Increasing demand on freeway facilities is a major challenge facing urban areas in the United States and throughout the world. Active Traffic Management (ATM) strategies can be used to increase the performance of these facilities through improved operations without the significant expenditure associated with adding capacity. One ATM strategy that has been widely deployed in the current state of practice is ramp metering, which controls the traffic demand placed on a freeway. Merge control strategies are less prevalent and largely undeveloped. This study examines the recurrently congested northbound section of Interstate Highway 35 that approaches downtown Austin, Texas. Using the VISSIM microsimulation platform, a model of this segment was developed and calibrated to reflect current peak-hour congestion. Within this model, ramp metering and merge control technologies were implemented. The impacts on traffic throughput, speed and travel time for each of these proposed systems are evaluated. / text

Urban freeway demand that frequently exceeds capacity has caused many agencies to consider many options to reduce congestion. A series of solutions that falls under the Active Traffic Management (ATM) banner have shown promising potential. Perhaps the most popular ATM strategy is ramp metering. Ramp metering involves limiting the access of vehicles to freeways at an entrance ramp. By doing this, freeway throughput, speeds, and travel time reliability can be increased, while the number of traffic incidents can be decreased. This study examines the application of an innovative ramp metering strategy, Intersection Ramp Metering (IRM), at a section of Loop 1 in Austin, TX. IRM implements the ramp metering function at the intersection immediately upstream of the entrance ramp, rather than on the ramp itself. A microsimulation analysis of this application is performed in VISSIM, and the results confirm that freeway throughput (+10%), and system average travel time (-14%), can be improved, as well as several other performance measures. / text

Combination chemotherapies that introduce multi-agent treatments to target cancer cells are emerging as new paradigms to overcome chemotherapy resistance and side effects involved with conventional monotherapies. In environmental toxicology, characterizing effects of mixtures of toxins rather than simply analyzing the effect of single toxins are of significant interest. In order to determine such combination effects, it is necessary to systematically investigate interactions between different concentration-dependent components of a mixture. Conventional microtiter plate format based assays are efficient and cost-effective, however are not practical as the number of combinations increases drastically. Although robotic pipetting systems can overcome the labor-intensive and time-consuming limitations, they are too costly for general users. Microfluidic live cell screening platforms can allow precise control of cell culture microenvironments by applying accurate doses of biomolecular mixtures with specific mixing ratios generated through integrated on-chip microfluidic gradient generators. This thesis first presents a live cell array platform with integrated microfluidic network-based gradient generator which enables generation and dosing of 64 unique combinations of two cancer drugs at different concentrations to an 8 by 8 cell culture chamber array. We have developed the system into a fully automated microfluidic live cell screening platform with uniform cell seeding capability and pair-wise gradient profile generation. This platform was utilized to investigate the gene expression regulation of colorectal cancer cells in response to combination cancer drug treatment. The resulting cell responses indicate that the two cancer drugs show additive effect when sequential drug treatment scheme is applied, demonstrating the utility of the microfluidic live cell assay platform. However, large reagent consumption and difficulties of repeatedly generating the exact same concentrations and mixture profiles from batch to batch and device to device due to the fact that the generated gradient profiles or mixing ratios of chemicals have to rely on stable flow at optimized flow rate throughout the entire multi-day experiment limit the widespread use of this method. Moreover, producing three or more reagent mixtures require complicated microchannel structures and operating procedures when using traditional microfluidic network-based gradient generators. Therefore, an on-demand geometric metering-based mixture generator which facilitates robust, scalable, and accurate multi-reagent mixing in a high-throughput fashion has been developed and incorporated with a live cell array as a microfluidic screening platform for conducting combination drug or toxin assays. Integrated single cell trapping array allowed single cell resolution analysis of drugs and toxin effects. Reagent mixture generation and precise application of the mixtures to arrays of cell culture chambers repeatedly over time were successfully demonstrated, showing significantly improved repeatability and accuracy than those from conventional microfluidic network-based gradient generators. The influence of this improved repeatability and accuracy in generating concentration specified mixtures on obtaining more reliable and repeatable biological data sets were studied.

