期刊文献+
共找到40篇文章
< 1 2 >
每页显示 20 50 100
Research on Applications of Humanism Management Thoughts and Positive Incentive on Contemporary Enterprise Management Activities
1
作者 Gefei Sun 《International Journal of Technology Management》 2015年第10期117-119,共3页
In this paper, we conduct research on the applications of humanism management thoughts and positive incentive on contemporary enterprise management activities. The success or failure of an enterprise, it has connected... In this paper, we conduct research on the applications of humanism management thoughts and positive incentive on contemporary enterprise management activities. The success or failure of an enterprise, it has connected with the enterprise staff. Modem enterprise to make the enterprise in the competitive market of the brand is enduring, its survival is to be active play to the initiative, enthusiasm and creativity of employees, emphasizing the subject status of the employees and the leading role which is to emphasize the importance of basic management in enterprise management. Our research provides managers with the state-of-the-art methodology of management which will enhance the overall performance and the efficiency of business operating. 展开更多
关键词 Humanism management Positive Incentive Enterprise management activities.
下载PDF
The diameter of beech snags is an important factor for saproxylic beetle richness: Implications for forest management and conservation 被引量:1
2
作者 Václav Zumr Oto Nakládal +1 位作者 Lukás Bílek JiríRemes 《Forest Ecosystems》 SCIE CSCD 2023年第5期635-645,共11页
Snags are an important component of beech forests that promote biodiversity.However,their occurrence is completely marginal in managed stands.Creating snags in these stands would greatly enhance biodiversity.We invest... Snags are an important component of beech forests that promote biodiversity.However,their occurrence is completely marginal in managed stands.Creating snags in these stands would greatly enhance biodiversity.We investigated whether snag dimensions were important for saproxylic beetle richness since they were easily transferable parameters to forest management and assessed the presence of other snag microhabitats affecting beetle communities.Data collection was performed using passive flight traps placed on thirty snags in a recent beech reserve.A total of 6706 adults belonging to 231 saproxylic species(53 Red List species,23%)were captured.The results showed that the most important snag parameters were the diameter(thickness)and canopy openness of the surrounding stands.The occurrence of Fomes fomentarius,the volume of snag and decay class 3 were marginally significant in terms of the preference of all saproxylic species.Alpha diversity was reduced by an advanced degree of decay and a surprisingly deep stem cavity.After dividing snag thickness into categories(<35 cm;35–70 cm and>70 cm DBH),we found that categories with snag diameter greater than 35 cm showed little differences in all saproxylic and Red List species richness and diversity indices and exhibited the highest similarity in beetle communities.Regarding recommendations to forest managers in terms of optimization and simplification of practical procedures,we suggest actively creating high stumps to act as snags greater than 35 cm in DBH diameter to promote biodiversity in beech management stands. 展开更多
关键词 DEADWOOD Coleoptera Biodiversity Active management Endangered beetles
下载PDF
A Fully Adaptive Active Queue Management Method for Congestion Prevention at the Router Buffer
3
作者 Ali Alshahrani Ahmad Adel Abu-Shareha +1 位作者 Qusai Y.Shambour Basil Al-Kasasbeh 《Computers, Materials & Continua》 SCIE EI 2023年第11期1679-1698,共20页
Active queue management(AQM)methods manage the queued packets at the router buffer,prevent buffer congestion,and stabilize the network performance.The bursty nature of the traffic passing by the network routers and th... Active queue management(AQM)methods manage the queued packets at the router buffer,prevent buffer congestion,and stabilize the network performance.The bursty nature of the traffic passing by the network routers and the slake behavior of the existing AQM methods leads to unnecessary packet dropping.This paper proposes a fully adaptive active queue management(AAQM)method to maintain stable network performance,avoid congestion and packet loss,and eliminate unnecessary packet dropping.The proposed AAQM method is based on load and queue length indicators and uses an adaptive mechanism to adjust the dropping probability based on the buffer status.The proposed AAQM method adapts to single and multiclass traffic models.Extensive simulation results over two types of traffic showed that the proposed method achieved