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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Undergraduate nursing students’ satisfaction with low- and high-fidelity simulation

Fatane, Sumayah 14 January 2016 (has links)
Few studies have focused on evaluating nursing students' satisfaction with different types of simulation, and in particular using valid and reliable instruments. A descriptive, cross-sectional and retrospective post-test study was conducted to examine nursing students’ satisfaction with low-fidelity simulation (LFS) and high-fidelity simulation (HFS). Thirty-five 4th year nursing students who met the eligibility criteria completed the Satisfaction with Simulation Experience Scale (SSE) and a demographic questionnaire via Fluidsurvey. A paired t-test analysis revealed a significant difference in the CL subscale mean scores between LFS (M = 4.09) and HFS (M = 3.78), p = 0.008. The ranking question revealed that the opportunities to practice new skills, and to apply clinical reasoning and decision-making were among the top three ranked features for both LFS and HFS. Also included in the top three ranked items identified for LFS was the preparation of materials and orientation and for HFS was engagement and realism. / February 2016
62

Apports de la logique mathématique en ingénierie des exigences

Garion, Christophe 12 1900 (has links) (PDF)
This thesis deals with requirements engineering (RE). RE characterizes the process leading to consistent set of specifications about some product. We have identified three distinct phases in RE process: requirements modelling, inconsistency management and requirements distribution. In the modelling phase, we have used CO, a logic of preferences, which has allowed us to express each agent's requirements in an ordonned way, but also domain constraints and complex normative sentences. We have then defined the notion of consistency between those three notions. Concerning the possible conflicts between requirements emitted by different agents, we have developped MF, a modal logic allowing to reason on belief bases obtained by majority merging. We have also developped Prolog automatic prover for MF. We have then shown that our approach allows to reason on ordonned or unordonned requirements sets. Finally, we have proposed to include in the RE process a distribution phase. The requirements are distributed among a set of executive agents. We have defined a simple model of agency from which we can derive the agent's goals. We have then extended this approach to multiagents systems and defined a distribution model based on a central entity controlling the distribution process.
63

The use of interactive computer simulations to engender conceptual changes about wave motion

Jacob, Sunny January 2001 (has links)
Computers are expensive equipment which most schools in South Africa cannot afford to use as an instructional tool in the same way as they are being used in affluent schools in the countly and in the western world. In this study a computer was used as a demonstration tool to help learners to visualise the different aspects of wave motion with the aid of interactive computer simulations. The study investigated how learners alter their intuitive notions of wave motion after experiencing the common teaching techniques in township schools, and then by observing interactive computer simulations. Data was collected by means of field notes, observation, questionnaires and in-depth semi-structured interviews with the participation of twelve Grade 9 learners in a secondary school over a three-week period. A combination of qualitative and quantitative methods was used in the study and the data was analysed within an interpretive framework. A detailed analysis revealed that interactive computer simulations could bring about positive conceptual changes in learners, especially in the micro level aspects of wave motion. The inexperience of the learners in a discovery method of learning and a learner centred approach of teaching seemed to interfere with the teaching techniques. To a considerable extent, language problems also hindered the revelation of conceptualisation.In writing this report of the research study J agree wilh Squires and McDougall (1994: 12) that it is difficult to use a non-interactive medium (paper-based text) to report on the interactive medium of computer simulations, as written words cannot bring out all the essential aspects of interactive computer simulations.
64

A supervisor to monitor multiple simulators

McRae, Robert Norman January 1972 (has links)
The problem treated in this thesis is to create a system to monitor multiple interacting simulators. The problem is encountered in an attempt to simulate urban growth. The resulting system has a supervisor which controls all of the components of the system, namely the I/O routines, the graphics routine, the command routines, and the simulators. The main task of the supervisor is to display whichever data values the user desires. This involves executing some simulators, and extracting the data values from the data base. The extraction process first finds an association path between the files in the data base in order to relate the variables being displayed. Then using the association path the physical values are extracted from the data base. The data values are then passed to the graphics routine to be displayed for the user. / Science, Faculty of / Computer Science, Department of / Graduate
65

