Tesi sul tema "Validated simulation"
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1
Kambourides, Miltos E. "Nonparametic-validated computer-simulation surrogates : a Pareto formuation". Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/43931.
2
Stainton, Andrew. "To what extent can total enterprise simulation be validated?" Thesis, University of Southampton, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438665.
3
Hobson, P. A. "Thermosyphon solar water heaters : validated numerical simulation and design correlations". Thesis, Cranfield University, 1988. http://hdl.handle.net/1826/4361.
Abstract (sommario):
A detailed analysis of the heat transfers and fluid flows within a
direct thermosyphonic solar-energy water-heater has been undertaken.
The collector energy equations when cast in a two-dimensional form
enabled heat transfer and thermal capacitance effects to be simulated
accurately at the small flow rates encountered commonly in such
systems. An investigation of thermocline relaxation processes within
the store indicated negligible mixing at the store inlet over a wide
range of Richardsons numbers (43,608 < Ri < 729,016). Thermal
relaxation under conditions of no flow was shown to be due
predominantly to axial conduction along the store wall. The use of an
appropriate non-isothermal friction factor correlation when calculating
frictional losses in the collector's riser pipes, produced predicted
steady-state flow rates which were corroborated experimentally to
within 2%. An indoor test facility, monitored and controlled by a
microcomputer, enabled "real" operating conditions to be simulated. The
predicted responses of the system to identical conditions showed good
agreement with the corresponding experimental observations, the
predicted heat delivery being within 2.8% of the measured value.
A technique for correlating the daily performances of thermosyphon
solar-energy water-heaters has been developed. The five dimensionless
groups which form the basis of the correlations and the functional
relationships between these groups were derived from an analytical
solution of a linear first-order differential transient heat balance
carried out on a generic system. Thermal performance data used in the
correlations was generated by the numerical simulation using
representative U. K. hourly weather data and operating conditions. The
minimum amount of data required to establish a characteristic curve for
an individual system was found to be thirty days. Using such a curve,
the total annual solar fraction agreed with that predicted by the high
level model to within 3%. Two universal curves were determined in which
the gradients of characteristic curves were correlated against the
derived dimensionless groups. The accuracy of the resulting two-stage
algorithm in determining annual solar fractions was established as
ranging from 5.5% for predominantly multiple-pass systems to a mean of
10.5% for single-pass systems.
4
MaxeÌ, n. Fredrik. "Comparative analysis of network approaches for tactical wireless communications, validated by Joint Communication Simulation System (JCSS) simulations a Swedish perspective". Thesis, Monterey, California. Naval Postgraduate School, 2011. http://hdl.handle.net/10945/5555.
Abstract (sommario):
Approved for public release; distribution is unlimited.This thesis project explores two approaches for military tactical wireless communications solutions in the context of being useful for the Swedish Armed Forces. The study's tactical perspective focuses on a force of battalion size. The two network approaches, ad hoc networking and infrastructure based, were analyzed and compared via simulation. As a baseline for this thesis project, research was initiated based on appropriate communication requirements for the tactical force. This was followed by background research into current technologies for ad hoc networking and infrastructure-based systems. In order to analyze and compare the two technology approaches, a model was developed using the software Joint Communication Simulation System (JCSS) and a battalion-sized network simulation using ad hoc and infrastructure-based technology. This thesis project addressed tactical force requirements from the perspective of the basic Swedish Armed Forces principle for command and control, which is Maneuver Warfare. Evaluation of the technologies is discussed through the important perspectives of capacity, mobility, flexibility, robustness, interoperability, and cost. By analyzing the technology approaches from these perspectives, this thesis project attempts to provide the Swedish Armed Forces with more information and understanding, which in-turn will allow better-suited future developments of all tactical wireless communication systems.
5
Duracz, Adam. "Rigorous Simulation : Its Theory and Applications". Doctoral thesis, Högskolan i Halmstad, Centrum för forskning om inbyggda system (CERES), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-32608.
Abstract (sommario):
Designing Cyber-Physical Systems is hard. Physical testing can be slow, expensive and dangerous. Furthermore computational components make testing all possible behavior unfeasible. Model-based design mitigates these issues by making it possible to iterate over a design much faster. Traditional simulation tools can produce useful results, but their results are traditionally approximations that make it impossible to distinguish a useful simulation from one dominated by numerical error. Verification tools require skills in formal specification and a priori understanding of the particular dynamical system being studied. This thesis presents rigorous simulation, an approach to simulation that uses validated numerics to produce results that quantify and bound all approximation errors accumulated during simulation. This makes it possible for the user to objectively and reliably distinguish accurate simulations from ones that do not provide enough information to be useful. Explicitly quantifying the error in the output has the side-effect of leading to a tool for dealing with inputs that come with quantified uncertainty. We formalize the approach as an operational semantics for a core subset of the domain-specific language Acumen. The operational semantics is extended to a larger subset through a translation. Preliminary results toward proving the soundness of the operational semantics with respect to a denotational semantics are presented. A modeling environment with a rigorous simulator based on the operational semantics is described. The implementation is portable, and its source code is freely available. The accuracy of the simulator on different kinds of systems is explored through a set of benchmark models that exercise different aspects of a rigorous simulator. A case study from the automotive domain is used to evaluate the applicability of the simulator and its modeling language. In the case study, the simulator is used to compute rigorous bounds on the output of a model.
6
Niazi, Muaz A. K. "Towards a novel unified framework for developing formal, network and validated agent-based simulation models of complex adaptive systems". Thesis, University of Stirling, 2011. http://hdl.handle.net/1893/3365.
Abstract (sommario):
Literature on the modeling and simulation of complex adaptive systems (cas) has primarily advanced vertically in different scientific domains with scientists developing a variety of domain-specific approaches and applications. However, while cas researchers are inherently interested in an interdisciplinary comparison of models, to the best of our knowledge, there is currently no single unified framework for facilitating the development, comparison, communication and validation of models across different scientific domains. In this thesis, we propose first steps towards such a unified framework using a combination of agent-based and complex network-based modeling approaches and guidelines formulated in the form of a set of four levels of usage, which allow multidisciplinary researchers to adopt a suitable framework level on the basis of available data types, their research study objectives and expected outcomes, thus allowing them to better plan and conduct their respective research case studies. Firstly, the complex network modeling level of the proposed framework entails the development of appropriate complex network models for the case where interaction data of cas components is available, with the aim of detecting emergent patterns in the cas under study. The exploratory agent-based modeling level of the proposed framework allows for the development of proof-of-concept models for the cas system, primarily for purposes of exploring feasibility of further research. Descriptive agent-based modeling level of the proposed framework allows for the use of a formal step-by-step approach for developing agent-based models coupled with a quantitative complex network and pseudocode-based specification of the model, which will, in turn, facilitate interdisciplinary cas model comparison and knowledge transfer. Finally, the validated agent-based modeling level of the proposed framework is concerned with the building of in-simulation verification and validation of agent-based models using a proposed Virtual Overlay Multiagent System approach for use in a systematic team-oriented approach to developing models. The proposed framework is evaluated and validated using seven detailed case study examples selected from various scientific domains including ecology, social sciences and a range of complex adaptive communication networks. The successful case studies demonstrate the potential of the framework in appealing to multidisciplinary researchers as a methodological approach to the modeling and simulation of cas by facilitating effective communication and knowledge transfer across scientific disciplines without the requirement of extensive learning curves.