the best results compared to the existing methods,including Random Early Detection(RED),BLUE,Effective RED(ERED),Fuzzy RED(FRED),Fuzzy Gentle RED(FGRED),and Fuzzy BLUE(FBLUE).The proposed and compared methods achieved similar results with low or moderate traffic load.However,under high traffic load,the proposed AAQM method achieved the best rate of zero loss,similar to BLUE,compared to 0.01 for RED,0.27 for ERED,0.04 for FRED,0.12 for FGRED,and 0.44 for FBLUE.For throughput,the proposed AAQM method achieved the highest rate of 0.54,surpassing the BLUE method’s throughput of 0.43.For delay,the proposed AAQM method achieved the second-best delay of 28.51,while the BLUE method achieved the best delay of 13.18;however,the BLUE results are insufficient because of the low throughput.Consequently,the proposed AAQM method outperformed the compared methods with its superior throughput and acceptable delay. 展开更多
关键词 Active queue management dropping rate DELAY LOSS performance measures
下载PDF
A FUZZY-LOGIC CONTROL ALGORITHM FOR ACTIVE QUEUE MANAGEMENT IN IP NETWORKS 被引量:10
4
作者 Liu Weiyan Zhang Shunyi +1 位作者 Zhang Mu Liu Tao 《Journal of Electronics(China)》 2008年第1期102-107,共6页
Active Queue Management (AQM) is an active research area in the Internet community. Random Early Detection (RED) is a typical AQM algorithm, but it is known that it is difficult to configure its parameters and its ave... Active Queue Management (AQM) is an active research area in the Internet community. Random Early Detection (RED) is a typical AQM algorithm, but it is known that it is difficult to configure its parameters and its average queue length is closely related to the load level. This paper proposes an effective fuzzy congestion control algorithm based on fuzzy logic which uses the pre- dominance of fuzzy logic to deal with uncertain events. The main advantage of this new congestion control algorithm is that it discards the packet dropping mechanism of RED, and calculates packet loss according to a preconfigured fuzzy logic by using the queue length and the buffer usage ratio. Theo- retical analysis and Network Simulator (NS) simulation results show that the proposed algorithm achieves more throughput and more stable queue length than traditional schemes. It really improves a router's ability in network congestion control in IP network. 展开更多
关键词 Congestion control Fuzzy logic AQM (Active Queue management RED (Random Early Detection) IP network
下载PDF
Active forest management accelerates carbon storage in plantation forests in Lishui,southern China 被引量:3
5
作者 Jiaojiao Diao Jinxun Liu +2 位作者 Zhiliang Zhu Xinyuan Wei Mingshi Li 《Forest Ecosystems》 SCIE CSCD 2022年第1期33-46,共14页
Background:China has committed to achieving peak CO_(2)emissions before 2030 and carbon neutrality before 2060;therefore,accelerated efforts are needed to better understand carbon accounting in industry and energy fie... Background:China has committed to achieving peak CO_(2)emissions before 2030 and carbon neutrality before 2060;therefore,accelerated efforts are needed to better understand carbon accounting in industry and energy fields as well as terrestrial ecosystems.The carbon sink capacity of plantation forests contributes to the mitigation of climate change.Plantation forests throughout the world are intensively managed,and there is an urgent need to evaluate the effects of such management on long-term carbon dynamics.Methods:We assessed the carbon cycling patterns of ecosystems characterized by three typical plantation species(Chinese fir(Cunninghamia lanceolata(Lamb.)Hook.),oak(Cyclobalanopsis glauca(Thunb.)Oerst.),and pine(Pinus massoniana Lamb.))in Lishui,southern China,by using an integrated biosphere simulator(IBIS)tuned with localized parameters.Then,we used the state-and-transition simulation model(STSM)to study the effects of active forest management(AFM)on carbon storage by combining forest disturbance history and carbon cycle regimes.Results:1)The carbon stock of the oak plantation was lower at an early age(<50 years)but higher at an advanced age(>50 years)than that of the Chinese fir and pine plantations.2)The carbon densities of the pine and Chinese fir plantations peaked at 70 years(223.36 Mg⋅ha^(‒1))and 64 years(232.04 Mg⋅ha^(‒1)),respectively,while the carbon density in the oak plantation continued increasing(>100 years).3)From 1989 to 2019,the total carbon pools of the three plantation ecosystems followed an upward trend(an annual increase of 0.16–0.22 Tg C),with the largest proportional increase in the aboveground biomass carbon pool.4)AFM increased the recovery of carbon storage after 1996 and 2009 in the pine and Chinese fir plantations,respectively,but did not result in higher growth in the oak plantation.5)The proposed harvest planning is reasonable and conducive to maximizing the carbon sequestration capacity of the forest.Conclusions:This study provides an example of a carbon cycle coupling model that is potentially suitable for simulating China's plantation forest ecosystems and supporting carbon accounting to monitor peak CO_(2)emissions and reach carbon neutrality. 展开更多
