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1
Sasson, Jonathan. "Small Scale Mass Flow Plug Calibration." Case Western Reserve University School of Graduate Studies / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=case1417540797.
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Seierstad, Johanne. "Design system for primary calibration of flow." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for energi- og prosessteknikk, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-23595.
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Whilst growing demand for energy in Nepal and neighbouring- countries, investments in hydro- power projects appears continuously, both by local and multinational companies. As a consequence of this, Turbine Testing Lab was founded in 2011 at Kathmandu University in Nepal. The laboratory is rapidly developing, and is currently implementing a Francis turbine test rig. A long- term goal for the laboratory, is to execute model tests according to IEC 60193, which is the standard used in model tests of hydraulic runners.When determining the hydraulic efficiency of a runner, a central parameter is the discharge measurement. According to IEC, any secondary device used to measure the discharge shall be calibrated in sitù against one of the following primary methods: the weighing method, volumetric method or the moving- screen method.The aim of this work has been to develop and design a primary method for calibration of the flowmeter at TTL. Based on an evaluation of the mentioned primary methods, as well as economy, accuracy and correspondence with technical staff, a volumetric method is chosen as calibration principle. The principle of the method is based on collecting water into a tank with a known geometry, and by execution of level- and time measurements calculating the discharge.The calibration rig consists of a flowmeter, inlet nozzle, deflector mechanism, emergency weir, calibration tank, level measurement, time measurement, drainage system, emergency weir, and an upgraded pipe run at the measuring section of the flowmeter.It is developed a LabView program, for logging and processing the voltage output from the flowmeter. The other measurements executed is registered manually in a separate calibration sheet for data processing. An evaluation of the accuracy in the calibration method is conducted, which may be used to determine the total uncertainty when the calibration facility is installed. Provided design and installation according to ISO 8316, the accuracy in discharge measurement with the volumetric method lies within $\pm$ 0,1- 0,2 \%. The major uncertainty contribution in the method lies in the determination of the volume collected, and the corresponding tank calibration.It is proposed to reduce the diameter of the flowmeter from original size of 400 mm to 250 mm. Reduction in diameter and upgraded pipe run will increase accuracy of the flow measurement, a result of improved flow pattern at the measuring section. When the primary calibration rig is installed at TTL, this will be a large step towards an IEC- approved laboratory in Nepal, which open doors against an international market.
3
McBrayer, Mickey Charles. "Calibration of groundwater flow models for modeling and teaching /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
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4
Blazer, Derek Jason. "Systematic method for steady-state groundwater flow model calibration." Thesis, The University of Arizona, 1999. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_etd_hy0189_sip1_w.pdf&type=application/pdf.
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Maclaurin, Paul. "Flow injection and multivariate calibration techniques for process analysis." Thesis, University of Plymouth, 1993. http://hdl.handle.net/10026.1/2056.
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The role of process analytical chemistry is summarised in chapter one with particular emphasis on a multidisciplinary approach and the instrumental requirements for on-plant analysis. These concepts are extended to process FIA, highlighting its potential for simultaneous multicomponent determinations. The development of an automated FIA monitor for the on-line determination of sulphite in potassium chloride brine is covered in the second chapter. Reaction stability is demonstrated and the results of on-plant validation and on-line trials are presented. The next chapter deals with the concepts of multivariate calibration. Direct multicomponent analysis, principal components regression and partial least squares regression are critically examined in practical spectroscopic terms and statistical terms. The relative predictive abilities of these techniques are compared in chapter four for the resolution of a multicomponent UV-visible spectrophotometric data set. Chapter five describes the development of an automated FIA-diode array system for the simultaneous determination of phosphate and chlorine. The implications of combining reaction chemistries and the influence of a number of calibration parameters are considered in detail. Finally, the jackknife is presented as a means of dimensionality estimation' and bias correction in PLS modelling. Data sets from the literature are analysed and the results compared with those obtaining using commercial software.
6
Sipahi, Sabri Ozgur. "Calibration Of A Grate On Sloping Channel." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607889/index.pdf.
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In this study a setup is designed and constructed in the Hydromechanics Laboratory of Middle East Technical University in order to observe the flow through grate inlets under different flow and geometry conditions. The rate of interception of flow is determined over a rectangular channel through preliminary experiments run on the tilting flume. The performance of the new set setup has been examined and grate efficiency is obtained both in terms of longitudinal slope and the Froude number. The results which are obtained show that the setup can be used to conduct experiments to obtain a general expression for grate efficiency.
7
Fitzmaurice, Thomas Martin, and Thomas Martin Fitzmaurice. "Calibration studies on a dual porosity unsaturated flow code (DCM3D)." Thesis, The University of Arizona, 1994. http://hdl.handle.net/10150/626906.
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A dual continuum, three-dimensional, isothermal ground-water flow code for
unsaturated, fractured, porous media (DCM3D) was calibrated against two test cases;
a laboratory block study and data from a monitored field location at the Apache Leap
Research Site. Variably saturated water flow in the matrix as well as in the fracture
system are described with two separate Richards' equation. Flow between the
respective continua is simulated by means of a first order rate equation. Relative
permeabilities are calculated using the van Genuchten characteristic relation. The
formulation leads to a coupled system of nonlinear partial differential equations which
are solved numerically using an integrated finite difference technique. Model
calibrations were developed from existing data and supplemented with estimates of
parameters not supported by previous research. Estimates included; initial conditions,
fracture porosity, fracture van Genuchten parameters (a, m and Or) and the transfer
factor. DCM3D proved able to reproduce flow behavior from both test cases.
However, given the degrees of freedom, a unique solution was not found. Therefore,
an evaluation on the conceptual understanding of flow in each test case was not
possible. Sensitivity runs on fracture parameters showed fracture saturated intrinsic
permeability and fracture porosity to be the most sensitive parameters relating to
travel time. Increases in model complexity dramatically increased run times.
Parameters which had the greatest effect on run time where the fracture a and
fracture (}r.
8
Trasky, Trevor Ryan. "Hydraulic model calibration for the Girdwood, Alaska water distribution system." Thesis, Montana State University, 2008. http://etd.lib.montana.edu/etd/2008/trasky/TraskyT0508.pdf.
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The possible EPA promulgation of regulations requiring flushing programs for water distribution systems to regulate water age is encouraging many utilities to develop a better understanding of their systems. This usually involves the development of a hydraulic model. For the hydraulic model to be of use it must be calibrated using collected field data. Few established guidelines exist for utilities to perform such data collection and calibration. There are many different types of data that can be collected using many different methods. There are also various model calibration methods that can be used. This study sought to develop an optimized sampling plan and calibration method for a small utility that defines the best practice for data type, location, quantity, and collection conditions. A large quantity of many data types were collected at various locations in the system. Different methods were used to calibrate the model with various data sets and the model accuracy was evaluated using a second independent data set. The effect of model input parameter accuracy and pipe grouping during calibration on overall accuracy was also investigated. Data type, location, quantity, and collection conditions had an impact on calibration accuracy. High headloss data from fire flow tests provided better calibrations than low loss data from static pressures. Carefully selected test locations resulted in more efficient calibration than evenly distributed test locations. There was found to be a point of diminishing returns when investigating the amount of data used in calibration versus calibration accuracy. Uncalibrated model input parameters such as elevations and pump characteristics also had a significant impact on model calibration accuracy.
9
Turley, Carole. "Calibration Procedure for a Microscopic Traffic Simulation Model." Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd1747.pdf.
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White, Jeremy. "Application of residual mapping calibration to a transient groundwater flow model." [Tampa, Fla.] : University of South Florida, 2005. http://purl.fcla.edu/fcla/etd/SFE0001314.
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Elbadramany, Iman K. "Towards calibration of optical flow of crowd videos using observed trajectories." Master's thesis, University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4889.
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The Particle Image Velocimetry optical flow algorithm had better correspondence with the velocity vectors of manually tracked crowd members than results obtained using the Lukas-Kanade method. Here, also, it was found that 40x40 pixel cells were better than 15x15. A second attempt at quantifying the correlation between optical flow and actual crowd member velocities was studied using simulations. Two processes were researched, which utilized geometrical correction of the perspective distortion of the crowd videos. One process geometrically corrects the video, and then obtains optical flow data. The other obtains optical flow data from video, and then geometrically corrects the data. The results indicate that the first process worked better. Correlation was calculated between sets of data obtained from the average of twenty frames. This was found to be higher than calculating correlations between the velocities of cells in each pair of frames. An experiment was carried out to predict crowd tracks using optical flow and a calculated parameter, beta, seems to give promising results.; The need exists for finding a quantitative method for validating crowd simulations. One approach is to use optical flow of videos of real crowds to obtain velocities that can be used for comparison to simulations. Optical flow, in turn, needs to be calibrated to be useful. It is essential to show that optical flow velocities obtained from crowd videos can be mapped into the spatially averaged velocities of the observed trajectories of crowd members, and to quantify the extent of the correlation of the results. This research investigates methods to uncover the best conditions for a good correlation between optical flow and the average motion of individuals in crowd videos, with the aim that this will help in the quantitative validation of simulations. The first approach was to use a simple linear proportionality relation, with a single coefficient, alpha, between velocity vector of the optical flow and observed velocity of crowd members in a video or simulation. Since there are many variables that affect alpha, an attempt was made to find the best possible conditions for determining alpha, by varying experimental and optical flow settings. The measure of a good alpha was chosen to be that alpha does not vary excessively over a number of video frames. Best conditions of low coefficient of variation of alpha using the Lucas-Kanade optical flow algorithm were found to be when a larger aperture of 15x15 pixels was used, combined with a smaller threshold. Adequate results were found at cell size 40x40 pixels; the improvement in detecting details when smaller cells are used did not reduce the variability of alpha, and required much more computing power. Reduction in variability of alpha can be obtained by spreading the tracked location of a crowd member from a pixel into a rectangle.ID: 030423090; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (M.S.)--University of Central Florida, 2011.; Includes bibliographical references (p. 104-108).
