Dissertations / Theses on the topic 'Testing and simulation'
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Nybacka, Mikael. "Distributed vehicle testing : dynamic simulation for automotive winter testing." Licentiate thesis, Luleå : Luleå University of Technology, 2007. http://epubl.ltu.se/1402-1757/2007/28/.
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Le, Gaux Clyde R. III. "STARE CubeSat Communications Testing, Simulation and Analysis." Thesis, Monterey, California. Naval Postgraduate School, 2012. http://hdl.handle.net/10945/17397.
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Approved for public release; distribution is unlimitedThe Space-based Telescope for the Actionable Refinement of Ephemeris (STARE) CubeSat will play an important role in contributing to this nations space situational awareness (SSA), perhaps one day becoming an integral part of the space surveillance network (SSN) to track orbital debris and satellites, both active and inactive. STARE is a pathfinder mission that is expected to show that CubeSat assets can improve the accuracy of space debris ephemeris data and help national assets avoid conjunction. However, STARE cannot do its job if it cannot communicate effectively with the ground architecture. Knowing the functionality of the on board radio is essential to knowing the capabilities and limitations of the spacecraft. STARE is designed to communicate with the Mobile CubeSat Command and Control (MC3) ground station at the Naval Postgraduate School for data collection and analysis. This thesis shows testing and results, analysis and simulation of the STARE radio and the MC3 ground stations.
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Malcolm-Smith, Susan. "Testing Revonsuo's Threat simulation theory of dreaming." Master's thesis, University of Cape Town, 2005. http://hdl.handle.net/11427/12414.
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Includes bibliographical references (leaves 74-82).Revonsuo's Threat Simulation Theory of dreaming asserts that dreaming was selected during human evolution because it has the adaptive function of providing a threat-free context in which threat perception and avoidance can be rehearsed. This study aimed to test the prediction that the threat simulation mechanism will activate differently depending on waking exposure to ecologically valid threat cues. It also compared the impact of waking threat events on dream content with that of waking positive events, as TST asserts that only threat impacts on dream content. Data was collected from three contexts: a high threat context (the Western Cape in South Africa; n=208); a medium threat context (a black southern university in the US; n=34); and a low threat context (North Wales; n=116). Questionnaires included a Most Recent Dream report, details of exposure to walking threatening and positive events, and dreams of such events.
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Du, Lifang. "A simulation study of global model testing." View electronic thesis (PDF), 2009. http://dl.uncw.edu/etd/2009-3/rp/dul/lifangdu.pdf.
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Noone, Estelle S., Kevin Parker, and Janice Swope. "DEVELOPMENT OF PC-BASED SPACECRAFT SIMULATOR FOR EOS GROUND SYSTEM TESTING." International Foundation for Telemetering, 1999. http://hdl.handle.net/10150/606810.
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International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, NevadaSpacecraft communication simulators are extremely useful for integration and testing of spacecraft control centers and supporting ground systems. To reduce development costs, a Windows NT PC-based simulation system is being developed to support testing for upcoming NASA missions. The spacecraft simulation suite of tools integrates modules within a core infrastructure and is customized to meet mission unique specifications not met by the baseline system.
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Gonen, Ofer. "Sequential multiple comparison testing for budget-limited applications." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Dec%5FGonen.pdf.
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Cedrini, Luca. "Time Sensitive Networks: analysis, testing, scheduling and simulation." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/22305/.
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The industrial automation world is an extremely complex framework,
where state-of-the-art cutting edge technologies are continuously being replaced in order to achieve the best possible performances.
The criterion guiding this change has always been the productivity. This term has, however, a broad meaning and there are many ways to improve the productivity, that go beyond the simplistic products/min ratio. One concept that has been increasingly emerging in the last years is the idea of interoperability: a flexible environment, where products of different and diverse vendors can be easily integrated togheter, would increase the productivity by simplifying the design and installation of any automatic system.
Connected to this concept of interoperability is the Industrial Internet of Things (IIoT), which is one of the main sources of the industrial innovation at the moment: the idea of a huge network connecting every computer, sensor or generic device so as to allow seamless data exchange, status updates and information passing. It is in this framework that Time Sensitive Networks are placed: it is a new, work-in-progress set of communication standards whose goal is to provide a common infrastructure where all kinds of important data for an industrial automation environment, namely deterministic and non deterministic data, can flow. This work aims to be an initial step towards the actual implementation of the above-mentioned technology. The focus will therefore be not only on the theoretical aspects, but also on a set of practical tests that have been carried out in order to evaluate the performances, the required hardware and software features, advantages and drawbacks of such an application.
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Fettig, Heiko M. "Design, simulation and testing of micromachined flexible joints." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/NQ63476.pdf.
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Whaballa, Ala. "Reservoir simulation and well testing of compartmentalized reservoirs." Thesis, Heriot-Watt University, 1991. http://hdl.handle.net/10399/1493.
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Peterson, Andrew William. "Simulation and Testing of Wave-Adaptive Modular Vessels." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/54555.
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This study provides a comprehensive performance analysis of Wave-Adaptive Modular Vessels (WAM-V) using simulations and testing data. WAM-Vs are a new class of marine technology that build upon the advantages of lightweight, low-draft, catamaran construction. Independent suspensions above the hulls isolate the passengers and equipment from the harsh sea environment. Enhanced understanding of the relationship between suspension and vehicle performance is critical for future missions of interest to the U.S. Navy.
Throughout this study, the dynamic properties of three different WAM-Vs were evaluated. A multi-body dynamics simulation was developed for the 100-ft WAM-V 'Proteus' based on an automotive 4-post shaker rig. The model was used to characterize the sensitivities of different suspension parameters and as a platform for future models. A 12-ft unmanned surface vessel (USV) was instrumented and sea trials were conducted in the San Francisco Bay. A dynamic 4-post simulation was created for the USV using displacement inputs calculated from acceleration data via a custom integration scheme. The data was used to validate the models by comparing the model outputs to sensor data from the USV.
A vertical hydrodynamics testing rig was developed to investigate the interaction between the pontoons and the water surface to improve the understanding of how hydrodynamic forces affect suspension performance. A model was created to accurately simulate the hydrodynamic forces that result from vertical pontoon motion. The model was then scaled to fit a 33-ft WAM-V prototype. The 33-ft WAM-V was instrumented and sea trials were conducted in Norfolk, VA. The WAM-V's suspension was upgraded based on the testing results. A 2-post rig was also built for evaluating the 33-ft WAM-V's dynamics. Two dynamic models were made for the 33-ft WAM-V to evaluate different suspension designs.
The results from this study have numerous impacts on the naval community and on the development of WAM-Vs. The methodology for testing and evaluation will allow for future WAM-V designs to be compared under controlled circumstances. The performance of WAM-Vs can then be compared against conventional platforms to determine their suitability for future missions. Simulation development will enable future WAM-Vs to be evaluated prior to undergoing sea trials. The hydrodynamic models become a powerful design tool that can be easily scaled and combined with the 4-post models. By providing the simulations and test data to future vessel designers, the designers will be able to intelligently evaluate numerous iterations early in the design phase, improving performance and safety.Ph. D.
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Acevedo-Hueso, Luis-Francisco. "Optical simulation and testing of an optical encoder." Thesis, Heriot-Watt University, 2015. http://hdl.handle.net/10399/2977.
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Taylor, Rick, Neal Redmond, and Jeff Balding. "Temporal, Spectral, and Spatial Treat Simulation Using a Towed Airborne Plume Simulator (TAPS)." International Foundation for Telemetering, 2009. http://hdl.handle.net/10150/606036.