关键词 Active forest management Carbon storage IBIS Plantations STSM
下载PDF
A simulation study of using active traffic management strategies on congested freeways 被引量:3
6
作者 Ramakrishna VADDE Joseph O. SAI +1 位作者 Mohammed A. FARUQI Pat T. LEELANI 《Journal of Modern Transportation》 2012年第3期178-184,共7页
The main objective of this study is to evaluate the effectiveness of using active traffic management (ATM) strategies on freeways in terms of the driver's behavior and operational impacts. A few test beds were sele... The main objective of this study is to evaluate the effectiveness of using active traffic management (ATM) strategies on freeways in terms of the driver's behavior and operational impacts. A few test beds were selected to evaluate the impacts of ATM such as speed harmonization, shoulder utilization, and ramp metering. Test beds used in this study were at places where an ATM is either proposed or previously implemented, i.e., where data exists for condi- tions prior to and after the implementation of ATM. Data collected from the test beds were used in a simulation model to evaluate the impacts of each ATM strategy on speed, travel time, and crash rates. Simulation results indicated that the implementation of speed harmonization on US 90 showed a 14% reduction in crashes and a 2%-3% increase in freeway speed; the implementation of hard shoulders on US 90 showed a 39% increase in travel time, 22% increase in freeway capacity and 60% decrease in delays; and the implementation of ramp metering on US 59 between Bissonnet St. and Fondern road showed a decrease of 23 % in freeway travel time, a 14% increase in freeway speed and 11% decrease in accident rates. 展开更多
关键词 active traffic management VISSIM speed harmonization hard shoulder ramp metering
下载PDF
Active Queue Management Exploiting the Rate Information in TCP-IP Networks 被引量:2
7
作者 Abderrahmane Boudi Malik Loudini 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2018年第1期223-231,共9页
In this paper, we propose a new mechanism called explicit rate notification(ERN) to be used in end-to-end communications. The ERN scheme encodes in the header of transmission control protocol(TCP) packets information ... In this paper, we propose a new mechanism called explicit rate notification(ERN) to be used in end-to-end communications. The ERN scheme encodes in the header of transmission control protocol(TCP) packets information about the sending rate and the round trip time(RTT) of the flows. This new available information to the intermediate nodes(routers) is used to improve fairness, increase utilization, decrease the number of drops, and minimize queueing delays. Thus, it induces a better management of the queue. A comparison of our scheme with preexistent schemes, like the explicit congestion notification scheme, shows the effectiveness of the proposed mechanism. 展开更多
关键词 Active queue management congestion control FAIRNESS transmission control protocol(TCP)
下载PDF
An Active Queue Management Algorithm: CRED 被引量:1
8
作者 LI Shi-ning SUN En-chang QIN Zheng 《International Journal of Plant Engineering and Management》 2006年第2期97-105,共9页
By applying the method of average and variance, a new queue management algorithm named the Classified-Random Early Detection (CRED) algorithm is presented which can identify the media streaming, TCP traffic and othe... By applying the method of average and variance, a new queue management algorithm named the Classified-Random Early Detection (CRED) algorithm is presented which can identify the media streaming, TCP traffic and other UDP traffic at the edge routers. The algorithm discriminates the slow start and the congestion control phase of the TCP traffic and combines the TCP congestion control with the IP congestion control to alleviate the congestion effectively. Simulation shows that CRED can not only make the media streaming obtain the resources needed but also protect the TCP traffic transmitted effectively and reliably. 展开更多
关键词 active queue management(AQM) CRED TCP congestion control IP congestion control
下载PDF
Two-Dimensional Electronic Spectroscopy with Active Phase Management
9
作者 Wei-da Zhu Rui Wang +2 位作者 Xiao-yong Wang Min Xiao Chun-feng Zhang 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2021年第1期30-42,I0011,共14页