M.S.
Masters
Sciences
Modeling and Simulation
12
Zucchelli, Marco. "Optical Flow Based Structure from Motion." Doctoral thesis, KTH, Numerical Analysis and Computer Science, NADA, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3377.
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Wong, Wai-tak. "Calibration of new sheared delay formulae for the estimation of queues and delays in TRANSYT /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21841482.
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ARANTES, WALACE FERREIRA DE. "METROLOGICAL EVALUATION OF THE INTERLABORATORIAL COMPARISON OF THE ULTRASONIC FLOW METER CALIBRATION." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2006. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=9970@1.
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O presente trabalho refere-se à avaliação metrológica de
um mesmo medidor
ultra-sônico de vazão de líquido pelo método de tempo de
trânsito, quando
instalado em dois sistemas distintos de calibração,
pertencentes, respectivamente,
a dois laboratórios acreditados, ambos operando em
conformidade com as
especificações técnicas de instalação do fabricante e
segundo os requisitos
mínimos especificados em normas e recomendações
internacionais. A pesquisa
investigou o efeito na calibração introduzido por uma
válvula e uma curva longa
de 90° instaladas imediatamente à montante do trecho reto
de medição, que tem o
seu comprimento atendendo as condições mínimas
especificadas nas normas
aplicáveis. Concluiu-se pela necessidade de se utilizar
pelo menos 40 diâmetros
nominais (40 DN) de comprimento de trecho reto, para que a
influência da
presença da válvula e da curva longa possa ser considerada
desprezível. O
desenvolvimento do presente trabalho foi motivado pela
crescente aplicação de
medidores ultra-sônicos de vazão na indústria de petróleo
e pela urgente
necessidade de se contribuir para o avanço do conhecimento
desta tecnologia e da
normalização aplicável. Nesse sentido, o presente trabalho
contribui:
(i) para o melhor entendimento da tecnologia de medição e
do processo de
calibração de medidores ultra-sônicos de vazão de líquidos;
(ii) para o avanço da normalização no setor, uma vez que
inclui uma análise
crítica de requisitos mínimos normalizados;
(iii) para aprimoramento dos critérios de acreditação de
laboratórios que realizam
a calibração de medidores de vazão, já que avaliou desvios
de calibração
ocorridos em distintas instalações em conformidade com as
normas aplicáveis.This work deals with the metrological evaluation of the same ultrasonic flow meter by the transit time method, when installed in two different calibrating systems, belonging, respectively, to two accredited laboratories, both operating according to the manufacture´s installation technical specification, and following the minimum requirements, as specified in international standards and recommendations. The research investigated the effect in calibration due to the installation of a valve and a long 90° curve, immediately upstream of the measurement test section, with its length dimensioned according to the minimum requirements of the applicable standards. It was concluded that a longer straight sections (at least 40 diameters) should be specified, so that the influence of the installation of the valve and the curve could be neglected. The development of the present work was motivated by the growing utilization of ultrasonic flow meters by the oil industry, and by the urgent need to contribute to the advance of the technology and the applicable standardization. In this aspect, this work contributes to: (i) a better understanding of the measurement technology and of the procedure of ultrasonic liquids flow meters; (ii) the advance of the technology standardization, since it includes a critical analysis of the minimum requirements, as specified by the standards; (iii) improving the laboratory accreditation criteria for flow meter calibration, because the influence of the installation in the calibration was experimentally shown.
15
Sam, Mpaballeng Catherine. "Calibration of sap flow techniques in citrus using the stem perfusion method." Diss., University of Pretoria, 2016. http://hdl.handle.net/2263/60855.
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The aim of this study was to calibrate and decide on the most appropriate sap flow technique for citrus species in the laboratory by pushing water through cut branches. Various sap flux density techniques, including heat pulse techniques (heat ratio and compensation heat pulse methods) and the heat dissipation technique were calibrated in four citrus species, namely Citrus sinensis (Oranges), Citrus reticulata (Soft citrus), Citrus paradise (Grapefruit) and Citrus limon (Lemons). Sap flux density, determined by these three techniques, was compared to that determined gravimetrically, which was calculated as the rate of change in the mass of water passing through the stem segment divided by the area of conducting wood. Results showed that the sap flux density was consistently underestimated by all techniques and across all citrus species/varieties. However, fairly good correlations (R2>0.7) between sap flux densities determined by a sap flow technique and gravimetric determinations were found for all techniques in some stems. Despite the good correlations found in the study, a single calibration factor for each technique could not be found for citrus using the stem perfusion method. Calibration factors were determined as the inverse of the slope of the linear relationship between sap flux density determined with a sap flow technique and that determined gravimetrically. These correction factors varied between citrus species and even within stems of the same species.
Vessel dimensions (lumen diameter) and distance between groups of xylem vessels in citrus species was determined in order to try and explain the underestimation of sap flux density and the large variations in the calibration factors obtained during the calibration of the various sap flow techniques. The results revealed that the variation and underestimation were caused by contact of the probes with inactive xylem and due to differences in the nature of sapwood. The xylem vessels were unevenly distributed throughout the sapwood with large distance between the vessels, meaning that the sapwood of the studied species was considered inhomogeneous and therefore departed from the idealised theory of heat pulse measurements. The theory needs to be adapted to account for such sapwood and because of the large variation in the sapwood properties between different citrus species, calibration of these techniques is probably necessary for each new species and orchard in which measurements are to be made. Our analysis of the performance of sap flow techniques showed that the HR method should perhaps be considered before the CHP and TD methods.Dissertation (MSc (Agric))--University of Pretoria, 2016.
Plant Production and Soil Science
MSc (Agric)
Unrestricted
16
Pleiman, Brock Joseph. "Calibration of a Flow Angularity Probe with a Real-Time Pressure Sensor." University of Dayton / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1568119292467936.
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Mazur, Zachary Thomas Lyn. "Calibration and Baseline Flow Surveys of a Reconstructed Boundary-Layer Wind Tunnel." Youngstown State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1597422848793191.
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Wells, Ian. "Flow injection, vibrational spectroscopy and multivariate calibration techniques for on-line process monitoring." Thesis, University of Plymouth, 1996. http://hdl.handle.net/10026.1/1877.
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The fundamental concepts of process analytical chemistry are presented in Chapter One, which also discusses the different approaches and advantages of performing process analysis in-situ. The principles and instrumentation of flow injection analysis are presented with particular emphasis on multi-detemiinations and process applications. Flow injection analysis with Fourier transform infrared detection is proposed as a potential on-line monitoring technique highlighting its ability for simultaneous multi-analyte determinations. The principles of chemometric data analysis are summarised in Chapter Two along with the systematic approach to data analysts used in this thesis. Algorithms for experimental design, data pre-processing, exploratory data analysis (RCA) and multivariate calibration (PGR and PLS1) are described. Chapter Three describes the development and optimisation of an automated flow injection manifold coupled with a Fourier transform infrared detector for the determination of toluene, ethyl benzene and o-xylene in an n-hexane matrix by univariate calibration. In addition, Fourier transform infrared spectra are acquired of experimentally designed synthetic mixtures of the above analytes using the automated Fl manifold, and the multivariate calibration algorithms PGR, PLS1 and PLS2 are employed to quantify individual species. A critical evaluation of spectral preprocessing algorithms is reported. The following chapter describes the development of an automated internally coupled valve flow injection manifold, with Fourier transform infrared detection, for the determination of sucrose in aqueous matrices. Chapter Four describes the optimisation of the data acquisition system and reports on the critical comparison of univariate and multivariate calibration approaches, and results are presented for the determination of sucrose in commercially available fruit juices. The on-line monitoring of the synthesis of sodium glycinate in water using Fourier transform detection is described in Chapter Five. Fourier transform infrared spectral analysis of the reaction using continuous flow analysis with real time Gram Schmidt data analysis is compared to the results acquired via an automated flow injection manifold. The use of a simplex designed calibration set to mimic spectral changes in the reaction mixture to facilitate multivariate calibration is also presented. Chapter Six compares the analytical performance of a thermostabilised attenuated total reflectance flow cell with a water cooled mid-infrared fibre optic probe. Univariate and multivariate calibration algorithms are used to process reaction data sets along with gas chromatographic reference data. A detailed discussion of proposed approaches to reduce analysis time and increase information in reaction development programs is presented. The thesis concludes with an investigation of the quantitative nature of Raman spectroscopy. Experimentally designed calibration sets containing aqueous herbicide formulation samples are analysed in glass vials, with a critical evaluation of long term instrumental stability measured in terms of reproducibility and repeatability. The effects of pre-processing Raman spectral data sets, in the absence of sample matrix signals, using nonmalisation and multiple scatter correction are discussed.
