Flexible multibody impact simulations based on the isogeometric analysis approach

Usually detailed impact simulations are based on isoparametric finite element models. For the inclusion in multibody dynamics simulation, e.g., in the framework of the floating frame of reference, a previous model reduction is necessary. A precise representation of the geometry is essential for modeling the dynamics of the impact. However, isoparametric finite elements involve the discretization of the geometry. This work tests isogeometric analysis (IGA) models as an alternative approach in the context of impact simulations in flexible multibody systems. Therefore, the adaption of the flexible multibody system procedure to include IGA models is detailed. The use of nonuniform rational basis splines (NURBS) allows the exact representation of the geometry. The degrees of freedom of the flexible body are afterwards reduced to save computation time in the multibody simulation. To capture precise deformations and stresses in the area of contact as well as elastodynamic effects, a large number of global shape functions is required. As test examples, the impact of an elastic sphere on a rigid surface and the impact of a long elastic rod are simulated and compared to reference solutions.

Reasoning over Attack-incomplete AAFs in the Presence of Correlations

Attack-Incomplete Abstract Argumentation Frameworks (att- iAAFs) are a popular extension of AAFs where attacks are marked as uncertain when they are not unanimously per- ceived by different agents reasoning on the same arguments. We here extend att-iAAFs with the possibility of specifying correlations involving the uncertain attacks. This feature sup- ports a unified and more precise representation of the differ- ent scenarios for the argumentation, where, for instance, it can be stated that an attack α has to be considered only if an attack β is considered, or that α and β are alternative, and so on. In order to provide a user-friendly language for spec- ifying the correlations, we allow the argumentation analyst to express them in terms of a set of elementary dependen- cies, using common logical operators (namely, OR , NAND , CHOICE , ⇒). In this context, we focus on the problem of verifying extensions under the possible perspective, and study the sensitivity of its computational complexity to the forms of correlations expressed and the semantics of the extensions.

Tissue scale agent-based simulation of premalignant progressions in Barrett’s esophagus

Barrett’s esophagus (BE) is a benign condition of the distal esophagus that initiates a multistage pathway to esophageal adenocarcinoma (EAC). Short of frequent intrusive (and costly) surveillance, effective screening for neoplasia in BE populations is yet to be established since progressors are rare and virtually undetectable without routine biopsies, which often sample only a small portion of the BE tissue. As a result, reliable estimation of the true prevalence of dysplasia in a BE population and evidence-based optimization of screening for at-risk individuals is challenging. Data-driven microsimulations, i.e., model-generated instances of disease history in a predefined virtual population, have found utility in the EAC screening literature as low-overhead alternatives to real-world hypothesis testing of optimal interventions for dysplasia. Despite the successes, computational limitations, paucity of knowledge and data on Barrett’s dysplasia, and the complexities of disease progression as a multiscale multiphysics process have hindered the treatment of disease progression in BE as a spatial process. Agent-based modeling of nucleation and proliferation processes in dysplasia warrants exploration in this context as an approximation that operates at a trade-off between computational tractability and precise representation of the composition and physics of the substrate (tissue). In this study, we describe spatially resolved simulations of premalignant progression toward EAC in a coarse-grained model of Barrett’s tissue that resolves the metaplastic tissue at a length scale of 0.42 mm (~3300 crypts/mm2). The model is calibrated to reproduce historical high-grade dysplasia prevalence when model-generated patients are screened using the Seattle protocol.

Thermal Analysis of Heat Distribution in Busbars during Rated Current Flow in Low-Voltage Industrial Switchgear

The manuscript presents advanced coupled analysis: Maxwell 3D, Transient Thermal and Fluent CFD, at the time of a rated current occurring on the main busbars in the low-voltage switchgear. The simulations were procured in order to aid the design process of such enclosures. The analysis presented the rated current flow in the switchgear busbars, which allowed determining their temperature values. The main assumption of the simulation was measurements of temperature rise during rated current conditions. Simulating such conditions is a valuable asset in order to design better solutions for energy distribution gear. The simulation model was a precise representation of the actual prototype of the switchgear. Simulations results were validated by experimental research. The heat dissipation in busbars and switchgear housing through air convection was presented. The temperature distribution for the insulators in the rail bridge made of fireproof material was considered: halogen-free polyester. The results obtained during the simulation allowed for a detailed analysis of switchgear design and proper conclusions in practical and theoretical aspects. That helped in introducing structural changes in the prepared prototype of the switchgear at the design and construction stages. Deep analysis of the simulation results allowed for the development concerning the final prototype of the switchgear, which could be subjected to the full type tests. Additionally, short-circuit current simulations were procured and presented.