7
Bertin, Étienne. "Robust optimal control for the guidance of autonomous vehicles". Electronic Thesis or Diss., Institut polytechnique de Paris, 2022. http://www.theses.fr/2022IPPAE012.
Abstract (sommario):
Le guidage d'un lanceur réutilisable est un problème de contrôle qui nécessite à la fois précision et robustesse : il faut calculer une trajectoire et un contrôle, de sorte que le lanceur atteigne la piste d'atterrissage, sans s'écraser ni exploser en vol, le tout en utilisant le moins de carburant possible.Les méthodes de Contrôle Optimal issu du Principe de Pontryagin calculent une trajectoire optimale avec grande précision, mais les incertitudes, soit les erreurs entre les estimations de l'état initial et des paramètres et leurs valeurs réelles, causent une déviation potentiellement dangereuse de la trajectoire réelle. En parallèle, les méthodes ensemblistes et notamment la simulation validée peuvent encadrer toutes les trajectoires possibles d'un système dynamique avec des incertitudes bornées.Cette thèse combine ces deux approches pour encadrer des ensembles de trajectoires optimales de systèmes avec incertitudes afin de garantir la robustesse du guidage d'un véhicule autonome.Nous commençons par définir des ensembles de trajectoires optimales pour des systèmes avec incertitudes, d'abord pour les trajectoires mathématiquement parfaites, puis pour les trajectoires d'un véhicule sujet à des erreurs d'estimation, mais qui utiliserait, ou non, les données des capteurs pour recalculer sa trajectoire en cours de route. Le principe de Pontryagin caractérise ces ensembles comme solutions de problèmes aux deux bouts avec des dynamiques avec incertitudes. Nous développons alors des algorithmes qui encadrent toutes les solutions de ces problèmes aux deux bouts en utilisant la simulation validée, l'arithmétique des intervalles et la théorie des contracteurs. Cependant, la simulation avec des intervalles occasionne une forte sur-approximation qui limite nos méthodes. Pour y remédier, nous remplaçons les intervalles par des zonotopes symboliques contraints. Nous utilisons notamment ces zonotopes pour simuler des systèmes hybrides, encadrer des solutions de problèmes aux deux bouts et construire des sous-approximations en complément de la sur-approximation classique. Enfin, nous combinons tout ceci pour calculer des ensembles de trajectoires de systèmes aérospatiaux et les utilisons pour évaluer la robustesse du contrôleThe guidance of a reusable launcher is a control problem that requires both precision and robustness: one must compute a trajectory and a control such that the system reaches the landing zone, without crashing into it or exploding mid-flight, all while using as little fuel as possible. Optimal control methods based on Pontryagin's Maximum Principle can compute an optimal trajectory with great precision, but uncertainties, the discrepancies between estimated values of the initial state and parameters and actual values, cause the actual trajectory to deviate, which can be dangerous. In parallel, set-based methods and notably validated simulation can enclose all trajectories of a system with uncertainties.This thesis combines those two approaches to enclose sets of optimal trajectories of a problem with uncertainties to guarantee the robustness of the guidance of autonomous vehicles.We start by defining sets of optimal trajectories for systems with uncertainties, first for mathematically perfect trajectories, then for the trajectory of a vehicle subject to estimation errors that can use, or not use, sensor information to compute a new trajectory online. Pontryagin's principle characterizes those sets as solutions of a boundary value problem with dynamics subject to uncertainties. We develop algorithms that enclose all solutions of these boundary value problem using validated simulation, interval arithmetic and contractor theory. However, validated simulation with intervals is subject to significant over-approximation that limits our methods. To remedy that we replace intervals by constrained symbolic zonotopes. We use those zonotopes to simulate hybrid systems, enclose the solutions of boundary value problems and build an inner-approximation to complement the classical outer-approximation. Finally, we combine all our methods to compute sets of trajectories for aerospace systems and use those sets to assess the robustness of a control
8
Benson, Kristen D. "Use of centrifuge modelling to validate an unsaturated transport numerical simulation". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2002. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/NQ65665.pdf.
9
Papapanagiotou, Nikolaos, Eugen Constantin, Sanjeev Singh e Nikolaos Papapanagiotou. "Analysis of DDD and VDT simulation techniques to determine feasibility of using VDT simulation to validate DDD models". Monterey, California. Naval Postgraduate School, 2004. http://hdl.handle.net/10945/9925.
Abstract (sommario):
Approved for public release; distribution is unlimited.MBA Professional Report
Approved for public release; distribution is unlimited.
The purpose of this MBA project was to determine whether and how VDT can emulate the results obtained from A2C2 Experiments. To do that, we have first focused on learning the basics of VDT and DDD simulation techniques and then on how the models used in DDD can be analyzed using VDT. To this end, we obtained experimental data from DDD Experiment 8 and created representative models in VDT to determine the similarities and differences. We also kept detailed records of our research to assist individuals in the future who may want to expand on our work. The project involved studying of DDD and VDT techniques, establishing building blocks in VDT, creating a best effort model for DDD Experiment 8 and studying the various outcomes. In this project we could not successfully replicate the complex DDD Experiment 8 scenarios within VDT. However, important conclusions were drawn that would go a long way towards helping future studies in this regard.
10
Benezech, Laurent Jean-Michel Dimotakis Paul E. "Premixed hydrocarbon stagnation flames : experiments and simulations to validate combustion chemical-kinetic models /". Diss., Pasadena, Calif. : California Institute of Technology, 2008. http://resolver.caltech.edu/CaltechETD:etd-05302008-113043.
11
Miller, Craig. "A Research Based General Framework for Effective Simulation Development and Methodology to Validate Economic Fidelity". Thesis, Metropolitan State University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3668376.
Abstract (sommario):
The three primary objectives of this project were: (1) to identify and codify a framework for best practices in developing a simulation; (2) to construct a prototype or test simulation based on these best practices, and (3) to create a methodology to assess pedagogical efficacy and economic fidelity.
While the current body of knowledge is rich in describing the virtues and pitfalls of computer simulation technology that has existed for close to 60 years, the literature nonetheless lacks a codified set of best practices for developers and objective assessment methods to judge a simulation quality for both the pedagogical effectiveness and economic fidelity. This study addresses both issues and offers a solution that is unique and effective. A General Framework for Effective Simulation Development that is derivative, and an extension of existing research in the business simulation domain. A simulation prototype, SimWrite!, has been developed that is consistent with the 12 elements identified in this framework. Each stage of the development of this test simulation is explicitly tied to the best practices that emerged from the literature. A second assessment tool, The Economic Theory Input-Output Matrix, is presented to enable a user to measure the economic fidelity of a simulation. This tool is based on microeconomic theory that is taught at business schools throughout the globe. Both assessment tools will be applied to the test simulation in a manner that will enable the user to replicate this research with other simulations they are interested in. The products of this dissertation are intended to aid current and future developers make better simulations and faculty users of simulations to better select simulations that will help them to achieve the goal of all involved in teaching business: To produce greater learning for students.
12
Singer, Gideon. "Methods for Validatng Cockpit Design The best tool for the task". Doctoral thesis, KTH, Aeronautical Engineering, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3315.
13
Shaw, J. "Use of plant growth simulations to validate BRDF model parameters derived SPOT-VGT data". Thesis, Swansea University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.639015.
