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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

A Deep Learning and Auto-Calibration Approach for Food Recognition and Calorie Estimation in Mobile e-Health

Kuhad, Pallavi January 2015 (has links)
High calorie intake has proved harmful worldwide, as it has led to many diseases. However, dieticians have deemed that a standard intake of number of calories is essential to maintain the right balance of calorie content in human body. In this thesis, we consider the category of tools that use image processing to recognize single and multiple mixed-food objects, namely Deep Learning and the Support Vector Machine (SVM). We propose a method for the fully automatic and user-friendly calibration of the sizes of food portions. This calibration is required to estimate the total number of calories in food portions. In this work, to compute the number of calories in the food object, we go beyond the finger-based calorie calibration method that has been used in the past, by automatically measuring the distance between the user and the food object. We implement a block resize method that uses the measured distance values along with the recognized food object name to further estimate calories. While measuring distance, the system also assists the user in real time to capture an image that enables the quick and accurate calculation of the number of calories in the food object. The experimental results showed that our method, which uses deep learning to analyze food objects, led to an improvement of 16.58% in terms of recognition, over the SVM-based method. Moreover, the block resize method showed that percentage error for calorie estimation was reduced to 3.64% as compared to 5% achieved in previous methods.
12

Fotogrammetrická analýza obrazů / Photogrammetric Image Analysis

Velebová, Jana January 2011 (has links)
This thesis is dedicated photogrammetric image analysis that makes it possible from your photos with the help selected methods to determine the location and dimensions of objects recorded on them. There are explained the basics of photogrammetry and its current application. Chapters focused on digital imaging describing its characteristics, treatment options and key points findability for the scene calibration. For a comprehensive view are in this thesis introduced examples of existing software, its possibilities and use in practice.
13

Optimalizace odhadu vzdálenosti v bezdrátové ad-hoc síti / Distance Estimation in Wireless Ad-hoc Network

Botta, Miroslav January 2011 (has links)
The work deals with processing of radio received signal strength in IEEE 802.15.4 which communicates in 2.4 GHz ISM band. The signal is processed by the three approximation methods. They are tested for their effectiveness for measuring in different radio environments. Furthermore, the work deals with calculation of the most efficient coefficients for distance calculating by radio transmission fucntions. It defines the issues of such solutions on practical examples. The work also deals with the experimental algorithm for implementing dynamic calibration of the coefficients. It describes the design, processing and verification of this system in practice.
14

Epochenvergleiche von Präzisions-EDM-Messungen zur Untersuchung der Punktstabilität auf einer EDM-Basislinie

Lehmann, Rüdiger, Attrodt, Antje January 2016 (has links)
Auf der von der Hochschule für Technik und Wirtschaft Dresden betriebene EDM-Basislinie im Großen Garten in Dresden werden regelmäßig die Sollstrecken überprüft. Die Ergebnisse deuten auf Punktbewegungen hin. Durch Vergleiche zweier Epochen wird versucht, solche Punktbewegungen statistisch nachzuweisen, sowohl mittels statistischer Hypothesentests, als auch mit einem Informationskriterium. Punktbewegungen von bis zu 0,25 mm/a wurden geschätzt. Über die Ursachen wird noch spekuliert.
15

Vision for the Blind

Atighechi, Arsham, Haidari, Hussein January 2018 (has links)
How can we improve the living standards of the visuallyimpaired using an Arduino?Living with visual impairment could potentially be oneof the hardest things one could do. Constantly having toworry about obstacles and carrying a stick to feel your wayforward. In order to combat this difficulty, we have designedVision for the Blind.One of the usages of ultrasonic sensors are to measurethe distance from objects using sound waves. These sensors,in combination with Piezo buzzers, have been used inVision for the Blind to warn the user of incoming obstaclesby emitting sound from the buzzers. The volume of thebuzzers is controlled by using a digital potentiometer andvaries depending on the measured distance. All three areconnected to an Arduino which has been coded to performthe given task. / Hur kan vi öka levnadsstandarden för visuellt nedsattamänniskor med hjälp av en Arduino?Att leva med visuell nedsättning är självklart ett stortproblem som medför svårigheter, att alltid vara orolig överhinder som kan finnas i vägen eller bära en pinne med sigför att hitta sin väg. För att bekämpa de här svårigheternahar vi konstruerat Vision for the Blind.Ultraljudsbaserade sensorer använder ljudvågor för attmäta avstånd från ett objekt. Dessa sensorer har använtsi Vision for the Blind i kombination med Piezo sumrarför att varna användaren om inkommande hinder genomatt emittera ljud från sumrarna. Ljudvolymen kontrollerasmed hjälp av en digital potentiometer och varierar med detuppmätta avståndet. Alla tre är kopplade till en Arduinosom är kodad för att utföra det givna uppdraget.
16

