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Heuristic Model (heuristic + model)
Selected AbstractsGrammatical Inference Techniques and Their Application in Ground InvestigationCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 1 2008Ian Morrey The data obtained from trial pits can be coded into a form that can be used as sample observations for input to a grammatical inference machine. A grammatical inference machine is a black box, which when presented with a sample of observations of some unknown source language, produces a grammar which is compatible with the sample. This article presents a heuristic model for a grammatical inference machine, which takes as data sentences and non-sentences identified as such, and is capable of inferring grammars in the class of context-free grammars expressed in Chomsky Normal Form. An algorithm and its corresponding software implementation have been developed based on this model. The software takes, as input, coded representations of ground investigation data, and produces as output a grammar which describes and classifies the geotechnical data observed in the area, and also promises the possibility of being able to predict the likely configuration of strata across the site. [source] Behavioral and Psychiatric Comorbidities in Pediatric Epilepsy: Toward an Integrative ModelEPILEPSIA, Issue 9 2007Joan K. Austin Summary:, It is well recognized that children with epilepsy are at heightened risk for developing behavior problems and psychiatric disorders. Studies identifying factors associated with child behavior were reviewed and findings were placed into two broad categories for review and critique: illness-related variables and psychosocial variables. Illness-related variables were seizure frequency and seizure control, type of epilepsy, age of onset, duration of illness, and antiepileptic drugs. Psychosocial variables were reviewed using a family stress framework: stressors, perceptions, adaptive resources, coping, and family adjustment. After the literature on each category is reviewed, an integrated heuristic model that includes key illness-related and psychosocial variables is presented. [source] Dispersion in non-ideal packed bedsAICHE JOURNAL, Issue 2 2010U. M. Scheven Abstract This work reanalyzes published time series dispersion traces (Han et al., AIChE J. 1985;31:277,288) from step input tracer passages recorded at different locations along the length of a packed bed filled with monodisperse solid spheres. The intrinsic dispersivity and sample dependent dispersion are separated by imposing a heuristic model where coarse grained axial advection velocities vary in a plane perpendicular to the flow but not along the direction of flow. The derived intrinsic dispersivity agrees with the predicted value (Scheven et al., Phys Rev Lett. 2007;99:054502-1,054502-4). It serves as a bench mark for different implementations of simulations coupling Stokes flow and diffusion in random geometries, and for experimental tests of injection and packing methods. Conceptually, a well defined and fittable effective dispersivity is introduced in an analytical framework describing dispersion data obtained in non-ideal packed beds, where elution profiles cannot be fitted to the solution of the one dimensional advection diffusion equation. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source] Coercion, Cooperation, and Control: Understanding the Policy Impact of Administrative Courts and the Ombudsman in the NetherlandsLAW & POLICY, Issue 1 2001Marc Hertogh This article examines the way in which administrative courts and the National Ombudsman in the Netherlands seek to control administrative action, and is aimed at developing a heuristic model that can also be useful in a wider context. Two styles of control will be introduced: "coercive" and "cooperative." An exploratory empirical study was conducted of two administrative agencies, investigating the implementation process of court and ombudsman decisions. This article argues that it is likely that the policy impact of the courts and the ombudsman is directly related to their style of control. More empirical research is needed to evaluate this hypothesis. [source] The Social and Private Worlds of Speech: Speech for Inter- and Intramental ActivityMODERN LANGUAGE JOURNAL, Issue 3 2007HEATHER J. SMITH During a study designed to examine the processes of learning English as an additional language as manifest in the interactive behaviour of small groups of bilingual school children playing specially designed board games, several instances of private speech were captured. Private speech is commonly described as speech addressed to the self for intramental purposes. Unlike many studies, this research was not specifically aimed at eliciting private speech. Indeed, the overtly social nature of game playing probably acted to limit the production of speech for intramental purposes. In effect, therefore, interest lies in the fact that private speech was produced within this context. The article presents an examination of the functions of the private speech produced and the consequences of such outward verbalisation within this interactive