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Wyświetlanie 1-11 z 11
Tytuł:
Tabu search for the RNA partial degradation problem
Autorzy:
Rybarczyk, A.
Hertz, A.
Kasprzak, M.
Blazewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/330324.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
RNA degradation
tabu search
bioinformatics
rozkład RNA
algorytm tabu search
bioinformatyka
Opis:
In recent years, a growing interest has been observed in research on RNA (ribonucleic acid), primarily due to the discovery of the role of RNA molecules in biological systems. They not only serve as templates in protein synthesis or as adapters in the translation process, but also influence and are involved in the regulation of gene expression. The RNA degradation process is now heavily studied as a potential source of such riboregulators. In this paper, we consider the so-called RNA partial degradation problem (RNA PDP). By solving this combinatorial problem, one can reconstruct a given RNA molecule, having as input the results of the biochemical analysis of its degradation, which possibly contain errors (false negatives or false positives). From the computational point of view the RNA PDP is strongly NP-hard. Hence, there is a need for developing algorithms that construct good suboptimal solutions. We propose a heuristic approach, in which two tabu search algorithms cooperate, in order to reconstruct an RNA molecule. Computational tests clearly demonstrate that the proposed approach fits well the biological problem and allows to achieve near-optimal results. The algorithm is freely available at http://www.cs.put.poznan.pl/arybarczyk/tabusearch.php.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2017, 27, 2; 401-415
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A support vector machine with the tabu search algorithm for freeway incident detection
Autorzy:
Yao, B.
Hu, P.
Zhang, M.
Jin, M.
Powiązania:
https://bibliotekanauki.pl/articles/329943.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
automated incident detection
support vector machine (SVM)
tabu search
freeway
maszyna wektorów wspierających
odcinek swobodny trasy
algorytm tabu search
Opis:
Automated Incident Detection (AID) is an important part of Advanced Traffic Management and Information Systems (ATMISs). An automated incident detection system can effectively provide information on an incident, which can help initiate the required measure to reduce the influence of the incident. To accurately detect incidents in expressways, a Support Vector Machine (SVM) is used in this paper. Since the selection of optimal parameters for the SVM can improve prediction accuracy, the tabu search algorithm is employed to optimize the SVM parameters. The proposed model is evaluated with data for two freeways in China. The results show that the tabu search algorithm can effectively provide better parameter values for the SVM, and SVM models outperform Artificial Neural Networks (ANNs) in freeway incident detection.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2014, 24, 2; 397-404
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heuristic algorithms for joint optimization of unicast and anycast traffic in elastic optical network-based large-scale computing systems
Autorzy:
Markowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/330713.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
elastic optical network
joint optimization
distributed data center
metaheuristic algorithm
tabu search
elastyczna sieć optyczna
optymalizacja wspólna
baza danych rozproszona
algorytm heurystyczny
metoda tabu search
Opis:
In recent years elastic optical networks have been perceived as a prospective choice for future optical networks due to better adjustment and utilization of optical resources than is the case with traditional wavelength division multiplexing networks. In the paper we investigate the elastic architecture as the communication network for distributed data centers. We address the problems of optimization of routing and spectrum assignment for large-scale computing systems based on an elastic optical architecture; particularly, we concentrate on anycast user to data center traffic optimization. We assume that computational resources of data centers are limited. For this offline problems we formulate the integer linear programming model and propose a few heuristics, including a meta-heuristic algorithm based on a tabu search method. We report computational results, presenting the quality of approximate solutions and efficiency of the proposed heuristics, and we also analyze and compare some data center allocation scenarios.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2017, 27, 3; 605-622
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Automatic parametric fault detection in complex analog systems based on a method of minimum node selection
Autorzy:
Bilski, A.
Wojciechowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/330761.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
complex analog system
support vector machine (SVM)
tabu search
genetic algorithm
parametric fault detection
system analogowy
maszyna wektorów wspierających
metoda tabu search
algorytm genetyczny
detekcja uszkodzeń
Opis:
The aim of this paper is to introduce a strategy to find a minimal set of test nodes for diagnostics of complex analog systems with single parametric faults using the support vector machine (SVM) classifier as a fault locator. The results of diagnostics of a video amplifier and a low-pass filter using tabu search along with genetic algorithms (GAs) as node selectors in conjunction with the SVM fault classifier are presented. General principles of the diagnostic procedure are first introduced, and then the proposed approach is discussed in detail. Diagnostic results confirm the usefulness of the method and its computational requirements. Conclusions on its wider applicability are provided as well.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2016, 26, 3; 655-668
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Derivative-free nonlinear optimization filter simplex
Autorzy:
Correia, A.
