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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.
11

Interaction with a large sized augmented string instrument intended for a public setting / Interaktion med ett stort augmenterat stränginstrument avsedd för en offentlig miljö

Paloranta, Jimmie January 2016 (has links)
Interactive installations in public settings have increased in popularity over the past decade, as well as the construction of digital musical instruments. In this paper I present a study of the interaction with a large sized augmented string instrument intended for a large installation in a museum, with focus on encouraging creativity, learning, and providing engaging user experiences. In the study, 9 participants were video recorded while playing with the string on their own, followed by an interview focusing on their experiences, creativity, and the functionality of the string. I then used McCarthy and Wright’s framework for analysing technology as experience and Frank E Williams creativity taxonomy model to analyse the results. In line with previous research, results highlight the importance of designing for different levels of engagement (exploration, experimentation, challenge). However, results additionally show that these levels need to consider the users’ age and musical background as these profoundly affect the way the user plays with and experiences the string. / Interaktiva installationer i offentliga miljöer har ökat i popularitet under det senaste decenniet, liksom även skapandet av digitala musikinstrument. I denna uppsats presenterar jag en studie av interaktionen med ett stort augmenterat stränginstrument avsedd för en stor installation i ett museum, med fokus på att uppmuntra kreativitet, lärande, och att ge engagerande användarupplevelser. I studien blev 9 deltagare videoinspelade samtidigt som de spelade med strängen på egen hand, följt av en intervju med fokus på deras upplevelse, kreativitet, och strängens funktionalitet Jag använde sedan McCarthy och Wrights ramverk för att analysera teknik som upplevelse och Frank E Williams kreativitets taxonomi för att analysera resultaten. I linje med tidigare forskning så betonar resultaten vikten av att designa för olika nivåer av engagemang (undersökande, experimenterande, utmaning). Dock så visar resultaten dessutom på att dessa nivåer måste ta hänsyn till användarnas ålder och musikaliska bakgrund då dessa starkt påverkar hur användaren spelar med och upplever strängen.
12

Self-Sensing position determination on a sensor-designed proportional solenoid

Kramer, Thomas, Weber, Jürgen 26 June 2020 (has links)
Proportional valves are widely used in fluid systems for controlling the volume flow rate or fluid pressure. The actuation of this valves is done by PWM-driven proportional solenoids, which enable self-sensing position determination abilities due to air gap-dependent electrical behaviour, e. g. for condition monitoring or position controlling tasks. However, the sensor properties of conventional proportional solenoids are poor due to ambiguities caused by hysteresis effects (magnetic hysteresis, eddy currents) and saturation effects. Thus, a sensor-designed actuator was developed with very low hysteresis effects and unique position determination by using electrical sheet and a particular air gap design. This paper deals with investigations of a novel self-sensing position determination approach on a demonstrator of the sensor-designed solenoid. The advantage of this method is an online consideration of transient effects such as mean current change and armature motion as well as temperature-dependent resistance. For this, a combined evaluation of the differential inductance and flux linkage during PWM periods is proposed.
13

Nondestructive Evaluation of Deteriorated Prestressing Strands Using Magnetic Field Induction

Fernandes, Bertrand 14 June 2010 (has links)
No description available.
14

Etude de l'observabilité de systèmes de Sturm-Liouville : application aux réacteurs biochimiques à paramètres répartis

Delattre, Cédric 22 December 2003 (has links)
Du fait du manque de capteurs fiables et bon marché, la problématique de la reconstruction d'état est cruciale pour les bioprocédés, particulièrement pour les (bio)réacteurs à paramètres répartis. C'est pourquoi il est essentiel d'étudier leurs propriétés d'observabilité, qui peuvent notamment dépendre des dimensions spatiales des capteurs. Dans cette thèse, on étudie tout d'abord l'observabilité d'une classe de réacteurs tubulaires à lit fixe mettant en oeuvre une seule réaction biochimique, où un substrat est dégradé suivant une cinétique non linéaire. Plus précisément, l'analyse porte sur un modèle linéarisé, consistant notamment en une Équation aux Dérivées Partielles (EDP) parabolique linéaire comportant un coefficient non uniforme (c.-à-d. dépendant de la variable spatiale). Ce modèle entre dans le cadre d'une classe particulière de systèmes : les systèmes de Sturm-Liouville. Il s'en déduit que tout nombre fini de modes dominants du système est observable par un capteur (de concentration en substrat) situé en sortie et de largeur suffisamment petite. En outre, considérant un minorant et un majorant du coefficient non uniforme, on détermine une expression numérique, fonction du nombre de modes à observer, qui minore cette largeur. La pertinence de ce résultat est confirmée par un exemple numérique : un biofiltre de dénitrification. Cette étude est étendue à un procédé-pilote de digestion anaérobie de l'INRA-Narbonne. On montre l'existence d'un état d'équilibre, autour duquel le comportement du système est modélisé par deux EDP linéaires, dont une à coefficient non uniforme. La démarche précédente est généralisée et on calcule des expressions des largeurs de deux capteurs en fonction du nombre de modes dont on veut s'assurer qu'ils sont observables. Ce résultat s'applique notamment à la conception d'un estimateur d'état.
15