group activity. As a result, a heuristic model of the relationship between speech for social and private purposes is proposed. [source] The Interpretive Process of Agenda-Building: A Research Design for Public PolicyPOLITICS & POLICY, Issue 1 2002Michael A. Smith A heuristic model is offered to guide empirical case studies into public policy change in a stable, pluralistic system. Empirical information, filtered to the policymakers and the public through a system of preexisting values, lies at the heart of policy change. The model integrates several strands of thought on policy, including: Baumgartner and Jones's theory of punctuated equilibrium, based on changes on policy images held by the relevant policy actors and the general public; Schattschneider's mobilization of bias; Cobb, Ross, and Ross's three models of agenda-building; Ripley and Franklin's theory of subgovernments; and Lindblom's emphasis on the role of the social scientist in responsible policymaking. In order to contribute productively to the policy process, social scientists must develop ethical, productive ways of responding to the ways in which other policy actors will use, and possibly distort, their findings. [source] Living alone, lack of a confidant and psychological well-being of elderly women in Singapore: the mediating role of lonelinessASIA-PACIFIC PSYCHIATRY, Issue 1 2010Lena L. Lim Abstract Background: The "feminization of aging" and nuclearization of families calls for research to examine the mental health and well-being of elderly women living alone. This study examined a proposed heuristic model whereby the relationship between living alone and lack of a confidant and psychological well-being is mediated by feeling of loneliness. Methods: Path analysis was performed on data of 1,205 community-living older women aged 55 and above with psychological well-being assessed by depressive symptoms (15-items Geriatric Depression Scale) and SF-12 MCS (mental component summary scale of the 12-item Short-Form Health Survey) quality of life scores assessed at baseline and follow-up 1.5 years later. Results: Goodness-of-fit indices used for the model showed good fits. All of the path coefficients were meaningful in absolute magnitude and significant at P<0.001. Living alone was associated concurrently with lack of a confidant (r=0.11), both of which predicts loneliness (path co-efficient=0.09). Loneliness predicts more depressive symptoms (path coefficient=0.25) and SF-12 MCS (path coefficient=,0.28) at baseline, as well as at follow-up. Conclusion: The findings suggest that loneliness mediates the relationship between living alone, lack of a confidant, and psychological well-being. Living alone becomes detrimental when it leads to loneliness. Social programs directed at elderly women who are living alone should alleviate loneliness through satisfactory interpersonal relationships, and emotional and spiritual support. [source] Visible and invisible effects of hurricanes on forest ecosystems: an international reviewAUSTRAL ECOLOGY, Issue 4 2008A. E. LUGO Abstract Hurricanes have visible and invisible effects on forests. The visible effects are dramatic, noticeable over the short-term and relatively well documented in the literature. Invisible effects are less understood as they require well-focused research both in the short- and long-term time scales. This review of the literature on hurricane effects focuses on the Neotropics and the temperate zone of North America. The material is organized according to a heuristic model that distinguishes between immediate effects (0 to 3 years), immediate responses (0 to 20 years), trajectories of responses (0 to 100 years) and long-term legacies (>100 years). It is suggested that the ecological role of hurricanes involves six principal effects: 1. they change the ecological space available to organisms; 2. they set organisms in motion; 3. they increase the heterogeneity of the landscape and the variability in ecosystem processes; 4. they rejuvenate the landscape and its ecosystems and redirect succession; 5. they shape forest structure, influence their species composition and diversity and regulate their function; and 6. they induce evolutionary change through natural selection and ecological creativity through self-organization. A new approach to hurricane research will study hurricanes at the same scale at which they operate (i.e., across latitudes and longitudes and over disturbed and undisturbed landscapes). This research will require networks of observation platforms located along expected hurricane paths to facilitate forest structure and functioning observations across gradients of hurricane frequency and intensity. This research will also require use of remote sensing and automated wireless technology, hardened to survive hurricane-strength winds and floods to assure real time measurements of the characteristics of hurricanes and ecosystem responses. No progress will be forthcoming in the understanding of hurricane effects if we do not learn to quantify objectively the energy dissipation of hurricanes on the full grid of affected forests as the hurricane passes over a landscape. [source] | |||||||||||||