Matias, J.
Mestre, P.
Serodio, C.
Powiązania:
https://bibliotekanauki.pl/articles/908145.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
optymalizacja nieliniowa
optymalizacja ograniczona
metoda filtru
nonlinear constrained optimization
filter methods
direct search methods
Opis:
The filter method is a technique for solving nonlinear programming problems. The filter algorithm has two phases in each iteration. The first one reduces a measure of infeasibility, while in the second the objective function value is reduced. In real optimization problems, usually the objective function is not differentiable or its derivatives are unknown. In these cases it becomes essential to use optimization methods where the calculation of the derivatives or the verification of their existence is not necessary: direct search methods or derivative-free methods are examples of such techniques. In this work we present a new direct search method, based on simplex methods, for general constrained optimization that combines the features of simplex and filter methods. This method neither computes nor approximates derivatives, penalty constants or Lagrange multipliers.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2010, 20, 4; 679-688
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two meta-heuristic algorithms for scheduling on unrelated machines with the late work criterion
Autorzy:
Wang, Wen
Chen, Xin
Musial, Jędrzej
Blazewicz, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/330022.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
late work minimization
unrelated machines
tabu search
genetic algorithm
minimalizacja opóźnienia
przeszukiwanie tabu
algorytm genetyczny
Opis:
A scheduling problem in considered on unrelated machines with the goal of total late work minimization, in which the late work of a job means the late units executed after its due date. Due to the NP-hardness of the problem, we propose two meta-heuristic algorithms to solve it, namely, a tabu search (TS) and a genetic algorithm (GA), both of which are equipped with the techniques of initialization, iteration, as well as termination. The performances of the designed algorithms are verified through computational experiments, where we show that the GA can produce better solutions but with a higher time consumption. Moreover, we also analyze the influence of problem parameters on the performances of these metaheuristics.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2020, 30, 3; 573-584
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numbering action vertices in workflow graphs
Autorzy:
Mann, Z. Á.
Powiązania:
https://bibliotekanauki.pl/articles/929577.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
wykres przepływu pracy
sieć przepływu
numeracja
przeszukiwanie w głąb
workflow graph
flowchart
event-driven process chain
numbering
depth-first search
Opis:
Workflow graphs, consisting of actions, events, and logical switches, are used to model business processes. In order to easily identify the actions within a workflow graph, it is useful to number them in such a way that the numbering reflects the structure of the workflow. However, available tools offer only rudimental numbering schemes. In the paper, a set of natural requirements is defined that a logical numbering should fulfill. It is investigated under what conditions there is an appropriate numbering at all, when it is uniquely defined by the set of requirements, and when it can be computed efficiently. It is shown that for an important special class of workflow graphs, namely, structured workflow graphs, the answer to all these questions is affirmative. For general workflow graphs, a set of requirements is presented that can always be fulfilled, but the numbering is not necessarily unique. An algorithm based on a depth-first search can be used to compute an appropriate numbering efficiently.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2010, 20, 3; 591-600
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
D* Extra Lite: A dynamic A* with search-tree cutting and frontier-gap repairing
Autorzy:
Przybylski, M.
Putz, B.
