Optimization of Operation Sequencing in CAPP Using Hybrid Genetic Algorithm and Simulated Annealing Approach

In any CAPP system, one of the most important process planning functions is selection of the operations and corresponding machines in order to generate the optimal operation sequence. In this paper, the hybrid GA-SA algorithm is used to solve this combinatorial optimization NP (Non-deterministic Polynomial) problem. The network representation is adopted to describe operation and sequencing flexibility in process planning and the mathematical model for process planning is described with the objective of minimizing the production time. Experimental results show effectiveness of the hybrid algorithm that, in comparison with the GA and SA standalone algorithms, gives optimal operation sequence with lesser computational time and lesser number of iterations

Trustworthy Knowledge Planes For Federated Distributed Systems

In federated distributed systems, such as the Internet and the public cloud, the constituent systems can differ in their configuration and provisioning, resulting in significant impacts on the performance, robustness, and security of applications. Yet these systems lack support for distinguishing such characteristics, resulting in uninformed service selection and poor inter-operator coordination. This thesis presents the design and implementation of a trustworthy knowledge plane that can determine such characteristics about autonomous networks on the Internet. A knowledge plane collects the state of network devices and participants. Using this state, applications infer whether a network possesses some characteristic of interest. The knowledge plane uses attestation to attribute state descriptions to the principals that generated them, thereby making the results of inference more trustworthy. Trustworthy knowledge planes enable applications to establish stronger assumptions about their network operating environment, resulting in improved robustness and reduced deployment barriers. We have prototyped the knowledge plane and associated devices. Experience with deploying analyses over production networks demonstrate that knowledge planes impose low cost and can scale to support Internet-scale networks

Creosote Treated Timber in the Alaskan Marine Environment

Creosote is a wood preservative that is used in marine structures in Alaska, such as piles, docks, and floating structures. Some of the PAH chemicals in creosote are toxic to marine organisms, and resources agencies and environmental groups question its use. Mesoscale testing of creosoted wood has not indicated significant negative effects of wood treated with Best Management Practices (BMP), which is now standard practice. The EPA pesticide recertification of creosote required only the use of BMP or a risk assessment. The National Marine Fisheries Service issued draft guidelines for wood preservatives, which does not preclude use of creosote, but suggest a risk assessment if the qualities of treated wood are large or they are installed in sensitive areas. This report recommends consideration of the risks of creosote and presents an algorithm for analyzing the risks. Many applications require only an overview risk assessment. Applications of large quantities of preserved wood or in sensitive areas should have a more formal risk assessment. The report and the EPA recertification suggest a screening assessment published by the Western Wood Preservers Institute. If the screening indicates further assessment is needed, the report points to more detailed assessments.State of Alaska, Alaska Dept. of Transportation and Public Facilitie