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61.
Comparative optimism has been studied extensively in adults and is a significant component of social- cognitive models about health. In contrast, little is known about comparative optimism in children or about the wider social- cognitive processes that underpin their health-related behavior. This study investigated comparative optimism for health- and nonhealth-related topics in 101 children 8 or 9 years of age, the youngest ages that have been investigated so far. Children were shown to be unrealistically optimistic for health and nonhealth events. The implications of these findings for understanding comparative optimism in children are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
62.
Jawed I. Siddiqi Ian C. Morrey Chris R. Roast Mehmet B. Ozcan 《Annals of Software Engineering》1997,3(1):131-155
Assuring a high quality requirements specification document involves both an early validation process and an increased level of participation. An approach and its supporting environment which combines the benefits of a formal system specification and its subsequent execution via a rapid prototype is reported. The environment assists in the construction, clarification, validation and visualisation of a formal specification. An illustrative case study demonstrates the consequences of assertions about system properties at this early stage of software development. Our approach involves the pragmatic combination of technical benefits of formal systems engineering based techniques with the context‐sensitive notions of increased participation of both developer and user stakeholders to move us closer towards a quality requirements specification document. 相似文献
63.
A review of the various models of New Product Development (NPD) process shows that although different approaches have been proposed, they are in fact all variants on a linear theme: some may include feedback loops, but they all essentially advocate that certain steps precede, or are preceded by, others. An inevitable consequence on the Internet/World Wide Web (WWW or Web) is that such models are no longer applicable. Based on the lessons learned from the development of a new financial service offered via the Internet, we show how such assumptions of linearity need no longer be a constraint. In addition, innovativeness is not related to firm size. But the fact that the Web allows for the real-time development of new financial services based on on-going feedback from potential and current customers raises a new set of managerial issues that have to be tackled. The objective of this paper is to use the context of the recent launch of an innovative financial service product via the Web to explore the managerial changes that are starting to affect the banking industry. 相似文献
64.
Christopher Jefferson Angela Miguel Ian Miguel S. Armagan Tarim 《Computers & Operations Research》2006
Peg Solitaire is a well known puzzle, which can prove difficult despite its simple rules. Pegs are arranged on a board such that at least one ‘hole’ remains. By making draughts/checkers-like moves, pegs are gradually removed until no further moves are possible or some goal configuration is achieved. This paper considers the English variant, consisting of a board in a cross shape with 33 holes. Modelling Peg Solitaire via constraint or integer programming techniques presents a considerable challenge and is examined in detail. The merits of the resulting models are discussed and they are compared empirically. The sequential nature of the puzzle naturally conforms to a planning problem, hence we also present an experimental comparison with several leading AI planning systems. Other variants of the puzzle, such as ‘Fool's Solitaire’ and ‘Long-hop’ Solitaire are also considered. 相似文献
65.
Although some studies suggest positive effects of treatment for sexual offenders, most studies have been hampered by the unknown influence of selective attrition (e.g., volunteers and drop-outs). In the 1980s, the Correctional Service of Canada began to require weekly community treatment sessions for all sex offenders released in the Pacific Region. This policy change provided a unique opportunity for comparing an unselected cohort of treated sex offenders (n = 403) to an untreated cohort (n = 321) released in earlier years. After an average 12-year follow-up period, no differences were observed in the rates of sexual (21.1% vs 21.8%), violent (42.9% vs. 44.5%) or general (any) recidivism (56.6% vs 60.4%) for treated and untreated groups, respectively. The outcome remained comparable after controlling for length of follow- up, year of release, age, and seven static risk factors coded from official criminal history records. Retrospective ratings of the treatment quality also showed no relationship to observed recidivism rates. The static risk factors coded in the current study accounted for considerable variance in recidivism and could easily be used to improve statistical controls in future evaluations. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
66.
