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Wyniki wyszukiwania dla: algorithm
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Improving depth maps of plants by using a set of five cameras
PublikacjaObtaining high-quality depth maps and disparity maps with the use of a stereo camera is a challenging task for some kinds of objects. The quality of these maps can be improved by taking advantage of a larger number of cameras. The research on the usage of a set of five cameras to obtain disparity maps is presented. The set consists of a central camera and four side cameras. An algorithm for making disparity maps called multiple...
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Compressive Sensing Approach to Harmonics Detection in the Ship Electrical Network
PublikacjaThe contribution of this paper is to show the opportunities for using the compressive sensing (CS) technique for detecting harmonics in a frequency sparse signal. The signal in a ship’s electrical network, polluted by harmonic distortions, can be modeled as a superposition of a small number of sinusoids and the discrete Fourier transform (DFT) basis forms its sparse domain. According to the theory of CS, a signal may be reconstructed...
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Sea surface temperature in the Baltic Sea derived from Landsat 8 satellite data - path 194
Dane BadawczeThe data set contains high resolution sea surface temperature (SST) maps estimated from Landsat 8 Level 1 Thermal Infrared Sensor (TIRS) data using NLSST algorithm. SST was calculated only for granules (185 x 180 km) from satellite path number 194, that covered at least 2000 km2 of the cloud-free area of the Baltic Sea.
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Sea surface temperature in the Baltic Sea derived from Landsat 8 satellite data - path 192
Dane BadawczeThe data set contains high resolution sea surface temperature (SST) maps estimated from Landsat 8 Level 1 Thermal Infrared Sensor (TIRS) data using NLSST algorithm. SST was calculated only for granules (185 x 180 km) from satellite path number 192, that covered at least 2000 km2 of the cloud-free area of the Baltic Sea.
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Sea surface temperature in the Baltic Sea derived from Landsat 8 satellite data - path 191
Dane BadawczeThe data set contains high resolution sea surface temperature (SST) maps estimated from Landsat 8 Level 1 Thermal Infrared Sensor (TIRS) data using NLSST algorithm. SST was calculated only for granules (185 x 180 km) from satellite path number 191, that covered at least 2000 km2 of the cloud-free area of the Baltic Sea.
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Sea surface temperature in the Baltic Sea derived from Landsat 8 satellite data - path 193
Dane BadawczeThe data set contains high resolution sea surface temperature (SST) maps estimated from Landsat 8 Level 1 Thermal Infrared Sensor (TIRS) data using NLSST algorithm. SST was calculated only for granules (185 x 180 km) from satellite path number 193, that covered at least 2000 km2 of the cloud-free area of the Baltic Sea.
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Sea surface temperature in the Baltic Sea derived from Landsat 8 satellite data - path 190
Dane BadawczeThe data set contains high resolution sea surface temperature (SST) maps estimated from Landsat 8 Level 1 Thermal Infrared Sensor (TIRS) data using NLSST algorithm. SST was calculated only for granules (185 x 180 km) from satellite path number 190, that covered at least 2000 km2 of the cloud-free area of the Baltic Sea.
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Estimation of object size in the calibrated camera image = Estymacja rozmiaru obiektów w obrazach ze skalibrowanej kamery
PublikacjaIn the paper, a method of estimation of the physical sizes of the objects tracked by the camera is presented. First, the camera is calibrated, then the proposed algorithm is used to estimate the real width and height of the tracked moving objects. The results of size estimation are then used for classification of the moving objects. Two methods of camera calibration are compared, test results are presented and discussed. The proposed...
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ESTIMATION OF NONSTATIONARY HARMONIC SIGNALS AND ITS APPLICATION TO ACTIVE CONTROL OF MRI NOISE
PublikacjaA new adaptive comb filtering algorithm, capable of tracking the fundamental frequency and amplitudes of different frequency components of a nonstationary harmonic signal embedded in white measurement noise, is proposed. Frequency tracking characteristics of the new scheme are studied analytically, proving (under Gaussian assumptions and optimal tuning) its statistical efficiency for quasi-linear frequency changes. Laboratory tests...
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Adaptive acoustic crosstalk cancellation in mobile computer device
PublikacjaThe cancellation of acoustic crosstalk is employed to enhance the stereo image in mobile listening conditions. A practical setup employing a mobile computer is employed. The adaptation of the crosstalk cancellation filter to the position of the listener's head is featured. The measurement evaluating the possibility of practical application of the method are described. The head and torso simulator was used for measurements. The...
