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Tytuł:
RED-LE: A Revised Algorithm for Active Queue Management
Autorzy:
Hassan, Samuel O.
Powiązania:
https://bibliotekanauki.pl/articles/2142301.pdf
Data publikacji:
2022
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
active queue management
network congestion
router
RED-LE
simulation
Opis:
The random early detection (RED) algorithm was developed in 1993. Nearly three decades later, several improved variants have been proposed by scientists. The use of a (pure) linear function for computing packet drop probability has turned out to be a disadvantage, leading to the problem of large delays. Such a problem may be addressed by using linear and non-linear (i.e. as exponential) packet drop probability functions. This paper proposes a revised RED active queue management algorithm named RED-linear exponential (RED-LE). This variant involves an interplay of linear and exponential drop functions, in order to improve the performance of the original RED algorithm. More importantly, at low and moderate network traffic loads, the RED-LE algorithm employs the linear drop action. However, for high traffic loads, RED-LE employs the exponential function for computing the packet drop probability rate. Experimental results have shown that RED-LE effectively controls congestion and offers an improved network performance under different traffic loads.
Źródło:
Journal of Telecommunications and Information Technology; 2022, 2; 91--97
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new algorithm for calculating the most reliable pair of disjoint paths in a network
Autorzy:
Gomes, T.
Craveirinha, J.
Violante, A.
Powiązania:
https://bibliotekanauki.pl/articles/308916.pdf
Data publikacji:
2006
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
reliability
OR in telecommunications
routing
Opis:
In various types telecommunication networks, namely mobile ad hoc networks, WDM networks and MPLS networks, there is the necessity of calculating disjoint paths for given node to node connections in order to increase the reliability of the services supported by these networks. This leads to the problem of calculating a pair of disjoint paths (or a set of disjoint paths) which optimises some measure of performance in those networks. In this paper we present an algorithm, designated as OptDP, for obtaining the most reliable pair of disjoint paths based on the loopless version of MPS, a very efficient k-shortest path algorithm, and on Dijkstra algorithm. Since to the best of our knowledge there is no other proposal of an algorithm capable of solving exactly the same problem we perform a comparison with the application to this problem of the DPSP algorithm which calculates a set of disjoint paths with high reliability. Also a comparison with a simplified version (designated as NopDP) of the proposed algorithm, which stops after a maximal number F of candidate pairs of paths have been found, is presented. The comparison also includes the percentage of cases in which both algorithms were not capable of finding the optimal pair.
Źródło:
Journal of Telecommunications and Information Technology; 2006, 4; 31-38
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Call-level Analysis of a Two-Link Multirate Loss Model based on a Convolution Algorithm
Autorzy:
Sagkriotis, S. G.
Pantelis, S. K.
Moscholios, I. D.
Vassilakis, V. G.
Powiązania:
https://bibliotekanauki.pl/articles/309118.pdf
Data publikacji:
2018
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
call blocking
convolution
loss model
offoading
product form
Opis:
We consider a two-link system that accommodates Poisson arriving calls from different service-classes and propose a multirate teletraffic loss model for its analysis. Each link has two thresholds, which refer to the number of in-service calls in the link. The lowest threshold, named support threshold, defines up to which point the link can support calls offloaded from the other link. The highest threshold, named offloading threshold, defines the point where the link starts offloading calls to the other link. The adopted bandwidth sharing policy is the complete sharing policy, in which a call can be accepted in a link if there exist enough available bandwidth units. The model does not have a product form solution for the steady state probabilities. However, we propose approximate formulas, based on a convolution algorithm, for the calculation of call blocking probabilities. The accuracy of the formulas is verified through simulation and found to be quite satisfactory.
Źródło:
Journal of Telecommunications and Information Technology; 2018, 1; 3-10
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Novel Kernel Algorithm for Finite Impulse Response Channel Identification
Autorzy:
Fateh, Rachid
Darif, Anouar
Boumezzough, Ahmed
Safi, Said
Frikel, Miloud
Powiązania:
https://bibliotekanauki.pl/articles/24200741.pdf
Data publikacji:
2023
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
finite impulse response
kernel adaptive filtering
kernel recursive projection identification
nonlinear system identification
Opis:
Over the last few years, kernel adaptive filters have gained in importance as the kernel trick started to be used in classic linear adaptive filters in order to address various regression and time-series prediction issues in nonlinear environments.In this paper, we study a recursive method for identifying finite impulse response (FIR) nonlinear systems based on binary-value observation systems. We also apply the kernel trick to the recursive projection (RP) algorithm, yielding a novel recursive algorithm based on a positive definite kernel. For purposes, our approach is compared with the recursive projection (RP) algorithm in the process of identifying the parameters of two channels, with the first of them being a frequency-selective fading channel, called a broadband radio access network (BRAN B) channel, and the other being a a theoretical frequency-selective channel, known as the Macchi channel. Monte Carlo simulation results are presented to show the performance of the proposed algorithm.
