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111.
Preschool children at familial risk for reading disability were assessed on cognitive and linguistic variables and compared with preschoolers without familial risk. Risk children displayed performance profiles resembling those of older children with reading disability. Each group received intensive instruction in phonemic awareness and structured book reading. Instructed risk children made somewhat smaller gains than the nonrisk and required more teaching sessions to reach criterion. Rhyme and phoneme awareness predicted instruction outcome levels, and vocabulary and verbal short-term memory predicted number of teaching sessions to criterion. In kindergarten, the nonrisk group outperformed the risk group on reading and spelling, although the risk group reached grade-appropriate levels. At-risk children can be helped by appropriate preschool instruction, but they require more sustained teaching than nonrisk preschoolers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
112.
The revelation of an affair is often an emotionally explosive event for a couple, yet little is known about specific individual and relationship factors that accompany infidelity. The present study examined the qualities of individuals and couples that differentiate couples with (n = 19) and without (n = 115) infidelity using couples from a randomized clinical trial of marital therapy. Findings indicated that couples with infidelity showed greater marital instability, dishonesty, arguments about trust, narcissism, and time spent apart. Gender also proved to be a significant moderator of several effects. Men who had participated in affairs showed increased substance use, were older, and were more sexually dissatisfied. Results offer initial clues to concomitants of affairs for couple therapists. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
113.
The authors tested whether adherence to simultaneous health behavior changes was unitary or domain specific among 76 women who modified smoking, eating, and physical activity to accomplish smoking cessation plus weight control. Random-effects regression analyses showed that adherence to both smoking and diet plans declined linearly and covaried positively; their association tended to grow stronger over time. In contrast, physical activity plan adherence did not change over time and was unrelated to other domains. At the end of treatment, 65%, 30.5%, and 25% adhered well or excellently to smoking, diet, and activity treatments, respectively. Findings support both unitary and domain-specific aspects of adherence and suggest that among smokers, smoking and eating behaviors may have similarities unshared by physical activity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
114.
115.
SATCHMORE was introduced as a mechanism to integrate relevancy testing with the model-generation theorem prover SATCHMO. This made it possible to avoid invoking some clauses that appear in no refutation, which was a major drawback of the SATCHMO approach. SATCHMORE relevancy, however, is driven by the entire set of negative clauses and no distinction is accorded to the query negation. Under unfavorable circumstances, such as in the presence of large amounts of negative data, this can reduce the efficiency of SATCHMORE. In this paper we introduce a further refinement of SATCHMO called SATCHMOREBID: SATCHMORE with BIDirectional relevancy. SATCHMOREBID uses only the negation of the query for relevancy determination at the start. Other negative clauses are introduced on demand and only if a refutation is not possible using the current set of negative clauses. The search for the relevant negative clauses is performed in a forward chaining mode as opposed to relevancy propagation in SATCHMORE which is based on backward chaining. SATCHMOREBID is shown to be refutationally sound and complete. Experiments on a prototype SATCHMOREBID implementation point to its potential to enhance the efficiency of the query answering process in disjunctive databases. Donald Loveland, Ph.D.: He is Emeritus Professor of Computer Science at Duke University. He received his Ph.D. in mathematics from New York University and taught at NYU and CMU prior to joining Duke in 1973. His research in automated deduction includes defining the model elimination proof procedure and the notion of linear resolution. He is author of one book and editor/co-editor of two other books on automated theorem proving. He has done research in the areas of algorithms, complexity, expert systems and logic programming. He is an AAAI Fellow, ACM Fellow and winner of the Herbrand Award in Automated Reasoning. Adnan H. Yahya, Ph.D.: He is an associate professor at the Department of Electrical Engineering, Birzeit University, Palestine. He received his Diploma and PhD degrees from St. Petersburg Electrotechnical University and Nothwestern University in 1979 and 1984 respectively. His research interests are in Artificial Intelligence in general and in the areas of Deductive Databases, Logic Programming and Nonmonotonic Reasoning in particular. He had several visiting appointments at universities and research labs in the US, Germany, France and the UK. Adnan Yahya is a member of the ACM, IEEE and IEEE Computer Society.  相似文献   
116.
