14381904
Scheduling sports competitions at multiple venues - Revisited
Abstract In this work, we study scheduling sports competitions at multiple venues, a problem recently introduced by Urban and Russell [T.L. Urban, R.A. Russell, Scheduling sports competitions on multiple venues, European Journal of Operational Research 148 (2003) 302–311]. The distinguishing feature of the problem is that venues come into play when scheduling. We develop beam search and simulated annealing approaches to the problem and its extension. Computational experiments were conducted and algorithms compared and analyzed. We found that the simulated annealing algorithm with specialized neighborhood moves achieved superior solutions in significantly shorter times than the method of Urban and Russell.
110721483
An Internet based virtual exhibition system: conceptual design and infrastructure
Abstract Virtual reality technology has wide applications in manufacturing, service industry, and medical training. In addition to essential presence, virtual reality provides secure and economical environment for participants to experience the virtual world rather than the corresponding real world. With advent of rapidly developed technology, there are numerous new products and projects to be introduced in exhibition shows over the world everyday and it is neither prudent nor possible to attend all of them. There have been overwhelming amount of virtual exhibitions available on the Internet; however, most of them are not satisfactory in terms of performance and users cannot get a full understanding on the product interested due to low sense of presence. Information coordination, other than information share and distribution, between the participants is crucial but not yet well defined in the current virtual exhibitions. It is prominent to develop Internet based virtual reality exhibition systems that agglomerate the advantages of efficiency/accessibility on the Internet and high sense of presence in virtual environment. The Internet based virtual exhibition systems are not only as informative as traditional exhibitions but also more flexible to relax temporal and spatial constraints to allow users attend exhibitions anytime and anywhere.
35595997
Parallel simulation of a multi-dimensional computational fluid dynamics problem
The simulation of computational fluid dynamics problems in two and more dimensions involves computations of multiple degrees of freedom, such as the components of velocity, which are an obvious source of parallelism. Further to our previous investigation in this area we report on our current experiences in extracting such parallelism on a distributed network platform. A finite element method for simulating incompressible viscous flows is parallelised using a domain decomposition approach. Various issues that arise in this implementation are discussed in the light of our experimental results.
14428836
Protein structure prediction by a data-level parallel algorithm
We have developed a software system, PHI-PSI, on the Connection Machine that uses a parallel algorithm to retrieve and use information from a database of 112 known protein structures (selected from the Brookhaven Protein Databank) to predict the structures of other proteins. The φ and angles of each amino acid (the angles each amino acid forms with its immediate neighbors) in a protein are used to represent its 3-D structure. PHI-PSI's algorithm is based on the idea of Memory-based reasoning (MBR) [10] and extends it to include a recursive procedure to refine its initial prediction and a “window” of varying sizes to look at different contexts of an input. PHI-PSI has been tested with all the available data. Initial results show that it performs better than distribution-based guesses for most of the φ and angle values.
59762733
The application of artificial neural networks in editing noisy seismic data
16742949
Evaluation of the matrix exponential function using finite elements in time
The evaluation of a matrix exponential function is a classic problem of computational linear algebra. Many different methods have been employed for its numerical evaluation (Moler C and van Loan C 1978 SIAM Review 20 4), none of which produce a definitive algorithm which is broadly applicable and sufficiently accurate, as well as being reasonably fast. Herein, we employ a method which evaulates a matrix exponential as the solution to a first-order initial value problem in a fictitious time variable. The new aspect of the present implementation of this method is to use finite elements in the fictitious time variable. (Weatherford C A, Red E, and Wynn A 2002 Journal of Molecular Structure 592 47) Then using an expansion in a properly chosen time basis, we are able to make accurate calculations of the exponential of any given matrix as the solution to a set of simultaneous equations.
41465544
Towards automated progress assessment of workpackage components in construction projects using computer vision
Traditional methods of collecting data on the progress of construction projects often involve human judgement, high costs, and are too infrequent to provide managers with timely and accurate control data. This study proposes a system that aims to address some of these shortcomings through automation. Our first contribution is a framework for the automatic generation of work packages. We describe the conceptual model and develop a prototype implementation, based on the results of a survey designed to capture the current practice of formulating work packages as performed in the industry. Our second contribution is a system that employs computer vision (CV) techniques to report on the progress of these work packages automatically. This is achieved by analysing sequences of digital images acquired regularly by on-site cameras. The result of this analysis, when compared with the expected state of construction, provides progress feedback on the work packages, allowing a project to be monitored more effectively.