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排序方式: 共有295条查询结果,搜索用时 31 毫秒
21.
Yael Abarbanel-Vinov Neta Aizenbud-Reshef Ilan Beer Cindy Eisner Daniel Geist Tamir Heyman Iris Reuveni Eran Rippel Irit Shitsevalov Yaron Wolfsthal Tali Yatzkar-Haham 《Formal Methods in System Design》2001,19(1):35-44
We examine IBM's exploitation of formal verification using RuleBase—a formal verification tool developed by the IBM Haifa Research Laboratory. The goal of the paper is methodological. We identify an integrated methodology for the deployment of formal verification which involves three complementary modes: architectural verification, block-level verification, and design exploration. 相似文献
22.
This paper presents a new reinforcement learning algorithm that enables collaborative learning between a robot and a human.
The algorithm which is based on the Q(λ) approach expedites the learning process by taking advantage of human intelligence and expertise. The algorithm denoted as
CQ(λ) provides the robot with self awareness to adaptively switch its collaboration level from autonomous (self performing, the
robot decides which actions to take, according to its learning function) to semi-autonomous (a human advisor guides the robot
and the robot combines this knowledge into its learning function). This awareness is represented by a self test of its learning
performance. The approach of variable autonomy is demonstrated and evaluated using a fixed-arm robot for finding the optimal
shaking policy to empty the contents of a plastic bag. A comparison between the CQ(λ) and the traditional Q(λ)-reinforcement learning algorithm, resulted in faster convergence for the CQ(λ) collaborative reinforcement learning algorithm. 相似文献
23.
A brief proton pulse technique, based on photo-excitation of pyranine, was employed for measuring the protonation dynamics of cytochrome c in aqueous solutions. Time-resolved monitoring of the protonation state of the pyranine anion yielded detailed information from which the temporal state protonation of the surface carboxylates and histidine residues were deduced. The surface groups were found to be coupled by electrostatic interaction where the state of protonation of one affects the pK of the others. In the same sense, altering the charge distribution of a protein by a redox reaction affects the reactivity of the surface groups with protons in the bulk. The surface groups can exchange protons among themselves at a very high rate. The velocities of these reactions are functions of the connectivity between the proton binding sites. A single proton exchange reaction between the surface groups could be identified as the proton exchange between H26 and E44. The reaction is fast and affected by the redox state of the protein. It is proposed that the enhanced rate of this reaction is coupled with transient conformational changes that are not noticeable in time-averaging measurements such as X-ray diffraction or NMR. 相似文献
24.
In recent years, much interest has been given to presence of micropollutants in municipal wastewater, some of which are suspected to be endocrine disruptors, toxic or carcinogenic. Much less attention has been paid to their presence in greywater. The present research studies the diurnal patterns of micropollutants in greywater and computes their daily loads. Monitoring was carried-out using auto-controlled sampling system, designed to overcome the erratic greywater generation. Two main generation periods were identified: morning (5:00–11:00) and evening-night (18:00–2:00), contributing about 20% and >50% of daily greywater discharge, respectively. Average specific daily greywater discharge was 57 L p?1d?1, which matches reported value for greywater generated by showers and washbasins in Israel. The most frequently detected micropollutants in this study were methylparben (preservative), galaxolide (fragrance) and oxybenzone (UV-filter), which are common ingredients in many personal care-products. Their daily loads were 2, 840, 1, 887 and 728 µg p?1d?1, respectively. 相似文献
25.
Nevena Kaličanin Dr. Ana Marija Balaž Dr. Olivera Prodanović Prof. Dr. Radivoje Prodanović 《Chembiochem : a European journal of chemical biology》2023,24(20):e202300414
The aim of this research was to prove the function of the putative opine dehydrogenase from Desulfohalobium retbaense and to characterize the enzyme in terms of functional and kinetic parameters. A putative opine dehydrogenase was identified from a metagenomic library by a sequence-based technique search of the metagenomic library, and afterward was successfully heterologously produced in Escherichia coli. In order to examine its potential for applications in the synthesis of secondary amines, first the substrate specificity of the enzyme towards different amino donors and amino acceptors was determined. The highest affinity was observed towards small amino acids, preferentially L-alanine, and when it comes to α-keto acids, pyruvate proved to be a preferential amino acceptor. The highest activity was observed at pH 6.5 in the absence of salts. The enzyme showed remarkable stability in a wide range of experimental conditions, such as broad pH stability (from 6.0–11.0 after 30 min incubation in buffers at a certain pH), stability in the presence of NaCl up to 3.0 M for 24 h, it retained 80 % of the initial activity after 1 h incubation at 45 °C, and 65 % of the initial activity after 24 h incubation in 30 % dimethyl sulfoxide. 相似文献
26.
Objective: This study was designed to evaluate the association between marital distress and mental health service utilization in a population-based sample of men and women (N = 1,601). Method: The association between marital distress and mental health care service utilization was evaluated for overall mental health service utilization and for specific sectors of treatment providers, including psychiatrist, other mental health provider, other medical provider, and religious services provider. Interviews were used to assess past-year service utilization and presence of anxiety, mood, and substance use disorders. Results: Approximately 12% of married individuals sought help for problems with their emotions, nerves, or substance use during the 12 months preceding the interview. Marital distress was significantly associated with (a) overall mental health service utilization and service utilization provided by each of the sectors of providers when controlling for demographic variables and (b) overall mental health service utilization and receiving treatment from a psychiatrist when additionally controlling for past-year anxiety, mood, or substance use disorders. There was little evidence that the associations between marital distress and service utilization were moderated by gender or presence of psychiatric disorders. Conclusion: The finding that marital distress is associated with greater mental health care service utilization suggests that clinicians should assess both individual and relationship factors among individuals presenting for treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
27.
