. In case of synthesizing SBR-g-poly(butyl acrylate), the degree of grafting was increased with increasing the amount of emulsifier, polymerization temperature and the amount of initiator. Pull-out strength of resorcinol-formaldehyde-latex(RFL) adhesives formulated with modified latexes was very higher than that of RFL adhesive formulated with ungrafted latex. When the modified latexes with GMA, HEMA, MAN, DAMA or VP were used, the break occurred at cords. Peel strength of RFL adhesives formulated with SBR-g-poly(GMA), SBR-g-poly(HEMA) or SBR-g-poly(VP) was higher by about 1.3 times than that of RFL adhesives formulated with unmodified SBR against nylon cord and was higher by about 2.0 times against polyester cord.

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Design and Implementation of Real-Time Satellite Communication Network Management System (실시간 위성통신망 관리 시스템의 설계 및 구현)

  • Kim, Sin-Hong;Chae, Yi-Geun
    • The Transactions of the Korea Information Processing Society
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    • v.3 no.5
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    • pp.1198-1206
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    • 1996
  • This paper proposes the functionality of communication network management which operates in central control station of satellite communication network, which will be constructed to DAMA-SCPC ground station using KORE ASAT. And communication network configuration components are classified with hierarchical structure in order to efficiently maintain communication network operation management, and configuration components that are classified into graphic objects and this graphic objects are visualized with tree structure which can be handled uniformally and efficiently. In addition to that, this paper proposes expression method of graphic object to implement our real time communication network management system, and the real time communication net-work management composed as client-server system. The performance of the proposed algorithm is analyzed through the computer simulation.

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Predicting Feed Intake of Fallow Deer (Dama Dama) Using Alkanes as a Marker

  • Ru, Y.J.;Miao, Z.H.;Glatz, P.C.;Choct, M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.2
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    • pp.209-212
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    • 2002
  • The understanding of seasonal forage intake of grazing deer is essential for the development of supplementary feeding strategies in southern Australia. The alkane technique is used in other animal species for estimating feed intake of individual animals and their diet composition. To assess the potential of using alkanes as a marker for predicting feed intake of fallow deer, the daily faecal recovery of alkanes and excretion rate of dosed artificial alkanes (C32 and C36) were measured with 6 deer fed three forage based diets. The artificial alkane capsule designed for use in sheep is suitable for fallow deer. Faecal samples need to be collected over days 7-19 after dosing. The daily excretion rate was 40 mg for C32 and 37 mg for C36. The faecal recovery of natural alkanes is incomplete and the faecal concentrations of alkanes need to be adjusted for an accurate estimation of intake. The actual feed intake of 6 experimental deer over a 5 day period was accurately estimated ($R^2$=0.52) using alkanes.

A Time Slot Assignment Algorithm Based on Transmission Interval in Time Division Multiple Access Communication System (시분할 다중접속 통신시스템에서 전송주기를 고려한 시간슬롯 할당 알고리즘)

  • Lee, Ju-Hyung;Cho, Joon-Young;Park, Kyung-Mi;Lee, Seung-Chan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.3B
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    • pp.181-188
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    • 2012
  • In this paper, the time slot assignment algorithm, which is based on various transmission interval in TDMA DAMA communication system, has been proposed. The performance of the proposed algorithm and the random assignment algorithm is compared through computer simulations. The simulation results show that the new algorithm can enhance the efficiency of time slot usage much more than the random assignment algorithm. Especially, the lower the congestion of the network is, the higher the efficiency of time slot usage for short transmission interval is.

Performance on Channel Multiple Access for the OBP Satellite (OBP(On-Board Processing)위성의 채널 다중 접속 방식에 대한 성능 연구)

  • 이정렬;김덕년
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2000.12a
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    • pp.5-8
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    • 2000
  • In this paper, The new scheme for Demand Assigned Multiple Access(DAMA) system is proposed. To focus on the onboard processor's specific monitoring of output port of the downlink, we found the Throughput and Blocking probability by the request traffic(λ) and channel's departure probability(Ρ).

