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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.
161

Komunikace mezi systémem Android a platformou Arduino / Communication between the Android OS and Arduino Platform

Mychko, Maksim January 2015 (has links)
This thesis deals with creating a library for the Android OS which enables efficient wireless communication with platform Arduino. The target is to create an application for Android OS, using a created library that allows you to capture data from various sensors and control effectors. The work describes basic wireless interfaces for Android OS and Arduino platform. The main benefits and drawbacks functions are also introduced. The comparison of current consumption for modules HM-10 and DIGI S1 has been carried out as well. Possibility of data acquisition and effector controlling exercises have been tested and verified.
162

A Cost-Efficient Bluetooth Low Energy Based Indoor Positioning System for IoT Applications

Vupparige Vijaykumar, Sanjana January 2019 (has links)
The indoor positioning system is a series of networking systems used to monitor/locate objects at indoor area as opposed that of GPS which does the same at outdoor. The increase in the popularity of the Internet of Things made the demand for Bluetooth Low Energy technology more and more essential due to their compatibility in the smartphones which makes it to access easier. The BLE’s reliable signal and accuracy in calculating the distance has a cutting edge on others in IPS. In this thesis, the Bluetooth Low Energy indoor positioning system was designed and implemented in the office area, and the positionofIoTdevicesweremonitored. OntheIoTdevices,thebeaconswereplaced. And thesebeaconswerecoveringtheofficearea. Thereceiver,smartphoneinourcase,recorded theReceivedSignalStrengthIndicationofthetransmittedsignalsfromthebeaconswithin the range of the signal and stored the collected data in a database. Two experiments have beenconducted. Oneisforbeaconsthatarestationaryandonethatismoving. Toevaluate these experiments, a few tests were performed to predict the position of beacons based on therecordedreceivedsignalstrength’s. Inthecaseofstationarybeacons, itoffersaccuracy range from 1 m to 5 m, and 3 m to 9.5 m in anticipating the position of each beacon in the case of moving beacon. This methodology was a mixture of fingerprinting and an algorithm of multilateration. Finally, the experiments show that the algorithm used provides the most accurate indoor position using BLE beacons that can be monitored through an Android-based application in real-time.
163

Production beyond product : Pretoria West bio-diesel plant : Buitekant Street, Pretoria West Industrial area, City of Tshwane

Claassens, Mias 23 March 2011 (has links)
The aim of the dissertation is to investigate the role of Industrial architecture in facilitating emergent functions through adaptive re-use of discarded spaces that will demonstrate low energy architecture, energy production and social integration. The function of the production place in the city is to define production so that it will:<ul><li> Emphasize the community over the individual</li><li> Stimulate production to steer away from the concept of being a linear process that is focused on the product, to that of a cyclical process that imitate the concept of an ecosystem</li><li> Work with existing energy</li><li> Establish emerging opportunities through connectivity between production process and the local urban fabric</li></ul> The industrial intervention of the production place takes the form of a Bio-diesel plant that will be situated on the Pretoria West Power Station, in the Pretoria West Industrial area, west of the City of Tshwane Central Business District. / Dissertation (MArch(Prof))--University of Pretoria, 2010. / Architecture / unrestricted
164

Entwicklung einer Niederenergie-Implantationskammer mit einem neuartigen Bremslinsensystem

Borany, Johannes von, Teichert, Jochen January 2001 (has links)
In diesem Report wird eine Niederenergie-Implantationskammer (NEI-Kammer) beschrieben, die im Forschungszentrum Rossendorf entwickelt und aufgebaut wurde. Die Kammer ermöglicht es, die Implantation von Ionen bei niedrigen Energien (< 30 keV) mit einer Implantationsanlage für mittlere Energien durchzuführen. In der Kammer werden der Ionenstrahl, den der Implanter liefert, auf die erwünschte niedrige Energie abgebremst. Dazu wird ein elektrostatisches Bremslinsensystem eingesetzt, das auf einem neuartigen Prinzip basiert. Das System besteht aus einer Sammellinse und einer Zerstreuungslinse, wobei die Öffnungsfehler beider Linsen entgegengesetzte Vorzeichen besitzen und sich gegenseitig kompensieren. Dadurch ist es möglich, Wafer gebräuchlicher Größe bei geringer Energie mit hoher Dosishomogenität zu implantieren. Die NEI-Kammer ist insbesondere für Forschungseinrichtungen eine vorteilhafte Lösung, da sie eine wesentlich kostengünstigere und flexiblere Alternative zur Anschaffung einer Niederenergie-Implantationsanlage darstellt.
165

