We discuss an Integer programming model that was developed for classroom space planning at the Faculties of Engineering and Architecture at Dalhousie University. the model will be of interest to any facility planner w...
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Skeleton based libraries are considered one of the alternatives to reduce the distance between end users and parallel architectures. Algorithmic skeletons are based in general procedures describing the method to be im...
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ISBN:
(纸本)9783540681052
Skeleton based libraries are considered one of the alternatives to reduce the distance between end users and parallel architectures. Algorithmic skeletons are based in general procedures describing the method to be implemented. Although a gap between general formalizations for dynamic programming and software components can be found, we develop a skeleton tool for dynamic programming problems. the design strategy is general enough to consider a wide rage of dynamic programming recurrences. As usual in skeleton approaches, the parallelism is provided in a transparent manner, so that, sequential users may access to the system. A set of tests problems representative of different classes of dynamic programming formulations has been used to validate the distributed memory implementation on an IBM-SP.
Optimising non-functional properties of software is an important pall of the implementation process. One such property is execution time, and compilers target a reduction in execution time using a variety of optimisat...
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ISBN:
(纸本)9783540896937
Optimising non-functional properties of software is an important pall of the implementation process. One such property is execution time, and compilers target a reduction in execution time using a variety of optimisation techniques. Compiler optimisation is not always able to produce semantically equivalent alternatives that improve execution times, even if such alternatives are known to exist. Often, this is due to the local nature of such optimisations. In this paper we present a novel framework for optimising existing software using a hybrid of evolutionary optimisation techniques. Given as input the implementation of a program or function, we use Genetic programming to evolve it new semantically equivalent version, optimised to reduce execution time subject to it given probability distribution of inputs. We employ a co-evolved population of test cases to encourage the preservation of the program's semantics, and exploit the original program through seeding of the population in order to focus the search. We carry out experiments to identify the important factors in maximising efficiency gains. Although in this work we have optimised execution time, other non-functional criteria could be optimised in a similar manner.
We discuss our experience of using model-based techniques to generate model-based code generators. the central idea behind model-driven development (MDD) is to use suitable models to specify various concerns and trans...
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ISBN:
(纸本)9781605582672
We discuss our experience of using model-based techniques to generate model-based code generators. the central idea behind model-driven development (MDD) is to use suitable models to specify various concerns and transform these models to a variety of text artifacts. A business product needs to deliver a given business functionality on a wide variety of implementation platforms and architectures thus necessitating multiple sets of code generators. However, there is a considerable commonality across these code generators. In absence of a suitable abstraction for capturing this commonality, there is little or no reuse across these code generators. We present an abstraction for organizing model-based code generators as a hierarchical composition of reusable building blocks. A building block is a localized specification of a concern in terms of a concern-specific meta model, model to model transformation, and model to text transformation. Model-based code generation is a 3-step walk over the composition tree wherein the first step transforms individual concern-specific models into a unified model, the second step transforms the unified model into individual concern-specific text artifacts, and the third step composes these text artifacts.
Character order in Unicode for Bengali is different front the sorting order suggested by the governing authority. As a result, simple letter by letter comparison doesn't yield correct order of Bengali words. the p...
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ISBN:
(纸本)9781424420148
Character order in Unicode for Bengali is different front the sorting order suggested by the governing authority. As a result, simple letter by letter comparison doesn't yield correct order of Bengali words. the presence of modifier characters in Bengali made the situation more complicated. the objective of our study is to adapt the suggested collation order for Unicode represented Bengali text while achieving maximum possible efficiency. Here we propose an algorithm for this purpose. the proposed algorithm is applicable to any chosen sorting order. Also it compares words in O(1) time, irrespective of their lengths. thus complexity of sorting texts is always O(n log n).
In this paper, we develop heuristics for finding good starting points when solving large-scale nonlinear constrained optimization problems (COPS) formulated as nonlinear programming (NLP) and mixed-integer NLP (MINLP)...
