<p>The Large Hadron Collider (LHC) is the next large particle accelerator developed at CERN, constructed to enable studies of particles. The acceleration of the particles is carried out using magnets operating at about 1.9 K, a temperature achieved by regulating flow of superfluid helium. For economical reasons, control of the helium flow is based on feedback of virtual flow meter (VFT) estimates instead of real instrumentation.</p><p>The main purpose of this work is to develop a virtual flow meter with the possibility to estimate the flow by means of two different flow estimation methods; the Samson method that has previously been tested for the LHC, and the Sereg- Schlumberger method that has never before been implemented in this environment.</p><p>The virtual flow meters are implemented on PLCs using temperature and pressure measurements as input data, and a tool for generating the virtual flow meters and connect them to the appropriate physical instrumentation has also been developed.</p><p>The flow through a valve depends, among others, on some pressure and temperature dependent physical properties that are to be estimated with high accuracy. In this project, this is done by bilinear interpolation in twodimensional tables containing physical data, an approach that turned out to be more accurate than the previously used method with polynomial interpolation.</p><p>The flow measurement methods have been compared. Since they both derive from empirical studies rather than physical relations it is quite futile to find theoretical correspondencies, but the simulations of the mass flows can be compared. For low pressures, the results are fairly equal but they differ more for higher pressures. The methods have not been validated against true flow rates since there were no real measurements available before the end of this project.</p> / <p>Le Grand Collisionneur de Hadrons (Large Hadron Collider, LHC) est le prochain grand accélérateur de particules du CERN, construit pour permettre l’étude des particules. L’accélération des particules sera réalisée en utilisant des aimants supraconducteurs qui fonctionneront à 1.9 K et la température sera régulée en contrôlant le débit d’hélium superfluide. Pour des raisons économiques, la régulation du débit d’hélium sera basée sur les réponses des estimations des débitmètres</p><p>virtuels (Virtual flow meters, VFT) au lieu d’instrumentation réelle.</p><p>Le but principal de ce projet est de développer un débitmètre virtuel qui estimera le débit avec deux méthodes différentes ; la méthode Samson qui a déjà été mise en oeuvre pour le LHC, et la méthode Sereg-Schlumberger qui n’a pas encore été implémentée dans cet environnement.</p><p>Les débitmètres virtuels seront implémentés sur des PLCs avec des mesures de température et de pression comme données d’entrée. De plus, un outil pour générer les débitmètres et les relier avec l’instrumentation physique adéquat a été développé.</p><p>Le débit à travers d’une vanne dépend entre autres des propriétés physiques qui dépendent à leur tour de la température et de la pression. Ces propriétés devront être estimées avec une grande précision. Dans ce projet, cela est fait en appliquant une interpolation bilinéaire dans des tableaux de deux dimensions. Cette méthode s’est montrée plus précise qu’avec une méthode d’interpolation polynomiale.</p><p>Les deux méthodes de mesures de débit ont été comparées. Elles dérivent toutes les deux des études empiriques et non physiques, alors les similarités théoriques sont donc peu pertinentes, mais les résultats des simulations des débits peuvent être comparés. Pour des pressions basses, les méthodes sont quasiment équivalentes, mais les différences sont plus importantes pour les pressions plus hautes. Étant donné qu’il n’y avait pas de mesures disponibles avant la fin de ce projet, les méthodes n’ont pas été validées avec des débits réels.</p>

The response of slotted plate, Venturi meter and standard orifice to the presence of two phase, three phase and low differential flows was investigated. Two mixtures (air-water and air-oil) were used in the two-phase analysis while a mixture of air, water and oil was employed in the three-phase case. Due to the high gas void fraction (α>0.9), the mixture was considered wet gas. A slotted plate was utilized in the low differential pressure analysis and the discharge coefficient behavior was analyzed. Assuming homogeneous flow, an equation with two unknowns was obtained for the multi-phase flow analysis. An empirical relation and the differential response of the meters were used to estimate the variables involved in the equation. Good performance in the gas mass flow rate estimation was exhibited by the slotted and standard plates for the air-water flow, while poor results were obtained for the air-oil and air-water oil flows. The performance of all the flow meter tested in the analysis improved for differential pressures greater than 24.9 kPa (100 in_H2O). Due to the tendency to a zero value for the liquid flow, the error of the estimation reached values of more than 500% at high qualities and low differential pressures. Air-oil and air-water-oil flows show that liquid viscosity influences the response of the differential pressure meters. The best results for high liquid viscosity were obtained in the Venturi meter using the recovery pressure for the gas flow estimation at differential pressures greater than 24.9 kPa (100 in_H2O). A constant coefficient Cd was used for the low differential pressure analysis and results did show that for differential pressure less than 1.24 kPa (5 inH2O) density changes are less than 1% making possible the incompressible flow assumption. The average of the computed coefficients is the value of Cd.

