• 제목/요약/키워드: latency (L)

검색결과 120건 처리시간 0.02초

P2P 기반 Interactive VOD를 위한 레벨 그룹 스트리밍 기법 (A Level Group Streaming Technique for Interactive VOD based on P2P)

  • 김종경
    • 한국통신학회논문지
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    • 제33권11C호
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    • pp.955-962
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    • 2008
  • 멀티캐스트 기법은 큰 규모의 팽 서비스에서 비용을 줄이기 위한 방법 중에 하나다. 그러나 멀티캐스트 시스템에서 한정된 서버와 네트워크의 대역폭을 고려하여 VCR 기능을 구현하는 것은 복잡한 문제들을 내포하고 있어 이에 대한 해법이 필요하다. 따라서 본 연구는 P2Patching을 개선한 논문으로 P2P 환경에서 레벨 그룹을 구성하여 이종 대역폭을 가진 피어들 간에 협력하여 VCR 기능을 지원하는 레벨그룹 스트리밍 기법(LGST : Level Group Streaming Technique)을 제안한다. 이 기법은 서버의 수용성을 향상시키고 네트워크의 대역폭을 효율적으로 사용할 수 있다. 그리고 본 제안 기법의 평가를 위하여 P2Patching과 비교하여 스트림 전송 토플러지 성능 및 스트리밍 질을 실험하였다. 이 실험은 서비스 요청 거부율과 대역폭 감소에 따른 서비스 질에 대한 평가에서는 본 LGST가 P2Patching보다 $11{\sim}18%$ 정도의 성능 향상을 보여주었고, 결함확률에 따른 복원지연 실험과 VCR 기능 수행 주기에 따른 영향에서는 미세한 수치에서의 성능 향상을 보여 주었다.

Analgesic and anti-inflammatory activity of a polyherbal formulation (PHFAROGH)

  • Mohan, M;Gulecha, VS;Aurangabadkar, VM;Balaraman, R;Austin, A;Thirugnanasampathan, S
    • Advances in Traditional Medicine
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    • 제9권3호
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    • pp.232-237
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    • 2009
  • The effect of arogh, a polyherbal formulation-PHF [each 3 g powder contained Nelumbo nucifera G. (0.24 g), Hemidesmus indicus R. (0.24 g), Zingiber officinale R. (0.24 g), Terminalia chebula R. (0.24 g), Quercus infectoria O. (0.12 g), Hibiscus rosa-sinensis L. (0.24 g), Rosa damascene M.(0.24 g), Eclipta alba H.(0.24 g), Glycyrrhiza glabra L. (0.24 g)] was investigated in various experimental models of pain and inflammation. Analgesic activity of PHF was studied in mice using acetic acid induced writhing, tail immersion and hot plate methods. Anti-inflammatory activity of PHF was studied in rats using carrageenan induced hind paw edema and formalin induced rat paw edema methods. PHF significantly (P < 0.05) reduced the number of writhings, increased latency to flick tail in tail immersion method and elevated the mean basal reaction time in hot plate method. PHF significantly (P < 0.05) inhibited carrageenan induced hind paw edema and formalin induced rat paw edema. The PHF was tested at dose of 30, 100, 300 and 500 mg/kg.

Extension of ReInForM Protocol for (m,k)-firm Real-time Streams in Wireless Sensor Networks

  • Li, Bijun;Kim, Ki-Il
    • Journal of information and communication convergence engineering
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    • 제10권3호
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    • pp.231-236
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    • 2012
  • For real-time wireless sensor network applications, it is essential to provide different levels of quality of service (QoS) such as reliability, low latency, and fault-tolerant traffic control. To meet these requirements, an (m,k)-firm based real-time routing protocol has been proposed in our prior work, including a novel local transmission status indicator called local DBP (L_DBP). In this paper, a fault recovery scheme for (m,k)-firm real-time streams is proposed to improve the performance of our prior work, by contributing a delay-aware forwarding candidates selection algorithm for providing restricted redundancy of packets on multipath with bounded delay in case of transmission failure. Each node can utilize the evaluated stream DBP (G_DBP) and L_DBP values as well as the deadline information of packets to dynamically define the forwarding candidate set. Simulation results show that for real-time service, it is possible to achieve both reliability and timeliness in the fault recovery process, which consequently avoids dynamic failure and guarantees meeting the end-to-end QoS requirement.

