Goodness of Fit

The selective vapor phase epitaxy (SVPE) kinetics of a Si1−xGex heterostructure is complex. To date, operational kinetics schemes are not available and reactant interactions are not very well understood. This study is a phenomenological investigation of epitaxial film growth rate (GR) and composition. An empirical model is developed specifically to address the kinetics of industrial SVPE processes performed at a pressure above 1Torr. The response function investigated in this study is very similar to the one applied in the field of heterogeneous catalysis. The relevance of a power rate law (PRL) to Si 1−xGex SVPE is assessed with the goodness of fit as well as with a consistency check of the fitting parameters with the chemistry of the process. Despite the lack of a reaction scheme supporting the PRL, trends consistent with the known chemistry of growth kinetics are evidenced, thus confirming the soundness of the method. Partial reaction orders are identified for HCl, SiH2Cl2, GeH4 ...

We compared a physiological model of 82Rb kinetics in the myocardium with two reduced-order models to determine their usefulness in assessing physiological parameters from dynamic PET data. A three-compartment model of 82Rb in the myocardium was used to simulate kinetic PET ROI data. Simulations were generated for eight different blood-flow rates reflecting the physiological range of interest. Two reduced-order models commonly used with myocardial PET studies were fit to the simulated data, and parameters of the reduced-order models were compared with the physiological parameters. Then all three models were fit to the simulated data with noise added. Monte Carlo simulations were used to evaluate and compare the diagnostic utility of the reduced-order models. A description length criterion was used to assess goodness of fit for each model. Finally, fits to simulated data were compared with fits to actual dynamic PET data. Fits of the reduced-order models to the three-compartment mode...

Several studies have established the predictive power of the yield curve in terms of real economic activity. In this paper we use data for a variety of E.U. countries: both EMU (Germany, France, Italy, Portugal and Spain) and non-EMU members (Norway, Sweden and the U.K.). The data used range from 1991:Q1 to 2009:Q3. For each country, we extract the long

The duality between measures of economic and technical efficiency has been extensively studied in the productive efficiency analysis. This duality ensures a meaningful interpretation of technical efficiency as economic efficiency evaluated at the most favorable shadow prices. This paper concentrates on economic efficiency as short run profit efficiency. We first argue that a modified version of Varian?s goodness-of-fit measure provides

Sorption isotherms were determined for salted alligator's meat at four different temperatures (10°C, 15°C, 25°C and 35°C), using a standard gravimetric method. The goodness of fit of five sorption models to experimental data was determined. Five models, namely the GAB, the BET, the Halsey, the Henderson and the Hailwood and Horrobin, were evaluated to determine the best fit for the experimental data. The GAB was the best fitted model for the data of salted alligator's meat with an average error less than 10% for temperature of 10°C and less than 5% for the others temperatures. The coefficients of determination (r2) were 0.99 for all temperatures considered. The monolayer values decreased as temperature increased. The other four models were not appropriated to fit the data because of the high error values, although the r2 were also similar to the GAB model. The net isosteric heat of sorption was estimated from equilibrium sorption data, using the Clausis–Clapeyron equation. Isosteric heats of sorption were found to increase with increasing temperature and could be well adjusted by an exponential relationship.

Objective: Calibration with LC-MS data may be accomplished with different combinations of curve fit, weighting, and origin treatment. Agilent's Mass Hunter Quantitative Analysis software contains a Curve Fit Assistant, which allows comparison of over 100 different calibration options. Curve fit choices include linear, quadratic, power, logarithmic, second order logarithmic, and average of response factors. Weighting choices include equal, inverse x

The Community of Inquiry model provides a framework for recognizing and evaluating interpersonal behaviors in online educational settings. One of its three components, teaching presence, describes behaviors that are under the auspices of the online instructor. By examining behaviors through the theoretical lens provided by teaching presence, and by measuring them with the Teaching Presence Scale (TPS), it may be possible to better understand the most effectively online instruction practices. The purpose of the study was to confirm the factor composition of TPS in an online professional development course and to determine the relationship between teaching presence and student satisfaction. Participants (n = 718) were in-service educators enrolled in online professional development. Confirmatory factor analysis results provided strongest support for a three-factor TPA model using 17 of the 28 original TPS items and evidence of a strong relationship between TPS and student satisfaction...

A family-centred occupational therapy assessment and treatment package for children with attention deficit hyperactivity disorder (ADHD) was evaluated. The package involves a multidimensional evaluation and a multifaceted intervention, which are aimed at achieving a goodness-of-fit between the child, the task demands and the environment in which the child carries out the task. The package lasts for 3 months, with 12

SigrafW is Windows-compatible software developed using the Microsoft® Visual Basic Studio program that uses the simplified Hill equation for fitting kinetic data from allosteric and Michaelian enzymes. SigrafW uses a modified Fibonacci search to calculate maximal velocity (V), the Hill coefficient (n), and the enzyme-substrate apparent dissociation constant (K). The estimation of V, K, and the sum of the squares of residuals is performed using a Wilkinson nonlinear regression at any Hill coefficient (n). In contrast to many currently available kinetic analysis programs, SigrafW shows several advantages for the determination of kinetic parameters of both hyperbolic and nonhyperbolic saturation curves. No initial estimates of the kinetic parameters are required, a measure of the goodness-of-the-fit for each calculation performed is provided, the nonlinear regression used for calculations eliminates the statistical bias inherent in linear transformations, and the software can be used for enzyme kinetic simulations either for educational or research purposes.Persons interested in receiving a free copy of the software should contact Dr. F. A. Leone.

The psychological phenomenon of mindfulness-a nonjudgmental attention to and awareness of one's present experience-has been linked to effective coping with a range of situational stressors such as the transition to college, romantic relationships, and cancer. However, the potential mediating role of problem-focused coping strategies in predicting these outcomes has not been sufficiently addressed. In the current study we rectified this void in the literature by testing several problem-focused mechanisms for mindfulness's relationship with situational stress coping in college undergraduates affected by the current COVID-19 pandemic. Using a correlational design, we tested whether: (1) dispositional mindfulness would predict less stress, less negative affect, and greater positive affect in the face of stressors manifested by the COVID-19 pandemic and (2) several problem-focused coping strategies would mediate the zero-order relationships between mindfulness and these criterion variables. We collected self-reports of all study variables from college students enrolled in the principal investigator's undergraduate psychology courses via an online questionnaire. Results supported the expected associations between mindfulness and each of the well-being variables and partially supported the mediational hypotheses, with two out of the proposed five problem-focused strategies serving as statistically significant mediators. These results suggest that in addition to the primarily cognition-based mechanisms examined in previous research, mindfulness may also confer resistance to negative emotional states through adaptive behavior-based coping strategies.