• Title/Summary/Keyword: latency (L)

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Experimental Study on the Influence of the Function of Spleen on Learning and Memory (비기능이 학습과 기억에 미치는 영향에 대한 실험적 연구)

  • 박찬원;이진우;채한;홍무창;신민규
    • The Journal of Korean Medicine
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    • v.20 no.4
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    • pp.39-49
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    • 2000
  • This study was conducted to prove that there exists a relation between the spleen and learning and memory as Oriental medicine believesTo promote the function of the Spleen, Guibitang was administered to rats in this study. Rats were 250~300g Sprague-Dawley, and were divided into three groups. One was the normal group without any pretreatment. Another was the control group which was administered normal saline and the abdominal injection of L-NAME before learning and memory test. And the 3rd was the sample group, to which was administered Guibitang extract and (no 'the') abdominal injection of L-NAME before the learning and memory test. Each group was made up of 12 rats. Morris water maze and radial arm maze tasks were performed in the learning test and Morris water maze task in the memory test. For 2 days to evaluate the ability of learning in the Morris water maze, 16 trials were carried out and first latency(lapse time to find the escape platform for the first time) was measured. The next day, to evaluate the ability of memory, the escape platform was eliminated from the maze, and total path, target entry number, first latency and memory score were measured. 48hrs before the radial arm maze task was performed, bait was deprived from each group. After learning test, bait was permitted to each group. So 85% of the body weight was maintained for 6 days of the test. Each of the eight arms was baited; correct choice numer and error were counted; each trial was finished when the rat had entered each of the eight arms, or more than 10 minutes had elapsed. The results were as follows: In the learning test, the first latency of the sample group in the Morris water maze showed evident improvement of learning compared to control group at the 11th, 12th, 13th trial of 16 trials, and correct choice number in radial arm maze showed noticeable improvement compared to the control group at 3rd, 4th and 5th; In the memory test, the memory score of the sample group showed evident improvement compared to the control group. From the above results, the administration of Guibitang, which tonifies the function of the Spleen, could enhance the ability of learning and memory. So it was suggested that the Spleen has a relation with learning and memory.

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The Mechanism of Proxy Mobile IPv4 to Minimize the Latency of Handover Using MIH Services (MIH 서비스를 활용한 Proxy Mobile IPv4의 핸드오버 지연 최소화 방안)

  • Kim, Sung-Jin;You, Heung-Ryeol;Rhee, Seuck-Ho
    • 한국정보통신설비학회:학술대회논문집
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    • 2008.08a
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    • pp.211-217
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    • 2008
  • Recently, there are many efforts to support seamless mobility in 802.11 WLANs using IP Layer mobility protocols. The IP layer mobility protocols are the most efficient mechanism to guarantee the service session continuity when IP subnet is changed during handover. Even if the IP layer mobility protocols are quite efficient, the feature of the protocols that had been designed to consider only L3 layer makes it difficult to improve the performance of hand over more and more. Nowadays, to overcome this limitation of IP mobility protocols, many researchers have worked on the mobility protocols integration of different layers (e.g., L2 layer). In this paper, we propose the enhanced Proxy MIPv4 to minimize the latency of handover using MIH protocol in 802.11 WLANs. The proposed mechanism minimizes the latency of authentication by exchanging security keys between Access Routers during handover. Moreover, it also minimizes packet losses by Inter-AP Tunneling and data forwarding.

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New Two-Level L1 Data Cache Bypassing Technique for High Performance GPUs

  • Kim, Gwang Bok;Kim, Cheol Hong
    • Journal of Information Processing Systems
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    • v.17 no.1
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    • pp.51-62
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    • 2021
  • On-chip caches of graphics processing units (GPUs) have contributed to improved GPU performance by reducing long memory access latency. However, cache efficiency remains low despite the facts that recent GPUs have considerably mitigated the bottleneck problem of L1 data cache. Although the cache miss rate is a reasonable metric for cache efficiency, it is not necessarily proportional to GPU performance. In this study, we introduce a second key determinant to overcome the problem of predicting the performance gains from L1 data cache based on the assumption that miss rate only is not accurate. The proposed technique estimates the benefits of the cache by measuring the balance between cache efficiency and throughput. The throughput of the cache is predicted based on the warp occupancy information in the warp pool. Then, the warp occupancy is used for a second bypass phase when workloads show an ambiguous miss rate. In our proposed architecture, the L1 data cache is turned off for a long period when the warp occupancy is not high. Our two-level bypassing technique can be applied to recent GPU models and improves the performance by 6% on average compared to the architecture without bypassing. Moreover, it outperforms the conventional bottleneck-based bypassing techniques.