Utility companies (electricity, gas, and water suppliers), governments, and researchers recognize an urgent need to deploy communication-based systems to automate data collection from smart meters and sensors, known as Smart Metering Infrastructure (SMI) or Automatic Meter Reading (AMR). A smart metering system is envisaged to bring tremendous benefits to customers, utilities, and governments. The advantages include reducing peak demand for energy, supporting the time-of-use concept for billing, enabling customers to make informed decisions, and performing effective load management, to name a few. A key element in an SMI is communications between meters and utility servers. However, the mass deployment of metering devices in the grid calls for studying the scalability of communication protocols. SMI is characterized by the deployment of a large number of small Internet Protocol (IP) devices sending small packets at a low rate to a central server. Although the individual devices generate data at a low rate, the collective traffic produced is significant and is disruptive to network communication functionality. This research work focuses on the scalability of the transport layer functionalities. The TCP congestion control mechanism, in particular, would be ineffective for the traffic of smart meters because a large volume of data comes from a large number of individual sources. This situation makes the TCP congestion control mechanism unable to lower the transmission rate even when congestion occurs. The consequences are a high loss rate for metered data and degraded throughput for competing traffic in the smart metering network. To enhance the performance of TCP in a smart metering infrastructure (SMI), we introduce a novel TCP-based scheme, called Split- and Aggregated-TCP (SA-TCP). This scheme is based on the idea of upgrading intermediate devices in SMI (known in the industry as regional collectors) to offer the service of aggregating the TCP connections. An SA-TCP aggregator collects data packets from the smart meters of its region over separate TCP connections; then it reliably forwards the data over another TCP connection to the utility server. The proposed split and aggregated scheme provides a better response to traffic conditions and, most importantly, makes the TCP congestion control and flow control mechanisms effective. Supported by extensive ns-2 simulations, we show the effectiveness of the SA-TCP approach to mitigating the problems in terms of the throughput and packet loss rate performance metrics. A full mathematical model of SA-TCP is provided. The model is highly accurate and flexible in predicting the behaviour of the two stages, separately and combined, of the SA-TCP scheme in terms of throughput, packet loss rate and end-to-end delay. Considering the two stages of the scheme, the modelling approach uses Markovian models to represent smart meters in the first stage and SA-TCP aggregators in the second. Then, the approach studies the interaction of smart meters and SA-TCP aggregators with the network by means of standard queuing models. The ns-2 simulations validate the math model results. A comprehensive performance analysis of the SA-TCP scheme is performed. It studies the impact of varying various parameters on the scheme, including the impact of network link capacity, buffering capacity of those RCs that act as SA-TCP aggregators, propagation delay between the meters and the utility server, and finally, the number of SA-TCP aggregators. The performance results show that adjusting those parameters makes it possible to further enhance congestion control in SMI. Therefore, this thesis also formulates an optimization model to achieve better TCP performance and ensures satisfactory performance results, such as a minimal loss rate and acceptable end-to-end delay. The optimization model also considers minimizing the SA-TCP scheme deployment cost by balancing the number of SA-TCP aggregators and the link bandwidth, while still satisfying performance requirements.

This paper details a method to compute absolute water velocity profiles from glider-based acoustic Doppler current profiler (ADCP) measurements based on the "shear method" developed for lowered ADCPs. The instrument is a 614-kHz Teledyne RDI ADCP integrated into the body of a Teledyne Webb Research Slocum Glider. Shear is calculated from velocity measurements and averaged over depth intervals to create a dive-averaged shear profile. Absolute velocities are computed by vertically integrating shear profiles yielding relative velocity profiles and then referencing them to dive-average velocity measurements calculated from glider dead-reckoning and GPS. Bottom-track referenced velocities also provide absolute velocities when bottom-tracking is available, and can be applied to relative velocities, producing absolute velocity profiles through linear fitting. Data quality control is based on ADCP percent good measurements. Compass heading bias corrections are applied to the raw ADCP measurements before averaging shear profiles. Comparison between simultaneous, full-water column velocities referenced to dive-average currents and those referenced to bottom-track profiles, resulted in RMS error values of 0.05 m s⁻¹ for both north and east components. During open ocean deployments, the glider ADCP recorded velocities concurrent and proximate to vessel ADCP measurements in waters of similar thermal characteristics. The combined comparison analysis resulted in RMS error values ranging 0.08-0.31 m s⁻¹ and 0.06-0.21 m s⁻¹ for north and east components, respectively. / Graduation date: 2013