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ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, NevadaEfforts are underway to develop Infrared countermeasure (IRCM) systems to defend aircraft against IR guided surface-to-air (SAM) and air-to-air (AAM) missiles. One such system is the Large Aircraft Infrared Counter Measure (LAIRCM) which employs temporal, spatial, and spectral missile warning techniques. There is no current technique however, for installed system flight testing of such countermeasures in a realistic temporal, spatial, and spectral environment. This paper is an introduction to the Towed Airborne Plume Simulator (TAPS), a system designed to address this test shortfall. The TAPS operational concept is described as well as techniques for simulating missile signatures.
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Lewsey, James Daniel. "Hypothesis testing in unbalanced experimental designs." Thesis, Glasgow Caledonian University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322213.
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Peyrow, Farzad. "Field testing of an agricultural land drainage computer model." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66172.
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Weekley, Christopher D. "Aircraft simulation validation using an instrumental variable approach." Thesis, Virginia Tech, 1992. http://hdl.handle.net/10919/41517.
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A procedure is developed which offers the potential to validate aircraft simulation models using noisy flight test measurements. The proposed validation procedure is based on the instrumental variable parameter identification method. The instrumental variable method requires a choice of "instruments." For this research, the "instruments" are chosen using the response predicted by an available simulation model. With the “instruments” chosen from the predicted response, it is shown that the parameter estimates are correlated with only the measured input noise vector. In contrast, the generally used least-squares approach is shown to be correlated with both the state and input noise vectors.
Several studies are presented to demonstrate the utility of the validation procedure. These studies include input variations and noise variations. The method is demonstrated using longitudinal and lateral/directional axis cases derived from a nonlinear simulation of a high performance fighter aircraft. The results are presented using time response comparisons, eigenvalue comparisons, and identified stability derivative comparisons. The case study results confirm that the instrumental variable method performs better than the least-squares technique when the state noise level is high and the input noise level is relatively low.Master of Science
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Vedder, Benjamin. "Testing Safety-Critical Systems using Fault Injection and Property-Based Testing." Licentiate thesis, Högskolan i Halmstad, Centrum för forskning om inbyggda system (CERES), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-28173.
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Testing software-intensive systems can be challenging, especially when safety requirements are involved. Property-Based Testing (PBT) is a software testing technique where properties about software are specified and thousands of test cases with a wide range of inputs are automatically generated based on these properties. PBT does not formally prove that the software fulfils its specification, but it is an efficient way to identify deviations from the specification. Safety-critical systems that must be able to deal with faults, without causing damage or injuries, are often tested using Fault Injection (FI) at several abstraction levels. The purpose of FI is to inject faults into a system in order to exercise and evaluate fault handling mechanisms. The aim of this thesis is to investigate how knowledge and techniques from the areas of FI and PBT can be used together to test functional and safety requirements simultaneously. We have developed a FI tool named FaultCheck that enables PBT tools to use common FI-techniques directly on source code. In order to evaluate and demonstrate our approach, we have applied our tool FaultCheck together with the commercially available PBT tool QuickCheck on a simple and on a complex system. The simple system is the AUTOSAR End-to-End (E2E) library and the complex system is a quadcopter simulator that we developed ourselves. The quadcopter simulator is based on a hardware quadcopter platform that we also developed, and the fault models that we inject into the simulator using FaultCheck are derived from the hardware quadcopter platform. We were able to efficiently apply FaultCheck together with QuickCheck on both the E2E library and the quadcopter simulator, which gives us confidence that FI together with PBT can be used to test and evaluate a wide range of simple and complex safety-critical software.This research has been funded through the PROWESS EU project (Grant agreement no: 317820), the KARYON EU project (Grant agreement no: 288195) and through EISIGS (grants from the Knowledge Foundation).
PROWESS
KARYON
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Truong, Henry. "SIMULATION FOR COMMERCIAL DRIVER LICENSE THIRD PARTY TESTER TESTING." Doctoral diss., University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3480.
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The advance of technology is thought to help ease the myriad tasks that are usually involved in operating equipment. Training and testing in modern times have been replacing with simulation technologies that mimic the actual live operations and testing. Many successful stories of flight simulation come from military fighter aircraft and commercial pilot programs. The possibilities of safety in saving lives, economic incentive in reducing the operational cost and reducing the carbon footprint via simulation makes simulation worth looking into. These considerations quickly boosted the transfer from live training operations to virtual and simulation, as were easily adopted in the history of flight training and testing. Although, there has been a lack of application, the benefits of the computer based simulation as a modeling and simulation (M&S) tool can be applied to the commercial driver license (CDL) for the trucking industry. Nevertheless, this is an uphill battle to convince CDL administrators to integrate modern technology into the CDL program instead of using the traditional daily business of manual testing. This is because the cost of trucking industry live operations is still relatively affordable; individuals and companies are reluctant to adopt the use of the modeling and simulation driving or testing system. Fortunately, cost is not the only variable to consider for the training and testing administrators and their management. There is a need to expand the use of technology to support live operations. The safety of the student, trainer, and tester should be taken into account. The availability of training or testing scenarios is also an influencing factor. Ultimately, the most important factor is driving safety on the American road. The relationship of accidents with driver license fraud has led the Federal Department of Transportation to want to reduce fraud in third-party Commercial Driver License (CDL) administration. Although it is not a perfect solution that can fix all, the utilization of simulation technologies for driving assessment could be a solution to help reduce fraud if it is applied correctly. The Department of Transportation (DOT) authorized the states independent authority to administrate the local CDL including the use of the Third-Party Tester (TPT). As a result, some criminal activities prompted the Federal investigation to recommend changes and to fund the states to take action to stay in compliance with the Federal regulation. This is the opportunity for the state CDL administrator to explore the use of M&S to support its mission. Recall, those arguments for the use of the M&S is the thought of safety in saving lives, economic incentive in reducing the operational cost, and reducing the carbon footprint via using simulation. This makes simulation a viable resource. This paper will report the research study of using the computer based testing modeling and simulation tools to replace or augment the current state examiner as means of assessing the CDL TPT proficiency in basic backing skills. This pilot study of this system has several aspects to address. The scenarios must be relevant to test the knowledge of the TPT by using closely comparable scenarios to the current manual testing method. The scenario-based simulation should incorporate randomness to provide a greater sense of reality. In addition, the reconfigurable built-in random behavior scenarios provide the administrator greater control of behaviors and allow the administrator to be able to select among the random scenarios. Finally, the paper will present the data sampling from relevant participants of the CDL TPT and methodology applied. The analysis of data presents in this research study will be valuable for the State and Federal CDL administrator to consider the pros and cons of applying or adding a computer based simulation to their current testing methodology.Ph.D.
Other
Engineering and Computer Science
Modeling and Simulation PhD
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Spinks, Stephen James. "Fault simulation for structural testing of analogue integrated circuits." Thesis, University of Hull, 1998. http://hydra.hull.ac.uk/resources/hull:8047.
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In this thesis the ANTICS analogue fault simulation software is described which provides a statistical approach to fault simulation for accurate analogue IC test evaluation. The traditional figure of fault coverage is replaced by the average probability of fault detection. This is later refined by considering the probability of fault occurrence to generate a more realistic, weighted test metric. Two techniques to reduce the fault simulation time are described, both of which show large reductions in simulation time with little loss of accuracy. The final section of the thesis presents an accurate comparison of three test techniques and an evaluation of dynamic supply current monitoring. An increase in fault detection for dynamic supply current monitoring is obtained by removing the DC component of the supply current prior to measurement.
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Hay, Neil Conway. "The simulation of random environments for structural dynamics testing." Thesis, Edinburgh Napier University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328063.
