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Modeling Procedures (modeling + procedure)
Selected AbstractsModeling of microwave devices with space mapping and radial basis functionsINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 3 2008Slawomir Koziel Abstract We review recent developments in space mapping techniques for modeling of microwave devices. We present a surrogate modeling methodology that utilizes space mapping combined with radial basis function interpolation. The method has advantages both over the standard space mapping modeling methodology and the recently published space mapping modeling with variable weight coefficients. In particular, it provides accuracy comparable or better than the latter method and computational efficiency as good as the standard space mapping modeling procedure. A comparison between the space mapping modeling methodologies as well as application examples of optimization and statistical analysis of microwave structures is presented. Copyright © 2007 John Wiley & Sons, Ltd. [source] Generalized nonlinear FET/HEMT modelingINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 2 2004J. Johnson Abstract A modeling procedure which provides an accurate large-signal response for variation in bias, input power level, and fundamental frequency for FET/HEMT transistors is designed. A procedure for measuring the large-signal input response on an easily implemented system is presented. The technique is illustrated by designing a nonlinear PHEMT model, which includes an accurate large-signal input response and works with variations in the aforementioned input conditions. © 2004 Wiley Periodicals, Inc. Int J RF and Microwave CAE 14, 122,133, 2004. [source] Teaching cooperative play to typical children utilizing a behavior modeling approach: a systematic replicationBEHAVIORAL INTERVENTIONS, Issue 3 2002Erik Jahr This study investigated the acquisition of cooperative play in three typical children. The differential effectiveness of two different modeling conditions was compared, where in the first condition the children were trained to observe and imitate modeled cooperative play. In the second condition the children observed and described the modeled play prior to imitation. During training, modeled play episodes varied across play topics. The criterion for mastery in training was correct responding on first trial with new modeled play episodes. The results showed that the children became able to take turns in novel episodes of cooperative play and to show play variability only after including verbal description as part of the modeling procedure. Copyright © 2002 John Wiley & Sons, Ltd. [source] Dynamic Metabolic Modeling for a MAB BioprocessBIOTECHNOLOGY PROGRESS, Issue 1 2007Jianying Gao Production of monoclonal antibodies (MAb) for diagnostic or therapeutic applications has become an important task in the pharmaceutical industry. The efficiency of high-density reactor systems can be potentially increased by model-based design and control strategies. Therefore, a reliable kinetic model for cell metabolism is required. A systematic procedure based on metabolic modeling is used to model nutrient uptake and key product formation in a MAb bioprocess during both the growth and post-growth phases. The approach combines the key advantages of stoichiometric and kinetic models into a complete metabolic network while integrating the regulation and control of cellular activity. This modeling procedure can be easily applied to any cell line during both the cell growth and post-growth phases. Quadratic programming (QP) has been identified as a suitable method to solve the underdetermined constrained problem related to model parameter identification. The approach is illustrated for the case of murine hybridoma cells cultivated in stirred spinners. [source] A Stable and Efficient Numerical Algorithm for Unconfined Aquifer AnalysisGROUND WATER, Issue 4 2009Elizabeth Keating The nonlinearity of equations governing flow in unconfined aquifers poses challenges for numerical models, particularly in field-scale applications. Existing methods are often unstable, do not converge, or require extremely fine grids and small time steps. Standard modeling procedures such as automated model calibration and Monte Carlo uncertainty analysis typically require thousands of model runs. Stable and efficient model performance is essential to these analyses. We propose a new method that offers improvements in stability and efficiency and is relatively tolerant of coarse grids. It applies a strategy similar to that in the MODFLOW code to the solution of Richard's equation with a grid-dependent pressure/saturation relationship. The method imposes a contrast between horizontal and vertical permeability in gridblocks containing the water table, does not require "dry" cells to convert to inactive cells, and allows recharge to flow through relatively dry cells to the water table. We establish the accuracy of the method by comparison to an analytical solution for radial flow to a well in an unconfined aquifer with delayed yield. Using a suite of test problems, we demonstrate the efficiencies gained in speed and accuracy over two-phase simulations, and improved stability when compared to MODFLOW. The advantages for applications to transient unconfined aquifer analysis are clearly demonstrated by our examples. We also demonstrate applicability to mixed vadose zone/saturated zone applications, including transport, and find that the method shows great promise for these types of problem as well. [source] Tobacco sales in community pharmacies: remote decisions and demographic targetsJOURNAL OF COMMUNITY