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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
391

Metodologia para aferição da ação de controle proporcional integral derivativa implementada em controladores industriais. / Methodology for gauging of the action of proportional integral derivative control implemented in industrial controllers.

Shirahige, Alessandro Barbosa 07 November 2007 (has links)
Uma das atribuições da engenharia de automação é o desenvolvimento de solução de automação e controle de processos contínuos industriais. Para tanto, a principal ferramenta emprega para este controle é a ação de controle Proporcional-Integral-Derivativo (PID). Nas últimas décadas diversas empresas fabricantes de equipamentos de automação industrial têm desenvolvido e aprimorado seus controladores industriais. Estes, além de realizarem o controle de processo por lógica de intertravamento, também possuem a ação de controle PID com a finalidade de executar o controle de processo contínuo como controle de velocidade, controle de pressão, controle de nível, etc. Porém, devido a grande variedade de controladores industriais por conseqüência, a grande variedade de implementações instrução PID, implica, muitas vezes, em falta padronização da programação e operação do algoritmo da equação PID implementados nos mais diversos controladores industriais. Tal fato dificulta a engenharia de automação industrial em desenvolver controle de processos contínuos através de instruções PID. Este trabalho de pesquisa aborda o desenvolvimento de metodologia \"MAFPID\" como ferramenta de engenharia de automação para aferir o funcionamento da instrução de controle PID implementada em equipamentos de controle e automação. Esta metodologia é constituída de três Etapas de testes. A primeira Etapa constitui o estudo do equipamento testado a partir das documentações fornecidas pelo fabricante. A segunda Etapa constitui de teste dos parâmetros proporcional, integral e derivativo, realizados no controlador industrial isolado de qualquer processo. A terceira Etapa constitui de teste do controlador interagindo com um circuito analógico. Este circuito simula o comportamento de alguns processos industriais, fornecendo ao controlador aferido sinais de entradas e de saída semelhantes aos processos reais. Este trabalho também apresenta dois estudos de caso, nos quais foi aplicada a metodologia MAFPID. / One of attributions of the automation engineering is the development of automation solution and control of industrial continuous processes. For in such a way, the main tool uses for this control is the action of Proportional-Integral-Derivative control (PID). In the last diverse decades companies equipment manufacturers of industrial automation have developed and improved its industrial controllers. These, besides carrying through the control of process for interlocking logic, also possess the action of control PID with the purpose to execute the control of continuous process as control of speed, control of pressure, control of level, etc. However, due to great variety of industrial controllers for consequence, the great variety of implementations instruction PID, it implies in lack standardization of the programming and operation of the algorithm of equation PID implemented in the most diverse industrial controllers. Such fact, it makes difficult the engineering of industrial automation in developing control of continuous processes through instructions PID. This work of research approaches the development of methodology MAFPID as tool of engineering of automation to survey the functioning of the instruction of control PID implemented in control equipment and automation. This methodology is constituted of three stages of tests. The first stage constitutes the study of the equipment tested from the documentations supplied for the manufacturer. The second stage constitutes of test of the parameters proportional, integral and derivative, carried through in the isolated industrial controller of any process. The third stage constitutes of test of the controller interacting with an analogical circuit. This circuit simulates the behavior of some industrial processes, supplying signals of input and output to the surveyed controller of similar to the real processes. This work also presents two studies of case, in which was applied methodology MAFPID.
392

Implementation of an office information system for the Department of Computer Science

Anderson, John Scott January 2010 (has links)
Typescript (photocopy) / Digitized by Kansas Correctional Industries
393

Automating the Detection of Precipitation and Wind Characteristics in Navy Ocean Acoustic Data

Kuhner, Joseph T 20 December 2018 (has links)
A challenge in Underwater Acoustics is identifying the independent variables associated with an environment’s ambient noise. A strict definition of ambient noise would focus on non-transient signatures and exclude transient impacts from marine mammals, pelagic fish species, man-made sources, or weather events such as precipitation or wind speeds. Recognizing transient signatures in acoustic spectra is an essential element for providing environmental intelligence to the U.S. Navy, specifically the acoustic signatures from meteorological events. While weather event detection in acoustic spectra has been shown in previous studies, leveraging these concepts via U.S. Navy assets is largely an unknown. Environmental intelligence collection can be improved by detecting precipitation events and establishing wind velocities with acoustic signatures. This will further improve meteorological models by enabling validation from both manned and unmanned sub-surface assets.
394

THE PERSONAL COMPUTER AND THE PUBLIC LIBRARY: A STUDY OF THE ABSORPTION OF NEW TECHNOLOGY AND AN ANALYSIS OF LIBRARIAN'S OPINIONS ABOUT THE PRESENT AND FUTURE IMPACT ON AUSTRALIAN PUBLIC LIBRARIES