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Mobile devices and computing cloud resources allocation for interactive applications
PublikacjaUsing mobile devices such as smartphones or iPads for various interactive applications is currently very common. In the case of complex applications, e.g. chess games, the capabilities of these devices are insufficient to run the application in real time. One of the solutions is to use cloud computing. However, there is an optimization problem of mobile device and cloud resources allocation. An iterative heuristic algorithm for...
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A Framework for Searching in Graphs in the Presence of Errors
PublikacjaWe consider a problem of searching for an unknown target vertex t in a (possibly edge-weighted) graph. Each vertex-query points to a vertex v and the response either admits that v is the target or provides any neighbor s of v that lies on a shortest path from v to t. This model has been introduced for trees by Onak and Parys [FOCS 2006] and for general graphs by Emamjomeh-Zadeh et al. [STOC 2016]. In the latter, the authors provide...
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Drum Replacement Using Wavelet Filtering Podmienianie próbek perkusyjnych przy zastosowaniu filtracji falkowej .
PublikacjaThe paper presents the solution that can be used to unify snare drum sound within a chosen fragment. The algorithm is based on the wavelet transformation and allows replacement of sub-bands of particular sounds, which are outside a certain range. Five experienced sound engineers put the algorithm under the test using samples of five different snare drums. Wavelet filtering seems to be useful in terms of drum replacement, while...
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On-line ranking of split graphs
PublikacjaA vertex ranking of a graph G is an assignment of positive integers (colors) to the vertices of G such that each path connecting two vertices of the same color contains a vertex of a higher color. Our main goal is to find a vertex ranking using as few colors as possible. Considering on-line algorithms for vertex ranking of split graphs, we prove that the worst case ratio of the number of colors used by any on-line ranking algorithm...
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On the Limiting Distribution of Lempel-Ziv’78 Redundancy for Memoryless Sources
PublikacjaWe study the Lempel-Ziv'78 algorithm and show that its (normalized) redundancy rate tends to a Gaussian distribution for memoryless sources. We accomplish it by extending findings from our 1995 paper, in particular, by presenting a new simplified proof of the central limit theorem (CLT) for the number of phrases in the LZ'78 algorithm. We first analyze the asymptotic behavior of the total path length in the associated digital search...
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Database of the estimations of the numbers of simplices of triangulation of some classical Lie groups
Dane BadawczeIt is know that any smooth manifold can be triangulated. The number of simplices of triangulation of a given manifold depends on its topological and combinatorial structure. The data consists of the lower bounds for the numbers of simplices of each dimension of any triangulation of classical Lie groups U(n), SU(n), Sp(n), and SO(n) for n up to 25. Each...
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Depth profile of the composition of 8 nm Al2O3 thin film
Dane Badawcze8 nm layer of aluminum oxide (Al2O3) was deposited by ALD method on a s. Atomic layer deposition provides precise thickness control down to a single atomic layer. The precursors used were trimethylaluminum (Sigma-Aldrich) and purified water. The deposition of the atomic layer was carried out at 200 °C. To investigate the profile of concenration of...
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Compensation of supply current harmonics, reactive power, and unbalanced load current balance in the closed-loop control of a shunt active power filter
PublikacjaThis paper presents the compensation tasks performed by a shunt active power filter, including compensation of harmonic currents, reactive power, and an unbalanced load current. The paper demonstrates novel control of the shunt active power filter in a closed-loop system. The control algorithm was verified by performing simulations and compared the simulated results with those obtained in an open-loop control system. All simulations...
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Locating and Identifying Ferromagnetic Objects
PublikacjaThe new non-iterative method of determining the dipole moment and location is presented in this paper. The algorithm of an object's localization and identification was achieved by using numerical calculations and approximation method. The arbitrary shapes of an object were assumed in the identification algorithm - axially symmetric spheroid (a prolate and an oblate). Several examples of localization and identification of an object's...
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A new approach to active noise and vibration control - [Part II: unknown frequency case]
PublikacjaThis paper presents a new approach to rejection of complex-valued sinusoidal disturbances acting at the output of a discrete-time stable linear plant with unknown and possibly timevarying dynamics. It is assumed that both the instantaneous frequency of the sinusoidal disturbance and its amplitude may be slowly varying with time and that the output signal is contaminated with wideband measurement noise. It is not assumed that a...