Orientador: Marina Sangoi de Oliveira Ilha / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-22T02:34:31Z (GMT). No. of bitstreams: 1 Monteiro_JorgeVenanciodeFreitas_D.pdf: 6374294 bytes, checksum: 2762eef420b569fb0b3cbd56d31652d6 (MD5) Previous issue date: 2013 / Resumo: A medição avançada de água e de gás combustível se constitui ainda em um desafio no Brasil, principalmente porque as empresas que a utilizam para a individualização de consumos surgiram quase que exclusivamente por iniciativa própria, na maioria dos casos por uma demanda das construtoras ou condomínios. Assim, trata-se de um mercado sem a devida regulamentação e normalização, com as decorrentes dificuldades de implementação. Este trabalho tem como objetivo caracterizar o contexto da medição avançada no país, identificando os principais fatores limitantes e facilitadores e, a partir disso, propor diretrizes para a sua implementação eficiente. Trata-se de uma pesquisa qualitativa em que, a partir da revisão da literatura e de uma pesquisa documental foram selecionadas inovações ligadas à medição avançada existentes em outros países, as quais serviram de base para a elaboração de entrevistas semipadronizadas realizadas com profissionais atuantes em concessionárias e em empresas operadoras de sistemas de medição. Entre as inovações avaliadas para um maior fomento da medição avançada, merecem destaque a criação do agente provedor e do agente de inspeção dos serviços de medição, pelas suas características de relativa facilidade de implantação em curto prazo no cenário delineado pelos coadjuvantes deste mercado, bem como de potencialidade de sanar problemas existentes / Abstract: The use of advanced metering in gas and water metering consumption is an ongoing challenge in Brazil, due to the fact that the players that deal with this activity have appeared in an unplanned manner, in most cases in response to demand from construction companies or condominiums. Its implementation is difficult since the market is not regulated or standardized. The purpose of this work is to describe the advance metering context in Brazil, to identify its limiting and facilitator factors, and, propose strategies for its introduction in an efficient manner. A qualitative research was carried out, and taking into consideration literature and documentation review, modern practices related to advanced metering from other countries were selected. To assess the feasibility of each strategy, semi-structured interviews were conducted at experts from utility companies and companies involved in the implementation of remote and individual metering systems. Among these strategies, the establishment of a metering service provider and the development of a metering systems inspection agent were highlighted due to the fact that they entail relatively simple actions that may be accomplished by local players involved directly in metering activities, as well as its potential to solve existing problems / Doutorado / Arquitetura e Construção / Doutor em Engenharia Civil

No description available.

