基于改进蚂蚁算法的IP over ATM下多路径选择

随着网络多种业务的发展,人们对服务质量(QOS)提出了很高的要求,IPoverATM技术将成为未来网络的主流,但这加大了路由选择的复杂性。传统的蚂蚁算法虽然能较快地找到一条最优路径,但是容易造成该路径上的拥塞,而且无法解决这一状况。可对多路径改进的蚂蚁算法进行改进,当最优路径处于拥塞状态时,该算法将绕过处于拥塞的节点重新搜索新的“次优”路径对原最优路径分流,这样既保证了服务质量,又达到优化路由选择的目的。

Comparison of tropical cyclone thermal structures derived from ATMS and synthetic AMSU-A/MHS

热带气旋(TC)的暖心反映了其强度和变化.微波探测数据被广泛用于探测TC暖心,但观测到的TC暖心强度可能因仪器而异.本研究利用先进技术微波探测仪(ATMS)的过采样数据重采样至与先进微波探测仪(AMSU-A)一致的亮温,称为类AMSU数据.通过对比发现,ATMS的观测更加细致,较好地刻画了TC眼区和云带.使用ATMS和类-AMSU数据反演多个TC的暖心发现,在250 hPa,使用ATMS数据反演的暖心强度比类-AMSU高约1-2K,并且其暖心结构更详细.

HYBRID STRATIFIED ATMS AND ANN FOR CASE-BASED REASONING

Case Based Reasoning (CBR) is a powerful problem solving technique in AI, but the traditional CBR techniques have its limitations. We hybridized stratified ATMS and ANN for CBR which can deal with case representation, case retrieving, case adapting, learning from failure more effectively. The structure of our CBR system and algorithms of case base reasoning in our CBR system were presented.

A CONNECTION ADMISSION CONTROL SCHEME BASED ON GAME THEORETICAL MODEL IN ATM NETWORKS

In this paper, the main schemes of connection admission control (CAC) in ATM networks are briefly discussed especially the principle of dynamic bandwidth allocation. Then the fair share of the bandwidth among different traffic sources is analyzed based on cooperative game model. A CAC scheme is proposed using the genetic algorithm (GA) to optimize the bandwidth-delay-product formed utilization function that ensures the fair share and accuracy of accepting/rejecting the incoming calls. Simulation results show that the proposed scheme ensures fairness of the shared bandwidth to different traffic sources.

A New SDH-Based ATM Network Survivability Escalation Mechanism

This paper investigates survivability escalation strategies in multi layers transport networks such as ATM/SDH/WDM networks, and presents oriented failures and oriented traffic escalation mechanisms. Furthermore, We present a new survivability Escalation strategy for SDH Based ATM transport networks, which addresses difficult problem for resources sharing pool(RSP) among different layers restoration mechanisms. In this paper, we also present integer programming (IP) model for the resources sharing pool (RSP) design problem and the node simulation model for escalation Node. The simulation results show that the proposed ESP is very efficient. The proposed model can be easily extended for other types of multi layer networks, such as WDM based ATM networks or WDM based SDH networks.

ANALYSIS OF THE LEAKY BUCKET OUTPUT PROCESSES FOR BURSTY SOURCES IN ATM NETWORKS

In ATM networks, bursty sources can be described as the Interrupted Bernoulli Process(IBP). With the use of the thin process theory, the Probability Generating Function(PGF) of the IBP is obtained. An iterative algorithm, which can be used to calculate the IBP probability distribution, is presented. The bursty source’s equivalent description is discussed. It is proposed that the leaky bucket output process can be approximately described as the IBP. The accuracy of the analytical results has been largely validated by means of the simulation approach. Moreover, how to improve its accuracy is discussed. The smoothing function of the leaky bucket algorithm is quantitatively analyzed.