From the accounts of Philosophie rurale to the physiocratic Tableau: François Quesnay as a precursor of national accounting

Quesnay’s Tableau, as it appears in Philosophie rurale, is an understandable, robust and innovative construction despite detail errors. It provides a precise representation of the economic circuit. The accounts of chapter VII of Philosophie rurale are introduced and we explain how Quesnay’s Tableau comes from these accounts. The transposition of the accounts of chapter VII and of the Tableau into two input-output tables shows the balance of resources and uses. In order to shed light on the progress of exchanges along the year, the Tableau is also transposed into three double-entry accountings (proprietors, farmers and artisans).

Investigating the Global Monsoon by networks of extreme rainfall events

<p>A defining feature of the Earth’s climate is the annual variation of heavy precipitation and convergent wind circulation in the tropics and subtropics. This dominant mode of hemispherically distributed rainfall is often termed the 'global monsoon', comprising of regional monsoon systems on every continent. Monsoon regions are defined using<strong> </strong>annual precipitation differences and average seasonality rather than by the dynamical similarities of rainfall dynamics<strong>; </strong>they thus<strong> </strong>fail to (i) consider global patterns of extreme rainfall events (EREs), and (ii) take into account spatio-temporal similarities in timing and intensity of monsoonal circulation.</p><p>In this work, we investigate the dynamics of the Global Monsoon using the framework of complex networks derived from extreme rainfall events. In particular, we use time-delayed event synchronization applied to the GPCP rainfall dataset to first extract a network of global ERE teleconnections. We then identify regions with similar ERE patterns by applying<strong> </strong>on the global ERE network a Bayesian hierarchical clustering approach based on the stochastic block model.</p><p>Our work presents evidence to place different monsoon regions in a global context and therefore to describe them as a unified system with common underlying dynamics: Besides known teleconnections, our method captures various differently resolved representations of the global weather system. These range from a description containing two clusters separated by the hemispheric equator to a precise representation of distinguishable but connected monsoon regions. We argue that the global monsoon can be regarded as a hierarchical complex system into which regional monsoons are embedded in intermediate levels of the clustering hierarchy.</p>

The GA4GH Variation Representation Specification (VRS): a Computational Framework for the Precise Representation and Federated Identification of Molecular Variation

Maximizing the personal, public, research, and clinical value of genomic information will require that clinicians, researchers, and testing laboratories exchange genetic variation data reliably. Developed by a partnership among national information resource providers, public initiatives, and diagnostic testing laboratories under the auspices of the Global Alliance for Genomics and Health (GA4GH), the Variation Representation Specification (VRS, pronounced “verse”) is an extensible framework for the semantically precise and computable representation of variation that complements contemporary human-readable and flat file standards for variation representation. VRS objects are designed to be semantically precise representations of variation, and leverage this design to enable unique, federated identification of molecular variation. We describe the components of this framework, including the terminology and information model, schema, data sharing conventions, and a reference implementation, each of which is intended to be broadly useful and freely available for community use. The specification, documentation, examples, and community links are available at https://vrs.ga4gh.org/.

Anti-Geometry and NeutroGeometry Characterization of Non-Euclidean Data

Recently, a problem is addressed while dealing with fourth dimensional or non-Euclidean data sets. These are the data sets does not follow one of the postulates established by Euclid specially the parallel postulates. In this case, the precise representation of these data sets is major issues for knowledge processing tasks. Hence, the current paper tried to introduce some non-Euclidean geometry or Anti-Geometry methods and its examples for various applications.