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FERREIRA, GABRIEL APOLINÁRIO ALEXANDRE. "METROLOGICAL CHARACTERIZATION OF A CLAMP-ON METER FOR IN SITU CALIBRATION OF FLOW METER OPERATING UNDER DEVELOPING FLOW CONDITIONS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2015. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=26891@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROMedidores do tipo clamp-on, com trajetória ultrassônica única, são muito sensíveis ao perfil de velocidade do escoamento para medição de vazão e devem ser utilizados, para maior confiabilidade metrológica, quando o escoamento está completamente desenvolvido. Esta não é a condição normal de utilização em plataformas de petróleo, onde pequenos trechos retos estão normalmente disponíveis. Estudos numérico e experimental comprovaram que para trajetórias ultrassônicas simétricas, a média aritmética dos valores indicados pelo medidor de vazão praticamente independe dos componentes não-axiais de velocidade do escoamento em desenvolvimento em trechos retos com comprimento superior a dez diâmetros da tubulação. A trajetória única foi assegurada por meio de um dispositivo mecânico introduzido que posiciona o plano dos sensores em ângulos de 45 graus em relação à horizontal, assim permitindo medições em outras trajetórias ultrassônicas, procedimento que mostrou minimizar a incerteza associada à medição de vazão. A caracterização metrológica deste procedimento de medição, qualifica o medidor para ser utilizado como padrão itinerante em calibração in situ de medidores de vazão, o que evita a sua retirada para calibração em laboratório. A metodologia alternativa de calibração proposta foi validada experimentalmente em loop especiamente construido na PUC-Rio para reproduzir as condições de medição em campo.
Clamp-on type flow meters, with one single ultrasonic path, are very sensitive to the velocity profile in flow rate measurement and must be used, for greater metrological realiability, when the flow is completely developed. This is not the normal condition of use on oil production platforms, where small straight pipelines are usually available. Numerical and experimental studies have shown that for symmetric ultrasonic paths, the arithmetic mean of the values indicated by the flow meter is practically independent of non-axial velocity components in developing flows in straight pipeline equivalent lengths larger than ten pipeline diameters. The single path was secured by means of an introduced mechanical device that positions the sensor plane every 45 degree angle to the horizontal, thus allowing measurements at other ultrasonic paths, procedure that showed to minimize the uncertainty associated with the flow measurement. The metrological characterization of this measurement procedure, qualifies the meter to be used as a in situ traveling calibration standard of flow meters, which prevents its removal for calibration in laboratory. The alternative methodology calibration proposed was validated experimentally in loop especially built at PUC-Rio to reproduce the field measurement conditions.
20
Temeepattanapongsa, Sathaporn. "Unified Equations for Cutthroat Flumes Derived from a Three-Dimensional Hydraulic Model." DigitalCommons@USU, 2012. https://digitalcommons.usu.edu/etd/1308.
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Computational fluid dynamics software was used to simulate the hydraulic behavior of 51 Cutthroat flume (CTF) sizes under various flow conditions, including 24 standard sizes with throat widths (W) from 0.051 to 1.219 m (2 inches to 4 ft), flume scale lengths (L) ranging from 0.457 to 2.743 m (1.5 - 9 ft), constriction ratios (W/L) of 1/9, 2/9, 3/9, and 4/9, and 27 non-standard flumes of intermediate sizes. The validity and accuracy of the simulation results were demonstrated using laboratory data from other studies for 16 of the standard flume sizes and three non-standard sizes. By using the depth-discharge data for 24 standard CTFs obtained from the modeling, a series of "best-fit" calibrations of existing separate free- and submerged-flow rating equations were performed for each of the 24 standard-sized CTFs. A new unified rating equation for free- and submerged-flow conditions for the standard CTF sizes was proposed by comparing a set of empirical equations. The performance of the unified rating equation was also analyzed in order to determine the technical desirability of the equations as substitutes for the existing separate free- and submerged-flow rating equations. For the free-flow rating, the discharge parameters in the traditional equation are generalized to be applicable to any of the CTF sizes with flume lengths ranging from 0.457 to 2.743 m (1.5 - 9 ft), and the constriction ratio ranging from 1/9 to 4/9. This allows the application of CTFs with greater accuracy than the previously available equation. With the new generic-fit equations for the free-flow rating parameters, the discharge error is 4% from the standard discharge, with an average error of 2.2% for full-scale discharge. The generic unified rating equations proposed herein are also applicable to any of the CTF sizes, varying among the 24 standard sizes with flume lengths ranging from 0.457 to 2.743 m (1.5 - 9 ft) and the constriction ratio ranging from 1/9 to 4/9. With the generic-fit equations for the calibration parameters as derived herein, the discharge error is 6 - 8% compared to the standard discharge, and 2 - 3% for full-scale discharge.
21
Hoffie, Andreas Frank. "Convection Calibration of Schmidt-Boelter Heat Flux Gages in Shear and Stagnation Air Flow." Thesis, Virginia Tech, 2006. http://hdl.handle.net/10919/31422.
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This work reports the convection calibration of Schmidt-Boelter heat flux gages in shear and stagnation air flow. The gages were provided by Sandia National Laboratories and included two one-inch diameter and two one-and-one-half-inch diameter Schmidt-Boelter heat flux gages. In order to calibrate the sensors a convection calibration facility has been designed, including a shear test stand, a stagnation test stand, an air heater and a data acquisition system. The current physical model for a combined radiation and convection heat transfer environment uses an additional thermal resistance around the heat flux gage. This model clearly predicts a non-linear dependency of the gage sensitivity over a range of heat transfer coefficients. A major scope of this work was to experimentally verify the relation found by the model assumptions. Since the actual heat sink temperature is not known and cannot be measured, three different cases have been examined resulting in three different sensitivities for one pressure value, which is the gage sensitivity for the not cooled case and the gage sensitivity for the cooled case, based on the plate temperature or on the cooling water temperature. All of the measured sensitivities for shear as well as for stagnation flow fit well in the theory and show the non-linear decay for increasing heat transfer coefficient values. However, the obtained data shows an offset in the intersection with the sensitivity at zero heat transfer coefficient. This offset might arise from different radiation calibration techniques and different surface coatings of test gage and reference standard.Master of Science
22
Wong, Wai-tak, and 王偉德. "Calibration of new sheared delay formulae for the estimation of queuesand delays in TRANSYT." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31223680.
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João, Martins. "Inverse Calibration of a Groundwater Flow Model for the Almádena-Odeáxere Aquifer System (Algarve – Portugal)." Thesis, Universidade do Algarve, 2007. http://hdl.handle.net/10919/71617.
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The present work consisted on the characterization of the spatial distribution of hydraulic parameters on the Almádena-Odeáxere aquifer system (AO) using the automatic calibration of a finite-element numeric model, in order to improve the simulation accuracy of the aquifer’s hydraulic behaviour. This development has its foundations based on model variants already implemented at the University of Algarve to investigate the hydraulic properties of the AO on the framework of the regional scale groundwater flow studies concerning Algarve aquifers. The state-of-the-art of the aquifer’s hydrogeology was based on previous investigations, taking place on the last years in Algarve, but also on recent fieldwork, namely on the collection of field data from a monitoring network, designed in articulation with the “POCTI/AMB/57432/2004” investigation project, which provided the feedback information needed for the improvement of model variants developed during the course of the present work. Instead of using a classic, time consuming, trial and error approach for the purpose of determining hydraulic parameters controlling groundwater flow at AO, an automatic inverse calibration algorithm was used, allowing the achievement of parameter distribution values capable of generating realistic hydraulic flow simulations. The Gauss-Marquardt-Levenberg method of nonlinear parameter estimation, available at the PEST algorithm was assembled to the finite element flow model, which is based in the use of the Galerkin method of weighted residuals. The results obtained by the use of the inverse method have revealed a good fit between simulated and measured head values, since the correlation coefficient, R, value was higher than 0,9 (0,9967) and the sum-of-squared weighted residuals between model outcomes and corresponding field data (i.e. the objective function, F) was only 4,56 m. The obtained spatial distribution of transmissivity, ranging from 86 m2/day to 8158 m2/day on 16 zones, allowed a step further on the reliability of future simulations of spatial distribution and temporal evolution of state variables in natural conditions and considering different scenarios of water use.
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Robinson, Matthew J. "Simultaneous lift, moment and thrust measurement on a scramjet in hypervelocity flow /." [St. Lucia, Qld.], 2003. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17611.pdf.
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Smith, Brandon Joseph. "Development and Initial Testing of a Micro-Newton Torsion Pendulum with Gas-Dynamic Calibration." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/88081.
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A novel torsion pendulum thrust test stand for micro-Newton-scale spacecraft thrusters is described. The stand is designed to be robust against electromagnetic interference effects internal or external to the thruster being tested. The design and testing of a
gas-dynamic calibration thruster is included. This thruster is fully self-contained on the pendulum arm, with no external wires or feedlines connected to the device and impacting the dynamic response of the underlying pendulum. Initial calibration results are shown. Zero drift and hysteresis are present in the results, evidenced by a constant steady-state displacement drift and a return to a different displacement after shutdown of the calibration thruster. Results are compared to theoretical solutions of the equation of motion. An external forcing function of facility effects is described for discrepancies between results and the theoretical solution. Further work to eliminate these effects and add damping are proposed.MS
Many recently proposed space missions require very fine vehicle attitude and position control in support of their science objectives. Thrusters with the ability to provide this control are currently in development, from laboratory proofs of concept to initial test flights on pathfinding missions. The low levels of thrust produced by these devices, in the range of less than the weight of a mosquito, require specialized test stands with very fine resolution. This thesis describes a novel torsion pendulum design for measuring these thrusters as well as initial validation results from its calibration system using rarefied gas flow. This calibration device is fully-contained on the device’s arm, removing many common sources of compensation factors which are often needed for other test stand designs. A custom-built displacement measuring system for determining angular motion of the pendulum arm is described which allows for measuring angular displacements of the arm to the level of arcseconds and potentially fractions thereof. Initial results suggest measurement of the expected levels of thrust, while some work remains to remove lingering sources of error and achieve more precise thrust data.
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Lukkari, Ingrid. "Flow injection systems for process analytical chemistry." Doctoral thesis, Umeå universitet, Kemiska institutionen, 1995. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-114755.
