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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.
81

An?lise de desempenho de algoritmos de compress?o de dados com perda para aplica??es industriais

Medeiros Neto, Edson Jackson de 09 November 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-03T23:48:41Z No. of bitstreams: 1 EdsonJacksonDeMedeirosNeto_DISSERT.pdf: 2349422 bytes, checksum: 58dbff032ce7a77c69ab57cce418be2d (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-07T19:55:39Z (GMT) No. of bitstreams: 1 EdsonJacksonDeMedeirosNeto_DISSERT.pdf: 2349422 bytes, checksum: 58dbff032ce7a77c69ab57cce418be2d (MD5) / Made available in DSpace on 2016-06-07T19:55:39Z (GMT). No. of bitstreams: 1 EdsonJacksonDeMedeirosNeto_DISSERT.pdf: 2349422 bytes, checksum: 58dbff032ce7a77c69ab57cce418be2d (MD5) Previous issue date: 2015-11-09 / O grande volume de dados gerados como resultado da supervis?o de processos de automa??o na ind?stria gerou como consequ?ncia um vasto espa?o de armazenamento em disco, assim como dificuldade na transmiss?o destes dados por links de telecomunica??es. Os algoritmos de compress?o com perda de dados surgiram na d?cada de 90 com intuito de solucionar estes problemas, passando a serem utilizados em sistemas de supervis?o industrial para a compress?o de dados em tempo real. Para isso estes foram projetados para eliminar informa??es redundantes e indesejadas de forma simples e eficiente. No entanto, os par?metros destes algoritmos necessitam de serem configurados para cada vari?vel de processo, tornando invi?vel a configura??o manual em caso de sistemas que supervisionam milhares de vari?veis. Nesse contexto este trabalho prop?e o algoritmo Adaptive Swinging Door Trending, que consiste numa adapta??o do Swinging Door Trending, em que seus principais par?metros s?o ajustados dinamicamente atrav?s da an?lise de tend?ncias do sinal. Prop?e-se tamb?m uma an?lise comparativa de desempenho dos algoritmos de compress?o com perda de dados aplicados sobre vari?veis de processo de s?ries temporais e cartas dinamom?tricas de fundo de po?o. Os algoritmos abordados para efeito comparativos foram os lineares por partes e os de transformadas. / The great amount of data generated as the result of the automation and process supervision in industry implies in two problems: a big demand of storage in discs and the difficulty in streaming this data through a telecommunications link. The lossy data compression algorithms were born in the 90?s with the goal of solving these problems and, by consequence, industries started to use those algorithms in industrial supervision systems to compress data in real time. These algorithms were projected to eliminate redundant and undesired information in a efficient and simple way. However, those algorithms parameters must be set for each process variable, becoming impracticable to configure this parameters for each variable in case of systems that monitor thousands of them. In that context, this paper propose the algorithm Adaptive Swinging Door Trending that consists in a adaptation of the Swinging Door Trending, as this main parameters are adjusted dynamically by the analysis of the signal tendencies in real time. It?s also proposed a comparative analysis of performance in lossy data compression algorithms applied on time series process variables and dynamometer cards. The algorithms used to compare were the piecewise linear and the transforms.
82

[pt] AVALIAÇÃO DAS CONDIÇÕES DE ESTABILIDADE DE TENSÃO CONSIDERANDO A ATUAÇÃO DA REGULAÇÃO PRIMÁRIA E SECUNDÁRIA / [en] EVALUATION OF THE VOLTAGE STABILITY CONDITIONS CONSIDERING THE ACTING OF THE PRIMARY AND SECONDARY FREQUENCY CONTROL