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Voutsis, Kimon. "Human motion modelling for simulation testing of GNSS equipment." Thesis, University College London (University of London), 2017. http://discovery.ucl.ac.uk/1570999/.
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Pedestrian motion-induced dynamics along the line-of-sight (LOS) between a GNSS receiver and a satellite, may disrupt the nominal operation of GNSS carrier-tracking loops, by introducing cycle slips and/or false frequency locks. In combination with other factors, e.g. multipath interference, weak signal conditions or limited availability of GNSS signals, the receiver could provide a degraded navigation solution or even lose signal lock. This thesis researches firstly how pedestrian motion affects the operation of carrier phase lock loops (PLLs), used by some GNSS receivers, and frequency lock loops (FLLs), used by all GNSS receivers; and secondly, what is the best way to model pedestrian motion in order to simulate the error effects of pedestrian motion-induced dynamics on a GNSS antenna, via a simulated GNSS carrier phase lock loop (PLL). The thesis reviews the relevant literature on human biomechanical modelling, path-finding and inertial/GNSS navigation, to design a custom pedestrian motion model (PMM). The PMM validation is supported by motion capture (MoCap) experiments using an inertial/GNSS sensor held by, or attached, on a pedestrian. The thesis also describes an implementation of simulated GNSS carrier-tracking loops (SGCTLs) in Matlab, to assess the effect of human MoCap profiles and synthetic human motion profiles (from the PMM) on the performance of the SGCTLs. The testing results suggest that GNSS antenna motion dynamics due to typical pedestrian motion can induce excessive cycle slips due to dynamics stress on the simulated PLL and FLL. Therefore, antenna dynamics should be considered when designing GNSS tracking loops and navigation algorithms for pedestrian applications to allow the GNSS receiver track human motion-induced dynamics effectively. The thesis concludes with carrier-tracking bandwidth recommendations for GNSS receiver design, based on the presented evidence. Under good signal conditions (above 40dB-Hz), the minimum recommended bandwidths for PLLs and FLLs are 15Hz and 5Hz, respectively, in order to respond effectively to the dynamic stress induced by typical pedestrian movements. Finally, the results indicate that the PMM can represent the LOS dynamics stress on the SGPLL within an acceptable tolerance. Future work encompasses the analysis of the pedestrian motion effects on real GNSS receivers.
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Louw, Nicolaas Hendrik. "Real time full circuit driving simulation system." Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/50077.
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Thesis (MScEng)--Stellenbosch Universit, 2004.ENGLISH ABSTRACT: The requirements regarding the quality of engines and vehicles have increased constantly, requiring more and more sophisticated engine testing. At the same time, there is a strong demand to reduce lead time and cost of development. For many years steady state engine testing was the norm using standard principles of power absorption. Since the mid 1980's increasing importance has been attached to the optimisation of transient engine characteristics and the simulation of dynamic real world driving situations on engine test stands. This has led to the use of bi-directional DC or AC regenerative dynamometers a practice now known as dynamic engine testing. Interfacing a computer with vehicle simulation software to an engine on a dynamic test stand and using "hardware in the loop" techniques, enables the simulation of real world driving situations in a test facility. In dynamic engine testing a distinction can be made between simulation testing and transient testing. In simulation testing the set point values are predetermined whereas in transient testing a model generates set point values in real time. Speeds and loads are calculated in real time on the basis of real time measurements. The model can be in the form of a human or driver simulation. This project involved the application of dynamic engine testing to simulating a racing application. It is termed Real Time Full Circuit Driving Simulation System due to the simulation of a race car circling a race track, controlled by a driver model and running the engine on a dynamic test bench in real time using "hardware in the loop" techniques. By measuring the simulated lap times for a certain engine configuration on the test bench in real time, it is possible to select the optimal engine set-up for every circuit. The real time nature of the simulation subjects the engine on the test bench to similar load and speed conditions as experienced by its racing counterpart in the race car yielding relevant results. The racing simulation was achieved by finding a suitable dynamic vehicle model and a three dimensional race track model, developing a control strategy, programming the software and testing the complete system on a dynamic test stand. In order to verify the simulation results it was necessary to conduct actual track testing on a representative vehicle. A professional racing driver completed three flying laps of the Killarney racing circuit in a vehicle fitted with various sensors including three axis orientation and acceleration sensors, a GPS and an engine control unit emulator for capturing engine data. This included lap time, vehicle accelerations, engine speed and manifold pressure, an indicator of driver input. The results obtained from the real time circuit simulation were compared to actual track data and the results showed good correlation. By changing the physical engine configuration in the hardware and gear ratios in the software, comparative capabilities of the system were evaluated. Again satisfactory results were obtained with the system clearly showing which configuration was best suited for a certain race track. This satisfies the modem trend of minimizing costs and development time and proved the value of the system as a suitable engineering tool for racing engine and drive train optimisation. The Real Time Full Circuit Driving Simulation System opened the door to further development in other areas of simulation. One such area is the driveability of a vehicle. By expanding the model it would be possible to evaluate previously subjective characteristics of a vehicle in a more objective manner.
AFRIKAANSE OPSOMMING: Die vereistes om die kwaliteit van enjins en voertuie te verhoog, word daagliks hoër. Meer gesofistikeerde enjintoetse word daarom vereis. Terselfdertyd is dit 'n groot uitdaging om die tydsduur en koste van ontwikkeling so laag as moontlik te hou. Gestadigde toestand enjintoetse, wat op die prinsiep van krag absorpsie werk, was vir baie jare die norm. Vanaf die middel tagtigerjare het die optimering van dinamiese enjinkarakteristieke en die simulasie van werklike bestuursituasies op enjintoetsbanke van al hoe groter belang geword. Die gevolg was die gebruik van twee rigting wisselof gelykstroomdinamometers en staan vandag bekend as dinamiese enjintoetsing. Deur 'n rekenaar met simulasiesagteware aan 'n enjin op 'n dinamiese toetsbank te koppel, word die moontlikheid geskep om enige werklike bestuursituasies van 'n voertuig te simuleer in die enjintoetsfasiliteit. Dinamiese enjintoetse kan opgedeel word in simulasietoetse en oorgangstoestandtoetse. By laasgenoemde genereer 'n "bestuurdersmodel" die beheerwaardes intyds deur te kyk na intydse metings terwyl by simulasietoetse die beheerwaardes vooraf bepaal word. Die "bestuurder" kan in die vorm van 'n persoon of rekenaarsimulasie wees. Die projek behels die toepassing van dinamiese enjintoetse vir renbaansimulasie en staan bekend as'n Intydse, Volledige Renbaansisteem weens die simulasie van 'n renmotor om 'n renbaan, onder die beheer van 'n bestuurdersmodel. Dit geskied terwyl die enjin intyds op 'n dinamiese enjintoetsbank loop en gekoppel is aan die simulasie. Deur die intydse, gesimuleerde rondtetye te analiseer, word die moontlikheid geskep om die enjinkonfigurasie te optimeer vir 'n sekere renbaan. Dit is bereik deur die keuse van 'n gepaste dinamiese voertuigmodel, 'n driedimensionele renbaanmodel, ontwikkeling van 'n beheermodel, programmering van die sagteware en integrasie van die dinamiese enjintoetsstelsel. Die simulasieresultate verkry is gestaaf deur werklike renbaantoetse. 'n Professionele renjaer het drie rondtes van die Killarney renbaan voltooi in 'n verteenwoordigende voertuig wat toegerus was met verskeie sensors o.a. drie as versnellings- en orientasiesensors, GPS en 'n enjinbeheereenheidemmuleerder vir die verkryging en stoor van enjindata. Die sensors het data versamel wat insluit rondtetyd, voertuigversnellings, enjinspoed en inlaatspruitstukdruk. Die korrelasie tussen die simulasie waardes en werklik gemete data was van hoë gehalte. Deur die fisiese enjinkonfigurasie te verander in die hardeware en ratverhoudings in die sagteware, is die vergelykbare kapasiteite van die renbaansimulasie geevalueer. Die resultate was weer bevredigend en die simulasie was in staat om die beste enjinkonfigurasie vir die renbaan uit te wys. Dit bevredig die moderne neiging om koste en ontwikkelingstyd so laag as moontlik te hou. Sodoende is bewys dat die stelsel waarde in die ingenieurswêreld het. 'n Intydse, Volledige Renbaansisteem die skep die geleentheid vir verdere ontwikkeling op verskeie terreine van simulasie. Een so 'n veld is die bestuurbaarheid van 'n voertuig. Deur die model verder te ontwikkel word die moontlikheid geskep om voorheen subjektiewe karakteristieke van 'n voertuig meer wetenskaplik te analiseer.