The American Water Works Association (AWWA) and the International Water Association (IWA) have designated the volume of water not registered by water meters as a form of "apparent loss" in a distribution system. The term apparent is given because this volume is not technically a water loss, as is the case of wasted water from real leaks in the distribution system. Large volumes of apparent losses hurt the revenue of utilities that rely on water metering to bill their customers. This is critical to utilities given that billed consumption is often the main source of income to provide adequate service. This form of apparent losses is a challenge to water management, particularly, in the case of significant drought because of the uncertainty about the real volume of water consumed. Although the impact of apparent losses from a single residential service connection is not as significant compared to an industrial meter with low accuracy, the cumulative effect of apparent losses across residential users can be very significant. Until the early 2000's water utilities in the U.S. relied on mechanical water meters to measure residential water use. Since then, electronic meters with higher accuracy at low flow rates have been developed. Data collection from meters has also evolved as well, from the manual reading by an operator, to drive-by systems and most recently to remote readings using a network of transmitters/receivers (i.e., advanced metering infrastructure or AMI). An expectation of this dissertation is that it will help water utilities to have a better idea of the volume of apparent losses due to metering inaccuracy (i.e., registration error) and provide insights into the effects of installing AMI systems to residential metered water (MW). To achieve this goal, two main objectives are fulfilled 1) to expand on the knowledge of registration error (RE) in mechanical nutating-disc (ND) meters used to monitor residential consumption, and 2) to evaluate the impact of metering infrastructure upgrades on the volume of metered water (MW) from residential service connections. This dissertation follows the manuscript format with three journal articles constituting the main chapters after a general introduction characterizing the issues in Chapter 1. Chapter 2 is an experimental study that evaluates the influence of service time (ST) and volumetric throughput (TP) on the accuracy of ND meters within the recommended flow rates set by the U.S. water industry for meters with an internal diameter of ⅝-in. (15-mm). Over 300 meters removed from service were tested for accuracy. Key findings of this study are 1) ND meters that have been in service over 25 years have a greater likelihood of poor accuracy at the minimum recommended flow rate (Q^min) of 0.25 gallons per minute (gpm) (57 liters per hour (L/h)) and 0.5 gpm (114 L/h) independent of TP, and 2) comparison with data from accelerated laboratory testing showed that simulated use may not necessarily reflect the actual performance of ND meters in service, particularly, at 0.25 and 0.5 gpm. Chapter 3 is an experimental study that investigates REs of ND meters below the minimum recommended flow rate (Q^min = 0.25 gpm), particularly, at ½, ¼ and ⅛ of Q^min. Over 100 meters removed from service were tested in this study. Key findings of this study are 1) confirmed how performance decreases with reducing flow rate below Q^min, 2) of the variables considered, TP was found to be a better indicator of RE at Q_(1/8)^min up to an approximate meter reading of 0.66 MG (2.5 ML) compared to ST for 10 ≤ ST ≤ 24 years, with minimal influence at Q_(1/4)^min and none at Q_(1/2)^min, and 3) a strong linear relationship was found between RE at Q_(1/2)^min and RE at Q^min independent of TP or ST. Chapter 4 is a study that evaluates the extent to which the implementation of a new AMI system combined with a system-wide installation of new ND meters impacted the volume of MW from residential service connections of a 22,000-person municipality in southwest Virginia. Time-series analysis techniques were employed to evaluate changes in the trend of bimonthly MW and median daily MW over a six-year period. Key findings of this study are 1) the AMI system improved the accountability of MW for the utility, 2) despite an ongoing downward annual trend in MW, average bimonthly MW mildly increased after the AMI system was fully operational, and 3) annual MW increased by 2.2% in the 12-month period immediately following the metering infrastructure upgrade. / Doctor of Philosophy / An expectation of this dissertation is that it will help water utilities to have a better idea of the volume of water not being measured by residential water meters in their system (i.e., registration error) and provide insights into the effects of replacing water meters and installing automatic data collections systems (i.e., metering infrastructure upgrades) to improve accounting of water and revenue. To achieve these goals three studies were conducted. In the first two studies, over 400 nutating-disc (ND) water meters, a type of mechanical meter used to measure water, were removed from service and tested to evaluate the percent of water not measured at different ranges of flow (volume per time), and to determine if metering errors changed depending on the service time (ST) of the meter or total volume of water that had gone through (TP) it while in service. The third study consisted in the review of water consumption data from a municipality in southwest Virginia that underwent a metering infrastructure upgrade consisting of replacing all their water meters and installing an advanced metering infrastructure (AMI) system (i.e., automatic meter reading). Key findings discussed in this dissertation are 1) confirmed how performance of ND meters decreases with reducing flow rate below 0.25 gallons per minute (gpm). This is the minimum flow rate (Q^min) recommended by the U.S. water industry for accuracy testing of mechanical meters. 2) ND meters that have been in service over 25 years have a greater likelihood of poor accuracy at Q^min and 0.5 gpm independent of TP. 3) The relative influence of TP and ST on accuracy varied with the test flow rate. 4) Comparison with data from accelerated laboratory testing showed that simulated use may not necessarily reflect the actual performance of ND meters in service, particularly, at 0.25 and 0.5 gpm. 5) The AMI system improved the accountability of water for the utility. 6) Despite an ongoing downward annual trend in metered water (MW), average bimonthly MW mildly increased after the AMI system was fully operational. And 7) annual MW increased by 2.2% in the 12-month period immediately following the metering infrastructure upgrade.

This thesis addresses the innovation of information systems in enterprises, particularly in the utility market segment. The thesis starts with a definition of utilities, a market segment containing companies involved in generation, transmission, distribution and retail of energy services as well as other companies providing related networked services. The aims of this thesis are both theoretical and practical. The theoretical part offers a new theory for IS innovations for the selected segment and for the relation between the innovation and the architectures of IS. In the practical part, the author identifies current challenges and opportunities in the selected market segment and offers scenarios and visions for future development. The first part of the thesis maps out the general innovation theories in the context of the selected topic. The second part introduces a new innovation theory based on an analysis of the specific conditions in the utility market segment. The next section focuses on the topic of IS architecture and its ability for tracking and managing the changes of the IS during the innovation process. The following part relays designs for specific architecture models supporting the current innovation trends in the utility market. The final part of the thesis summarizes particular business recommendations for innovation procedures in utilities, identifies innovation opportunities, and inspires visions for the future development of the market. The opportunities are related to a new way of understanding the role of IS in utility companies. IS provides a portfolio of information services to support the customer oriented business services, advanced services with added value and tailor made services for specific customer groups.

