Forcing and Generic Models

1997 ◽  
pp. 137-215
Author(s):  
Thomas Jech
Keyword(s):  
Generic Models

Finitely generic models of TUH, for certain model companionable theories T

1985 ◽  
Vol 50 (3) ◽  
pp. 604-610
Author(s):  
Francoise Point
Keyword(s):  
Discriminator Variety ◽  
Generic Models ◽  
Elementary Class ◽  
Ordered Groups ◽  
Existentially Closed ◽  
Closed Element ◽  
Starting Point ◽  
Joint Embedding ◽  
Joint Embedding Property ◽  
Generic Elements

The starting point of this work was Saracino and Wood's description of the finitely generic abelian ordered groups [S-W].We generalize the result of Saracino and Wood to a class ∑UH of subdirect products of substructures of elements of a class ∑, which has some relationships with the discriminator variety V(∑t) generated by ∑. More precisely, let ∑ be an elementary class of L-algebras with theory T. Burris and Werner have shown that if ∑ has a model companion then the existentially closed models in the discriminator variety V(∑t) form an elementary class which they have axiomatized. In general it is not the case that the existentially closed elements of ∑UH form an elementary class. For instance, take for ∑ the class ∑0 of linearly ordered abelian groups (see [G-P]).We determine the finitely generic elements of ∑UH via the three following conditions on T:(1) There is an open L-formula which says in any element of ∑UH that the complement of equalizers do not overlap.(2) There is an existentially closed element of ∑UH which is an L-reduct of an element of V(∑t) and whose L-extensions respect the relationships between the complements of the equalizers.(3) For any models A, B of T, there exists a model C of TUH such that A and B embed in C.(Condition (3) is weaker then “T has the joint embedding property”. It is satisfied for example if every model of T has a one-element substructure. Condition (3) implies that ∑UH has the joint embedding property and therefore that the class of finitely generic elements of ∑UH is complete.)

Generators, Generic Models and Methodology

1987 ◽  
Vol 38 (8) ◽  
pp. 765
Author(s):  
John G. Crookes
Keyword(s):  
Generic Models

scholarly journals Novel generic models for differentiating stem cells reveal oscillatory mechanisms

2021 ◽  
Vol 18 (183) ◽  
Author(s):  
Saeed Farjami ◽  
Karen Camargo Sosa ◽  
Jonathan H. P. Dawes ◽  
Robert N. Kelsh ◽  
Andrea Rocco
Keyword(s):  
Cell Fate ◽  
Regulatory Networks ◽  
Oscillatory Process ◽  
Oscillatory Regime ◽  
Epigenetic Landscape ◽  
Generic Models ◽  
Gene Regulatory ◽  
Oscillatory Mechanisms ◽  
Gradual Variation ◽  
Standard Framework

Understanding cell fate selection remains a central challenge in developmental biology. We present a class of simple yet biologically motivated mathematical models for cell differentiation that generically generate oscillations and hence suggest alternatives to the standard framework based on Waddington’s epigenetic landscape. The models allow us to suggest two generic dynamical scenarios that describe the differentiation process. In the first scenario, gradual variation of a single control parameter is responsible for both entering and exiting the oscillatory regime. In the second scenario, two control parameters vary: one responsible for entering, and the other for exiting the oscillatory regime. We analyse the standard repressilator and four variants of it and show the dynamical behaviours associated with each scenario. We present a thorough analysis of the associated bifurcations and argue that gene regulatory networks with these repressilator-like characteristics are promising candidates to describe cell fate selection through an oscillatory process.

scholarly journals The Context-Dependency of the Experience of Auditory Succession and Prospects for Embodying Philosophical Models of Temporal Experience

2015 ◽  
Vol 9 (3-4) ◽  
pp. 213
Author(s):  
Maria Kon
Keyword(s):  
Music Cognition ◽  
Context Dependency ◽  
General Notion ◽  
Philosophical Work ◽  
Temporal Experience ◽  
Generic Models ◽  
Research Programs ◽  
Bodily Movement ◽  
Musical Perception ◽  
Musical Cognition

Recent philosophical work on temporal experience offers generic models that are often assumed to apply to all sensory modalities.  We show that the models serve as broad frameworks in which different aspects of cognitive science can be slotted and, thus, are beneficial to furthering research programs in embodied music cognition.  Here we discuss a particular feature of temporal experience that plays a key role in such philosophical work: a distinction between the experience of succession and the mere succession of experiences.  We question the presupposition that there is such an evident, clear distinction and suggest that, instead, it is context-dependent.  After suggesting a way to modify the philosophical models of temporal experience to accommodate this context-dependency, we illustrate that these models can fruitfully incorporate research programs in embodied musical cognition.  To do so we supplement a philosophical model with Godøy’s recent work that links bodily movement with musical perception.  The Godøy-informed model is shown to facilitate novel hypotheses, refine our general notion of context-dependency and point towards possible extensions.

