Wyniki wyszukiwania - BazTech

1

Development the methods of optimum placement undirected planar objects with piecewise non-linear boundaries in the multiply area

Chaplya Yu., Sobol O.

ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes

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2016

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Vol. 5, No 2

39--44

EN

In this paper the statement of the problem is formulated and the mathematical model of optimization the placement of the undirected planar geometrical objects with piecewise non-linear boundaries in the multiply area is developed. It is shown the geometrical interpretation and derived the estimate of the number of restrictions in the model. On the basis of a mathematical model for finding the global extremum of the objective function was proposed modified method of branches and boundaries. It is also shown the solutions tree that takes into account the problems of optimal placement of undirected planar geometrical object with piecewise nonlinear boundaries in the multiply area, and received the complexity of this method. For locally optimal solutions of the problem modified simulated annealing method has been developed. Thus the analytical expressions for the function of energy system were received, the function, that describes the decrease of temperature over time, function that forms a new state of system. The method of formation the new state of the system was investigated in more detail, which is based on a random permutation of numbers the pair of the objects, it is also based on a consistent placement of objects according to reshuffle their numbers and determining the probability of transition to a new state. It is shown the example of determining permissible points of placement the local coordinate system of the specific geometrical object. The conclusion is that to solve practical optimization problems of placement of the undirected planar geometrical objects with piecewise non-linear boundaries in the multiply area should be used the modified simulated annealing method.

2

Branch and Bound method for binary problems with the procedure that reduces dimension of problems

Chudy M.

Computer Science and Mathematical Modelling

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2016

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No. 4

13--18

EN

The relationships between elements of coefficient matrix, elements of vector and elements of vector in general binary problem are considered. Some of them allow us to establish the values of selected elements of feasible or optimal vector . This procedure reduces the dimension of basic problem and can be install in branch and bound method. It gives positive effects.

PL

Przedstawiono kilka własności problemów binarnych, które pozwalają redukować wymiar zadania poprzez wyszukiwanie i ustalanie wartości niektórych zmiennych. W dopuszczalnych wektorach binarnych danego zadania wartości te muszą być przyjęte. Procedurę wykorzystującą te własności wmontowano w metodę podziału i oszacowań, w szczególności do algorytmu przeglądu pośredniego dla zadań binarnych.

3

The branch-and-bound method and genetic algorithm in avoidance of ships collisions in fuzzy environment

Mostefa Mohamed-Seghir Mostefa

Polish Maritime Research

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2012

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S 1

45-49

EN

Marine navigation consists in continuous observation of the situation at sea, determination the anti-collision manoeuvre. So it necessary to determine ship safe trajectory as a sequence of ship course changing manoeuvres. Each manoeuvre is undertaken on the basis of information obtained from the anti-collision system ARPA. This paper describes a method of safe ship control in the collision situation in a fuzzy environment based on a branch and bound method and a genetic algorithm. The optimal safe ship trajectory in a collision situation is presented as multistage decision-making process.

4

On probabilistic bounds inspired by interval arithmetic

Zilinskas A., Zilinskas J.

Control and Cybernetics

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2010

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Vol. 39, no 2

507-525

EN

A randomized method aimed at evaluation of probabilistic bounds for function values is considered. Stochastic intervals tightly covering ranges of function values with probability close to one are modelled by a randomized method inspired by interval arithmetic. Statistical properties of the modelled intervals are investigated experimentally. The experimental results are discussed with respect to application of this method in the construction of a branch and bound type randomized algorithm for global optimization.

5

Przyspieszanie metody podziału i ograniczeń dla problemu podziału funkcjonalności na sprzęt i oprogramowanie

Strachacki M.

Zeszyty Naukowe Wydziału ETI Politechniki Gdańskiej. Technologie Informacyjne

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2008

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T. 15

55-60

PL

Niniejsza praca przedstawia analizę wrażliwości metody podziału i ograniczeń B&B (ang. branch and bound) używanej do podziału funkcjonalności na sprzęt i oprogramowanie. Zbadano teoretyczny wpływ wszystkich parametrów B&B na czas obliczeń. Wyniki eksperymentów ujawniły, że najwrażliwszymi parametrami są: funkcja ograniczenia dolnego, reguła wyboru podproblemu, reguła podziału oraz rozwiązanie początkowe. Aby skrócić czas obliczeń metody B&B należy odpowiednio zoptymalizować parametry przy użyciu algorytmu symulowane-go wyżarzania. Testy wykazały, że dla rozmiaru problemu n = 30 uzyskano średnio 130-krotne przyspieszenie obliczeń. Opisana optymalizacja hybrydowa jest najwydajniejszą z metod dotychczas zaprezentowanych w literaturze.

EN

This paper presents sensitivity analysis of branch and bound (B&B) method used for hardware/software partitioning task. The impact of all B&B parameters on computation time is theoretically analyzed and results of experiments are presented. Results show that most sensitive parameters are a lower bound function, a selection rule, a branching rule and an initial solution. To shorten B&B computation time these parameters have to be set properly and additional preoptimization step should be applied. This pre-optimization step uses simulated annealing to set parameters in limited time. Results of experiments show that the computation time speedup x 130 is achieved on average. This hybrid optimization is the most efficient presented so far.

6

Harmonogramowanie produkcji w systemie gniazdowym z ograniczoną dostępnością maszyn: blokowa metoda podziału i ograniczeń

Gajoszek E., Książek R., Kaczmarczyk W.

Zeszyty Naukowe. Automatyka / Politechnika Śląska

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2008

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z. 151

111-117

PL

W pracy przedstawiono blokową metodę podziału i ograniczeń do minimalizacji maksymalnej nieterminowości Lmax dla ogólnego zagadnienia gniazdowego z ograniczoną dostępnością maszyn i z podziałem partii. Zadanie sformułowano na potrzeby firmy produkującej części lotnicze. W pracy przedstawiono wyniki obliczeń dla kilkunastu kolejnych tygodni produkcji.

EN

In this paper is presented a branch and bound algorithm using block properties to minimize maximal lateness Z,max in the general job shop scheduling problem with limited machine availability and lot splitting. This method has been implemented for some company producing aircraft parts. This paper presents results of scheduling for several consecutive weeks of production.