공복혈당수치와 운동유발전위의 상관관계에 대한 후향적 분석 : 중추운동신경과 말초운동신경의 비교 (A Retrospective Study on the Correlation between Fasting Blood Sugar and Motor Evoked Potentials : Comparison between Central and Peripheral Motor Nerve)

  • 나병조;박성욱;정우상;문상관;박정미;고창남;조기호;김영석;배형섭;홍진우
    • 대한한방내과학회지
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    • 제28권3호
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    • pp.434-441
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    • 2007
  • Objectives : Peripheral neurodegeneration occurs in diabetes mellitus (DM), both sensory and motor nerve. but we don't know exactly if DM affects central nerve pathway for all studies. Electrophysiologic study is one of the most important diagnostic tools for diabetic neuropathy. Electroneurography and electromyography are usually used. but evoked potentials (EP) is more sensitive to small nerve fiber damages and useful for central nerve evaluation in addition to peripheral nerves. Most diabetic neuropathy studies by EP have been performed with somatosensory evoked potentials (SSEP). In contrast, the objective of this study is to investigate if DM targets central motor neurons by assessing the relation between fasting blood sugar (FBS) and motor evoked potentials (MEP) latency. Methods : We inspected the medical records of 34 patients who had MEP tests during admitting days. The latency from cervical portion to abductor pollicis brevis was used as peripheral motor conduction time (PMCT). and the latency from vertex to cervical portion was used as central motor conduction time (CMCT). Then, they were correlated to FBS using correlation analysis. Results : There was a significant linear relation between FBS and PMCT (Pearson's correlation coefficient r=0.487, p<0.01), but a poor linear relation between FBS and CMCT (Pearson's correlation coefficient r=-0.l97. p>0.05). Conclusions : This study suggests that prolonged latencies of MEP in DM may be due to peripheral neuropathy rather than dysfunction of central motor pathway. therefore the clinical use of MEP to diabetic neuropathy has to be divided segmentally.

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곤달비 메탄올 추출물의 진통 효과 (Anti-nociceptive Activity of Methanol Extracts from Ligularia stenocephala)

  • 차동석;전훈
    • 생약학회지
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    • 제44권1호
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    • pp.70-74
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    • 2013
  • Ligularia stenocephala has been widely used as a traditional medicine for the treatment of lots of diseases such as asthma, arthritis, and jaundice. In this study, we evaluated the anti-nocicepitve activities of methanolic extract of L. stenocephala (MLS) using various pain models including thermal nociception as well as chemical nociception methods. MLS showed significant increase in latency time in the tail immersion test and hot-plate test. In addition, the number of acetic acid-induced abdominal constrictions was decreased by MLS. MLS also attenuated paw licking time in the formalin test. The combination test using naloxone revealed that the anti-nociceptive properties of MLS was not associated with opioid receptor activation. The present results demonstrate that MLS may possibly used as valuable analgesic agent for the treatment of nociceptive pain.

펜타조신의 진통작용 및 내성형성에 미치는 인삼 사포닌의 효과 (Effects of Ginseng Total Saponins on the Analgesia and Tolerance Development of Pentazocine)

  • Kim, Hack-Seang;Ann, Sun-Hee;Seong, Yeon-Hee;Kim, Sun-Hye;Oh, Ki-Wan
    • Journal of Ginseng Research
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    • 제16권2호
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    • pp.93-98
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    • 1992
  • This study examined the Influence of ginseng total saponins (GTS) on the analgestic action and tolerance development of pentazocine in mice. Pentazocine prolonged the latency to response in the tail flick rather than in the tail pinch test. The analgesic effect of pentaEocine was antagonized by naloxone and completely eliminated by pretreatment u·ith f-chlorophenylalanine (PCPA). GTS provented the pentasocine-incuced analgesia ann inhibited the development of tolerance to pentazocine. The antagonistic effect of GTS on the pentazocine-induced analgesia was abolished by 5-HTP, but not by L-DOPA. These results suggest that GTS inhibits the analgesic action of pentazocine by the interaction with serotonergic neuron.

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An Advanced Resource Allocation Algorithm for PON-LTE Converged Networks

  • Abhishek Gaur;Vibhakar Shrimali
    • International Journal of Computer Science & Network Security
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    • 제23권7호
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    • pp.16-22
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    • 2023
  • Enhanced radio access technologies (RAT) are deployed in Next Generation Convergence Networks by the service providers so as to satisfy the basic requirements of end-users for e.g. QoS. Whenever the available resources are being shared simultaneously and dynamically by multiple users or distribution of allocated channels randomly, the deficiency of spectral resources and dynamic behavior of Network traffic in real time Networking, we may have problem. In order to evaluate the performance of our proposed algorithm, computer simulation has been performed on NS-2 simulator and a comparison with the existing algorithms has been made.