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Williams, Steve. "Advanced Hardware-in-the-Loop Testing Assures RF Communication System Success." International Foundation for Telemetering, 2010. http://hdl.handle.net/10150/604299.
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ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, CaliforniaRF Communication (COMMS) systems where receivers and transmitters are in motion must be proven rigorously over an array of natural RF link perturbations such as Carrier Doppler shift, Signal Doppler shift, delay, path loss and noise. These perturbations play significant roles in COMMS systems involving satellites, aircraft, UAVs, missiles, targets and ground stations. In these applications, COMMS system devices must also be tested against increasingly sophisticated intentional and unintentional interference, which must result in negligible impact on quality of service. Field testing and use of traditional test and measurement equipment will need to be substantially augmented with physics-compliant channel emulation equipment that broadens the scope, depth and coverage of such tests, while decreasing R&D and test costs and driving in quality. This paper describes dynamic link emulation driven by advanced antenna and motion modeling, detailed propagation models and link budget methods for realistic, nominal and worst-case hardware-in-the-loop test and verification.
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Wu, Weixin. "Mining constraints for Testing and Verification." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/31056.
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With the advances in VLSI and System-On-Chip (SOC) technologies, the complexity of hardware systems has increased manifold. The increasing complexity poses serious challenges to the digital hardware design. Functional verification has become one of the most expensive and time-consuming components of the current product development cycle. Today, design verification alone often surpasses 70% of the total development cost and the situation has been projected to continue to worsen. The two most widely used formal methods for design verification are Equivalence Checking and Model Checking. During the design phase, hardware goes through several stages of optimizations for area, speed, power, etc. Determining the functional correctness of the design after each optimization step by means of exhaustive simulation can be prohibitively expensive. An alternative to prove functional correctness of the optimized design is to determine the design's functional equivalence with respect to some golden model which is known to be functionally correct. Efficient techniques to perform this process is known as Equivalence Checking. Equivalence Checking requires that the implementation circuit should be functionally equivalent to the specification circuit. Complexities in Equivalence Checking can be exponential to the circuit size in the worst case.
Since Equivalence Checking of sequential circuits still remains a challenging problem, in this thesis, we first address this problem using efficient learning techniques. In contrast to the traditional learning methods, our method employs a mining algorithm to discover global constraints among several nodes efficiently in a sequential circuit. In a Boolean satisfiability (SAT) based framework for the bounded sequential equivalence checking, by taking advantage of the repeated search space, our mining algorithm is only performed on a small window size of unrolled circuit, and the mined relations could be reused subsequently. These powerful relations, when added as new constraint clauses to the original formula, help to significantly increase the deductive power for the SAT engine, thereby pruning a larger portion of the search space. Likewise, the memory required and time taken to solve these problems are alleviated.
We also propose a pseudo-functional test generation method based on effective functional constraints extraction. We use mining techniques to extract a set of multi-node functional constraints which consists of illegal states and internal signal correlation. Then the functional constraints are imposed to a ATPG tool to generate pseudo functional delay tests.Master of Science
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Shipway, Philip Howard. "Erosive wear of brittle materials and its laboratory simulation." Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282026.
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Hill, Carlo Alexander Kim. "Simulation and testing of metallic aperture arrays at terahertz frequencies." Thesis, Durham University, 2016. http://etheses.dur.ac.uk/11624/.
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Since the demonstration of Extraordinary Optical Transmission (EOT) in sub-wavelength aperture arrays, first at optical then at terahertz (THz) frequencies, the role of Surface Plasmon Polaritons (SPPs) in this phenomenon has been under investigation. By studying the interaction between THz radiation and free standing metal foils, which contain periodic arrays of apertures, this thesis explores the interaction between rectangular waveguided modes controlled by aperture dimensions and SPP modes defined by aperture periodicity. Fabrication of a free standing metal foil perforated by micron scale 5:1 aspect ratio rectangular holes with varied array spacings is performed by photolithography and electroplating. Such free standing metal foils are shown to demonstrate EOT at THz frequencies when studied by terahertz time-domain spectroscopy (THz-TDS). Results obtained by the systematic variation of aperture size and lattice spacing are presented, accompanied by finite-difference time-domain (FDTD) simulation data. The changing aperture array dimensions allow for the isolation of the different resonant modes present in the EOT phenomena. Further exploitation of the interaction between the two resonant modes is provided by altering the incident angle between the free standing metal aperture array and the THz field. The high frequency resolution provided by THz Vector Network Analyser measurements allows for small changes in transmission spectra to be observed as the resonant modes are brought into close proximity. The removal of a fixed periodic spacing between the sub-wavelength apertures perforating the metal foil removes a necessary component of SPP excitation. The design of an array of aperiodic sub wavelength apertures is presented. This array demonstrates EOT in the absence of SPPs. Furthermore, SPPs induced by the periodic x-axis aperture spacing, and controlled by THz field incidence angle, are used to extinguish the sharp transmission resonance produced by the sub-wavelength apertures. To this author’s knowledge this is the first reporting of resonant transmission extinguished by SPP excitation and manipulation.
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Vanichkobchinda, Pongtana. "Numerical simulation of the dynamic impact breakage testing of rock." Thesis, University of Nottingham, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.420378.
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Kilic, Yavuz. "Testing techniques and fault simulation for analogue CMOS integrated circuits." Thesis, University of Southampton, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390727.
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Wang, Yuemiao. "Simulation combined model-based testing method for train control systems." Thesis, University of Birmingham, 2018. http://etheses.bham.ac.uk//id/eprint/8323/.
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A Train Control System (TCS) is utilised to guard the operational safety of the trains in railway systems. Therefore, functional testing is applied to verify consistency between the TCS and specification requirements. Traditional functional testing in TCSs is mainly based on manually designed test cases, which is becoming unsuitable for testing increasingly complex TCSs. Therefore, Model-Based Testing (MBT) methods have been introduced into TCS functional testing, to improve the efficiency and coverage of TCS testing, with application difficulties. To overcome the difficulties of applying MBT methods to test TCSs, the author introduces simulation combined MBT which combines an MBT method with simulation. Modelling method and implementation method for the proposed approach were explained in detail. Two case studies were undertaken to explore the effectiveness of the testing platform developed. The testing results obtained prove that the testing platform can be utilised to implement the functional testing of TCSs. To prove that the MBT platform is effective in detecting errors in the SUT, validation and verification was undertaken, which include validation of specification requirements and verification of the MBT platform. The testing performance is proven to be better than existing MBT methods in terms of coverage and efficiency.