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Flow injection systems have great potential for sample handling and analysis in process analytical chemistry. The flexibility and versatility of flow injection manifolds can he utilized in specific applications of sample conditioning and analysis. An overview of various flow injection methods, including flow reversals, double injection, and sequential injection is given, as well as different clean-up methods, such as gas diffusion, solid phase extraction, dialysis, and solvent extraction. Calibration techniques, such as single standard and multivariate calibration are also discussed. In addition, different aspects of process analytical chemistry, in particular sampling and sample handling, are discussed. The papers in this thesis describe a number of flow systems, where gradient-, gas diffusion-, and solid phase extraction- methodologies are applied, all of which have potential use in process analytical chemistry. Paper I is focused on multicomponent analysis of mixtures of organic acids by mathematically extracting information from complex spectra. The selectivity is improved by generating pH-gradients in the flow system. In paper II, the methodology of sensor injection is described and electrochemical and spectroscopic sensors are implemented in a sequential injection system. The method is illustrated by using pH sensors and a glucose electrode. Ammonia and ammonium ions are determined on-line to a bioprocess by gas diffusion in paper III. The benefit of frequent re-calibrations and in-line cleaning sequences are demonstrated. Finally a method for on-line determination of o-diphenols in the kraft process has been developed (paper IV). The o-diphenols are isolated from black liquor samples by solid phase extraction and thereafter transferred to a high performance liquid chromatography system for separation and quantification.Diss. (sammanfattning) Umeå : Umeå universitet, 1996, Härtill 4 uppsatser
digitalisering@umu
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Parkin, John D. "Microcantilevers : calibration of their spring constants and use as ultrasensitive probes of adsorbed mass." Thesis, University of St Andrews, 2013. http://hdl.handle.net/10023/3608.
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The dynamic properties of several rectangular and V-shaped microcantilevers were investigated. Particular attention was paid to the higher flexural eigenmodes of oscillation. The potential of the higher flexural modes was demonstrated through the use of cantilevers as standalone sensors for adsorbed mass. The mass adsorbed on the surface of a cantilever was in the form of a homogeneous water layer measured as a function of relative humidity. The minimum detectable water layer thicknesses were 13.7 Å, 3.2 Å, 1.1 Å, and 0.7 Å for the first four modes of a rectangular cantilever, clearly demonstrating enhanced accuracy for the higher eigenmodes of oscillation. These thicknesses correspond to minimum detectable masses of 33.5 pg, 7.8 pg, 2.7 pg and 1.7 pg for the first four modes. For quantitative applications the spring constants of each cantilever must be determined. Many methods exist but only a small number can calibrate the higher flexural eigenmodes. A method was developed to simultaneously calibrate all flexural modes of microcantilever sensors. The method was demonstrated for the first four eigenmodes of several rectangular and V-shaped cantilevers with nominal fundamental spring constants in the range of 0.03 to 1.75 N/m. The spring constants were determined with accuracies of 5-10 %. Spring constants of the fundamental mode were generally in agreement with those determined using the Sader method. The method is compatible with existing AFM systems. It relies on a flow of gas from a microchannel and as such poses no risk of damage to the cantilever beam, its tip, or any coating. A related method was developed for the torsional modes of oscillation. Preliminary results are shown for the fundamental mode of a rectangular cantilever. The method can be easily extended to the higher torsional modes, V-shaped cantilevers, and potentially, the flapping modes of the legs of V-shaped microcantilevers.
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Khan, Muhammad Alam Z. "Transient engine model for calibration using two-stage regression approach." Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/8456.
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Engine mapping is the process of empirically modelling engine behaviour as a function of adjustable engine parameters, predicting the output of the engine. The aim is to calibrate the electronic engine controller to meet decreasing emission requirements and increasing fuel economy demands. Modern engines have an increasing number of control parameters that are having a dramatic impact on time and e ort required to obtain optimal engine calibrations. These are further complicated due to transient engine operating mode. A new model-based transient calibration method has been built on the application of hierarchical statistical modelling methods, and analysis of repeated experiments for the application of engine mapping. The methodology is based on two-stage regression approach, which organise the engine data for the mapping process in sweeps. The introduction of time-dependent covariates in the hierarchy of the modelling led to the development of a new approach for the problem of transient engine calibration. This new approach for transient engine modelling is analysed using a small designed data set for a throttle body inferred air ow phenomenon. The data collection for the model was performed on a transient engine test bed as a part of this work, with sophisticated software and hardware installed on it. Models and their associated experimental design protocols have been identi ed that permits the models capable of accurately predicting the desired response features over the whole region of operability. Further, during the course of the work, the utility of multi-layer perceptron (MLP) neural network based model for the multi-covariate case has been demonstrated. The MLP neural network performs slightly better than the radial basis function (RBF) model. The basis of this comparison is made on assessing relevant model selection criteria, as well as internal and external validation ts. Finally, the general ability of the model was demonstrated through the implementation of this methodology for use in the calibration process, for populating the electronic engine control module lookup tables.
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Cubas, Gonzales Tania Lizeth, Alcedo Rousbel Ricardo Rondon, and Torres Fernando Mauricio Tarquino. "Best HCM deterministic model calibrated for capacity analysis of basic segments of freeways in Lima." Institute of Electrical and Electronics Engineers Inc, 2020. http://hdl.handle.net/10757/656413.
Full textAbstract:
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado.In traffic engineering, the assessment of capacity in basic segment of freeway is a critical factor for planning, design and operational analysis of the freeway facilities. Thereby, the Highway Capacity Manual - HCM is the main guide used in many countries of the world including Perú that contain the methodology to estimate freeway capacity in traffic studies. Nevertheless, the information of vehicular traffic used for the construction of the models proposed by the HCM, reflect the characteristics of North American features. Therefore, its application in other traffic conditions, must be backed by studies of the local conditions and calibrations of the models proposed, hereby, adjusting to each city. The objetive of this research, is calibrate and compare of the HCM 2010 and HCM 2016 models, starting off the traffic engineering study in Panamericana Sur freeway located in Lima, Perú. The report will recommended the application of a calibrated model that best represents the local Peruvian conditions. The results of this study suggest that the model of calibrated capacity HCM2016, is the best representation, with a reliability of 97%, the local behavior of the basic freeway segments in function of the speed and the flow intensity. After applying the calibrated model into basic freeway segments concessioned by Rutas de Lima SAC, it was reflected that the use of the HCM2000, employed by this Company, show flow intensities within a level of service - LOS D, while, the calibrated HCM2016 shows us that those values are found, in reality, within a level of service - LOS E.
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Pezouvanis, Antonios. "Engine modelling for virtual mapping : development of a physics based cycle-by-cycle virtual engine that can be used for cyclic engine mapping applications, engine flow modelling, ECU calibration, real-time engine control or vehicle simulation studies." Thesis, University of Bradford, 2009. http://hdl.handle.net/10454/4419.
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After undergoing a study about current engine modelling and mapping approaches as well as the engine modelling requirements for different applications, a major problem found to be present is the extensive and time consuming mapping procedure that every engine has to go through so that all control parameters can be derived from experimental data. To improve this, a cycle-by-cycle modelling approach has been chosen to mathematically represent reciprocating engines starting by a complete dynamics crankshaft mechanism model which forms the base of the complete engine model. This system is modelled taking into account the possibility of a piston pin offset on the mechanism. The derived Valvetrain model is capable of representing a variable valve lift and phasing Valvetrain which can be used while modelling most modern engines. A butterfly type throttle area model is derived as well as its rate of change which is believed to be a key variable for transient engine control. In addition, an approximation throttle model is formulated aiming at real-time applications. Furthermore, the engine inertia is presented as a mathematical model able to be used for any engine. A spark ignition engine simulation (SIES) framework was developed in MATLAB SIMULINK to form the base of a complete high fidelity cycle-by-cycle simulation model with its major target to provide an environment for virtual engine mapping procedures. Some experimental measurements from an actual engine are still required to parameterise the model, which is the reason an engine mapping (EngMap) framework has been developed in LabVIEW, It is shown that all the moving engine components can be represented by a single cyclic variable which can be used for flow model development.
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Jeřábek, Martin. "Sběr dat pomocí LabVIEW." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219326.
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The main objective of this work is to create a program for automatic operation of measuring test track. The track is used for multi-hole velocity probes calibration. Normalized orifice plate is used as measurement standard. The program requires the user to enter certain information, which are not measured directly e.g. the values of measuring resistors, static air pressure. After entering this information, measurement can be started. The measurements are carried out simultaneously on the both flowmeters and on the thermomether Pt 100. The actual density of flowing medium is calculated from the measured temperature. Because the measurement is parallel, the calibrated flowmeter can be calibrated during the measurement.
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Nichols, Michael. "Quantitative basis for component factors of gas flow proportional counting efficiencies." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31834.
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Thesis (Ph.D)--Mechanical Engineering, Georgia Institute of Technology, 2010.Committee Co-Chair: Hertel, Nolan; Committee Co-Chair: Kahn, Bernd; Committee Member: Kulp, David; Committee Member: Lee, Eva; Committee Member: Wang, Chris. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Maštera, Martin. "Měřicí a linearizační zobrazovací jednotka pro průtokoměry." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-221061.
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Linearization display unit will receive pulses from a gear flow meter KRACHT whose frequency corresponds to a flow. The measured value is flow that nonlinearly depends on the temperature and viscosity of the medium. The dependency is described by calibration curves for each flow meter. The task of the diploma thesis is to design, implement, and verify the operation of the display unit, which calculates the actual flow rate from the input data (pulse rate, temperature, viscosity, and flow meter calibration curves). The device will contain a suitable user interface to display all measured values, inputs for connecting measuring sensors, and outputs for transmission of measured data. A part of the device will be a USB interface for configuration and uploading calibration curves from a PC application, which is designed by diploma student.