Abstract (sommario):
By inverting BRDF models against satellite-sensor measurements of spectral reflectance recorded at different illumination and view angles, it is theoretically possible to obtain estimates of several important environmental variables (e.g., LAI, albedo). In recent years, a growing number of studies has exploited this basic approach, however, the relationships between the resulting model-derived quantities and the corresponding surface properties have yet to be rigorously explored. This thesis examines these relationships, by comparing upscaled observations of LAI with the outputs of BRDF model inversions. The research makes use of ground-base measurements of LAI, albedo, spectral reflectance and canopy biometric characteristics for a variety of arable crops over two growing seasons (1999/2000). These data sets are, however, recorded at very different spatial and temporal scales compared to the satellite-sensor data employed as input to the BRDF models (c.1km). The former data set was, therefore, upscaled to match the satellite data. Upscaling is achieved using a combination of plant growth models and intermediate spatial resolution satellite-sensor images. The plant growth models, in particular SUCROS, are used to provide estimates of LAI over the full growing season. These temporal profiles of LAI are up-scaled to the 1km spatial resolution of the SPOT-VGT image data employed in the BRDF model inversions using image data acquired by the Lansat-TM sensor. These data are used to generate a land cover map of the study area (84% accuracy). The simulated temporal profiles of LAI are applied to this land cover map on a cover-type by cover-type basis to generate images of LAI, initially at 30m resolution and, subsequently, at 1km resolution. In theory, the kernel weights are related to surface biophysical properties, however, it was subsequently determined that, in the case of LAI, this was not so. Therefore, evidence that the kernel weights may be related to LAI is sought by comparison of the temporal profiles of up-scaled LAI with temporal profiles of up-scaled LAI with temporal profiles of the kernel weights. Although positive correlation with the other kernel weights. It was, however, found that the up-scaled LAI was strongly correlated with the NDVI and the corrected NDVI than with the kernel weights.
14
Sturisky, Selwyn H. "A linear system identification and validaton of an AH-64 apache aeroelastic simulation model". Diss., Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/13402.
15
Ghita, Monica. "Computer simulations to estimate organ doses from clinically validated cardiac, neuro, and pediatric protocols for multiple detector computed tomography scanners". [Gainesville, Fla.] : University of Florida, 2009. http://purl.fcla.edu/fcla/etd/UFE0025006.
16
Miller, Mark Stephen. "Use of osmotic coefficient measurements to validate and to correct the interaction thermodynamics of amino acids in molecular dynamics simulations". Diss., University of Iowa, 2018. https://ir.uiowa.edu/etd/6476.
Abstract (sommario):
Molecular dynamics simulations are an increasingly valuable tool to biochemical researchers: advances in computational power have expanded the range of biomolecules that can be simulated, and parameters describing these interactions are increasingly accurate. Despite substantial progress in force field parameterization, recent simulations of protein molecules using state-of-the-art, fixed-charge force fields revealed that the interactions among and within protein molecules can be too favorable, resulting in unrealistic aggregation or structural collapse of the proteins being simulated. To understand why these protein-protein interactions are so over-stabilized, I first assessed the ability of simulation force fields to represent accurately the interactions of individual amino acids, employing an osmotic pressure simulation apparatus that enabled direct comparison with experiment. Surprisingly, simulations of most of the amino acids resulted in behavior that was in strong agreement with experiment. A number of amino acids, however—notably those that contain hydroxyl groups and those that carry a formal charge—interacted in ways that were clearly inaccurate. Additionally, some commonly-used force fields failed to accurately represent the interactions of amino acids in a consistent manner. By further investigating the interactions of the functional groups of these amino acids, I was able not only to determine some of the root causes of individual amino acid inaccuracies, but also to implement simple modifications that brought the interactions of these small molecules and amino acids in stronger accord with experiment. These studies have highlighted some of the shortcomings in popular simulation force fields, and have proposed useful modifications to address them. Still, there is additional work that must be—and is being—conducted in order to correctly model the interaction behavior of proteins in simulation.
17
MALIZIA, ANDREA. "Dust mobilization problem in an experimental nuclear reactor: experiments with stardust and simulations to validate a first re-suspension numerical model". Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2010. http://hdl.handle.net/2108/1325.
Abstract (sommario):
A recognized safety issue for future fusion reactors fueled with deuterium and tritium is the generation of sizeable quantities of dust. Several mechanisms [like plasma disruptions, Edge Localized Modes (ELM) and Vertical Displacement Events (VDE)] resulting from material response to plasma bombardment in normal and off-normal conditions are responsible for generating dust of micron and sub-micron length scales inside the VV (Vacuum Vessel) of experimental fusion reactors like the International Thermonuclear Experimental Reactor (ITER). The loss of coolant accidents (LOCA), loss of coolant flow accidents (LOFA) and loss of vacuum accidents (LOVA) are types of accidents expected in experimental fusion reactors like ITER, which may jeopardize the components and the plasma vessel integrity and cause dust mobilization risk for workers and public. A small facility, Small Tank for Aerosol Removal and DUST (STARDUST), was set up to perform experiments concerning the dust mobilization in a volume with the initial condition similar to those existing in ITER VV.
The aim of this work was to reproduce a low pressurization rate (300 Pa/s) LOVA event in ITER due to a small air leakage, for two different positions of the leak, at the equatorial port level and at the divertor port level, in order to evaluate a first re-suspension numerical model by the analysis of the:
1. influence of obstacles and temperature on dust resuspension during both maintenance and operative conditions;
2. The velocity field inside STARDUST.
For the first experimental purpose the dusts used were tungsten (W), stainless steel (SS) and carbon (C), similar to those produced inside the vacuum chamber in a fusion reactor when the plasma facing materials vaporizes due to the high energy deposition. The experimental campaign has been carried out by introducing inside STARDUST facility an obstacle to simulate the presence of objects, like divertor and the limiter-divertor gap inside ITER VV at different temperatures (25�C maintenance conditions, 110�C during operative conditions).
For the second experimental purpose, local measurements of velocity have been acquired by means of a capacitive transducer.
A two-dimensional (2D) modelling of STARDUST was made with the commercial CFD code FLUENT, in order to get a preliminary overview of the fluid dynamics behaviour during a LOVA event and to justify the experimental evidence. The results of these simulations were compared against the experimental data for the CFD code validation.
For validation purposes, the CFD simulation data were extracted at the same locations as the experimental data were collected. In this work, the computer-simulation data and the comparison with data collected during the laboratory studies will be presented and discussed.
18
Bochníček, Štěpán. "Validace numerické simulace průběhu plnění matečné formy voskem a její následná optimalizace". Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-230975.
Abstract (sommario):
The main topic of the diploma thesis is simulation of the process when wax is filling the cavity of the "mother" metal die.This knowledge is the neccessary presumption for correct design of the gating system and setting correct injection parameters (temperature, pressure, wax flow) when making wax patterns.
19
Hoelzenbein, Angela C. [Verfasser], e Karl Christoph [Akademischer Betreuer] Klauer. "'Mind the Gap': Simulation studies to validate the quality of multiple imputation = 'Mind the Gap': Simulationsstudien zur Validierung der Güte von Multipler Imputation". Freiburg : Universität, 2015. http://d-nb.info/111924644X/34.
20
Mokrý, Michal. "In silico návrh a validace peptidových derivátů konotoxinu pro nanoterapii neuroblastomu". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442491.