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Flowers, Susan Caroline. "Design of a laparoscopic simulation device for testing and training." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/92177.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (page 38).
This thesis describes the development by Caroline Flowers of two prototypes of a benchtop laparoscopy simulator that mechanically simulates access ports using outer 'tissue' samples for port insertion and an inner cavity region where ex-vivo organs can be placed and operated on using laparoscopic tools. The alpha prototype was designed for testing tools for an MIT medical device design class, while the beta prototype was designed as a low-cost and more realistic substitute to simulators currently on the market.
by Susan Caroline Flowers.
S.B.
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Gallant, Andrew. "The simulation, fabrication and testing of widely tunable micromachined capacitors." Thesis, Durham University, 2005. http://etheses.dur.ac.uk/1771/.
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Breckwoldt, William Andrew. "The Simulation and Testing of Fast Locomotion with Wheel-Legs." Case Western Reserve University School of Graduate Studies / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=case153428064749947.
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Bek, Jeremy. "Design, simulation, and testing of an electric propulsion cluster frame." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-300970.
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In general, electric propulsion offers very high efficiency but relatively low thrust. To remedy this, several ion engines can be assembled in a clustered configuration and operated in parallel. This requires the careful design of a frame to accommodate the individual propulsion systems. This frame must be modular to be used in different cluster sizes, and verify thermal and mechanical requirements to ensure the nominal operation of the thrusters. The present report aims to show the design process of such a frame, from preliminary modelling to the experimental study of a prototype. This document features an overview of the iterative design process driven by thermal simulations rendered on COMSOL Multiphysics. This process led to the conception of a 2-thruster and 4-thruster cluster frame. A lumped-parameter model of the electric propulsion system was also created to model its complex thermal behaviour. In addition, the 2-thruster frame was studied mechanically with analytical calculations and simulations of simple load cases on SolidWorks. Lastly, a prototype based on the 2-thruster frame model was assembled. The prototype was used to conduct temperature measurements while hosting two operating thrusters inside a vacuum chamber. The temperature distribution in the cluster was measured, and compared to simulation results. Thermal simulations of the 2-thruster and 4-thruster frame showed promising results, while mechanical simulations of the 2-thruster version met all requirements. Moreover, experimental results largely agreed with thermal simulations of the prototype. Finally, the lumped-element model proved instrumental in calibrating the models, with its high flexibility and quick computation time.Generellt erbjuder elektrisk framdrivning hög verkningsgrad men relativt låg dragkraft. För att avhjälpa detta kan flera jonmotorer sättas samman i en klusterkonfiguration och drivs parallellt. Detta kräver en noggrann utformning av en ram för att rymma de enskilda framdrivningssystemen. Denna ram måste vara modulär för att kunna användas i olika klusterstorlekar och verifiera termiska och mekaniska krav för att säkerställa den nominella driften av motorerna. Föreliggande rapport syftar till att visa designprocessen för en sådan ram, från preliminär modellering till experimentell studie av en prototyp. Detta dokument innehåller en översikt över den iterativa designprocessen, driven av termiska simuleringar gjorda med COMSOL Multiphysics, som ledde till uppfattningen av en 2 motorer och 4 motorer ram. En klumpelementmodell av jonmotorn skapades också för att modellera dess komplexa termiska beteende. Dessutom var den 2 motorer ram studeras mekaniskt med analytiska beräkningar och simuleringar av enkla laddafall med SolidWorks. Slutligen monterades en prototyp baserad på den 2 motorer rammodellen. Prototypen användes för att göra temperaturmätningar medan den är värd för 2 jonmotorer i en vakuumkammare. Temperaturfördelningen i klustret mättes och jämfördes med simuleringsresultat. Termiska simuleringar av den 2 motorer och 4 motorer ramen visade lovande resultat, medan mekaniska simuleringar av den 2 motorer versionen klarade alla krav. Dessutom överensstämde experimentella resultat till stor del med termiska simuleringar av prototypen. Slutligen var klumpelementmodellen mycket användbar för att kalibrera de andra modellerna med sin höga flexibilitet och snabba beräkningstid.
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Sunneborn, Gudnadottir Olga. "Testing a generic GEANT4 detector simulation using H→γγ events." Thesis, Uppsala universitet, Högenergifysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-364860.
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Bagiev, Marat. "Gyroplane handling qualities assessment using flight testing and simulation techniques." Thesis, University of Glasgow, 2005. http://theses.gla.ac.uk/30918/.
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Handling qualities are without doubt one of the primary objectives of the design of modem rotary-wing aircraft, where improved handling qualities increase mission effectiveness and flight safety, and reduce pilot workload. This dissertation provides results of an assessment of gyroplane handling qualities using flight testing and simulation techniques. Since at the time of writing, there are no direct handling qualities requirements and criteria developed for light gyroplanes anywhere in the world, objective handling qualities of the G-UNIV research gyroplane are estimated using criteria from numerous fixed and rotary wing aircraft specifications. To obtain subjective handling qualities gyroplane test manoeuvres must be designed. In this thesis inverse simulation is proposed as a preliminary tool in designing gyroplane manoeuvres. A high fidelity, individual blade/blade element coupled rotor-fuselage mathematical model of a gyroplane, GSIM is developed and successfully coupled with a generic inverse simulation algorithm GENISA to form an inverse simulation package GENISA/GSIM. Two gyroplane manoeuvres, slalom and acceleration-deceleration, are designed based on those from the Aeronautical Design Standard ADS-33E-PRF. A flight test programme for the G-UNIV research gyroplane is conducted to demonstrate the use of the designed gyroplane manoeuvres and obtain subjective handling qualities. Preliminary recommendations are proposed regarding suitability of handling qualities criteria of fixed and rotary wing aircraft. In addition, this dissertation proposes two handling qualities criteria for a light gyroplane, roll quickness and pilot attack criteria for the slalom manoeuvre.
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Heywood, James K. "AUTOMATED TESTING OF THE ADVANCED DATA ACQUISITION AND PROCESSING SYSTEM." International Foundation for Telemetering, 2001. http://hdl.handle.net/10150/606456.
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International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, NevadaSoftware and techniques are described for testing the Advanced Data Acquisition and Processing System (ADAPS), the primary flight test telemetry system used at Edwards AFB, California. The software described acts as an additional simulation capability and moves the simulation definition process into a realm where data is formed by means of a high-order language. The potential for creation of more sophisticated simulated test data is thus enabled. Extension of the techniques described in this paper to applications other than testing is discussed.
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VERHAEGHE, Jacques. "TESTING THE QUALITY OF A PCM OR PAM TELEMETRY SYSTEM." International Foundation for Telemetering, 1989. http://hdl.handle.net/10150/614495.
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International Telemetering Conference Proceedings / October 30-November 02, 1989 / Town & Country Hotel & Convention Center, San Diego, CaliforniaVerifying the quality of a PCM (or PAM) telemetry system is an important concern before any launch. A frame simulator generated test is definitely inchoate to exercise the link’s real world disturbances response behavior. It should be completed with tests involving some disturbances measurements.
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Smith, Joan M. "A business case for using modeling and simulation in developmental testing." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2001. http://handle.dtic.mil/100.2/ADA396695.
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Thesis (M.S. in Program Management) Naval Postgraduate School, June 2001.Thesis advisor(s): Boudreau, Michael ; Brown, C. David. "June 2001." Includes bibliographical references (p. 123-127). Also available in print.
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Skjølberg, Ole Georg, and Anders Hansson. "Hybrid Concrete Structures : Experimental Testing and Numerical Simulation of Structural Elements." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for konstruksjonsteknikk, 2010. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-12455.
