1,506 research outputs found
CHR(PRISM)-based Probabilistic Logic Learning
PRISM is an extension of Prolog with probabilistic predicates and built-in
support for expectation-maximization learning. Constraint Handling Rules (CHR)
is a high-level programming language based on multi-headed multiset rewrite
rules.
In this paper, we introduce a new probabilistic logic formalism, called
CHRiSM, based on a combination of CHR and PRISM. It can be used for high-level
rapid prototyping of complex statistical models by means of "chance rules". The
underlying PRISM system can then be used for several probabilistic inference
tasks, including probability computation and parameter learning. We define the
CHRiSM language in terms of syntax and operational semantics, and illustrate it
with examples. We define the notion of ambiguous programs and define a
distribution semantics for unambiguous programs. Next, we describe an
implementation of CHRiSM, based on CHR(PRISM). We discuss the relation between
CHRiSM and other probabilistic logic programming languages, in particular PCHR.
Finally we identify potential application domains
Irregular alignment of arbitrarily long DNA sequences on GPU
The use of Graphics Processing Units to accelerate computational applications is increasingly being adopted due to its affordability, flexibility and performance. However, achieving top performance comes at the price of restricted data-parallelism models. In the case of sequence alignment, most GPU-based approaches focus on accelerating the Smith-Waterman dynamic programming algorithm due to its regularity. Nevertheless, because of its quadratic complexity, it becomes impractical when comparing long sequences, and therefore heuristic methods are required to reduce the search space. We present GPUGECKO, a CUDA implementation for the sequential, seed-and-extend sequence-comparison algorithm, GECKO. Our proposal includes optimized kernels based on collective operations capable of producing arbitrarily long alignments while dealing with heterogeneous and unpredictable load. Contrary to other state-of-the-art methods, GPUGECKO employs a batching mechanism that prevents memory exhaustion by not requiring to fit all alignments at once into the device memory, therefore enabling to run massive comparisons exhaustively with improved sensitivity while also providing up to 6x average speedup w.r.t. the CUDA acceleration of BLASTN.Funding for open access publishing: Universidad Málaga/CBUA /// This work has been partially supported by the European project ELIXIR-EXCELERATE (grant no. 676559), the Spanish national project Plataforma de Recursos Biomoleculares y Bioinformáticos (ISCIII-PT13.0001.0012 and ISCIII-PT17.0009.0022), the Fondo Europeo de Desarrollo Regional (UMA18-FEDERJA-156, UMA20-FEDERJA-059), the Junta de Andalucía (P18-FR-3130), the Instituto de Investigación Biomédica de Málaga IBIMA and the University of Málaga
The domestic political impact of foreign aid: recalibrating the research agenda
The recent concentration of attention by some political scientists on evaluating the effectiveness of democracy assistance, drawing on the transient policy concerns of major donors, is a welcome innovation to a research agenda traditionally biased towards aid's significance for economic development. But its focus is restricted and unrepresentative. This article argues the case for a more comprehensive assessment of the domestic political consequences - both direct and indirect - of all forms of aid, in principle for aid recipients everywhere. This recommendation offers the advantage of serving the limited purposes of analysts of democratisation generally and democracy aid specifically, but more importantly reconnects their approach with the broader political analysis of aid by a wider social science community. It is important to 'think outside the box' of contemporary donor concerns, recalibrating the research agenda in ways that raise other political priorities. The article offers a framework for this purpose. Comprehending the political dynamics in aid-receiving countries should be the primary orienting principle, rather than viewing countries as objects of aid and proceeding to interpret their politics through the distorting lens of donor perspectives
JGraphT -- A Java library for graph data structures and algorithms
Mathematical software and graph-theoretical algorithmic packages to
efficiently model, analyze and query graphs are crucial in an era where
large-scale spatial, societal and economic network data are abundantly
available. One such package is JGraphT, a programming library which contains
very efficient and generic graph data-structures along with a large collection
of state-of-the-art algorithms. The library is written in Java with stability,
interoperability and performance in mind. A distinctive feature of this library
is the ability to model vertices and edges as arbitrary objects, thereby
permitting natural representations of many common networks including
transportation, social and biological networks. Besides classic graph
algorithms such as shortest-paths and spanning-tree algorithms, the library
contains numerous advanced algorithms: graph and subgraph isomorphism; matching
and flow problems; approximation algorithms for NP-hard problems such as
independent set and TSP; and several more exotic algorithms such as Berge graph
detection. Due to its versatility and generic design, JGraphT is currently used
in large-scale commercial, non-commercial and academic research projects. In
this work we describe in detail the design and underlying structure of the
library, and discuss its most important features and algorithms. A
computational study is conducted to evaluate the performance of JGraphT versus
a number of similar libraries. Experiments on a large number of graphs over a
variety of popular algorithms show that JGraphT is highly competitive with
other established libraries such as NetworkX or the BGL.Comment: Major Revisio
Gatekeepers and lock masters: the control of access in the Neo-Assyrian palaces
Book description: This volume is intended as a tribute to the memory of the Sumerologist Jeremy Black, who died in 2004. The Sumerian phrase, ‘Your praise is sweet’ is commonly addressed to a deity at the close of a work of Sumerian literature. The scope of the thirty contributions, from Sumerology to the nineteenth-century rediscovery of Mesopotamia, is testament to Jeremy’s own wide-ranging interests and to his ability to forge scholarly connections and friendships among all who shared his interest in ancient Iraq
Parallel execution of constraint handling rules - Theory, implementation and application
Ph.DDOCTOR OF PHILOSOPH
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