General-purpose Software Research Articles

Comparative study of alternative equivalent frame approaches for the seismic assessment of masonry buildings in OpenSees

The equivalent frame (EF) idealisation of masonry structures is widely used in engineering structures. Despite its simplifications, reliable numerical models can be produced to calculate the seismic behaviour of unreinforced masonry (URM) buildings. Different EF modelling approaches have been implemented in commercial software specifically conceived for performing nonlinear analyses on URM buildings (such as 3Muri, adopted in this study). Furthermore, the adoption of such an approach is also possible in general-purpose structural analyses software packages, such as OpenSees, through an ad hoc implementation of analysts. The aim of this paper is to compare various EF modelling approaches by adopting alternative nonlinear beam-elements in OpenSees belonging to the distributed and the lumped plasticity. To this aim, the responses of some benchmark cases study available in the literature from the “URM nonlinear modelling-benchmark project” within the context of ReLUIS projects have been adopted to preliminary test the reliability of the alternative approaches considered. In particular, they consist of some single panels and a trilith, for which the results of various software are already available. In the paper, the results obtained with OpenSees have been more in-depth compared with 3Muri, which is assumed as representative of a larger set of EF models adopted in engineering-practice (having already verified in previous works that it provides a reasonable scatter with other software package options). Then, the analyses have been extended as well to a 3D building representative of the neighbourhood of ‘El Plantinar’ in Seville. An accurate comparison has been carried out in terms of generalised forces, drifts and damage at an element and at a global scale. The results have shown that the method proposed in this manuscript allows using OpenSees to calculate masonry structures with the EF approach with a good agreement to other engineering-practice oriented tools. Thus, this outcome may constitute, in future research, the basis for exploiting the potential and versatility of OpenSees in accounting for other tricky phenomena: the soil-foundation-structure interaction.

A general automatic method for mechanism optimization based on kinematic constraints and analytical Jacobian matrix

This paper proposes a general formulation intended for dimensional synthesis of kinematic chains based on the derivation of kinematic constraint equations in their matrix form and their subsequent assembly in a system of linear equations. In this way, the proposed formulation allows to calculate in a simple way the partial derivatives of the nodal coordinates of a mechanism with respect to the dimensional or input parameters. Here, a complete mathematical development of the equations is presented, obtaining a formulation suitable for its implementation in computer programs. The main utility of this type of calculation is its application to gradient calculation within optimal dimensional synthesis, being valid for different types of objectives (function, path, and motion generation), and for any planar mechanism composed of any number of elements connected by joints of revolution (R), prismatic (P) or the combination R + P. The developments described in this paper have been implemented in general-purpose GUI software to solve path generation problems.

Проблемы электродинамических усилий в индукционных нагревателях

Problems are considered related to electrodynamic forces in the powerful induction heaters of industrial and medium frequency. The methods are given for calculating the forces acting on the heated blanks, inductive coils, and magnetic cores. One of the methods is based on the calculation of the total ponderomotive force acting on the current-carrying conductors and ferromagnetic bodies. To implement these methods, general-purpose computer-aided engineering software based on the finite element method and suitable for building electrothermal models is required. Building of such models is a rather laborious process, and the calculations take a significant amount of time, which does not allow the required number of calculations to be carried out within a reasonable time. Other methods are based on the calculation of the partial derivative of reactive power by the required coordinate. Thus, the corresponding projection of the force on the given axis is calculated. In combination with the subject-oriented 2DELTA coupled electrothermal software, this approach allows to perform the required number of calculations with a suitable for practice of induction heating design accuracy and with significantly less time. Comparative analysis was carried out related to the safety of some types of industrial induction installations used for heating various metals. The technological processes of induction heating of copper, aluminum and some steel grades are considered. The main parameters influencing the negative impact of electrodynamic forces are shown. In particular, when analyzing the axial component of such a force, it was established that the force of friction of the heated ingots against the guides has a significant negative effect. In the case of heating of ferromagnetic ingots, the direction and magnitude of the electrodynamic force are also influenced by the thermal regime. The methods are proposed for solving the problems of ensuring electromechanical safety in the design and tests of induction installations.