The Effects of Korean Ginseng on Memory Loss in a Rat Models (Scopolamine 유도 치매동물모델에서 고려인삼(백삼, 홍삼 및 흑삼)의 기억력 개선 효과)

  • Kang, Shin-Jyung;Woo, Jeong-Hwa;Kim, Ae-Jung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.8
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    • pp.1190-1196
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    • 2013
  • The purpose of this study was to investigate the mechanism and effects of different types of ginseng on memory improvement in an experimental rat model. In this study, SD rats were induced for memory deficits through scopolamine treatment (1 mg/kg, i.p.) then administrated with ginseng extract for 7 weeks. The rats were divided into five groups: saline (1 mL/kg, NC: negative control), white ginseng (300 mg/kg, WG), red ginseng (300 mg/kg, RG), black ginseng (300 mg/kg, BG), and scopolamine (1 mg/kg, PC: positive control). The step through latency of the BG and RG groups was significantly longer than the PC group in the retention trial of multiple trial passive avoidance test. In the spatial reference memory triads of the Morris water maze test, the latency time of BG and RG was significantly lower than the PC group. In addition, in the prove test, the time spent in the platform quadrant of BG and RG groups were significantly longer than the PC group. Brain choline acetyltransferase (ChAT) activities BG and RG groups significantly increased compared to other groups. On the other hand, the levels of malondialdehyde (MDA) were significantly lower in the BG and RG groups compared to other groups. These result suggested that black ginseng could be useful to enhance learning memory and cognitive function by regulation of cholinergic enzymes.

Electromyographic Study of Lumbosacral Radiculopathy by Lumbar Disc (요추 추간원판에 의한 요천추 선경근 병변의 근전도 연구)

  • Kim Ho-Bong;Lee Jin-Hee;Kim Jong-Youl;Bae Sung-Soo
    • The Journal of Korean Physical Therapy
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    • v.11 no.3
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    • pp.1-12
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    • 1999
  • The aim of this study is to examine the sensitivity and characteristics of electromyography abnormalities detected by using various paramenters in patients with lumbosacral radiculopathies. EMG is widely used for disgnosing and localizing the level of radiculopathy. The results of the study were as follow : 1. In electromyography, L5 radiculopathy usa 95 cases(51.690). S1 radiculopathy was $45m(24.5\%)$ L4 radiculopathy was 18cases $(9.8\%)$, and L2, 3 radiculopathy was 8cases$(4.3\%)$. Remains 18cases$(9.8\%)$ had no definite radiculopathy. 2. Peroneal and tibial motor nerve conduction velocity studies were not significant as compared to the side to side. 3. Latency of H-reflex in L5 radiculopathy was $30.55\pm2.47$ in affected side, $29.47\pm2.29$ in unaffected side, in S1 radiculopathy was $33.00\pm2.03$ in affected side, R30.18\pm2.21$ in unaffected side. It was statistically significant(p<0.01). H-reflex mean difference of S1 radiculopathy group was significantly prolonged as compared to the L5 and S1 radiculopathies(p<0.001). 4. In L2, 3 radiculopathy, abnormal spontaneous activities and motor unit action potentials were showed high sensitivity in upper lumber paraspinal, hip adductors, quadriceps and iliopsoas muscles. 5. In L4 radiculopathy, lower lumbar paraspinal, tibialis anterior, quadriceps muscles were showed high sensitivity. 6. In L5 radiculopathy, lower lumbar paraspinal, extensor hallucis longus, extensor digitorum longus, peroneus longus, extensor digitorum brevis, gluteus maximus, tensor fasciae latae muscles were showed high sensitivity. 7. In S1 radiculopathy, lower lumbar paraspinal, gluteus maximus, peroneus longus, soleus, abductor hallucis, hamstrings, extensor digitorum brevis, extensor hallucis lognus, gastrocnemius muscles were showed high sensitivity.

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Design of Dual-Path Decimal Floating-Point Adder (이중 경로 십진 부동소수점 가산기 설계)

  • Lee, Chang-Ho;Kim, Ji-Won;Hwang, In-Guk;Choi, Sang-Bang
    • Journal of the Institute of Electronics and Information Engineers
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    • v.49 no.9
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    • pp.183-195
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    • 2012
  • We propose a variable-latency Decimal Floating Point(DFP) adder which adopts the dual data path scheme. It is to speed addition and subtraction of operand that has identical exponents. The proposed DFP adder makes use of L. K. Wang's operand alignment algorithm, but operates through high speed data-path in guaranteed accuracy range. Synthesis results show that the area of the proposed DFP adder is increased by 8.26% compared to the L. K. Wang's DFP adder, though critical path delay is reduced by 10.54%. It also operates at 13.65% reduced path than critical path in case of an operation which has two DFP operands with identical exponents. We prove that the proposed DFP adder shows higher efficiency than L. K. Wang's DFP adder when the ratio of identical exponents is larger than 2%.