scholarly journals Syntactic approach to constructions of generic models

2007 ◽  
Vol 46 (2) ◽  
pp. 134-146 ◽  
Author(s):  
S. V. Sudoplatov
Keyword(s):  
Generic Models ◽  
Syntactic Approach

Biomass models for three species with different growth forms and geographic distribution in the Brazilian Atlantic forest

2021 ◽  
pp. 1-13
Author(s):  
Heitor Felippe Uller ◽  
Laio Zimermann Oliveira ◽  
Aline Renata Klitzke ◽  
Joberto Veloso de Freitas ◽  
Alexander Christian Vibrans
Keyword(s):  
Atlantic Forest ◽  
Geographic Distribution ◽  
Morphological Features ◽  
Brazilian Atlantic Forest ◽  
Growth Forms ◽  
Individual Level ◽  
Generic Models ◽  
The Individual ◽  
Species Specific ◽  
Individual Trees

Allometric models embedding independent variables such as diameter at breast height (d) and total height (h) are useful tools to predict the biomass of individual trees. Models for tropical forests are often constructed based on datasets composed of species with different morphological features and architectural models. It is reasonable to expect, however, that species-specific models may reduce uncertainties in biomass predictions, especially for palms, tree ferns, and trees with peculiar morphological features, such as stilt roots and hollow trunks. In this sense, three species with wide geographical distribution in the Brazilian Atlantic Forest were sampled, namely Euterpe edulis Mart., Cyathea delgadii Sternb., and Cecropia glaziovii Snethl., with the aim to (i) quantify their aboveground biomass (AGB), (ii) evaluate the AGB distribution in different plant compartments, (iii) fit species-specific models for predicting AGB at the individual level, and (iv) assess the performance of specific and generic models available in the literature to predict the AGB of individuals of these species. The compartment stem represented, on average, ∼74% of the total AGB of E. edulis individuals; in turn, the caudex compartment of C. delgadii represented, on average, ∼87% of the total AGB, while the trunk compartment of C. glaziovii represented, on average, ∼74%. Among the fitted models, the power model [Formula: see text] showed the best performance for E. edulis and C. delgadii. In turn, the asymptotic logistic model [Formula: see text], where dc is the diameter above the upper stilt root, presented the best performance for C. glaziovii. The variable h appeared as the most important predictor of AGB of E. edulis and C. delgadii; in contrast, the stem and caudex mean basic specific gravities were not suitable predictors. The fitted species-specific models outperformed the specific and generic models selected from the literature. They may, therefore, contribute to the reduction of uncertainties in AGB estimates. In addition, the results support evidence that specific models may be necessary for species with different growth forms and (or) peculiar morphological features, especially those with great abundance and wide geographic distribution.

Generic Models of Electric Machine Applications in Hybrid Electric Vehicles Power Train Simulations

2013 ◽  
pp. 95-150
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Rotational Speed ◽  
Electric Machines ◽  
Simulation Studies ◽  
Permanent Magnet Motors ◽  
Power Train ◽  
Field Weakening ◽  
Generic Models ◽  
Hybrid Power

Chapter 4 presents an approach to obtain the power simulation model of electric machines that would be practically useful in hybrid power train simulation studies. The induction motor (AC) and the permanent magnet motor’s (PM) mathematical dynamic models are based on the necessary and fundamental knowledge conveyed in the previous chapter. These generic models are here adapted to the hybrid power train requirements, while the mechanical characteristics of the vehicle’s driving system are relegated to the background. The vector field oriented control of induction and permanent magnet motors is applied in the conducted mathematical modeling. The influence of the controlled voltage frequency is discussed as well. In the case of permanent magnet motors, the adjusted method of magnetic field weakening is very important during pulse modulation (PWM) control. The chapter presents the model of synchronous permanent motor magnetic field weakening. The basic simulation studies’ results dedicated especially to the above-mentioned electric motors are included. One of the targets of these simulations is the determination of these electric machines’ static characteristics (motor’s map) as the function: output mechanical torque versus the motors’ shaft rotational speed. This feature is indicated as the map of electric machines connected with its efficiency in a four quarterly operation (4Q), which means the operation of the motor/generator mode in two directions of the shaft rotational speed, which appears very useful in practice.

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