비휘발성 메모리 시스템을 위한 저전력 연쇄 캐시 구조 및 최적화된 캐시 교체 정책에 대한 연구 (A Study on Design and Cache Replacement Policy for Cascaded Cache Based on Non-Volatile Memories)

  • 최주희
    • 반도체디스플레이기술학회지
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    • 제22권3호
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    • pp.106-111
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    • 2023
  • The importance of load-to-use latency has been highlighted as state-of-the-art computing cores adopt deep pipelines and high clock frequencies. The cascaded cache was recently proposed to reduce the access cycle of the L1 cache by utilizing differences in latencies among banks of the cache structure. However, this study assumes the cache is comprised of SRAM, making it unsuitable for direct application to non-volatile memory-based systems. This paper proposes a novel mechanism and structure for lowering dynamic energy consumption. It inserts monitoring logic to keep track of swap operations and write counts. If the ratio of swap operations to total write counts surpasses a set threshold, the cache controller skips the swap of cache blocks, which leads to reducing write operations. To validate this approach, experiments are conducted on the non-volatile memory-based cascaded cache. The results show a reduction in write operations by an average of 16.7% with a negligible increase in latencies.

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모바일 인터넷 환경에서 신호세기 예측을 이용한 PFMIPv6의 성능 개선 (Performance Improvement of PFMIPv6 Using Signal Strength Prediction in Mobile Internet Environment)

  • 이준희;김현우;최용훈;박수원;이승형
    • 한국정보과학회논문지:정보통신
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    • 제37권4호
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    • pp.284-293
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    • 2010
  • 모바일 인터넷 환경에서 단말의 끊김 없는 서비스 제공을 위해 고속 핸드오버 기술이 필수적이다. 현재까지 다양한 핸드오버 기술들이 제안되었으며, Fast handover for Proxy Mobile IPv6(PFMIPv6)가 고속 핸드오버에 적용될 수 있는 유력한 기술이다. 본 논문에서는 PFMIPv6 기술이 모바일 와이맥스와 같은 무선 인터넷 환경에 효과적으로 적용될 수 있도록 예측 모델을 적용한 L2-L3 핸드오버의 크로스 레이어 기법을 제안하였다. 제안한 핸드오버 기법의 검증을 위해 맨하탄 모델, 고속도로 모델, 개방 모델의 세 가지 이동 환경을 고려하였으며, 각 환경에서 predictive-mode 동작 성공 확률, 핸드오버 지연시간, 패킷 손실량, 시그널링 비용에 대해서 비교 분석하였다. 성능 분석을 통해 제안한 방식이 PFMIPv6와 비교하여 더 우수한 성능을 나타냄을 확인하였다

IP 이동성 지원 프로토콜에 대한 비교 연구: Fast Handover 대 Mobile IPv6 (A Comparative Study of IP Mobility Protocols : Fast Handover vs. Mobile IPv6)

  • 백상헌;최양희
    • 한국통신학회논문지
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    • 제29권6A호
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    • pp.651-659
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    • 2004
  • Fast Handover[1] 프로토콜은 핸드오프 과정에서 발생하는 지연 시간을 줄임으로써 끊김없는 핸드오프가 가능하도록 해준다. 핸드오프 지연시간을 줄이기 위해서 Fast Handover는 링크 계층의 트리거 정보를 이용한 예측 기법을 사용한다. 따라서 기존 Mobile IPv6에 비해서 더 많은 시그널링 비용을 초래한다. 뿐만 아니라 가변적인 특성을 가지는 링크 특성으로 인해 예측한 정보가 정확하지 않을 수도 있고 이 경우에는 불필요한 버퍼 공간을 낭비하게 된다. 따라서, 이러한 부가적인 비용을 고려하여 Fast Handover와 Mobile IPv6의 성능을 비교, 평가하는 것이 필요하다. 본 논문에서는 두 프로토콜에서의 시그널링 비용과 패킷 전송 비용을 모델링하여 링크 계층 트리거의 시점이 전체 비용에 미치는 영향과 핸드오프 과정에서의 버퍼 요구량을 비교하였다. 그 결과 최적화된 핸드오프 성능을 위해서 트리거 시점을 적합하게 설정하는 것이 중요하다는 것을 알 수 있었다.