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Generalized adaptive comb filter with improved accuracy and robustness properties
PublikacjaGeneralized adaptive comb lters can be used to identify/track parameters of quasi-periodically varying systems.In a special, signal case they reduce down to adaptive comblters, applied to elimination or extraction of nonstationarymulti-harmonic signals buried in noise. We proposea new algorithm which combines, in an adaptive way, resultsyielded by several, simultaneously working generalizedadaptive comb lters. Due to its highly...
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Locating and Identifying Ferromagnetic Objects
PublikacjaThe new non-iterative method of determining the dipole moment and location is presented in this paper. The algorithm of an object's localization and identification was achieved by using numerical calculations and approximation method. The arbitrary shapes of an object were assumed in the identification algorithm - axially symmetric spheroid (a prolate and an oblate). Several examples of localization and identification of an object's...
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The Analysis of Patients' Airflow with Respect to Early Detection of Sleep Apnea
PublikacjaThe paper discusses the analysis of the respiratory events of sleep apnea patients. The analysis was carried out on the basis of the patient's airflow. As a result of the conducted analysis we proposed an algorithm which establishes an individual respiratory pattern for each subject. The algorithm could be implemented in the measurement - control system which manages the prosthetic device applying positive airway pressure. Its...
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Hybrid of Neural Networks and Hidden Markov Models as a modern approach to speech recognition systems
PublikacjaThe aim of this paper is to present a hybrid algorithm that combines the advantages ofartificial neural networks and hidden Markov models in speech recognition for control purpos-es. The scope of the paper includes review of currently used solutions, description and analysis of implementation of selected artificial neural network (NN) structures and hidden Markov mod-els (HMM). The main part of the paper consists of a description...
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Optimised Allocation of Hard Quality Sensors for Robust Monitoring of Quality in Drinking Water Distribution Systems
PublikacjaA problem of optimised placement of the hard quality sensors in Drinking Water Distribution Systems for robust quality monitoring is formulated. Two numerical algorithms to solve the problem are derived. The optimality is meant as achieving a desired trade off between the sensor capital and maintenance costs and resulting robust estimation accuracy of the monitoring algorithm. The robust estimation algorithm recently developed...
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Topology Discovery of Hierarchical Ethernet LANs without SNMP support
PublikacjaThis paper presents an algorithm that allows for discovery of layer-2 hierarchical Ethernet network topology using agents running on selected end nodes. No SNMP, MIB, hardware, firmware, or operating system-level software modification is required. The method is based on transmission of customized Ethernet frames among installed software agents. It can be used to discover the topology of LAN or one VLAN segment as long as no MAC...
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Sensorless Rotor Position Estimation of Doubly-Fed Induction Generator Based on Backstepping Technique
PublikacjaThis paper proposes a speed observer algorithm for the sensorless control of a doubly-fed induction generator based on classical adaptive backstepping technique. The sensorless control is shown using classic stator field oriented control which is used to active and reactive power control. Performance of the proposed algorithm of a speed observer is validated by simulation and experimental results obtained using a small-rating generator...
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High performance super-twisting sliding mode control for a maritime autonomous surface ship (MASS) using ADP-Based adaptive gains and time delay estimation
PublikacjaThis research addresses two kinds of problems related to optimal trajectory tracking of a Maritime Autonomous Surface Ship (MASS): those caused by the time-varying external disturbances including winds, waves and ocean currents as well as those resulting from inherent dynamical uncertainties. As the paper shows, an accurate and robust optimal controller can successfully deal with both issues. An improved Optimal Adaptive Super-Twisting...
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Further Developments of the Online Sound Restoration System for Digital Library Applications
PublikacjaNew signal processing algorithms were introduced to the online service for audio restoration available at the web address: www.youarchive.net. Missing or distorted audio samples are estimated using a specific implementation of the Jannsen interpolation method. The algorithm is based on the autoregressive model (AR) combined with the iterative complementation of signal samples. Since the interpolation algorithm is computationally...
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Reduced-cost electromagnetic-driven optimisation of antenna structures by means of trust-region gradient-search with sparse Jacobian updates
PublikacjaNumerical optimisation plays more and more important role in the antenna design. Because of lack of design-ready theoretical models, electromagnetic (EM)-simulation-driven adjustment of geometry parameters is a necessary step of the design process. At the same time, traditional parameter sweeping cannot handle complex topologies and large number of design variables. On the other hand, high computational cost of the conventional...