Stand delineation and species composition estimation are cornerstones of forest inventory mapping and key elements to forest management decision making. Improved mapping techniques are constantly being sought in terms of speed, consistency, accuracy, level of detail, and overall effectiveness. Semi-automated analysis of high-resolution imagery at the individual tree crown level may offer such benefits. Methods, however, need to be developed and tested under a variety of forest conditions.High-resolution (60 cm) multispectral airborne imagery was acquired over a predominantly young conifer forest and plantation test area on the west coast of Canada. Automated tree isolation algorithms were applied to the data in order to delineate tree crowns or clusters of crowns. An object-oriented single tree classification was conducted using a maximum likelihood classifier. Stands of similar species composition, closure, and stem density were defined through a sequence that first generated images of these parameters from the automated delineation and classification, used these as input to an unsupervised classification, and then filtered and smoothed the resulting classification clusters. Because of the dense nature of the stands and small crowns on the site, the isolation process often delineated clusters of several trees. Species classification accuracy was determined by comparing the average stand composition from the automated technique to that derived from ground transects or plots. Species classification was good, with average composition error (difference between field measured and automated composition) over all 16 test stands being 7.25%. Most errors for individual species in stands were below 20%, but a few were up to 30%. The automatically generated stand boundaries mimicked well those of known plantation and interpreted inventory boundaries. The automated technique created a few larger stands and some additional small stands in areas of complex forest structure. Overall, for the young fairly uniform stands of the site, both stand delineation and species composition estimation were of a quality suitable for operational use in inventory and forest management. Further development and testing is needed to extend results to situations covering large areas, multiple flight lines, varied topography, and different forest conditions.  相似文献   
117.
Optimal control of nonlinear systems: a predictive control approach   总被引:2,自引:0,他引:2  
A new nonlinear predictive control law for a class of multivariable nonlinear systems is presented in this paper. It is shown that the closed-loop dynamics under this nonlinear predictive controller explicitly depend on design parameters (prediction time and control order). The main features of this result are that an explicitly analytical form of the optimal predictive controller is given, on-line optimisation is not required, stability of the closed-loop system is guaranteed, the whole design procedure is transparent to designers and the resultant controller is easy to implement. By establishing the relationship between the design parameters and time-domain transient, it is shown that the design of an optimal generalised predictive controller to achieve desired time-domain specifications for nonlinear systems can be performed by looking up tables. The design procedure is illustrated by designing an autopilot for a missile.  相似文献   
118.
Solid modeling of 4-axis wire EDM cut geometry   总被引:4,自引:0,他引:4  
NC verification has been widely used in milling and turning machining, but the implementation of NC verification for wire electrical discharge machine (wire EDM) has received little attention, made difficult by the characteristics of geometry cut by the thin wire. For an NC verification system, the speed and the accuracy of are two of the most critical issues. In this paper, a novel solid modeling method, which utilizes a dual quadtree structure and a boundary representation, is applied to modeling the parts cut by a wire EDM. In this implementation, two extended quadtrees on the top and bottom surfaces of the stock are first created. Special quadtree nodes are introduced into the dual quadtree structure to model the features associated with the almost coincident surfaces left by a thin wire. The region swept by a wire in each move is generated based on the diameter of the wire, spark gap size and the paths. The overall geometry of the part is represented by a boundary representation which is updated by means of efficient Boolean operations of extended quadtrees. The free-falling objects which may damage the machine tool can be detected. Dimensional inspection and feature detection can be made with the solid model representing the machined part. The system has demonstrated very promising speed and accuracy.  相似文献   
119.
This paper presents a computer-based method for the optimal design of three-dimensional Reinforced Concrete (RC) structures having beams subjected to shear force and bending moment, columns subjected to biaxial moments, biaxial shears and axial loads, and shear walls subjected to pure shear. Regarding the beams and columns, the design variables are the width, depth and area of longitudinal reinforcement of member sections. The design variables for the shear walls are the thickness of the wall, the area of vertical reinforcement, horizontal distance between the vertical stirrups, the area of horizontal reinforcement, vertical space between the horizontal stirrups, and the area of vertical flexural reinforcement. The Optimality Criteria (OC) method is applied to minimize the cost of the concrete, steel and formwork for the structure. ACI code [1] provisions concerning the strength and ductility of beams, columns and shear walls are taken as constraints. The constraints also impose upper and lower bounds on the dimensions of beams and columns, and on shear wall thickness, reinforcement area and the maximum and minimum vertical and horizontal spaces between the stirrups of the shear walls. Sensitivity analysis is conducted for both internal forces and the capacities of the sections of the beams, columns and shear walls. The features of the design method are illustrated by a solved example.  相似文献   
120.
Uses of stored skill-models to accelerate simulator-based real-time training in a control skill are discussed. A real-time coach must deliver advice at three levels: (1) what to do next, (2) what to watch for, and (3) what went wrong. Human learning and machine learning results are presented using different screen representations of a pole-and-cart balancing task.  相似文献   
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