BUFFER DIMENSIONING FOR RATE-BASED CONTROL IN ATM NETWORK

Available Bit Rate (ABR) service has been developed to support data applications to asynchronous transfer mode (ATM) networks.Since a ratebased feedback flow control mechanism has been selected as a standard by ATM Forum,buffering becomes an issue that needs intensive study.In this paper,the queuing performance in a switch is studied in detail.It is theoretically proven that the goals of no cell loss and full utilization of link capacity can be achieved by choosing an appropriate buffersize and threshold of the switch buffer which is supported by our simulation results of a complex network.

PERFORMANCE ANALYSIS OF LEAKY BUCKET ALGORITHM WITH BURSTY TRAFFIC INPUT IN ATM NETWORKS

A bursty traffic model is introduced in this paper to describe the statistical characteristics of packet video. The performance of leady bucket algorithm with bursty traffic input is analyzed. The influences of various parameters on QOS (Quality of Service) are investigated. The analysis shows that although the loss probability decreases through expanding the buffer capacity, the delay and delay jitter increase, whose effect on QOS will not be negligible.

A Comparative Study and Performance Analysis of ATM Card Fraud Detection Techniques

ATM card fraud is increasing gradually with the expansion of modern technology and global communication. In the whole world, it is resulting in the loss of billions of dollars each year. Fraud detection systems have become essential for all ATM card issuing banks to minimize their losses. The main goals are, firstly, to review alternative techniques that have been used in fraud detection and secondly compare and analyze these techniques that are already used in ATM card fraud detection. Recently different card security systems used different fraud detection techniques;these techniques are based on neural network, genetic algorithm, hidden Markov model, Bayesian network, decision tree, clustering method, support vector machine, etc. According to our survey, the most important parameters used for comparing these fraud detection systems are accuracy, speed and cost of fraud detection. This study is very useful for any ATM card provider to choose an appropriate solution for fraud detection problem and also enable us to build a hybrid approach for developing some effective algorithms which can perform properly on fraud detection mechanism.

Inhibitory Effect of α-Pinene on SGC-7901 Cell Proliferation and the Mechanism of ATM Kinase Signaling Pathway

Objective: To research the inhibitory effect on SGC-7901 cells of α-pinene, and the related mechanism of α-pinene. Methods: Used the MTT method to detect inhibition rate and western blotting to detect the influence on expression of ATM, Phos-S1981ATM, H2AX, γH2AX, CHK2 and p-CHK2, p53 and phos-p53 cell cycle related protein in SGC-7901 cells. Results: The research found α-pinene could inhibit the proliferation of SGC-7901 cells observably in vitro, and the inhibition rate assumes the dependence on concentration;and western blotting results showed that, α-pinene could activate phospho-ATM, increase the amount of γH2AX (p p < 0.05);increase the expression of p-CHK2, p53 and phos-p53 (p p p < 0.05);But there is no significant effect on expression of CHK2 (p > 0.05). Conclusions: α-pinene could inhibit the proliferation of SGC-7901 cells, and by inducing ATM (Ataxia Telangiectasia-Mutated) kinase signal pathway in DNA damage response, activating cell cycle checkpoint, making the cell cycle arrest then exerts its anti-tumor effects.

GLTSCR1, ATM, PPPIR13L and CD3EAP Genetic Variants and Lung Cancer Risk in a Chinese Population