Źródło:
Journal of Telecommunications and Information Technology; 2023, 2; 84--93
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design of a Modified Interleaving Algorithm Based on Golden Section Theory Enhancing the Performance of Turbo Codes
Autorzy:
Iftene, Essedik
Ali-Pacha, Adda
Abderrahmane, Lahcene Hadj
Powiązania:
https://bibliotekanauki.pl/articles/2142311.pdf
Data publikacji:
2022
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
AWGN channel
golden section theory
interleaver
iterative decoding
Rayleigh fading channel
turbo codes
Opis:
This paper investigates the design of a modified matrix interleaving algorithm as a way to improve the performance of turbo codes. This proposed solution, known as the matrix-dithered golden (MDG) interleaver, utilizes the characteristics of a matrix interleaver combined with the golden section theory. The performance of the proposed interleaving method is compared with that of matrix (M), random (R), and dithered golden (DG) interleavers. The comparison is made in terms of bit error rate (BER), frame error rate (FER), computational complexity, and storage memory requirement. The turbo coded system is implemented and simulated using Matlab/Simulink software. Results of simulations performed both in the additive white Gaussian noise (AWGN) channel and the Rayleigh fading channel demonstrate the effectiveness of the proposed interleaver. The MDG interleaver is an effective replacement for random interleavers, as it improves BER and FER performance of the turbo code and is also capable of reducing the storage memory requirement without increasing the system’s complexity.
Źródło:
Journal of Telecommunications and Information Technology; 2022, 2; 35--42
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
FDTD modeling and experimental verification of electromagnetic power dissipated in domestic microwave ovens
Autorzy:
Kopyt, P.
Celuch-Marcysiak, M.
Powiązania:
https://bibliotekanauki.pl/articles/309259.pdf
Data publikacji:
2003
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
symulacja elektromagnetyczna
algorytm FDTD
nagrzewanie mikrofalowe
electromagnetic simulations
FDTD algorithm
microwave heating
Opis:
The FDTD (Finite Difference Time Domain) method has proven to be effective in modeling high-frequency electromagnetic problems in telecommunications industry. Recently it has been successfully applied in microwave power engineering. In order to accurately model scenarios typical in this field one has to deal with the movement of objects placed inside cavities. This paper describes a simple algorithm that makes it possible to take into account object rotation - important in simulations of domestic microwave ovens. Results of example simulations are presented and an experimental verification of the simulation tool is performed.
Źródło:
Journal of Telecommunications and Information Technology; 2003, 1; 59-65
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Computational Methods for Two-Level 0-1 Programming Problems through Distributed Genetic Algorithms
Autorzy:
Niwa, K.
Hayashida, T.
Sakawa, M.
Powiązania:
https://bibliotekanauki.pl/articles/309162.pdf
Data publikacji:
2010
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
distributed genetic algorithm
Stackelberg solution
two-level 0-1 programming problem
Opis:
In this paper, we consider a two-level 0-1 programming problem in which there is not coordination between the decision maker (DM) at the upper level and the decision maker at the lower level. We propose a revised computational method that solves problems related to computational methods for obtaining the Stackelberg solution. Specifically, in order to improve the computational accuracy of approximate Stakelberg solutions and shorten the computational time of a computational method implementing a genetic algorithm (GA) proposed by the authors, a distributed genetic algorithm is introduced with respect to the upper level GA, which handles decision variables for the upper level DM. Parallelization of the lower level GA is also performed along with parallelization of the upper level GA. The proposed algorithm is also improved in order to eliminate unnecessary computation during operation of the lower level GA, which handles decision variables for the lower level DM. In order to verify the effectiveness of the proposed method, we propose comparisons with existing methods by performing numerical experiments to verify both the accuracy of the solution and the time required for the computation.
Źródło:
Journal of Telecommunications and Information Technology; 2010, 2; 78-87
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Data Fixing Algorithm in Radiosonde Monitoring Process
Autorzy:
Szuster, P.
Powiązania:
https://bibliotekanauki.pl/articles/308014.pdf
Data publikacji:
2017
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
aerology
data fixing
data fusion
meteorological data
monitoring
radiosondes
Opis:
Earth surface monitoring can give information that may be used in complex analysis of the air conditions, temperature, humidity etc. Data from a vertical profile of the atmosphere is also essential for accurate thunderstorm forecasting. That data is collected by radiosondes – telemetry instruments carried into the atmosphere usually by balloons. Sometimes, due to the hostile conditions of upper troposphere, incorrect data can be generated by radiosonde sensors. In this paper, a new algorithm is developed for fixing the incorrect data, i.e. missing or out of specific range values. The proposed algorithm was tested both on benchmarks and real data generated by radiosondes. About 70% of significantly damaged test data volume was recovered. Up to 100% of real data was fixed.