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The Composite Sandwich Slab (CSS) studied in this report is a hybrid concrete structure with different concrete types in zones of high versus low stresses. The CSS is a combination of a precast concrete formwork and in-situ concrete, where a structural top layer is supposed to be cast at the construction site. It is intended that the precast concrete formwork would be lifted directly into position before the structural top layer is cast. The precast concrete formwork consist of a relatively thin bottom layer in reinforced normal concrete with a thicker steel fiber reinforced lightweight concrete layer above. The CSS concept is supposed to be an alternative to today’s existing slab solutions in buildings and harbor structures. The CSS concept is lighter than a traditional concrete slab, but with maintained load carrying capacity. For a typical 250mm thick slab the weight reduction would be up to 35% compared to a traditional concrete slab. The precast CSS elements are also stiffer than today’s existing precast products, which means that the number of temporary supports needed during the construction phase can be reduced or eliminated. This reduction would lead to saved time, space and money at the construction site. The lightweight concrete used in the precast formwork has an approximate density of 900kg/m2 – 1150kg/m2 with a compressive strength in the range of 15-20 MPa. The lightweight concrete is relatively new product and is therefore first studied through laboratory tests with respect to compressive strength, tensile strength and shear capacity. Since the material properties for the lightweight concrete is going to be used in numerical analyses, the first laboratory tests are analyzed numerically in order to verify that agreement can be obtained and that the material models used are valid for this specific concrete. The results indicate good agreement. A concept CSS beam is then designed, tested and analyzed both by hand and numerically in order to state the CSS capacity as a slab construction. The concept CSS beam is both tested and analyzed with and without the structural top layer, i.e. as a finished product and during construction phase respectively. The laboratory tests indicate competitive capacities for both types. Hand calculations and numerical analysis performed after the test had good correlation with respect to the capacities and displacements obtained in the laboratory when testing the concept beam. The numerical analyses are therefore valid and can be used in further analyses of the CSS concept. The numerical model used in the post analysis of the CSS has been exposed to realistic loading. Both analysis of the precast part of the CSS during construction phase and analysis of the CSS with top layer and loading according to NS 3491-1 has been performed. Material and load factors have also been taken into account. The results from these analyses are promising with respect to the CSS general capacity. Results show that it is possible to use the precast formwork without temporary supports during the construction phase for a typical concrete slab with a span of 6m.
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Liu, Fu. "Comparisons of subscoring methods in computerized adaptive testing| A simulation study." Thesis, The University of North Carolina at Greensboro, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=3745565.
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LIU, FU, Ph.D. Comparisons of Subscoring Methods in Computerized Adaptive Testing: A Simulation Study. (2015) Directed by Dr. Terry A. Ackerman. 187 pp. Given the increasing demands of subscore reports, various subscoring methods and augmentation techniques have been developed aiming to improve the subscore estimates, but few studies have been conducted to systematically compare these methods under the framework of computerized adaptive tests (CAT). This research conducts a simulation study, for the purpose of comparing five subscoring methods on score estimation under variable simulated CAT conditions. Among the five subscoring methods, the IND-UCAT scoring ignores the correlations among subtests, whereas the other four correlation-based scoring methods (SEQ-CAT, PC-MCAT, reSEQ-CAT, and AUG-CAT) capitalize on the correlation information in the scoring procedure. By manipulating the sublengths, the correlation structures, and the item selection algorithms, more comparable, pragmatic, and systematic testing scenarios are created for comparison purposes. Also, to make the best of the sources underlying the assessments, the study proposes a successive scoring procedure according to the structure of the higher-order IRT model, in which the test total score of individual examinees can be calculated after the subscore estimation procedure is conducted. Through the successive scoring procedure, the subscores and the total score of an examinee can be sequentially derived from one test. The results of the study indicate that in the low correlation structure, the original IND-CAT is suggested for subscore estimation considering the ease of implementation in practice, while the suggested total score estimation procedure is not recommended given the large divergences from the true total scores. For the mixed correlation structure with two moderate correlations and one strong correlation, the original SEQ-CAT or the combination of the SEQ-CAT item selection and the PC-MCAT scoring should be considered not only for subscore estimation but also for total score estimation. If the post-hoc estimation procedure is allowed, the original SEQ-CAT and the reSEQ-CAT scoring could be jointly conducted for the best score estimates. In the high correlation structure, the original PC-MCAT and the combination of the PC-MCAT scoring and the SEQ-CAT item selection are suggested for both the subscore estimation and the total score estimation. In terms of the post-hoc score estimation, the reSEQ-CAT scoring in conjunction with the original SEQ-CAT is strongly recommended. If the complexity of the implementation is an issue in practice, the reSEQ-CAT scoring jointly conducted with the original IND-UCAT could be considered for reasonable score estimates. Additionally, to compensate for the constrained use of item pools in PC-MCAT, the PC-MCAT with adaptively sequencing subtests (SEQ-MCAT) is proposed for future investigations. The simplifications of item and/or subtest selection criteria in a simple-structure MCAT, PC-MCAT, and SEQ-MCAT are also pointed out for the convenience of their applications in practice. Last, the limitations of the study are discussed and the directions for future studies are also provided.
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Deetlefs, Ivan Niell. "Design, simulation, manufacture and testing of a free-piston Stirling engine." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95922.
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Thesis (MEng) -- Stellenbosch University, 2014.ENGLISH ABSTRACT: The aim of this study was to design and manufacture an experimentally testable free-piston Stirling engine (FPSE), including a linear electric generator; to develop and validate a theoretical simulation model; to identify problem areas pertaining to its manufacture; and finally to assess the work undertaken, to lay out the groundwork for the future development of a 3 kWe FPSE suitable for incorporation in a solar Stirling dish power generator. A redesigned version of the Beale B- 10B demonstrator engine was manufactured to overcome design diffculties and to simplify testing. The design made use of an electric generator designed at the Department of Electrical and Electronic Engineering at Stellenbosch University. Experimental measurements included piston and displacer motions, hot side and cold side temperatures, working space pressure, electric generator output, as well as heat rejection via a water jacket. Experimental measurements were taken prior to and subsequent to the addition of the electric generator. Indicated power was calculated as 0,659 W at a frequency of 10,99 Hz prior to the addition of the electric generator. The addition of the electric generator was unsuccessful since it was not well matched with the engine. The indicated power calculated was between 0,138 W and 0,144 W for different loads on the electric generator, while the electrical output power ranged from 1,23 mWe to 1,79 mWe. The addition of the electric generator produced non-continuous motion caused by magnetic forces instead of engine pressure variations. The major manufacturing diffculty was the attachment of magnets for the electric generator, but this was overcome with the manufacture of a special assembly jig. The theoretical simulation model was a combination of a third-order and dynamic analysis. Working space values were solved by the application of the conservation of mass, momentum and energy equations for a one-dimensional discretised model of the engine, while the motion of the piston and displacer was determined by applying the equations of motion. The majority of experimental measurements were predicted more accurately when higher heat transfer coeficients were used between the working space and wall temperatures. The theoretical simulation model was used to gain insight into the effect of input parameters on engine operation. The displacer rod diameter was shown to have implications on output power and stability, while it was shown that there is a natural tendency to deliver constant output power at a near-constant frequency over a range of piston loads for an FPSE. It was also shown that the design of an FPSE is complex and that the design of all components should be done in parallel. The control of an FPSE was seen to be both a necessity and can be used to exploit the advantages of the uncoupled nature of an FPSE.