Faced with a looming electricity crisis, the provincial government is calling for Ontarians to adopt a “culture of conservation”, and is planning to equip all residential dwellings with new metering infrastructure known as “smart meters” by 2010. In addition to providing residents with the ability to “shift” their electricity consumption from the most expensive “on-peak” times of the day, the data from these meters can be used to provide residents with detailed information, or feedback, regarding their consumption patterns. This research assessed whether electricity-use feedback affected households’ electricity consumption behaviour, whether feedback effected pro-conservation attitude changes, and what types of feedback were most effective in these regards. An initial mail survey was sent to 1,257 smart metered Milton, Ontario homes to obtain information regarding residents’ appliances and their consumption behaviour and attitudes. Of the 298 respondents, most of whom were living in homes that were less than seven years old, 106 were chosen to receive weekly household-specific feedback in various formats from July to October 2006. A follow-up survey was conducted to assess any changes in attitude as a result of the feedback, and weather-adjusted 2005 and 2006 consumption data were used to quantitatively discern any resulting consumption changes. While overall results revealed that the feedback made little difference in household consumption levels compared to the 2005 baseline period, there were some indications that it was effective in encouraging shifting, and had the opposite effect on overall conservation (i.e. it encouraged increased consumption). Also, while the comparison of “pre-” and “postfeedback” surveys revealed the feedback had no measured effect on encouraging proconservation attitudes, overall, customer acceptance of the feedback was high.

The Large Hadron Collider (LHC) is the next large particle accelerator developed at CERN, constructed to enable studies of particles. The acceleration of the particles is carried out using magnets operating at about 1.9 K, a temperature achieved by regulating flow of superfluid helium. For economical reasons, control of the helium flow is based on feedback of virtual flow meter (VFT) estimates instead of real instrumentation. The main purpose of this work is to develop a virtual flow meter with the possibility to estimate the flow by means of two different flow estimation methods; the Samson method that has previously been tested for the LHC, and the Sereg- Schlumberger method that has never before been implemented in this environment. The virtual flow meters are implemented on PLCs using temperature and pressure measurements as input data, and a tool for generating the virtual flow meters and connect them to the appropriate physical instrumentation has also been developed. The flow through a valve depends, among others, on some pressure and temperature dependent physical properties that are to be estimated with high accuracy. In this project, this is done by bilinear interpolation in twodimensional tables containing physical data, an approach that turned out to be more accurate than the previously used method with polynomial interpolation. The flow measurement methods have been compared. Since they both derive from empirical studies rather than physical relations it is quite futile to find theoretical correspondencies, but the simulations of the mass flows can be compared. For low pressures, the results are fairly equal but they differ more for higher pressures. The methods have not been validated against true flow rates since there were no real measurements available before the end of this project. / Le Grand Collisionneur de Hadrons (Large Hadron Collider, LHC) est le prochain grand accélérateur de particules du CERN, construit pour permettre l’étude des particules. L’accélération des particules sera réalisée en utilisant des aimants supraconducteurs qui fonctionneront à 1.9 K et la température sera régulée en contrôlant le débit d’hélium superfluide. Pour des raisons économiques, la régulation du débit d’hélium sera basée sur les réponses des estimations des débitmètres virtuels (Virtual flow meters, VFT) au lieu d’instrumentation réelle. Le but principal de ce projet est de développer un débitmètre virtuel qui estimera le débit avec deux méthodes différentes ; la méthode Samson qui a déjà été mise en oeuvre pour le LHC, et la méthode Sereg-Schlumberger qui n’a pas encore été implémentée dans cet environnement. Les débitmètres virtuels seront implémentés sur des PLCs avec des mesures de température et de pression comme données d’entrée. De plus, un outil pour générer les débitmètres et les relier avec l’instrumentation physique adéquat a été développé. Le débit à travers d’une vanne dépend entre autres des propriétés physiques qui dépendent à leur tour de la température et de la pression. Ces propriétés devront être estimées avec une grande précision. Dans ce projet, cela est fait en appliquant une interpolation bilinéaire dans des tableaux de deux dimensions. Cette méthode s’est montrée plus précise qu’avec une méthode d’interpolation polynomiale. Les deux méthodes de mesures de débit ont été comparées. Elles dérivent toutes les deux des études empiriques et non physiques, alors les similarités théoriques sont donc peu pertinentes, mais les résultats des simulations des débits peuvent être comparés. Pour des pressions basses, les méthodes sont quasiment équivalentes, mais les différences sont plus importantes pour les pressions plus hautes. Étant donné qu’il n’y avait pas de mesures disponibles avant la fin de ce projet, les méthodes n’ont pas été validées avec des débits réels.