Źródło:
Journal of Telecommunications and Information Technology; 2017, 1; 81-88
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Support Vector Machine based Decoding Algorithm for BCH Codes
Autorzy:
Sudharsan, V.
Yamuna, B.
Powiązania:
https://bibliotekanauki.pl/articles/958048.pdf
Data publikacji:
2016
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
BCH codes
Chase-2 algorithm
coding gain
kernel
multi-class classification
Soft Decision Decoding
Support Vector Machine
Opis:
Modern communication systems require robust, adaptable and high performance decoders for efficient data transmission. Support Vector Machine (SVM) is a margin based classification and regression technique. In this paper, decoding of Bose Chaudhuri Hocquenghem codes has been approached as a multi-class classification problem using SVM. In conventional decoding algorithms, the procedure for decoding is usually fixed irrespective of the SNR environment in which the transmission takes place, but SVM being a machinelearning algorithm is adaptable to the communication environment. Since the construction of SVM decoder model uses the training data set, application specific decoders can be designed by choosing the training size efficiently. With the soft margin width in SVM being controlled by an equation, which has been formulated as a quadratic programming problem, there are no local minima issues in SVM and is robust to outliers.
Źródło:
Journal of Telecommunications and Information Technology; 2016, 2; 108-112
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evolutionary Algorithm that Designs the DNA Synthesis Procedure
Autorzy:
Michalak, M.
Nowak, R.
Powiązania:
https://bibliotekanauki.pl/articles/308431.pdf
Data publikacji:
2011
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
bioinformatics
gene synthesis
optimum searching
Opis:
Chemical synthesis of nucleotide chains is very erroneous for long sequences. Often a gene is constructed from short fragments joined with the use of complementary helper chains. The number of possible potential solutions for a long gene synthesis is very large, therefore a fast automated search is required. In the presented approach a modified method of long DNA construction is proposed. A computer program that searches for an optimal solution in the space of potential synthesis methods has been developed. This software uses an evolutionary algorithm for global optimization and a hillclimbing algorithm for local optimization. The long DNA construction method was tested on random sequences. The results are very promising. The next step is to perform experiments in a biotechnological wet laboratory involving DNA strand synthesis using the method designed by the presented software.
Źródło:
Journal of Telecommunications and Information Technology; 2011, 4; 50-54
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fault Tolerant Dense Wavelength Division Multiplexing Optical Transport Networks
Autorzy:
Ren, W.
Naderi, M.
Leeson, M.
Hines, E.
Powiązania:
https://bibliotekanauki.pl/articles/308964.pdf
Data publikacji:
2009
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
dedicated path protection architecture
genetic algorithm
DWDM
fault-tolerant networks
optical networks
Opis:
Design of fault tolerant dense wavelength division multiplexing (DWDM) backbones is a major issue for service provision in the presence of failures. The problem is an NP-hard problem. This paper presents a genetic algorithm based approach for designing fault tolerant DWDM optical networks in the presence of a single link failure. The working and spare lightpaths are encoded into variable length chromosomes. Then the best lightpaths are found by use of a fitness function and these are assigned the minimum number of wavelengths according to the problem constraints using first-fit (FF) algorithm. The proposed approach has been evaluated for dedicated path protection architecture. The results, obtained from the ARPA2 test bench network, show that the method is well suited to tackling this complex and multi-constraint problem.
Źródło:
Journal of Telecommunications and Information Technology; 2009, 1; 63-67
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Monte Carlo Tree Search Algorithm for the Euclidean Steiner Tree Problem
Autorzy:
Bereta, M.
Powiązania:
https://bibliotekanauki.pl/articles/308683.pdf
Data publikacji:
2017
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
Euclidean Steiner tree problem
MCTS
Monte Carlo Tree Search
UCT algorithm
Opis:
This study is concerned with a novel Monte Carlo Tree Search algorithm for the problem of minimal Euclidean Steiner tree on a plane. Given p p p points (terminals) on a plane, the goal is to find a connection between all the points, so that the total sum of the lengths of edges is as low as possible, while an addition of extra points (Steiner points) is allowed. Finding the minimum Steiner tree is known to be np-hard. While exact algorithms exist for this problem in 2D, their efficiency decreases when the number of terminals grows. A novel algorithm based on Upper Confidence Bound for Trees is proposed. It is adapted to the specific characteristics of Steiner trees. A simple heuristic for fast generation of feasible solutions based on Fermat points is proposed together with a correction procedure. By combing Monte Carlo Tree Search and the proposed heuristics, the proposed algorithm is shown to work better than both the greedy heuristic and pure Monte Carlo simulations. Results of numerical experiments for randomly generated and benchmark library problems (from OR-Lib) are presented and discussed.