Evolution of Ion-Induced Ripple Patterns - Anisotropy, nonlinearity, and scaling

Keller, A. January 2009 (has links)
This thesis addresses the evolution of nanoscale ripple patterns on solid surfaces during low-energy ion sputtering. Particular attention is paid to the long-time regime in which the surface evolution is dominated by nonlinear processes. This is explored in simulation and experiment. In numerical simulations, the influence of anisotropy on the evolution of the surface patterns in the anisotropic stochastic Kuramoto-Sivashinsky (KS) equation with and without damping is studied. For a strong nonlinear anisotropy, a 90 rotation of the initial ripple pattern is observed and explained by anisotropic renormalization properties of the anisotropic KS equation. This explanation is supported by comparison with analytical predictions. In contrast to the isotropic stochastic KS equation, interrupted ripple coarsening is found in the presence of low damping. This coarsening seems to be a nonlinear anisotropy effect that occurs only in a narrow range of the nonlinear anisotropy parameter. Ex-situ atomic force microscopy (AFM) investigations of Si(100) surfaces sputtered with sub-keV Ar ions under oblique ion incidence show the formation of a periodic ripple pattern. This pattern is oriented normal to the direction of the ion beam and has a periodicity well below 100 nm. With increasing ion fluence, the ripple pattern is superposed by larger corrugations that form another quasi-periodic pattern at high fluences. This ripple-like pattern is oriented parallel to the direction of the ion beam and has a periodicity of around one micrometer. Interrupted wavelength coarsening is observed for both patterns. A dynamic scaling analysis of the AFM images shows the appearance of anisotropic scaling at large lateral scales and high fluences. Based on comparison with the predictions of different nonlinear continuum models, the recent hydrodynamic model of ion erosion, a generalization of the anisotropic KS equation, is considered as a potentially powerful continuum description of this experiment. In further in-situ experiments, the dependence of the dynamic scaling behavior of the sputtered Si surface on small variations of the angle of incidence is investigated by grazing incidence small angle X-ray scattering (GISAXS). A transition from strongly anisotropic to isotropic scaling is observed. This indicates the presence of at least two fixed points in the system, an anisotropic and an isotropic one. The dynamic scaling exponents of the isotropic fixed point are in reasonable agreement with those of the Kardar-Parisi-Zhang (KPZ) equation. It remains to be seen whether the hydrodynamic model is able to show such a transition from anisotropic to isotropic KPZ-like scaling.
166

BLE Beacon Based Indoor Positioning System in an Office Building using Machine Learning

Tirumalareddy, Rohan Reddy January 2020 (has links)
Context: Indoor positioning systems have become more widespread over the past decade, mainly due to devices such as Bluetooth Low Energy beacons which are low at cost and work effectively. The context of this thesis is to localize and help people navigate to the office equipment, meeting rooms, etc., in an office environment using machine learning algorithms. This can help the employees to work more effectively and conveniently saving time. Objective: To perform a literature review of various machine learning models in indoor positioning that are suitable for an office environment. Also, to experiment with those selected models and compare the results based on their performance. Android smartphone and BLE beacons have been used to collect RSSI values along with their respective location coordinates for the dataset. Besides, the accuracy of positioning is determined by using state-of-the-art machine learning algorithms to train the dataset. Using performance metrics such as Euclidean distance error, CDF curve of Euclidean distance error, RMSE and MAE to compare results and select the best model for this research. Methods: A Fingerprinting method for indoor positioning is studied and applied for the collection of the RSSI values and (x, y) location coordinates from the fixed beacons. A literature review is performed on various machine learning models appropriate for indoor positioning. The chosen models were experimented and compared based on their performances using performance metrics such as CDF curve, MAE, RSME and Euclidean distance error. Results: The literature study shows that Long Short Term Memory and Multi-layer perceptron, Gradient boosting, XG boosting and Ada boosting is suitable for models for indoor positioning. The experimentation and comparison of these models show that the overall performance of Long short-term memory network was better than multiplayer Perceptron, Gradient boosting, XG boosting and Adaboosting. Conclusions: After analysing the acquired results and taking into account the real-world scenarios to which this thesis is intended, it can be stated that the LSTM network provides the most accurate location estimation using beacons. This system can be monitored in real-time for maintenance and personnel tracking in an office environment.
167

Bearbetning av befintligt bostadsprojekt med syfte att uppnå passivhusstandard / Processing of an existing housing project with a purpose to achieve passive house standard