Abstract (sommario):
Práca sa zaoberá in silico dizajnom a validáciou peptidov založených na konotoxíne - MrIA, izolovaného z morských slimákov druhu Conus marmoreus a možnosti využitia týchto peptidov v liečbe neuroblastómu pomocou cielenia norepinefrínového transportéru. Päť peptidov založených na tomto konotoxíne bolo simulovaných pomocou simulácii molekulárnej dynamiky, ich trajektórie boli analyzované pre zistenie vlastností týchto peptidov. Dva homologické modely ľudského norepinefrínového transportéru boli vytvorené pre analýzu väzobných vlastností peptidov založených na konotoxíne ku norepinefrínovému transportéru. Peptidy boli následne syntetizované a použité na pokrytie apoferitínových nanočastíc s elipticínom uväzneným vnútri apoferitínu. Vytvorené peptidy a nanočastice boli ďalej skúmané pre objasnenie ich fyzikálo-chemických vlastností. Interakcie a cytotoxicita boli skúmané aplokáciou nanočastíc na bunky neuroblastómu a epitelu. Z in silico a in vitro analýz vyšiel YKL-6 peptid ako najlepší kandidát na ďalší výskum.
21
Richtr, Jiří. "Využití diskrétní simulace při řízení výrobního procesu". Master's thesis, Vysoké učení technické v Brně. Fakulta podnikatelská, 2011. http://www.nusl.cz/ntk/nusl-223057.
Abstract (sommario):
Simulace výrobních procesů pomáhá optimalizovat výrobu, logistiku a další systémy, díky čemuž dochází ke snižování nákladů a racionalizaci vnitropodnikových procesů. Využitím diskrétní simulace programu Witness Power with Ease se v diplomové práci optimalizuje logistický tok materiálu ve společnosti Hella Autotechnik, s.r.o. Práce přibližuje metody a jednotlivé fáze tvorby modelu včetně jeho validace a navrhuje vylepšení, díky kterému by mělo dojít ke snížení nákladů na dopravní služby o 24 400 Kč měsíčně.
22
Raffai, Peter. "Modeling the Impact of Piston Rings on Oil Consumption of Internal Combustion Engines". Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-316144.
Abstract (sommario):
V rámci této práce byl vyvinut komplexní simulační nástroj, vycházející z výpočtového modelování fyzikálních a chemických dějů, který je doplněn vhodnými matematickými postupy. Výsledný software je schopen stanovit ztrátový výkon sady pístních kroužků pomocí účinků klíčových mechanismů a jejich vzájemné interakce při standardním provozu pístních kroužků. Simulační výstupy byly navrženy v souladu se zájmy průmyslové praxe, např. určení objemového toku plynů pístní skupinou, ztrátové výkony vlivem tření a spotřeba oleje, která je ovlivněna sadou pístních kroužků. Při vývoji simulačního modelu byly technické experimenty vykonány na tříválcovém zážehovém motoru za účelem získání vstupních dat a ověření výsledků. Možnosti navrženého simulačního nástroje jsou na tomto motoru dále demonstrovány v podobě parametrických studií, využitelných zejména při návrhovém procesu. Cílem dizertační práce bylo zaplnit mezeru ve výzkumné oblasti simulačních nástrojů, které mohou účinně propojit výpočtové modelování třecích ztrát a současně i spotřeby oleje, a podpořit tak výrobce pístních kroužků a vývojová oddělení spalovacích motorů.
23
Vrána, Jakub. "Optimalizace výrobního procesu ve společnosti". Master's thesis, Vysoké učení technické v Brně. Fakulta podnikatelská, 2013. http://www.nusl.cz/ntk/nusl-223905.
Abstract (sommario):
This thesis deals with the management of the production process, focusing on unproductive activities. It comprises analysis of the current situation in the company Teva Czech Industries s.r.o. (the TCI) and suggestions for improvement measures. The first chapter presents theoretical basis for processing work. PMT methods, namely MTM and MOST, lean production with a focus on 5S, TPM and Kaizen are described. The second chapter is focused on the company TCI, core business, organization structure and analyzes the current status. It’s focused primarily on the process of critical non-manufacturing operations and the changeover cleaning process. The third chapter, following the analytical part consists of the proposed recommendations. The fourth chapter deals with the final evaluation.
24
Vyhlídalová, Karolína. "Zásobník tepla solární soustavy". Doctoral thesis, Vysoké učení technické v Brně. Fakulta stavební, 2020. http://www.nusl.cz/ntk/nusl-433632.
Abstract (sommario):
The solar hot water storage tank is off great importance in the solar collector array. It allows transformed energy accumulation thus deals with the inconsistency between supply and demand. The suitable design of the storage tank can improve system efficiency. The storage capacity represents the balance between the amount of stored hot water and the tank's heat losses. The design of the storage capacity is based on three hypotheses. The coverage of hot water demand by solar energy, the ratio between storage capacity and solar thermal collector area and the prediction that the storage capacity corresponds to one- to twofold hot water demand. The purpose of this thesis is to share an understanding of the solar storage tanks design and to improve the design through numerical simulation, experimentations and general calculations. It also focuses on the confirmation of the used hypotheses and determination of the best way to design the solar storage tank for general practice and further potential discussions. The simulation model has three variables – the storage capacity, collector area and the number of occupants. The intent is to find the interdependence of these three variables. The purpose of the simulations is to modify the design of the solar tank based on the mutual influence of studied parameters. The modifications are performed based on the users' needs.
25
Cekl, Jakub. "Model palivového souboru tlakovodního reaktoru západní koncepce". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2018. http://www.nusl.cz/ntk/nusl-376896.
26
Lung, Hua-Hung, e 龍驊翃. "Computer Simulation Validated of The Innovation Micro-Gravity Algorithm". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/31872060846226104207.
Abstract (sommario):
碩士國立中央大學
光機電工程研究所
100
This thesis is to verify the innovative micro-gravity algorithm that prof. Jiang Shi Biao proposed, through the computer simulation, and developed the MEMS-type micro-gravimeter and its verification platform. In this thesis, the results of computer simulation shows the feasibility of this algorithm, provides the information of the whole system for the MEMS-type micro-gravimeter circuit design specifications, software, also reduces the volume of the gravimeter and development costs. The follow-up construction of the system verification platform, provides the MEMS-type gravimeter experiment platform.
27
Martins, Joana Maria Ferreira Alvura da Hora. "Performance Criteria to Validate Simulation Models". Master's thesis, 2012. https://repositorio-aberto.up.pt/handle/10216/66658.
28
Martins, Joana Maria Ferreira Alvura da Hora. "Performance Criteria to Validate Simulation Models". Dissertação, 2012. https://repositorio-aberto.up.pt/handle/10216/66658.
29
Benezech, Laurent Jean-Michel. "Premixed Hydrocarbon Stagnation Flames: Experiments and Simulations to Validate Combustion Chemical-Kinetic Models". Thesis, 2008. https://thesis.library.caltech.edu/2316/6/index.html.
Abstract (sommario):
A methodology based on the comparison of flame simulations relying on reacting flow models with experiment is applied to C1–C3 stagnation flames. The work reported targets the assessment and validation of the modeled reactions and reaction rates relevant to (C1–C3)-flame propagation in several detailed combustion kinetic models. A concensus does not, as yet, exist on the modeling of the reasonably well-understood oxidation of C1–C2 flames, and a better knowledge of C3 hydrocarbon combustion chemistry is required before attempting to bridge the gap between the oxidation of C1–C2 hydrocarbons and the more complex chemistry of heavier hydrocarbons in a single kinetic model.
