• Rasch
  • Linear logistic models with relaxed assumptions (LLRA) are a flexible tool for item-based measurement of change or multidimensional Rasch models. (springer.com)
  • Testing the Rasch model. (springer.com)
  • A Rasch model for partial credit scoring. (springer.com)
  • The Rasch model, named after Georg Rasch, is a psychometric model for analyzing categorical data, such as answers to questions on a reading assessment or questionnaire responses, as a function of the trade-off between (a) the respondent's abilities, attitudes, or personality traits and (b) the item difficulty. (wikipedia.org)
  • The mathematical theory underlying Rasch models is a special case of item response theory and, more generally, a special case of a generalized linear model. (wikipedia.org)
  • However, there are important differences in the interpretation of the model parameters and its philosophical implications that separate proponents of the Rasch model from the item response modeling tradition. (wikipedia.org)
  • A central aspect of this divide relates to the role of specific objectivity, a defining property of the Rasch model according to Georg Rasch, as a requirement for successful measurement. (wikipedia.org)
  • By requiring measures to remain the same (invariant) across different tests measuring the same thing, Rasch models make it possible to test the hypothesis that the particular challenges posed in a curriculum and on a test coherently represent the infinite population of all possible challenges in that domain. (wikipedia.org)
  • A Rasch model is therefore a model in the sense of an ideal or standard that provides a heuristic fiction serving as a useful organizing principle even when it is never actually observed in practice. (wikipedia.org)
  • The perspective or paradigm underpinning the Rasch model is distinct from the perspective underpinning statistical modelling. (wikipedia.org)
  • The rationale for this perspective is that the Rasch model embodies requirements which must be met in order to obtain measurement, in the sense that measurement is generally understood in the physical sciences. (wikipedia.org)
  • This key requirement is embodied within the formal structure of the Rasch model. (wikipedia.org)
  • Consequently, the Rasch model is not altered to suit data. (wikipedia.org)
  • The logit is also central to the probabilistic Rasch model for measurement, which has applications in psychological and educational assessment, among other areas. (wikipedia.org)
  • illustrate
  • In this paper we introduce and illustrate new functionality from the R package eRm for fitting, comparing and plotting of LLRA models for dichotomous and polytomous responses with any number of time points, treatment groups and categorical covariates. (springer.com)
  • To illustrate this phenomenon, we analyze a real data set using a Lagrange multiplier test for the specification of the model. (springer.com)
  • We illustrate that the method is particularly suited to problems in covariate set uncertainty and random effects models. (uni-muenchen.de)
  • function
  • The two common way of designing reverse logistics network are the Mixed Integer Linear Programing (MILP) and Mixed Integer Non-Linear Programing (MINLP) methods, where the objective function, decision variables and constraint have to be defined This model is a two-level location problem with three type of facilities, integrated forward and reverse flow of goods. (wikipedia.org)
  • Objective function: minimizing linear cost function including fix and variable costs Decision variables: location of manufacturer and distribution centeramount of production demand quantity of returned used products Constraints: satisfaction of the demand opening of facilities This model take into account just reverse flow of goods. (wikipedia.org)
  • Robust optimization: This method is calibrating the model in that way to minimize the deviation of the values of the objective function at each scenario. (wikipedia.org)
  • The GLM generalizes linear regression by allowing the linear model to be related to the response variable via a link function and by allowing the magnitude of the variance of each measurement to be a function of its predicted value. (wikipedia.org)
  • Imagine, for example, a model that predicts the likelihood of a given person going to the beach as a function of temperature. (wikipedia.org)
  • Generalized linear models cover all these situations by allowing for response variables that have arbitrary distributions (rather than simply normal distributions), and for an arbitrary function of the response variable (the link function) to vary linearly with the predicted values (rather than assuming that the response itself must vary linearly). (wikipedia.org)
  • assumes
  • Classical test theory assumes a state model because it is applied by determining item parameters for a sample of examinees determined to be in each category. (wikipedia.org)
  • The classification groups will need to be more or less arbitrarily defined along the continuum, such as the use of a cutscore to demarcate masters and nonmasters, but the specification of item parameters assumes a trait model. (wikipedia.org)
  • prediction model
  • The key question is how best to assess and quantify the improvement in risk prediction offered by new biomarkers or more basically how to assess the performance of a risk prediction model. (diva-portal.org)
  • As an example, a prediction model might predict that 10 degree temperature decrease would lead to 1,000 fewer people visiting the beach is unlikely to generalize well over both small beaches (e.g. those where the expected attendance was 50 at a particular temperature) and large beaches (e.g. those where the expected attendance was 10,000 at a low temperature). (wikipedia.org)
  • The problem with this kind of prediction model would imply a temperature drop of 10 degrees would lead to 1,000 fewer people visiting the beach, a beach whose expected attendance was 50 at a higher temperature would now be predicted to have the impossible attendance value of −950. (wikipedia.org)
  • simulation
  • City logistics long-term planning: simulation of shopping mobility and goods restocking and related support systems Agostino Nuzzolo, Antonio Comi and Luca Rosati 8. (bookdepository.com)
  • classification