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Hansson, Klas. "Water and Heat Transport in Road Structures : Development of Mechanistic Models." Doctoral thesis, Uppsala University, Department of Earth Sciences, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4822.
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The coupled transport of water and heat, involving freezing and thawing, in the road structure and its immediate environment is important to consider for optimal design and maintenance of roads and when assessing solute transport, of e.g. de-icing salt, from roads. The objective of this study was to develop mechanistic models, and measurement techniques, suitable to describe and understand water flow and heat flux in road structures exposed to a cold climate.
Freezing and thawing was accounted for by implementing new routines in two numerical models (HYDRUS1D/2D). The sensitivity of the model output to changes in parameter values and operational hydrological data was investigated by uncertainty and sensitivity analyses. The effect of rainfall event characteristics and asphalt fractures on the subsurface flow pattern was investigated by scenario modelling. The performance of water content reflectometers (WCR), measuring water content, was evaluated using measurements in two road structure materials. A numerical model was used to simulate WCR sensor response. The freezing/thawing routines were stable and provided results in agreement with laboratory measurements. Frost depth, thawing period, and freezing-induced water redistribution in a model road was greatly affected by groundwater level and type of subgrade. The simulated subsurface flow patterns corresponded well with published field observations. A new method was successful in enabling the application of time domain reflectometer (TDR) calibration equations to WCR output. The observed distortion in sampling volume for one of the road materials could be explained by the WCR sensor numerical model. Soil physical, hydrological, and hydraulic modules proved successful in simulating the coupled transport of water and heat in and on the road structure. It was demonstrated in this thesis that numerical models can improve the interpretation and explanation of measurements. The HYDRUS model was an accurate and pedagogical tool, clearly useful in road design and management.
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Sedlák, Daniel. "Posouzení časových změn kalibračních charakteristik vodoměrných vrtulí." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-392212.
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Diploma’s thesis is focused on analysis of the time changes of calibration characteristics independent type of current-meters, processing by the calibration data and their evaluation and subsequent comparison with related research. This thesis describes the proces of calibration of current-meters.
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Pedersen, Jonas. "Site Application of a Channel Network Model for Groundwater Flow and Transport in Crystalline Rock." Thesis, Uppsala universitet, Luft-, vatten och landskapslära, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-354486.
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Groundwater flow and transport in deep crystalline rock is an important area of research. This is partly due to its relevance for constructing a long term repository for storing radioactive spent nuclear fuel in deep bedrock. Understanding the behavior of flow and transport processes in deep crystalline rock is crucial in developing a sustainable solution to this problem. This study aims to increase the understanding of how channel network models (CNM) can be applied to represent groundwater flow and solute transport in sparsely fractured crystalline rock under site specific conditions. A main objective was to determine how to incorporate structural and hydrogeological site characterization data in the construction of the CNMs. In addition to this, the associated key parameters of the CNMs were investigated to gain further understanding of model site application. To that end, a scripting approach with the python scripting library Pychan3d was used to create alternative channel network representations of a field site. A conceptual discrete fracture network (DFN) model was constructed using field site data obtained from a structural model of the fractures present at the site of the Tracer Retention Understanding Experiments (TRUE) - Block Scale at the Äspö Hard Rock Laboratory (HRL). This conceptual model was used as a base for constructing two different alternatives, denoted respectively as sparse and dense, of a CNM. The sparse CNM consisted of a limited amount of channels for each fracture, while the dense CNM acted as a DFN proxy, taking the full extent of the fracture areas into account and creating a dense, large network of flow channels for each fracture. In order to verify the performance of the generated CNMs, a reproduction of tracer tests performed at the same specific field site was attempted using a particle tracking technique. In addition to this, long term predictions of solute transport without the interference of the pumps used during the tracer tests were done in order to estimate transport time distributions. Pychan3d and the scripting approach was successfully used to create CNMs respecting specific conditions from the TRUE-Block Scale site. The sparse CNM was found to give very adequate flow and transport responses in most cases and to be relatively easier to calibrate than its dense counterpart. The long term transport predictions at the site according to the models seem to follow a channelized pattern, with only a few select paths for transport. The difficulties encountered in matching the dense CNM with the tracer tests most likely stem from difficulties in flow calibration, as well as certain key parameters being assigned too generically.
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Blythe, Kevin S. "A methodology of aggregating discrete microscopic traffic data for macroscopic model calibration and nonequilibrium visual detection purposes." Ohio : Ohio University, 1991. http://www.ohiolink.edu/etd/view.cgi?ohiou1183653868.
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Darroudi, Ali. "Variable Speed Limit Strategies to Reduce the Impacts of Traffic Flow Breakdown at Recurrent Freeway Bottlenecks." FIU Digital Commons, 2014. http://digitalcommons.fiu.edu/etd/1705.
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Variable Speed Limit (VSL) strategies identify and disseminate dynamic speed limits that are determined to be appropriate based on prevailing traffic conditions, road surface conditions, and weather conditions. This dissertation develops and evaluates a shockwave-based VSL system that uses a heuristic switching logic-based controller with specified thresholds of prevailing traffic flow conditions. The system aims to improve operations and mobility at critical bottlenecks. Before traffic breakdown occurrence, the proposed VSL’s goal is to prevent or postpone breakdown by decreasing the inflow and achieving uniform distribution in speed and flow. After breakdown occurrence, the VSL system aims to dampen traffic congestion by reducing the inflow traffic to the congested area and increasing the bottleneck capacity by deactivating the VSL at the head of the congested area. The shockwave-based VSL system pushes the VSL location upstream as the congested area propagates upstream. In addition to testing the system using infrastructure detector-based data, this dissertation investigates the use of Connected Vehicle trajectory data as input to the shockwave-based VSL system performance. Since the field Connected Vehicle data are not available, as part of this research, Vehicle-to-Infrastructure communication is modeled in the microscopic simulation to obtain individual vehicle trajectories. In this system, wavelet transform is used to analyze aggregated individual vehicles’ speed data to determine the locations of congestion.
The currently recommended calibration procedures of simulation models are generally based on the capacity, volume and system-performance values and do not specifically examine traffic breakdown characteristics. However, since the proposed VSL strategies are countermeasures to the impacts of breakdown conditions, considering breakdown characteristics in the calibration procedure is important to have a reliable assessment. Several enhancements were proposed in this study to account for the breakdown characteristics at bottleneck locations in the calibration process.
In this dissertation, performance of shockwave-based VSL is compared to VSL systems with different fixed VSL message sign locations utilizing the calibrated microscopic model. The results show that shockwave-based VSL outperforms fixed-location VSL systems, and it can considerably decrease the maximum back of queue and duration of breakdown while increasing the average speed during breakdown.
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Vieira, Junior Francisco Ubaldo. "Analise do perfil hidrodinamico em diferentes modelos de bombas de roletes utilizadas em circulação extracorporea." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/309535.
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Orientador: Reinaldo Wilson VieiraTese (doutorado)- Universidade Estadual de Campinas, Faculdade de Ciencias Medicas
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Resumo: Introdução: Dentre os equipamentos utilizados em circulação extracorpórea, as bombas de roletes têm grande importância, com modelos disponíveis de vários fabricantes. O ajuste dos roletes é um fator importante nas taxas de hemólise e o potencial hemolítico difere em cada um deles. Pesquisadores nem sempre abordam detalhes sobre os perfis do leito rígido supondo que as formas padronizadas de ajuste garantem valores iguais e comparáveis para todos os modelos de bombas de roletes. Dispomos principalmente de dois métodos para o ajuste de bombas de roletes e nenhum deles considera as características de impulsão do fluido, definida pelo perfil do leito rígido. Objetivo: O objetivo desse trabalho é analisar o perfil hidrodinâmico de três diferentes modelos de bombas de roletes comercializados no Brasil e sua influência no fluxo e refluxo. Materiais e Métodos: Foram utilizados tubos de silicone de 9,5x1,6; 9,5x2,4; 13x2,4 mm de diâmetro de dois fornecedores diferentes. Os testes foram realizados em solução fisiológica e solução análoga ao sangue. O perfil hidrodinâmico de três bombas de roletes foi realizado por medidas de velocidade de queda e calibração dinâmica. Foi investigada a variação das medidas de velocidade de queda com o tempo e testes de compressão em equipamento servo-hidráulico. Os refluxos foram visualizados em aspirador de sangue e reservatório de cardiotomia com medidas simultâneas. Resultados: Os perfis hidrodinâmicos apresentaram diferenças em suas variâncias para medidas de velocidade de queda (P<0,01) e calibração dinâmica (P<0,0001). A tensão residual nos tubos de silicone ocasionou redução nas medidas de velocidade de queda com o tempo (P<0,0002) e foram confirmadas pelos testes de compressão (P<0,0001). Conclusão: Os ajustes realizados pelos métodos de velocidade de queda e calibração dinâmica são dependentes da forma do leito rígido. Comparações envolvendo bombas de roletes devem ser feitas com cautela. A tensão residual em tubos de silicone compromete a repetitividade dos ajustes feitos pelo método de velocidade de queda.