Simultaneous measurements of velocity and CH-radical profiles were performed in atmospheric propane(C3H8)- and propylene(C3H6)-air laminar premixed stagnation flames stabilized in a jet-wall configuration. These nearly-flat flames can be modeled by one-dimensional simulations, providing a means to validate kinetic models. Experimental data for these C3 flames and similar experimental data for atmospheric methane(CH4)-, ethane(C2H6)-, and ethylene(C2H4)-air flames are compared to numerical simulations performed with a one-dimensional hydrodynamic model, a multi-component transport formulation including thermal diffusion, and different detailed-chemistry models, in order to assess the adequacy of the models employed. A novel continuation technique between kinetic models was developed and applied successfully to obtain solutions with the less-robust models. The 2005/12 and 2005/10 releases of the San Diego mechanism are found to have the best overall performance in C3H8 and C3H6 flames, and in CH4, C2H6, and C2H4 flames, respectively.
Flame position provides a good surrogate for flame speed in stagnation-flow stabilized flames. The logarithmic sensitivities of the simulated flame locations to variations in the kinetic rates are calculated via the "brute-force" method for fifteen representative flames covering the five fuels under study and the very lean, stoichiometric, and very rich burning regimes, in order to identify the most-important reactions for each flame investigated. The rates of reactions identified in this manner are compared between the different kinetic models. Several reaction-rate differences are thus identified that are likely responsible for the variance in flame-position (or flame-speed) predictions in C1–C2 flames.
30
Chun-RenZhang e 張淳仁. "Design Approach to Synthesize, Validate, and Evaluate Operating Procedures Based on Timed Automata and Dynamic Simulation". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/7upubw.
Abstract (sommario):
碩士國立成功大學
化學工程學系
107
Despite the fact that the modern chemical plants are becoming much more complex than they used to be, their operating procedures are still generated manually in most cases. Since this approach is clearly laborious, time-consuming and error prone, it is necessary to develop a viable approach to systematically and automatically conjecture a set of reliable control actions to perform various tasks in realistic chemical processes. With timed automata and dynamic simulation, the tasks of synthesizing, validating and evaluating operating procedures have been accomplished in this work. Specifically, the following steps are carried out: First of all, it is necessary to discretize all state variables in the given system and then build the untimed automata for modeling the basic components according to generic engineering knowledge. Secondly, the elapsed times of all possible state transfers for every processing unit can be determined with Aspen Plus Dynamics and the corresponding timed automata can then be built to model these units. Next, after identifying the critical stages of the entire operation, one can stipulate the control specifications of each stage and build the corresponding automata. All automata built above should then be integrated and synthesized into a system model. Consequently, the shortest or quickest trace in the system may be extracted with UPPAAL and every trace summarized with a sequential function chart (SFC). Finally, the SFCs should be verified with Aspen Plus Dynamics. If the simulation study confirms that all SFCs are unsafe and/or infeasible, one should modify/add/remove the control specifications and repeat the aforementioned synthesis steps. The above procedure has been applied successfully to three examples, i.e., the start-up operations of a continuous flash drum, a continuous distillation column and a continuous reactive distillation column.
31
LIU, TE-SHENG, e 劉得笙. "Taking the Advantage of Acceleration Response of a Geosynthetic Reinforced Slope to Validate the Seismic Numerical Simulation". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/7476b3.
Abstract (sommario):
碩士國立宜蘭大學
土木工程學系碩士班
106
The Ilan area is near the seismic zone of northeastern Taiwan, and the earthquakes are quite frequent. In order to understand the seismic behavior of the geosysthetic reinforced slope comprehensively, this study is carried out by installing seismic accelerometers at the different positions of the geosysthetic reinforced slope built in the FoGuang University. Earthquake monitoring data recorded on the site are used as validation basis for the studying dynamic responses. From the data obtained by the monitoring program, it can be recognized that the maximum acceleration of the geosynthetic reinforced slope under the action of the earthquake will be amplified with the height of the slope. The recorded seismic data will be used by the PLAXIS finite element program to simulate the seismic behavior of the geosynthetic reinforced slope. In order to understand more about the seismic wave propagation behavior inside the geosynthetic reinforced slope, this study uses the PLAXIS finite element program to perform dynamic analysis. From the results of numerical simulation, it is found that the geosynthetic reinforced slope has obvious scale-up behavior in the middle layer and the top layer. In the dynamic analysis, it often takes a lot of calculation time for numerical simulation process. In order to further understand the impact of seismic wave propagation between finite elements on geosynthetic reinforced slopes, this study tries to use different nodal elements for dynamic analysis, namely 6-node and 15-node finite elements. The 6-nodal unit effectively interprets the dynamic behavior of geosynthetic reinforced slopes with condensed computational time. In this study, we integrate the acceleration time history data of the earthquakes on the site, and convert the acceleration duration graphs monitored at different positions into acceleration response spectra. It can be seen that the same earthquake has different periodic peak changes in different position. This study analyzes the predicted results of the geosysthetic reinforced slope, and then converts the simulated earthquake acceleration duration graphs into seismic acceleration response spectrum as well. In this study, in addition to the maximum acceleration, the change of the acceleration response spectrum is studied to understand the dynamic behavior of the slope and to discuss the influence of soil parameters on the acceleration response spectrum using PLAXIS. Due to the wide variety of soil parameters affecting the results of the dynamic analysis of the FEM model, this study specifically focuses on the material damping ratio and the elastic modulus of the soil material.
32
Venâncio, Ana Cláudia Serdoura. "Self-Report Symptom Inventory (SRSI): Estudos de validação em contexto prisional (design de simulação análogo, validade convergente e validade discriminante)". Master's thesis, 2021. http://hdl.handle.net/10316/99302.
Abstract (sommario):
Dissertação de Mestrado Integrado em Psicologia apresentada à Faculdade de Psicologia e de Ciências da EducaçãoThe adoption of biased response styles, such as the simulation and exaggeration of psychopathological symptoms, by an examinee, composes a threat to the validity of the results of a (neuro)psychological assessment, especially in forensic contexts, in which secondary gains can stand out. Symptom Validity Tests (SVT) aim to detect the presence of such response styles/ behaviors, in order to provide mental health professionals more reliable interpretations of an individual's actual psychological functioning profile.This study seeked to continue the validation process of the Self-Report Symptom Inventory (SRSI; Merten et al., 2016) for the portugueses prison context. To achieve the mentioned goal, to a prison sample of 100 inmates, aged between 18 and 72 years old, was administered an assessment protocol consisting of the following instruments: the SRSI, the Structured Inventory of Malingered Symptomatology (SIMS; Smith & Burger, 1997; Widows & Smith, 2005; portuguese version: Simões, Almiro, Mota, et al., 2017), the Symptom Validity Scale – Version 2 (EVS-2; Simões, Almiro, Nunes, et al., 2017; Cunha, 2011) and the Brief Symptom Inventory (BSI; Derogatis, 1982; portuguese version: Canavarro, 2007). The present SRSI validation study was based on analogous simulation design, in an intra-subject way. Therefore, all participants answered to the SRSI in two contiguous moments: in a honest way (“honest” condition) and according to instructions (cover story – “simulation” condition) built in line with the recommendations that emerge from the scientific literature, in an attempt to maximize the possibility of generalizability of the data.Regarding the results, the reliability studies (internal consistency of the SRSI scores) indicate high values of Cronbach's alpha for both scales, in both conditions. In the context of convergent validity studies, it should be noted that the SRSI has validity with other TVS (e.g., SIMS and EVS-2), since the results showed the existence of positive, high and significant relationships between the Pseudo-symptoms scale (SRSI) and the total result of the SIMS and EVS-2 (instruments that measure similar theoretical constructs). In the same sense, and as expected, positive, moderate and/or strong correlations were observed between the Genuine Symptoms scale (SRSI) and the BSI global indices (instrument that measures the presence of genuine psychopathology). In the domain of discriminant validity, non-significant, reduced or null correlations were expected between the Pseudo-symptoms scale (SRSI) and the BSI, due to the measurement of non-overlapping constructs. Nevertheless, the results suggested that Pseudo-symptoms scale proved to be equally sensitive to the presence of psychopathology, since there were moderate and strong correlations between it and the global BSI indices – aspect that indicates lack of discriminant validity. In turn, as expected, positive but reduced correlations were observed between the total of the Genuine Symptoms scale (in the “honest” condition) and the total of the Pseudo-symptoms scale (in the “simulation” condition). Also with regard to discriminant validity, it was possible to verify the SRSI's ability to differentiate the scores of the “honest” condition and the “simulation” condition, since there were statistically significant differences between the means obtained in them, with the corresponding effect size being large. In the same sense, the SRSI proved to be able to discriminate the responses of inmates from non-inmates (control sample), scoring the former significantly more than the latter, on the scales and in most subscales of the SRSI.The implications of this study in a prison context are analyzed and recommendations for future investigations are presented.