  • The combination of a multilevel model with random person effects and one with random item effects leads to a cross-classification multilevel model, which can be of interest for IRT applications. (ed.gov)
  • distribution
  • The beta distribution is a simple and flexible model in which responses are naturally confined to the finite interval (0,1). (umsystem.edu)
  • A new derivation of the logistic distribution. (springer.com)
  • The huge expansion in international trade during the last 50 years (facilitated and propelled by the invention of the standardized container as a medium of transport) has led to overcrowding of port facilities world-wide and growing pains in logistic systems handling the customs examination, storage and distribution of containers. (igi-global.com)
  • In this model the products are gathered from the consumers and transferred back to the producers, hence the direction of the flow in the distribution supply chain is reversed and the model is expanded with the recovery center. (wikipedia.org)
  • responses
  • In contrast, the BBL model naturally has bounded responses and inhomogeneous variance. (umsystem.edu)
  • In IRT models, responses are explained on the basis of person and item effects. (ed.gov)
  • probabilities
  • That is, it is a model that is used to predict the probabilities of the different possible outcomes of a categorically distributed dependent variable, given a set of independent variables (which may be real-valued, binary-valued, categorical-valued, etc. (wikipedia.org)
  • likelihood
  • The asymptotic normality of maximum likelihood estimators (MLEs) is obtained even though the support of this non-regular regression model depends on unknown parameters. (umsystem.edu)
  • They proposed an iteratively reweighted least squares method for maximum likelihood estimation of the model parameters. (wikipedia.org)
  • efficient
  • As city logistics aims at creating efficient and environmental-friendly urban freight transport systems, these chapters deal with challenging urban freight transport problems from various point of views of the usage of ITS (Intelligent Transport Systems), multi-agent modelling, public-private partnerships, and the disaster consideration. (bookdepository.com)
  • advantages
  • We show the BBL model has advantages over the 4PL model. (umsystem.edu)
  • The model highlights the advantages that shippers may enjoy in routing their containers from the seaports to their final hinterland destinations via one or several interports. (igi-global.com)
  • 1987
  • Criminologist Lynch (1987), using "domain-specific" models, demonstrates that occupation-related activities generally have a stronger impact on the risk of victimization at work than sociodemographic characteristics. (wikipedia.org)
  • Binary
  • For the binary case, a common approach is to apply Platt scaling, which learns a logistic regression model on the scores. (wikipedia.org)
  • This allows the choice of K alternatives to be modeled as a set of K-1 independent binary choices, in which one alternative is chosen as a "pivot" and the other K-1 compared against it, one at a time. (wikipedia.org)
  • application
  • Comparing consumer preferences for color and nutritional quality in maize: Application of a semi-double-bound logistic model on urban consumers in Kenya ," Food Policy , Elsevier, vol. 33(4), pages 362-370, August. (repec.org)
  • Application of exact route optimization for the evaluation of a city logistics truck ban scheme Ali Gul Qureshi, Eiichi Taniguchi, Russell G. Thompson and Joel S.E. Teo 3. (bookdepository.com)
  • Model of debris collection operation after disasters and its application in urban area Andie Pramudita and Eiichi Taniguchi 9. (bookdepository.com)
  • collaboration
  • We also propose that these models could be useful for thinking in the different interactions happening in the economic world, as for instance for the competition and the collaboration between corporations. (igi-global.com)
  • Collaboration in urban logistics: motivations and barriers Lindawati, Johan van Schagen, Mark Goh and Robert de Souza 12. (bookdepository.com)
  • methods
  • Discrimination, calibration, and added predictive value have been recently suggested to be used while comparing the predictive performances of the predictive models' with and without novel biomarkers.Objectives: Lack of user-friendly statistical software has restricted implementation of novel model assessment methods while examining novel biomarkers. (diva-portal.org)
  • analysis
  • The overparameterized analysis of variance Model. (springer.com)
  • Equivalent models in covariance structure analysis. (springer.com)
  • The main objective is to maximize profit by determining the optimal number of facilities in order to: collection point be close to the consumers returning process be simple collection period be appropriate Sensitivity analysis: Through sensitivity analysis it can be tested how the output of the model will be changed if the decision variables such as the returned amount, number of disassembly and cost are varying. (wikipedia.org)
  • construct
  • Furthermore, these models could be considered as the basic ingredients to construct more complex interactions in the ecological and economic networks. (igi-global.com)
  • items
  • In a similar way, the effects of the items can be studied as random parameters, yielding multilevel models with a within-item part and a between-item part. (ed.gov)
  • It means that the used items are gathered from consumers, transported back to plants and after remanufacturing get into the logistics network of new products. (wikipedia.org)
  • In most contexts, the parameters of the model characterize the proficiency of the respondents and the difficulty of the items as locations on a continuous latent variable. (wikipedia.org)
  • change
  • An implication is that there may well be many ways to change the specification of a given LLTM and achieve the same improvement in model fit. (springer.com)
  • A reasonable model might predict, for example, that a change in 10 degrees makes a person two times more or less likely to go to the beach. (wikipedia.org)
  • authors
  • Mathematically, the authors identify the "interport model" as an extension of the conventional transshipment problem in a hub-and-spokes configuration with the interport treated as a novel kind of hub. (igi-global.com)