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Saitta  Lorenza  Botta  Marco  Neri  Filippo 《Machine Learning》1993,11(2-3):153-172
This article presents the system WHY, which learns and updates a diagnostic knowledge base using domain knowledge and a set of examples. The a priori knowledge consists of a causal model of the domain that states the relationships among basic phenomena, and a body of phenomenological theory that describes the links between abstract concepts and their possible manifestations in the world. The phenomenological knowledge is used deductively, the causal model is used abductively, and the examples are used inductively. The problems of imperfection and intractability of the theory are handled by allowing the system to make assumptions during its reasoning. In this way, robust knowledge can be learned with limited complexity and a small number of examples. The system works in a first-order logic environment and has been applied in a real domain.  相似文献   
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The paper analyzes food talk and more particularly food assessments produced during dinner conversations videorecorded in naturalistic settings. This focus reveals how expressions of food preferences, taste, and other evaluations are deeply embedded within collective activities, related both to the ongoing conversation and to the management of the meal as a social event. The paper reviews existing interactional studies of dinner conversations, and provides a detailed analysis of the interactional, linguistic and multimodal patterns which characterize the sequential environment in which assessments are produced. It identifies three recurrent contexts: at the beginning of meals, at closings of sequences and topical developments, and at ‘delicate’ moments characterized by emerging disagreements and conflicts. This sequential analysis reveals how taste and food preferences are highly sensitive both to the social occasions and to the organization of turns at talk; analysis shows that not only are assessments systematically positioned within specific sequences in dinner conversations, but also that they can be mobilized in service of other social practices, such as fueling topical talk, reorienting participants’ focus of attention or stopping emerging sequential trajectories.  相似文献   
24.
Memory occupation of geographic data and efficiency of the selection and elaboration algorithms are challenging problems in designing a system for polygonal data processing. They arise basically from the large number of polygon vertices necessary to properly approximate territory maps. Since the number of vertices is determined by the expected resolution, data compression can only be achieved by reducing the memory occupation of each point. On the other hand, more efficient algorithms are obtained if unnecessary operations are carefully avoided: in geographic data processing this is done by precisely delimiting the territory areas to be processed. In this paper, the SECT coding technique is presented, which meets both the above requirements. Its data compression capability is proved with reference to points, lines and regions coding, having considered geographic data of different density. Furthermore, the benefits it ensures in terms of both CPU time and I/O operation savings are discussed.  相似文献   
25.
Metallic transfer from implants does not stop at surrounding tissues, and metallic elements may be transferred by proteins to become lodged in organs far from the implant. This work presents an in vivo study of metallic implant corrosion to measure metallic element accumulation in organs located far from the implant, such as kidneys, livers, lungs and spleens. The studied metallic implant materials were CoCr alloy, Ti, and the experimental alloy MA956 coated with α-alumina. The implants were inserted in the hind legs of Wistar rats. Analysis for Co, Cr, Ti and Al metallic traces was performed after a long exposure time of 12 months by Inductively Coupled Plasma (ICP) with Mass Spectrometry (MS). According to the results, the highest Cr and Ti concentrations were detected in spleens. Co is mainly found in kidneys, since this element is eliminated via urine. Cr and Ti traces increased significantly in rat organs after the long implantation time. The organs of rats implanted with the α-alumina coated experimental MA956 did not present any variation in Al content after 12 months, which means there was no degradation of the alumina layer surface.  相似文献   
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Chronic and recreational use of cocaine has been shown to impair inhibitory output control (response inhibition) but whether input control is also affected is an open question. For the first time, this study compared the ability to perform a cued target-discrimination task that measured inhibition of return (IOR), a reflexive inhibitory mechanism that delays attention from returning to a previously attended location, in adult recreational users and in a cocaine-free-matched sample controlled for age, race, gender distribution, and level of intelligence. Results show that the recreational use of cocaine eliminates IOR, suggesting that input control is strongly impaired. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
28.
Energy Dissipation in Shape Memory Alloy Devices   总被引:1,自引:0,他引:1  
A way of reasoning to reduce the response of a structural system under dynamic excitation is to think in terms of energy dissipation via plastic deformation devices. The concept of recoverable plastic deformation opens the way to the application of smart materials and, in particular, of shape memory alloys (SMAs). The characterization of the TiNi alloy structural component, with a complete definition of its mechanical properties and assembling features, is discussed.  相似文献   
29.
Abstract

I address the current status of dynamical decoupling techniques in terms of required control resources and feasibility. Based on recent advances in both improving the theoretical design and assessing the control performance for specific noise models, I argue that significant progress may still be possible on the road to implementing decoupling under realistic constraints.  相似文献   
30.
Avena sativa L. is a wholegrain cereal and an important edible crop. Oats possesses high nutritional and health promoting values and contains high levels of bioactive compounds, including a group of phenolic amides, named avenanthramides (Avns), exerting antioxidant, anti-inflammatory, and anticancer activities. Epidermal growth factor receptor (EGFR) represents one of the most known oncogenes and it is frequently up-regulated or mutated in human cancers. The oncogenic effects of EGFR include enhanced cell growth, angiogenesis, and metastasis, and down-regulation or inhibition of EGFR signaling has therapeutic benefit. Front-line EGFR tyrosine kinase inhibitor therapy is the standard therapy for patients with EGFR-mutated lung cancer. However, the clinical effects of EGFR inhibition may be lost after a few months of treatment due to the onset of resistance. Here, we showed the anticancer activity of Avns, focusing on EGFR activation and signaling pathway. Lung cancer cellular models have been used to evaluate the activity of Avns on tumor growth, migration, EMT, and anoikis induced by EGF. In addition, docking and molecular dynamics simulations showed that the Avns bind with high affinity to a region in the vicinity of αC-helix and the DGF motif of EGFR, jeopardizing the target biological function. Altogether, our results reveal a new pharmacological activity of Avns as EGFR tyrosine kinase inhibitors.  相似文献   
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