• Title/Summary/Keyword: W-ATM

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Implementation of the mobility for Location Searching in Broadband Intelligence Wireless ATM Networks (광대역 지능 무선 ATM 망에서 위치 탐색을 위한 이동성 구현)

  • 정운석;박광채
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.3
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    • pp.461-467
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    • 2003
  • This paper proposes the method of mobility implementation for location searching in the intelligence wireless ATM networks that expand and apply standard broadband signaling capabilities, and analyze the performance based on the numerical algorithm. The existing B-ISDN UNI protocol stack demands the location search mechanism to determine the location of mobile terminal in the wireless ATM networks because it use single protocol through the fixed PTP interface or PTM interface that don't support terminal mobility. The proposed method make possible the dynamic mobility at a part of wireless access by minimizing the signaling load without a falling-off in system performance by using the intelligence network technology according to the expansion of ATM and B-ISDN signaling integration based on the fixed networks. We implemented the performance analysis by MFC modeling based on numerical algorithm, and realized the efficiency of expenses by carrying out the comparative signaling performance evaluation to measure the relative gains of location search service in the intelligence wireless ATM system. The obtained results have the flexibility to operate in the public B-ISDN network environment without a change of existing B-ISDN/ATM NNI signaling reference to support the wireless ATM access system, and can easily expand to correspond to terminal mobility and various multimedia services in the next broadband PCS.

Studies on the Removal of Silica from the Boric Acid Solution by Reverse Osmosis Membrane Process (역삼투막 공정을 이용한 붕산수 중의 실리카 제거에 관한 연구)

  • 구본문;임지원;이태원;박길웅
    • Membrane Journal
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    • v.5 no.4
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    • pp.137-144
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    • 1995
  • This studies concern the separation of aqueous boric acid solution and same solution containing silica using cellulose acetate RO S/W 4040 module manufactured by Hydranautics Co. The operating conditions of the applied pressures, temperatures, and feed flow rate are also investigated to characterize the permeabilities, biroc acid recovery, and silica rejection, so that the optimum operating conditions would be found out. In the case where the operating conditions are the temperature 35$^{\circ}$C, The pressure 20atm, and the feed flow rate 2.82 l/min, for the boric acid aqueous solution, the boric acid recovery 58.7% and the permeation rate 2.82 l/min were obtained. And also the results showed the boric acid recovery 68.1% and the permeation rate 1.56 l/min at the operating conditions, 35$^{\circ}$C and 10atm. For the boric acid solution containing silica, when the feed solution are at the conditions of 35$^{\circ}$C and 3.2atm, the boric acid recovery 69.7%, the silica rejection 97.5% and the permeation rate 0.47 l/min were obtained. And the operating conditions were at 35$^{\circ}$C, 20atm and the feed flow rate 2.92 l/min, the results showed the boric acid recovery 56.4%, the silica rejection 96.1% and the permeation rate 2.72 l/min.

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A Queueing Model with Loss and Time Priority for Optimal Buffer Control in ATM (손실 우선과 시간 우선이 공존하는 ATM에서의 최적 버퍼 제어를 위한 대기 행렬 모형)

  • Lee, H.W.;Kim, E.Y.
    • Journal of Korean Institute of Industrial Engineers
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    • v.25 no.1
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    • pp.130-140
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    • 1999
  • This paper deals with a priority queueing model in an ATM system. Two types of customers are considered. Type-1 customers have push-put priority over type-2 customers. Type-1 customers can enter the service only when the number of type-2 customers is less than a threshold T. We derive the joint probability of the number of customers in the buffer, the mean waiting time, and the loss probabilities of each type. We also propose an optimal control policy that satisfies a given quality of service.

