1,004 research outputs found
Random Costs in Combinatorial Optimization
The random cost problem is the problem of finding the minimum in an
exponentially long list of random numbers. By definition, this problem cannot
be solved faster than by exhaustive search. It is shown that a classical
NP-hard optimization problem, number partitioning, is essentially equivalent to
the random cost problem. This explains the bad performance of heuristic
approaches to the number partitioning problem and allows us to calculate the
probability distributions of the optimum and sub-optimum costs.Comment: 4 pages, Revtex, 2 figures (eps), submitted to PR
Comparative Methods for Gene Structure Prediction in Homologous Sequences
The increasing number of sequenced genomes motivates the use of evolutionary patterns to detect genes. We present a series of comparative methods for gene finding in homologous prokaryotic or eukaryotic sequences. Based on a model of legal genes and a similarity measure between genes, we find the pair of legal genes of maximum similarity. We develop methods based on genes models and alignment based similarity measures of increasing complexity, which take into account many details of real gene structures, e.g. the similarity of the proteins encoded by the exons. When using a similarity measure based on an exiting alignment, the methods run in linear time. When integrating the alignment and prediction process which allows for more fine grained similarity measures, the methods run in quadratic time. We evaluate the methods in a series of experiments on synthetic and real sequence data, which show that all methods are competitive but that taking the similarity of the encoded proteins into account really boost the performance
Optimal combinations of imperfect objects
We address the question of how to make best use of imperfect objects, such as
defective analog and digital components. We show that perfect, or near-perfect,
devices can be constructed by taking combinations of such defects. Any
remaining objects can be recycled efficiently. In addition to its practical
applications, our `defect combination problem' provides a novel generalization
of classical optimization problems.Comment: 4 pages, 3 figures, minor change
Beklag over niet vervolgen:Het gaat het Openbaar Ministerie om met art. 12 Sv-zaken?
Een aangifte van een strafbaar feit door een burger leidt vaak niet tot een strafvervolging. De officier van justitie kan beslissen dat de zaak niet aan de rechter wordt voorgelegd, maar wordt geseponeerd. Tegen deze beslissing kan de belanghebbende zich op grond van artikel 12 Wetboek van Strafvordering beklagen bij het gerechtshof. Dit boek bevat een verslag van een onderzoek naar de praktijk van deze beklagprocedure en de kwaliteit van het werk van het Openbaar Ministerie. De centrale vraag in het onderzoek is of het werk van het Openbaar Misisterie in de beklagprocedure beantwoordt aan de kwaliteitseisen die daaraan mogen worden gesteld. Relevante informatie is verkregen door een kwantitatieve analyse van beklagzaken over de jaren 2010-2014, een uitvoerig dossieronderzoek en interviews met functionarissen die betrokken zijn bij een afhandeling van beklagzaken
Search for More Declarativity
Good tree search algorithms are a key requirement for inference
engines of rule languages. As Prolog exemplifies, inference engines
based on traditional uninformed search methods with their well-known
deficiencies are prone to compromise declarativity, the primary concern
of rule languages. The paper presents a new family of uninformed search
algorithms that combine the advantages of the traditional ones while
avoiding their shortcomings. Moreover, the paper introduces a formal
framework based on partial orderings, which allows precise and elegant
analysis of such algorithms
Platform Dependent Verification: On Engineering Verification Tools for 21st Century
The paper overviews recent developments in platform-dependent explicit-state
LTL model checking.Comment: In Proceedings PDMC 2011, arXiv:1111.006
The Bioperl toolkit: Perl modules for the life sciences
The Bioperl project is an international open-source collaboration of biologists, bioinformaticians, and computer scientists that has evolved over the past 7 yr into the most comprehensive library of Perl modules available for managing and manipulating life-science information. Bioperl provides an easy-to-use, stable, and consistent programming interface for bioinformatics application programmers. The Bioperl modules have been successfully and repeatedly used to reduce otherwise complex tasks to only a few lines of code. The Bioperl object model has been proven to be flexible enough to support enterprise-level applications such as EnsEMBL, while maintaining an easy learning curve for novice Perl programmers. Bioperl is capable of executing analyses and processing results from programs such as BLAST, ClustalW, or the EMBOSS suite. Interoperation with modules written in Python and Java is supported through the evolving BioCORBA bridge. Bioperl provides access to data stores such as GenBank and SwissProt via a flexible series of sequence input/output modules, and to the emerging common sequence data storage format of the Open Bioinformatics Database Access project. This study describes the overall architecture of the toolkit, the problem domains that it addresses, and gives specific examples of how the toolkit can be used to solve common life-sciences problems. We conclude with a discussion of how the open-source nature of the project has contributed to the development effort
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