APPLICATION OF THE SAP2000 COMPUTER PROGRAMME IN THE MODELLING OF AN UNDERGROUND QUARRY OF DIMENSION STONE

A numerical analysis of part of the underground quarry of dimension stone with designed maximum dimensions of the rooms was carried out with the SAP2000 software based on the finite element method. The main objective of the analysis was to examine the preliminary stability and the influence of excavation on the redistribution of stresses in the surrounding rock masses, thus confirming the applicability of the tributary area method. The analytical solution with the tributary area method showed satisfactory agreement with the numerical calculations, and the results of the analytical calculations were on the safe side. The obtained results confirmed the predicted behaviour of the rock mass, which confirms the use of SAP2000 as a general-purpose software for civil engineering in the field of mining. The highest concentrations of stresses and strains are found in the edge areas of the pillars, so their correct design is crucial. The safety factor of the point with the highest stresses was determined and a value of 2.21 was obtained, thus fulfilling the stability condition. As for the influence on the surrounding area, stress changes of less than 10% were determined based on the solutions for the vertical stresses at a distance of 20 m from the underground excavation.

Cglasso: An R Package for Conditional Graphical Lasso Inference with Censored and Missing Values

Sparse graphical models have revolutionized multivariate inference. With the advent of high-dimensional multivariate data in many applied fields, these methods are able to detect a much lower-dimensional structure, often represented via a sparse conditional independence graph. There have been numerous extensions of such methods in the past decade. Many practical applications have additional covariates or suffer from missing or censored data. Despite the development of these extensions of sparse inference methods for graphical models, there have been so far no implementations for, e.g., conditional graphical models. Here we present the general-purpose package cglasso for estimating sparse conditional Gaussian graphical models with potentially missing or censored data. The method employs an efficient expectation-maximization estimation of an ℓ₁ -penalized likelihood via a block-coordinate descent algorithm. The package has a user-friendly data manipulation interface. It estimates a solution path and includes various automatic selection algorithms for the two ℓ₁ tuning parameters, associated with the sparse precision matrix and sparse regression coefficients, respectively. The package pays particular attention to the visualization of the results, both by means of marginal tables and figures, and of the inferred conditional independence graphs. This package provides a unique and computational efficient implementation of a conditional Gaussian graphical model that is able to deal with the additional complications of missing and censored data. As such it constitutes an important contribution for empirical scientists wishing to detect sparse structures in high-dimensional data.

Operations and maintenance optimisation for a 100 MW wave energy farm in Ireland

Marine operations that are required for the development and service of offshore wave energy farms represent a significant proportion of the total project costs. These operations can be optimised through design and innovation to improve the LCOE of the project. This paper presents an analysis of marine operations in offshore renewable energy projects and ows the importance of early, detailed analysis and optimisation of these activities. The analysis uses general-purpose techno-economic analysis software developed by Wave Venture. The software provides an integrated engineering and financial simulation specifically designed for the needs of offshore renewable energy technology. A 100 MW wave energy farm, made up of 250 CorPower devices, off the west coast of Ireland is defined and analysed to demonstrate the capabilities of the techno-economic analysis incorporating a marine operations logistics model. The results demonstrate the strength of integrated logistics and finance software in the analysis and design of wave farms, and how these simulations can lead to significant improvements in the LCOE of offshore renewable energy projects.

Nonlinear Seismic Analysis of Perforated cold-formed steel shear wall with Upright Section

During the last few decades, cold-formed steel (CFS) is extensively used in mid- and low-rise housing due to the increasing demand of rapid constructions along with its various advantages in comparison with other structural material. Cold-formed steel framed shear walls (CFSFSW) are most common and primary lateral load resisting system. However, adopting it in the seismic zone is difficult, especially because many design components remain open. In this research an effort has been made to design the shear wall system with both unperforated and perforated upright sections using nonlinear static analysis method. In ABAQUS, a general-purpose finite element analysis software, three-dimensional models using shell elements are used to simulate a shear wall system. A comparative study regarding the lateral load capacities with respect to maximum allowable lateral deflection including different parameters like column sections, thickness and perforation arrangements are presented here. It was found that increasing thickness and including Chanel stiffeners improves the lateral strength of original upright section. The developed modelling protocol helps to estimate its lateral performance under earthquake with reasonable accuracy.

UncertainSCI: Uncertainty quantification for computational models in biomedicine and bioengineering

