São inúmeras as atividades que fazem uso do sistema Global Navigation Satellite System - GNSS, sendo o Global Positioning System - GPS, desenvolvido pelos Estados Unidos, o mais utilizado. Na área de agricultura de precisão há a necessidade de posicionamento estático e cinemático com demandas de distintos níveis de acurácia e precisão para diferentes aplicações. A deficiência de informações técnicas dos fabricantes causa incertezas nos usuários, quanto à classe de receptor a ser utilizado para determinadas atividades agrícolas. Por esses motivos os objetivos deste trabalho foram: avaliar o uso de correções diferenciais através de ensaio estático, testar o uso do receptor GPS RTK como referência para avaliar o desempenho de receptores de baixo custo em condição cinemática e desenvolver uma plataforma instrumentada para avaliar os receptores de GPS sob condição cinemática representativa para operações agrícolas. No primeiro caso foram realizados ensaios com oito receptores, sobre uma torre livre de impedimentos físicos, na qual foi montada uma plataforma em formato de cruz e nos receptores foram ativadas e desativadas as correções diferenciais WAAS, EGNOS, SF1 e SF2 e também testadas as várias intensidades de filtragem disponíveis em alguns dos receptores. No ensaio cinemático utilizando um receptor GPS RTK como referência foram utilizados dois receptores de navegação, fixados sobre a cabine de um trator e foram coletados dados com diferentes freqüências. Para ensaios cinemáticos foi construída uma plataforma móvel instrumentada com um detector óptico de pulsos (encoder), um sensor foto elétrico e dois coletores de dados responsáveis por realizar o sincronismo entre os pulsos do encoder e as atualizações da sentença do GPS e armazenamento dos dados. Assim foi possível determinar as coordenadas de referência para o cálculo dos erros de precisão e acurácia do receptor GPS submetido à avaliação. Na avaliação dos receptores em ensaio estático os resultados mostraram que as correções WAAS e EGNOS não adicionam qualidade ao posicionamento na região de Piracicaba, SP. Com a ativação dessas correções os erros de precisão e de acurácia aumentaram. As correções diferencias SF1 e SF2 via satélite demonstraram ser mais acuradas que os demais sistemas ensaiados. O ensaio sob condição cinemática, com GPS RTK de referência, permitiu o cálculo de erros somente no sentido perpendicular ao percurso. A plataforma instrumentada funcionou, cumprindo as expectativas e permitindo o cálculo dos erros de precisão e acurácia, porém demonstrou problemas de robustez nos coletores de dados, necessitando de pequenas melhorias. / The activities that use the Global Navigation Satellite System - GNSS, are countless, and the Global Positioning System - GPS, developed by the United States is the most used today. In precision agriculture there is a need of static and cinematic positioning with demands of distinct levels of accuracy and precision for different applications. Technical information deficiencies from the manufacturers causes uncertainties to the users, as the receiver class to be used for certain agricultural activities. For these reasons the objectives of this work were: evaluate the use of differential corrections through static test, to test the use of RTK GPS as reference to evaluate the performance of low cost receivers under cinematic condition and develop an instrumented platform to evaluate GPS receivers under cinematic condition that represents agricultural operations. In the first case were realized tests with eight receivers, in the top of a tower free of physical obstacles, where it was mounted a platform with cross shape. The differential corrections WAAS, EGNOS, SF1 and SF2 were tested and also some intensities of filtering available in some of the receivers. In one of the cinematic tests, using a RTK GPS as reference, we used two navigation receivers, fixed over a tractor cabin and the data were collected with different frequencies. For the second cinematic test it was built a moving platform instrumented with a pulse optical detector (encoder), a photoelectric sensor and two data