Search results for "ALGORITHM"
showing 10 items of 4887 documents
The mixed capacitated general routing problem with turn penalties
2011
In this paper we deal with the mixed capacitated general routing problem with turn penalties. This problem generalizes many important arc and node routing problems, and it takes into account turn penalties and forbidden turns, which are crucial in many real-life applications, such as mail delivery, waste collection and street maintenance operations. Through a polynomial transformation of the considered problem into a Generalized Vehicle routing problem, we suggest a new approach for solving this new problem by transforming it into an Asymmetric Capacitated Vehicle routing problem. In this way, we can solve the new problem both optimally and heuristically using existing algorithms. A powerfu…
A Simulation Analysis of the Microstructure of an Order Driven Financial Market with Multiple Securities and Portfolio Choices
2005
In this paper we propose an artificial market where multiple risky assets are exchanged. Agents are constrained by the availability of resources and trade to adjust their portfolio according to an exogenously given target portfolio. We model the trading mechanism as a continuous auction order-driven market. Agents are heterogeneous in terms of desired target portfolio allocations, but they are homogeneous in terms of trading strategies. We investigate the role played by the trading mechanism in affecting the dynamics of prices, trading volume and volatility. We show that the institutional setting of a double auction market is sufficient to generate a non-normal distribution of price changes…
Selection and micropropagation of valuable caper genotypes
2020
The high quality of the various biotypes present in the natural or cultivated state is one of the main features for caper production. Up to now, however, no selection activity has been carried out in order to identify the most suitable accessions for providing better quality products. In this paper, we report the first results of a selection of caper genotypes characterised by significant qualitative traits. A micropropagation protocol was evaluated in order to improve and allow the multiplication of the most promising Capparis spinosa L. subsp. spinosa genotypes, selected in Salina (Aeolian Islands), Sicily (Italy), in collaboration with the most important local growers.
Inverse estimation of terminal connections in the cardiac conduction system
2017
Modeling the cardiac conduction system is a challenging problem in the context of computational cardiac electrophysiology. Its ventricular section, the Purkinje system, is responsible for triggering tissue electrical activation at discrete terminal locations, which subsequently spreads throughout the ventricles. In this paper, we present an algorithm that is capable of estimating the location of the Purkinje system triggering points from a set of random measurements on tissue. We present the properties and the performance of the algorithm under controlled synthetic scenarios. Results show that the method is capable of locating most of the triggering points in scenarios with a fair ratio bet…
An integrated approach based on uniform quantization for the evaluation of complexity of short-term heart period variability: Application to 24 h Hol…
2007
We propose an integrated approach based on uniform quantization over a small number of levels for the evaluation and characterization of complexity of a process. This approach integrates information-domain analysis based on entropy rate, local nonlinear prediction, and pattern classification based on symbolic analysis. Normalized and non-normalized indexes quantifying complexity over short data sequences (â¼300 samples) are derived. This approach provides a rule for deciding the optimal length of the patterns that may be worth considering and some suggestions about possible strategies to group patterns into a smaller number of families. The approach is applied to 24 h Holter recordings of …
Impact of preclinical carotid atherosclerosis on global cardiovascular risk stratification and events in a 10-year follow-up: comparison between the …
2019
Background The aim of the study was to compare three widely used algorithms for stratification of the global cardiovascular risk (GCVR): the Framingham Heart Study (FHS) score, the European systemic coronary risk estimation (SCORE) and the Italian 'Progetto Cuore' (heart project) score. It was also investigated how preclinical carotid atherosclerosis (pre-ATS) might influence the incidence and improve the risk prediction of cerebrovascular and cardiovascular events. Methods Subjects (n = 358) without previous history of cardiovascular disease (CVD) were recruited and the GCVR was calculated for each patient. An ultrasound evaluation of the carotid arteries was also performed. Results Accord…
Electroosmotic effects in the determination of ion mobilities of carrier-free radionuclides in free aqueous electrolyte solutions
2001
A device for on-line electromigration studies of radio-elements in free electrolytes has been tested by measuring the absolute individual ion mobilities of no-carrier-added single charged anions [99mTc]TcO4 - and [18F]F- and differently charged cations [137Cs]Cs+, [57Co]Co2+ and [241Am]Am3+ in inert aqueous electrolytes at 298.1 K. The observed ion mobilities were found to be influenced by electroosmosis in the migration tube. A relation to correct this effect is proposed. In addition, it was shown that the effect of electroosmosis may be suppressed by chemical treatment of the surface of the migration tube.
A Robust and Simple Measure for Quality-Guided 2D Phase Unwrapping Algorithms
2016
Quality-based 2D phase unwrapping algorithms provide one of the best tradeoffs between speed and quality of results. Their robustness depends on a quality map, which is used to build a path that visits the most reliable pixels first. Unwrapping then proceeds along this path, delaying unwrapping of noisy and inconsistent areas until the end, so that the unwrapping errors remain local. We propose a novel quality measure that is consistent, technically sound, effective, fast to compute, and immune to the presence of a carrier signal. The new measure combines the benefits of both the quality-guided and the residue-based phase unwrapping approaches. The quality map is justified from the two diff…
Cartoon filter via adaptive abstraction
2016
We propose a non-parametric methodology to realize abstraction images.The redundant wavelet "a trous" algorithm is applied for details detection.An multi-scale circular median filter is used as a smoothing filter.The proposed algorithm is simple and fast on low-cost entry-level hardware. Abstraction in computer graphics defines a procedure that discriminates the essential information that is worth keeping. Usually details, that correspond to higher frequency components, allow to distinguish otherwise similar images. Vice versa, low frequencies are related to the main information, which are larger structures. Contours themselves may also be identified by high frequencies and separate each pi…
SU-E-J-64: Evaluation of a Commercial EPID-Based in Vivo Dosimetric System in the Presence of Lung Tissue Heterogeneity
2014
Purpose: To study the performance of Dosimetry Check (DC), an EPID-based dosimetry software, which allows performing transit dosimetry, in low density medium, by comparing calculations in-phantom, and analysing results for 15 lung patients. Methods: DC software (v.3.8, pencil beam-based algorithm) has been tested, for plans (Eclipse v.10.0 TPS) delivered in two Varian Clinac iX equipped with aS1000 EPIDs.In the CIRS lung phantom, comparisons between DC and Eclipse (Acuros) were performed for several plans: (1) four field box; (2) square field delivered in arc mode; (3) RapidArc lung patient plan medially centred; (4) RapidArc lung patient plan centred in one lung. Reference points analysed:…