Willard, Patricia, School of Librarianship, UNSW January 1989 (has links)
The social impacts of new information technology have attracted much attention in recent years. This study looked at the personal computer's impact on the public library's services and functions. Particular attention was paid to the public access personal computer. The method involved a Baseline survey to establish the availability and use of public access personal computers in Australian public libraries and a Delphi survey to consider possible futures. The researcher's framework was drawn from reviews of the literatures on futures research; new information technology and its social impacts; the development and current situation of the public library; and innovation research. The Baseline survey revealed that public access personal computers were becoming increasingly common in public libraries, though their provision was not yet widespread. Existing and planned uses included games, literacy and various other educational activities. Overall the public access personal computer was viewed as a favourable innovation with the part it could play in developing community computer literacy receiving particular attention. The Delphi panel was comprised of 25 public librarians selected on the basis of their knowledge about computers in public libraries. The 41 Event Statements postulated a wide range of changes in - (1) the nature and method of service provision; (2) the patterns of client demand and use; and, (3) financial allocations. The results revealed greater variability of opinion about the likely time of occurrence of the Events than about their desirability. A high level of opinion change between the two Rounds did not produce much movement toward consensus - indicating that the panel had varied views of the future. Comment on both surveys indicated that the librarians were keen to develop services relevant to their communities and if public access personal computers were such a service they would strive to provide them. The Delphi survey proved a good vehicle for encouraging consideration of the future and further research using the method seems warranted.
395

Domain Specialisation and Applications of Model-Based Testing

Pari-Salas, Percy Antonio Unknown Date (has links)
Software testing, one of the most important methods for quality assurance, has become too expensive and error prone for complex modern software systems. Test automation aims to reduce the costs of software testing and to improve its reliability. Despite advances in test automation, there are some domains for which automation seems to be difficult, for example, testing software to reveal the presence of security vulnerabilities, testing for conformance to security properties that traverse several functionalities of an application such as privacy policies, and testing asynchronous concurrent systems. Although there are research works that aim to solve the problems of test automation for these domains, there is still a gap between the practice and the state of the art. These works describe specific approaches that deal with particular problems, generally under restricted conditions. Nevertheless, individually, they have not made noticeable impact on the practice in test automation for these domains. Therefore, there is a need for an integrated framework that binds specific approaches together in order to provide more complete solutions. It is also important for this framework to show how current test automation efforts, tools and frameworks, can be reused. This thesis addresses this need by describing a general model-based testing framework and its specialisation for the testing domains of security vulnerabilities, privacy policies and asynchronous systems
396

Lean automation : Riktlinjer för arbete med robotceller i ett lean produktionssystem

Samuelsson, Maria, Lundgren, Micaela January 2007 (has links)
<p>THIS PAPER IS BASED on thesis work done at Volvo CE Component</p><p>Division in Eskilstuna, from April to October 2007. The thesis work</p><p>considered industrial robots within lean production. The purpose was to</p><p>come up with guidelines on how to work with industrial robots and</p><p>design productions cells in a lean environment. The authors have used</p><p>various techniques e.g. literature study, study visit and interviews to reach</p><p>their result. First the authors tried to make a picture of and define lean</p><p>automation and then they wanted to compare that picture with the</p><p>present state of the factory. The purpose was to limit the thesis work to</p><p>the part of automation that is built by industrial robots and therefore only</p><p>this type of automation is considered in the current state analysis. The</p><p>authors consider that a holistic view and a stable foundation are the most</p><p>important things to start to work with lean automation. The result that is</p><p>presented in this thesis is most of the times far from specific for the design</p><p>of the individual cells since the authors felt it more important to focus on</p><p>building the right environment for lean automation. The easiest and</p><p>quickest way to summarize the work is the guidelines that are based on</p><p>the current state analysis made at CE Component Division and the</p><p>authors’ definition of lean automation. The purpose of the guidelines are</p><p>to give Component a picture of how to work to create clearer directives</p><p>when, where and how much the company wishes to implement</p><p>automation. At the same time they are also meant to help build a structure</p><p>for work with maintenance, internal transports, packaging etc. The paper</p><p>also presents a way to work as well as a suggestion on how to work with</p><p>building an individual cell could be conducted.</p> / <p>DEN HÄR RAPPORTEN BYGGER på ett examensarbete som utfördes på</p><p>Volvo CE Component Division i Eskilstuna från april till oktober 2007.</p><p>Examensarbetet behandlade området industrirobotar i ett lean</p><p>produktionssystem och hade som syfte att komma med riktlinjer på hur</p><p>arbetet med industrirobotar bör bedrivas och robotceller designas i en lean</p><p>produktionsmiljö. Författarna har använt sig av ett antal olika sätt, bl.a.</p><p>litteraturstudier, studiebesök och intervjuer för att komma fram till sitt</p><p>resultat. Först försökte författarna göra sig en bild av och definiera lean</p><p>automation för att sedan jämföra den bilden med situationen i fabriken.</p><p>Utgångspunkten var att begränsa arbetet till den del av automationen som</p><p>är uppbyggd med industrirobotar och i nulägesanalysen kartlades därför</p><p>endast de celler som innehåller industrirobotar. Författarna anser att för</p><p>att arbeta med lean automation är helheten och grunden det viktigaste.</p><p>Det resultat som presenteras i den här rapporten koncentrerades därför</p><p>kring att skapa förutsättningarna för lean automation. Arbetet kan enklast,</p><p>snabbast sammanfattas i de riktlinjerna som togs fram utifrån</p><p>nulägesanalysen och definitionen av lean automation. Riktlinjerna är</p><p>tänkta att ge Component en bild på hur de bör arbeta för att skapa klarare</p><p>direktiv när, var och hur mycket företaget önskar att automatisera.</p><p>Samtidigt som de även är tänkta att bygga upp en struktur för arbete med</p><p>underhåll, interna transporter, emballage etc. Rapporten presenterar även</p><p>ett tänkt arbetssätt samt förslag på hur arbetet med att utforma den</p><p>enskilda cellen bör bedrivas.</p>
397