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High performance super-twisting sliding mode control for a maritime autonomous surface ship (MASS) using ADP-Based adaptive gains and time delay estimation
PublikacjaThis research addresses two kinds of problems related to optimal trajectory tracking of a Maritime Autonomous Surface Ship (MASS): those caused by the time-varying external disturbances including winds, waves and ocean currents as well as those resulting from inherent dynamical uncertainties. As the paper shows, an accurate and robust optimal controller can successfully deal with both issues. An improved Optimal Adaptive Super-Twisting...
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Predicting emotion from color present in images and video excerpts by machine learning
PublikacjaThis work aims at predicting emotion based on the colors present in images and video excerpts using a machine-learning approach. The purpose of this paper is threefold: (a) to develop a machine-learning algorithm that classifies emotions based on the color present in an image, (b) to select the best-performing algorithm from the first phase and apply it to film excerpt emotion analysis based on colors, (c) to design an online survey...
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Real-Time Gastrointestinal Tract Video Analysis on a Cluster Supercomputer
PublikacjaThe article presents a novel approach to medical video data analysis and recognition. Emphasis has been put on adapting existing algorithms detecting le- sions and bleedings for real time usage in a medical doctor's office during an en- doscopic examination. A system for diagnosis recommendation and disease detec- tion has been designed taking into account the limited mobility of the endoscope and the doctor's requirements. The...
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Optimal shape design of multi-element trawl-doors using local surrogate models
PublikacjaTrawl-doors have a large influence on the fuel consumption of fishing vessels. Design and optimiza-tion of trawl-doors using computational models are a key factor in minimizing the fuel consump-tion. This paper presents an optimization algorithm for the shape design of trawl-door shapes using computational fluid dynamic (CFD) models. Accurate CFD models are computationally expensive. Therefore, the direct use of traditional optimization...
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Improving Traffic Light Recognition Methods using Shifting Time-Windows
PublikacjaWe propose a novel method of improving algorithms recognizing traffic lights in video sequences. Our focus is on algorithms for applications which notify the driver of a light in sight. Many existing methods process images in the recording separately. Our method bases on the observation that real-life videos depict underlying continuous processes. We named our method FSA (Frame Sequence Analyzed). It is applicable for any underlying...
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Improving methods for detecting people in video recordings using shifting time-windows
PublikacjaWe propose a novel method for improving algorithms which detect the presence of people in video sequences. Our focus is on algorithms for applications which require reporting and analyzing all scenes with detected people in long recordings. Therefore one of the target qualities of the classification result is its stability, understood as a low number of invalid scene boundaries. Many existing methods process images in the recording...
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A bisection‐based heuristic for rapid EM‐driven multiobjective design of compact impedance transformers
PublikacjaDesign of microwave structures is a multiobjective task where several conflicting requirements have to be considered at the same time. For contemporary circuits characterized by complex geometries, multiobjective optimization cannot be performed using standard population‐based algorithms due to high cost of electromagnetic (EM) evaluations. In this work, we propose a deterministic approach for fast EM‐driven multiobjective design...
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Reduced-cost design closure of antennas by means of gradient search with restricted sensitivity update
PublikacjaDesign closure, i.e., adjustment of geometry parameters to boost the performance, is a challenging stage of antenna design process. Given complexity of contemporary structures, reliable parameter tuning requires numerical optimization and can be executed using local algorithms. Yet, EM-driven optimization is a computationally expensive endeavour and reducing its cost is highly desirable. In this paper, a modification of the trust-region...
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Design of a Multidomain IMS/NGN Service Stratum
PublikacjaThe paper continues our research concerning the Next Generation Network (NGN), which is standardized for delivering multimedia services with strict quality and includes elements of the IP Multimedia Subsystem (IMS). A design algorithm for a multidomain IMS/NGN service stratum is proposed, which calculates the necessary CSCF servers CPU message processing times and link bandwidths with respect to the given maximum values of mean...
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Ship Dynamic Positioning Based on Nonlinear Model Predictive Control
PublikacjaThe presented work explores the simulation test results of using nonlinear model predictive control algorithm for ship dynamic positioning. In the optimization task, a goal function with a penalty was proposed with a variable prediction step. The results of the proposed control algorithm were compared with backstepping and PID. The effect of estimation accuracy on the control quality with the implemented algorithms was investigated....