Gas Sensors - Micro-Heater Designs And Studies On Sensor Film Deposition

Singh, Inderjit 06 1900 (has links)
Current gas sensor technology, although meeting the minimum requirements in many instances, suffers for a number of limitations. Hence, there is currently a considerable volume of research being undertaken at many laboratories of different countries. In the past, all chemical sensors and catalyst were optimized empirically by a trial and error method. Today, however, systematic research and development is becoming increasingly important in order to improve sensors and to find new sensing principles. Obtaining a long term stable gas sensor with improved sensitivity, selectivity, and low cost for mass production passes through fundamental research and material characterization to build new chemically sensitive devices or to improve existing ones. The bottom line in the design and manufacture of modern gas sensors is the transfer from ceramic(of Figaro type) to thin film gas sensors(TFGs). This transfer provides new opportunities for further microminiaturization, power consumption and cost reduction of gas sensors. Therefore, at the present time, thin film gas sensors are the basis for the design of the modern gas sensitive multi-parameter microsensor systems. Applications of these systems include environment, security, home systems, smart buildings, transportation, discrete manufacturing, process industries and so on. Microelectromechanical systems(MEMS) based integrated gas sensors present several advantages for these applications such as ease of array fabrication, small size, and unique thermal manipulation capabilities. MEMS based gas sensors; which are usually produced using a standard CMOS(Complimentary Metal Oxide Semiconductor) process, have the additional advantages of being readily realized by commercial foundries and amenable to the inclusion of on-chip electronics. In order to speed up the design and optimization of such integrated sensors, microheater designs for gas sensor applications have been presented as first part of the present thesis. As heater design is the key part for a gas sensor operation. So 3D simulations have been used to optimize micro-heater geometry. The application of MEMS Design Tool(COVENTORWARE) has been presented to the design and analysis of micro-hotplate (MHP) structures. Coupled Electro-thermal analysis provided an estimation of thermal losses and temperature distribution on the hotplate for realistic geometrical and material parameters pertinent to fabrication technology. Five microheater designs have been proposed in terms of different sizes and shapes in order to optimize the microhotplate structure to be used for gas sensor operation for the specified range of temperature and power consumption. To produce a gas sensor, which is able to detect LPG leak, thin films of tin oxide have been developed. FR sputtering has been used to deposit gas sensitive tin oxide thin filmls under various deposition conditions. Four different values of pressure in the range from high pressure(5 X 10-2 mbar) to lower pressure (2 X 10-3 mbar), three RF power values 50, 75, 100 W and varied oxygen percentage in sputtering atmosphere (0-18%) have been used to optimize the material properties of tin oxide thin films to study the sensitivity towards LPG. All the samples have been analyzed using various macro and microscopic characterization techniques. Extensive studies have been done on the sensor response for the samples deposited under different conditions. Finally the sample film deposited at 5 x 10-3 mbar, with applied power of 75 W in the presence of 8% oxygen, showed maximum sensitivity towards LPG.
16

Design Of Two-Axis Displacement-Amplifying Compliant Mechanisms Using Topology Optimization

Dinesh, M 01 July 2008 (has links)
This thesis deals with the design of two-axis displacement-amplifying compliant mechanisms (DaCMs) using topology optimization. The two-axis compliant mechanisms considered here are XY positioners and two-axis inertial sensors. A building block approach, with several single-axis DaCMs as building blocks, is used to conceive designs of compliant platforms that provide two orthogonal and independent movement of a common platform. Spring-mass-lever (SML) models of these designs are developed to simplify the analysis and design of the complicated arrangements of building blocks. The XY positioners designed in this work have perfectly de-coupled motion without compromising on the frequency; the best design of the stage has a displacement amplification of five resulting in the enhanced range of 4.2 % of the mechanism size–a significant improvement from the 1.67 %, the maximum range of the designs reported so far. Nearly 100% improvement is observed in the sensitivity of the two-axis accelerometer as compared with an existing design that occupied the same area. Multiple prototypes of XY positioners were fabricated on polypropylene sheets using CNC machining; and on spring steel and aluminium using wire-cut electro discharge machining. Mask layouts for two-layer two-axis accelerometers are designed for micro-fabrication using reactive ion etching and wafer bonding.
17

Strukturintegrierbare Sensoren auf Basis piezoelektrischer Polymere / Sensors Based on Piezoelectric Polymers for Structure Integration