A adoção de estilos de resposta enviesados, como a simulação e exagero de sintomas psicopatológicos, por parte de um examinando, constitui uma ameaça à validade dos resultados de uma avaliação (neuro)psicológica, especialmente em contextos forenses, nos quais ganhos secundários têm elevada probabilidade de manifestação. Os Testes de Validade de Sintomas (TVS) têm como objetivo detetar a presença de tais estilos de resposta/ comportamentos, viabilizando, desse modo, interpretações mais fidedignas acerca do perfil de funcionamento psicológico real de um indivíduo. A presente investigação procurou dar continuidade ao processo de validação do Self-Report Symptom Inventory (SRSI; Merten et al., 2016) no contexto prisional português. Para a concretização do referido objetivo, foi administrado a uma amostra prisional de 100 reclusos, com idades compreendidas entre os 18 e os 72 anos, um protocolo de avaliação constituído pelos seguintes instrumentos: o SRSI, o Structured Inventory of Malingered Symptomatology (SIMS; Smith & Burger, 1997; Widows & Smith, 2005; versão portuguesa: Simões, Almiro, Mota, et al., 2017), a Escala de Validade de Sintomas – Versão 2 (EVS-2; Simões, Almiro, Nunes, et al., 2017; Cunha, 2011) e o Brief Symptom Inventory (BSI; Derogatis, 1982; versão portuguesa: Canavarro, 2007). O presente estudo de validação do SRSI recorreu ao design de simulação análogo, numa vertente intra-sujeitos. Desta forma, todos os participantes responderam ao SRSI em dois momentos contíguos: de forma honesta (condição “honesta”) e de acordo com instruções (cover story – condição de ”simulação”), elaboradas considerando recomendações da literatura científica e orientadas para maximizar a possibilidade de generalização dos dados.No que concerne aos resultados, os estudos de fiabilidade (consistência interna das pontuações no SRSI) indicam valores elevados de alfa de Cronbach para ambas as escalas, em ambas as condições. No âmbito dos estudos de validade convergente, é de referir que o SRSI contém validade com outros TVS (e.g., SIMS e EVS-2), já que os resultados evidenciaram a existência de relações positivas, elevadas e significativas entre a escala de Pseudo-sintomas do SRSI e o resultado total do SIMS e da EVS-2 (instrumentos que medem constructos teóricos semelhantes). No mesmo sentido, e de acordo com o esperado, foram encontradas correlações positivas, moderadas e/ou fortes entre a escala de Sintomas Genuínos e os índices globais do BSI (instrumento que mede a presença de psicopatologia genuína). No domínio da validade discriminante, esperavam-se correlações não significativas, reduzidas ou nulas entre a escala Pseudo-sintomas do SRSI e o BSI, uma vez que mensuram constructos não sobrepostos. Porém, os resultados sugeriram que a escala Pseudo-sintomas se revelou igualmente sensível à presença de psicopatologia, uma vez que se observaram correlações moderadas e fortes entre a mesma e os índices globais do BSI – aspeto sinalizador de ausência de validade discriminante. Por sua vez, e de acordo com o esperado, foram observadas correlações positivas reduzidas entre o total da escala Sintomas Genuínos (na condição “honesta”) e o total da escala Pseudo-sintomas (na condição “simulação”). Ainda no que concerne à validade discriminante, foi possível verificar a capacidade do SRSI, diferenciar as pontuações da condição “honesta” e da condição “simulação”, na medida em que se observaram diferenças estatisticamente significativas entre as médias obtidas nas mesmas, sendo o tamanho de efeito correspondente grande. No mesmo sentido, o SRSI revelou ser capaz de discriminar as respostas dos participantes reclusos de participantes não-reclusos (amostra de controlo), pontuando os primeiros significativamente mais do que os segundos, nas escalas e na maioria das subescalas do SRSI.São analisadas as implicações do presente estudo em contexto prisional e apresentadas recomendações para futuras investigações.
33
Huang, Chia-Ling, e 黃佳玲. "Using Games and Simulations to Overcome Two Obstacles that Block the Introduction of CCPM to PM Society and Validate its Effectiveness". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/39345736248086803135.
Abstract (sommario):
博士國立交通大學
工業工程與管理學系
99
Since 1997, the Critical Chain Project Management method (CCPM) has received considerable attention. Hundreds of successful CCPM cases have achieved highly reliable on-time delivery (OTD) with short project lead-time (PLT) in multi-project environments. However, two obstacles have remained, blocking the introduction of CCPM to project management (PM) society. The first has been addressed by PM practitioners, who have been less than confident that OTD and PLT can be significantly improved by simply changing the way to manage multi-projects. The second is from academia: some scholars have claimed that the ideas of CCPM are not new and are of no substantial contribution to PMBOK. In this study, we first used multi-project management games to overcome the first obstacle. A comparative study of CCPM and PERT/CPM planning methods, excluding bad human behaviors, was then conducted to overcome the second obstacle. Results show that: (1) the “mode of managing multi-projects” was the root cause, and changing the mode of managing multi-project could significantly improve OTD and PLT; (2) in terms of mean project time, CCPM is not significantly better than PERT/CPM. However, in terms of plan reliability, CCPM achieves higher than PERT and CPM. This is due to a CCPM logistical change that generates a more reasonable and reliable project plan than do the PERT/CPM methods.
34
"Use of Machine Learning Algorithms to Propose a New Methodology to Conduct, Critique and Validate Urban Scale Building Energy Modeling". Master's thesis, 2017. http://hdl.handle.net/2286/R.I.45561.
Abstract (sommario):
abstract: City administrators and real-estate developers have been setting up rather aggressive energy efficiency targets. This, in turn, has led the building science research groups across the globe to focus on urban scale building performance studies and level of abstraction associated with the simulations of the same. The increasing maturity of the stakeholders towards energy efficiency and creating comfortable working environment has led researchers to develop methodologies and tools for addressing the policy driven interventions whether it’s urban level energy systems, buildings’ operational optimization or retrofit guidelines. Typically, these large-scale simulations are carried out by grouping buildings based on their design similarities i.e. standardization of the buildings. Such an approach does not necessarily lead to potential working inputs which can make decision-making effective. To address this, a novel approach is proposed in the present study.