SIMQ: a methodology for simulation by questionnaire

Goulet, Maurice Eugene January 1978 (has links)
This paper presents SIMQ, a method of simulation program generation through questionnaires. Simulation is a powerful technique for analyzing complex systems; Hut its, acceptance has been impeded by the high cost of computer simulations. The objective of SIMQ is to enhance the usefulness of computer simulation by reducing the cost of developing simulation programs. Related research is reviewed in order to outline the development of the concept of program generation and to provide a standard of comparison for SIMQ. The structure and use of SIMQ is explained and then illustrated through application to a demonstration problem. Initially, the discussion centers on a basic version of SIMQ. Subsequently an extension of SIMQ is presented which permits stochastic branching within the model. Finally, an interactive graphical front end for the SIMQ system is described. Several experiments were conducted to test SIMQ's efficiency and characteristics. Results of field tests are also reported. Possible further extensions to SIMQ are outlined in the final chapter. The major conclusion reached is that the concept of program generation through questionnaires is feasible and that the structure of the SIMQ system is valid and useful. / Business, Sauder School of / Graduate
66

Modélisation et commande d’un système de cogénération utilisant des énergies renouvelables pour le bâtiment / Modelling and control of combined heat and power system using renewable energy for the building

Brou, N'guessan Bahet Stanislas 12 October 2015 (has links)
Le contexte environnemental et énergétique actuel impose la mise en place de diverses politiques de maîtrise de l'énergie dont l'objectif finale consiste en une utilisation optimale des ressources énergétiques disponibles. Particulièrement en France, le secteur du bâtiment est le plus énergivore et aussi le plus gros gisement d'économie d'énergie et sans doute l'un des plus importants de réduction d'émission des gaz à effet de serre. Face à ce sujet majeur, la cogénération représente une solution de choix pour satisfaire aux besoins énergétiques de ce secteur. C'est dans ce cadre que nous développons, en association avec la société ENS2R, un simulateur numérique de comportement énergétique de système de cogénération couplé à un bâtiment. D'une part, des modèles numériques des différents composants de la plateforme de simulation ont été développés et validés et d'autre part des règles de contrôle-commande ont été élaborées et testées puis l'ensemble a été intégré dans l'environnement Simulink. A l'aide de cet outil d'aide au choix, les simulations dynamiques effectuées ont permis dans un premier temps d'évaluer les performances d'une configuration du système BATIMAC couplé à un bâtiment donné et d'en juger de la satisfaction des occupants par rapport à la stratégie de fonctionnement adoptée, puis des études paramétriques ont conduit à une configuration optimisée de l'installation selon différents régimes de fonctionnement. / The current environmental and energy context requires various policies of energy management whose final objective is a best use of available energy resources. Particularly in France, the building sector is the most energy-consuming and also the largest energy saving deposit and probably one of the largest emission reduction of greenhouse gasses. Deal with this major issue, combined heat and power plant is an excellent solution to meet the energy needs of this sector. It is in this framework that we develop, in association with the ENS2R Company, a numerical simulator of energy behavior CHP plant coupled with a building. First, the numerical models of various components have been developed and validated and secondly control rules have been developed and tested and all were integrated in the Simulink environment. Using this decision support tool, dynamics simulations were performed in a first step to evaluate the performance of one configuration of BATIMAC plant coupled to a building and to judge it the satisfaction of the occupants with regard to the operating strategy adopted then parametric studies led to an optimized configuration of this plant according to different operating modes.
67

Numerical simulation of the casting process

Bowles_HC 27 September 2023 (has links) (PDF)
The increasingly competitive market for cast products has required the development of higher quality and lower cost products. Although conventional process development techniques have improved, the cost and time associated to process development needs to be reduced. A faster and more cost-effective development method is required. Numerical modelling techniques provide a means by which casting design and process parameters can be optimized with minimum use of prototypes. This thesis reviews the current state of the art in solidification modelling. A typical casting problem is modelled, and the numerical results compared against measured temperatures. further work is required to from this investigation it is concluded that obtain, and accurately model the material properties and complex radiation behaviour within the fibrous insulation.
68

Using computer simulation to reduce costs at a recirculating aquaculture facility