Background:Computational biomedical simulations frequently contain parameters that model physical features, material coefficients, and physiological effects, whose values are typically assumed known a priori. Understanding the effect of variability in those assumed values is currently a topic of great interest. A general-purpose software tool that quantifies how variation in these parameters affects model outputs is not broadly available in biomedicine. For this reason, we developed the ‘UncertainSCI’ uncertainty quantification software suite to facilitate analysis of uncertainty due to parametric variability. Methods:We developed and distributed a new open-source Python-based software tool, UncertainSCI, which employs advanced parameter sampling techniques to build polynomial chaos (PC) emulators that can be used to predict model outputs for general parameter values. Uncertainty of model outputs is studied by modeling parameters as random variables, and model output statistics and sensitivities are then easily computed from the emulator. Our approaches utilize modern, near-optimal techniques for sampling and PC construction based on weighted Fekete points constructed by subsampling from a suitably randomized candidate set. Results:Concentrating on two test cases—modeling bioelectric potentials in the heart and electric stimulation in the brain—we illustrate the use of UncertainSCI to estimate variability, statistics, and sensitivities associated with multiple parameters in these models. Conclusion:UncertainSCI is a powerful yet lightweight tool enabling sophisticated probing of parametric variability and uncertainty in biomedical simulations. Its non-intrusive pipeline allows users to leverage existing software libraries and suites to accurately ascertain parametric uncertainty in a variety of applications.

Elastic buckling of simply supported stiffened steel plates with circular opening

Steel plates are used as the main components of steel elements in many structures. Openings in steel elements may exist for maintenance or inspection purposes in addition to creating paths for different fixtures such as air conditioning, pipes, and facilities. The structural performance of plates with openings is different from that of solid plates when subjected to axial compressive load. Openings affect local buckling, lateral torsional buckling, and shear of plates. Adding stiffeners around openings is a common engineering practice to strengthen plates. However, different design codes and guides provide estimates of the flexural and shear capacity of beams with no clear formulas for the influence of such openings on axial buckling strength. In this study, a parametric study has been performed using general-purpose finite element software, ANSYS, in order to study the effect of using stiffeners around circular opening in simply supported axially loaded plates on the elastic buckling behavior. Different parameters were considered including the aspect ratio of the plate, opening diameter, opening position in both horizontal and vertical directions, and stiffener’s dimensions. The results of the extensive parametric study are used to propose an empirical design formula considering the different studied parameters.

Coupled hydro-mechanical modelling of unsaturated soils; numerical implementation and application to large deformation problems

This paper presents coupled hydro-mechanical modelling of unsaturated soil problems by incorporating some advanced numerical and constitutive models in a general-purpose commercial software package, Abaqus. Two different strategies for the interpretation of unsaturated soil behaviour with respect to the soil volume change are considered and the relevant constitutive models are implemented through user-defined subroutines. The first approach that is commonly used in geomechanics considers suction as an additional variable and uses a constitutive model in the space of effective stress–suction assuming that soil compressibility is a function of suction. The second approach treats the constitutive model in the space of effective stress and degree of saturation assuming that the soil compressibility is a function of the degree of saturation. The hydro-mechanical behaviour regarding the change in the degree of saturation caused by both suction and net stress changes is also considered, together with the effect of hydraulic hysteresis. Validation of the implemented algorithms is presented through several benchmark problems. Finally, the application and utility of the implemented procedures are illustrated by simulations of two challenging problems of unsaturated geomechanics, including a slope failure due to seepage and rainfall infiltration as well as cone penetration tests in unsaturated soil. A suitable mesh optimisation scheme is also incorporated to handle finite deformations.

Implementation and Validation of Casting Simulation Methodology for Diagnostics of Lamellar Graphite Iron

This paper describes and validates a methodology for implementation of full-scale sand-casting simulation in a general-purpose finite element software, including mold filling, heat transport, solidification kinetics, chemical microsegregation and prediction of microstructure and material properties. The solidification model, customized for gray cast iron, includes novel methods for handling interaction between parallel dendritic and eutectic solidification modes and its impact of their interaction on the final microstructure. The validation involves a previously published gray iron casting experiment and involves comparison of simulated and experimental cooling curves, microstructure parameters and tensile strength. We believe that this is valuable to researchers and engineers seeking to improve the state of the art of casting simulation tools.

Finite element solution of electro-magnetic-thermo-chemical problem in microwave assisted pultrusion processes

New finite element models and algorithms are developed for a solution of coupled electro-magnetic-thermo-chemical problem arising in microwave assisted pultrusion processes. In the first algorithm stage, the microwave set-up is predefined according to the requirements on energy-effectiveness and homogeneity of generated absorption field, in the second – an iterative procedure preserving the dependence of dielectric material properties on microwave frequency, temperature and degree of cure is applied to avoid resin overheating and flow from the die exit, and to guarantee a required profile quality. These holistic simulation tools are built by using the general-purpose finite element software ANSYS that makes available various modelling and analysis features of the finite element package and results in considerable savings in design time and costs. To demonstrate features and benefits of electromagnetic heating, the pultrusion process for a production of the rod profile with diameter of 16 mm and made of polyester resin POLRES 305 BV and glass fibers 4800 tex is developed. Based on the results of parametric study executed for the microwave assisted pultrusion set-ups with different ceramic dies, finite element modelling and coupled analysis aspects are discussed. • Coupled electro-magnetic-thermo-chemical problem has been formulated. • New finite element models and algorithms has been developed. • Finite element modelling and coupled analysis aspects have been discussed. • Microwave assisted pultrusion process has been developed.