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ISBN:
(纸本)9783540886358
In this paper, we develop heuristics for finding good starting points when solving large-scale nonlinear constrained optimization problems (COPS) formulated as nonlinear programming (NLP) and mixed-integer NLP (MINLP). By exploiting the localities of constraints, we first partition each problem by parallel decomposition into subproblems that are related by complicating constraints and complicating variables. We develop heuristics for finding good starting points that are critical for resolving the complicating constraints and variables. In our experimental evaluations of 255 benchmarks, our approach can solve 89.4% of the problems, whereas the best existing solvers can only solve 42.8%.
this paper(1) addresses issues associated with reduction of memory usage for a semidefinite programming (SDP) relaxation based method and its application to position estimation problem in ad-hoc wireless sensor networ...
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ISBN:
(纸本)9783540681052
this paper(1) addresses issues associated with reduction of memory usage for a semidefinite programming (SDP) relaxation based method and its application to position estimation problem in ad-hoc wireless sensor networks. We describe two new CSDP solvers (semidefinite programming in C) using two algorithms for Cholesky factorization implementing RFP and BHF matrix storage formats and different implementations of BLAS/LAPACK libraries (Netlib's BLAS/LAPACK, sequential and parallel versions of ATLAS, Intel MKL and GotoBLAS). the numerical results given and discussed in the final part of the paper show that using both RFP and BHF data formats preserve high numerical performance of the LAPACK full data format while using half the computer storage.
this paper shows an easy to use interface for applying the Discrete Sine Transform (DST) to a vector. this transform is an FFT-related routine and frequently used in many applications, such as, the translation of a cl...
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ISBN:
(纸本)9783540681052
this paper shows an easy to use interface for applying the Discrete Sine Transform (DST) to a vector. this transform is an FFT-related routine and frequently used in many applications, such as, the translation of a class of structured matrices into another class. the ease of use of the interface has been achieved by exploiting the interesting features of the Fortran 90/95 programming language. In addition, a technique has been incorporated to resolve the performance breakdown arising when the vector size cannot be decomposed into small prime numbers. this breakdown stems from the divide-and-conquer type of algorithms used when applying the DST.
Systems that are extended across multiple media, e.g., a mobile device and a desktop computer, are becoming increasingly popular. One reason for this is their ability to provide pervasive support for human activities ...
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ISBN:
(纸本)9781605581927
Systems that are extended across multiple media, e.g., a mobile device and a desktop computer, are becoming increasingly popular. One reason for this is their ability to provide pervasive support for human activities across a range of contextual settings. Despite the value that these cross media systems offer, there are aspects that detract from their efficient utilization. this article reports the findings from an empirical case study exploring the adoption and use of a cross media fitness system. the system's general fit withthe ways users carry out their activities is a central determinant of utilization. However, the adoption and use of a cross media system is also essentially influenced through the user experience process. this article describes distinct system characteristics that were found to influence coherent user experience. Based on these findings, we propose design responses that address a systemic out of box experience, crossmedial referencing and explication of a holistic system image. this study provides new insight into how users interact with and perceive cross media systems and identifies distinct focus areas for future research and design of heterogeneous and pervasive information technology. Copyright 2008 ACM.
Multi-processor system-on-chip (MPSoC) technology is finding widespread application in the embedded system domain, like in cell phones, automotive control units or avionics. Once deployed in field, these devices alway...
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ISBN:
(纸本)9783540899815
Multi-processor system-on-chip (MPSoC) technology is finding widespread application in the embedded system domain, like in cell phones, automotive control units or avionics. Once deployed in field, these devices always run the same set of applications, in a well-characterized context. It is therefore possible to spend a large amount of time for off-line software optimization and then deploy the results on the field. Each possible set of applications that can be active simultaneously in an MPSoC platform leads to a different use-case that the system has to be verified and tested for. Above all, smooth switching between use-cases falls within the scope of the resource manager, since users should not experience artifacts or delays when a transition between any two consecutive use-cases takes place. In this paper, we propose a semi-static approach to the resource management problem, where the allocation and scheduling solutions for the tasks in each use-case are computed off-line via a Logic Based Benders Decomposition approach using Constraint programming and stored for use in run-time mapping decisions. the solutions are logically organized in a lattice, so that the transition costs between any two consecutive use-cases can be bound. the resulting framework exhibits both a high level of flexibility and orders of magnitude speed ups w.r.t. monolithic approaches that do not exploit decomposition
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