Genetic variants in glioma tumor suppressor candidate region gene 1 （GLTSCR1） and ATM serine/threonine kinase （ATM） have been associated with various cancer risks. Epidemiological studies also revealed the association of variants of GLTSCR1 and ATM genes with different brain tumors. However, little is known about the relationship between both gene polymorphisms and lung cancer risk. We conducted a Chinese hospital-based casecontrol study involving 384 lung cancer cases and 387 cancer-free controls. No significant differences in the single polymorphism （GLTSCR1 rs1035938 and ATM rs11212592） association were found in five genetic models （co-dominant, dominant, recessive, overdominant and log-additive models） （adjusted by smoking duration）. Join effect of three SNPs （PPPIR13L rs1970764, CD3EAP rs967591, GLTSCR1 rs1035938） on chromosome 19q 13.3 showed that the designated haplotype2 （rs 1970764 G-rs967591 A-rs 1035938 C） [OR （95% CI）=1.60 （1.11-2.32）, P=0.012] and haplotype8 （rs 1970764 G-rs967591 G-rs 1035938 T） [OR （95% CI）=2.45 （1.17-5.12）, P=0.018] were associated with increased risk of lung cancer （adjusted by smoking duration）. The analysis ofmultifactor dimensionality reduction revealed that two 3-way models were the best fit models in analyses of 2 loci （P〈0.001） or 4 loci （P=0.015-0.016）. The entropy-based analysis indicated the strongest synergistic effect between PPPIR13L rs1970764 and ATM rs11212592 in analysis of four genes. In conclusion, our study suggests that haplotypes consisting of PPPIR13L rs1970764- CD3EAP rs967591-GLTSCR1 rs1035938 on Chr19q13.3, interaction of smoking and GLTSCR1 rs1035938-ATM rs11212592, and synergistic action of PPPIR13L rs1970764 and ATM rs 11212592 may associate with lung cancer risk in the Chinese population.

IP over SDH与IP over ATM比较

现代远程教育是近年来国际教育发展的重要趋势。该文简单介绍了SDH和ATM技术,将IPoverSDH和IPoverATM从协议开销、带宽管理、服务质量、地址分配、路由及流控等方面进行了全面的比较。最后,给出了在现代远程教育中选择这两种技术的指南。对现代远程教育的具体实施具有一定的参考价值。

Research of Queuing Disciplines and Their Performances in ATM Switch

This paper introduces the principle of ATM switch, and discusses queueing disciplines and their performances. Authors describe the method of input queueing, output queueing, central queueing, combined input/output queuing, combined input/shared queueing, and multistage queueing in detail. They also present the relations between mean waiting time and input load. The queueing disciplines can be used to design the architecture of Asynchronous Transfer Mode (ATM) switch.

DELAY JITTER OF A PERIODIC CELL STREAM THROUGH AN ATM MULTIPLEXER IN A BURSTY TRAFFIC ENVIRONMENT

The periodic cell stream is a very important member among the input traffic sources in ATM networks. In this paper, a finite-buffered ATM multiplexer with traffic sources composed of a periodic cell stream, multiple i.i.d Bernoulli cell streams and bursty two-state Markov Modulated Bernoulli Process (MMBP) cell streams is exactly analyzed. The probability mass function of queuing delay, the autocorrelation and power spectrum of delay jitter for this periodic cell stream are derived. The analysis is used to expose the behavior of delay jitter for a periodic cell stream through an ATM multiplexer in a bursty traffic environment. The simulation results indicate that the analytical results are accurate.

PERFORMANCE ANALYSIS FOR ATM SWITCHING OF MIXED CONTINUOUS-BIT-RATE AND BURSTY TRAFFIC WITH SMOOTHING FUNCTION

Traditional packet switching networks have typically employed window-based congestion control schemes in order to regulate traffic flow. In ATM networks, the high speed of the communication links and the varied nature of the carried traffic make such schemes inappropriate. Therefore, simpler and more efficient schemes have to be proposed to improve the congestion control for ATM switching. This paper presents an exact performance analysis of ATM switching whose inputs consist of Continuous-Bit-Rate(CBR) and bursty traffic. The CBR traffic and bursty traffic are described by Bernoulli process and the Interrupted Bernoulli Process(IBP), respectively. Bursty traffic smoothing mechanism is analyzed. With the use of a recursive algorithm, the cell loss probability and the average delay for ATM switching of mixed CBR and bursty traffic are exactly calculated. Traffic smoothing could be implemented at a slower peak rate keeping the average rate constant or decreasing the average bursty length. Both numerical

DYNAMIC BANDWIDTH ALLOCATION IN AN ATM MULTIPLEXER WITH MULTICLASS TRAFFIC AND ITS PERFORMANCE ANALYSIS

This paper introduces two source models: MAP(Markovian arrival process) model for the traffic with correlation and burst, e.g., voice, video, etc. and PAP(Poisson arrival process) model for the traffic with non-correlation, such as data, etc. Then a movable boundary bandwidth access policy is chosen.Basing on above model, the performance measures, e.g., mean waiting time and loss probability,especially the queue length time distribution are obtained. Finally, a number of numerical results are provided and shown through simulation.