MAXWELL ABRAHAN VARGAS CARBAJAL 02 February 2016 (has links)
[pt] Cada dia a operação dos sistemas elétricos de energia é mais complexo. Mantiver um correto fornecimento da energia de forma empírica é uma tarefa difícil e pouco confiável, este trabalho se realizou para ajudar a atender com maior confiabilidade este fornecimento de energia. Neste trabalho apresentam-se modelagens de fluxo de carga para obter diferentes pontos de operação. Modelou-se a regulação própria da carga e o controle carga-frequência das unidades geradoras, incluindo regulação primária e secundária. As modelagens são estendidas para a avaliação da estabilidade de tensão, inclusive considerando-se a influência da frequência. A avaliação foi feita em pontos de operação antes e após a atuação do controle carga-frequência. Em cada caso, as variações de carga ou geração das barras em análise (infinitesimais) são absorvidas pelos geradores de diferentes formas: de acordo com os fatores de proporcionalidade na regulação secundária, com as energias de regulação na regulação primária ou com a proporcionalidade das gerações das barras swing no despacho proporcional. De acordo com o apresentado neste trabalho obtêm-se pontos de operação em regime permanente, nestes pontos de operação foi onde se realizo o cálculo da estabilidade de tensão para todas as barras do sistema. Os sistemas testados tiveram 6 e 39 barras. / [en] Each day the operation of electric power system is more complex. Maintain a correct supply of energy empirically is difficult and unreliable task, this work was realized to comply with more reliably this power supply. This dissertation presents the modeling of power flow to get different steady state. The load response to frequency deviation, the primary and the secondary frequency control were models. The models are extended to the evaluation of voltage stability, even considering the frequency influence. The evaluation is done in the state before and after the response of load-frequency control. In each case, the generators units absorb the variation (infinitesimal) in the load or in the generation (bus in analysis) in different ways: according to the proportionality factor in the secondary control, the speed regulations in the primary control or the proportionality of the swing bus generation in the proportional dispatch. According to the presented in this dissertation was obtained a state in permanent regime, in this state was evaluated the voltage stability in all bus of the system. The tested system had 6 and 39 bus.
83

Hanging Load Mock-Up For Experimental Setup To Test Flight System Stability

Gundstedt, Anthony January 2023 (has links)
Can we reduce disturbance, swing, and errors by delegating some of the tasks to a subsystem on the tool hanging from a drone to gain precision and dependability? This project covers developing and implementing a user-controlled prototype with an automatic control system and gripper for functionality and controlled movement in 5 DOF. AirForestry is developing a new way of working in the forestry business to provide a greener and healthier solution for the soil and the environment. The forestry industry emits approximately one million tons of CO2 per year from heavy diesel-fueled vehicles. With a renewable energy battery-powered drone of a diameter of 6.2 m and a hanging harvesting tool, they can significantly improve the environmental impact of forestry. The harvesting tool has an automatic control system and is user controlled to perform the thinning and cutting of trees. The main focus is to use IMU sensor data to produce accurate angle estimation to control the stability of a scaled prototype and to implement physical restrictions to make it able to be attached safely and tested on a drone but not limit the controlled mobility of the prototype with a system independent of the control system of the drone itself. The user can control the attitude and elevation and receive real-time sensor data wireless during operation. With the intended spacing of the attachment points on the drone, it can prevent unwanted swing from a push or displaced drop. It uses the accelerometer on the IMUsensor to calculate the angle of roll and pitch, although the accelerometer is sensitive to vibrations and rotations. The control system has a fast response and rise time, but it experiences noise and oscillations. Sensor fusion of the accelerometer and gyroscope in a complementary filter can be implemented to increase the accuracy of the angle estimations and decrease the noise, which will be reflected in the speed of the servos and thereby improve the stability and mobility of the system.
84

The correlation between passive and dynamic rotation in both the lead and trail hips of healthy young adult male golfers during a golf swing

