An accelerated and robust algorithm for ant colony optimization in continuous functions

There is a wide variety of computational methods used for solving optimization problems. Among these, there are various strategies that are derived from the concept of ant colony optimization (ACO). However, the great majority of these methods are limited-range-search algorithms, that is, they find the optimal solution, as long as the domain provided contains this solution. This becomes a limitation, due to the fact that it does not allow these algorithms to be applied successfully to real-world problems, as in the real world, it is not always possible to determine with certainty the correct domain. The article proposes the use of a broad-range search algorithm, that is, that seeks the optimal solution, with success most of the time, even if the initial domain provided does not contain this solution, as the initial domain provided will be adjusted until it finds a domain that contains the solution. This algorithm called ARACO, derived from RACO, makes for the obtaining of better results possible, through strategies that accelerate the parameters responsible for adjusting the supplied domain at opportune moments and, in case there is a stagnation of the algorithm, expansion of the domain around the best solution found to prevent the algorithm becoming trapped in a local minimum. Through these strategies, ARACO obtains better results than its predecessors, in relation to the number of function evaluations necessary to find the optimal solution, in addition to its 100% success rate in practically all the tested functions, thus demonstrating itself as being a high performance and reliable algorithm. The algorithm has been tested on some classic benchmark functions and also on the benchmark functions of the IEEE Congress of Evolutionary Computation Benchmark Test Functions (CEC 2019 100-Digit Challenge).

Orthogonal Range Search Data Structures

We first review existing space-efficient data structures for the orthogonal range search problem. Then, we propose two improved data structures, the first of which has better query time complexity than the existing structures and the second of which has better space complexity that matches the information-theoretic lower bound.

AN EXPERIMENTAL ANALYSIS OF SPATIAL INDEXING ALGORITHMS FOR REAL TIME SAFETY CRITICAL MAP APPLICATION

This paper presents a study that compares the three space partitioning and spatial indexing techniques, KD Tree, Quad KD Tree, and PR Tree. KD Tree is a data structure proposed by Bentley (Bentley and Friedman, 1979) that aims to cluster objects according to their spatial location. Quad KD Tree is a data structure proposed by Berezcky (Bereczky et al., 2014) that aims to partition objects using heuristic methods. Unlike Bereczky’s partitioning technique, a new partitioning technique is presented based on dividing objects according to space-driven, in the context of this study. PR Tree is a data structure proposed by Arge (Arge et al., 2008) that is an asymptotically optimal R-Tree variant, enables data-driven segmentation. This study mainly aimed to search and render big spatial data in real-time safety-critical avionics navigation map application. Such a real-time system needs to efficiently reach the required records inside a specific boundary. Performing range query during the runtime (such as finding the closest neighbors) is extremely important in performance. The most crucial purpose of these data structures is to reduce the number of comparisons to solve the range searching problem. With this study, the algorithms’ data structures are created and indexed, and worst-case analyses are made to cover the whole area to measure the range search performance. Also, these techniques’ performance is benchmarked according to elapsed time and memory usage. As a result of these experimental studies, Quad KD Tree outperformed in range search analysis over the other techniques, especially when the data set is massive and consists of different geometry types.

Поведение ленского осетра Acipenser baerii, Brandt при использовании нового типа корма

Ставилась задача исследовать влияние типа корма на пищевое поведение молоди ленского осетра, оценить поведение особей в фазе ближнего поиска и обнаружения пищевого объекта. Исследования проводили методом периодов на одной группе рыб, 5 экземпляров. Было установлено, что пищевой поиск нового типа корма исследуемые особи прошли успешно: пищевой объект удерживался рыбой после первого схватывания. К концу опытов при кормлении рыбы гидролизатом продолжительность латентного времени питания снижалась, что свидетельствует о процессах привыкания к новому типу корма. При кормлении гидролизатом за три дня эксперимента латентное время питания сократилось на 13 пунктов. При кормлении же комбикормом продолжительность латентного времени питания, наоборот, увеличилась в 2,2 раза. Время, проведённое на кормовом пятне молодью ленского осетра контрольной и опытной групп, также было различным. Частички комбикорма рыбы съедали быстрее, чем гидролизат. В целом по эксперименту наибольшее влияние фактор тип корма оказывает на скорость питания (5,86). Рацион питания практически не зависит от типа корма.The task was to investigate the influence of the type of feed on the feeding behavior of juvenile Lena sturgeon, to evaluate the behavior of individuals in the phase of short-range search and detection of a prey. The researches were conducted by the method of periods on one group of fish with 5 specimens. It was found that the food search for a new type of food was successful in individuals under investigation: the food object was held by fish after the first grasping. By the end of the experiments when feeding a fish with a condensed fish solubles the duration of latency feeding time has decreased which indicates the processes of getting used to the new type of food. When fed with a condensed fish solubles for three days of the experiment the latency feeding time was reduced by 13 points. When feeding with complete feed the duration of latent feeding time on the contrary has increased in 2.2 times. The time spent on the fodder spot by the juvenile Lena sturgeon of the control and experimental groups was also different. Particles of fish feed were eaten faster than the condensed fish solubles. On the whole of the experiment the feed type factor has the greatest influence on the feed rate (5.86). The diet is almost independent of the type of feed.