Exact Methods for PDEs

2021 ◽  
pp. 303-370
Author(s):  
Daniel Zwillinger ◽  
Vladimir Dobrushkin
Keyword(s):  
Exact Methods

Structures in the Universe by Exact Methods

2009 ◽  
Author(s):  
Krzysztof Bolejko ◽  
Andrzej Krasinski ◽  
Charles Hellaby ◽  
Marie-Noelle Celerier
Keyword(s):  
Exact Methods ◽  
The Universe

EXACT METHODS OF LINEAR PROGRAMMING FOR CHOOSING ROCK FAILURE CONDITIONS.

2013 ◽  
Vol 7 (11) ◽  
pp. 52-57
Author(s):  
Oleg Markovich Terentiev ◽  
◽  
Anton Iosifovich Kleshchov ◽  
Keyword(s):  
Linear Programming ◽  
Rock Failure ◽  
Exact Methods ◽  
Failure Conditions

Study of potential curves by UHF type methods. CH4 molecule and its dissociation products

1986 ◽  
Vol 51 (4) ◽  
pp. 731-737
Author(s):  
Viliam Klimo ◽  
Jozef Tiňo
Keyword(s):  
Experimental Data ◽  
Quantum Chemistry ◽  
High Energy ◽  
Basis Set ◽  
Electronic Correlation ◽  
Exact Methods ◽  
Energy Parameters ◽  
Bond Functions ◽  
The Individual ◽  
Potential Curves

Geometry and energy parameters of the individual dissociation intermediate steps of CH4 molecule, parameters of the barrier to linearity and singlet-triplet separation of the CH2 molecule have been calculated by means of the UMP method in the minimum basis set augmented with the bond functions. The results agree well with experimental data except for the geometry of CH2(1A1) and relatively high energy values of CH(2II) and CH2(1A1) where the existence of two UHF solutions indicates a necessity of description of the electronic correlation by more exact methods of quantum chemistry.

scholarly journals Density Guarantee on Finding Multiple Subgraphs and Subtensors

2021 ◽  
Vol 15 (5) ◽  
pp. 1-32
Author(s):  
Quang-huy Duong ◽  
Heri Ramampiaro ◽  
Kjetil Nørvåg ◽  
Thu-lan Dam
Keyword(s):  
Lower Bound ◽  
State Of The Art ◽  
The State ◽  
The Other ◽  
Exact Methods ◽  
Practical Solution ◽  
Novel Approach ◽  
Wide Range ◽  
Real World Datasets ◽  
Tensor Data

Dense subregion (subgraph & subtensor) detection is a well-studied area, with a wide range of applications, and numerous efficient approaches and algorithms have been proposed. Approximation approaches are commonly used for detecting dense subregions due to the complexity of the exact methods. Existing algorithms are generally efficient for dense subtensor and subgraph detection, and can perform well in many applications. However, most of the existing works utilize the state-or-the-art greedy 2-approximation algorithm to capably provide solutions with a loose theoretical density guarantee. The main drawback of most of these algorithms is that they can estimate only one subtensor, or subgraph, at a time, with a low guarantee on its density. While some methods can, on the other hand, estimate multiple subtensors, they can give a guarantee on the density with respect to the input tensor for the first estimated subsensor only. We address these drawbacks by providing both theoretical and practical solution for estimating multiple dense subtensors in tensor data and giving a higher lower bound of the density. In particular, we guarantee and prove a higher bound of the lower-bound density of the estimated subgraph and subtensors. We also propose a novel approach to show that there are multiple dense subtensors with a guarantee on its density that is greater than the lower bound used in the state-of-the-art algorithms. We evaluate our approach with extensive experiments on several real-world datasets, which demonstrates its efficiency and feasibility.

A Critique and Improvement of the CL Common Language Effect Size Statistics of McGraw and Wong

2000 ◽  
Vol 25 (2) ◽  
pp. 101-132 ◽  
Author(s):  
András Vargha ◽  
Harold D. Delaney
Keyword(s):  
Effect Size ◽  
Continuous Distribution ◽  
Interval Estimation ◽  
Continuous Variable ◽  
Common Language ◽  
Exact Methods ◽  
Normal Distributions ◽  
The Difference ◽  
Discrete Values ◽  
Two Populations

McGraw and Wong (1992) described an appealing index of effect size, called CL, which measures the difference between two populations in terms of the probability that a score sampled at random from the first population will be greater than a score sampled at random from the second. McGraw and Wong introduced this "common language effect size statistic" for normal distributions and then proposed an approximate estimation for any continuous distribution. In addition, they generalized CL to the n-group case, the correlated samples case, and the discrete values case. In the current paper a different generalization of CL, called the A measure of stochastic superiority, is proposed, which may be directly applied for any discrete or continuous variable that is at least ordinally scaled. Exact methods for point and interval estimation as well as the significance tests of the A = .5 hypothesis are provided. New generalizations ofCL are provided for the multi-group and correlated samples cases.

