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关键词： Asymptotic variance   bias   skewness   studentization   mean square error   log-linear models  

摘要： The asymptotic cumulants of the minimum phi-divergence estimators of the parameters in a model for categorical data are obtained up to the fourth order with the higher-order asymptotic variance under possible model misspecification. The corresponding asymptotic cumulants up to the third order for the studentized minimum phi-divergence estimator are also derived. These asymptotic cumulants, when a model is misspecified, depend on the form of the phi-divergence. Numerical illustrations with simulations are given for typical cases of the phi-divergence, where the maximum likelihood estimator does not necessarily give best results. Real data examples are shown using log-linear models for contingency tables.

摘要： BackgroundLanguage impairments are a core feature of schizophrenia. Category fluency is severely impacted, even as early as the first-episode of psychosis (FEP). It remains unclear which brain regions in the early course of schizophrenia are dysfunctional during category fluency. Therefore, we investigated differences in fMRI bold activity during a category fluency task in FEP, with particular attention to left temporo-parietal junction (TPJ) and inferior frontal gyrus (IFG), areas critical to verbal fluency. Our hypothesis was that left TPJ would show overactivity in FEP due to functional dysconnectivity with IFG, thought to modulate TPJ ***-seven FEP and 25 matched healthy controls (HC) completed an overt category fluency task (animal naming) from the MATRICS Consensus Cognitive Battery (MCCB), and a covert category fluency task while BOLD fMRI was acquired. The fMRI task had a total of 10 blocks (30s duration) with two alternating conditions: category and rest. At the beginning of the category condition, a category name (birds, breeds of dogs, fruits and vegetables, fish, flowers and trees) was displayed on the screen, and individuals were instructed to think of items within that category. At the beginning of the rest condition, individuals were instructed to silently repeat the word “rest” to themselves. To isolate the activity related to category exemplar generation, the rest condition and the category condition fMRI data were contrasted using SPM12. An uncorrected cluster-defining primary threshold of p<.001 was used at the voxel level, and an FWE correction was used at the cluster level to correct for multiple *** (47.3±12.1) were significantly less fluent compared to HC (55.8±11.3) in the overt MCCB category fluency task (p =.017). In the fMRI covert fluency task, several regions were activated during the category condition (FWE p<.05), primarily including regions in the language network (IFG and TPJ). The left TPJ acti

关键词： Global odds ratio   linear-by-linear association model   median measure   ordered stereotype model   uneven spacing  

摘要： Deciding on the best statistical method to apply when the response variable is ordinal is essential because the way the categories are ordered in the data is relevant as it could change the results of the analysis. Although the models for continuous variables have similarities to those for ordinal variables, this paper presents the advantages of the use of the ordering information on the outcomes with methods developed for modeling ordinal data such as the ordered stereotype model. The novelty of this article lies in showing the dangers of assigning equally spaced scores to ordered response categories in statistical analysis, which are illustrated with a simulation study and a case study. We propose a new way to use the score parameters, which incorporates the fitted spacing dictated by the data. Additionally, this article uses score parameter estimates in the ordered stereotype model to propose a new measure to calculate continuous medians in the raw data: the adjusted c-median. It benefits the general audience who can easily understand the median as a summary statistic. Supplementary materials for this article are available online.

关键词： Derived categories   Singularity categories   Ring spectra   Koszul duality   BGG correspondence  

摘要： We propose an analogue of the bounded derived category for an augmented ring spectrum, defined in terms of a notion of Noether normalization. In many cases we show this category is independent of the chosen normalization. Based on this, we define the singularity and cosingularity categories measuring the failure of regularity and coregularity and prove they are Koszul dual in the style of the BOG correspondence. Examples of interest include Koszul algebras and Ginzburg DG-algebras, C*(BG) for finite groups (or for compact Lie groups with orientable adjoint representation), cochains in rational homotopy theory and various examples from chromatic homotopy theory. (C) 2020 Elsevier Inc. All rights reserved.

关键词： Modular operad   Segal condition   Reedy category   Quillen model category  

摘要： We present a homotopy theory for a weak version of modular operads whose compositions and contractions are only defined up to homotopy. This homotopy theory takes the form of a Quillen model structure on the collection of simplicial presheaves for a certain category of undirected graphs. This new category of undirected graphs, denoted U, plays a similar role for modular operads that the dendroidal category ( )Omega plays for operads. We carefully study properties of U, including the existence of certain factorization systems. Related structures, such as cyclic operads and stable modular operads, can be similarly treated using categories derived from U. (C) 2020 Elsevier Inc. All rights reserved.