Two-dimensional elec tronic spec troscopy(2DES)is a powerful met hod to probe the coherent electron dynamics in complicated systems.Stabilizing the phase difference of the incident ultrashort pulses is the mos t chall... Two-dimensional elec tronic spec troscopy(2DES)is a powerful met hod to probe the coherent electron dynamics in complicated systems.Stabilizing the phase difference of the incident ultrashort pulses is the mos t challenging par t for experimen tal demonstration of 2DES.Here,we present a tuto rial review on the 2DES proto cols based on active phase managements which are originally developed for quantum optics experiments.We introduce the 2DES techniques in box and pump-probe geometries with phase stabilization realized by interferometry,and outline the fully collinear 2DES approach with the frequency tagging by acoustic optical modulators and frequency combs.The combination of active phase managements,ultrashort pulses and other spectroscopic methods may open new opportunities to tackle essential challenges related to excited states. 展开更多
关键词 Two-dimensional electronic spectroscopy Active phase management Frequency comb
下载PDF
RED-DTB: A Dual Token Bucket Based Queue Management Algorithm
10
作者 YinJian-hua CaoYang +1 位作者 LingJun HuangTian-xi 《Wuhan University Journal of Natural Sciences》 EI CAS 2003年第02A期388-392,共5页
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 R... 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. 展开更多
关键词 Key words congestion control active queue management Dual Token Bucket fair bandwidth allocation network simulation
下载PDF
A Robust Algorithm in Active Queue Management
11
作者 秦凯运 谢剑英 《Journal of Donghua University(English Edition)》 EI CAS 2005年第4期98-102,共5页
A variable structure based control scheme was proposed for Active Queue Management(AQM) by using sliding model algorithm and reach law method. This approach aims to address the tradeoff between good performance and ro... A variable structure based control scheme was proposed for Active Queue Management(AQM) by using sliding model algorithm and reach law method. This approach aims to address the tradeoff between good performance and robustness with respect to the uncertainties of the round-trip time and the number of active connections. Ns simulations results show that the proposed design significantly outperforms the peer AQM schemes in terms of fluctuation in the queue length, packet throughput, and loss ratio. The conclusion is that proposed scheme is in favor of the achievement to AQM objectives due to its good transient and steady performance. 展开更多
关键词 Variable Structure Control Sliding Mode Active Queue management ROBUSTNESS
下载PDF
Multi-indicator Active Queue Management Method
12
作者 Mosleh M.Abualhaj Abdelrahman H.Hussein +1 位作者 Qasem M.Kharma Qusai Y.Shambour 《Computer Systems Science & Engineering》 SCIE EI 2021年第8期251-263,共13页
A considerable number of applications are running over IP networks.This increased the contention on the network resource,which ultimately results in congestion.Active queue management(AQM)aims to reduce the serious co... A considerable number of applications are running over IP networks.This increased the contention on the network resource,which ultimately results in congestion.Active queue management(AQM)aims to reduce the serious consequences of network congestion in the router buffer and its negative effects on network performance.AQM methods implement different techniques in accordance with congestion indicators,such as queue length and average queue length.The performance of the network is evaluated using delay,loss,and throughput.The gap between congestion indicators and network performance measurements leads to the decline in network performance.In this study,delay and loss predictions are used as congestion indicators in a novel stochastic approach for AQM.The proposed method estimates the congestion in the router buffer and then uses the indicators to calculate the dropping probability,which is responsible for managing the router buffer.The experimental results,based on two sets of experiments,have shown that the proposed method outperformed the existing benchmark algorithms including RED,ERED and BLUE algorithms.For instance,in the first experiment,the proposed method resides in the third-place in terms of delay when compared to the benchmark algorithms.In addition,the proposed method outperformed the benchmark algorithms in terms of packet loss,packet dropping,and packet retransmission.Overall,the proposed method outperformed the benchmark algorithms because it preserves packet loss while maintaining reasonable queuing delay. 展开更多
关键词 Congestion control network performance active queue management
下载PDF