The principle objective of this study is to propose, to define and evaluate the methodology to utilize machine learning algorithms in defining representative building archetypes for the Stock-level Building Energy Modeling (SBEM) which are based on operational parameter database. The study uses “Phoenix- climate” based CBECS-2012 survey microdata for analysis and validation.
Using the database, parameter correlations are studied to understand the relation between input parameters and the energy performance. Contrary to precedence, the study establishes that the energy performance is better explained by the non-linear models.
The non-linear behavior is explained by advanced learning algorithms. Based on these algorithms, the buildings at study are grouped into meaningful clusters. The cluster “mediod” (statistically the centroid, meaning building that can be represented as the centroid of the cluster) are established statistically to identify the level of abstraction that is acceptable for the whole building energy simulations and post that the retrofit decision-making. Further, the methodology is validated by conducting Monte-Carlo simulations on 13 key input simulation parameters. The sensitivity analysis of these 13 parameters is utilized to identify the optimum retrofits.
From the sample analysis, the envelope parameters are found to be more sensitive towards the EUI of the building and thus retrofit packages should also be directed to maximize the energy usage reduction.Dissertation/Thesis
Masters Thesis Architecture 2017
35
Almeida, Carolina Duarte de. "Estudos com design de simulação análogo em Testes de Validade de Sintomas (TVS): Uma revisão da literatura". Master's thesis, 2020. http://hdl.handle.net/10316/94483.
Abstract (sommario):
Dissertação de Mestrado Integrado em Psicologia apresentada à Faculdade de Psicologia e de Ciências da EducaçãoA área da avaliação da validade de sintomas tem assumido uma importância acrescida no domínio da avaliação psicológica. Em contextos forenses, a evidência dos ganhos secundários alcançáveis com a simulação ou exagero de sintomas psicopatológicos e a prevalência deste tipo de comportamentos por parte dos avaliados, constitui um problema relevante. Os Testes de Validade de Sintomas (TVS) têm como objetivo detetar a presença de comportamentos de simulação ou exagero de sintomas permitindo, aos profissionais de saúde metal, realizar interpretações mais fidedignas dos resultados obtidos através de uma avaliação psicológica, de forma a refletir o funcionamento psicológico real do sujeito.Neste âmbito, releva-se a importância das investigações na área, para que os clínicos consigam recorrer à utilização dos TVS com confiança nos seus resultados. Uma das mais comuns metodologias de investigação na simulação de sintomas é o design de simulação análogo, no qual são formados grupos de controlo e de simulação instruída, para estudar a identificação e controlo dos instrumentos ao comportamento referido. No entanto, esta metodologia encontra-se muito associada a críticas relativas à sua fraca validade externa, devido às diferenças existentes entre as condições experimentais e as condições da vida real, nas quais esses comportamentos podem estar presentes. Neste sentido, acresce a importância de serem respeitados certos padrões de construção metodológica nas investigações realizadas, de forma a que as conclusões retiradas sejam generalizadas com confiança. Assim, na presente dissertação, é realizada uma revisão dos estudos existentes com recurso ao design de simulação análogo, com destaque para os contextos forenses (criminal e médico-legal). Considerando o número reduzido de investigações encontradas nestes contextos, são, adicionalmente, apresentados estudos em contextos comunitários. As conclusões retiradas indicam que são, ainda, cometidos diversos erros associados ao desenvolvimento das instruções de simulação, o que coloca em risco a fiabilidade com que são interpretados os comportamentos de simulação reproduzidos pelos “simuladores experimentais”. São feitas recomendações de natureza metodológica orientadas para assegurar um maior grau de representatividade e generalização dos resultados obtidos neste design de simulação análogo para os contextos reais.
Symptom validity assessment is an area becoming increasingly important in the field of psychological assessment. In forensic contexts, the presence of evident secondary gains achievable with malingering or symptom overreporting on the part of the evaluated, and the prevalence of this kind of performance, constitutes a relevant problem. Symptom Validity Tests (SVT) aim to detect the presence of malingered symptomatology, allowing mental health professionals to produce more reliable interpretations of the results obtained through a psychological assessment, in order to reflect the subject’s real psychological functioning.Therefore, the attainment of investigations in the area is highlighted, to help clinicians to resort to the use SVT with confidence in their results. One of the most common investigation methodologies to evaluate the identification and control of malingering by the SVT, is the analogue simulation design, according to which participants are allocated to control or simulation conditions. Nevertheless, this methodology is closely associated with criticisms regarding its weak external validity, due to the differences between the experimental and real-life conditions. Thus, investigators should respect certain methodological standards, so that the conclusions drawn from the investigations are generalized with confidence.In the present dissertation, a review of the existing studies using analogue simulation design is carried out. Emphasis is placed on forensic (criminal and medico-legal) contexts, with addition of community contexts, due to the reduced number of investigations in the first ones. The conclusions drawn indicate several errors associated with the development of simulation instructions, which lays risk in the reliability with which the simulation behaviours reproduced by experimental simulators are interpreted. Methodological recommendations oriented to ensure a higher degree of representativeness and generalization of the results obtained in this analog simulation design are made.
36
Domingues, Margarida Vasconcelos. "Self-Report Symptom Inventory (SRSI): Validação através de um estudo de simulação análogo". Master's thesis, 2019. http://hdl.handle.net/10316/86698.
Abstract (sommario):
Dissertação de Mestrado Integrado em Psicologia apresentada à Faculdade de Psicologia e de Ciências da EducaçãoMalingering of symptoms is a very important research problem in forensic neuropsychological evaluation. In this context, examining the credibility of the subjects' reports led to the development of SVTs (Symptom Validity Tests), tests focused on the detection of the simulation and exaggeration of symptoms. The methodology associated with the analog simulation model is widely used in the internal validation of instruments.The current research focuses on the adaptation and validation of the Self-Report Symptom Inventory (SRSI; Merten et al., 2016) to European Portuguese using the analog simulation model. The SRSI is a self-reported symptom instrument that has two main scales of Genuine Symptoms and Pseudosymptoms where several clinical subscales are integrated. For this study, the SRSI was administered twice to a sample of 70 undergraduate students, a first time where they were instructed to respond honestly and second time where they were instructured to simulate symptoms according to a given scenario. This sample also answered to the SIMS (Structured Inventory of Malingered Symptomatology) instrument used as an external criterion for comparison and validation of the SRSI.The results obtained in the “honest” and in the “malingering” condition for the SRSI subscales and scales revealed Cronbach alphas ranging from "unacceptable" to "very good", with no present difference between the two conditions. The results demonstrated an evident increase in the report of symptoms between the “honest” condition and the “malingering” condition. Significant moderate and strong correlations were found between the subscales of Genuine Symptoms and Pseudosymptoms of the SRSI “honest” condition with the SIMS scales, as well as very strong correlations between the totals of Genuine Symptoms and Pseudosymptoms and the total score in the SIMS.In general, the results support the use of SRSI as a complementary tool to other SVTs, but they also emphasize the need for further studies integrating different samples and different research methods (e.g. subjects with real disorders and formal diagnosis).