Faced with a looming electricity crisis, the provincial government is calling for Ontarians to adopt a “culture of conservation”, and is planning to equip all residential dwellings with new metering infrastructure known as “smart meters” by 2010. In addition to providing residents with the ability to “shift” their electricity consumption from the most expensive “on-peak” times of the day, the data from these meters can be used to provide residents with detailed information, or feedback, regarding their consumption patterns. This research assessed whether electricity-use feedback affected households’ electricity consumption behaviour, whether feedback effected pro-conservation attitude changes, and what types of feedback were most effective in these regards. An initial mail survey was sent to 1,257 smart metered Milton, Ontario homes to obtain information regarding residents’ appliances and their consumption behaviour and attitudes. Of the 298 respondents, most of whom were living in homes that were less than seven years old, 106 were chosen to receive weekly household-specific feedback in various formats from July to October 2006. A follow-up survey was conducted to assess any changes in attitude as a result of the feedback, and weather-adjusted 2005 and 2006 consumption data were used to quantitatively discern any resulting consumption changes. While overall results revealed that the feedback made little difference in household consumption levels compared to the 2005 baseline period, there were some indications that it was effective in encouraging shifting, and had the opposite effect on overall conservation (i.e. it encouraged increased consumption). Also, while the comparison of “pre-” and “postfeedback” surveys revealed the feedback had no measured effect on encouraging proconservation attitudes, overall, customer acceptance of the feedback was high.

When consumers are able to buy electricity on an hourly instead of monthly basis, the demand side flexibility is likely to increase. One way to lower the cost of electricity is to move consumption from peak price hours to low price hours, a sort of inter-temporal substitution were the net energy use is unaffected. By simulating one example of inter-temporal substitution in the Swedish spot market during 2008-2010, we show that the general welfare effects are small in terms of a more efficient energy production, but that the transfer of resources from producers to consumers is large. Whether the welfare effect is positive or negative is highly dependent on future electricity prices, the introduction of renewable energy resources, and the price of the new technology needed for the demand side regulation. If 2010 is used as a reference case, the results from our specific case concludes that a natural investment equilibrium is reached when approximately 150 000 households invest in the proposed demand side regulation technology. Using the same reference year, we see that if 70 000 households participates the Net Present Welfare benefit is around 10% of the necessary investment cost; to be compared with the transfer of benefits from producers to consumers which estimates roughly 2100% of the necessary investment cost. We argue that this imbalance in potential welfare benefits between producers and consumers might slow down the process of increasing the general welfare.

Robust regression is a commonly required approach in industrial studies like data mining, quality control and improvement, and finance areas. Among the robust regression methods / Least Median Squares, Least Trimmed Squares, Mregression, MM-method, Least Absolute Deviations, Locally Weighted Scatter Plot Smoothing and Multivariate Adaptive Regression Splines are compared under contaminated normal distributions with each other and Ordinary Least Squares with respect to the multiple outlier detection performance measures. In this comparison / a simulation study is performed by changing some of the parameters such as outlier density, outlier locations in the x-axis, sample size and number of independent variables. In the comparison of the methods, multiple outlier detection is carried out with respect to the performance measures detection capability, false alarm rate and improved mean square error and ratio of improved mean square error. As a result of this simulation study, the three most competitive methods are compared on an industrial data set with respect to the coefficient of multiple determination and mean square error.

The response of slotted plate, Venturi meter and standard orifice to the presence of two phase, three phase and low differential flows was investigated. Two mixtures (air-water and air-oil) were used in the two-phase analysis while a mixture of air, water and oil was employed in the three-phase case. Due to the high gas void fraction (&#945;>0.9), the mixture was considered wet gas. A slotted plate was utilized in the low differential pressure analysis and the discharge coefficient behavior was analyzed. Assuming homogeneous flow, an equation with two unknowns was obtained for the multi-phase flow analysis. An empirical relation and the differential response of the meters were used to estimate the variables involved in the equation. Good performance in the gas mass flow rate estimation was exhibited by the slotted and standard plates for the air-water flow, while poor results were obtained for the air-oil and air-water oil flows. The performance of all the flow meter tested in the analysis improved for differential pressures greater than 24.9 kPa (100 in_H2O). Due to the tendency to a zero value for the liquid flow, the error of the estimation reached values of more than 500% at high qualities and low differential pressures. Air-oil and air-water-oil flows show that liquid viscosity influences the response of the differential pressure meters. The best results for high liquid viscosity were obtained in the Venturi meter using the recovery pressure for the gas flow estimation at differential pressures greater than 24.9 kPa (100 in_H2O). A constant coefficient Cd was used for the low differential pressure analysis and results did show that for differential pressure less than 1.24 kPa (5 inH2O) density changes are less than 1% making possible the incompressible flow assumption. The average of the computed coefficients is the value of Cd.