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Rigorous Test (rigorous + test)

Distribution by Scientific Domains

Psychology	33%
Engineering	33%

Selected Abstracts

Evaluating MT3DMS for Heat Transport Simulation of Closed Geothermal Systems

GROUND WATER, Issue 5 2010
Jozsef Hecht-Méndez
Owing to the mathematical similarities between heat and mass transport, the multi-species transport model MT3DMS should be able to simulate heat transport if the effects of buoyancy and changes in viscosity are small. Although in several studies solute models have been successfully applied to simulate heat transport, these studies failed to provide any rigorous test of this approach. In the current study, we carefully evaluate simulations of a single borehole ground source heat pump (GSHP) system in three scenarios: a pure conduction situation, an intermediate case, and a convection-dominated case. Two evaluation approaches are employed: first, MT3DMS heat transport results are compared with analytical solutions. Second, simulations by MT3DMS, which is finite difference, are compared with those by the finite element code FEFLOW and the finite difference code SEAWAT. Both FEFLOW and SEAWAT are designed to simulate heat flow. For each comparison, the computed results are examined based on residual errors. MT3DMS and the analytical solutions compare satisfactorily. MT3DMS and SEAWAT results show very good agreement for all cases. MT3DMS and FEFLOW two-dimensional (2D) and three-dimensional (3D) results show good to very good agreement, except that in 3D there is somewhat deteriorated agreement close to the heat source where the difference in numerical methods is thought to influence the solution. The results suggest that MT3DMS can be successfully applied to simulate GSHP systems, and likely other systems with similar temperature ranges and gradients in saturated porous media. [source]

Beyond ethnic match: Effects of client,therapist cognitive match in problem perception, coping orientation, and therapy goals on treatment outcomes

JOURNAL OF COMMUNITY PSYCHOLOGY, Issue 5 2005
Nolan Zane
This study examined the outcome effects of cognitive match between Asian and White outpatient clients and their therapists. Many clinicians believe that one hindrance to the treatment of ethnic minority clients is that therapists and clients may not share common assumptions and attitudes about therapy and about the problems that are presented in treatment. The study investigated client,therapist similarity in their perceptions of the presenting problem, coping orientation, and expectations about treatment goals. This study constituted a more rigorous test of the cognitive match hypotheses in that it was prospective in nature, used separate and independent sources for the cognitive predictors, employed multiple outcome measures, and focused on specific attitudes and perceptions that are quite salient and relevant to treatment. Cognitive match on treatment goals was predictive of session impact. Moreover, cognitive matches in avoidant coping orientation and in perceived distress associated with interpersonal problems were predictive of certain treatment outcomes. The findings may help explain why clients matched on ethnicity with their therapists tend to stay longer in treatment and do better in psychotherapy. © 2005 Wiley Periodicals, Inc. J Comm Psychol 33: 569,585, 2005. [source]

The parameterization and validation of generalized born models using the pairwise descreening approximation

JOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 14 2004
Julien Michel
Abstract Generalized Born Surface Area (GBSA) models for water using the Pairwise Descreening Approximation (PDA) have been parameterized by two different methods. The first method, similar to that used in previously reported parameterizations, optimizes all parameters against the experimental free energies of hydration of organic molecules. The second method optimizes the PDA parameters to compensate only for systematic errors of the PDA. The best models are compared to Poisson,Boltzmann calculations and applied to the computation of potentials of mean force (PMFs) for the association of various molecules. PMFs present a more rigorous test of the ability of a solvation model to correctly reproduce the screening of intermolecular interactions by the solvent, than its accuracy at predicting free energies of hydration of small molecules. Models derived with the first method are sometimes shown to fail to compute accurate potentials of mean force because of large errors in the computation of Born radii, while no such difficulties are observed with the second method. Furthermore, accurate computation of the Born radii appears to be more important than good agreement with experimental free energies of solvation. We discuss the source of errors in the potentials of mean force and suggest means to reduce them. Our findings suggest that Generalized Born models that use the Pairwise Descreening Approximation and that are derived solely by unconstrained optimization of parameters against free energies of hydration should be applied to the modeling of intermolecular interactions with caution. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1760,1770, 2004 [source]