Alderslade, Villene 04 1900 (has links)
Thesis (MScPhysio)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Introduction-The golf swing is a complex, sequenced movement of body segments. This movement is smooth and well timed and is referred to as the kinematic golf sequence. This kinematic sequence illustrates the rotational speed, which occurs between the upper and lower body segments. Hip rotation plays an integral part to a sound kinematic sequence by providing a pivotal point between the upper and lower body segments, ensuring a synchronised golf swing. Hip rotation kinematics during a golf swing has received relatively little attention compared to other body segments’ movements. However, clinicians need to have a clear understanding of the rotational contribution that each hip make during golf swing in order to enhance the athlete’s performance and reduce the risk of injury. The aim of this descriptive research project was to obtain and investigate the total passive and total dynamic rotation range of movement in both the lead and trail hips of healthy, young adult, male golfers. Methodology-Seven, low handicapped, male golfers between the ages of 18 and 40 years were randomly selected in the Western Cape region from areas surrounding Stellenbosch University’s Tygerberg campus. A questionnaire gathered participant demographics that determined participatory eligibility. A preliminary reliability study established a baseline measurement for passive total articular hip rotation. Seatadjusted total passive hip rotation ranges of motion (ROM) measurements were collected with a hand-held inclinometer. Dynamic total hip rotation kinematic data was captured during a golf swing with an 8-camera video analysis system (VICON). Data analyses were performed with Statistica version 10. Hand-held inclinometer intra-rater reliability was determined with a two-way interclass correlation, standard error of measurement and a 95% confidence interval level. A Spearman correlation coefficient determined correlation between the total passive and total dynamic rotation range of movement in both the lead and trail hips. Results-Passive intra-rater reliability was reported as 0.81 (95% CI: 0.46-0.96). The total average passive articular range between the lead (62.1° ±6.4°) and trail hip (61.4° ±3.8°) did not report any significant difference (p=0.8). The total average dynamic golf swing articular range between the lead (29° ± 6.5°) and trail hip (35.° ±7.8°), was reported as significantly (p=0.04) asymmetric. The findings also demonstrated a positive correlation between the passive and dynamic total articular range in a lead hip, whereas a negative correlation was reported in a trail hip. During the golf swing the lead hip utilised 46.4%(± 8) of the total passive available hip rotation, whereas the trail hip utilised 58.8% (±13.2). Discussion and Conclusions-The findings of this study show that, the passive rotation ROM in a hip (LH=62°; TH=61°) of a golf player does not exceed the available range it has during a golf swing. The golfer’s hip utilises 46% of the available passive range of movement in the lead hip and 59% in the trail hip. In the clinical field careful consideration should be given to the motivation behind mobilizing, treating or stretching the hips of a golf player. These findings can be incorporated in future research on the relationship between hip-rotation ROM and reduction in the incidence of injuries amongst golfers. / AFRIKAANSE OPSOMMING: Inleiding-Die gholfswaai is n komplekse, opeenvolgende beweging van verskeie liggaamsegmente. Hierdie gladde opeenvolgende bewegings word die kinematiese gholfpatron genoem. Hierdie kinematiese opeenvolgende bewegings bied ’n illustrastrasie van die rotasiespoed waarteen die beweging tussen die boonste en onderste liggaamsegmente plaasvind. Heuprotasie speel ’n deurslaggewende rol in hierdie glad verlopende kinematiese proses. Dit dien as ’n spilpunt tussend die boonste en onderste kwadrant, wat op sy beurt weer ’n gesinkroniseerde gholfswaai verseker. Die heuprotasie kinamtieka tydens n gholfswaai het relatief minder aandag ontvang in vergelyking met ander liggaamsegmente. Klinici moet instaat gestel word om ’n duidelike begrip aangaande die bydrae wat heuprotasie tydens ’n golfswaai lewer, te ontwikkel. Die atleet se prestasie kan sodoende verbeter word, en die risiko tot beserings kan ook sodoende voorkom word. Die doel van hierdie beskrywende navorsingsprojek was om te bepaal wat die totale passiewe en die totale dinamies rotasie omvang van die leidende en volgende heupe van gesonde jong mans wat gholf speel, te ondersoek. Metodologie-Sewe gholf-geskoolde manlike gholf spelers met ’n lae voorgee en tussen die ouderdom van 18 en 40 jaar is ewekansig gekies. Hierdie kandidate is gekies uit die omliggende gebiede van die Stellenbosch Tygerberg kampus in die Wes-Kaap waar hulle relatief naby woonagtig was. ’n Vraelys is aangewend om demografiese eienskappe van elke deelnemer in te samel. Hierdie inligting wat deur die vraelys bekom is, is gebruik om te bepaal of die deelnemers in aanmerking is vir die studie. ’n Voorlopige, intra-meter betroubaarheidstudie is gedoen vir passiewe, totale artikulêre heuprotasiemetings wat met ’n hand hanteerbare hoek meter geneem is. ’n Algemene fisiese ondersoek is in die biomeganiese labaratorium afgehandel om te bepaal of die deelnemers geskik is vir die toetse. Sit-aangepaste passiewe totale hip rotasie beweging metings was ingesamel met 'n hand hanteerbare hoek meter. Intra-meter betroubaarheid is bepaal met ’n twee-rigting interklas korrelasie, standaard foutmeting en ’n 95% vertroue interval vlak. Dinamiese totale heup kinematiese rotasiedata is afgeneem met ’n hoë-spoed 3-D videografiestelsel (VICON) tydens 'n gholfswaai. Data-ontleding is bereken met ’n Statistica weergawe 10. Die gemiddelde en Spearman korrelasie koëffisiënt is gebruik as aanwysers van verspreiding. Resultate-Passiewe inter-meter betroubaarheid word geraporteer as 0.81 (95% KI: 0.46-0.96). Die resultate dui op ’n onbeduidende totale passiewe artikulêre reeks verskille tussen die leidende (voorste) (62.1 ± 6.4 °) en volgende (agterste) heupe (61.4 ° ± 3.8 °). ’n Beduidende totale dinamiese artikulêre reeks van die leidende (29 ° ± 6.5 °) en volgende heupe (35.9 ° ± 7.8 °) is tydens die gholfswaai bereik. Verdere resultate toon ’n positiewe korrelasie tussen die passiewe en dinamiese totale artikulêre reeks in die leidende heup, terwyl ’n negatiewe korrelasie gerapporteer word vir die volgende (agterste) heup. Tydens ’n gholfswaai gebruik die leidende heup 46.4% (± 8%) van die totale passiewe beskikbaar heuprotasie, terwyl die opvolgende (agterste) heup 58.8% (± 13.2%) aanwend. Bespreking en gevolgtrekking-Die bevindinge van hierdie studie toon dat tydens ’n gholfswaai, ’n gesonde gholfspeler nie die beskikbare passiewe beweging wat in sy heup bestaan oorskry nie. Slegs 46.4% van die beskikbare passiewe beweging in sy leidende heup word gebruik, en 58.8% van sy agterste heup. Die klinisie moet deeglike oorweging gegee word aan die motivering agter die mobilisering, strekke en die behandeling van die heupe van ’n gholfspeler. Hierdie bevindings kan in toekomstige navorsing geimplimenteer word om die verhouding wat tussen die omvange vand heuprotasie bestaan te ondersoek. Die voorkoming van moontlike toekomstige beserings in gholfspelers kan ook verhoed word.
85