Powiązania:
https://bibliotekanauki.pl/articles/329769.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
shortest path planning
incremental heuristic search
mobile robot navigation
video game
planowanie najkrótszej ścieżki
wyszukiwanie heurystyczne
nawigacja robota mobilnego
gra wideo
Opis:
Searching for the shortest-path in an unknown or changeable environment is a common problem in robotics and video games, in which agents need to update maps and to perform re-planning in order to complete their missions. D* Lite is a popular incremental heuristic search algorithm (i.e., it utilizes knowledge from previous searches). Its efficiency lies in the fact that it re-expands only those parts of the search-space that are relevant to registered changes and the current state of the agent. In this paper, we propose a new D* Extra Lite algorithm that is close to a regular A*, with reinitialization of the affected search-space achieved by search-tree branch cutting. The provided worst-case complexity analysis strongly suggests that D* Extra Lite’s method of reinitialization is faster than the focused approach to reinitialization used in D* Lite. In comprehensive tests on a large number of typical two-dimensional path-planning problems, D* Extra Lite was 1.08 to 1.94 times faster than the optimized version of D* Lite. Moreover, while demonstrating that it can be particularly suitable for difficult, dynamic problems, as the problem-complexity increased, D* Extra Lite’s performance further surpassed that of D*Lite. The source code of the algorithm is available on the open-source basis.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2017, 27, 2; 273-290
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A metaheuristic for a numerical approximation to the mass transfer problem
Autorzy:
Avendaño-Garrido, M. L.
Gabriel-Argüelles, J. R.
Quintana-Torres, L.
Mezura-Montes, E.
Powiązania:
https://bibliotekanauki.pl/articles/329972.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
Monge–Kantorovich mass transfer problem
finite dimensional linear programming
transport problem
metaheuristic algorithm
scatter search
programowanie skończenie wymiarowe
zadanie transportowe
algorytm metaheurystyczny
Opis:
This work presents an improvement of the approximation scheme for the Monge–Kantorovich (MK) mass transfer problem on compact spaces, which is studied by Gabriel et al. (2010), whose scheme discretizes the MK problem, reduced to solve a sequence of finite transport problems. The improvement presented in this work uses a metaheuristic algorithm inspired by scatter search in order to reduce the dimensionality of each transport problem. The new scheme solves a sequence of linear programming problems similar to the transport ones but with a lower dimension. The proposed metaheuristic is supported by a convergence theorem. Finally, examples with an exact solution are used to illustrate the performance of our proposal.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2016, 26, 4; 757-766
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Efficient astronomical data condensation using approximate nearest neighbors
Autorzy:
Łukasik, Szymon
Lalik, Konrad
Sarna, Piotr
Kowalski, Piotr A.
Charytanowicz, Małgorzata
Kulczycki, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/907932.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
big data
astronomical observation
data reduction
nearest neighbor search
kd-trees
duży zbiór danych
obserwacja astronomiczna
redukcja danych
wyszukiwanie najbliższego sąsiada
drzewo kd
Opis:
Extracting useful information from astronomical observations represents one of the most challenging tasks of data exploration. This is largely due to the volume of the data acquired using advanced observational tools. While other challenges typical for the class of big data problems (like data variety) are also present, the size of datasets represents the most significant obstacle in visualization and subsequent analysis. This paper studies an efficient data condensation algorithm aimed at providing its compact representation. It is based on fast nearest neighbor calculation using tree structures and parallel processing. In addition to that, the possibility of using approximate identification of neighbors, to even further improve the algorithm time performance, is also evaluated. The properties of the proposed approach, both in terms of performance and condensation quality, are experimentally assessed on astronomical datasets related to the GAIA mission. It is concluded that the introduced technique might serve as a scalable method of alleviating the problem of the dataset size.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2019, 29, 3; 467-476
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Accelerating backtrack search with a best-first-search strategy
Autorzy:
Mann, Z. Á.
Szép, T.
Powiązania:
https://bibliotekanauki.pl/articles/329816.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
best first search
backtrack
branch and bound
constraint satisfaction problem (CSP)
frequent restarting
algorytm wyszukiwania
system backtrack
metoda podziału i ograniczeń
programowanie z ograniczeniami
Opis:
Backtrack-style exhaustive search algorithms for NP-hard problems tend to have large variance in their runtime. This is because “fortunate” branching decisions can lead to finding a solution quickly, whereas “unfortunate” decisions in another run can lead the algorithm to a region of the search space with no solutions. In the literature, frequent restarting has been suggested as a means to overcome this problem. In this paper, we propose a more sophisticated approach: a best-first-search heuristic to quickly move between parts of the search space, always concentrating on the most promising region. We describe how this idea can be efficiently incorporated into a backtrack search algorithm, without sacrificing optimality. Moreover, we demonstrate empirically that, for hard solvable problem instances, the new approach provides significantly higher speed-up than frequent restarting.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2014, 24, 4; 901-916
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-11 z 11

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