A credibilidade dos relatos dos sujeitos e a simulação e/ou exagero de sintomas constituem problemas importantes da avaliação e da investigação neuropsicológica forense. Os Testes de Validade de Sintomas (TVS) são um tipo de instrumentos especificamente desenvolvido para a avaliação da simulação e/ou exagero de sintomas psicopatológicos. Neste contexto, o design de simulação análogo (analog simulation design) constitui uma metodologia muito utilizada na validação interna destes instrumentos.A presente investigação centra-se na validação do Self-Report Symptom Inventory (SRSI; Merten et al., 2016) para o português europeu através do modelo de simulação análogo. O SRSI é um instrumento de autorrelato de sintomas (TVS) que conta com duas escalas principais (Sintomas Genuínos e de Pseudo-Sintomas) que integram várias subescalas clínicas. Neste estudo foi utilizada uma amostra de 70 estudantes universitários a quem foi administrado o SRSI duas vezes. Na primeira aplicação, os sujeitos foram instruídos a responder de forma honesta. Na segunda administração os sujeitos foram convidados a responder de forma simulada de acordo com um cenário previamente fornecido (Cenário “Ansiedade” ou Cenário “Dores”). A referida amostra respondeu ainda ao SIMS (Structured Inventory of Malingered Symptomatology), um outro TVS já validado para a população portuguesa, aqui utilizado como critério externo de comparação e validação das pontuações no SRSI.Os resultados da consistência interna obtidos na condição “honesta” e na condição “simulação” para as subescalas e escalas do SRSI variam entre “inaceitáveis” e “muito bons” não se observando muitas diferenças entre as duas condições. De acordo com o esperado, os resultados demonstraram um incremento evidente na comunicação do número de sintomas da condição “honesta” para a condição “simulação”. Foram observadas correlações significativas moderadas e fortes entre as subescalas de Sintomas Genuínos e de Pseudo-Sintomas do SRSI condição “honesta” com as escalas do SIMS, e também correlações muito fortes entre os totais de Sintomas Genuínos e de Pseudo-Sintomas e a pontuação total no SIMS.Os resultados apoiam a utilização do SRSI como instrumento potencialmente útil a incluir nos protocolos de avaliação neuropsicológica forense, num registo complementar a outros TVS, mas sublinham igualmente a necessidade de novos estudos que integrem diferentes amostras e diferentes métodos de investigação (e.g., sujeitos com perturbações reais objeto de diagnóstico formal, examinados em contextos clínicos e forenses).
37
Pinheiro, Débora Alexandra Silva. "Self-Report Symptom Inventory (SRSI): Estudo de validação em uma amostra de reclusos". Master's thesis, 2019. http://hdl.handle.net/10316/86471.
Abstract (sommario):
Dissertação de Mestrado Integrado em Psicologia apresentada à Faculdade de Psicologia e de Ciências da EducaçãoA avaliação da simulação e exagero de sintomas é uma tarefa básica em avaliação (neuro)psicológica especialmente em contextos forenses nos quais o ganho secundário pode estar presente. A utilização de Testes de Validade de Sintomas (TVS) constitui uma metodologia recente e promissora para este mesmo fim.Este estudo consiste na validação do Self-Report Symptom Inventory (SRSI; Merten et al., 2016) para a população portuguesa em contexto forense. O SRSI é um novo instrumento destinado a avaliar a credibilidade dos sintomas relatados, constuituido não só por sintomas raros ou atípicos (Pseudo-sintomas), mas também por Sintomas Genuínos. Para tal foi recolhida uma amostra prisional de 85 sujeitos com idades compreendidas entre os 22 e os 65 anos. Para este estudo, o protocolo de avaliação incluiu para além do SRSI o Structured Inventory of Malingered Symptomatology (SIMS; Smith & Burger, 1997; Widows & Smith, 2005; versão portuguesa Simões, et al., 2017) e testes de avaliação de psicopatologias específicas como Inventário de Depressão de Beck (BDI-II; Beck, Steer & Clark, 1996; versão portuguesa validada por Oliveira-Brochado, Simões, & Paúl, 2014); Inventário de Ansiedade Estado-Traço (STAI Forma Y; Spielberger et al., 1983; validado para a população portuguesa por Silva, 2003) e o Inventário Resumido da Dor (BPI; Ferreira-Valente, Pais-Ribeiro & Jensen, 2009), com os quais foram realizados estudos de validade. Os resultados evidenciaram a existência de relações positivas e significativas entre a Escala de Pseusosintomas do SRSI e o resultado total do SIMS, instrumentos que avaliam genericamente os mesmos constructos (simulação, exagero de sintomas, respostas enviesadas negativas). O mesmo se verifica na análise das correlações entre os resultados totais dos restantes instrumentos incluídos no protocolo e a Escala e subescalas de Sintomas Genuínos do SRSI. No entanto, verificou-se que um outro estilo de resposta (a desejabilidade social) não influenciava os resultados nas Escalas e subescalas do SRSI.Explorámos ainda a existência de efeito de diversas variáveis criminais e sociodemográficas nos resultados do SRSI. Apenas foi identificado impacto significativo da variável “toma da medicação” no resultado da Escala de Pseudo-sintomas do SRSI, as restantes variáveis não apresentaram influências significativas nos resultados. Relativamente à fiabilidade, os resultados de consistência interna obtidos para o SRSI foram promissores tanto para a Escala de Sintomas Genuínos (α=.802) como para a Escala de Pseudo-sintomas (α=.806).São analisadas as implicações do presente estudo em contexto prisional e apresentadas recomendações para futuros estudos.
The evaluation of the simulation and exaggeration of symptoms is a basic task in (neuro)psychological evaluation especially in forensic contexts in which the secondary gain may be present. The use of Symptom Validity Testing (TVS) is a recent and promising methodology for this purpose.This study consists of the validation of the Self-Report Symptom Inventory (SRSI; Merten et al., 2016) for the Portuguese population in a forensic context. The SRSI is a new instrument to evaluate the credibility of the symptoms reported, not only for rare or atypical symptoms (Pseudo-sintomas), but also for Genuine Symptoms. For this purpose, a prison sample of 85 subjects between the ages of 22 and 65 was collected. For this study, the evaluation protocol included in addition to SRSI the Structured Inventory of Malingered Symptomatology (SIMS; Smith & Burger, 1997; Widows & Smith, 2005; Portuguese version Simões, et al., 2017) and evaluation tests of specific psychopathologies such as Beck Depression Inventory (BDI-II; Beck, Steer & Clark, 1996; Portuguese version validated by Oliveira-Brochado, Simões, & Paúl, 2014); State-Trait Anxiety Inventory (STAI Forma Y, Spielberger et al., 1983, validated for the Portuguese population by Silva, 2003) and the Brief Inventory of Pain (BPI; Ferreira-Valente, Pais-Ribeiro & Jensen, 2009), with which validity studies were carried out. The results evidenced the existence of positive and significant relationships between the SRSI Pseusesintomas Scale and the total SIMS result, instruments that generally evaluate the same constructs (simulation, exaggeration of symptoms, negative bias responses). The same is true in the analysis of the correlations between the total results of the other instruments included in the protocol and the SCSI Scale and subscales of Genuine Symptoms. However, it was found that another style of response (social desirability) did not influence the results in SRSI scales and subscales.We also investigated the existence of an effect of several criminal and sociodemographic variables on SRSI results. Only a significant impact of the variable "medication intake" on the SRSI Pseudosymptomatic Scale result was found, the remaining variables did not present significant influence on the results.Regarding reliability, the internal consistency results obtained for SRSI were promising for both the Genuine Symptom Scale (α = .802) and the Pseudosymptomatic Scale (α = .806).The implications of the present study in a prison context are analyzed and recommendations for future studies are presented.