Analytical models of single and double gate JFETs for low power applications

Chang, Jiwon, active 2013 03 September 2009 (has links)
I propose compact models of single-gate (SG) and double-gate (DG) JFETs predicting the current-voltage characteristics for both long and short channel devices. In order to make the current equation continuous through all operating conditions from subthreshold to well-above threshold, without non-physical fitting parameters, mobile carriers in depletion region are considered. For describing the short channel behavior, relevant parameters extracted from the two-dimensional analytical solution of Poisson's equation are used for modifying long channel equations. Comparisons of models with the numerical simulation showing close agreement are presented. Based on models, merits of DG JFET over SG JFET and SG MOSFET are discussed by examining the schematic circuit diagram describing the relation between gate and channel potentials for each device. / text
86

A very modern tradition : Costa Rican swing criollo as urban popular folklore

Griffith, James Brian 09 October 2014 (has links)
Over the past ten years, the Costa Rican dance style known as swing criollo has gone from relative obscurity to acceptance as national heritage. In the 1970s and 1980s, it was considered a dance of the urban working-class chusma, or "riff-raff," because of its associations with the working-class music of cumbia and San José's seedy dance salons. Starting in the early 2000s, however, an active campaign of nationalization and folklorization by dance instructors brought the dance to the status of national patrimony. This was achieved through dance classes, festival performances, the creation of a short video documentary, and the work of the dance company La Cuna del Swing to canonize the dancers and stages of swing criollo. The folklorization of swing criollo at first seems to be a top-down phenomenon that suggests little agency among working-class dancers; they have been personified in the national imaginary as exotic Others, an urban folk from an earlier generation that now exists only to perform and embody that tradition. On further examination, the folklorization of swing criollo represents a new sort of folklore, one that is highly contested and engages in a different discourse of authenticity, some influenced by dancers themselves. Swing criollo as a "modern" and "urban" form has allowed for self-mythmaking among the dancers of the self-proclaimed "old guard" that invented the style. It also legitimizes the dance style in its popular form, as opposed to older projections of folklore that that place tradition in opposition to modernity. I examine discourses surrounding the nationalization of swing criollo as well as the negotiations of spaces of culture through which swing's legitimization unfolded. I conclude by suggesting that ethnomusicologists should continue to theorize folklore's changing nature as it is contested and re-defined to include popular, urban, and modern cultural expressions. / text
87

Deklaratyviai apibrėžiamų komponentų architektūra: projektavimas ir realizacija Java sistemoje / The architecture for declarative components: design and java implementation