PSYCHOLOGY, Issue 1 2010Cory M. Morton This study applied multilevel modeling procedures with data from 678 community pharmacies and 382 residential census tracts in a Midwestern U.S. state to determine if two sets of variables: retail type (e.g., remotely owned, independently owned) and population demographics of the tracts in which outlets were located were associated with retail tobacco availability in community pharmacies. Data were derived from three archival sources: listings of all retailers in Iowa who obtained tobacco licenses in year 2003; all pharmacies registered with the Iowa Board of Pharmacy in 2003; and year 2000 census data. Refuting previous research, multilevel logistic regression results of this study demonstrate that population demographics, as well as retail type, significantly predict whether a community pharmacy sold tobacco. Pharmacies selling tobacco were more likely to be remotely owned outlets and located in areas with higher percentages of African American residents and higher median income. Implications for environmentally focused prevention interventions are discussed. © 2009 Wiley Periodicals, Inc. [source] Risk and resilience factors for posttraumatic stress symptomatology in Gulf War I veteransJOURNAL OF TRAUMATIC STRESS, Issue 1 2007Dawne S. Vogt What factors distinguish war-exposed veterans who experience posttraumatic stress symptomatology (PTSS) from those who do not? This study used structural equation modeling procedures to examine the complex interplay among predeployment, war-zone, and postdeployment factors as they relate to PTSS in a sample of Gulf War I veterans. A primary goal was to determine to what extent previously documented associations among Vietnam veterans would replicate in this more contemporary veteran cohort. Results supported a multivariate etiological perspective on PTSS, with war-zone factors accounting for the largest proportion of variance in PTSS. The majority of hypothesized associations held, suggesting that the mechanisms underlying PTSS may be similar across veteran cohorts. [source] Behavioral intermittence, Lévy patterns, and randomness in animal movementOIKOS, Issue 4 2009F. Bartumeus The recent debate on both the existence and the cause of fractal (Lévy) patterns in animal movement resonates with much deeper and richer problems in movement ecology: (1) establishing mechanistic links between animal behavior and statistical patterns of movement, and (2) understanding what is the role of randomness (stochasticity) in animal motion. Here, the idea of behavioral intermittence is shown to be crucial to establish mechanistic connections between the behavior of organisms and the statistical properties they generate when moving. Attention is drawn to the fact that some random walk modeling procedures can impair the identification of intermittent biological mechanisms which could govern major statistical properties of movement. This fact, together with some misconceptions and prejudices regarding the role of randomness in animal motion may explain why stochastic processes have been disregarded as a potential source of adaptation in animal movement. In the near future, the advances in biotelemetry together with a more explicit consideration of behavioral intermittence, and the development of novel random walk approaches, could help us to set up the bases for a landscape-level behavioral ecology. [source] Advances in the assessment of social competence: Findings from a preliminary investigation of a general outcome measure for social behaviorPSYCHOLOGY IN THE SCHOOLS, Issue 10 2008Kelli D. Cummings This study describes the initial validation of an innovative social--behavioral observational assessment tool that is designed to be used on a repeated basis to assess growth and development of social competence over time to: (a) identify the social functioning of all students, (b) assist in planning support for students at risk, and (c) evaluate the effectiveness of individual and system-wide interventions. Eighteen first-grade students were monitored over an 8-week period using the Initiation-Response Assessment (IRA) Code. The School Social Behavior Scales, a published teacher rating scale, was included as a criterion measure. Estimates of reliability and criterion-related validity were calculated for the IRA. The measure's sensitivity to growth over time and between-group variability were also assessed using hierarchical linear modeling procedures. Results indicate that scores on this measure are stable, and tap constructs similar to those assessed via teacher rating. © 2008 Wiley Periodicals, Inc. [source] Using video modeling to teach a domestic skill with an embedded social skill to adults with severe mental retardationBEHAVIORAL INTERVENTIONS, Issue 4 2004Melissa A. Bidwell We assessed whether three adults with severe mental retardation would acquire a domestic skill (making coffee) with an embedded social skill (serving coffee to and sitting down beside a peer) via video modeling procedures. Training was conducted in a classroom in the participants' day treatment setting. The intervention consisted of (i) watching a video of an adult with a developmental disability making coffee and initiating a social interaction with a peer; and (ii) receiving verbal praise for each step of the task that was performed correctly. All three participants mastered the task and demonstrated generalization across settings, stimuli, and people. Two participants performed with 100% accuracy on maintenance probes conducted 1 month following mastery, and one participant did so following booster training. Copyright © 2004 John Wiley & Sons, Ltd. [source] | ||||||||||||||||