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61.
Nowadays is very common the presence of tall buildings in the business centres of the main cities of the world. Such buildings require the installation of numerous lifts that are coordinated and managed under a unique control system. Population working in the buildings follows a similar traffic pattern generating situations of traffic congestion. The problem arises when a passenger makes a hall call wishing to travel to another floor of the building. The dispatching of the most suitable car is the optimization problem we are tackling in this paper. We develop a viral system algorithm which is based on a bio-inspired virus infection analogy to deal with it. The viral system algorithm is compared to genetic algorithms, and tabu search approaches that have proven efficiency in the vertical transportation literature. The experiments undertaken in tall buildings from 10 to 24 floors, and several car configurations from 2 to 6 cars, provide valuable results and show how viral system outperforms such soft computing algorithms.  相似文献   
62.
63.
To increase the potential and better exploring of grape seeds that are an important wine-industrial waste, oils of ten traditional Portuguese grape varieties were evaluated in relation to their vitamin E content (tocopherols and tocotrienols), fatty acid profile, as well as, antioxidant properties. Our results showed that the grape-seed oils were a good source of γ-tocotrienol (499–1575 mg/kg), α-tocopherol (85.5–244 mg/kg) and α-tocotrienol (69–319 mg/kg). Concerning fatty acid profile, linoleic (C18:2cc), oleic (C18:1), palmitic (C16:0) and stearic (C18:0) acids were the predominant. Grape-seed oils demonstrated to be a good source of polyunsaturated fatty acids (PUFAs) (63.64–73.53%), whereas monounsaturated fatty acid (MUFA) and saturated fatty acid (SFA) ranged between 14.19–21.29% and 11.64–14.94%, respectively. Interesting values of DPPH and ABTS radical scavenging activities were also obtained. This study demonstrated that these seeds may be reused and their oils incorporated in other food products, taking into account the compounds with positive effects on human health that are present in their composition.  相似文献   
64.
Response surface methodology was used to find the optimum ethanol concentration and temperature which maximises the antioxidant activity (AA) of hydroalcoholic extracts from aerial parts of Bidens pilosa L. A rotatable central composite design was used, and the extracts were characterised by the determination of solid concentration (SC), total flavonoid (TFC) and total polyphenol content (TPC). AA was determined through 2,2′‐azinobis (3‐ethylbenzothiazoline‐6‐sulphonic acid) diammonium salt (ABTS) and 2,2‐diphenyl‐1‐pycrylhydrazyl (DPPH) radical scavenging activity. Mathematical models showed the significant effects of each variable and allowed to select the optimum conditions of ethanol concentration (62.7%) and extraction temperature (66.2 °C). The optimised extract presented an AA of 804.9 ± 12.2 Trolox equivalent antioxidant capacity (TEAC) dry base (d.b.) for DPPH and 515.8 ± 31.8 TEAC d.b. for ABTS. It was observed that both TFC and TPC showed a good correlation with AA of the extracts.  相似文献   
65.
The properties of poly(alkylthiophenes) in solution are found to have a profound impact on the self assembly process and thus the microstructural and electrical properties of the resultant thin films. Ordered supramolecular precursors can be formed in regioregular poly(3‐hexylthiophene) (P3HT) solutions through the application of low intensity ultrasound. These precursors survive the casting process, resulting in a dramatic increase in the degree of crystallinity of the thin films obtained by spin coating. The crystallinity of the films is tunable, with a continuous evolution of mesoscale structures observed as a function of ultrasonic irradiation time. The photophysical properties of P3HT in solution as well in the solid state suggest that the application of ultrasound leads to a π stacking induced molecular aggregation resulting in field effect mobilities as high as 0.03 cm2 V?1 s?1. A multiphase morphology, comprising short quasi‐ordered and larger, ordered nanofibrils embedded in a disordered amorphous phase is formed as a result of irradiation for at least 1 min. Two distinct regions of charge transport are identified, characterized by an initial sharp increase in the field effect mobility by two orders of magnitude due to an increase in crystallinity up to the percolation limit, followed by a gradual saturation where the mobility becomes independent of the thin film microstructure.  相似文献   
66.
This paper studies connectivity maintenance of robotic networks that communicate at discrete times and move in continuous space. We propose a distributed coordination algorithm that allows the robots to decide whether a desired collective motion breaks connectivity. We build on this procedure to design a second coordination algorithm that allows the robots to modify a desired collective motion to guarantee that connectivity is preserved. These algorithms work under imperfect information caused by delays in communication and the robots’ mobility. Under very outdated information, the proposed algorithms might prevent some or all of the robots from moving. We analyze the correctness of our algorithms by formulating them as games against a hypothetical adversary who chooses system states consistent with observed information. The technical approach combines tools from algebraic graph theory, linear algebra, and nonsmooth analysis.  相似文献   
67.
