A comprehensive study on backup-bandwidth reprovisioning after network-state updates in survivable telecom mesh networks

title: An Efficient Approach for Service Process Reconfiguration in SOA with End-to-End QoS Constraints
abstract: Using SOA, service processes can be composed statically or dynamically using services provided by different service providers. Some services may become faulty at runtime and cause the service process to violate the end-to-end quality of service (QoS) constraint. We propose an efficient approach for replacing faulty services to ensure that the reconfigured service process still meets the original end-to-end QoS constraint. We use an iterative algorithm to identify reconfiguration regions that have a small number of services, some faulty and some healthy, in order to have more service selection options. By reconfiguring services in these selected regions rather than the whole service process, the computational complexity is significantly reduced. Simulation study has shown that our approach is efficient as most service processes can be repaired by replacing only a small number of services.

title: A Hybrid Restoration Scheme Based on Threshold Reaction Time in Optical Burst-Switched Networks
abstract: Optical Burst-Switched (OBS) networks usually employ one-way reservation by sending a burst control packet (BCP) with a specific offset time, before transmitting each data burst frame (BDF). Therefore, a fiber link failure may lead to loss of several BDFs as the ingress nodes sending these BDFs remain unaware of the failed link till they receive the failure indication signal (FIS). In this paper, we propose a hybrid restoration scheme, wherein we employ a novel combination of sub-path as well as path restoration schemes. In particular, the upstream node preceding the failed link employs sub-path restoration as soon as it detects the failure. Thereafter, when the source ingress node receives the FIS message, it (source ingress node) takes over the responsibility and employs path restoration. However, sub-path restoration is exercised by the upstream node only if the remaining time intervals left for the yet-to-arrive BDFs (for which BCPs have already left the upstream node) are less than a minimum time interval (called as threshold reaction time). Performance of the proposed scheme is evaluated through extensive computer simulation using OPNET. Our results indicate that the proposed restoration scheme significantly reduces burst losses due to link failure and, thus, outperforms the existing restoration schemes.

title: Explicit Routing for Traffic Engineering in Labeled Optical Burst-Switched WDM Networks
abstract: Optical burst switching (OBS) is a promising technique for supporting high-capacity bursty data traffic over optical wavelength-division-multiplexed (WDM) networks. A label-switched path can be established to forward a burst control packet (BCP) if each OBS node is augmented with an IP/MPLS controller. Such a network is called a labeled OBS (LOBS) network, and it can exploit the explicit routing and constraint-based routing properties supported in the MPLS framework to perform traffic and resource engineering. In this paper, we consider the traffic-engineering problem in a LOBS network, using explicit routing to balance network load and to reduce the burst-loss probability. We model the traffic-engineering problem in a LOBS network as an optimization problem and propose two new objective functions to minimize network congestion. Our illustrative numerical examples show that the burst-loss probability can be significantly reduced using optimization technique, when compared with shortest-path routing.

title: Availability-Aware Provisioning Strategies for Differentiated Protection Services in Wavelength-Convertible WDM Mesh Networks
abstract: In an optical WDM mesh network, different protection schemes (such as dedicated or shared protection) can be used to improve the service availability against network failures. However, in order to satisfy a connections service-availability requirement in a cost-effective and resource-efficient manner, we need a systematic mechanism to select a proper protection scheme for each connection request while provisioning the connection. In this paper, we propose to use connection availability as a metric to provide differentiated protection services in a wavelength-convertible WDM mesh network. We develop a mathematical model to analyze the availabilities of connections with different protection modes (i.e., unprotected, dedicated protected, or shared protected). In the shared-protection case, we investigate how a connection's availability is affected by backup resource sharing. The sharing might cause backup resource contention between several connections when multiple simultaneous (or overlapping) failures occur in the network. Using a continuous-time Markov model, we derive the conditional probability for a connection to acquire backup resources in the presence of backup resource contention. Through this model, we show how the availability of a shared-protected connection can be quantitatively computed. Based on the analytical model, we develop provisioning strategies for a given set of connection demands in which an appropriate, possibly different, level of protection is provided to each connection according to its predefined availability requirement, e.g., 0.999, 0.997. We propose integer linear programming (ILP) and heuristic approaches to provision the connections cost effectively while satisfying the connections' availability requirements. The effectiveness of our provisioning approaches is demonstrated through numerical examples. The proposed provisioning strategies inherently facilitate the service differentiation in optical WDM mesh networks.