loggers, responsible for the synchronization between the encoder pulses and the GPS strings, and also log the data. With that it was possible to determine the reference coordinates to calculate the errors of precision and accuracy of the GPS receiver submitted to evaluation. The evaluation in static way showed that the corrections WAAS and EGNOS do not work in the region of Piracicaba, SP. Activating these corrections the precision and accuracy errors increased. The data collected with the satellite differential corrections SF1 and SF2 got closer to the real coordinate than the other evaluated systems. The test under cinematic condition, with the RTK GPS as reference, allowed the errors calculation only in the perpendicular direction of the course. The instrumented platform worked, accomplishing the expectation and allowing the errors calculation of precision and accuracy, however, showed problems of robustness in the data loggers, needing some improvement.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / A pesquisa foi realizada com o objetivo de avaliar a decomposiÃÃo da folhagem de marmeleiro (Croton sonderianus), em funÃÃo da forma de acondicionamento e disposiÃÃo do material no solo na estaÃÃo seca e na estaÃÃo chuvosa. O experimento foi conduzido na Fazenda Experimental Vale do AcaraÃ, onde foram selecionadas duas Ãreas com 1 ha cada. Uma Ãrea apresentava a vegetaÃÃo preservada e a outra Ãrea sofreu aÃÃes antropogÃnicas. Foram acondicionados 30 g de folhagem de marmeleiro em 72 sacolas de decomposiÃÃo (que foram confeccionadas com malha telada de n 0 com 30 cm x 30 cm) as quais foram divididas em 3 tratamentos: sacolas com ambas as faces livres (A); sacolas com a face superior protegida por um plÃstico transparente (B), sacolas com a face superior protegida por lona branca (C). O delineamento experimental foi inteiramente casualizado em um arranjo fatorial de 3 x 2 x 2 x 2, sendo 3 tipos de sacolas x 2 Ãreas x 2 posiÃÃes x 2 estaÃÃes, com trÃs repetiÃÃes. Foi mensurada a temperatura ambiental, mÃxima e mÃnima, a temperatura do solo, assim como a umidade presente no mesmo, e a radiaÃÃo solar. As taxas de decomposiÃÃo real foram obtidas atravÃs de equaÃÃo, em que houve a subtraÃÃo da porcentagem inicial de biomassa vegetal pela quantidade restante nas sacolas ao fim de cada estaÃÃo. A forma de acondicionamento do material, as posiÃÃes em que os mesmos estavam assim como a influÃncia das estaÃÃes do ano e seus fatores abiÃticos caracterÃsticos, influenciaram na taxa de decomposiÃÃo da folhagem de marmeleiro, sendo que ocorrem maiores taxas de decomposiÃÃo na Ãrea preservada durante o perÃodo chuvoso. / The research was conducted to evaluate the decomposition of leaves of marmeleiro (Croton sonderianus), depending on the shape and arrangement of the packing material in the soil in the dry and rainy seasons. The experiment was conducted at the Fazenda Experimental Vale do AcaraÃ, where two areas were selected with 1 ha each. One area showed the preserved vegetation and other anthropogenic area suffered. Were placed 30 g of leaves of marmeleiro in 72 bags of decomposition (which were made with mesh screened from No. 0 to 30 cm x 30 cm) which were divided into three treatments: bags with both free surfaces (A); bags with the top surface protected by a transparent plastic (B), bags with the top surface protected by white canvas (C). The experimental design was completely randomized in a factorial arrangement of 3 x 2 x 2 x 2, and 3 types of bags x 2 x 2 locations x 2 seasons, with three replications. Was measured at ambient temperature, maximum and minimum soil temperature and the moisture present in it, and solar radiation. Decomposition rates were obtained by real equation, in which there was the subtraction of the initial percentage of plant biomass by the amount remaining in the bags at the end of each season. The form of packaging material, the positions in which they were as well the influence of the seasons and their abiotic characteristics, influence the rate of decomposition of leaves of marmeleiro, with higher rates of degradation occur in the preserved during the rainy season.