Automatiserad produktionscell för lasersvetsning av fläkthus i titan

Lindblom, Anna, Wennberg, Frida January 2007 (has links)
<p>För att vara framgångsrik i dagens tillverkningsindustri gäller det att vara konkurrenskraftig och komma med nya tillverkningssätt. Därför satsar Volvo Aero på lasersvetsning och automation. På Aero-Craft i USA grovbearbetas fläkthus i titan. Fläkthusets diameter är cirka tre meter och dess bakre del sätts idag samman från tre delar med hjälp av skruvförband och plasmasvets. Volvo Aero vill lasersvetsa dessa delar istället. En studie har därför påbörjats som skall visa hur en produktionscell för lasersvetsning skulle kunna se ut och fungera. Svetsarna är alla av typen stumsvetsar och det som skall svetsas är tre axiella skarvar, två rundskarvar och fastsvetsning av ett växellådsfäste. Innan svetsning häftsvetsas delarna först ihop och 3D-skanner används för inspektion. Efter att svetsen svalnat kontrolleras rundskarvarna av en digitalröntgen. Allt skall ske i produktionscellen. Resultatet presenterar en produktionscell uppdelad i två rum. Det första rummet är laserskyddat, och där utförs svetsning av axiella skarvar och växellådsfäste. Ett hål laserskärs ut där växellådsfästet skall sitta. Det andra rummet är både röntgen- och laserskyddat och där svetsas rundskarvar. En fogföljare med laserdiod och kamera används under svetsprocessen för att rikta laserstrålen efter skarven. I rum ett finns en processrobot och en hanteringsrobot och i rum två en processrobot. Fixturerna som presenteras i rapporten är endast konceptuella. Antalet fixturer är en till rum ett och två likadana till rum två. Fixtureringen i rum två utgörs av en expanderfixtur med rotgasbackar i aluminium. På Volvo Aero används vanligen expanderfixturer vid svetsning, men de har aldrig gjorts i den storlek som krävs för fläkthuset. Krav som ställs på manipulator är att den skall klara detaljens och fixturens vikt, samt att den skall klara uppsatta svetstoleranser.</p>
398

EPROCUREMENT INNOVATIONS IN ORGANIZATIONS : REASONS FOR IMPLEMENTATION AND OUTCOMES

Pacheco, Edder, Martinez, Diego January 2009 (has links)
Nowadays, companies are facing several competitive pressures, which push them to seek for new and better ways to conduct their internal processes. One of this ways is throughout processes innovations that allow the company to establish and maintain competitive advantages; one example of this new trend is the emergence of eProcurement, an electronic system aimed to automate purchasing processes in organizations, which, if it is properly implemented, will derive in processes cost reduction and efficiency improvement on those same procedures. This study is focused on identifying the propeller factors that make companies to engage in this kind of ventures; as well as studying which are the outcomes generated inside the organizations once the electronic system has been implemented. Purpose The purpose of this thesis is to identify the elements that trigger automation of procurement processes in organizations; as well as describing the implications derived from automation during and after such implementation. The study was conducted through interviews with managers and final user from two Mexican companies which are currently using Oracle as their eProcurement tool. Conclusions The study found that depending on how well organizations prepare themselves and their staff for the upcoming change, different results may be obtained in terms of benefits and acceptability from final users. In order to avoid potential pitfalls, firms must bear in mind that, both operational and social awareness are key factors for a successful implementation. If a company takes into consideration their internal operational needs and staff opinions to base their decision of engaging on eProcurement, it will be more likely to obtain benefits related to cost reduction, improved efficiency and final user satisfaction.
399