Elevation gradients of species-density: historical and prospective views

GLOBAL ECOLOGY, Issue 1 2001
MARK. V. Lomolino
Abstract Studies of elevation clines in diversity and composition of ecological communities date back to the origins of biogeography. A modern resurgence of interests in these elevational clines is likely to contribute important insights for developing a more general theory of species diversity. In order to gain a more comprehensive understanding of geographical clines in diversity, the research programme for montane biogeography should include statistically rigorous tests of apparent patterns, comparisons of patterns among regions and taxonomic or ecological groups of species, and analyses of clines in environmental variables concurrent with biogeographical surveys. The conceptual framework for this research programme should be based on the assumption that elevational gradients in species diversity result from a combination of ecological and evolutionary processes, rather than the presumed independent effects of one overriding force. Given that montane ecosystems are hot spots of biological diversity, an expanded and integrated programme for biogeographic surveys in montane regions should provide valuable insights for conservation biologists. [source]

CHALLENGES IN MODELING HYDROLOGIC AND WATER QUALITY PROCESSES IN RIPARIAN ZONES,

JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 1 2006
Shreeram Inamdar
ABSTRACT: This paper presents key challenges in modeling water quality processes of riparian ecosystems: How can the spatial and temporal extent of water and solute mixing in the riparian zone be modeled? What level of model complexity is justified? How can processes at the riparian scale be quantified? How can the impact of riparian ecosystems be determined at the watershed scale? Flexible models need to be introduced that can simulate varying levels of hillslope-riparian mixing dictated by topography, upland and riparian depths, and moisture conditions. Model simulations need to account for storm event peak flow conditions when upland solute loadings may either bypass or overwhelm the riparian zone. Model complexity should be dictated by the level of detail in measured data. Model algorithms need to be developed using new macro-scale and meso-scale experiments that capture process dynamics at the hillslope or landscape scales. Monte Carlo simulations should be an integral part of model simulations and rigorous tests that go beyond simple time series, and point-output comparisons need to be introduced. The impact of riparian zones on watershed-scale water quality can be assessed by performing simulations for representative hillsloperiparian scenarios. [source]

Industrial and Organisation Research on Self-Regulation: From Constructs to Applications

APPLIED PSYCHOLOGY, Issue 2 2005
Jeffrey B. Vancouver
L'autorégulation rencontre actuellement du succès en psychologie industrielle et organisationnelle. Les travaux théoriques et empiriques englobent des processus allant de l'entrée dans l'organisation à la sortie et à la réembauche. Les interventions et les concepts clés de l'autorégulation dans le monde du travail sont recensés en insistant sur la validité interne et de construction. Quelques concepts comme l'efficacité personnelle et l'implication ont bénéficié d'un grand intérêt de la part des psychométriciens et semblent constituer des cibles de premier ordre lors des interventions. Néanmoins, ces concepts restent entachés d'hypothèses dont la validité n'est pas garantie. D'autres concepts, en particulier la rétroaction et la divergence, souffrent de significations sensiblement différentes dans la littérature sur l'autorégulation, ce qui nuit à la compréhension et à la communication entre les universitaires et les praticiens. On a lancé des interventions relevant des principes de l'autorégulation; celles-ei ont ensuite étéévaluées avec sérieux: il est apparu qu'elles avaient un impact sur un ensemble de variables pertinentes du point de vue organisationnel comme l'amélioration des performances et la réduction de l'absentéisme. Malheureusement, les interventions sont rarement étudiées de façon détaúllée et systématique, ce qui ne permet pas de tirer des conclusions sur les aspects de l'intervention qui sont pertinents du point de vue de la causalité. La discussion insiste sur les lacunes dans la connaissance et l'appréhension des processus de l'autorégulation dans les contextes organisationnels, ainsi que sur la façon dont la discipline pourrait tenter de combler ces lacunes. The self-regulation perspective is currently well received in the industrial and organisational psychology literature. Theoretical and empirical work span processes ranging from organisation entry to exit and reentry. Key self-regulation constructs and interventions in work contexts are reviewed with a focus on construct and internal validity. Some constructs, such as self-efficacy and goal commitment, have received substantial psychometric attention and seem important targets for interventions. Nonetheless, potentially unwarranted assumptions remain regarding these constructs. Other constructs, particularly feedback and discrepancy, have acquired substantially different meanings within the self-regulation literature that inhibit understanding and communication among scholars and practitioners. Interventions based on self-regulatory principles have been developed, and rigorous tests of these interventions have been conducted. These interventions were found to influence a range of organisationally relevant outcomes such as increasing performance and reducing absenteeism. Unfortunately, studies of comprehensive interventions are rare and often lacked controls, making it difficult to draw conclusions regarding what aspects of the interventions are causally relevant. Discussion focuses on the gaps in the field's knowledge and understanding regarding self-regulatory processes in organisational settings and how the field might attempt to fill those gaps. [source]