Location Based Services (LBS) are a relatively recent multidisciplinary field which brings together many aspects of the fields of hardware design, digital signal processing (DSP), digital image processing (DIP), algorithm design in mathematics, and systematic implementation. LBS provide indirect location information from a variety of sensors and present these in an understandable and intuitive way to users by employing theories of data science and deep learning. Indoor positioning, which is one of the sub-applications of LBS, has become increasingly important with the development of sensor techniques and smart algorithms. The aim of this thesis is to explore the utilisation of indoor positioning algorithms under complex Non-Line of sight (LOS) environments in order to meet the requirements of both commercial and civil indoor localisation services. This thesis presents specific designs and implementations of solutions for indoor positioning systems from signal processing to positioning algorithms. Recently, with the advent of the protocol for the Bluetooth 4.0 technique, which is also called Bluetooth Low Energy (BLE), researchers have increasingly begun to focus on developing received signal strength (RSS) based indoor localisation systems, as BLE based indoor positioning systems boast the advantages of lower cost and easier deployment condition. At the meantime, information providers of indoor positioning systems are not limited by RSS based sensors. Accelerometer and magnetic field sensors may also being applied for providing positioning information by referring to the users' motion and orientation. With regards to this, both indoor localisation accuracy and positioning system stability can be increased by using hybrid positioning information sources in which these sensors are utilised in tandem. Whereas both RSS based sensors, such as BLE sensors, and other positioning information providers are limited by the fact that positioning information cannot be observed or acquired directly, which can be summarised into the Hidden Markov Mode (HMM). This work conducts a basic survey of indoor positioning systems, which include localisation platforms, using different hardware and different positioning algorithms based on these positioning platforms. By comparing the advantages of different hardware platforms and their corresponding algorithms, a Received Signal Strength Indicator (RSSI) based positioning technique using BLE is selected as the main carrier of the proposed positioning systems in this research. The transmission characteristics of BLE signals are then introduced, and the basic theory of indoor transmission modes is detailed. Two filters, the smooth filter and the wavelet filter are utilised to de-noise the RSSI sequence in order to increase localisation accuracy. The theory behind these two filter types is introduced, and a set of experiments are conducted to compare the performance of these filters. The utilisation of two positioning systems is then introduced. A novel, off-set centroid core localisation algorithm is proposed firstly and the second one is a modified Monte Carlo localisation (MCL) algorithm based system. The first positioning algorithm utilises BLE as a positioning information provider and is implemented with a weighted framework for increasing localisation accuracy and system stability. The MCL algorithm is tailor-made in order to locate users' position in an indoor environment using BLE and data received by sensors locating user position in an indoor environment. The key features in these systems are summarised in the following: the capacity of BLE to compute user position and achieve good adaptability in different environmental conditions, and the compatibility of implementing different information sources into these systems is very high. The contributions of this thesis are as follows: Two different filters were tailor-made for de-nosing the RSSI sequence. By applying these two filters, the localisation error caused by small scale fading is reduced significantly. In addition, the implementation for the two proposed are described. By using the proposed centroid core positioning algorithm in combination with a weighted framework, localisation inaccuracy is no greater than 5 metres under most complex indoor environmental conditions. Furthermore, MCL is modified and tailored for use with BLE and other sensor readings in order to compute user positioning in complex indoor environments. By using sensor readings from BLE beacons and other sensors, the stability and accuracy of the MCL based indoor position system is increased further.

