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71.
Life stress was studied in relation to postrecovery attrition, symptom course, and recurrence of depression over 3 yrs. Participants were 67 individuals with recurrent depression who had responded to treatment. Life stress was assessed for the prior 12 wks at acute treatment entry (T1), initial recovery (T2), and after 17 wks of sustained recovery (T3). Severe life events at T1 predicted greater attrition, a more favorable postrecovery symptom course, and a lower likelihood of recurrence over 3 yrs. Life stress at T2 was not predictive of outcomes. Finally, undesirable life events at T3 tended to predict a worse symptom course and a higher likelihood of recurrence, particularly for individuals on medication. The findings are discussed in terms of (a) different processes influenced by life stress over time and (b) limitations of existing longitudinal research for studying the effects of life stress over prolonged intervals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
72.
The influence of annealing temperature and time on solute carbon levels was investigated in four ultralow-carbon (ULC) bake-hardenable steels; two Ti-V ULC steels with different V/C levels and two Ti-Nb ULC steels with different Nb/C levels. Internal-friction and scanning transmission electron microscopy (STEM) techniques were used to understand the precipitation/dissolution behavior in the various steels. An effect of annealing time on the carbon Snoek-peak height was observed in both Ti-V steels and in the Ti-Nb steel having a lower Nb/C ratio. Despite differences between these steels resulting from their composition (and, thus, carbide solubility) differences, after cold rolling and annealing at different temperatures, the maximum Snoek-peak height was achieved after annealing for shorter times in each instance, on the order of 1 minute. The highly stabilized Ti-Nb ULC steel with a higher Nb/C ratio did not show the effect because of the absence of solute carbon. For the Ti-V steels, most of the precipitates examined using STEM contained both Ti and V. The energy-dispersive X-ray (EDX) analysis indicated that both the Ti-V steels annealed at 845 °C for 1 minute have greater Ti/V ratios compared to their corresponding Ti-V steels in the as-received (hot-rolled) condition. This behavior is consistent with dissolution of carbides causing the carbon in solution to increase, as indicated by a greater carbon Snoek-peak height for both Ti-V steels in the annealed condition. The reduction in Snoek-peak height at longer annealing times is believed to be associated with segregation to lower-energy defect sites.  相似文献   
73.
Slicing Software for Model Construction   总被引:8,自引:0,他引:8  
Applying finite-state verification techniques (e.g., model checking) to software requires that program source code be translated to a finite-state transition system that safely models program behavior. Automatically checking such a transition system for a correctness property is typically very costly, thus it is necessary to reduce the size of the transition system as much as possible. In fact, it is often the case that much of a program's source code is irrelevant for verifying a given correctness property.In this paper, we apply program slicing techniques to remove automatically such irrelevant code and thus reduce the size of the corresponding transition system models. We give a simple extension of the classical slicing definition, and prove its safety with respect to model checking of linear temporal logic (LTL) formulae. We discuss how this slicing strategy fits into a general methodology for deriving effective software models using abstraction-based program specialization.  相似文献   
74.
Most current control strategies for storm water treatment utilize fixed or filter-bed media with specific gravity (ρs) greater than 1.0. In contrast to Part I, Part II focuses on such higher density (ρs > 1.0) manganese-oxide-coated media that can be used in combined unit operations and processes for in-situ treatment of storm water. Methods were developed to coat manganese oxides onto sand and cementitious media for storm water treatment. With respect to manganese, coatings of ramsdellite produced a point of zero charge (PZC) of 5.2, while mixtures of birnessite and cryptomelane produced a PZC of 2.6 Manganese oxide increased the specific surface area (SSA) of sand and cementitious media. Manganese-oxide-coated sand (MOCS) produced a larger SSA (2.48-m2∕g), as compared with birnessite-coated media (BCM) (1.51 m2∕g), while the two have a similar surface charge (PZC = 6.4). Manganese-oxide-coated cementitious media (MOCM) produced a significantly larger SSA (19.49 m2∕g), as compared with coated sand, and SEM analyses indicated the surface contained manganese oxide and calcite of thickness 10–30 μm. Based on the results, coated cementitious media provided surface characteristics that can significantly enhance filtration and adsorption of heavy metal in storm water, in comparison to sand.  相似文献   
75.
Drawing from recent developments in social cognition, cognitive psychology, and behavioral decision theory, we analyzed when and how the act of measuring beliefs, attitudes, intentions, and behaviors affects observed correlations among them. Belief, attitude, or intention can be created by measurement if the measured constructs do not already exist in long-term memory. The responses thus created can have directive effects on answers to other questions that follow in the survey. But even when counterparts to the beliefs, attitudes, and intentions measured already exist in memory, the structure of the survey researcher's questionnaire can affect observed correlations among them. The respondent may use retrieved answers to earlier survey questions as inputs to response generation to later questions. We present a simple theory predicting that an earlier response will be used as a basis for another, subsequent response if the former is accessible and if it is perceived to be more diagnostic than other accessible inputs. We outline the factors that determine both the perceived diagnosticity of a potential input, the likelihood that it will be retrieved, and the likelihood that some alternative (and potentially more diagnostic) inputs will be retrieved. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
76.
This paper presents the rationale for the creation of the Microelectronics and Computer Research Corporation (MCC), to be a cooperative research organization funded by a number of U.S. computer and electronics companies.

Factors inhibiting investment in fundamental research by individual companies today are presented and analyzed, and the benefits of the consortium approach for cooperatively performing basic research and early exploratory development work are described.

The present research activities of MCC in the areas of Advanced Computer Architectures, Computer Aided Design, Software Technology, and Packaging and Interconnect technology are presented. This is followed by a discussion of future directions for research in the field of computer science.  相似文献   

77.
It is beyond doubt that high technology has elevated the standards of living of mankind. The modern technology created and developed to a great extent by Western or developed societies is now in great demand in Eastern and developing societies who are trying to leap-frog towards advancement. But unfortunately, in the transfer of technology, both the giver and the receiver seem to make many mistakes. A technology transferred without considering the ethnic variables in the societies and differences in the climates, has found to cause problems to the acquirer. Due to the basic human factor differences such as sizes of people, physical environment, physical capacities and organizational and cultural differences, a technology which is unadapted has found to be inappropriate, harmful, hazardous and unsuccessful. In the areas of health, working conditions, production and finance, undesirable effects have resulted through haphazard technology transfer, For a successful transfer, it is therefore stressed that technology has to be adapted or modified taking into consideration the technological, anthropological and socio-economic factors of the acquiring population.  相似文献   
78.
An outline is given of the information services used in the National Computing Centre. An update is provided of a previous paper describing the local area network implemented in 1981. Three IT landmarks are highlighted, these include the introduction of word processing, the local area network and a digital PABX. The implications and subsequent developments are described. The facilities available on the local area network are discussed. The use of three electronic mail services are also considered, along with the use of facsimile.  相似文献   
79.
It is argued that classical measures of computer system performance, for example mean response time, are inadequate in the context of fault-tolerant system design. Alternative, perception-based measures are proposed and theorems established describing their properties. Focus is directed upon the homogeneous M/M/m system in which total processor power is constrained by budget and processors are subject to failure and repair. A numerical technique for extracting both classical and perception-based measures from the associated two-dimensional Markov process is offered, along with bounds on time and space required for its execution. It is seen that the perception-based approach to system design can call for twice as many processors as the classical approach.  相似文献   
80.
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