title: The LLAMA Middleware Support for Accountable Service-Oriented Architecture
abstract: Enterprises are turning to SOA for the flexible deployment of business processes. While current monitoring tools can detect service execution problems in an enterprise's servers and report such problems to human decision makers, they may not closely monitor the external services they use, diagnose the root cause of process problems, and automatically reconfigure the process to replace faulty services. This paper presents the LLAMA middleware support for service process monitoring, run-time management, and configuration. Instances of accountability agents are deployed to selectively monitor some services' performance. These agents in turn allow LLAMA's Accountability Authority (AA) to diagnose process problems and apply any necessary reconfiguration. The project also builds tools to simplify the setup and deployment of LLAMA components. Our experimental results indicate that using LLAMA contributes only a modest amount of system overhead, and that the diagnosis process is swift and sufficiently accurate.

title: An Improved Immune Evolutionary Algorithm for Multimodal Function Optimization
abstract: Based on the inspiration of immune system, a new multi-objective optimization algorithm is presented. The proposed approach adopts a cluster mechanism in order to divide the population into subpopulations for the stage of selection and reproduction. In the immune clonal selection process, a hybrid hypermutation operator is introduced to improve the variety of antibodies and affinity maturation, thus it can quickly obtain the global and local optima. The simulation results illustrated that the efficiency of the proposed algorithm for complicated function optimization and verified it's remarkable quality of the global and local convergence reliability.

title: ATID: a web-oriented database for collection of publicly available alternative translational initiation events
abstract: Alternative translational initiation is an important cellular mechanism contributing to the diversity of protein products and functions. We develop a database that provides a comprehensive collection of alternative translational initiation events. The purpose of this alternative translational initiation database (ATID) is to facilitate the systematic study of alternative translational initiation of genes. The current version of database contains 300 genes from Homo sapiens, Mus musculus and other species. Each of the genes has two or more isoforms due to alternative translational initiation. Resources in ATID, including gene information, alternative products of genes and domain structures of isoforms, are provided through a user-friendly web interface.


AVAILABILITY
The ATID database is available for public use at http://bioinfo.au.tsinghua.edu.cn/atie/.

title: MDDAS 2008 Workshop Organization
abstract: A combination capacitor and transistor structure is described wherein the capacitor is formed integrally with the emitter electrode of the transistor. The transistor is formed in a monolithic integrated circuit using generally known techniques and constitutes a vertically integrated PNP device. The emitter electrode of the transistor which comprises a P+ diffusion region is of a predetermined area which is large enough to form the bottom plate of the capacitor. The top plate of the capacitor is formed by growing a dielectric material over the diffused emitter region and then forming metallization thereover. The combination capacitor and transistor structure may be utilized in a bias network for biasing the output stage of an operational amplifier in a class AB mode. The capacitor formed in the combination structure may be utilized as the compensation capacitor in such operational amplifier which utilizes pole splitting techniques. The improvement provided by the invention reduces the surface area of the semiconductor die chip required to form the capacitor and transistor which facilitates greater device density on a particular die chip.

title: North American digital government working group: initial steps in the development of a comparative and transnational agenda
abstract: This poster describes the first year's progress of the North American Digital Government Working Group on Comparative and Transnational Digital Government. This group was formed in 2007, with the support of the NSF Digital Government Research Program and the home institutions of the members in Canada, Mexico, and the U. S., to advance e-government research across geographic and political boundaries in the region. During the first year of activities, the group members joined their expertise and interests in two face-to-face meetings. Several intellectual products emerged from these initial interactions. The group members will continue the discussion of its research agenda in Montreal, Canada as part of the activities of the 9th Annual International Conference on Digital Government Research.

title: Information Strategies to Support Full Information Product Pricing: the Role of Trust
abstract: In this paper, we report the importance of trust in the development and operation of distribution networks that attach non-price information to products to mitigate market dynamics introduced by information asymmetries. Often this non-price information is transmitted from producers to consumers through trusting networks or under certifiable labels such as Organic or Fair Trade. We are calling such networks Full Information Product Pricing (FIPP) Networks. This study is part of a larger project aimed at understanding the characteristics of FIPP networks. This initial exploration on four cases in Canada and Latin America indicated that trust, in the forms of institutional trust, calculative trust, and relational trust, plays key roles in FIPP operations and expansion. It is critical for building collaboration, coordinating network activities, and mitigating the risks associated with information asymmetry.