Abstract: Introduction: Among the equipment used in cardiopulmonary bypass, roller pumps have great importance, with models available from several manufacturers. The roller adjustment is an important factor in the rates of hemolysis and the hemolytic potential differs in adjustment. Researchers do not always address details on the profiles of the raceway accepting that the forms of standardized settings ensure equal and comparable values for all models of roller pumps. There are two methods for setting roller pumps and none considers the dynamic characteristics of the fluid, defined by the profile of the raceway. Objective: The aim of this study is to analyze the hydrodynamic profile of three different models of roller pumps commercialized in Brazil and its influence on the flow and back flow. Materials and methods: We used silicone tubes of 9.5x1.6, 9.5 x2.4 and 13x2.4 mm in diameter from two different suppliers. The tests were performed in saline and solution analogous to blood. The hydrodynamic profile in three roller pumps was achieved by measurements of drop rate and dynamic calibration. The drop rate variations were investigated in silicone tubes by measurements of drop rate and the compression tests in servo-hydraulic equipment. Retrograde flows were viewed in blood aspirator and cardiotomy reservoir. Results: The hydrodynamic profiles showed differences in their variances for measurements of drop rate (P <0.01) and dynamic calibration (P <0.0001). The residual stress in the silicone tubes caused reduction in drop rate with time (P<0.0002) and were confirmed by compression tests (P <0.0001). Conclusion: The adjustments made by the methods of drop rate and dynamic calibration are dependent on the raceway profile. Comparisons involving roller pumps must be made with caution. The residual stress in the silicone tubes compromises repeatability of adjustments made by the drop rate method.
Doutorado
Pesquisa Experimental
Doutor em Cirurgia
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Phung, Viet-Anh. "Input Calibration, Code Validation and Surrogate Model Development for Analysis of Two-phase Circulation Instability and Core Relocation Phenomena." Doctoral thesis, KTH, Kärnkraftssäkerhet, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-202957.
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Code validation and uncertainty quantification are important tasks in nuclear reactor safety analysis. Code users have to deal with large number of uncertain parameters, complex multi-physics, multi-dimensional and multi-scale phenomena. In order to make results of analysis more robust, it is important to develop and employ procedures for guiding user choices in quantification of the uncertainties. The work aims to further develop approaches and procedures for system analysis code validation and application to practical problems of safety analysis. The work is divided into two parts. The first part presents validation of two reactor system thermal-hydraulic (STH) codes RELAP5 and TRACE for prediction of two-phase circulation flow instability. The goals of the first part are to: (a) develop and apply efficient methods for input calibration and STH code validation against unsteady flow experiments with two-phase circulation flow instability, and (b) examine the codes capability to predict instantaneous thermal hydraulic parameters and flow regimes during the transients. Two approaches have been developed: a non-automated procedure based on separate treatment of uncertain input parameters (UIPs) and an automated method using genetic algorithm. Multiple measured parameters and system response quantities (SRQs) are employed in both calibration of uncertain parameters in the code input deck and validation of RELAP5 and TRACE codes. The effect of improvement in RELAP5 flow regime identification on code prediction of thermal-hydraulic parameters has been studied. Result of the code validations demonstrates that RELAP5 and TRACE can reproduce qualitative behaviour of two-phase flow instability. However, both codes misidentified instantaneous flow regimes, and it was not possible to predict simultaneously experimental values of oscillation period and maximum inlet flow rate. The outcome suggests importance of simultaneous consideration of multiple SRQs and different test regimes for quantitative code validation. The second part of this work addresses core degradation and relocation to the lower head of a boiling water reactor (BWR). Properties of the debris in the lower head provide initial conditions for vessel failure, melt release and ex-vessel accident progression. The goals of the second part are to: (a) obtain a representative database of MELCOR solutions for characteristics of debris in the reactor lower plenum for different accident scenarios, and (b) develop a computationally efficient surrogate model (SM) that can be used in extensive uncertainty analysis for prediction of the debris bed characteristics. MELCOR code coupled with genetic algorithm, random and grid sampling methods was used to generate a database of the full model solutions and to investigate in-vessel corium debris relocation in a Nordic BWR. Artificial neural networks (ANNs) with classification (grouping) of scenarios have been used for development of the SM in order to address the issue of chaotic response of the full model especially in the transition region. The core relocation analysis shows that there are two main groups of scenarios: with relatively small (<20 tons) and large (>100 tons) amounts of total relocated debris in the reactor lower plenum. The domains are separated by transition regions, in which small variation of the input can result in large changes in the final mass of debris. SMs using multiple ANNs with/without weighting between different groups effectively filter out the noise and provide a better prediction of the output cumulative distribution function, but increase the mean squared error compared to a single ANN.Validering av datorkoder och kvantifiering av osäkerhetsfaktorer är viktiga delar vid säkerhetsanalys av kärnkraftsreaktorer. Datorkodanvändaren måste hantera ett stort antal osäkra parametrar vid beskrivningen av fysikaliska fenomen i flera dimensioner från mikro- till makroskala. För att göra analysresultaten mer robusta, är det viktigt att utveckla och tillämpa rutiner för att vägleda användaren vid kvantifiering av osäkerheter.Detta arbete syftar till att vidareutveckla metoder och förfaranden för validering av systemkoder och deras tillämpning på praktiska problem i säkerhetsanalysen. Arbetet delas in i två delar.Första delen presenterar validering av de termohydrauliska systemkoderna (STH) RELAP5 och TRACE vid analys av tvåfasinstabilitet i cirkulationsflödet.Målen för den första delen är att: (a) utveckla och tillämpa effektiva metoder för kalibrering av indatafiler och validering av STH mot flödesexperiment med tvåfas cirkulationsflödeinstabilitet och (b) granska datorkodernas förmåga att förutsäga momentana termohydrauliska parametrar och flödesregimer under transienta förlopp.Två metoder har utvecklats: en icke-automatisk procedur baserad på separat hantering av osäkra indataparametrar (UIPs) och en automatiserad metod som använder genetisk algoritm. Ett flertal uppmätta parametrar och systemresponser (SRQs) används i både kalibrering av osäkra parametrar i indatafilen och validering av RELAP5 och TRACE. Resultatet av modifikationer i hur RELAP5 identifierar olika flödesregimer, och särskilt hur detta påverkar datorkodens prediktioner av termohydrauliska parametrar, har studerats.Resultatet av valideringen visar att RELAP5 och TRACE kan återge det kvalitativa beteende av två-fas flödets instabilitet. Däremot kan ingen av koderna korrekt identifiera den momentana flödesregimen, det var därför ej möjligt att förutsäga experimentella värden på svängningsperiod och maximal inloppsflödeshastighet samtidigt. Resultatet belyser betydelsen av samtidig behandling av flera SRQs liksom olika experimentella flödesregimer för kvantitativ kodvalidering.Den andra delen av detta arbete behandlar härdnedbrytning och omfördelning till reaktortankens nedre plenumdel i en kokarvatten reaktor (BWR). Egenskaper hos härdrester i nedre plenum ger inledande förutsättningar för reaktortanksgenomsmältning, hur smältan rinner ut ur reaktortanken och händelseförloppet i reaktorinneslutningen.Målen i den andra delen är att: (a) erhålla en representativ databas över koden MELCOR:s analysresultat för egenskaperna hos härdrester i nedre plenum under olika händelseförlopp, och (b) utveckla en beräkningseffektiv surrogatsmodell som kan användas i omfattande osäkerhetsanalyser för att förutsäga partikelbäddsegenskaper.MELCOR, kopplad till en genetisk algoritm med slumpmässigt urval användes för att generera en databas av analysresultat med tillämpning på smältans omfördelning i reaktortanken i en Nordisk BWR.Analysen av hur härden omfördelas visar att det finns två huvudgrupper av scenarier: med relativt liten (<20 ton) och stor (> 100 ton) total mängd omfördelade härdrester i nedre plenum. Dessa domäner är åtskilda av övergångsregioner, där små variationer i indata kan resultera i stora ändringar i den slutliga partikelmassan. Flergrupps artificiella neurala nätverk med klassificering av händelseförloppet har använts för utvecklingen av en surrogatmodell för att hantera problemet med kaotiska resultat av den fullständiga modellen, särskilt i övergångsregionen.
QC 20170309
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Lavezzo, Luís Fernando de Queiroz. "Análise experimental e avaliação das incertezas em medição de líquidos com referência tipo ball prover." Universidade Federal do Espírito Santo, 2010. http://repositorio.ufes.br/handle/10/6246.
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Previous issue date: 2010-04-09This work is dedicated to the reference measurement of liquid flow aiming to deal with the peculiarities related to the subject, which reach great importance in commercial transactions involving typical interests of the oil industry. The flow measurement process however is not deterministic and involves a large number of variables that contributes to the doubt about of the real value that it proposes to measure. Such variables, which contribute to uncertainty in measurement, include a lot of aspects such constructive feature meter, fluid properties, environmental conditions and operator ability, for instance. This work presents a prototype project of a laboratorial scale ball prover, experimentally evaluate its performance, aiming to point out its alignment with the requirements established by the norms, considering the uncertainties in the measurement and the contribution of different lengths. Otherwise, it is procedured a comparison with a turbine meter calibrated by the manufacturer.
Este estudo se dedica à medição referencial de vazão de líquidos com o propósito de se lidar com as características específicas do funcionamento de um medidor, que tem suma importância nos interesses envolvendo transações comerciais na indústria de petróleo. O processo de medição de vazão envolve diversas variáveis que contribuem para a incerteza do real valor que se propõe medir. Estas variáveis vão desde características construtivas do medidor, propriedades do fluido a ser medido, das condições ambientais e perícia do operador. A proposta deste estudo é apresentar um projeto de protótipo laboratorial de medidor de referência tipo ball prover, avaliar experimentalmente seu desempenho e buscar se alinhar com os requisitos estabelecidos pelas normas. As incertezas inerentes à medição e sua contribuição em diferentes trechos será avaliada através de comparações com um medidor do tipo turbina, calibrado pelo fabricante.
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Březina, Jiří. "Časový vývoj metrologických charakteristik elektromagnetických indukčních měřidel bodových rychlostí." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-392151.
