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61.
Dorit Baras Shai Fine Laurent Fournier Dan Geiger Avi Ziv 《International Journal on Software Tools for Technology Transfer (STTT)》2011,13(3):247-261
Closing the feedback loop from coverage data to the stimuli generator is one of the main challenges in the verification process.
Typically, verification engineers with deep domain knowledge manually prepare a set of stimuli generation directives for that
purpose. Bayesian networks based CDG (coverage directed generation) systems have been successfully used to assist the process
by automatically closing this feedback loop. However, constructing these CDG systems requires manual effort and a certain
amount of domain knowledge from a machine learning specialist. We propose a new method that boosts coverage in the early stages
of the verification process with minimal effort, namely a fully automatic construction of a CDG system that requires no domain
knowledge. Experimental results on a real-life cross-product coverage model demonstrate the efficiency of the proposed method. 相似文献
62.
Robin Murphy Dylan Shell Amy Guerin Brittany Duncan Benjamin Fine Kevin Pratt Takis Zourntos 《Autonomous Robots》2011,30(2):143-156
Seven flying robot “fairies” joined human actors in the Texas A&;M production of William Shakespeare’s A Midsummer Night’s Dream. The production was a collaboration between the departments of Computer Science and Engineering, Electrical and Computer Engineering, and Theater Arts. The collaboration was motivated by two assertions. First, that the performing arts have principles for creating believable agents that will transfer to robots. Second, the theater is a natural testbed for evaluating the response of untrained human groups (both actors and the audience) to robots interacting with humans in shared spaces, i.e., were believable agents created? The production used two types of unmanned aerial vehicles, an AirRobot 100-b quadrotor platform about the size of a large pizza pan, and six E-flite Blade MCX palm-sized toy helicopters. The robots were used as alter egos for fairies in the play; the robots did not replace any actors, instead they were paired with them. The insertion of robots into the production was not widely advertised so the audience was the typical theatergoing demographic, not one consisting of people solely interested technology. The use of radio-controlled unmanned aerial vehicles provides insights into what types of autonomy are needed to create appropriate affective interactions with untrained human groups. The observations from the four weeks of practice and eight performances contribute (1) a taxonomy and methods for creating affect exchanges between robots and untrained human groups, (2) the importance of improvisation within robot theater, (3) insights into how untrained human groups form expectations about robots, and (4) awareness of the importance of safety and reliability as a design constraint for public engagement with robot platforms. The taxonomy captures that apparent affect can be created without explicit affective behaviors by the robot, but requires talented actors to convey the situation or express reactions. The audience’s response to robot crashes was a function of whether they had the opportunity to observe how the actors reacted to robot crashes on stage, suggesting that pre-existing expectations must be taken into account in the design of autonomy. Furthermore, it appears that the public expect robots to be more reliable (an expectation of consumer product hardening) and safe (an expectation from product liability) than the current capabilities and this may be a major challenge or even legal barrier for introducing robots into shared public spaces. These contributions are expected to inform design strategies for increasing public engagement with robot platforms through affect, and shows the value of arts-based approaches to public encounters with robots both for generating design strategies and for evaluation. 相似文献
63.
The presence of Cu precipitates counteracts the cyclic softening present in ordinary quenched and tempered steels. This is expected to result in an increase in fatigue limit. The fatigue crack propagation rate (dc/dN) at constant K in the Cu-C steels was shown to depend on heat-treatment and carbon content. To maximize yield strength and minimize ¦da/dN¦K
for tempering at 500° C, one must choose a low C content and temper for a short time; ¦da/dN¦K in 0.28 wt % C-1.45 wt % Cu tempered for 13 min was one-third that for 0.45 wt % C-1.45 wt% Cu tempered for 200 min. There is also an advantage in adding Cu while simultaneously lowering the Ccontent. The dc/dN data are discussed in terms of the yield strength and the energy to form a unit area of fatigue crack, U, which was measured using foil strain gauges. The quantity (¦dc/dN ¦K
y
2
U) where
y
is the cyclic yield stress, was found to be nearly constant. In the 0.28 wt % C-1.45wt % Cu alloy, short ageing times at 500° C resulted in greater resistance to initiation of cracks at notches for low Ks than long ageing times. 相似文献
64.
