Search results for "algorithm."
showing 10 items of 4617 documents
On the use of generalized harmonic means in image processing using multiresolution algorithms
2019
In this paper we design a family of cell-average nonlinear prediction operators that make use of the generalized harmonic means and we apply the resulting schemes to image processing. The new famil...
Parallel distance transforms on pyramid machines: Theory and implementation
1990
Abstract A distance transform of a binary image is an array each of whose elements gives the distance from the corresponding pixel to the closest ‘1’ in the binary image. Distance transforms have uses in image matching and shape analysis, among other applications. We present a parallel algorithm for weighted distance transforms that runs particularly efficiently on hierarchical cellular-logic machines, a subclass of the architectures known as pyramid machines. The algorithm computes the 3–4 distance transform; however it can be readily adapted to the city-block (‘Manhattan’) and chessboard distance measures. The algorithm runs in O(M) time, for an M × M image. Since it avoids using arithmet…
Simultaneous Color Contrast in Goldfish— a Quantitative Study
1997
AbstractA set of 9–15 colored test fields was presented to goldfish. In Experiment 1, test field hues ranged from green through yellow to red; in Experiment 2, the hues varied from blue through gray to yellow. In the training conditions, the test fields were presented with a gray or black surround. The fish learned to choose one intermediate test field hue by rewarding them with food. In the test conditions, the color of the surround was changed from gray to green, or red (Experiment 1), and from black to blue, or yellow (Experiment 2). The choice behavior of the goldfish changed substantially: one of the test fields other than the training test field was preferred. Direction and strength o…
Lau Effect And Binary Logic
1989
The Lau effect is applied to implement the whole set of binary logic operations optically. Our technique works with spatially incoherent light and does not require lenses or any other optical accessory.
Optimization of the Relay Selection Scheme in Cooperative Retransmission Networks
2011
Cooperative MAC protocol design has attracted much attention recently thanks to the development of relaying techniques. In single-relay C-ARQ, the relay selection scheme cannot work efficiently in a dense network, due to high collision probability among different contending relays. In this paper, the throughput performance impairment from the collision is analysed in a typical network scenario. Thereby, we propose an optimized relay selection scheme aiming at maximizing system throughput by reducing collision probability. The throughput performance enhancement by the proposed optimal relay selection scheme is verified by simulations.
On the performance of hybrid-ARQ with code combining over double rayleigh fading channels
2011
In this paper, we study the performance of hybrid automatic repeat request (HARQ) with code combining (CC) over double Rayleigh channels. This channel can be utilized to model the fading envelope of vehicle-to-vehicle (V2V) channels. We derive analytical solutions for the characteristic quantities of double Rayleigh channels, such as the outage probability, the ergodic capacity, and the bit error probability (BEP). Moreover, we study the performance of HARQ with CC. Our analysis focuses on information theoretic aspects of HARQ with CC. closed-form analytical approximations are derived for the e-outage capacity, the average number of transmissions, and the average transmission rate of HARQ w…
Optimization of a Time-to-Digital Converter and a coincidence map algorithm for TOF-PET applications
2015
This contribution describes the optimization of a multichannel high resolution Time-to-Digital Converter (TDC) in a Field-Programmable Gate Array (FPGA) initially capable of obtaining time resolutions below 100ps for multiple channels. Due to its fast propagation capability it has taken advantage of the FPGA internal carry logic for accurate time measurements. Furthermore, the implementation of the TDC has been performed in different clock regions and tested with different frequencies as well, achieving improvements of up to 50% for a pair of channels. Moreover, since the TDC is potentially going to be used in a trigger system for Positron Emission Tomography (PET), the algorithm for coinci…
Experimental evaluation of topological-based fitness functions to detect complexes in PPI networks
2012
The detection of groups of proteins sharing common biological features is an important research issue, intensively investigated in the last few years, because of the insights it can give in understanding cell behavior. In this paper we present an extensive experimental evaluation campaign aiming at exploring the capability of Genetic Algorithms (GAs) to find clusters in protein-protein interaction networks, when different topological-based fitness functions are employed. A complete experimentation on the yeast protein-protein interaction network, along with a comparative evaluation of the effectiveness in detecting true complexes on the yeast and human networks, reveals GAs as a feasible an…
Breedbot: An Edutainment Robotics System to Link Digital and Real World
2007
The paper describes Breedbot an edutainment software and hardware system that could be used to evolve autonomous agents in digital (software) world and to transfer the evolved minds in physical agents (robots). The system is based on a wide variety of Artificial Life techniques (Artificial Neural Networks, Genetic Algorithms, User Guided Evolutionary Design and Evolutionary Robotics). An user without any computer programming skill can determine the robot behaviour. Breedbot was used as a didactic tool in teaching Evolutionary Biology and as a futuristic toy by several Science Centers. The digital side of Breedbot is downloadable from www.isl.unina.it/breedbot.
Evolutionary approach to coverage testing of IEC 61499 function block applications
2015
The paper addresses the problem of coverage testing of industrial automation software represented in the IEC 61499 standard, one of the recent standards for distributed control system design. Contrary to model-based testing (MBT), the paper focuses on implementation coverage, not model coverage. An approach based on evolutionary algorithms is presented which generates coverage test suites for both basic and composite IEC 61499 function blocks. It employs two third-party tools, FBDK and EvoSuite. The evaluation of the approach was performed on a set of control applications for two lab-scale demonstration plants. Results show that the approach is applicable and shows good performance at least…