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This experimental diploma thesis investigates the changes in the metrological characteristics of the electromagnetic current meter of velocity. The theoretical part of the thesis includes a brief summary of technical and metrological characteristics of these types of devices. In addition, it describes the tested device, the test track, and the measurement procedure, which consists of two variants: long-term monitoring with a relatively regular monthly measurement interval and short-term monitoring with a regular daily measurement interval. The evaluation of the experimental work focuses on the repeatability and variability of the displayed point speed values and their stability over time. Furthermore, the parameters reported by the meter during long-term and short-term monitoring are compared to each other. The results are also compared with similar experiments.
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Her, Young Gu. "HYSTAR: Hydrology and Sediment Transport Simulation using Time-Area Method." Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/27503.
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A distributed approach can improve functionality of H/WQ (Hydrology and Water Quality) modeling by facilitating a way to explicitly incorporate spatial characteristics of a watershed into the model. The time-area approach, with its intuitive and inherently distributed concept, provides a simple method to simulate runoff mechanisms. This study developed a distributed model based on the time-area approach with the goal of improved utility and efficiency in H/WQ modeling.
Uncertainty is always introduced into watershed modeling because of imperfect knowledge and scale dependant spatial heterogeneity and temporal variability. Uncertainty analysis can provide a modeler, policy maker, and stakeholder with reliability information, better understanding, and better communication about the modeling results. This study quantified uncertainty of the model parameter and output through uncertainty analysis in order to assess risk in watershed management. The main goal of this study was to develop a hydrology and sediment transport model capable of routing overland flow using a time-area concept and providing reliability of the modeling results in a probabilistic manner through uncertainty analysis.
The HYSTAR (HYdrology and Sediment transport simulation using Time-ARea method) model incorporates a modified Curve Number (CN) method and the newly devised time-area routing method to estimate runoff. HYSTAR is capable of simulating direct runoff, base flow, soil moisture, and sediment load in a distributed manner and in an hourly time step. In the model, the modified CN and a continuity equation are used to calculate infiltration of the routed runoff as well as rainfall on every overland cell. The effective direct runoff volume is distributed over downstream areas using the newly developed routing method. A direct runoff hydrograph is constructed directly through the discrete convolution of the time-area histogram and the effective direct runoff volume
map without employing a unit hydrograph. In addition, sediment transport is simulated using the routing method and the sediment transport capacity approach without using a delivery ratio.
The sensitivity analysis found that the CN and root zone depth were the most critical parameters for runoff simulation with HYSTAR. The model provided acceptable performance in predicting runoff and sediment load of a subwatershed of the Owl Run Watershed (ORD) with the Nash-Sutcliffe efficiency coefficient and coefficient of determination greater than 0.5. However, it failed to reproduce runoff for a subwatershed of Polecat Creek Watershed (PCA), where data show that runoff is not immediately responsive to rainfall.
Uncertainty analysis revealed that the confidence intervals of the simulated monthly runoff and sediment load corresponded to 9.7 % and 10.2 % of their averages, respectively, at a significance level of 0.05. In addition, the average ranges of variation created by the Digital Elevation Model (DEM) and National Land Cover Data (NLCD) errors in the simulated monthly runoff and sediment load were equivalent to 7.5 % and 15.9 % of the average of their calibrated values, respectively. Based on the uncertainty analysis results, the Margin of Safety (MOS) of Total Maximum Daily Load (TMDL) were explicitly quantified as corresponding to 7.0 % and 21.3 % of the average of the simulated runoff and sediment load for ORD at significance level of 0.05.
In conclusion, the HYSTAR model provided a new way to explicitly simulate runoff and sediment load of a watershed in a distributed manner. The approach developed here retains the simplicity of a unit hydrograph approach without employing numerical methods. Uncertainty analysis found that parameter uncertainty had greater impact on the model output than did expected Geographic Information System (GIS) data errors. In addition, the impact of the topographic data error on the model output was greater than was that of the land cover data error. Finally, this study provided a proof that a 5 to 10 % MOS that many TMDL studies consider underestimates modeling uncertainty.Ph. D.
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Green, Steven. "Calorimetry at a future Linear Collider." Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/269648.
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This thesis describes the optimisation of the calorimeter design for collider experiments at the future Compact Linear Collider (CLIC) and the International Linear Collider (ILC). The detector design of these experiments is built around high-granularity Particle Flow Calorimetry that, in contrast to traditional calorimetry, uses the energy measurements for charged particles from the tracking detectors. This can only be realised if calorimetric energy deposits from charged particles can be separated from those of neutral particles. This is made possible with fine granularity calorimeters and sophisticated pattern recognition software, which is provided by the PandoraPFA algorithm. This thesis presents results on Particle Flow calorimetry performance for a number of detector configurations. To obtain these results a new calibration procedure was developed and applied to the detector simulation and reconstruction to ensure optimal performance was achieved for each detector configuration considered. This thesis also describes the development of a software compensation technique that vastly improves the intrinsic energy resolution of a Particle Flow Calorimetry detector. This technique is implemented within the PandoraPFA framework and demonstrates the gains that can be made by fully exploiting the information provided by the fine granularity calorimeters envisaged at a future linear collider. A study of the sensitivity of the CLIC experiment to anomalous gauge couplings that {affect} vector boson scattering processes is presented. These anomalous couplings provide insight into possible beyond standard model physics. This study, which utilises the excellent jet energy resolution from Particle Flow Calorimetry, was performed at centre-of-mass energies of 1.4 TeV and 3 TeV with integrated luminosities of 1.5$\text{ab}^{-1}$ and 2$\text{ab}^{-1}$ respectively. The precision achievable at CLIC is shown to be approximately one to two orders of magnitude better than that currently offered by the LHC. In addition, a study into various technology options for the CLIC vertex detector is described.
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Weller, Jessie. "Réduction de modèles par identification de systèmes et application au contrôle du sillage d'un cylindre." Thesis, Bordeaux 1, 2009. http://www.theses.fr/2009BOR13763/document.
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L’objectif est de construire un modèle d’écoulement qui se prête bien à des problèmes de contrôle, en associant un faible nombre de degrés de liberté à la possibilité de décrire la dynamique d’un écoulement relativement complexe. Dans ce travail nous considérons un écoulement bidimensionnel laminaire autour d’un cylindre carré. Des actionneurs placés sur le cylindre permettent un contrôle actif par sou?age et aspiration. Ce contrôle peut être dé?ni par rétroaction, exploitant des mesures de la vitesse dans le sillage du cylindre. Nous construisons un modèle d’ordre réduit (ROM) des équations de Navier-Stokes incompressibles, basé sur la technique de décomposition orthogonale aux valeurs propres (POD). Une façon classique de construire un tel modèle est de réaliser une projection Galerkin des équations sur le sous-espace réduit obtenu par POD. Un tel modèle peut cependant être peu précis, voire instable. Une technique de calibration est alors mise en place pour assurer la bonne représentativité dynamique du modèle. Nous dé?nissons ensuite une stratégie pour mettre à jour le modèle au cours d’un processus d’optimisation. La méthode est en?n appliquée pour réduire la di?érence entre l’écoulement contrôlé et la solution stationnaire instable à Re = 150The aim is to build a ?ow model adapted for control applications combining a low number of degrees of freedom with the possibility of describing relatively complex ?ows. In this work a two-dimensional laminar ?ow past a square cylinder is considered. Actuators placed on the cylinder enable active control by blowing and suction. Proportional feedback control can then be applied using velocity measurements taken in the cylinder wake. The proper orthogonal decom- position (POD) approach is used to build a low order model of the incompressible Navier-Stokes equations. A classical way of obtaining a Reduced-Order Model (ROM) is to perform a Galerkin projection of the equations onto the subspace spanned by the POD modes. Such a model can however be inaccurate, even unstable. A calibration technique is therefore applied, leading to a model that is accurate and robust to variations of the control parameters. A strategy is then de?ned to update the model within an optimisation loop. The method is tested at Re = 150 for reducing the di?erence between the actuated ?ow ?eld and the steady unstable solution
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Quintaes, Filipe de Oliveira. "Estudo da estimativa da incerteza de medi??o para determina??o do BS&W e da vaz?o aplicado no laborat?rio de avalia??o de medi??o do petr?leo." Universidade Federal do Rio Grande do Norte, 2006. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15495.
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Previous issue date: 2006-03-31The considered work presents the procedure for evaluation of the uncertainty related to the calibration of flow measurers and to BS&W. It is about a new method of measurement purposed by the conceptual project of the laboratory LAMP, at Universidade Federal do Rio Grande do Norte, that intends to determine the conventional true value of the BS&W from the total height of the liquid column in the auditor tank, hydrostatic pressure exerted by the liquid column, local gravity, specific mass of the water and the specific mass of the oil, and, to determine the flow, from total height of liquid column and transfer time. The calibration uses a automatized system of monitoration and data acquisition of some necessary largnesses to determine of flow and BS&W, allowing a better trustworthiness of through measurements
O trabalho proposto apresenta o procedimento para avalia??o da incerteza relacionada ? calibra??o de medidores de vaz?o e BS&W. Trata-se de um novo m?todo de medi??o proposto no projeto conceitual do Laborat?rio de Avalia??o de Medi??o em Petr?leo -LAMP, localizado na Universidade Federal do Rio Grande do Norte, que se prop?e a determinar o valor verdadeiro convencional do BS&W a partir da altura total da coluna l?quida no tanque auditor, press?o hidrost?tica exercida pela coluna l?quida, gravidade local, massa espec?fica da ?gua e a massa espec?fica do ?leo, e para a vaz?o em fun??o da altura total da coluna l?quida e do tempo de transfer?ncia. A calibra??o realizada conta com um sistema automatizado de monitora??o e aquisi??o de dados de algumas das grandezas necess?rias a determina??o da vaz?o e do BS&W, permitindo uma maior confiabilidade das medi??es realizadas
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Petrich, Jan. "Improved Guidance, Navigation, and Control for Autonomous Underwater Vehicles: Theory and Experiment." Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/27222.