Yip, Wai Lee. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 119-124). / Abstracts in English and Chinese. / Abstract --- p.i / 摘要 --- p.ii / Acknowledgement --- p.iii / Table of Content --- p.iv / List of Figure --- p.vi / List of table --- p.viii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Motivation --- p.1 / Chapter 1.2 --- Background information --- p.2 / Chapter 1.2.1 --- Overview of positioning technologies --- p.2 / Chapter 1.2.2 --- Comparison between different positioning systems --- p.7 / Chapter 1.2.3 --- Recent works related to INS --- p.9 / Chapter 1.3 --- Objective --- p.11 / Chapter 1.4 --- Organization of thesis --- p.11 / Chapter Chapter 2 --- Literature Study --- p.13 / Chapter 2.1 --- Introduction to INS --- p.13 / Chapter 2.1.1 --- Coordinate Frames --- p.13 / Chapter 2.1.2 --- Gimbaled INS --- p.16 / Chapter 2.1.3 --- Strapdown INS --- p.17 / Chapter 2.1.4 --- Conventional algorithm of strapdown INS --- p.17 / Chapter 2.2 --- Inertial sensors --- p.19 / Chapter 2.2.1 --- Gyroscope --- p.19 / Chapter 2.2.2 --- Accelerometer --- p.20 / Chapter 2.3 --- Previous works --- p.22 / Chapter 2.4 --- GF-INS --- p.23 / Chapter 2.5 --- Summary --- p.25 / Chapter Chapter 3 --- Performance of MEMS accelerometer in position determination --- p.27 / Chapter 3.1 --- Basic principle --- p.27 / Chapter 3.2 --- Numeric integration --- p.28 / Chapter 3.3 --- Experimental setup --- p.30 / Chapter 3.3.1 --- MEMS Accelerometer --- p.30 / Chapter 3.3.2 --- Microcontroller --- p.32 / Chapter 3.3.3 --- System architecture --- p.33 / Chapter 3.3.4 --- Testing platform --- p.34 / Chapter 3.4 --- Initial calibration and filtering --- p.37 / Chapter 3.4.1 --- Convert ADC reading to acceleration --- p.37 / Chapter 3.4.2 --- Identify configuration error --- p.38 / Chapter 3.4.3 --- Implement low pass filter --- p.39 / Chapter 3.5 --- Experimental results --- p.40 / Chapter 3.5.1 --- Results --- p.40 / Chapter 3.5.2 --- Discussion --- p.43 / Chapter 3.6 --- Summary --- p.45 / Chapter Chapter 4 --- Performance Improvement --- p.46 / Chapter 4.1 --- Fuzzy logic based steady state detector --- p.46 / Chapter 4.1.1 --- Principle --- p.46 / Chapter 4.1.2 --- Experimental result --- p.48 / Chapter 4.2 --- Kalman filtering --- p.50 / Chapter 4.2.1 --- Discrete Kalman filter --- p.50 / Chapter 4.2.2 --- Combine with fuzzy logic based steady state detector --- p.52 / Chapter 4.2.3 --- Experimental results --- p.54 / Chapter 4.3 --- Summary --- p.58 / Chapter Chapter 5 --- Construction of GF-INS --- p.59 / Chapter 5.1 --- Principle of GF-INS --- p.59 / Chapter 5.1.1 --- Algorithm --- p.59 / Chapter 5.1.2 --- Comparing error of GF-INS and conventional INS --- p.66 / Chapter 5.1.3 --- Simulation study --- p.67 / Chapter 5.2 --- Experimental setup --- p.73 / Chapter 5.3 --- Experimental Results --- p.75 / Chapter 5.4 --- Summary --- p.81 / Chapter Chapter 6 --- Improvement on the GF-INS --- p.82 / Chapter 6.1 --- Configuration error compensation --- p.82 / Chapter 6.1.1 --- "Identify bias, scale factor and sensing direction error" --- p.83 / Chapter 6.1.2 --- Identify position error --- p.86 / Chapter 6.1.3 --- Compensator design --- p.89 / Chapter 6.1.4 --- Simulation --- p.91 / Chapter 6.2 --- Fuzzy rule based motion state detector --- p.97 / Chapter 6.2.1 --- Relation of data in different motions --- p.97 / Chapter 6.2.2 --- Fuzzy system --- p.99 / Chapter 6.2.3 --- Membership function training with gradient descent --- p.101 / Chapter 6.3 --- Experimental results and discussion --- p.104 / Chapter 6.3.1 --- Configuration errors --- p.104 / Chapter 6.3.2 --- Compensator --- p.106 / Chapter 6.3.3 --- Fuzzy rule based motion state detector --- p.107 / Chapter 6.3.4 --- Comparing the performance of both methods --- p.110 / Chapter 6.3.5 --- Comparing GF-INS and one dimensional INS --- p.112 / Chapter 6.3.6 --- Discussion --- p.113 / Chapter 6.4 --- Summary --- p.115 / Chapter Chapter 7 --- Conclusions and Future works --- p.116 / Reference --- p.119

Este trabajo pretende aportar en el encuentro de la teoría desde el concepto y elementos de la compra y/o abastecimiento y su relación con el posicionamiento comercial, en función a la Empresa Epade Corporación S.A.C. Ésta es una investigación propositiva This work aims to contribute to the meeting of the theory from the concept and elements of the purchase and / or supply and its relationship with the commercial positioning, according to the company Epade Corporation S.A.C. This is a propositive investigation.

