Using parametric model order reduction for inverse analysis of large nonlinear cardiac simulations

Predictive high-fidelity finite element simulations of human cardiac mechanics commonly require a large number of structural degrees of freedom. Additionally, these models are often coupled with lumped-parameter models of hemodynamics. High computational demands, however, slow down model calibration and therefore limit the use of cardiac simulations in clinical practice. As cardiac models rely on several patient-specific parameters, just one solution corresponding to one specific parameter set does not at all meet clinical demands. Moreover, while solving the nonlinear problem, 90% of the computation time is spent solving linear systems of equations. We propose to reduce the structural dimension of a monolithically coupled structure-Windkessel system by projection onto a lower-dimensional subspace. We obtain a good approximation of the displacement field as well as of key scalar cardiac outputs even with very few reduced degrees of freedom, while achieving considerable speedups. For subspace generation, we use proper orthogonal decomposition of displacement snapshots. Following a brief comparison of subspace interpolation methods, we demonstrate how projection-based model order reduction can be easily integrated into a gradient-based optimization. We demonstrate the performance of our method in a real-world multivariate inverse analysis scenario. Using the presented projection-based model order reduction approach can significantly speed up model personalization and could be used for many-query tasks in a clinical setting

Improvement of modal scaling factors using mass additive technique

A general investigation into the improvement of modal scaling factors of an experimental modal model using additive technique is discussed. Data base required by the proposed method consists of an experimental modal model (a set of complex eigenvalues and eigenvectors) of the original structure and a corresponding set of complex eigenvalues of the mass-added structure. Three analytical methods,i.e., first order and second order perturbation methods, and local eigenvalue modification technique, are proposed to predict the improved modal scaling factors. Difficulties encountered in scaling closely spaced modes are discussed. Methods to compute the necessary rotational modal vectors at the mass additive points are also proposed to increase the accuracy of the analytical prediction

A new method to real-normalize measured complex modes

A time domain subspace iteration technique is presented to compute a set of normal modes from the measured complex modes. By using the proposed method, a large number of physical coordinates are reduced to a smaller number of model or principal coordinates. Subspace free decay time responses are computed using properly scaled complex modal vectors. Companion matrix for the general case of nonproportional damping is then derived in the selected vector subspace. Subspace normal modes are obtained through eigenvalue solution of the (M sub N) sup -1 (K sub N) matrix and transformed back to the physical coordinates to get a set of normal modes. A numerical example is presented to demonstrate the outlined theory

A Benchmark to Understand the Role of Knowledge Graphs on Large Language Model's Accuracy for Question Answering on Enterprise SQL Databases

Enterprise applications of Large Language Models (LLMs) hold promise for question answering on enterprise SQL databases. However, the extent to which LLMs can accurately respond to enterprise questions in such databases remains unclear, given the absence of suitable Text-to-SQL benchmarks tailored to enterprise settings. Additionally, the potential of Knowledge Graphs (KGs) to enhance LLM-based question answering by providing business context is not well understood. This study aims to evaluate the accuracy of LLM-powered question answering systems in the context of enterprise questions and SQL databases, while also exploring the role of knowledge graphs in improving accuracy. To achieve this, we introduce a benchmark comprising an enterprise SQL schema in the insurance domain, a range of enterprise queries encompassing reporting to metrics, and a contextual layer incorporating an ontology and mappings that define a knowledge graph. Our primary finding reveals that question answering using GPT-4, with zero-shot prompts directly on SQL databases, achieves an accuracy of 16%. Notably, this accuracy increases to 54% when questions are posed over a Knowledge Graph representation of the enterprise SQL database. Therefore, investing in Knowledge Graph provides higher accuracy for LLM powered question answering systems.Comment: 34 page

Advances in Amorphous Oxide Semiconductor Devices, Materials, and Processes for Customizable Scalable Manufacturing of Thin-Film Electronics