EDGE-SUPPRESSED COLOR IMAGE INDEXING AND RETRIEVAL USING ANGLE-DISTANCE MEASUREMENT IN THE SCALED-SPACE OF PRINCIPAL COMPONENTS

Bobik, Sergei January 2000 (has links)
No description available.
17

Aircraft Distance Measurement System

Filho, Nelson Whitaker 10 1900 (has links)
International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / The Aircraft Distance Measurement System (ADMS) could be used in Flight Test application to determine the aircraft position and speed during takeoff, landing and acceleration-stop performance test within runway limits using a microwave link.
18

Distance Measurement Error Modeling for Time-of-Arrival Based Indoor Geolocation

Alavi, Bardia 03 May 2006 (has links)
In spite of major research initiatives by DARPA and other research organizations, precise indoor geolocation still remains as a challenge facing the research community. The core of this challenge is to understand the cause of large ranging errors in estimating the time of arrival (TOA) of the direct path between the transmitter and the receiver. Results of wideband measurement in variety of indoor areas reveal that large ranging errors are caused by severe multipath conditions and frequent occurrence of undetected direct path (UDP) situations. Empirical models for the behavior of the ranging error, which we refer to as the distance measurement error (DME), its relation to the distance between the transmitter and the receiver and the bandwidth of the system is needed for development of localization algorithms for precise indoor geolocation. The main objective of this dissertation is to design a direct empirical model for the behavior of the DME. In order to achieve this objective we provide a framework for modeling of DME, which relates the error to the distance between the transmitter and the receiver and bandwidth of the system. Using this framework we first designed a set of preliminary models for the behavior of the DME based on the CWINS proprietary measurement calibrated ray-tracing simulation tool. Then, we collected a database of 2934 UWB channel impulse response measurements at 3-8GHz in four different buildings to incorporate a variety of building materials and architectures. This database was used for the design of more in depth and realistic models for the behavior of the DME. The DME is divided into two components, Multipath-DME (MDME) and UDP-DME (UDME). Based on the empirical data, models for the behavior of each of these components are developed. These models reflect the sensitivity to bandwidth and show that by increasing the bandwidth MDME decreases. However in UDME the behavior is complicated. At first it reduces as we increase the bandwidth but after a certain bandwidth it starts to increase. In addition to these models through an analysis on direct path power versus the total power the average probability of having a UDP was calculated.
19

ColoroPhone : Design and implementaion of a distance measurement system for object detection

Ward, Jon Åge January 2018 (has links)
In this project, I have developed and built a new prototype of the ColoroPhone visual aid. This new prototype has sensors to measure the distance to objects in front of the wearer, which then communicates with a mobile application that generates sounds depending on the distance to the object. The user will hear this sound through bone-conducting headphones This addition to the ColoroPhone is intended to further enhance the assistance the device can offer. The current prototype is a functioning version and will be used in further research done by a group of psychologists, which will study how such devices affect users both on a biological and social level. They will also evaluate how to approach user training. The prototype in its current state have several segments that have considerable room for improvement in further development of the platform. Some of these improvements can be in form of better Bluetooth implementation, better or more sensors, or improvements in the current set of sensors regarding noise handling and data processing. This type of device can have large impact on the daily life for a large and growing amount of people across the world, as independence is a large factor in a persons feel of self-worth and long term psychological health.
20

CMOS time-to-digital converter structures for the integrated receiver of a pulsed time-of-flight laser rangefinder