Traffic Queuing Management in the Internet of Things: An Optimized RED Algorithm Based Approach
13
作者 Abdul Waheed Naila Habib Khan +4 位作者 Mahdi Zareei Shahab Ul Islam Latif Jan Arif Iqbal Umar Ehab Mahmoud Mohamed 《Computers, Materials & Continua》 SCIE EI 2021年第1期359-372,共14页
Congestion control is one of the main obstacles in cyberspace traffic.Overcrowding in internet traffic may cause several problems;such as high packet hold-up,high packet dropping,and low packet output.In the course of... Congestion control is one of the main obstacles in cyberspace traffic.Overcrowding in internet traffic may cause several problems;such as high packet hold-up,high packet dropping,and low packet output.In the course of data transmission for various applications in the Internet of things,such problems are usually generated relative to the input.To tackle such problems,this paper presents an analytical model using an optimized Random Early Detection(RED)algorithm-based approach for internet traffic management.The validity of the proposed model is checked through extensive simulation-based experiments.An analysis is observed for different functions on internet traffic.Four performance metrics are taken into consideration,namely,the possibility of packet loss,throughput,mean queue length and mean queue delay.Three sets of experiments are observed with varying simulation results.The experiments are thoroughly analyzed and the best packet dropping operation with minimum packet loss is identified using the proposed model. 展开更多
关键词 Random early detection(RED) active queue management(AQM) quality of service(QOS) THROUGHPUT
下载PDF
Fuzzy variable structure algorithms for active queue management with delay compensation
14
作者 Wang Mingzheng(王明政) Li Jianhua +1 位作者 Zhang Wenjun Zhu Hongwen 《High Technology Letters》 EI CAS 2005年第3期310-314,共5页
Based on the linearized model of the TCP connections through the congested routers, this paper puts forward an active queue management algorithm (FVS-T). The algorithm utilizes the fuzzy variable structure control alg... Based on the linearized model of the TCP connections through the congested routers, this paper puts forward an active queue management algorithm (FVS-T). The algorithm utilizes the fuzzy variable structure control algorithm with delay factor to compensate time varying round-trip times (RTT) and uncertainties with respect to the number of active TCP sessions. By analyzing the robustness and performance of the control scheme for the nonlinear TCP/AQM model, we show that the proposed design has good performance and robustness, which are central to the notion of AQM. Implementation issues were discussed and ns simulations were provided to validate the design and compare its performance to other peer schemes in different scenarios. The results show that the proposed design significantly outperforms the other congestion schemes in terms of packet loss ratio, throughput and buffer fluctuation. 展开更多
关键词 fuzzy variable structure control TCP/IP ECN active queue management (AQM) ROBUSTNESS
下载PDF
Active Management of the Third Stage of Labour: Knowledge and Challenges of Obstetric Caregivers in Selected Health Facilities in Fako Division, Cameroon
15
作者 Tih William Ntchompbopughu Egbe Obinchemti Thomas Tendongfor Nicholas 《Open Journal of Obstetrics and Gynecology》 2021年第12期1815-1835,共21页
<p> <span style="font-family:Verdana;"><b><span style="font-family:Verdana;">Background:</span></b></span><span style="font-family:Verdana;"&g... <p> <span style="font-family:Verdana;"><b><span style="font-family:Verdana;">Background:</span></b></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> In Cameroon, the decrease in MMR (Maternal Mortality Ratio) from PPH (Postpartum Haemorrhage) despite the reported use of the Active Management of the Third Stage of Labour (AMTSL) is slower than </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">what is </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">required to achieve the Third Sustainable Development Goal (SDG3) hence the need to question obstetric caregivers’ competence in AMTSL, as well as the factors hindering its proper use.</span><b> </b><span style="font-family:Verdana;">We therefore aimed to assess obstetric caregivers’ knowledge about AMTSL, as well as the determinants and barriers of AMTSL in selected hospitals in Fako Division, Cameroon.</span><b><span style="font-family:Verdana;"> Methods:</span></b><span style="font-family:Verdana;"> This was a hospital-based cross-sectional study of 150 participants recruited in 27 health facilities in Buea, Limbe and Tiko health districts from January 15, 2020, to March 31, 2020. Participants’ socio-demographic and qualification characteristics, knowledge and challenges, and the references guiding their practice of AMTSL were collected using a structured questionnaire. AMTSL knowledge was categorized as poor or good and the determinants of good AMTSL knowledge were evaluated. The data was analyzed in SPSS version 25.0. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> Of the 150 caregivers interviewed, only 48.7% had good knowledge of AMTSL. In logistic models, participants’ use of AMTSL increased Good knowledge of AMTSL (AOR: 12.96, CI: 1.12 -</span></span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">150.3, </span><i><span style="font-family:Verdana;">p</span></i></span></span></span><span><span><i><span style="font-family:""> </span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">=</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">0.04). Unavai</span><span style="font-family:Verdana;">lability of drugs and/or equipment, insufficient staff coverage and lack of kn</span><span style="font-family:Verdana;">owledge and training of the staff were the major challenges reported.</span><b><span style="font-family:Verdana;"> Conclu</span><span style="font-family:Verdana;">sion:</span></b><span style="font-family:Verdana;"> Obstetric caregivers in Fako division have knowledge gaps and face nu</span><span style="font-family:Verdana;">merous challenges in AMTSL use, which could account for the consistently high MMR from PPH. Filling this knowledge gap and mitigating the challenges </span><span style="font-family:Verdana;">of these caregivers would certainly accelerate progress</span><span style="font-family:Verdana;"> towards the achievement of SDG3. 展开更多
关键词 Active management of the Third Stage of Labour Postpartum Haemorrhage Obstetric Caregivers KNOWLEDGE CHALLENGES Determinants
下载PDF
Fuzzy variable structure delay control algorithms and their applications to AQM 被引量:1
16
作者 王明政 李建华 +1 位作者 张文军 诸鸿文 《Journal of Southeast University(English Edition)》 EI CAS 2004年第3期289-296,共8页
This paper analyzes the fuzzy variable structure control algorithms for delay systems and describes the compensation mechanism of the integral factor to the effect of the delay. Based on the linearized model of the co... This paper analyzes the fuzzy variable structure control algorithms for delay systems and describes the compensation mechanism of the integral factor to the effect of the delay. Based on the linearized model of the congestion-avoidance flow-control mode of transmission control protocol (TCP), we present delay control algorithms for active queue management (AQM) and discuss the parameter tuning of the algorithms. The NS (network simulator) simulation results show that the proposed control scheme for the nonlinear TCP/AQM model has good performance and robustness with respect to the uncertainties of the round-trip time (RTT) and the number of active TCP sessions. Compared to other similar schemes, our algorithms perform better in terms of packet loss ratio, throughput and butter fluctuation. 展开更多
关键词 time delay compensation fuzzy variable structure control active queue management ROBUSTNESS
下载PDF
Diffserv AQM algorithm for edge and core routers 被引量:2
17
作者 Yang Xiao Lingyun Lu Kiseon Kim 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第6期1033-1040,共8页
The existing active queue management (AQM) algorithm acts on subscribers and edge routers only, it does not support differentiate-serve (Diffserv) quality of service (QoS), while the existing diffserv QoS has no... The existing active queue management (AQM) algorithm acts on subscribers and edge routers only, it does not support differentiate-serve (Diffserv) quality of service (QoS), while the existing diffserv QoS has not considered the link capacities between edge routers and connected core routers. When a core router in a two layers’ network experiences congestion, the connected edge routers have no ability to adjust their access data rates. Thus, it is difficult to achieve the congestion control for the large scale network with many edge routers and core routers. To solve these problems, two difffserve AQM algorithms are proposed for the congestion control of multilayer network. One diffserv AQM algorithm implements fair link capacities of edge routers, and the other one implements unequal link capacities of edge routers, but it requires the core routers to have multi-queues buffers and Diffserv AQM to support. The proposed algorithms achieve the network congestion control by operating AQM parameters on the conditions of proposed three theorems for core and edge routers. The dynamic simulation results demonstrate the proposed control algorithms for core and edge routers to be valid. 展开更多
关键词 active queue management (AQM) core router control multilayer network.
