Search results for "Simulation"

Organizing for collaboration in simulation-based environments : an affordance perspective

2023

Extant research has identified the significance of technological affordances in computer-supported learning environments. However, until recently, there is scarcely empirical research on affordances for organizing collaboration in these learning environments. To address this gap, this study empirically examines affordances for organizing collaboration in a simulation-based learning environment. We focus, in particular on understanding how the organizing affordances of the learning environment are perceived and employed by the learners during a simulation-based learning task. The study was executed among 177 undergraduate higher education (HE) business students from 10 universities in Belgiu…

Refined instability estimates for some inverse problems

2022

Many inverse problems are known to be ill-posed. The ill-posedness can be manifested by an instability estimate of exponential type, first derived by Mandache [29]. In this work, based on Mandache's idea, we refine the instability estimates for two inverse problems, including the inverse inclusion problem and the inverse scattering problem. Our aim is to derive explicitly the dependence of the instability estimates on key parameters. The first result of this work is to show how the instability depends on the depth of the hidden inclusion and the conductivity of the background medium. This work can be regarded as a counterpart of the depth-dependent and conductivity-dependent stability estim…

Shape optimization utilizing consistent sensitivities

2010

Collision Avoidance with Potential Fields Based on Parallel Processing of 3D-Point Cloud Data on the GPU

2014

In this paper we present an experimental study on real-time collision avoidance with potential fields that are based on 3D point cloud data and processed on the Graphics Processing Unit (GPU). The virtual forces from the potential fields serve two purposes. First, they are used for changing the reference trajectory. Second they are projected to and applied on torque control level for generating according nullspace behavior together with a Cartesian impedance main control loop. The GPU algorithm creates a map representation that is quickly accessible. In addition, outliers and the robot structure are efficiently removed from the data, and the resolution of the representation can be easily ad…

Transition 8: 800-1200. Emergence of enduring, concentrated and hierarchised settlement patterns in rural regions of North-Western Europe

2021

Chapter 11 : https://books.openedition.org/pufr/19927; International audience

Structural Parameters under Partial Least Squares and Covariance-Based Structural Equation Modeling : A Comment on Yuan and Deng (2021)

2023

In their article, Yuan and Deng argue that a structural parameter under partial least squares structural equation modeling (PLS-SEM) is zero if and only if the same structural parameter is zero under covariance-based structural equation modeling (CB-SEM). Yuan and Deng then conclude that statistical tests on individual structural parameters assessing the null hypothesis of no effect can achieve the same purpose in CB-SEM and PLS-SEM. Our response to their article highlights that the relationship they find between PLS-SEM and CB-SEM structural parameters is not universally valid, and that consequently, tests on individual parameters in CB-SEM and PLS-SEM generally do not fulfill the same pur…

Monotone generalized nonlinear contractions and fixed point theorems in ordered metric spaces

2011

The purpose of this paper is to present some fixed point theorems for T -weakly isotone increasing mappings which satisfy a generalized nonlinear contractive condition in complete ordered metric spaces. As application, we establish an existence theorem for a solution of some integral equations.

Enabling Energy Savings in Offshore Mechatronic Systems by using Self-Contained Cylinders

2019

This paper proposes a novel actuation system for an offshore drilling application. It consists of three self-contained electro-hydraulic cylinders that can share and store regenerated energy. The energy saving potential of the proposed solution is analyzed through a multibody system simulation. The self-contained system demonstrates superior energy efficiency compared to the benchmark system representing the state-of-the-art approach used today (i.e., valve-controlled cylinders by means of pressure-compensated directional control valves and counter-balance valves, supplied by a centralized hydraulic power unit). Due to the power on demand capability, the cancellation of the throttling losse…

ANALYSIS OF THE TRADITIONAL PASSIVE SYSTEMS PERFORMANCE THROUGH THE APPLICATION OF CFD SOFTWARE

2012

The need to reduce energy consumption is pushing the building design research to the evaluation of passive conditioning systems, since urban buildings are one of the major energy dissipater resulting in emission of CO2. This approach is not modern, but it is historically rooted in the architectural culture of the Mediterranean area and in the Middle East. The passive systems have ancient origins: they were developed to mitigate the summer heat and the winter cold. To understand the reasons that led to the development of passive systems, it should be remembered that about One-Fifth of the emerged planet surface and One-Third of the world's population live in conditions of warm-dry or hot-hum…

Iterative Learning Applied to Hydraulic Pressure Control

2018

This paper addresses a performance limiting phenomenon that may occur in the pressure control of hydraulic actuators subjected to external velocity disturbances. It is demonstrated that under certain conditions a severe peaking of the control error may be observed that significantly degrades the performance of the system due to the presence of nonlinearities. The phenomenon is investigated numerically and experimentally using a system that requires pressure control of two hydraulic cylinders. It is demonstrated that the common solution of feed forwarding the velocity disturbance is not effective in reducing the peaking that occurs as a result of this phenomenon. To improve the system perfor…