Tese de mestrado integrado. Engenharia Electrotécnica e de Computadores (Automação). Universidade do Porto. Faculdade de Engenharia. 2011

This purpose of this single case study was to describe the discursive practices of an ELL teacher and a general education teaching in a co-teaching PLC setting. With the increased use of co-teaching as an approach to English language development supports, it is vital to gain a better understanding of how teachers plan to support the academic learning of English learners, and what language they use in these interactions. This study implemented a qualitative research design based in grounded theory and positioning theory. The results of this study found that the discursive practices of co-teachers were based in the content of topics, the method of discursive interactions, and their previous experiences in co-teaching that formed their interactions.

Falls are a cause of concern for the elderly since it can render a person immobile. A monitoring system can summon immediate aid by the automatic detection of fall events. The application of ultra-wideband (UWB) signals for a monitoring system was chosen due to its unique characteristics such as wide spectrum, immunity to interference, penetrability, and application for the detection of people. Part of this monitoring system is boundary detection with the purpose of isolating the location of fall events and to function as a mask to define an area of interest. A study of various localizing methods using measurements such as power, distance, and angle with ultra-wideband is presented. A frequency modulated continuous wave (FMCW) based system is an acceptable solution for boundary detection. A FMCW system measures distance with UWB signals. With the addition of a unique reflector, the system is able to identify the reflector via the return frequency-spectrum fingerprint. With distance and the addition angle measurements, the system can determine the boundary with a sensor located at a single location.

The Global Positioning System (GPS) of navigation satellites was first developed for global navigation and position determination purposes. Signals from satellites are delayed by the Earths neutral atmosphere on propagating to ground-based receivers, termed the tropospheric delay. Although an unwanted term for precise positioning, the tropospheric delay may be converted to atmospheric water vapour, which is a vital parameter for weather forecasting.This research investigates the optimum GPS processing strategy to estimate atmospheric water vapour derived from ground-based GPS receivers particularly in the Australian region. For this purpose, GPS data observations from GPS permanent stations across Australia, mainly from the Australian Regional GPS Network, will be processed using scientific GPS software in post-processed mode and near real-time mode.This research shows that by applying high accuracy GPS data processing, the tropospheric delay could be estimated precisely. The quality of GPS data processing is indicated by the station coordinates repeatability since the coordinates can gauge at least a coarse assessment of the ability of the processing method to estimate the tropospheric delay.The precipitable water can be estimated from the wet component after separating the tropospheric delay into dry and wet components. High accuracy GPS data processing is dependent on the best choice of processing strategies, and the correct application of error-correction models and a priori constraints. This research finds that the GPS- PW estimation agrees with Radiosonde-PW estimation with an average of standard deviation at 2.5mm level for post-processed strategy and 2.8mm for near real-time strategy. The standard deviation of tropospheric parameter estimates is 1.1mm for post-processed strategy and 1.5mm for near real-time strategy.

This thesis examines the effect on height determination of the antenna phase centre variation of GPS user segment antennae. A discussion of the various antenna types in common use is followed by an explanation of the problem at hand. In particular the effect of the antenna's environment on the phase centre variation is covered more fully, since the phase variation phenomenon itself is largely unexplained in the engineering community to date. A number of examples of the heighting errors caused by this phenomenon are presented, followed by specifically designed experiments, which quantify the effect. Finally the phase centre variation itself is modelled for a particular GPS antenna in common use by surveyors in Australia. The overall conclusion, arrived at by demonstration, is that the antenna phase centre offsets and the variation model are very important for high accuracy determinations of height.