下载PDF
Using Lyapunov function to design optimal controller for AQM routers 被引量:1
18
作者 ZHANG Peng YE Cheng-qing +2 位作者 MA Xue-ying CHEN Yan-hua LI Xin 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第1期113-118,共6页
It was shown that active queue management schemes implemented in the routers of communication networks sup-porting transmission control protocol (TCP) flows can be modelled as a feedback control system. In this paper ... It was shown that active queue management schemes implemented in the routers of communication networks sup-porting transmission control protocol (TCP) flows can be modelled as a feedback control system. In this paper based on Lyapunov function we developed an optimal controller to improve active queue management (AQM) router’s stability and response time, which are often in conflict with each other in system performance. Ns-2 simulations showed that optimal controller outperforms PI controller significantly. 展开更多
关键词 TCP flows Active queue management (AQM) Lyapunov function Optimal controls
下载PDF
Congestion control algorithm in large-delay uncertain networks 被引量:1
19
作者 Fengjie YIN Yuanwei JING Yuanjiu GONG 《控制理论与应用(英文版)》 EI 2007年第1期67-70,共4页
Based on Smith-fuzzy controller, a new active queue management (AQM) algorithm adaptable to the large-delay uncertain networks is presented. It can compensate the negative impact on the queue stability caused by the... Based on Smith-fuzzy controller, a new active queue management (AQM) algorithm adaptable to the large-delay uncertain networks is presented. It can compensate the negative impact on the queue stability caused by the large delay, and it also maintains strong robustness under the condition of dynamic network fluid. Its stability is proven through Lyapunov method. Simulation results demonstrated that this method enables the queue length to converge at a preset value quickly and keeps the queue oscillation small, the simulation results also show that the scheme is very robust to disturbance under various network conditions and large delay and, in particular, the algorithm proposed outperforms the conventional PI control and fuzzy control when the network parameters and network delay change. 展开更多
关键词 Congestion control Large delay Active queue management Smith predictor Fuzzy logic control
下载PDF
AN EFFECTIVE NETWORK CONGESTION CONTROL METHOD FOR MULTILAYER NETWORK 被引量:1
20
作者 Du Haifeng Xiao Yang Lu Lingyun 《Journal of Electronics(China)》 2008年第4期488-494,共7页
The congestion control problem in a single node network has been solved by the nonlinearfeedback control method,which has been proven to be effective and robust for different router’s queuesize.However,these control ... The congestion control problem in a single node network has been solved by the nonlinearfeedback control method,which has been proven to be effective and robust for different router’s queuesize.However,these control models are based on the single layer network architecture,and the sendersand receivers are directly connected by one pair of routers.With the network architecture being moreand more complex,it is a serious problem how to cooperate many routers working in the multilayernetwork simultaneously.In this paper,an effective Active Queue Management(AQM)scheme toguarantee the stability by the nonlinear control of imposing some restrictions on AQM parameter inmultilayer network is proposed.The nonlinear control can rely on some heuristics and network trafficcontrollers that appear to be highly correlated with the multilayer network status.The proposedmethod is based on the improved classical Random Early Detection(RED)differential equation and atheorem for network congestion control.The theorem proposed in the paper proved that the stability ofthe fluid model can effectively ensure the convergence of the average rate to its equilibrium pointthrough many routers in multilayer network.Moreover,when the network capacity is larger,theproposed scheme can still approach to the fullest extensibility of utilization and ensure the stability ofthe fluid model.The paper reveals the reasons of congestion control in multilayer network,provides atheorem for avoiding network congestion,and gives simulations to verify the results. 展开更多
关键词 Active Queue management (AQM) Nonlinear control Transmission Control Protocol (TCP) Random Early Detection (RED) Multilayer network
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部