Simon, John 24 May 2005 (has links)
The Recirculating Aquaculture System can be considered as a dynamic system in which the system variables change instantaneously during the growing period. This effort uses a combination of discrete and continuous simulation to model this system. Changing the values of a certain set of variables (regressors) result in changes to another set of variables (responses). So the inter relationship between the regressors and responses are first defined. Then the changes to the regressors are defined as a function of time. The computer program then simulates time from the beginning to the end of the growing period. By attaching cost factors, the cost of running the system during the growing period can be obtained. In a real facility, some of the regressors can be changed by the operator, affecting the overall cost. So, in this model, different values for this subset of regressors are tried out using a proprietary heuristic called "Optquest" to arrive at a low cost configuration. Some of the responses are also constrained while trying to minimize the cost, e.g., ammonia level. The output of the model gives a cost savings of about $10,000 over a period of 8 months for a facility with 12 tanks by suggesting optimal values for the water replenishment rate, water recirculation rate, oxygen supply rate and feeds per day. / Master of Science
69

Distributed simulation of power systems using real time digital simulator

Gubba Ravikumar, Krishnanjan 08 August 2009 (has links)
The simulation of power system behavior, especially transient behavior, helps us in the analysis and planning of various power systems. However, power systems are usually highly complex and geographically distributed. Therefore system partitioning can be used to allow for sharing resources in simulation. In this work, distributed simulations of power system models have been developed using an electromagnetic transient simulator, namely Real Time Digital Simulator (RTDS). The goal is to demonstrate and assess the feasibility of both non-real-time and real-time simulations using the RTDS in a geographically distributed scenario. Different protocols and options used in the communication between power systems have been studied and analyzed. In this work, a test bed has been developed for data transfer between a power system simulated in RTDS at Mississippi State University and the power system simulated in RTDS at Texas A&M University. Different protocols, available for the interface and communication in the RTDS, have been studied and applied in this work. Finally, a locally distributed wide area control test bed was developed and simulated.
70

Development of Magnetic Nozzle Simulations for Space Propulsion Applications

Glesner, Colin Christopher 06 February 2017 (has links)
A means of space propulsion using the channeling of plasma by a divergent magnetic field, referred to as a magnetic nozzle has been explored by a number of research groups. This research develops the capability to apply the high order accurate Runge-Kutta discontinuous Galerkin numerical method to the simulation of magnetic nozzles. The resistive magnetohydrodynamic model of plasma behavior is developed for these simulations. To facilitate this work, several modeling capabilities are developed, including the implementation of appropriate inflow and far-field boundary conditions, the application of a technique for correcting errors that develop in the divergence of the magnetic field, and a split formulation for the magnetic field between the applied and the perturbed component. This model is then applied to perform a scaling study of the performance of magnetic nozzles over a range of Bk and Rm. In addition, the effect of the choice of simulation domain size is investigated. Finally, recommendations for future work are made. / Master of Science / In order for human kind to expand our reach beyond the Earth, and create a meaningful human presence throughout the solar system, it is almost certain that the current means of propelling spacecraft will be insufficient. With current propulsion systems that derive their energy from chemical reactions, there is an upper limit to how energetic a chemical reaction can be. This fact, together with the fact that a spacecraft must carry all of its fuel with it, means that interplanetary trips with chemical rockets require an impractically large amount of fuel. Other means of propulsion which do not have an upper limit on the energy that can be used to power the spacecraft are available. One such method, referred to as a Helicon Thruster, or a Magnetic Nozzle thruster, works as follows: first, an inert gas is introduced into the thruster. Then, a powerful antenna is used to break electrons off of the atoms of the gas, which generates ions (atoms that have had one or more of their electrons removed). This results in what is know as a plasma, or a gas made up entirely of charged particles. Common examples of plasma are lightning bolts, the gas inside of fluorescent lights, and the sun. Plasmas differ from normal gasses in that they feel the effects of magnetic and electric fields, and can conduct electricity. Once this plasma has been generated inside of the thruster, another antenna may be used to further heat up the plasma. Then, the plasma is directed by a strong magnetic field out the back of the thruster, propelling the spacecraft forward. This propulsion technique requires much less fuel than traditional chemical approaches, making long interplanetary trips more practical. A number of research questions need to be answered before this propulsion method can be put into practice. This thesis contributes to this effort by building the tools necessary to run a computer simulation of the magnetic field that is used to channel the plasma used by this propulsion technique.

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