Gradient-based local optimization has been shown to improve results of genetic programming (GP) for symbolic regression. Several state-of-the-art GP implementations use iterative nonlinear least squares (NLS) algorith...
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Gradient-based local optimization has been shown to improve results of genetic programming (GP) for symbolic regression. Several state-of-the-art GP implementations use iterative nonlinear least squares (NLS) algorithms such as the Levenberg-Marquardt algorithm for local optimization. the effectiveness of NLS algorithms depends on appropriate scaling and conditioning of the optimization problem. this has so far been ignored in symbolic regression and GP literature. In this study we use a singular value decomposition of NLS Jacobian matrices to determine the numeric rank and the condition number. We perform experiments with a GP implementation and six different benchmark datasets. Our results show that rank-deficient and ill-conditioned Jacobian matrices occur frequently and for all datasets. the issue is less extreme when restricting GP tree size and when using many non-linear functions in the function set.
We introduce Venn diagrams for multisets and showhow they simplify the analysis of multisets. Venn diagrams arevery useful in proofs involving multisets and multiset orders, especially considering the complications in...
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We introduce Venn diagrams for multisets and showhow they simplify the analysis of multisets. Venn diagrams arevery useful in proofs involving multisets and multiset orders, especially considering the complications introduced by the multiplicity of elements in multisets. We compare the Venn diagramsfor multisets withthe corresponding ones for sets. thus, wepresent two types of Venn diagrams for multisets, a simple onethat looks like a diagram for sets, but with areas that are notnecessarily disjoint, and a complex one (compared to sets), butwith certain delimited disjoint areas.
We define the functional inverse of the Gamma function. It is a multivalued function, and we define its branches. We present its basic properties, included series approximations, asymptotic results and numerical evalu...
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ISBN:
(纸本)9781538626276
We define the functional inverse of the Gamma function. It is a multivalued function, and we define its branches. We present its basic properties, included series approximations, asymptotic results and numerical evaluation.
the development of software systems for scientific exploration and discovery through computation has an important issue to address: the management of underlying computational steps. To support composition of Web and G...
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the development of software systems for scientific exploration and discovery through computation has an important issue to address: the management of underlying computational steps. To support composition of Web and Grid services, standard workflow languages and workflow execution engines were built but management capabilities are not yet entirely explored. In the context of Grid services, we propose a solution for controlling the execution of workflows without the assistance of a user interface oriented workflow engine. We also investigate the capabilities that our solution may offer for related features such as dynamic retrieval of partial results, steering and provenance.
ROC! is a deterministic rewrite strategy language which includes the rewrite rules as basic operators, and the deterministic choice and the repetition as high-level strategy operators. In this paper we present a metho...
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ROC! is a deterministic rewrite strategy language which includes the rewrite rules as basic operators, and the deterministic choice and the repetition as high-level strategy operators. In this paper we present a method which, for a given term Rewriting system (TRS) R, constructs a new TRS Rmacr such that R-rewriting is equivalent (sound and complete) with Rmacr-rewriting constrained by ROC!. Since Rmacr uses a stack, it is called a rewrite stack machine.
Data compression is used to reduce the cost of storing and transmitting increasingly large datasets in various domains ranging from bioinformatics to particle physics and general purpose computing. Most of these areas...
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Data compression is used to reduce the cost of storing and transmitting increasingly large datasets in various domains ranging from bioinformatics to particle physics and general purpose computing. Most of these areas require the ability to scan the datasets for patterns like DNA sequences, malicious executable code or various other string queries, an operation that is hindered by the altered form of the data. In order to speed up the matching process, several compressed pattern matching algorithms have been previously proposed. this paper presents an overview of the state of the art in multiple pattern matching of Lempel-Ziv-Welch encoded archives, together with experimental results.
Learning and backjumping are essential features in search-based decision procedures for Quantified Boolean Formulas (QBF). To obtain a better understanding of such procedures, we present a formal framework, which allo...
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ISBN:
(纸本)9781509057085
Learning and backjumping are essential features in search-based decision procedures for Quantified Boolean Formulas (QBF). To obtain a better understanding of such procedures, we present a formal framework, which allows to simultaneously reason on prenex conjunctive and disjunctive normal form. It captures both satisfying and falsifying search states in a symmetric way. this symmetry simplifies the framework and offers potential for further variants.
We describe arithmetic computations in terms of operations on some well known free algebras (S1S, S2S and ordered rooted binary trees) while emphasizing the common structure present in all of them when seen as isomorp...
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We describe arithmetic computations in terms of operations on some well known free algebras (S1S, S2S and ordered rooted binary trees) while emphasizing the common structure present in all of them when seen as isomorphic withthe set of natural numbers. Constructors and deconstructors seen through an initial algebra semantics are generalized to recursively defined functions obeying similar laws. Implementations using GHC's "view" construct are discussed, based on the free algebra of rooted ordered binary trees.
We describe an approach for empirical modeling of steel phase kinetics based on symbolic regression and genetic programming. the algorithm takes processed data gathered from dilatometer measurements and produces a sys...
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We describe an approach for empirical modeling of steel phase kinetics based on symbolic regression and genetic programming. the algorithm takes processed data gathered from dilatometer measurements and produces a system of differential equations that models the phase kinetics. Our initial results demonstrate that the proposed approach allows to identify compact differential equations that fit the data. the model predicts ferrite, pearlite and bainite formation for a single steel type. Martensite is not yet included in the model. Future work shall incorporate martensite and generalize to multiple steel types with different chemical compositions.
Resource scheduling based on SLA (Service Level Agreement) in cloud computing is NP-hard problem. there is no efficient method to solve it. this paper proposes a new method to solve the problem by applying stochastic ...
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Resource scheduling based on SLA (Service Level Agreement) in cloud computing is NP-hard problem. there is no efficient method to solve it. this paper proposes a new method to solve the problem by applying stochastic integer programming for optimal resource scheduling in cloud computing. Applying Gröbner bases theory for solving the stochastic integer programming problem and the experimental results of the implementation are also presented.
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