Design guidelines and research directions for team analytics

PurposeThe purpose of this work is to illustrate the processes involved in managing teams in order to assist designers and developers to build software that support teamwork. A deeper investigation into the role of team analytics is discussed in this article.Design/methodology/approachMany researchers over the past several decades studied the success factors of a team. Despite many efforts, there is still no consensus on how a team should ideally be formed. Consequently, how one decides to form teams in a class depends on the domain, classroom context and pedagogical objectives. Therefore, software used to support an instructor in forming teams must be flexible enough to accommodate a variety of use cases and support the users throughout the lifecycle of teamwork. In this work, the author proposes a framework for designing general-purpose team management software. The author reviews existing team formation software and focuses specifically on opportunities for advancing research in team analytics.FindingsIn this context, the author identifies four areas of research opportunities for team analytics.Originality/valueLastly, the author proposes a series of research questions (RQs) and discusses the pedagogical, design, technical and social challenges involved.

A 146-dB-Ohm Gain 14-pARMS Noise Patch-Clamp Amplifier for Whole-Cell Ion Current Detection

The membrane clamp technique is an important tool to reflect the electrophysiological characteristics of cells by recording the ionic currents of cellular channels. Embedded systems work in systems designed for specific user groups and are used to implement specific functions. The membrane clamp amplifier built with embedded technology has the advantages of miniaturization, specialization, low power consumption, high integration, high resource utilization, and a long life cycle, which can avoid the inconvenience to developers and experimenters due to the update of general-purpose computer software and hardware. In this paper, a patch-clamp amplifier (PCA) based on a transimpedance amplifier (TIA) is proposed, which includes a glass microelectrode series resistance/capacitance compensation circuit and feedback resistor parasitic capacitance compensation. The prototype is designed using 180 nm CMOS technology and occupies an area of 720 μ m × 630 μ m . The prototype achieves a transimpedance gain of 145.6 dB-Ohm, a -3 dB bandwidth greater than 15 kHz, and an input reference noise current of 13.98 pARMS. Experimental results show that the proposed PCA is capable of compensating up to 30 pF of electrode capacitance and up to 10 MΩ for 86% of the series resistance, respectively. In addition, when the feedback resistor parasitic capacitance compensation circuit is enabled, the overshoot phenomenon disappears, overcoming the shortcomings of the conventional diaphragm clamp amplifier current clamp and maintaining the original key performance.

FDup: a framework for general-purpose and efficient entity deduplication of record collections.

Deduplication is a technique aiming at identifying and resolving duplicate metadata records in a collection. This article describes FDup (Flat Collections Deduper), a general-purpose software framework supporting a complete deduplication workflow to manage big data record collections: metadata record data model definition, identification of candidate duplicates, identification of duplicates. FDup brings two main innovations: first, it delivers a full deduplication framework in a single easy-to-use software package based on Apache Spark Hadoop framework, where developers can customize the optimal and parallel workflow steps of blocking, sliding windows, and similarity matching function via an intuitive configuration file; second, it introduces a novel approach to improve performance, beyond the known techniques of “blocking” and “sliding window”, by introducing a smart similarity matching function T-match. T-match is engineered as a decision tree that drives the comparisons of the fields of two records as branches of predicates and allows for successful or unsuccessful early-exit strategies. The efficacy of the approach is proved by experiments performed over big data collections of metadata records in the OpenAIRE Research Graph, a known open access knowledge base in Scholarly communication.

A Novel Design of a SIW-Fed Antenna Array Using an Accelerated Full-Wave Methodology

Arrays fed by substrate-integrated waveguides (SIWs) are a current topic of interest. However, most designers have to rely on general-purpose commercial software, usually inefficient for multiple full-wave simulations in a design process. This work proposes a new fast full-wave strategy, with very low iteration times, based on the simultaneous use of addition theorems for spherical and cylindrical modes. After a domain decomposition of the array into fixed or modifiable (to be optimized) sections, each section is analyzed using a finite-element/modal analysis to obtain its general scattering matrix. Fixed sections are only once coupled at the beginning, while each optimization iteration is calculated with full-wave precision by adding the interactions with the modifiable sections. A complete design process of a novel 16-slot progressive-wave SIW-fed array is performed to validate the strategy usefulness. 112800 iterations, with 47 optimization variables, are calculated in under 4 h (speed-up factor of over 2000 compared to general-purpose commercial software). The designed device is manufactured and experimentally characterized, measuring a 1.05 GHz <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\vert S_{11} \vert $ </tex-math></inline-formula> bandwidth under −10 dB and a maximum gain of 15.6 dBi at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\theta =-11^\circ $ </tex-math></inline-formula> in the array plane.

