Browsing by Subject "Time complexity"

Filter results by typing the first few letters
Now showing 1 - 3 of 3
  • Thumbnail Image
    ItemOpen Access
    An approximation algorithm for computing the visibility region of a point on a terrain and visibility testing
    (IEEE, 2014-01) Alipour, S.; Ghodsi, M.; Güdükbay, Uğur; Golkari, M.
    Given a terrain and a query point p on or above it, we want to count the number of triangles of terrain that are visible from p. We present an approximation algorithm to solve this problem. We implement the algorithm and then we run it on the real data sets. The experimental results show that our approximation solution is very close to the real solution and compare to the other similar works, the running time of our algorithm is better than their algorithm. The analysis of time complexity of algorithm is also presented. Also, we consider visibility testing problem, where the goal is to test whether p and a given triangle of train are visible or not. We propose an algorithm for this problem and show that the average running time of this algorithm will be the same as running time of the case where we want to test the visibility between two query point p and q.
  • Thumbnail Image
    ItemOpen Access
    İmge işleme yoluyla çubuk kod yersenimi
    (IEEE, 2005-05) Öktem, R.; Çetin, A. Enis
    Bu özette imge işleme kullanılarak çubuk kod bölgesi çıkarımı ele alınmıştır. Çubuk kodlar birbirine paralel açık-koyu doğrulardan oluştuklarından, ikili bir ayrıt haritasında da belirli bir oryantasyonda birbirine bağlı paralel doğrular olarak ayırdedilirler. Sunulan algoritmalar, bu özellikten yola çıkarak morfoloji ve serbest açı eşiklemesi yolu ile bar koda ait bölgeyi yersemeyi amaçlamaktadır. Ayrıt haritası oluşturmada Sobel işlemi ve ikili altbant dönüşümü kullanılmakta ve her iki yöntem de zaman karmaşıklığı ve performans açısından karşılaştırılmaktadır.
  • Thumbnail Image
    ItemOpen Access
    Online bicriteria load balancing using object reallocation
    (Institute of Electrical and Electronics Engineers, 2009-03) Tse, S. S. H.
    We study the bicriteria load balancing problem on two independent parameters under the allowance of object reallocation. The scenario is a system of $M$ distributed file servers located in a cluster, and we propose three online approximate algorithms for balancing their loads and required storage spaces during document placement. The first algorithm is for heterogeneous servers. Each server has its individual tradeoff of load and storage space under the same rule of selection. The other two algorithms are for homogeneous servers. The second algorithm combines the idea of the first one and the best existing solution for homogeneous servers. Using document reallocation, we obtain a smooth tradeoff curve of the upper bounds of load and storage space. The last one bounds the load and storage space of each server by less than three times of their trivial lower bounds, respectively; and more importantly, for each server, the value of at least one parameter is far from its worst case. The time complexities of these three algorithms are O(\log M) plus the cost of document reallocation. © 2009 IEEE.