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Adaptive Control Technique for the Random Access Channel in DVB-RCS2 based Next Generation Military Satellite Networks (DVB-RCS2 기반 차세대 군 위성 네트워크 랜덤 액세스 채널 적응형 제어 기법)

  • Lee, WonKyun;Jang, Dae-Hee;Chung, Jong-Moon
    • Journal of Internet Computing and Services
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    • v.21 no.2
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    • pp.99-108
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    • 2020
  • In this paper, we analyze the most suitable RA method among PAMA, DAMA, and RA classified by the multiple access method of satellite communication in the rapidly changing traffic environment according to the emergency and tactical situation. It suggests an alternative to improve the limit of output degradation. Based on the CRDSA protocol selected as the standard of DVB-RCS2 among the current satellite communication methods, CRDSA2R (Contention) maintains an optimal RA channel environment by checking the limitations in an environment where packet volume is rapidly increasing and observing channel load and channel conditions. We propose a Resolution Diversity Slotted ALOHA with Adaptive Random Access.

DEER FARMING IN KOREA : ON-FARM SURVEY IN KYUNG-KEE AND CHUNG-BUK PROVINCES

  • Kwak, W.S.;Kim, K.H.;Kim, C.W.;Jeon, B.T.;Lee, S.M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.7 no.3
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    • pp.347-355
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    • 1994
  • Thirty farmers, representing three major deer counties in Kyung-Kee province and 50 farmers scattered in Chung-Buk province were interviewed to determine the current status of the Korean deer industry. Items surveyed were general information, farmed deer breeds. farm facilities, feeding and nutrition, hygiene and disorder incidence, velvetting, income sources, products and their sale, management problems and herd size control. The 888 deer farmed in Kyung-Kee province included spotted deer (Cervus nippon. 69.4%), red deer (Cervus elaphus, 6.1%), wapiti (Cervus elaphus canadensis, 12.2%), spotted $\times$ red deer hybrids (6.2%), red deer $\times$ wapiti hybrids (4.6%). and fallow deer (Dama dama, 1.5%). Poor information on feeding was evidenced by wide variation among farms of daily feed supply and ratios of forage to concentrate, and poor nutritional considerations according to physiological status of deer. Hygiene needed more attention. The incidence of diseases and disorders was high: enteritis (73.3% in Kyung-Kee province), fractures (60.0%), and dystocia (56.7%). The major source of farm income was velvet antler and its blood. To improve productive efficiency, attention should be given to improving farm facilities, simplified product marketing, developing standard feeding system, and economic grazing system.

D-ARP Scheme for Full Mesh Routing in Partial BMA Network (제한적 BMA 네트워크에서 Full Mesh 라우팅을 위한 D-ARP 기법)

  • Kim, Moon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.25 no.8
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    • pp.1088-1094
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    • 2021
  • This paper proposes a partial BMA (Broadcasting Multiple Access) network structure and D-ARP (Distributed Address Resolution Protocol) method in order to support full mesh routing function in the DAMA (Demand Assigned Multiple Access)-based MF-TDMA (Multi Frequency-Time Division Multiple Access) satellite system. The partial BMA network enables legacy router devices and routing protocols to be adopted in the satellite communication system, and decreases the amount of routing protocol overhead. In addition, we introduce the D-ARP method that help a spoke satellite node acquiring the MAC (Media Access Control) address from remote satellite nodes in none BMA satellite network. The D-ARP method provides the MAC address of remote nodes to each other nodes through the broadcasting-enabled satellite channel. And we lastly evaluate and analysis the network performance of the proposed approach.

Performance on the Beam-Switched Demand Assigned Multiple Access for the Packet Satellite Communication (패킷 위성통신의 빔스위칭 요구할당 다중 접속 방식에 대한 성능 연구)

  • 김덕년;김재명
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.10
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    • pp.1462-1470
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    • 1989
  • This paper aims at investigating the Demand Assigned Multiple Access(DAMA) system for the packet-switched Satellite Communication. An onboard processor of the multisport beam satellite incorporates the ground controller to macimize the packet transmissions for each slot. 'Request Following' trnasmission mode is introduced as a transmission strategy of ground station under the control of its zone controller. The combined scheme of reservation channel access and contention channel access was proposed by Lee & Mark[3] for improving the Delay-Throughput performance. Our scheme provides less communication delay of approximately max. 200msec for achieving the corresponding throughput than the Lee & Mark's work does. Delay versus Throughput curves as well as Delay versus Traffic parameter curves are obtained. Numerical results obtained through the analysis and by the computer simulation show that the proposed scheme provides the low average packer delay even under the condition that the number of transponders (M)is below the half of the number of zones(N).

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