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A Study on Ozone Generation Characteristic using Ba-Ti-Si Ceramic Tube (Ba-Ti-Si 세라믹 방전관의 오존 발생 특성 연구)

  • 이동훈;박홍재;박재윤
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.7
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    • pp.634-640
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    • 2003
  • This paper is to be researched into ozone generation character of Bi-Ti-Si type high dielectric yield ceramic catalyst discharge tube. And conditions of basic experiment are the outside diameter of discharge tube : 52 mm, the length of discharge tube : 350 mm, the frequence : 900 Hz, the temperature of cooling water : 25 $^{\circ}C$, quantity of flow : 5, 10, 20 l/min, pressure : 1.2, 1.4, 1.6 atm, and distance of discharge gap : 0.4, 0.6, 0.8 mm. Ozone generation characteristics were measured to consumption power. At quantity of flow : 20 l/min, discharge gap : 0.6 mm, pressure : 1.6, and consumption power : 150 W, Maximum ozone generation efficiency of 175 g/kWh was obtained. Maximum ozone generation efficiency was measured below the flow quantity of 20 l/min at below pressure of 1.6 atm. However, Maximum ozone generation efficiency was measured over the flow quantity of 20 l/min at over pressure of 1.6 atm.

A Study on Clock Recovery Algorithm for ATM AAL 1 (ATM AAL 1을 위한 클럭 복원 알고리즘 연구)

  • Jeong, Y.K.;Lee, W.T.;Lee, J.J.;Park, Y.H.;Kim, K.H.;Kim, H.K.
    • Proceedings of the KIEE Conference
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    • 1999.07g
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    • pp.3196-3198
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    • 1999
  • In this paper, we are proposed ATM AAL 1 source clock recovery methods for CBR service. The proposed method compute the difference between network clock level and the reference level by inspecting the variation of a buffer. Also it is the service clock recovery method that control local clock using the look-up table defined clock dividing rate of the difference in advance. It can be applicable to both SDH network and PDH network which has no common reference clock between its ends, it has an important mean in view of the internetworking between existing networks for the integrated service chased by B_ISDN.

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Development of an external twin-fluid nozzle for Selective Catalytic Reduction (선택적 촉매 환원법을 위한 외부 혼합형 이유체 노즐 개발에 대한 실험적 연구)

  • Park, J.K.;Lee, C.W.
    • Journal of ILASS-Korea
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    • v.9 no.2
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    • pp.24-33
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    • 2004
  • The effect of the working fluid flow conditions and nozzle geometry on the spray performance of a twin-fluid nozzle used in Selective Catalytic Reduction is investigated experimentally. The liquid pressure is varied in the range of 0.3atm to 1.5atm and the air pressure is varied from the 0.5atm to 3.0atm. relative position between liquid nozzle(internal nozzle) and air nozzle(external nozzle) tip changes front 1mm inside the air nozzle to 1mm outside the air nozzle. The orifice diameter of the air nozzle is varied with 5mm. 6mm and 7mm. Spray visualization is realized with CCD-Camera. SMD(Sauter Mean Diameter) and mean particle velocities are measured by PDPA(Phase Doppler Particle Analyzer) under various experimental conditions. The measuring point is 300mm away from the nozzle tip in the downstream spray. The experimental results are that spray angle is depended air flow rate because nozzle diameter, air pressure and nozzle tip relative positions are related air flow rate. SMD is depended air flow rate and water flow rate. Also, SMD is increased when water flow rate is bigger. SMD is decreased when Air flow rate is bigger.

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Design of a Digital Burst MODEM for High-Speed ATM Satellite Communications Part I : Analysis of Synchronization Techniques (고속 ATM 위성통신을 위한 TDMA 버스트 모뎀 설계 1부 : 수신기 동기기술 분석)

  • Hwang, Sung-Hyun;Kim, Ki-Yun;Choi, Hyung-Jin
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.10
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    • pp.34-41
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    • 1998
  • In this paper, we evaluate synchronization techniques suitable for high-speed ATM satellite communications with a transmission rate of 155Mbit/s, and propose optimal algorithms that improve the tracking performance, where QPSK is selected for a modulation scheme, and the receiver is operated in burst mode. Based on these asumptions, we proposed modified algorithms and architectures for automatic frequency control(AFC), carrier recovery(CR), and symbol timing recovery(STR) for burst acquisition. Analysis is performed under AWGN environments with respect to the number of required symbol, steady-state stability, and hardware implementation for the proposed algorithms.