Process control and instrumentation methods for biomass fluidized bed gasifier operation

Campbell, William Allan 04 June 2010
A fluidized bed gasification (FBG) pilot plant was designed and constructed at the University of Saskatchewan Chemical Engineering Department Fluidization Laboratory. FBG is a thermo-chemical method for converting solid biomass to a gaseous fuel, termed syngas. Several instrumentation and control issues were particularly challenging with this pilot plant, including development of the fuel feeding system, pressure measurement of high temperature fluids, and metering of steam as a process reactant.<p> The fuel feeding system was tested using MBM (meat and bone meal) to determine the output rate stability, and predictability and measurability of the system as the components in the fuel feeding system were integrated. The fuel feeding system that was tested included a 150 mm primary metering screw conveyor, a 150 mm rotary airlock, and a 50 mm secondary injection screw conveyor. Each component of the system was fitted with a 3-phase electric motor and a variable speed drive to allow for a variable output rate. The weighing system that was integral to the metering conveyor was tested as well, but upon pressurizing the metering conveyor and hopper, the weighing system sustained an unreasonable amount of noise. Integrating a pneumatic injection nozzle with the injection conveyor was found to work effectively both under ambient temperatures and hot FBG conditions up to 725oC. Above 725oC, it was found that the test fuel would char and coat the nozzle, causing it to plug. Testing of the feeding system with the injection nozzle removed illustrated that the system could work well without it. It was determined that the injection conveyor speed to metering conveyor speed ratio that should be used for this system was 1:110 for absolute rotational speeds, or 1:1 of the full conveyor speeds. The complete system, including the injection nozzle, was analyzed and determined to produce a fuel output rate (FS) for % speeds from 5-25%, which roughly corresponded to the desired plant fuel feed rate of 1-5 g/s.<p> Techniques for remote pressure measurement of fluidized beds were examined as well, including the use of long tubes to cool hot gases and filters for blocking solid particles. The pressure measurement delay of these techniques was examined in comparison to a direct local measurement. This was conducted by comparing the pressure readings from two identical sensors; one mounted directly to a manifold, and the other mounted via a variable assembly (comprised of a variable length of 6.35 mm (1/4") PE tubing and a porous plate filter). Assemblies without a porous plate were found to have a minimal delay of up to 0.303 seconds for 30 m length of PE impulse tubing. More significant delays were found for systems using both a 10 media grade porous plate filter and impulse tubing; a 3 m tube length with filter has a delay of up to 0.221 s, and a 30 m impulse tube combined with the filter has a measurement delay of up to 1.915 s, a significant delay in cases where high-frequency analysis of pressure is used for bed agglomeration prediction, or systems where fast response is required to changing pressure conditions.<p> Additionally, a steam flow measurement system using an orifice plate and differential pressure sensor was installed and calibrated. By collecting time-based steam samples and process data, the physical system coefficients were determined for this system, allowing for steam flow measurement, accurate within 5% over a flow range of 0.5 to 2.0 g/s.
400

Framtagning av en utvecklingsprocess för automation - baserat på konceptet Lean Automation

Carnbo, Linda January 2012 (has links)
Due to the globalization today the competition in the market has in- creased and it requires flexibility and produce according to customer demand. In order to reduce the cost of wages industrial companies are now considering moving the manufacturing to low-cost countries. To keep up with the competition in the market without moving the manu- facturing abroad, Lean Automation was developed. The concept of Lean Automation is to reduce the perceived complexity with automa- tion and make automation available for new users and in new applica- tions. Haldex Brake Products are situated in Sweden and want to maintain the manufacturing of the automatic brake adjusters in the country. It is a product well-known and highly exposed to the competition in the mar- ket. Due to this situation Haldex are collaborating with Mälardalen University to develop a robotic cell based on the concept of Lean Au- tomation. It will be installed on their assembly line in 2012. The goal with this master thesis is to create a development process for automation, which can enable the company to be more competitive in the market and this by using their own knowledge to develop automat- ed solutions for higher efficiency in the production line. In addition to the development process for automation, programming of the Lean Au- tomation robotic cell is to be conducted. The conducted work in the master thesis was the programming of the robotic cell and the development process for automation. The pro- gramming was made Lean by reducing waste of time when working with the programmed code. This by a clear structure in the program- ming which makes it easy to handle. A development process for auto- mation was made and used for developing a robotic cell for the assem- bly line. The robotic cell was then tested at Haldex, an important stage before implementing the cell on the assembly line. Testing the robotic cell will give important information about how the equipment actually runs and failures can be observed and adjusted. Testing of the robotic cell will continue after the end of this master thesis.

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