Źródło:
Journal of Telecommunications and Information Technology; 2017, 4; 71-81
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Problem of Detecting Stops While Tracking Moving Objects Under the Stream Processing Regime
Autorzy:
Białoń, Paweł M.
Powiązania:
https://bibliotekanauki.pl/articles/27312949.pdf
Data publikacji:
2023
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
algorithm complexity
GPS monitoring
object tracking
physical activity monitoring
stream processing
Opis:
The tracking of moving objects with the use of GPS/GNSS or other techniques is relied upon in numerous applications, from health monitoring and physical activity support, to social investigations to detection of fraud in transportation. While monitoring movement, a common subtask consists in determining the object’s moving periods, and its immobility periods. In this paper, we isolate the mathematical problem of automatic detection of a stop of tracking objects under the stream processing regime (ideal data processing algorithm regime) in which one is allowed to use only a constant amount of memory, while the stream of GNSS positions of the tracked object increases in size. We propose an approximation scheme of the stop detection problem based on the fuzziness in the approximation of noise level related to the position reported by GNSS. We provide a solving algorithm that determines some upper bounds for the problem’s complexity. We also provide an experimental illustration of the problem at hand.
Źródło:
Journal of Telecommunications and Information Technology; 2023, 4; 123-132
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Genetic Algorithm for Combined Speaker and Speech Recognition using Deep Neural Networks
Autorzy:
Kaur, G.
Srivastava, M.
Kumar, A.
Powiązania:
https://bibliotekanauki.pl/articles/958089.pdf
Data publikacji:
2018
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
deep neural networks
genetic algorithm
LPCC
MFCC
PLP
RASTA-PLP
speaker recognition
speech recognition
Opis:
Huge growth is observed in the speech and speaker recognition field due to many artificial intelligence algorithms being applied. Speech is used to convey messages via the language being spoken, emotions, gender and speaker identity. Many real applications in healthcare are based upon speech and speaker recognition, e.g. a voice-controlled wheelchair helps control the chair. In this paper, we use a genetic algorithm (GA) for combined speaker and speech recognition, relying on optimized Mel Frequency Cepstral Coefficient (MFCC) speech features, and classification is performed using a Deep Neural Network (DNN). In the first phase, feature extraction using MFCC is executed. Then, feature optimization is performed using GA. In the second phase training is conducted using DNN. Evaluation and validation of the proposed work model is done by setting a real environment, and efficiency is calculated on the basis of such parameters as accuracy, precision rate, recall rate, sensitivity, and specificity. Also, this paper presents an evaluation of such feature extraction methods as linear predictive coding coefficient (LPCC), perceptual linear prediction (PLP), mel frequency cepstral coefficients (MFCC) and relative spectra filtering (RASTA), with all of them used for combined speaker and speech recognition systems. A comparison of different methods based on existing techniques for both clean and noisy environments is made as well.
Źródło:
Journal of Telecommunications and Information Technology; 2018, 2; 23-31
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimized Energy Aware Resource Allocation Algorithm Using Software Defined Network Technology
Autorzy:
Al-Musawi, Ranya
Al-Khatib, Obada
Powiązania:
https://bibliotekanauki.pl/articles/309122.pdf
Data publikacji:
2019
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
computer network management
network servers
software defined networking
virtual machines
Opis:
The number of data centers (DCs) used for storing and processing data has evolved rapidly in recent years. However, the operations held by DCs may relate to a number of disadvantages, primarily presuming in excessive energy and power consumption due to the poor management standards applied. This may lead to a situation in which many devices within the DC operate at full capacity without any tasks assigned for actual execution. A Software Defined Network (SDN) is a network architecture where the control plane is an independent entity from the data plane, yielding to a higher controllability and flexibility over the network. Through the utilization of SDN architecture, a highly functional energy aware network may be established. In this paper, we propose a heuristic algorithm that monitors the current status of an SDN network (in addition to all ingoing and outgoing traffic), in order to dynamically and efficiently allocate network resources by ensuring that only the necessary network devices are active and by turning the idle ones off. The results show that the proposed algorithm reduces energy consumption of the network compared to existing solutions.
Źródło:
Journal of Telecommunications and Information Technology; 2019, 2; 83-91
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł

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