OBJECTIVE: To determine the frequency of dysphagia in CVA, its natural history and value as a risk factor of respiratory infection, malnutrition and death. PATIENTS AND METHODS: A prospective study was made of 187 consecutive patients with cerebrovascular accidents (CVA). A standardized test for dysphagia was done during the first two days of the illness and repeated three days a week. The levels of urea, total proteins and albumin were determined on admission and on discharge. The patients were questioned by phone after 6 months. RESULTS: There was dysphagia of liquids in 36.4% of the patients. The incidence of dysphagia for semisolids was of the same frequency but more severe. Coma was the cause of inability to swallow in 25.7% of the patients. During their stay in hospital one third of the patients with dysphagia died, one third became normal and one third still had dysphagia when they were discharged. After one week, one, three and six months respectively, the cure rate for dysphagia was 29.4%, 4.1%, 55.9% and 55.9%, and survival 83.8%, 67.6%, 61.8% and 60.3%. Thus after 6 months only 3 patients (4.4%) were alive and dysphagic. Half of the 'cures' occurred in the first week, and none occurred after more than 77 days. As compared to the non-dysphagic patients, the dysphagic patients had 10 times more risk of respiratory infection, 18 times higher risk of death, greater loss of albumin and less loss of urea. CONCLUSIONS: There is a high prevalence of dysphagia in CVA and although functional prognosis is not unfavorable, respiratory infections, malnutrition and death are frequent.  相似文献   
68.
Predicting corporate failure is an important management science problem. This is a typical classification question where the objective is to determine which indicators are involved in the failure/success of a corporation. Despite the importance of this problem, until now only classical machine learning tools have been considered to tackle this classification task. The objective of this paper is twofold. On the one hand, we introduce novel discerning measures to rank independent variables in a generic classification task. On the other hand, we apply boosting techniques to improve the accuracy of a classification tree. We apply this methodology to a set of European firms, considering the usual predicting variables such as financial ratios, as well as including novel variables rarely used before in corporate failure prediction, such as firm size, activity and legal structure. We show that our approach decreases the generalization error about thirty percent with respect to the error produced with a classification tree. In addition, the most important ratios deal with profitability and indebtedness, as is usual in failure prediction studies. E. A. Cortés · M. G. Martínez · N. G. Rubio. The authors teach Statistics at the Faculty of Economic and Business Sciences in the University of Castilla-La Mancha. Esteban Alfaro completed his degree in Business in 1999 and got his Ph.D. in Economics in 2005, both in the University of Castilla-La Mancha. His thesis dealt with the application of ensemble classifiers to corporate failure prediction. Matías Gámez got his degree in Mathematics at the University of Granada in 1991 and finished a Master in Applied Statistics a year after. He completed his Ph.D. in Economics at the University of Castilla-La Mancha in 1998 on the application of geo-statistical techniques to the estimation of housing prices. Noelia García got her degree in Economics at the University of Madrid (UAM) in 1996 and completed her Ph.D. in Economics in 2004 on the construction of an intelligent and automated system for property valuation through the combination of neural nets and a geographic information system (GIS). Current research deals with spatial statistics and the combination of classifiers (decision trees and neural nets) for solving heated topics in the Economics.  相似文献   
69.
A numerical and experimental assessment of the compression test in the split Hopkinson pressure bar (SHPB) has been made. The DYNA2D finite element code was employed in the numerical part. The aim of the work was to establish the influence of an important reduction in the specimen diameter on the results. To this end, several numerical experiments were carried out with different diameters. Experimental measurements using the SHPB technique were also performed. The material studied was the 7017 T73 aluminium alloy. In the simulations, stress histories were registered at different places in the incident and output bars, as well as in the test specimen. Numerical simulations show important three-dimensional effects in the SHPB, increasing for smaller diameters. Experiments show the same tendencies evinced by the numerical simulation. Care must be taken to minimize them to achieve the desirable uniaxial stress condition on the specimen.  相似文献   
70.
Reports an error in the original article by J. M. Johns et al (Behavioral Neuroscience, 1994[Feb], Vol 108[1], 107–212). On page 108, in the Results, Maternal Behavior, the phrase in parentheses, "(8 min to crouch for 8 min or more of 30 min)' should read: "(6 min to crouch for 8 min or more of 30 min).' On page 109, the label on the upper right panel of Figure 1, "Percent That Crouch in 8 Minutes,' should read: "Percent That Crouch in 6 Minutes.' (The following abstract of this article originally appeared in record 1994-24731-001.) Pregnant rats (N?=?17) were treated either throughout gestation (Gestational Day 1–20) with 30 mg/kg per day (chronic cocaine) or with 1 15-mg/kg dose immediately following parturition (acute cocaine). Chronic and acute cocaine treatment delayed or diminished the postpartum onset of some components of maternal behavior, and chronically treated dams were significantly more aggressive toward a male intruder than acute cocaine-treated or saline-treated dams. Cocaine increased the latency to crouch over pups and decreased crouch duration during a 30-min observation period that immediately followed parturition. Latencies to nest build were also longer in more chronic cocaine-treated dams than in saline controls.… (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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