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This dissertation addresses attitude control and inertial navigation of autonomous underwater vehicles (AUVs). We present theoretical justification for using simplified models, derive system identification algorithms, and verify our results through extensive field trials. Although this research focuses on small AUVs with limited instrumentation, the results are useful for underwater vehicles of any size.
For attitude control of aircraft systems, second-order equivalent pitch-axis models are common and extensively studied. However, similar analysis has not been performed for the pitch-axis motion of underwater vehicles. In this dissertation, we study the utility and the limitations of second-order approximate models for AUVs. We seek to improve the flight performance and shorten the time required to re-design a control algorithm when the shape, mass-distribution, and/or net buoyancy of an AUV/payload configuration changes.
In comparison to commonly implemented AUV attitude controllers, which neglect roll motion and address pitch and yaw dynamics separately, we derive a novel linear time-varying model that explicitly displays the coupling between pitch and yaw motion due to nonzero roll angle and/or roll rate. The model facilitates an Hâ control design approach that explicitly addresses robustness against those coupling terms and significantly reduces the effect of pitch and yaw coupling.
To improve AUV navigation, we investigate algorithms for calibrating a triaxial gyroscope using angular orientation measurements and formally define AUV trajectories that are persistently exciting and for which the calibration coefficients are uniformly observable. To improve AUV guidance, we propose a near real-time ocean current identification method that estimates a non-uniform flow-field using only sparse flow measurements.Ph. D.
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Martens, Aurélien. "Towards a measurement of the angle γ of the Unitarity Triangle with the LHCb detector at the LHC (CERN) : calibration of the calorimeters using an energy flow technique and first observation of the Bs0 -> D0K*0." Phd thesis, Université Paris Sud - Paris XI, 2011. http://tel.archives-ouvertes.fr/tel-00634057.
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A ce jour la détermination de l'angle γ du Triangle d'Unitarité de la matrice de Cabibbo-Kabayashi-Maskawa est statistiquement limitée par la rareté des transitions b→ u. La précision obtenue en combinant les résultats des expériences BABAR et BELLE est proche de 10°. L'expérience LHCb auprès du LHC présente un fort potentiel d'amélioration pour ce paramètre de violation de CP, notamment via la désintégration Bd0 -> D0K*0, un des canaux clés de cette mesure. Les désintégrations D0 -> Kπ, D0 -> Kππ0 et D0 -> Kπππ sont étudiées dans cette thèse. L'utilisation de désintégrations faisant intervenir des π0 nécessite un bon étalonnage en énergie des calorimètres électromagnétiques. Une méthode d'étalonnage intercellules du ECAL basée sur le flux d'énergie, permet d'obtenir une inter-calibration de l'ordre de 1,5 %, l'échelle d'énergie absolue étant obtenue par des méthodes indépendantes non étudiées ici. La détermination du rapport d'embranchement de la désintégration Bs0 -> D0K*0, première étape du programme aboutissant à la mesure de la violation de CP dans le canal Bd0 -> D0K*0, est réalisée relativement au rapport d'embranchement de Bd0 -> D0ρ0. Le résultat final obtenu avec 36 pb−1 de données collectées par LHCb en 2010 reste dominé par l'erreur statistique :BR(Bs0 -> D0K*0)/BR(Bd0 -> D0ρ0) = 1, 48 ± 0, 34 (stat) ± 0, 15 (syst) ± 0, 12 (fd/fs).
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Björnström, Albert. "Flödeskalibrering : Analys av kalibreringsprocesser." Thesis, Luleå tekniska universitet, Drift, underhåll och akustik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-70802.
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In December 2015 the Paris Agreement was signed in order to create a better global climate. According to the agreement, all countries 'emissions shall be reported to the UN. To be able to do this current emission levels must be known, which means measurement and calculation of emissions are necessary. The state-owned mining company Luossavaara Kiirunavaara AB (LKAB) operates iron ore mines in Northen Sweden. The iron ore products produced at the KK4 coal mill in Kiruna, consists of some additives that form carbon dioxide when burned. The amount of additives burned is measured using two flowmeters. To ensure that these meters have approved accuracy, annual calibrations are performed where measured volume is compared to a reference volume. In order to ensure that LKAB's calibration method works, another type of calibration was performed by an external company. The results between the two calibration methods differ significantly, which led to this report. The purpose of this work is to develop improvement proposals for LKAB's calibration method and to present suggestions on how LKAB can create better conditions for the other so called transit time calibration method. By analyzing each method and performing measurements, tests and calculations, weaknesses are noted. Tests show that a weakness of LKAB's calibration is that the level measurement method used is person-dependent. Level measurement with laser range gauge is tested with good results, why this type of measurement is recommended in the future. The main weakness with transit time method is primarily that it is sensitive to variation of the inner diameter of the pipe. In order for this method to provide reliable results, rebuilding of pipes and carefully measured internal diameter are required. Accurate flow measurement means that current carbon dioxide emissions can be calculated, which enables continued work towards set environmental goals. Flowmeters also have a significant role in product quality in KK4, which means that this report can contribute to higher quality and economic profitability.I december 2015 undertecknades Parisavtalet i syfte att skapa ett bättre globalt klimat. Enligt avtalet ska alla länders utsläpp redovisas till FN. En förutsättning för att Sverige ska kunna redovisa utsläppen är att nuvarande utsläppsnivåer är kända, varför mätning och beräkning av utsläpp är nödvändig. Det statligt ägda gruvbolaget Luossavaara Kiirunavaara AB (LKAB) driver järnmalmsgruvor i Malmfälten. Den järnmalmspellets som tillverkas vid kulsinterverket KK4 i Kiruna består till viss del av tillsatsmedel, som vid förbränning bildar koldioxid. Hur mycket tillsatsmedel som förbränns mäts med hjälp av två flödesmätare. För att säkerställa att dessa mätare har godkänd noggrannhet utförs årliga kalibreringar där uppmätt volym jämförs med en referensvolym. I syfte att säkerställa att LKAB:s kalibreringsmetod fungerar har ett externt företag utfört kalibrering med en annan metod där mätsensorer placeras på tillsatsmedelledningen. Resultaten mellan de två kalibreringsmetoderna skiljer sig avsevärt, vilket föranlett denna rapport. Syftet med arbetet är att ta fram förbättringsåtgärder för LKAB:s kalibreringsmetod samt presentera förslag på hur LKAB kan skapa bättre förutsättningar för den andra så kallade pulshastighetsmetoden. Genom att analysera respektive kalibreringsmetod och utföra mätningar, tester och beräkningar tas svagheter fram. Tester visar att en svaghet med LKAB:s kalibrering är att den nivåmätningsmetod som används är personberoende. Nivåmätning med laseravståndsmätare testas med gott resultat varför denna typ av mätning rekommenderas framöver. En svaghet med pulshastigheten är att den är känslig för variation av rörens innerdiameter. För att denna metod ska ge tillförlitliga resultat krävs ombyggnation av ledningar samt noga uppmätt innerdiameter. Noggrann flödesmätning leder till att nuvarande koldioxidutsläpp kan beräknas vilket skapar förutsättningar för fortsatt arbete mot uppställda miljömål. Flödesmätarna har även en betydande roll för produktkvaliteten i KK4 vilket innebär att denna rapport kan bidra till högre kvalitet och ekonomisk lönsamhet.
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Tamayo, Cascan Edgar. "Towards using microscopic traffic simulations for safety evaluation." Thesis, KTH, Fordonsdynamik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-243486.
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Microscopic traffic simulation has become an important tool to investigate traffic efficiency and road safety. In order to produce meaningful results, incorporated driver behaviour models need to be carefully calibrated to represent real world conditions. In addition to macroscopic relationships such as the speed-density diagram, they should also adequately represent the average risk of accidents occurring on the road. In this thesis, I present a two stage computationally feasible multi-objective calibration process. The first stage performs a parameter sensitivity analysis to select only parameters with considerable effect on the respective objective functions to keep the computational complexity of the calibration at a manageable level. The second stage employs a multi-objective genetic algorithm that produces a front of Pareto optimal solutions with respect to the objective functions. Compared to traditional methods which focus on only one objective while sacrificing accuracy of the other, my method achieves a high degree of realism for both traffic flow and average risk.Mikroskopisk trafiksimulering har blivit ett viktigt verktyg för att undersöka trafik effektivitet och trafiksäkerhet. För att producera meningsfulla resultat måste inbyggda drivrutinsbeteendemodeller noggrant kalibreras för att representera verkliga förhållanden i världen. Förutom makroskopiska relationer, såsom hastighetsdensitetsdiagrammet, bör de också på ett adekvat sätt representera den genomsnittliga risken för olyckor som uppträder på vägen. I denna avhandling presenterar jag en tvåstegs beräkningsberättigbar mångsidig kalibreringsprocess. Det första steget utför en parameterkänslighetsanalysför att bara välja parametrar med stor effekt på respektive objektiv funktioner för att hålla kalibrerings komplexiteten på en hanterbar nivå. Det andra steget använder en mångriktig genetisk algoritm som ger framsidan av Pareto optimala lösningar med hänsyn till objektivfunktionerna. Jämfört med traditionella metoder som fokuserar på endast ett mål, samtidigt som man offrar den andra, ger min metod en hög grad av realism för både trafikflöde och genomsnittlig risk.