关键词： Categorification   Boson-fermion correspondence   Clifford algebra   Heisenberg algebra  

摘要： We construct a Heisenberg counterpart of a Clifford categorification. It is a modification of Khovanov's Heisenberg categorification. We relate generators of the Heisenberg category with a complex of generators of the Clifford category. Certain vertex operators associated to the Clifford algebra are lifted to endofunctors of the Fock space categorification. (C) 2020 Elsevier Inc. All rights reserved.

关键词： Biowaste   Food waste   Municipal waste   Methane   Anaerobic digestion   Characterization   Orientation   Pulping   Leaching   Conditioning   Pretreatment  

摘要： Biowaste material is a good candidate for the production of energy in urban territories. The presence of undesirable or constituents mixed with the biowaste collected by municipalities makes it difficult to recycle organic matter of sufficient quality for agricultural uses. Methane production is particularly attractive for energy recovery notably because this energy vector can be distributed using the grid already in place for natural gas in many cities. Depending on the origin and biochemical composition of biowaste, methane can be produced using thermochemical (gasification then syngas methanation) or biological processes (anaerobic digestion). The objective of this work was to characterize the ability of biowaste to be used as a feedstock for anaerobic digestion. Based on considerations such as the quantities produced and the availability, four categories of biowaste produced in the city of Lyon were identified as potential key resources: Garden biowaste (GBW), restauration biowaste (RBW), household biowaste (HBW) and supermarkets biowaste (SMBW). Representative samples were taken from the sites of production and analyzed for parameters including biomethane potential (BMP). Each sample was then fractioned by leaching and the distribution of the BMP between the particulate fraction and the readily soluble fraction was assessed. GBW organic matter exhibited high hemicellulose content (over 81% of VS) and a low BMP which was very poorly distributed into its soluble fraction (2 ***(TS)(-1)) RBW, HBW and SMBW showed a much higher BMP with a strong distribution in the soluble fraction (100 ***(TS)(-1)). Plastic materials were found to account for up to 40% of the mass of SMBW sample. Altogether, GBW was identified as non-favorable for anaerobic digestion and recommended rather for thermochemical conversion. HBW, RBW and SMBW revealed adapted to anaerobic. Pulping was shown to be applicable in order to convert the 3 biowaste materials into a pumpable slurry with hig

关键词： auditory categorization   auditory cortex   frontal cortex   ferret   long-term memory   top-down modulation  

摘要： Categorical perception is a fundamental cognitive function enabling animals to flexibly assign sounds into behaviorally relevant categories. This study investigates the nature of acoustic category representations, their emergence in an ascending series of ferret auditory and frontal cortical fields, and the dynamics of this representation during passive listening to task-relevant stimuli and during active retrieval from memory while engaging in learned categorization tasks. Ferrets were trained on two auditory Go-NoGo categorization tasks to discriminate two non-compact sound categories (composed of tones or amplitude-modulated noise). Neuronal responses became progressively more categorical in higher cortical fields, especially during task performance. The dynamics of the categorical responses exhibited a cascading top-down modulation pattern that began earliest in the frontal cortex and subsequently flowed downstream to the secondary auditory cortex, followed by the primary auditory cortex. In a subpopulation of neurons, categorical responses persisted even during the passive listening condition, demonstrating memory for task categories and their enhanced categorical boundaries.

关键词： Distance-association model   clustering   latent class analysis   mixture distribution   EM algorithm   BIC  

摘要： Distance association models constitute a useful tool for the analysis and graphical representation of cross-classified data in which distances between points inversely describe the association between two categorical variables. When the number of cells is large and the data counts result in sparse tables, the combination of clustering and representation reduces the number of parameters to be estimated and facilitates interpretation. In this article, a latent block distance-association model is proposed to apply block clustering to the outcomes of two categorical variables while the cluster centers are represented in a low dimensional space in terms of a distance-association model. This model is particularly useful for contingency tables in which both the rows and the columns are characterized as profiles of sets of response variables. The parameters are estimated under a Poisson sampling scheme using a generalized EM algorithm. The performance of the model is tested in a Monte Carlo experiment, and an empirical data set is analyzed to illustrate the model.