AFRIKKANSE OPSOMMING: Die doel van hierdie studie was om 'n eksperimentele toetsbare vrye-werksuier Stirling enjin te vervaardiging, wat 'n lineêre elektriese kragopwekker insluit; om 'n teoretiese simulasie model te ontwikkel en te yk; om vervaardiging probleme te identi seer; en om die ondernemende werk te assesseer om 'n fondasie te lê vir die toekomstige ontwikkeling van 'n 3 kWe vrye-werksuier Stirling enjin wat by 'n Stirling sonskottel ingelyf kan word. 'n Herontwerpte weergawe van die Beale B-10B demonstrasie enjin was vervaardig om ontwerp probleme te bowe te kom en om die toets daarvan te vereenvoudig. Die ontwerp het gebruik gemaak van 'n elektriese kragopwekker wat by die Departement Elektriese en Elektroniese Ingenieurswese aan die Universiteit van Stellenbosch ontwerp is. Eksperimentele metings het die werksuier en verplaser bewegings ingesluit, sowel as die warm kant en koue kant temperature, die werkruimte druk, die elektriese uitset van die kragopwekker, sowel as die hitteuitruiling wat met 'n water verkoelingskringloop gepaard gaan. Eksperimentele metings was geneem voor en na die byvoeging van die elektriese kragopwekker. Kraglewering was bereken op 0,659 W teen 'n frekwensie van 10,99 Hz voordat die elektriese kragopwekker bygevoeg is. Die byvoeging van die elektriese kragopwekker was onsuksesvol omdat die nie gepas was vir die enjin nie. Die kraglewering is bereken op vlakke wat gewissel het tussen 0,138 W en 0,144 W vir die verskillende belastings op die elektriese kragopwekker, terwyl die elektriese uitset gewissel het tussen 1,23 mWe en 1,79 mWe. Die byvoeging van die elektriese kragopwekker het 'n nie-aaneenlopende beweging veroorsaak weens die magnetiese kragte wat dit beinvloed het in plaas van enjindruk variasies. Die belangrikste ontwerpuitdagings was die ontwerp van 'n werksuier en verplaser wat 'n klein toleransie passing kon handhaaf om sodoende 'n seël te verseker terwyl dit aan temperatuur variasies blootgestel was. Die grootste vervaardigingsprobleem was die aanheg van magnete vir die elektriese kragopwekker, maar dit is te bowe gekom deur 'n spesiale voeg te vervaardig. Die teoretiese simulasie model was 'n kombinasie van 'n derde-orde en 'n dinamiese analise. Werkruimte waardes was opgelos deur die toepassing van die behoud van massa, momentum en energie vergelykings vir 'n een-dimensionele gediskretiseerde model van die enjin, terwyl die beweging van die werksuier en verplaser bepaal was deur die toepassing van die bewegingvergelykings. Die meerderheid van die eksperimentele metings was meer akkuraat voorspel wanneer hoër warmteoordrag koë siënte tussen die werkruimte en muurtemperature gebruik was. Die teoretiese simulasie model was gebruik om insig in terme van die e ek van invoer veranderlikes op die enjin gedrag te toon. Daar was getoon dat die verplaserstaaf diameter implikasies het op kragoplewering en stabiliteit, terwyl die natuurlike tendens van 'n vrye-werksuier Stirling enjin gewys was om 'n konstante kraguitvoer te lewer op 'n naby-konstante frekwensie oor 'n reeks werksuier laste. Daar was ook gewys dat die ontwerp van 'n vryewerksuier Stirling enjin kompleks is en dat die ontwerp van alle komponente in parallel gedoen moet word. Die beheer van 'n vrye-werksuier Stirling enjin was gewys om beide noodsaaklik te wees, sowel as gebruik kan word om die unieke voordele van 'n vrye-werksuier Stirling enjin se ongekoppelde natuur te ontgin.
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Larsson, Viktor, and L. Viktor Larsson. "Simulation and Testing of Energy Efficient Hydromechanical Drivlines for Construction Equipment." Thesis, Linköpings universitet, Fluida och mekatroniska system, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-107495.
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Increased oil prices and environmental issues have increased a need of loweringthe emissions from and the fuel consumption in heavy construction machines. Anatural solution to these issues is a lowered input power through downsizing ofthe engine. This implies a demand on higher transmission efficiency, in order tominimize the intrusion on vehicle performance. More specifically, alternatives tothe conventional torque converter found in heavier applications today, must beinvestigated. One important part of this is the task of controlling the transmissionwithout jeopardising the advantages associated with the torque converter, such asrobustness and controllability.In this thesis, an alternative transmission concept for a backhoe loader is investigated.The studied concept is referred to as a 2-mode Jarchow power-splittransmission, where a mechanical path is added to a hydrostatic transmission inorder to increase transmission efficiency. The concept is evaluated in computerbased simulations as well as in hardware-in-the-loop simulations, where a physicalhydrostatic transmission is exposed for the loads caused by the vehicle duringvarying conditions. The loads are in turn simulated according to developed modelsof the mechanical parts of the vehicle drive line.In total, the investigated concept can be used instead of the torque converterconcept, if the hydrostatic transmission is properly controlled. The results alsoshow that there is a high possibility that the combustion engine in the backhoeloader can be downsized from 64 kW to 55 kW, which would further increase thefuel savings and reduce the emissions.
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Unthank, Gary. "An investigation into logistic centre design tools." Thesis, University of Sunderland, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326329.
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Tang, Chao. "Computational models for mining online drug reviews." HKBU Institutional Repository, 2014. https://repository.hkbu.edu.hk/etd_oa/87.
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Healthcare social media is emerging in recent years with increasing attention on people’s health. Online review websites are not only diversi.ed with medicine, hospitals, or doctors but abundant in amount. To discover knowledge from these online reviews, several computational models are proposed. Online healthcare review websites are facing challenges in con.ict of interests among various healthcare stakeholders. To avoid legal complaints and better sustain under such circumstance, we propose a decoupling approach for designing healthcare review websites. Objective components such as medical condition and treatment are remained as the primary parts, as they are generic, impersonal and directly related to patients themselves. Subjective components, however, such as comments to doctors or hospitals are decoupled as secondary parts for sensitive and controversial information and are optional to reviewers. Our proposed approach shows better .exibility in managing of contents in different levels of details and ability of balancing the right of expression of reviewers with other stakeholders. To identity the patient-reported adverse reactions in drug reviews, we propose a consumer-oriented coding scheme using wordnet synonym and derivational related form. Signi.cant discrepancy of incidences of adverse reactions is discovered between online reviews and clinical trials. We proposed an adverse reaction report ratio model for integrated interpretation of adverse reactions reported in online reviews versus those from clinical trial. Our estimation on average adverse reactions shows high correlation with drug acceptability score obtained from a large-scale meta-analysis. To investigate the impact of key adverse reactions in patients’ perspective, we propose a topic model named Fisher’s Linear Discriminant Analysis Projected Nonnegative Matrix Factorization (FLDA-projected-NMF) for discovering discriminative features and topics with additional class information. With satisfaction scores provided in the reviews, discriminative features and topics on satisfaction are discovered and polarities of adverse reactions are estimated based on the discriminative feature weights. Discriminative features and topics on medication duration and on age group are obtained as well. Our method outperforms other supervised methods in evaluation of topic sentiment score and topic interpretation measured by entropy. Patient-reported adverse reaction terms are mined from reviews with comment class label. Some new adverse reactions in depression drug and statin drug are also discovered. To further study patients’ behaviors, we use structural equation modeling for studying the relationship of factors in patients’ treatment experience with patients’ quality of life. In covariance model, most adverse reactions are found of small covariance except nausea, headache and dizziness. In measurement model, coef.cients of individual adverse reactions on latent adverse reaction are correlated to the incidence of adverse reactions. In structural model, we model the relationship of latent adverse reaction, rating score, positive sentiment and negative sentiment. Comparison between the measurement models of rating scores of depression drug and statin drug shows that there could be latent factors to account for the variances of latent rating, which shows correlations with the severity of adverse reactions.
