RED-DTB: A Dual Token Bucket Based Queue Management Algorithm

Improving the Quality of Service (QoS) of Internet traffic is widely recognized as a critical issue for the next-generation networks. In this paper, we present a new algorithm for the active queue management, namely RED-DTB. This buffer control technique is used to enforce approximate fairness among a large number of concurrent Internet flows. Like RED (Random Early Detection) algorithm, the RED-DTB mechanism can be deployed to actively respond to the gateway congestion, keep the gateway in a healthy state, and protect the fragile flows from being stolen bandwidth by greedy ones. The algorithm is based on the so-called Dual Token Bucket (DTB) pattern. That is, on the one hand, every flow is rate-limited by its own token bucket, to ensure that it can not consume more than its fair share of bandwidth; On the other hand, to make some compensations to less aggressive flows, such as connections with larger round trip time or smaller sending window, and to gain a relatively higher system utilization coefficient, all flows, depending on their individual behavior, may have a chance to fetch tokens from the public token bucket when they run out of their own share of tokens. The algorithm is analyzed and evaluated by simulations, and is proved to be effective in protecting the gateway buffer and controlling the fair allocation of bandwidth among flows.

Observation on efficacy of treating vascular dementia gait disorder with electro-acupuncture(EA) on Jiājǐ(夹脊 EX-B2) along lumbar vertebra combined with scalp acupuncture

Objective To observe the efficacy of treating vascular dementia gait disorder with electroacupuncture （EA） on Jiaji （夹脊EX-B2） along the lumbar vertebra combined with scalp acupuncture, in order to explore a more effective therapeutic method. Methods Forty-two patients were divided into an acupuncture group and a drug group according to the method of random number table, with 21 cases in each group. EA on EX-B2 from L2 to L5 （bilateral） and scalp acupuncture on Baihui （百会 CV 20） and Sishencong （四神聪EX-HN 1） were applied in the acupuncture group, once a day the course of treatment was 30 days; Duxil was taken orally by the drug group, one pill twice a day for 30 days as a course of treatment. After treatment was completed, the efficacy was evaluated and activities of daily living （ADL） were compared between the two groups. Results The total effectiveness rate for the acupuncture group was 90.5%, which was significantly better than that of the drug group （61.9%）, and the differences were statistically significant （P〈0.05）; ADL was compared before and after treatment, and the differences were statistically significant （the acupuncture group： 24.52±9.34 vs 32.85±13.56; the drug group： 25.47±10.04 vs 29.99±13.87, both P〈0.01）; after treatment, ADL, including gait disorders, in the acupuncture group was more significantly improved than that of the drug group, and the differences were statistically significant （32.85±13.56 vs 29.99± 13.87, P〈0.01）. Conclusion The efficacy of treating vascular dementia gait disorder with electro-acupuncture （EA） on EX-B2 along lumbar vertebra combined with scalp acupuncture was superior to orally administered Duxil.