Functional switching of ATM:sensor of DNA damage in proliferating cells and mediator of Akt survival signal in post-mitotic human neuron-like cells

Ataxia-telangiectasia(A-T) is an autosomal recessive disorder characterized by cerebellar ataxia and oculocutaneous telangiectasias.The gene mutated in this disease,ATM(A-T,mutated),encodes a 370-kDa Ser/Thr protein kinase.ATM not only mediates cellular response to DNA damage but also acts as an activator of Akt in response to insulin.However,despite intensive studies,the mechanism underlying the neuronal degeneration symptoms of human A-T is still poorly understood.We found that the topoisomerase inhibitors etoposide and camptothecin readily induced apoptosis in undifferentiated proliferating SH-SY5Y cells but could not induce apoptosis in neuronally differentiated SH-SY5Y cells.In addition,etoposide induced p53 phosphorylation and H2AX foci formation in proliferating SH-SY5Y cells but failed to do so in differentiated SH-SY5Y cells.Moreover,while inhibition of ATM in undifferentiated SH-SY5Y cells partially protected them from etoposide-induced apoptosis,the same treatment had no effect on cell viability in differentiated SH-SY5Y cells.These results suggest that DNA damage or defective response to DNA damage is not the cause of neuronal cell death in human A-T.In contrast,we discovered that Akt phosphorylation was inhibited when ATM activity was suppressed in differentiated SH-SY5Y cells.Furthermore,inhibition of ATM induced apoptosis following serum starvation in neuronally differentiated SH-SY5Y cells but could not trigger apoptosis under the same conditions in undifferentiated proliferating SH-SY5Y cells.These results demonstrate that ATM mediates the Akt signaling and promotes cell survival in neuron-like human SH-SY5Y cells,suggesting that impaired activation of Akt is the reason for neuronal degeneration in human A-T.

On Some Key Technologies of ATM Switching

In this paper,the functions and the architecture of an ATM exchange are summarized.The switching fabrics,the line interface module and the control module are discussed in de-tail.An ATM switching system that adopts the scheme described in this paper has been de-veloped.

VBR WAVELET VIDEO CODING AND ITS RATE CONTROL IN ATM NETWORKS

This paper presents a new video coding system based on wavelet transform and its rate control scheme over ATM networks. First, three dimensional wavelet transform is performed for the original image sequence, and an extension of set partitioning in hierarchical trees algorithm is employed to quantize the wavelet coefficients. Then, the output rate of the coder is controlled at group of frame scale, ensuring that it conforms to the parameters of a leaky bucket controller. Several leaky buckets with different sizes are discussed too. Simulation shows the efficiency of this codec and the effectiveness of the proposed rate control scheme.

A DYNAMIC TRANSMISSION CAPACITY ALLOCATION SCHEME FOR WIRED/WIRELESS ATM NETWORKS

The previous research on administration of the transmission capacity in the wired/ wireless ATM networks only focuses on wired part or wireless part. There are very few people do the work extending to the links associating with handoff in the whole network. This paper develops the algorithms of transmission capacity administration on the link connecting the base station and base station controller (including the air interface of the base station) and the VPs among the base station controllers in the wired/ wireless ATM networks, which adapt to the traffic state of each service in every cellular cell to allocate (provision) transmission capacity and to reserve handoff guard capacity on these links, respectively. By simulating and analyzing the performance of the algorithm, it is found that it does well for the multimedia communication in which the transmission capacity requirement of each service may be widely different, so that the network bandwidth resource can be used efficiently.