Cloud-based bug tracking software defects analysis using deep learning

Cloud technology is not immune to bugs and issue tracking. A dedicated system is required that will extremely error prone and less cumbersome and must command a high degree of collaboration, flexibility of operations and smart decision making. One of the primary goals of software engineering is to provide high-quality software within a specified budget and period for cloud-based technology. However, defects found in Cloud-Based Bug Tracking software’s can result in quality reduction as well as delay in the delivery process. Therefore, software testing plays a vital role in ensuring the quality of software in the cloud, but software testing requires higher time and cost with the increase of complexity of user requirements. This issue is even cumbersome in the embedded software design. Early detection of defect-prone components in general and embedded software helps to recognize which components require higher attention during testing and thereby allocate the available resources effectively and efficiently. This research was motivated by the demand of minimizing the time and cost required for Cloud-Based Bug Tracking Software testing for both embedded and general-purpose software while ensuring the delivery of high-quality software products without any delays emanating from the cloud. Not withstanding that several machine learning techniques have been widely applied for building software defect prediction models in general, achieving higher prediction accuracy is still a challenging task. Thus, the primary aim of this research is to investigate how deep learning methods can be used for Cloud-Based Bug Tracking Software defect detection with a higher accuracy. The research conducted an experiment with four different configurations of Multi-Layer Perceptron neural network using five publicly available software defect datasets. Results of the experiments show that the best possible network configuration for software defect detection model using Multi-Layer Perceptron can be the prediction model with two hidden layers having 25 neurons in the first hidden layer and 5 neurons in the second hidden layer.

Software development skills for health data researchers

Health data researchers are increasingly required to develop complex analytic code in order to implement sophisticated analyses on large health datasets. While writing analysis scripts ([box 1][1]) for academic projects...

Three-Dimensional-Printed Customized Orthodontic and Pedodontic Appliances: A Critical Review of a New Era for Treatment

Three-dimensional (3D) designing and manufacturing technology is a direct derivative of digital technology. Three-dimensional volume and surface acquisition, CAD software, and 3D manufacturing are major changes included in daily practice in many orthodontic and pedodontic offices. Customized appliances can be designed using dental CAD software or general-purpose CAD software in the office or a laboratory. Materials that can be used are resins, alloys, or zirconia. Methods: The search strategy of this critical review included keywords in combination with MeSH terms in Medline, Scopus, and Cochrane Library up to June 2022 in the English language without any limit to the publication period. Results: According to our search, 12 articles were selected for our study. All the articles were in vitro prospective studies. Conclusions: The results suggested that almost all the known appliances can be designed and printed in a tailor-made fashion in contrast to the traditional one-size-fits-all approach. Customized appliances should be manufactured according to the patient’s needs, and this is justified by the certainty that this approach will be beneficial for the patient’s treatment. There is a need for more research on all direct 3D-printed appliances.

A comparison of two frameworks for multi-state modelling, applied to outcomes after hospital admissions with COVID-19.

We compare two multi-state modelling frameworks that can be used to represent dates of events following hospital admission for people infected during an epidemic. The methods are applied to data from people admitted to hospital with COVID-19, to estimate the probability of admission to intensive care unit, the probability of death in hospital for patients before and after intensive care unit admission, the lengths of stay in hospital, and how all these vary with age and gender. One modelling framework is based on defining transition-specific hazard functions for competing risks. A less commonly used framework defines partially-latent subpopulations who will experience each subsequent event, and uses a mixture model to estimate the probability that an individual will experience each event, and the distribution of the time to the event given that it occurs. We compare the advantages and disadvantages of these two frameworks, in the context of the COVID-19 example. The issues include the interpretation of the model parameters, the computational efficiency of estimating the quantities of interest, implementation in software and assessing goodness of fit. In the example, we find that some groups appear to be at very low risk of some events, in particular intensive care unit admission, and these are best represented by using ‘cure-rate’ models to define transition-specific hazards. We provide general-purpose software to implement all the models we describe in the flexsurv R package, which allows arbitrarily flexible distributions to be used to represent the cause-specific hazards or times to events.