Electronic circuits comprised of thin-film transistors (TFTs) are essential to nearly every modern display technology. For decades, the TFT industry relied on amorphous silicon, but increasing performance demands required semiconductors with superior electron transport leading to the adoption of amorphous oxide semiconductors (AOS). The superior electron transport and ease of thin-film preparation of AOS has led to a growing interest in developing thin-film electronics for beyond-display technologies. These include monolithic 3D integration on Si complementary metal-oxide-semiconductor integrated circuits (ICs) – to continue Moore’s law, add new functionality, and improve performance – and flexible electronics for electronic skins, textiles, solar cells, and displays. In this thesis we facilitate the adoption of thin-film electronics for beyond-display technologies by: 1) developing uniform and conformal AOS deposition processes with record performance; 2) demonstrating expanded AOS capabilities by exploring new device architectures; and 3) developing a new additive manufacturing technique for customizable scalable manufacturing. First, we meet the performance and thermal budget requirements of AOS for beyond-display applications by using atomic-layer deposition (ALD) – a conformal, uniform, and precise vapor-phase deposition technique – and aggressively optimizing the process conditions. We discovered that improved electrical performance correlated with an increase in film density, which can be achieved by increasing deposition temperature, by post-deposition annealing, and by using plasma enhanced-ALD (PE-ALD). Second, we made innovations in device design to expand the range of circuit applications for AOS TFTs by exploiting the benefit of their wide-bandgap to fabricate high-voltage TFTs (HVTFTs). While the current handling capabilities of these HVTFTs cannot compete with conventional power electronics, the ability to deposit AOS materials directly on Si ICs may enable monolithic 3D integration of HVTFTs, adding new functionality as an HV interface to aggressively scaled low-voltage Si CMOS. Third, we show that ambient instabilities are caused by interactions between the surface of the AOS film and ambient molecules. We eliminate these instabilities by developing an ALD-based passivation layer. Fourth, we study the temporal and bias stress stability of our ALD AOS thin-film transistors and see excellent stability after the first month of aging and improved positive bias stress stability with passivation. Fifth, we investigate several materials to form a Schottky contact to ALD AOS films to enable future rectifier-based circuits and unipolar logic circuits. Finally, we develop an additive manufacturing approach for customizable manufacturing of AOS devices. Further improvement in device performance and reduction of channel length, enabled by the sub-µm precision of EHD, has the potential to yield fully customizable additive manufacturing of high-frequency circuits.PHDElectrical and Computer EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/169721/1/allemang_1.pd

Application of the Financial Industry Business Ontology (FIBO) for development of a financial organization ontology

The article considers an approach to a formalized description and meaning harmonization for financial terms and means of semantic modeling. Ontologies for the semantic models are described with the help of special languages developed for the Semantic Web. Results of FIBO application to solution of different tasks in the Russian financial sector are given

Instructional materials to support an integrated social studies theme on families for primary students in a multi-age classroom

The purpose of this project was to assemble a collection of instructional materials to be used in my primary multi-age classroom in Cedar Rapids, Iowa. The organizing objectives were taken from the district\u27s social studies theme for Families and the district\u27s objectives for integrated language arts. The goal of the project was to coordinate a group of quality materials and suggest response activities to support using an integrated curriculum approach, specifically a literature-based social studies theme

Dynamic similarity design method for an aero-engine dualrotor test rig

This paper presents a dynamic similarity design method to design a scale dynamic similarity model (DSM) for a dual-rotor test rig of an aero-engine. Such a test rig is usually used to investigate the major dynamic characteristics of the full-size model (FSM) and to reduce the testing cost and time for experiments on practical aero engine structures. Firstly, the dynamic equivalent model (DEM) of a dual-rotor system is modelled based on its FSM using parametric modelling, and the first 10 frequencies and mode shapes of the DEM are updated to agree with the FSM by modifying the geometrical shapes of the DEM. Then, the scaling laws for the relative parameters (such as geometry sizes of the rotors, stiffness of the supports, inherent properties) between the DEM and its scale DSM were derived from their equations of motion, and the scaling factors of the above-mentioned parameters are determined by the theory of dimensional analyses. After that, the corresponding parameters of the scale DSM of the dual-rotor test rig can be determined by using the scaling factors. In addition, the scale DSM is further updated by considering the coupling effect between the disks and shafts. Finally, critical speed and unbalance response analysis of the FSM and the updated scale DSM are performed to validate the proposed method

More Than Simply “Letting Go”: Stakeholder Perspectives on Parental Roles in Health Care Transition

The transfer from pediatric to adult health care for youth with special health care needs (YSHCN) is a vulnerable period. Parents play a pivotal role in the transition process, however, little is known about the specific ways they may support YSHCN in negotiating the transition to adult services. A qualitative supplementary secondary data analysis was conducted to explore stakeholders’ perceptions about parents’ roles in health care transition. Thematic analysis was used to analyze individual and focus group interviews. Four themes were identified: 1) Parents are crucial; 2) Changing roles; 3) Interdependence rather than independence; 4) One of many transitions. These themes may serve as the basis for planning future intervention studies directed at parents of YSHCN

Female fighters and the fates of rebellions: How mobilizing women influences conflict duration

We investigate the potential relationship between female combatants and conflict duration. We contend that recruiting female combatants extends war duration via its influence on state–rebel bargaining. The recruitment and deployment of female combatants contribute to divergent perspectives between the rebels and the incumbent regarding the rebel group’s capabilities and the depth of its resolve, which impedes successful bargaining and extends the duration of the conflict. Results from duration analyses using data on the estimated prevalence of female combatants in rebel groups active between 1964 and 2011 support our central hypothesis and suggest that the use of female fighters is associated with longer conflicts