Analysis on the GPU Performance according to Hierarchical Memory Organization (계층적 메모리 구성에 따른 GPU 성능 분석)

  • Choi, Hongjun;Kim, Jongmyon;Kim, Cheolhong
    • The Journal of the Korea Contents Association
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    • v.14 no.3
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    • pp.22-32
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    • 2014
  • Recently, GPGPU has been widely used for general-purpose processing as well as graphics processing by providing optimized hardware for parallel processing. Memory system has big effects on the performance of parallel processing units such as GPU. In the GPU, hierarchical memory architecture is implemented for high memory bandwidth. Moreover, both memory address coalescing and memory request merging techniques are widely used. This paper analyzes the GPU performance according to various memory organizations. According to our simulation results, GPU performance improves by 15.5%, 21.5%, 25.5%, 30.9% as adding 8KB L1, 16KB L1, 32KB L1, 64KB L1 cache, respectively, compared to case without L1 cache. However, experimental results show that some benchmarks decrease performance since memory transaction increases due to data dependency. Moreover, average memory access latency is increased as the depth of hierarchical cache level increases when cache miss occurs significantly.

QoS Guaranteed Fast Handoff Algorithm for Wireless LAN (무선 랜 환경에서의 QoS 보장형 고속 핸드오프 알고리듬)

  • 신일희;이채우
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.40 no.12
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    • pp.59-70
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    • 2003
  • Proposed CCRSVP (Candidate Casting RSVP) algorithm is a new fast handoff method which uses advanced multicasting method and RSVP for IEEE 802.11 Wireless LAN (WLAN) environments. The proposed algorithm shows good performance in the handoff latency and the B/W efficiency aspect and guarantees QoS because it uses L2 information (BSSID) of WLAN and starts to reserve resources and multicast packets before L2 handoff completes. We also propose a Markov chain performance analysis model in which we can analyze the handoff performance of various handoff algorithms. Using the model, we compare bandwidth efficiency of the proposed algorithm with existing handoff algorithms which use RSVP by analyzing blocking probability of session, resource usage, and the average number of ongoing session in a cell. The results show that the proposed algorithm shows better performance than the existing algorithms in the above three performance aspects.

Effects of sleep-inducing juice on sleep quality and heart rate variability in adults with disturbed sleep

  • Kim, Choun-sub;Kim, Maengkyu;Kim, Min-ju;Jung, Hyeyoung
    • Nutrition Research and Practice
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    • v.14 no.6
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    • pp.606-620
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    • 2020
  • BACKGROUND/OBJECTIVES: Although some juices affect subjective sleep quality, there is a lack of information on the effect of a specific juice on objective sleep quality and heart rate variability (HRV) during sleep; thus the present study investigated whether a blended juice made from natural extracts influenced sleep quality and HRV during sleep in adults with disturbed sleep. SUBJECTS/METHODS: A randomized, crossover study was conducted on twenty-five adults (15/10, female/male) complaining of difficulty initiating or maintaining nighttime sleep (Pittsburgh sleep quality index [PSQI] ≥ 5). During feeding sessions (FS), subjects received sleep-inducing juice made of natural ingredients (250 mL/trial) twice a day for 8 weeks or non-FS (N-FS) for 8 weeks while maintaining normal activities. Sleep quality and parameters were recorded via wearable actigraph for 7 consecutive days, and PSQI scores were assessed before and after the intervention. HRV was also monitored at rest and during sleep. RESULTS: After receiving the sleep-inducing juice intervention (FS), PSQI scores were significantly decreased (P < 0.001) and correlated with a significant decline in fatigue severity scale and visual analogue scale levels (P < 0.05; both). HRV indices of vagal activity were significantly improved during FS (P < 0.05), and no significant differences in N-FS were observed. Sleep efficiency and total sleep time increased significantly (P < 0.05) and sleep latency, total counts, sleep fragmentation index, and movement index, decreased significantly (P < 0.05, all 4) during FS, with no significant differences-observed during N-FS. CONCLUSIONS: This study results demonstrated that an 8-week course of sleep-inducing juice has led to improve sleep quality, suggesting an enhanced cardiac vagal tone during sleep. Thus, it could be a well-tolerated option for adults with disturbed sleep.

A Method of Performance Improvement for AAA Authentication using Fast Handoff Scheme in Mobile IPv6 (Mobile IPv6에서 Fast Handoff기법을 이용한 AAA 인증 성능 향상 방안)

  • Kim Changnam;Mun Youngsong;Huh Eui-Nam
    • Journal of KIISE:Information Networking
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    • v.31 no.6
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    • pp.566-572
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    • 2004
  • In this paper, we define the secure authentication model to provide a mobile node with global roaming service and integrate the Fast Handoff scheme with our approach to minimize the service latency. By starting the AAA(Authentication, Authorization and Account) procedure with Fast Handoff simultaneously when a roaming occurs, authentication latency is reduced significantly and provision of fast and seamless service is possible. The previous works such as IPsec(Internet Protocol Security), RR (Return Routability) and AAA define the procedures performed after the completion of Layer2 Handoff which leads us to study a way of providing the real time and QoS guaranteed service during this period. The proposed scheme is for this goal and when appling it to roaming environment it shows the cost reduction up to 55% and 17% for the case of the MN receiving the FBACK and not respectively before L2 Handoff occurs.