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Trees having many minimal dominating sets
PublikacjaWe provide an algorithm for listing all minimal dominating sets of a tree of order n in time O(1.4656^n). This leads to that every tree has at most 1.4656^n minimal dominating sets. We also give an infinite family of trees of odd and even order for which the number of minimal dominating sets exceeds 1.4167^n, thus exceeding 2^{n/2}. This establishes a lower bound on the running time of an algorithm for listing all minimal dominating...
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METHOD OF ROUTING SHIPS SAILING IN DEDICATED ENVIRONMENT
PublikacjaThe method for determining the suboptimal route of sailing vessels operating in a restricted area of the sea are proposed in the paper. The dynamics of the environment including weather conditions and speed characteristics of ships sailing are considered. As optimiza-tion criterion, measure sailing time T, and the number of maneuvers performed ω, are taken into account. An heuristic algorithm, and the appropriate application routing...
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Generalized adaptive notch filters with frequency debiasing for tracking of polynomial phase systems
PublikacjaGeneralized adaptive notch filters are used for identification/tracking of quasi-periodically varying dynamic systems and can be considered an extension, to the system case, of classical adaptive notch filters. For general patterns of frequency variation the generalized adaptive notch filtering algorithms yield biased frequency estimates. We show that when system frequencies change slowly in a smooth way, the estimation bias can...
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Wideband Model Order Reduction for Macromodels in Finite Element Method
PublikacjaAbstract: This paper presents a novel algorithm for accelerating 3D Finite Element Method simulations by introducing macromodels created in local model order reduction in the selected subdomains of the computational domain. It generates the projection basis for a compact system of equations associated with a separate subdomain. Due to non-linear frequency dependency in the Right Hand Side (RHS), the standard reduction methods do...
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A quaternion-based modified feistel cipher for multimedia transmission
PublikacjaIn this paper a quaternion-based modified Feistel Cipher is proposed. The algorithm is based on the scheme proposed by Sastry and Kumar (2012). Our algorithm uses special properties of quaternions to perform rotations of data sequences in 3D space for each of the cipher rounds. The plaintext (image in gray-tone) is divided into two square matrices of equal size which consist of Lipschitz quaternions. A modular arithmetic was implemented...
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Multi-objective Tabu-based Differential Evolution for Teleportation of Smart Virtual Machines in Private Computing Clouds
PublikacjaWe propose a multi-objective approach for using differential evolution algorithm with tabu search algorithm as an additional mutation for live migration (teleportation) of virtual machines. This issue is crucial in private computing clouds. Teleportation of virtual machines is supposed to be planned to determine Pareto-optimal solutions for several criteria such as workload of the bottleneck host, communication capacity of the...
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Designing of Track Axis Alignment with the Use of Satellite Measurements and Particle Swarm Optimization
PublikacjaDesigning of the track’s alignment is a key issue from the point of view of maintaining of proper geometries. The paper presents a design method for sections of railway line located in the horizontal arch. The method is adapted to the technique of mobile satellite measurements. The general principles of this measurement method have been described in the article. A project's solution has been presented using mathematical notation...
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Dynamic coloring of graphs
PublikacjaDynamics is an inherent feature of many real life systems so it is natural to define and investigate the properties of models that reflect their dynamic nature. Dynamic graph colorings can be naturally applied in system modeling, e.g. for scheduling threads of parallel programs, time sharing in wireless networks, session scheduling in high-speed LAN's, channel assignment in WDM optical networks as well as traffic scheduling. In...
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Distributed graph searching with a sense of direction
PublikacjaIn this work we consider the edge searching problem for vertex-weighted graphs with arbitrarily fast and invisible fugitive. The weight function w provides for each vertex v the minimum number of searchers required to guard v, i.e., the fugitive may not pass through v without being detected only if at least w(v) searchers are present at v. This problem is a generalization of the classical edge searching problem, in which one has...
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On-line Search in Two-Dimensional Environment
PublikacjaWe consider the following on-line pursuit-evasion problem. A team of mobile agents called searchers starts at an arbitrary node of an unknown network. Their goal is to execute a search strategy that guarantees capturing a fast and invisible intruder regardless of its movements using as few searchers as possible. We require that the strategy is connected and monotone, that is, at each point of the execution the part of the graph...