Velocity Distribution in the Roughness Layer of Rough-Bed Flows 总被引:1,自引:0,他引:1
Vladimir Nikora Katinka Koll Ian McEwan Stephen McLean Andreas Dittrich 《Canadian Metallurgical Quarterly》2004,130(10):1036-1042
Several models for the vertical distribution of the double-averaged (in time and in the plane parallel to the mean bed) longitudinal velocity in the flow region between roughness troughs and roughness tops are suggested. We found that the same model for velocity distribution may be applicable to a range of flow conditions and roughness types, which share some common features. The suggested models for velocity distribution in the near-bed region are: (1) Constant velocity; (2) exponential velocity distribution; and (3) linear velocity distribution. The measured velocity distributions may be approximated by a single model or by a combination of models depending on roughness geometry and flow conditions. The validity of these models for velocity distribution is supported by laboratory data. 相似文献
67.
Phil Surman Ian Sexton Richard Bates Wing Kai Lee Kam Chaun Yow 《Journal of the Society for Information Display》2004,12(2):153-158
Abstract— Under the European Union funded Advanced Three‐dimensional Television System Technologies (ATTEST) project, De Montfort University (DMU) is developing a 3D display system targeted specifically at domestic television applications. This system uses a modified transmissive LCD panel together with novel backlighting and optics to project multiple viewing regions, or exit pupils, into the viewing space. These exit pupils are located in space using a head tracker. The display accommodates multiple viewers simultaneously and imposes no physical constraints, such as special eyewear. Viewers may move freely over a “typical” room‐sized area. The design of the backlighting facilitates many other display regimes beyond the “standard” 3DTV mode in which each viewer sees the same image pair. 相似文献
68.
Joshua Elliott Meredith Franklin Ian Foster Todd Munson Margaret Loudermilk 《Computational Economics》2012,39(3):219-241
While computable general equilibrium (CGE) models are a well-established tool in economic analyses, it is often difficult
to disentangle the effects of policies of interest from that of the assumptions made regarding the underlying calibration
data and model parameters. To characterize the behavior of a CGE model of carbon output with respect to two of these assumptions,
we perform a large-scale Monte Carlo experiment to examine its sensitivity to base year calibration data and elasticity of
substitution parameters in the absence of a policy change. By examining a variety of output variables at different levels
of economic and geographic aggregation, we assess how these forms of uncertainty impact the conclusions that can be drawn
from the model simulations. We find greater sensitivity to uncertainty in the elasticity of substitution parameters than to
uncertainty in the base-year data as the projection period increases. While many model simulations were conducted to generate
large output samples, we find that few are required to capture the mean model response of the variables tested. However, characterizing
standard errors and empirical probability distribution functions is not possible without a large number of simulations. 相似文献
69.
Ian Foster 《International journal of parallel programming》1989,18(3):181-203
An asynchronous garbage collector for a message-passing multiprocessor (multicomputer) is described. This combines Weighted Reference Counting (WRC) interprocessor collection and tracing intraprocessor collection to permit individual processors to reclaim local storage independently. A novel feature is the integration of Weighted Reference Counting collection and the communication algorithms required to support a global address space in a single assignment language. This significantly reduces communication overhead and space requirements attributable to garbage collection. In addition, techniques are described that avoid the creation of cyclic structures that cannot be reclaimed using WRC. Experimental studies performed in a concurrent logic programming system that incorporates the collector confirm its efficiency and the benefits of integrating garbage collector and language implementation. 相似文献
70.
The use of porous polymer monoliths functionalized with silver nanoparticles is introduced in this work for high-sensitivity surface-enhanced Raman scattering (SERS) detection. Preparation of the SERS detection elements is a simple process comprising the synthesis of a discrete polymer monolith section within a silica capillary, followed by physically trapping silver nanoparticle aggregates within the monolith matrix. A SERS detection limit of 220 fmol for Rhodamine 6G is demonstrated, with excellent signal stability over a 24 h period. The capability of the SERS-active monolith for label-free detection of biomolecules was demonstrated by measurements of bradykinin and cytochrome c. The SERS-active monoliths can be readily integrated into miniaturized micrototal-analysis systems for online and label-free detection for a variety of biosensing, bioanalytical, and biomedical applications. 相似文献