Wyniki wyszukiwania - BazTech

1

Sailing vessel routing considering safety zone and penalty time for altering course

Życzkowski M.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2017

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Vol. 11, no. 2

235--240

EN

In this paper we introduce new model for simulation sea vessel routing. Besides a vessel types (polar diagram) and weather forecast, travel security and the number of maneuvers are considered. Based on these data both the minimal travelling costs and the minimal processing time are found for different vessels and different routes. To test our model the applications SailingAssistance wad improved. The obtained results shows that we can obtain quite acceptable results.

2

Dynamic Path Planning with Regular Triangulations

Brož P., Zemek M., Kolingerová I., Szkandera J.

Machine Graphics and Vision

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2014

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Vol. 23, No. 3/4

119--142

EN

Path planning is a well known problem that has been extensively studied in many scientific disciplines. In general, it defines a task of finding a path between two given spots in an abstract environment so that the path satisfies certain criterion of optimality. Although there are many methods solving this objective, they usually assume the examined space does not change in runtime. Modern applications, however, do not have to meet these requirements, especially in case of virtual reality or computer games. Therefore, we propose a general model for real-time path planning in dynamic environment where the obstacles can nondeterministically appear, disappear, change the position, orientation or even shape. The model uses a triangulation for dynamic space subdivision among bounding spheres of the obstacles and a heuristic algorithm to repair an already found path after any change of the scene. The presented solution is the first one using regular triangulation. At the price of the suboptimal result, it provides an efficient and fast way to plan a path with the maximal clearance among the moving and changing obstacles. In comparison to raster based techniques and methods using the Delaunay triangulation (Voronoi diagram), it requires less time to preprocess and generates paths with a larger clearance.

3

The efficiency of the A* algorithm’s implementations in selected programming languages

Klimaszewski J.

Journal of Theoretical and Applied Computer Science

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2014

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Vol. 8, nr 2

63--71

EN

This article presents results of the experiment, in which data structures, used by the A* algorithm (i.e. priority queue and hash table), were tested. A* algorithm was used to solve 15-puzzle, where puzzle’s state was kept in the 64-bit integer variable. The algorithm used either built-in data structures (such as Python’s dictionary) or provided by a standard library (such as unordered map in the C++ Standard Template Library).

4

Using quad tree as data storage for a terrain representation and a core for a path finding algorithm

Waresiak B., Skrzyński P.

Automatyka / Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie

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2011

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T. 15, z. 3

681-691

EN

This paper presents the concept of using single quad tree data structure for data storage for terrain representation and simultaneously a core for a path-finding algorithm. The simulated world is an artificially created two-dimensional world that consists of an island surrounded by water, which is considered to be an impassable terrain. Furthermore, the path-find operation is a possible route for a ship that has to avoid the island. The application of the quad tree data structure for Level of Detail implementation in 3D rendering is also discussed. Implementation details are presented together with initial results. Further research paths are presented in the conclusion.

PL

W artykule zaprezentowana została koncepcja wykorzystania pojedynczego drzewa czwórkowego do reprezentacji terenu oraz poszukiwania optymalnej ścieżki. Zaprezentowane zostało drzewo stworzone dla przykładowego świata, który składa się z wyspy otoczonej wodą, przy czym poruszanie się jest możliwe tylko po wodzie. Ponadto przedyskutowano możliwości zastosowania tego typu struktury do implementacji Level of Detail podczas renderowania kształtów 3D. Poza prezentacją wykorzystywanych w implementacji struktur oraz algorytmów przedstawione są wstępne wyniki oraz zarysowano dalsze kierunki badań.

5

A New Algorithm for Optimal Path Finding in Complex Networks Based on the Quotient Space

Zhang L., He F-g, Zhang Y-p, Zhao S.

Fundamenta Informaticae

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2009

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Vol. 93, nr 4

459-469

EN

The optimal path finding problem in weighted edge networks is an old and interesting one in many fields. There were many well-known algorithms to deal with that issue. But they were confronted with the high computational complexity while the network becoming larger. We present a hierarchical quotient space model based algorithm that reduces the computational complexity. The basic idea is the following. The nodes of a given network are partitioned with respect to the weights of their adjacent edges. We construct a variety of coarser versions of the given network with new nodes corresponding to the blocks of partitions at various levels of granularity. They are called the quotient spaces (networks) of the original network. The construction of the (sub-) optimal path is then done incrementally, throughout the hierarchy of quotient networks. Since each version of the network is much simpler than the original one, especially of the coarsest spaces, the computational complexity is reduced. In this paper, we present the basic principles of the algorithm and its experimental comparison to other well-known algorithms.