In this research, the four valve independent metering configuration is to be investigated. The Independent metering concept will be emphasized and compared to spool valve coupled metering conventional technologies. Research focuses on the energy savings potential of the four valve independent metering configuration in addition to improving performance. The basic model of interest in this research is an actuator that is controlled by the four valve independent metering configuration to move beam like members of mobile hydraulic equipment such as tractor loader backhoes, excavators, and telehandlers. Five distinct (or discrete) metering modes that exist in the literature are initially studied: Powered Extension, High Side Regeneration Extension, Low Side Regeneration Extension, Powered Retraction, and Low Side Regeneration Retraction. The energy saving potential of these modes is studied and comparisons between this system and a conventional spool valve controlled actuator are conducted. The problem of switching between these five modes is treated as an optimal control problem of a switched dynamic system. Before solving the optimal control problem, a dynamic model for the system of interest is first derived. The model is experimentally validated. General theory for the optimal control problem is derived and then applied to the hydraulic system of interest. The results are then interpreted and explained by looking into the force-speed capability of modes. The effect of mode switching on system performance is studied as well. The basic mechanical system used for this analysis is a continuous rotating beam that undergoes structural vibrations due to mode switching in the driving hydraulic actuator. A fully coupled actuator-beam model is investigated. A non-dimensional analysis is pursued to generalize the study results. The optimal switching analysis and the vibrational study lead to the idea of Continuously Variable Modes (CVMs). Instead of having five distinct modes that determines the flow path by opening two of the four valves in the assembly, three Continuously Variable Modes are presented as an alternative way of controlling the four-valve configuration. These three CVMs combine the distinct modes and use three of the four valves to provide the fluid flow path. The five distinct modes become a special case of these three CVMs. It is going to be shown that CVMs have more force-speed capabilities than the distinct modes and provide for better velocity and vibrational performance by virtue of always offering a continuous flow path. The theory behind CVMs is presented and experimental validation follows.

This thesis presents a solution enabling lower losses in hydraulic actuator systems. A mobile fluid power system often contains several different actuators supplied with a single load sensing pump. One of the main advantages is the need of only one system pump. This makes the fluid power system compact and cost-effective. A hydraulic load often consists of two ports, e.g. motors and cylinders. Such loads have traditionally been controlled by a valve that controls these ports by one single control signal, namely the position of the spool in a control valve. In this kind of valve, the inlet (meter-in) and outlet (meter-out) orifices are mechanically connected. The mechanical connection makes the system robust and easy to control, at the same time as the system lacks flexibility. Some of the main drawbacks are The fixed relation between the inlet and outlet orifices in most applications produce too much throttling at the outlet orifice under most operating conditions. This makes the system inefficient. The flow directions are fixed for a given spool position; therefore, no energy recuperation and/or regeneration ability is available. In this thesis a novel system idea enabling, for example, recuperation and regeneration is presented. Recuperation is when flow is taken from a tank, pressurized by external loads, and then fed back into the pump line. Regeneration is when either cylinder chambers (or motor ports) are connected to the pump line. Only one system pump is needed. Pressure compensated (load independent), bidirectional, poppet valves are proposed and utilized. The novel system presented in this thesis needs only a position sensor on each compensator spool. This simple sensor is also suitable for identification of mode switches, e.g. between normal, differential and regenerative modes. Patent pending. The balance of where to put the functionality (hardware and/or software) makes it possible to manoeuvre the system with maintained speed control in the case of sensor failure. The main reason is that the novel system does not need pressure transducers for flow determination. Some features of the novel system: Mode switches The mode switches are accomplished without knowledge about the pressures in the system Throttle losses With the new system approach, choice of control and measure signals, the throttle losses at the control valves are reduced Smooth mode switches The system will switch to regenerative mode automatically in a smooth manner when possible Use energy stored in the loads The load, e.g. a cylinder, is able to be used as a motor when possible, enabling the system to recuperate overrun loads The system and its components are described together with the control algorithms that enable energy efficient operation. Measurements from a real application are also presented in the thesis.

Freeway merging VISSIM calibration techniques were developed for the analysis of ramp metering in Georgia. An analysis of VISSIM’s advanced merging and cooperative lane change settings was undertaken to determine their effects on merging behavior. Another analysis was performed to determine the effects of the safety reduction factor and the maximum deceleration for cooperative braking parameter on the simulated merging behavior. Results indicated that having both the advanced merging and cooperative lane change setting active produced the best results and that the safety reduction factor had more influence on the merging behavior than the maximum deceleration for cooperative braking parameter. Results also indicated that the on-ramp experienced unrealistic congestion when on-ramp traffic was unable to immediately find an acceptable gap when entering the acceleration lane. These vehicles would form a queue at the end of the acceleration lane and then be unable to merge into the freeway lane due to the speed differential between the freeway and the queued ramp traffic. An Incremental Desired Speed algorithm was developed to maintain an acceptable speed differential between the merging traffic and the freeway traffic. The Incremental Desired Speed algorithm resulted in a smoother merging behavior. Lastly, a ramp meter was introduced and an increase in both the freeway throughput and overall speeds was found. Implications of these findings on the future research is discussed.