Schulze, Robert 07 August 2017 (has links) (PDF)
Die vorliegende Arbeit beschreibt die Entwicklung von Sensoren in einer neuen, großserienfähigen Technologie. Mit dem Mehrkomponentenmikrospritzgießverfahren werden mechanische Sensorstrukturen aus (faserverstärktem) Kunststoff an polymere piezoelektrische Wandler angebunden. Die hergestellten Aufnehmer können über die Weiterverarbeitung mit Hybridtechnologien für die Strukturintegration eingesetzt werden. Diese Dissertation stellt Entwurfsmethoden und Modelle zur Vorausberechnung der neuartigen Sensoren bereit, die zur Qualifizierung der neuen Technologie benötigt werden. Dazu werden bekannte Modellierungsansätze angewandt und wesentliche Erweiterungen für die praktische Nutzung erarbeitet. Entwurfsrelevante technologieabhängige Kenngrößen, wie die elastischen Eigenschaften der verarbeiteten Werkstoffe und die geometrischen Dimensionen der hergestellten Sensorstrukturen werden untersucht und deren Einfluss auf den Entwurfsprozessdargelegt. Die hergestellten Sensoren werden in ihrer Grundfunktion messtechnisch charakterisiert und die System- und Strukturintegration vorgestellt. / The presented work describes the development of sensors in a novel technology approach feasible for large-scale production. By using the multicomponent microinjection molding process, mechanical sensor structures out of (fiber-reinforced) polymers are joined with piezoelectric polymer transducers. The fabricated sensors can be processed further with hybrid manufacturing technologies and adapted for structure integration. This thesis introduces design methods and models for the preliminary calculation of the novel sensors, which are required for a technology qualification. Therefore, existing modelling approaches adapted and essentially extended for practical use. Design relevant parameters related to the technology like the elastic properties of the applied materials or the geometric dimensions of the manufactured sensor structures are characterized and the system and structure integration of the sensors is presented.
18

Application-Specific Things Architectures for IoT-Based Smart Healthcare Solutions

Sundaravadivel, Prabha 05 1900 (has links)
Human body is a complex system organized at different levels such as cells, tissues and organs, which contributes to 11 important organ systems. The functional efficiency of this complex system is evaluated as health. Traditional healthcare is unable to accommodate everyone's need due to the ever-increasing population and medical costs. With advancements in technology and medical research, traditional healthcare applications are shaping into smart healthcare solutions. Smart healthcare helps in continuously monitoring our body parameters, which helps in keeping people health-aware. It provides the ability for remote assistance, which helps in utilizing the available resources to maximum potential. The backbone of smart healthcare solutions is Internet of Things (IoT) which increases the computing capacity of the real-world components by using cloud-based solutions. The basic elements of these IoT based smart healthcare solutions are called "things." Things are simple sensors or actuators, which have the capacity to wirelessly connect with each other and to the internet. The research for this dissertation aims in developing architectures for these things, focusing on IoT-based smart healthcare solutions. The core for this dissertation is to contribute to the research in smart healthcare by identifying applications which can be monitored remotely. For this, application-specific thing architectures were proposed based on monitoring a specific body parameter; monitoring physical health for family and friends; and optimizing the power budget of IoT body sensor network using human body communications. The experimental results show promising scope towards improving the quality of life, through needle-less and cost-effective smart healthcare solutions.
19

In vivo PPy(DBS) sensors to quantify excitability of cells via sodium fluctuations in extracellular solution

Ziebro, Thomas R. 28 June 2017 (has links)
No description available.
20

Strukturintegrierbare Sensoren auf Basis piezoelektrischer Polymere

Schulze, Robert 10 January 2017 (has links)
Die vorliegende Arbeit beschreibt die Entwicklung von Sensoren in einer neuen, großserienfähigen Technologie. Mit dem Mehrkomponentenmikrospritzgießverfahren werden mechanische Sensorstrukturen aus (faserverstärktem) Kunststoff an polymere piezoelektrische Wandler angebunden. Die hergestellten Aufnehmer können über die Weiterverarbeitung mit Hybridtechnologien für die Strukturintegration eingesetzt werden. Diese Dissertation stellt Entwurfsmethoden und Modelle zur Vorausberechnung der neuartigen Sensoren bereit, die zur Qualifizierung der neuen Technologie benötigt werden. Dazu werden bekannte Modellierungsansätze angewandt und wesentliche Erweiterungen für die praktische Nutzung erarbeitet. Entwurfsrelevante technologieabhängige Kenngrößen, wie die elastischen Eigenschaften der verarbeiteten Werkstoffe und die geometrischen Dimensionen der hergestellten Sensorstrukturen werden untersucht und deren Einfluss auf den Entwurfsprozessdargelegt. Die hergestellten Sensoren werden in ihrer Grundfunktion messtechnisch charakterisiert und die System- und Strukturintegration vorgestellt. / The presented work describes the development of sensors in a novel technology approach feasible for large-scale production. By using the multicomponent microinjection molding process, mechanical sensor structures out of (fiber-reinforced) polymers are joined with piezoelectric polymer transducers. The fabricated sensors can be processed further with hybrid manufacturing technologies and adapted for structure integration. This thesis introduces design methods and models for the preliminary calculation of the novel sensors, which are required for a technology qualification. Therefore, existing modelling approaches adapted and essentially extended for practical use. Design relevant parameters related to the technology like the elastic properties of the applied materials or the geometric dimensions of the manufactured sensor structures are characterized and the system and structure integration of the sensors is presented.

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