Valskis, Justas 04 July 2014 (has links)
Šio darbo tikslas yra sukurti metodą, kuris teiktų galimybę kuo didesnę vartotojo sąsajos dalį apibrėžti deklaratyviai (komponentų kūrimas, įvykių klausytojų registravimas, komponentų tarpusavio sąryšių apibrėžimas ir vizualus komponentų išdėstymas languose). Darbe išanalizuotos įvairios komponentinės architektūros bei išraiškingą vartotojo sąsajos apibrėžimą įgalinantys sprendimai. Apibrėžta ir įgyvendinta architektūra leidžianti kurti deklaratyviai apibrėžiamus vartotojo sąsajos komponentus, kurie deklaruoja savo elgesį ir gali bendrauti tarpusavyje pranešimų pagalba. Rezultate buvo sukurta sistema, kuri leidžia kurti taikomąsias programas su Java Swing vartotojo sąsaja, naudojantis beveik vien tik deklaratyviais taikomosios programos dalių apibrėžimais. Sukurtos sistemos konfigūracijos galimybės leidžia sumažinti komponentų manipuliacijai skirto Java kodo poreikį. / A part of a user interface can be created using declarative means. The main goal of this paper is to maximize that portion. To do that, said means would be used to create components, register event listeners, describe relationships between components and layout them in windows. Various component-based architectures and existing solutions for declarative user interface definition were analyzed. As a result, an architecture was defined which allows user interface components to be created using a declarative approach. These components define their behavior and use messages to communicate with each other. The outcome was a system, which can create Java Swing applications using mostly declarative definitions of various parts of said applications. This system provides various configuration options that reduce the need of writing Java code for component manipulation.
88

Investigation of a swing check valve using CFD

Boqvist, Emil January 2014 (has links)
This master’s thesis is made to increase the understanding of the dynamic characteristics of a typical large swing check valve used in a system that transports pressurized water to a reactor tank.3D FSI-simulations are performed for a number of transients in order to study the dynamic characteristics their dependence of the deceleration rate. The purpose is to find information about the dynamics that could be used in a future improvement of a 1D-model.Steady state simulations are performed for angles in the whole spectrum. Seven transient FSI-simulations with different constantly decelerating flows from 630 kg/s2 (6.7 m/s2) to 40 320 kg/s2 (430 m/s2) have been performed. The pressure on the disc caused by the hydraulic torque is integrated and the corresponding torque contribution, together with the weight torque, is used in the second law of motion to calculate the movement of the disc throughout the transients.Steady state simulations yield the pressure drop over the valve, which could be compared with field measurements in order to validate the CFD-simulations. Comparison of the pressure distribution on the disc for the steady state and transient simulations shows the importance of taking the disc angular velocity into account when modelling in 1D. Correlations between the angle, angular velocity, torque and mass flow are obtained from the transient FSI-simulations. Torque coefficients according to (Li & Liou, Vol. 125) are also brought out from the simulated transients, but in order to create a model in line with this approach further simulations have to be performed. A prediction of the pressure rise that occurs when a swing check valve closes in backward flow according to the Joukowsky equation is brought out and gives an idea of the loadings that the system has to be able to handle.
89

Úroveň atletických dovedností studentů střední školy / Level of athletic skills of middle school students

Tůma, Jiří January 2015 (has links)
Thepurposeofthis thesis was to determinewhethermy assembledtutorial has a positive impact on thetechniqueofthelow start and swing run. Thetheoretical part explainsthekeywordsthat are necessaryforanunderstandingoftheissues. In thepractical partwasshooted a filestudentsduring a lowstarting and swing runningthenwasappliedtheassembledtutorial to this sample ofstudents and thenwasshootedthe video again. Evaluationoftheresearchwasperformed by comparingtherecordedvideos. Thanks to thisprocedurewasfoundthe influence ofthetutorial on thetechniqueduringlowstarting and the swing phaseof run. Keywords: running, low start, swing running, athletics
90

An Automated Data Warehouse

Sharathkumar, Sudhindra 07 August 2003 (has links)
An increasing number of organizations are implementing data warehouses to strengthen their decision support systems. This comes with the challenges of the population and the periodic update of data warehouses. In this thesis, we present a tool that provides users with features to create a warehouse database and transform structures of the source database into structures for the warehouse database. It is highly interactive, easy to use, and hides the underlying complexity of manual SQL code generation from its users. Attributes from source tables can be mapped into new attributes in the warehouse database tables using aggregate functions. Then, relevant data is automatically transported from the source database to the newly created warehouse. The tool thus integrates warehouse creation, schema mapping and data population into a single generalpurpose tool. This tool has been designed as a component of the framework for an automated data warehouse being developed at theComputer Science Department, University of New Orleans. Users of this framework are the database administrators, who will also be able to synchronize updates of multiple copies of the data warehouse. Warehouse images that need to be updated are taken offline and applications that need to access the data warehouse can now access any of the other image warehouses. The Switching Application built into this framework switches between databases in a way that is totally transparent to applications so that they do not realize existence of multiple copies of the data warehouse. In effect, even non-technical users can create, populate and update data warehouses with minimal time and effort.

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