On a Vector Space Representation in Genetic Algorithms for Sensor Scheduling in Wireless Sensor Networks

2014 ◽  
Vol 22 (3) ◽  
pp. 361-403 ◽  
Author(s):  
F. V. C. Martins ◽  
E. G. Carrano ◽  
E. F. Wanner ◽  
R. H. C. Takahashi ◽  
G. R. Mateus ◽  
...  
Keyword(s):  
Fitness Landscape ◽  
Combinatorial Problem ◽  
Wireless Sensor ◽  
Space Representation ◽  
Network Dynamic ◽  
Decision Variable ◽  
Exact Methods ◽  
Variable Space ◽  
Combinatorial Space ◽  
Evolutionary Operators

Recent works raised the hypothesis that the assignment of a geometry to the decision variable space of a combinatorial problem could be useful both for providing meaningful descriptions of the fitness landscape and for supporting the systematic construction of evolutionary operators (the geometric operators) that make a consistent usage of the space geometric properties in the search for problem optima. This paper introduces some new geometric operators that constitute the realization of searches along the combinatorial space versions of the geometric entities descent directions and subspaces. The new geometric operators are stated in the specific context of the wireless sensor network dynamic coverage and connectivity problem (WSN-DCCP). A genetic algorithm (GA) is developed for the WSN-DCCP using the proposed operators, being compared with a formulation based on integer linear programming (ILP) which is solved with exact methods. That ILP formulation adopts a proxy objective function based on the minimization of energy consumption in the network, in order to approximate the objective of network lifetime maximization, and a greedy approach for dealing with the system's dynamics. To the authors’ knowledge, the proposed GA is the first algorithm to outperform the lifetime of networks as synthesized by the ILP formulation, also running in much smaller computational times for large instances.

An M/M/C/K queueing system in an inventory routing problem considering congestion and response time for post-disaster humanitarian relief: a case study

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mahdieh Masoumi ◽  
Amir Aghsami ◽  
Mohammad Alipour-Vaezi ◽  
Fariborz Jolai ◽  
Behdad Esmailifar
Keyword(s):  
Sensitivity Analyses ◽  
Inventory Routing ◽  
Humanitarian Relief ◽  
Exact Methods ◽  
Routing Problem ◽  
Content Type ◽  
Inventory Routing Problem ◽  
The People ◽  
Proposed Model

PurposeDue to the randomness and unpredictability of many disasters, it is essential to be prepared to face difficult conditions after a disaster to reduce human casualties and meet the needs of the people. After the disaster, one of the most essential measures is to deliver relief supplies to those affected by the disaster. Therefore, this paper aims to assign demand points to the warehouses as well as routing their related relief vehicles after a disaster considering convergence in the border warehouses.Design/methodology/approachThis research proposes a multi-objective, multi-commodity and multi-period queueing-inventory-routing problem in which a queuing system has been applied to reduce the congestion in the borders of the affected zones. To show the validity of the proposed model, a small-size problem has been solved using exact methods. Moreover, to deal with the complexity of the problem, a metaheuristic algorithm has been utilized to solve the large dimensions of the problem. Finally, various sensitivity analyses have been performed to determine the effects of different parameters on the optimal response.FindingsAccording to the results, the proposed model can optimize the objective functions simultaneously, in which decision-makers can determine their priority according to the condition by using the sensitivity analysis results.Originality/valueThe focus of the research is on delivering relief items to the affected people on time and at the lowest cost, in addition to preventing long queues at the entrances to the affected areas.

Evaluating the sufficiency of proposed security measures in favour of building objects

2021 ◽  
Vol 12 (1) ◽  
pp. 66-66
Author(s):  
Josef Reitšpís ◽  
Jozefína Drotárová
Keyword(s):  
Limited Area ◽  
Security Measures ◽  
Exact Methods ◽  
Technical Standards ◽  
Security Environment ◽  
Intentional Actions ◽  
Protection Systems ◽  
Level Of Knowledge ◽  
Satisfactory Answer

Security is understood as one of the basic life needs of people. However, it is necessary to realize that security is a natural quality of the environment where people live and is designated as a security environment. The need for sacurity is part of implementing sacurity measures that are created in compliance with a certain level of knowledge and needs. The content of this process can be characterized as a set of answers to primary questions (What is to be protected? – protected interest, Why to protect?, What to protect from? – threats) and secondary questions (Who will provide the protection?, How will the protection be provided?, When will the protection be provided?, By means of what will the protection be provided?, What price will the protection be provided for? etc.). From this viewpoint it is necessary to pay attention primarily to the problems concerning property protection from intentional actions focusing on protecting a particular building onject. In case of building objects it is primarily about the protection of tangible and intangible properties that are part of a particular limited area (mostly a building object) that is in possession or administration of a particular state or a private subject. The issues are dealt with by legal regulations, technical standards and various technical books. These usually concentrate on a particular area, kind of a building object and/or environment. However, none of them focuses on the property protection in a complex way and does not provide a satisfactory answer to the question "How to create protection systems in view of their sufficiency, complexity and balance in the technical and economic spheres?" That is why it is a social interest to search for new standardized procedures based on exact methods by means of which it will be possible, in empiric or intuitive ways, to exactly evaluate the effectivness of the existing or proposed property protection systems, including the formal desposition of results in project solutions Keywords: Project, Project documentation, Attack, Intervention and Detection time, Resistance of a building object, Modeling, Simulating

scholarly journals Advances in vehicle routing and logistics optimization: exact methods

2019 ◽  
Vol 8 (2) ◽  
pp. 117-118
Author(s):  
Michael Schneider ◽  
Timo Gschwind ◽  
Daniele Vigo
Keyword(s):  
Vehicle Routing ◽  
Exact Methods ◽  
Logistics Optimization
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