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Qiu, Wangqi. "Fault simulation and test generation for small delay faults." Texas A&M University, 2006. http://hdl.handle.net/1969.1/4966.
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Delay faults are an increasingly important test challenge. Traditional delay fault
models are incomplete in that they model only a subset of delay defect behaviors. To
solve this problem, a more realistic delay fault model has been developed which models
delay faults caused by the combination of spot defects and parametric process variation.
According to the new model, a realistic delay fault coverage metric has been developed.
Traditional path delay fault coverage metrics result in unrealistically low fault coverage,
and the real test quality is not reflected. The new metric uses a statistical approach and the
simulation based fault coverage is consistent with silicon data. Fast simulation algorithms
are also included in this dissertation.
The new metric suggests that testing the K longest paths per gate (KLPG) has high
detection probability for small delay faults under process variation. In this dissertation, a
novel automatic test pattern generation (ATPG) methodology to find the K longest
testable paths through each gate for both combinational and sequential circuits is
presented. Many techniques are used to reduce search space and CPU time significantly.
Experimental results show that this methodology is efficient and able to handle circuits with an exponential number of paths, such as ISCAS85 benchmark circuit c6288.
The ATPG methodology has been implemented on industrial designs. Speed binning
has been done on many devices and silicon data has shown significant benefit of the
KLPG test, compared to several traditional delay test approaches.
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Hou, Junwei. "Concurrent fault simulation for mixed-signal circuits." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/15735.
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Schrock, Ken, Todd Freestone, and Leon Bell. "GPS RECEIVER SELECTION AND TESTING FOR LAUNCH AND ORBITAL VEHICLES." International Foundation for Telemetering, 2000. http://hdl.handle.net/10150/608283.
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International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, CaliforniaNASA Marshall Space Flight Center’s Bantam Robust Guidance Navigation & Control Project is investigating off the shelf navigation sensors that may be inexpensively combined into Kalman filters specifically tuned for launch and orbital vehicles. For this purpose, Marshall has purchased several GPS receivers and is evaluating them for these applications. The paper will discuss the receiver selection criteria and the test equipment used for evaluation. An overview of the analysis will be presented including the evaluation used to determine their success or failure. It will conclude with goals of the program and a recommendation for all GPS users.
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van, Der Westhuizen Dean. "Construct validity testing of a low cost vitreoretinal surgical simulator." Master's thesis, Faculty of Health Sciences, 2021. http://hdl.handle.net/11427/33090.
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Objective: To test the construct validity of a low cost, low fidelity vitreoretinal surgical simulator Design: Construct validity study. Six microsurgical dexterity tasks, performed on a low cost vitreoretinal surgical simulator, were graded using a scoring rubric designed to assess microsurgical dexterity. Tasks one and two were dominant hand exercises, tasks three-five required bimanual dexterity and task six assessed visualization through a retinal viewing system The scores of a novice group (Ophthalmology residents who had never performed a pars planar vitrectomy) were compared to an expert group (Vitreoretinal surgeons who had performed in excess of 20 pars planar vitrectomies). Scores were graded via video recordings of the tasks, by blinded independent graders using a scoring rubric. Participants: The novice group of surgeons included 8 ophthalmology residents training at the Groote Schuur hospital department of Ophthalmology. The expert group of surgeons included 5 vitreoretinal surgeons working at the Groote Schuur hospital department of Ophthalmology, and 2 vitreoretinal surgeons working in the private sector in Cape Town, South Africa. Results: Expert surgeons performed significantly better( P=< 0.05) than the novice surgeons across all six microsurgical dexterity tasks. Greater differences were seen in bimanual tasks(tasks three-five) and in task six that was designed specifically to assess the surgeon's ability to ensure good visualisation through a retinal viewing system. Conclusions: The microsurgical dexterity tasks performed on This low cost, low-fidelity vitreoretinal surgical simulator can distinguish between novice and expert retinal surgeons demonstrating significant construct validity. Its use can be encouraged in the training of novice vitreoretinal surgeons.
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Sawyers, William Alan. "Performance testing for the Marine Air Ground Task Force Tactical Warfare Simulation." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1995. http://handle.dtic.mil/100.2/ADA304338.
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Choi, Seong Yeon. "Stochastic modeling in fault testing of decomposable sequential circuits through computer simulation." Thesis, University of Ottawa (Canada), 1992. http://hdl.handle.net/10393/7621.
Full textAbstract:
The increasing complexity of today's digital devices has rendered the problem of fault detection, fault analysis, and test generation extremely difficult. Test generation for sequential circuits has been a difficult task. This is due to the large search space to be considered in test pattern generation. Different approaches have been taken in the past to solve the problem of fault detection and test generation in sequential circuits. A popular approach, called the scan design, is often used where the test generation problem in sequential circuits is transformed into one of combinational circuits. Unfortunately, this approach is mostly restricted to synchronous sequential circuits free of critical races. Moreover, when a circuit is very large and complex, the test generation can be quite involved, making the ad hoc approaches ineffective. Therefore, alternative methods should be considered. In this thesis, the detection of permanent faults in sequential circuits by random testing is analyzed utilizing the circuit partitioning approach together with a continuous parameter Markov model. Given a large decomposable sequential circuit, it is partitioned into several smaller partitions using either serial or parallel decomposition. For each partition with certain stuck faults specified, the original state table and its error version are derived from an analysis of the partition under fault-free and faulty conditions, respectively. Then by simulation of these two tables on a computer, the parameters of the desired Markov model are obtained. For a specified degree of confidence, it is easy to derive the parameters of the Markov model and to calculate the required lengths of random test patterns.
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Mastbergen, Daniel Blair. "Simulation and Testing of Resin Infusion Manufacturing Processes for Large Composite Structures." Thesis, Montana State University, 2004. http://etd.lib.montana.edu/etd/2004/mastbergen/MastbergenD0805.pdf.
Full textAbstract:
The use of composite materials in large primary structures such as wind turbine blades and boat hulls has dramatically increased in recent years. As these structures get larger, new manufacturing processes are required to make them possible. Larger parts also require more expensive tooling, and a higher cost for scrapped parts. This may prohibit the trial and error approach that has been used for many years. The need for accurate process modeling in the design of tooling is becoming essential. Unfortunately, as the processes become more complex so do the models. Although there are several potential processes capable of producing very large parts (10 m - 50 m), they all have one common feature. In order to alleviate the problem of forcing the resin to flow large distances though the fabric, they use a distribution system to spread the resin over the surface of the part. The resin then flows a substantially shorter distance between the channels or through the thickness. The goal of this work was to develop a modeling technique that could accurately model these processes, yet not so complex as to loose its utility. In this study, the flows through the different regions of the mold are examined individually. These regions include the injection system, the distribution channel, and the fabric. The governing equations for each region are then combined to form a comprehensive model that accounts for the flow through each region simultaneously. A series of tests were conducted to verify the models of the individual components, as well as the comprehensive model. The rate limiting step through the fabric was also examined in detail. The model correlated well with the experiments performed, and revealed critical information about these types of processes. A major conclusion is that an accurate and straightforward model can be created for large scale processes, using the small scale bench tests performed in this study. Also, the governing equations developed here from Darcy flow and Stokes flow aid in understanding how the scaling of key parameters affects the process as a whole. Variations in the geometry of the channel, the fabric thickness and fabric properties such as permeability and compressibility can be accounted for in the model.