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In Vitro and In Vivo Anti-Oxidative and Anti-Inflammatory Activities of Acer tegmentosum Maxim Extracts (RAW 264.7 대식세포와 염증유도 동물모델에서 산겨릅나무 추출물의 항산화 및 항염증 효과)

  • Lee, Cho-Eun;Jeong, Hyeon-Hee;Cho, Jin-Ah;Ly, Sun Yung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.1
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    • pp.1-9
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    • 2017
  • Acer tegmentosum Maxim (ATM) is known as traditional medicine for treatment of hepatic disorders such as hepatitis, related-inflammatory disease, and hepatic cancer. In this study, we evaluated the antioxidant and anti-inflammatory effects of ATM extracted with $80^{\circ}C$ water or 95% ethanol. Antioxidant activities of ATM extracts were measured based on DPPH and ABTS radical scavenging activities, total polyphenolic compound contents, and ferric reducing antioxidant power. The anti-inflammatory effects of ATM extract were assayed on release of nitric oxide, tumor necrosis factor $(TNF)-{\alpha}$, and interferon $(IFN)-{\gamma}$ from lipopolysaccharide (LPS)-induced macrophages. In these experiments, 95% ethanol extract of ATM showed stronger antioxidant and anti-inflammatory effects than water extract. Therefore, we determined the effects of ATM ethanol extract on an animal model of sepsis. Seven days oral gavage of ATM ethanol extract followed by LPS stimulation reduced the protein levels of $TNF-{\alpha}$ and $IFN-{\gamma}$ in serum as well as mRNA levels of $TNF-{\alpha}$ and interleukin-6 in intestinal epithelial cells. In addition, ATM ethanol extract reduced DNA damage in mouse lymphocytes. These results indicate that ATM extract has strong antioxidant and anti-inflammatory in vitro and in vivo effects and may be developed as a potential food material for prevention of inflammatory diseases.

System Development of a 100 kW Molten Carbonate Fuel Cell III (System Control and Operation Mode) (100 kW급 용융탄산염 연료전지 시스템 개발 III (시스템 제어 및 운전모드))

  • Lim, Hee-Chun;Ahn, Kyo-Sang;Seo, Hai-Kyung;Eom, Yeong-Chang
    • Proceedings of the KIEE Conference
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    • 2003.07b
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    • pp.1350-1352
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    • 2003
  • For developing a 100 kW MCFC power generation system, Several design parameters for a fuel cell stack and system analysis results by Cycle Tempo, a processing computer soft ware, were described. Approximately two substacks with 90 cells are required to generate 100 kW at a current density of $125\;mA/cm^2$ with $6000\;cm^2$ of cells. An overall heat balance was calculated to predict exit temperature. The 100 kW power is expected only under pressurized operation condition at 3 atm. Recycle of cathode gas by more than 50% is recommended to run the stack at $125\;mA/cm^2$ and 3 atm. Manifolds should be designed based on gas flow rates for the suggested operating condition. The fuel cell power generation system was designed conceptually with several choices of utilization of anode exhaust gas. To operate and evaluate the MCFC system, control and measurement system and operation mode are designed before 100 MCFC system construction. In system control schematics, OS, PLC and MMI were consisted and have roles for MCFC system control. For operation of 100 kW MCFC system, NS, PS PR mode were considerated step by step and simulated.

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Ionic Hydrogenation of Carbonyl Groups With Molybdenum and Tungsten Complexes (몰리브덴과 텅스텐 착물을 이용한 카르보닐기의 이온성 수소화 반응)

  • Song Jeong-Sup
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.7 no.4
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    • pp.715-720
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    • 2006
  • Metalhydrides such as $Cp(CO)_{2}(L)MH$ (L = t-butylisocyanide and 2,6-dimethylphenylisocyanide M = Mo and W) have been synthesized and used for ionic hydrogenation of the carbonyl groups in the presence of triflic acid. When these complexes have also used as catalyst precursors for hydrogenation of 3-pentanone under mild conditions ($23^{\circ}C,\;<4.1\;atm H_{2}$). The turnover rates were very slow, with the fastest initial rate of about 2 turnovers per 1 day for the [$Cp(CO)_{2}(ArNC)Mo][BA_{r}^{F}_{4}$] system.

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