Stoor Siekkinen, Björn, Hedberg, Carl January 2012 (has links)
I detta examensarbete har energiberäkningar och analyser enligt FEBY12 gjorts på ett radhusområde för att undersöka vad som krävs för att lågenergihusen ska uppnå passivhusstandard. Att uppföra energisnåla byggnader är i dagens samhälle viktigt för alla företag eftersom människor blir allt mer energimedveten och krav från beställare blir allt högre. I arbetet har en modell av radhusområdet modellerats i Revit Architecture för att på ett smidigt sätt få korrekta värden i de olika energiberäkningsprogrammen Vasari, Energihuskalkyl och PHPP. Programmen har helt olika kvalitéer därför har en jämförelse och analys av programmen utförts. Analyser har tydligt visat att det krav som finns för att uppnå passivhusstandard på värmeförlusttalet är betydligt svårare att uppnå än det krav som ställs på den levererade energin. För att uppnå passivhusstandard vidtogs diverse åtgärder såsom U-värde för väggar förbättrades, ventilationsaggregatets verkningsgrad höjdes samt fönsterpartierna reducerades avsevärt. / Energy calculations and analysis have in this thesis paper been made in accordance with the FEBY12 on a row house area to examine what is needed for low energy houses to achieve passive house standards. The ability to construct energy efficient buildings in today’s society is very important for all companies in the business since the people are becoming more and more environmentally conscious and demands from buyers are increasing.  To be able to efficiently obtain accurate values from the different energy calculation programs such as Vasari, Energihuskalkyl and PHPP for this examination, a model was created using Revit Architecture. The programs’ quality strongly differs from each other and therefore analysis and comparisons have been made to reach a result. Analysis clearly shows that the demands to reach passive house standard on rates of heat loss are significantly harder to meet than the demands put on the supplied energy.  To achieve passive house standard several different measures were taken, for example the U-value in the walls were improved, ventilation was made more efficient and the window panels were reduced significantly.
168

Wireless Hybrid Bio-Sensing withMobile based Monitoring System

Xu, Linlin January 2013 (has links)
Personal telehealth plays a crucial role in addressing global challenges of aging population and rising cost for health care. Tiny and wirelessly connected medical sensors, for example embedded in clothes or on the body, will be an integrated part of lifestyle, and will allow hospitals to remotely diagnose patients in their home.  In this thesis, a wireless bio-sensing with smart phone based monitoring system is proposed to provide a home based telehealth care for continuous monitoring. The system consists of two main parts: a wireless sensor and a health application on the smart phone. This thesis is to design the first part of the system - a wireless temperature and electrocardiography (ECG) sensor. The sensor integrates ECG front-end analog block, a micro-controller and a Bluetooth low energy (BLE) connectivity IC on a single board. To achieve the miniaturization of the sensor and users’ comfort in mind, the sensor is designed as a miniaturized hybrid system utilizing flexible batteries and printed electrodes. This can efficiently detect ECG signals and transfer them to a smart phone through BLE link.
169

Indoor positioning utilizing Bluetooth Smart : A comparative study between trilateration and fingerprinting / Inomhuspositionering med Bluetooth Smart

Nygård, Niklas January 2015 (has links)
This thesis explores the possibilities of constructing an indoor positioning system based on Bluetooth Smart technology. Two non-trainable trilateration approaches and two trainable fingerprinting were implemented and evaluated at Mobiento's offices in Stockholm, Sweden. A trilateration approach is based on finding a sought location based on known distances towards know locations, at least three locations and distances are needed. A fingerprinting approach is based on creating a radio map, which describes transmission signals within the room, towards different transmitters. A set amount of coordinates are assigned a fingerprint. These are then used as reference points for a sought location. For each major approach, trilateration and fingerprinting, a weighted approach is conducted. These approaches are evaluated in a disturbance free environment in term of accuracy, implementation and setup. In terms of accuracy, the non-weighted fingerprinting approach performs slightly better than the weighted fingerprinting approaches. Both of these are more accurate than the trilateration approaches. When it comes to implementation and setup, the trilateration algorithms impose less cost. These allow for better scalability when the indoor environment becomes larger.
170

Energy services for high performance buildings and building clusters - towards better energy quality management in the urban built environment

Marmoux, Pierre-Benoît January 2012 (has links)
With an increasing awareness of energy consumption and CO 2emission in the population, several initiatives to reduce CO2emissions have been presented all around the world. The main part of these initiatives is a reduction of the energy consumption for existing buildings, while the others concern the building of eco-districts with low-energy infrastructures and even zero-energy infrastructures. In this idea of reducing the energy consumption and of developing new clean areas, this master thesis will deal with the high energy quality services for new urban districts. In the scope of this master thesis project, the new concept of sustainable cities and of clusters of buildings will be approached in order to clearly understand the future challenges that the world’s population is going to face during this century. Indeed, due to the current alarming environmental crisis, the need to reduce human impacts on the environment is growing more and more and is becoming inescapable. We will present a way to react to the current situation and to counteract it thanks to new clean technologies and to new analysis approaches, like the exergy concept. Through this report, we are going to analyze the concepts of sustainable cities and clusters of buildings as systems, and focus on their energy aspects in order to set indoor climate parameters and energy supply parameters to ensure high energy quality services supplies to high performance buildings. Thanks to the approach of the exergy concept, passive and active systems such as nocturnal ventilation or floor heating and cooling systems have been highlighted in order to realize the ‘energy saving’ opportunities that our close environment offers. This work will be summarized in a methodology that will present a way to optimize the energy use of all services aspects in a building and the environmental friendly characteristics of the energy resources mix, which will supply the buildings’ low energy demands.

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