Predictability of healing of ischemic leg ulcers by radioisotopic and Doppler ultrasonic examination
In a prospective study of twenty-six patients with ischemic ulcerations of the lower extremity, the predictive reliability with regard to spontaneous wound healing of diabetes, pedal pulses, ankle blood pressure (ABP) as measured by doppler ultrasound, and "leg ulcer scan" as performed by the intra-arterial injection of radioactive albumin was evaluated. The results suggest that only the leg ulcer scan is significantly reliable in predicting the likelihood of spontaneous healing. The following format for the evaluation of the ischemic leg ulcer is therefore suggested: (1) If pedal pulses are present, a three week trial of conservative therapy is indicated before further evaluation. (2) If the doppler ABP is 50 mm Hg or less, the ulcer will not heal spontaneously. (3) Leg ulcer scan is indicated: (a) in the absence of pedal pulses if ABP is less than 50 mm Hg; (b) in the presence of pedal pulses if there is no evidence of spontaneous healing after three weeks of conservative therapy. 相似文献
65.
Narayanan Nandakumar S.; Prabhakaran Vivek; Bunge Silvia A.; Christoff Kalina; Fine Eric M.; Gabrieli John D. E. 《Canadian Metallurgical Quarterly》2005,19(2):223
Neuroimaging studies have been inconclusive in characterizing the role of the prefrontal cortex (PFC) for maintaining increasingly larger amounts of information in working memory (WM). To address this question, the authors collected event-related functional MRI data while participants performed an item-recognition task in which the number of to-be-remembered letters was parametrically modulated. During maintenance of information in WM, the dorsolateral and the ventrolateral PFC exhibited linearly increasing activation in response to increasing WM load. Prefrontal regions could not be distinguished from one another on the basis of load sensitivity, but the dorsolateral PFC had stronger functional connectivity with the parietal and motor cortex than the ventrolateral PFC. These results suggest an increasingly important role for the PFC in actively maintaining information as the amount of that information increases. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
66.
67.
Interviews with African American and White American elders capture the immediate power of the Brown v. Board of Education (1954) decision and the biography of its impact over time. This article reviews the lived experience of the decision and theorizes 3 threats to sustainability that ruthlessly undermined the decision over time: (a) the unacknowledged and enormous sacrifice endured by the African American community in the name of desegregation; b) the violent and relentless resistance to the decision by government officials, educators, and many White community members; and (c) the dramatic shrinkage of the vision of Brown from the dismantling of White supremacy to a technical matter of busing. Implications are drawn for the study of desegregation and for the study of sustainability of social justice more broadly. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
68.
研制一种新型耐硫、抗胶质镍系加氢催化剂,在固定床液相加氢装置评价催化剂性能,考察催化剂制备方法、载体和助剂种类对裂解C9馏分加氢性能的影响。结果表明,浸渍法制备的催化剂活性较高,添加稀土分子筛及助剂后的催化剂低温活性更好。在反应器入口温度(60~80) ℃、空速1.5 h-1、反应压力3.0 MPa和氢油体积比500∶1条件下,对催化剂进行240 h稳定性实验,裂解C9馏分的双烯值由5.3 g-I2·(100g)-1降至约0.60 g-I2·(100g)-1,溴值由57.2 g-Br2·(100g)--1降至约25.5 g-Br2·(100g)-1,稳定性良好。 相似文献
69.
70.
Richard C. Morey Donna L. Retzlaff-Roberts David J. Fine 《International Transactions in Operational Research》1994,1(3):285-292
One of the focal points of discussion among firms in the service sector concerns the level of service delivered and its value. In the hospital sector, an important aspect of the level of service relates to the level of quality of care delivered. We undertake an empirical study of 300 U.S. hospitals to evaluate their relative ‘service efficiency’ using the techniques of so-called allocative efficiency. This method estimates the potential improvement in service, estimates the ideal cost shares of the various resources, and provides the ‘peer group’ members to which the unit is being compared. Utilizing this information, the method proposed for units to improve involves two chief mechanisms. The first is a reallocation of cost shares among the various resource or input types (e.g. no increase in hospital budget). The second involves adopting the management practices used by peer group members. Over all 300 hospitals, a marked improvement potential was found for well over half. Of the poorest performers there appears to be some indication that a larger cost share was needed for face-to-face contact with patients (nursing) and a smaller share for personnel who do not deal with patients directly (lab technicians, non-physician administrators, etc.). 相似文献