Nissinen, I. (Ilkka) 25 October 2011 (has links)
Abstract The aim of this thesis was to develop time-to-digital converters (TDC) for the integrated receiver of a pulsed time-of-flight (TOF) laser rangefinder aiming at cm-level accuracy over an input range of 10 m – 15 m. A simple structure, a high integration level and low power consumption are the desired features for such a TDC. From the pulsed TOF laser rangefinder point of view an integrated receiver consisting of both the TDC and the receiver channel on the same die offers the possibility of manufacturing these laser rangefinders with a high integration level and at a low price to fulfil the needs of mass industrial markets. The heart of the TDC is a CMOS ring oscillator, the clock frequency of which is used to calculate the full clock cycles between timing signals, the positions of the timing signals inside the clock period being determined by storing the state of the phase of the ring oscillator for each timing signal. This will improve the resolution of the TDC. Also, additional delay lines are used to generate multiple timing signals, each having a time difference of a fraction of that of the ring oscillator. This will further improve the resolution of the whole TDC. To achieve stable results regardless of temperature and supply voltage variations, the TDC is locked to an on-chip reference voltage, or the resolution of the TDC is calibrated before the actual time interval measurement. The systematic walk error in the receiver channel caused by amplitude variation in the received pulse is compensated for by the TDC measuring the slew rate of the received pulse. This time domain compensation method is not affected by the low supply voltage range of modern CMOS technologies. Three TDC prototypes were tested. A single-shot precision standard deviation of 16 ps (2.4 mm) and a power consumption of 5.3 mW/channel were achieved at best over an input range of 100 ns (15 m). The temperature drifts of an on-chip voltage reference-locked TDC and a TDC based on the calibration method were 90 ppm/°C and 0.27 ps/°C, respectively. The results also showed that a pulsed TOF laser rangefinder with cm-level accuracy over a 0 – 15 m input range can be realized using the integrated receiver with the time domain walk error compensation described here. / Tiivistelmä Väitöskirjatyön tavoitteena oli kehittää aika-digitaalimuunninrakenteita valopulssin kulkuajan mittaukseen perustuvan lasertutkan integroituun vastaanottimeen. Tavoitteena oli saavuttaa senttimetriluokan tarkkuus 10 m – 15 m mittausalueella koko lasertutkan osalta. Aika-digitaalimuuntimelta vaaditaan yksinkertaista rakennetta, korkeaa integroimisastetta ja matalaa tehonkulutusta. Integroitu vastaanotin sisältää sekä aika-digitaalimuuntimen että vastaanotinkanavan ja tarjoaa mahdollisuuden korkeasti integroidun lasertutkan valmistukseen halvalla teollisuuden massamarkkinoiden tarpeisiin. Aika-digitaalimuuntimen ytimenä toimii monivaiheinen CMOS-rengasoskillaattori. Aika-digitaalimuunnos perustuu rengasoskillaattorin täysien kellojaksojen laskentaan laskurilla ajoitussignaalien välillä. Lisäksi rengasoskillaatorin jokaisesta vaiheesta otetaan näyte ajoitussignaaleilla niiden paikkojen määrittämiseksi kellojakson sisällä, jolloin aika-digitaalimuuntimen erottelutarkkuutta saadaan parannettua. Erottelutarkkuutta parannetaan lisää viivästämällä ajoitussignaaleja viive-elementeillä ja muodostamalla näin useita erillisiä ajoitussignaaleja, joiden väliset viive-erot ovat murto-osa rengasoskillaattorin viive-elementin viiveestä. Aika-digitaalimuunnin stabiloidaan käyttöjännite- ja lämpötilavaihteluja vastaan lukitsemalla se integroidun piirin sisäiseen jännitereferenssiin, tai sen erottelutarkkuus määritetään ennen varsinaista aikavälinmittausta erillisellä kalibrointimittauksella. Vastaanotetun valopulssin amplitudivaihtelun aiheuttama systemaattinen ajoitusvirhe integroidussa vastaanotinkanavassa kompensoidaan mittaamalla vastaanotetun valopulssin nousunopeus aika-digitaalimuuntimella. Tällainen aikatasoon perustuva kompensointimetodi on myös suorituskykyinen nykyisissä matalakäyttöjännitteisissä CMOS-teknologioissa. Työssä valmistettiin ja testattiin kolme aika-digitaalimuunninprototyyppiä. Muuntimien kertamittaustarkkuuden keskihajonta oli parhaimmillaan 16 ps (2,4 mm) ja tehonkulutus alle 5,3 mW/kanava mittausetäisyyden olessa alle 100 ns (15 m). Sisäiseen jännitereferenssiin lukitun aika-digitaalimuuntimen lämpötilariippuvuudeksi mitattiin 90 ppm/°C ja kalibrointimenetelmällä saavutettiin 0,27 ps/°C lämpötilariipuvuus. Työssä saavutetut tulokset osoittavat lisäksi, että valopulssin kulkuajan mittaukseen perustuvalla lasertutkalla on saavutettavissa senttimetriluokan tarkkuus 0 – 15 m mittausalueella käyttämällä tässä työssä esitettyä integroitua vastaanotinta ja aikatason ajoitusvirhekompensointia.

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