143 research outputs found
Improving PARMA Trailing
Taylor introduced a variable binding scheme for logic variables in his PARMA
system, that uses cycles of bindings rather than the linear chains of bindings
used in the standard WAM representation. Both the HAL and dProlog languages
make use of the PARMA representation in their Herbrand constraint solvers.
Unfortunately, PARMA's trailing scheme is considerably more expensive in both
time and space consumption. The aim of this paper is to present several
techniques that lower the cost.
First, we introduce a trailing analysis for HAL using the classic PARMA
trailing scheme that detects and eliminates unnecessary trailings. The
analysis, whose accuracy comes from HAL's determinism and mode declarations,
has been integrated in the HAL compiler and is shown to produce space
improvements as well as speed improvements. Second, we explain how to modify
the classic PARMA trailing scheme to halve its trailing cost. This technique is
illustrated and evaluated both in the context of dProlog and HAL. Finally, we
explain the modifications needed by the trailing analysis in order to be
combined with our modified PARMA trailing scheme. Empirical evidence shows that
the combination is more effective than any of the techniques when used in
isolation.
To appear in Theory and Practice of Logic Programming.Comment: 36 pages, 7 figures, 8 table
Redundant Sudoku Rules
The rules of Sudoku are often specified using twenty seven
\texttt{all\_different} constraints, referred to as the {\em big} \mrules.
Using graphical proofs and exploratory logic programming, the following main
and new result is obtained: many subsets of six of these big \mrules are
redundant (i.e., they are entailed by the remaining twenty one \mrules), and
six is maximal (i.e., removing more than six \mrules is not possible while
maintaining equivalence). The corresponding result for binary inequality
constraints, referred to as the {\em small} \mrules, is stated as a conjecture.Comment: 14 pages, 161 figures, to appear in TPL
Role of circulating biomarkers in spinal muscular atrophy: insights from a new treatment era
Spinal muscular atrophy (SMA) is a lower motor neuron disease due to biallelic mutations in the SMN1 gene on chromosome 5. It is characterized by progressive muscle weakness of limbs, bulbar and respiratory muscles. The disease is usually classified in four different phenotypes (1–4) according to age at symptoms onset and maximal motor milestones achieved. Recently, three disease modifying treatments have received approval from the Food and Drug Administration (FDA) and the European Medicines Agency (EMA), while several other innovative drugs are under study. New therapies have been game changing, improving survival and life quality for SMA patients. However, they have also intensified the need for accurate biomarkers to monitor disease progression and treatment efficacy. While clinical and neurophysiological biomarkers are well established and helpful in describing disease progression, there is a great need to develop more robust and sensitive circulating biomarkers, such as proteins, nucleic acids, and other small molecules. Used alone or in combination with clinical biomarkers, they will play a critical role in enhancing patients’ stratification for clinical trials and access to approved treatments, as well as in tracking response to therapy, paving the way to the development of individualized therapeutic approaches. In this comprehensive review, we describe the foremost circulating biomarkers of current significance, analyzing existing literature on non-treated and treated patients with a special focus on neurofilaments and circulating miRNA, aiming to identify and examine their role in the follow-up of patients treated with innovative treatments, including gene therapy
The divergence time of protein structures modelled by Markov matrices and its relation to the divergence of sequences
A complete time-parameterized statistical model quantifying the divergent
evolution of protein structures in terms of the patterns of conservation of
their secondary structures is inferred from a large collection of protein 3D
structure alignments. This provides a better alternative to time-parameterized
sequence-based models of protein relatedness, that have clear limitations
dealing with twilight and midnight zones of sequence relationships. Since
protein structures are far more conserved due to the selection pressure
directly placed on their function, divergence time estimates can be more
accurate when inferred from structures. We use the Bayesian and
information-theoretic framework of Minimum Message Length to infer a
time-parameterized stochastic matrix (accounting for perturbed structural
states of related residues) and associated Dirichlet models (accounting for
insertions and deletions during the evolution of protein domains). These are
used in concert to estimate the Markov time of divergence of tertiary
structures, a task previously only possible using proxies (like RMSD). By
analyzing one million pairs of homologous structures, we yield a relationship
between the Markov divergence time of structures and of sequences. Using these
inferred models and the relationship between the divergence of sequences and
structures, we demonstrate a competitive performance in secondary structure
prediction against neural network architectures commonly employed for this
task. The source code and supplementary information are downloadable from
\url{http://lcb.infotech.monash.edu.au/sstsum}.Comment: 12 pages, 6 figure
Human-Centred Feasibility Restoration
Decision systems for solving real-world combinatorial problems must be able to report infeasibility in such a way that users can understand the reasons behind it, and understand how to modify the problem to restore feasibility. Current methods mainly focus on reporting one or more subsets of the problem constraints that cause infeasibility. Methods that also show users how to restore feasibility tend to be less flexible and/or problem-dependent. We describe a problem-independent approach to feasibility restoration that combines existing techniques from the literature in novel ways to yield meaningful, useful, practical and flexible user support. We evaluate the resulting framework on two real-world applications
Suppl: A Flexible Language for Policies
Abstract. We present the Simple Unified Policy Programming Lan-guage (Suppl), a domain-neutral language for stating, executing, and analyzing event-condition-action policies. Suppl uses a novel combina-tion of pure logic programming and disciplined imperative programming features to make it easy for non-expert users to express common policy idioms. The language is strongly typed and moded to allow static detec-tion of common programming errors, and it supports a novel logic-based static analysis that can detect internally inconsistent policies. Suppl has been implemented as a compiler to Prolog and used to build several network security applications in a Java framework.
Improving the efficiency of nondeterministic indepemndent and-parallel systems
We present the design and implementation of the and-parallel component of ACE. ACE is a computational model for the full Prolog language that simultaneously exploits both or-parallelism and independent and-parallelism. A high performance implementation of the ACE model has been realized and its performance reported in this paper. We discuss how some of the standard problems which appear when implementing and-parallel systems are solved in ACE. We then propose a number of optimizations aimed at reducing the overheads and the increased memory consumption which occur in such systems when using previously proposed solutions. Finally, we present results from an implementation of ACE which includes the optimizations proposed. The results show that ACE exploits and-parallelism
with high efficiency and high speedups. Furthermore, they also show that the proposed optimizations, which are applicable to many other and-parallel systems, significantly decrease memory consumption and increase speedups and absolute performance both in forwards
execution and during backtracking
Toro Times: Raising Our Voices!
During the Spring 2019 semester, Dr. Noah Asher Golden\u27s Teaching of Writing K-12 students partnered with the Journalism class at Yorba Academy for the Arts. Through collaboration over a four-month period, Chapman\u27s future teachers and Yorba\u27s junior high journalists engaged a deep writing process to write a series of features, editorials, and news articles related to a number of global issues. Thank you to Principal Preciado-Martin, former principal Tracy Knibb, Mrs. Andrea Lopez, Mrs. Kori Shelton, and the Lloyd E. and Elisabeth H. Klein Family Foundation for supporting this project.https://digitalcommons.chapman.edu/yorba-chapman/1004/thumbnail.jp
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