Remez Robert E.; Dubowski Kathryn R.; Broder Robin S.; Davids Morgana L.; Grossman Yael S.; Moskalenko Marina; Pardo Jennifer S.; Hasbun Sara Maria 《Canadian Metallurgical Quarterly》2011,37(3):968
Speech remains intelligible despite the elimination of canonical acoustic correlates of phonemes from the spectrum. A portion of this perceptual flexibility can be attributed to modulation sensitivity in the auditory-to-phonetic projection, although signal-independent properties of lexical neighborhoods also affect intelligibility in utterances composed of words. Three tests were conducted to estimate the effects of exposure to natural and sine-wave samples of speech in this kind of perceptual versatility. First, sine-wave versions of the easy and hard word sets were created, modeled on the speech samples of a single talker. The performance difference in recognition of easy and hard words was used to index the perceptual reliance on signal-independent properties of lexical contrasts. Second, several kinds of exposure produced familiarity with an aspect of sine-wave speech: (a) sine-wave sentences modeled on the same talker; (b) sine-wave sentences modeled on a different talker, to create familiarity with a sine-wave carrier; and (c) natural sentences spoken by the same talker, to create familiarity with the idiolect expressed in the sine-wave words. Recognition performance with both easy and hard sine-wave words improved after exposure only to sine-wave sentences modeled on the same talker. Third, a control test showed that signal-independent uncertainty is a plausible cause of differences in recognition of easy and hard sine-wave words. The conditions of beneficial exposure reveal the specificity of attention underlying versatility in speech perception. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
28.
Bhanu K. Patibandla Akshita Narra Ranil DeSilva Varun Chawla Yael Vin Robert S. Brown Alexander S. Goldfarb‐Rumyantzev 《Hemodialysis international. International Symposium on Home Hemodialysis》2014,18(1):118-126
The benefits of an arteriovenous fistula (AVF) as the preferred vascular access for hemodialysis have been clearly demonstrated. However, only about 20% of patients in the United States initiate hemodialysis with an AVF. In this study, we assessed whether disparities exist in the type of first hemodialysis access placed prior to dialysis start (rather than that used at dialysis initiation), to detect whether certain disadvantaged groups might have lower likelihood of AVF placement. Study cohort of 118,767 incident hemodialysis patients ≥67 years of age (1/2005–12/2008) derived from the United States Renal Data System was linked with Medicare claims data to identify the type of initial access placed predialysis. We used logistic regression model with outcome being the initial predialysis placement of an AVF as opposed to an arteriovenous graft or a central venous catheter. Increasing age, female sex, black race, lower body mass index, urban location, certain comorbidities, and shorter pre–end‐stage renal disease nephrology care are all associated with a significantly lower likelihood of AVF placement as initial access predialysis. Our study suggests the presence of significant disparities in the placement of an AVF as initial hemodialysis vascular access. We suggest that additional attention should be paid to these patient groups to improve disparities by patient education, earlier referral, and close follow‐up. 相似文献
29.
Dj. Kalić Z. Radaković Z. Lazarević R. Radosavljević 《Electrical Engineering (Archiv fur Elektrotechnik)》1993,76(6):457-468
Contents Under usual assumptions the equations describing thermal phenomena in a transformer are established. Without neglecting any substantially important factor, algorithms are developed for predicting the temperatures in critical spots in non-stationary states occurring either in practice or in load/time diagrams. This paper suggests the determinaton of conductances dependent on temperature and constant capacitances of equivalent thermal circuits of a transformer. They are based on a small number of experiments (as simple as possible) and on a parameter estimation procedure. In such a way the temperatures of transformer parts in different transient states can be determined by computer simulation established on equivalent circuits, so the operators in power and sub-stations will be able to load their transformers close to the permitted limit. It is felt that this paper may give a stimulation for a possible revision of IEC rules.
Ermittlung charakteristischer Temperaturen von Leistungs-Öl-Transformatoren im nichtstationären Betrich
Übersicht Die Gleichungen des Temperaturverhaltens eines Transformators werden unter den üblichen Annahmen aufgestellt. Es werden Algorithmen entwickelt, welche die Vorausbestimmung der Temperatur an kritischen Stellen bei nichtstationärem Betrieb erlauben. Vorgeschlagen wird die Bestimmung der temperaturabhängigen und-unabhängigen Parameter auf Grund von wenigen und einfachen Messungen. Damit kann das Personal in Verteilerstationen in die Lage versetzt werden, mit Hilfe von PC's die Belastung der Transformatoren bis zu den zulässigen Grenztemperaturen auszudehnen. Die Autoren möchten damit einen Anstoß zu einer möglichen Überarbeitung von IEC-Vorschriften geben.相似文献
30.
Activity restriction is known to mediate the disease-depression relationship. Data from 423 older Israeli adults showed that having to give up activities because of failing health was related to more depressive symptoms (DS), whereas satisfactorily replacing these activities was related to DS levels comparable to those of healthier older adults. Giving up and replacing activities mediated, in part, the effect of functional limitations on DS, after controlling for health status, demographics, and resources. Such questions about activities given up and replaced could contribute to the means of assessing the extent and impact of functional limitations on older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献