Dissertations / Theses on the topic 'ADAPTIVE METER'

Worldwide, the number of people living with self-limiting conditions, such as Dementia, Parkinson’s disease and depression, is increasing. The resulting strain on healthcare resources means that providing 24-hour monitoring for patients is a challenge. As this problem escalates, caring for an ageing population will become more demanding over the next decade, and the need for new, innovative and cost effective home monitoring technologies are now urgently required. The research presented in this thesis directly proposes an alternative and cost effective method for supporting independent living that offers enhancements for Early Intervention Practices (EIP). In the UK, a national roll out of smart meters is underway. Energy suppliers will install and configure over 50 million smart meters by 2020. The UK is not alone in this effort. In other countries such as Italy and the USA, large scale deployment of smart meters is in progress. These devices enable detailed around-the-clock monitoring of energy usage. Specifically, each smart meter records accurately the electrical load for a given property at 10 second intervals, 24 hours a day. This granular data captures detailed habits and routines through user interactions with electrical devices. The research presented in this thesis exploits this infrastructure by using a novel approach that addresses the limitations associated with current Ambient Assistive Living technologies. By applying a novel load disaggregation technique and leveraging both machine learning and cloud computing infrastructure, a comprehensive, nonintrusive and personalised solution is achieved. This is accomplished by correlating the detection of individual electrical appliances and correlating them with an individual’s Activities of Daily Living. By utilising a random decision forest, the system is able to detect the use of 5 appliance types from an aggregated load environment with an accuracy of 96%. By presenting the results as vectors to a second classifier both normal and abnormal patient behaviour is detected with an accuracy of 92.64% and a mean squared error rate of 0.0736 using a random decision forest. The approach presented in this thesis is validated through a comprehensive patient trial, which demonstrates that the detection of both normal and abnormal patient behaviour is possible.

In the last 50 years the apertures of the world largest ground-based telescopes doubled, passing from the 5 m of the Hale telescope (1948) to the over 10 m of the Gran Telescopio Canarias, serving the astronomers in their attempts to push further and further the boundaries of our knowledge of the sky. The astronomical community is now looking forward to the era of the 40 m telescope (Extremely Large Telescope, ELT), which will further improve the studies in many astronomical fields, enabling the observation of very faint and distant objects, beyond the limits of the currently known universe. However, since these telescopes are located on the ground and they are naturally affected by atmospherical seeing, even the largest telescope would be equivalent, in term of resolution and image quality, to a telescope of few tens of centimetres in diameter, if the seeing is not compensated. This is exactly the aim of Adaptive Optics, which plays a key role in the modern ground-based telescope, as it allows the telescope to recover, completely or partially, its theoretical resolution imposed by diffraction. Many different kinds and approaches to Adaptive Optics have been proposed in the last decades, each one with its level of correction, sky coverage, complexities etc. LINC-NIRVANA, the Fizeau interferometer for the LBT, is equipped with a complex Multi-Conjugate Adapive Optics system (MCAO), which allows to uniformily correct a 2 arcmin Field of View, enabling interferometric imaging on a 10 x 10 arcsec Field of View with a 23 m telescope equivalent resolution. When operated in this configuration, the LBT can be considered a precursor of the ELTs. In this Thesis I give a detailed description of the MCAO system serving LINC-NIRVANA, and in particular of its main subsystems, the Ground layer Wavefront Sensor (GWS) and the High layer Wavefront Sensor (HWS). I give an overview of the optical concepts and layout of the MCAO module, going through the definition of the alignment procedures defined to match the tight tolerances required to correctly operate the instrument, and concluding with the results and verifications of the alignment. I also widely describe the operations and the results of a Pathfinder Experiment, in which one of the two GWSs has been tested at the LBT as a stand alone system in order to verify its ability to drive the Adaptive Secondary Mirror of the LBT and also our ability to make it possible. In this way we acquired experience in view of the LINC-NIRVANA commissioning, planned at the end of 2016. Since LINC-NIRVANA is an Italian/German collaboration, the work described in this Thesis was carried out in three countries: Italy, Germany and U.S.
Negli ultimi 50 anni il diametro dei principali telescopi a terra del mondo è più che raddoppiato, passando dai circa 5 m del telescopio Hale ai più di 10 m del telescopio Gran Telescopio Canarias, in risposta alle necessità del mondo astronomico nel suo tentativo di spingere sempre più lontano i confini della nostra conoscenza della volta celeste. La comunità astronomica è ora proiettata ed in attesa dell’era dei telescopi da 40 m, che permetteranno di migliorare le nostre conoscenze e la nostra comprensione in moltissimi campi astronomici, permettendo di osservare sorgenti sempre più deboli e lontane, spingendo il nostro sguardo oltre i limiti attuali, fino ai sfiorare i confini dell’Universo appena nato. Tuttavia, dal momento che i telescopi a terra sono affetti dal fenomeno naturale del seeing, dovuto alla presenza di un mezzo turbolento tra il telescopio e la volta celeste (l’atmosfera), anche il telescopio più grande diverrebbe equivalente, quantomeno in termini di risoluzione e qualità dell’immagine, a un telescopio di poche decine di centimetri se non si risolve il problema del seeing. Questo è esattamente il proposito dell’Ottica Adattiva, che gioca un ruolo chiave nelle osservazioni astronomiche da terra, dal momento che permette ai telescopi di riacquisire, totalmente o in parte a seconda della tecnica di Ottica Adattiva utilizzata, il loro limite di risoluzione teorico imposto dalla diffrazione. Data la sua importanza, negli ultimi decenni sono stati sviluppati molti sistemi e concetti di Ottica Adattiva, ognuno con le sue peculiarità e caratteristiche. LINC-NIRVANA, l’interferometro di Fizeau per il Large Binocular Telescope, è equipaggiato con un complesso modulo di Ottica Adattiva Multiconiugata (MCAO), che consente di correggere uniformemente un campo di vista di 2 arcmin, permettendo di ottenere immagini interferometriche su un campo di 10 x 10 arcsec, molto esteso se comparato ad altri interferometri, con una risoluzione equivalente a quella di un telescopio di 23 m. In sostanza, in questa configurazione, LBT può essere considerato un precursore degli ELTs. In questo Tesi darò una descrizione dettagliata del modulo MCAO equipaggiato a LINC-NIRVANA, concentrandomi in particolare sui due principali sottosistemi che lo costituiscono: il Ground layer Wavefront Sensor (GWS) e l’High layer Wavefront Sensor (HWS). Darò una panoramica dei concetti di ottica su cui si basano questi sensori, definirò le procedure di allineamento utilizzate per soddisfare le rigide tolleranze imposte per poter operare lo strumento con buone prestazioni e infine descriverò i risultati dell’allineamento e di verifica. Inoltre, descriverò le attività e i risultati ottenuti durante un Pathfinder Experiment, il cui scopo principale è stato sia verificare le prestazioni di uno dei due GWSs come un sistema a sé stante, comandando lo specchio secondario adattivo di LBT, sia le nostre capacità di renderlo possibile, acquisendo esperienza per il futuro commissioning di LINC-NIRVANA, previsto per la fine del 2016. Essendo LINC-NIRVANA una collaborazione Italia/Germania, le attività effettuate dallo scrivente e descritte in questa Tesi sono state svolte in Italia, Germania e USA (per il Pathfinder).

Дисертаційна робота присвячена вирішенню актуальної науково-практичної проблеми в телекомунікаційних системах, а саме підвищення пропускної здатності каналу передачі семантичних мовних даних за рахунок ефективного їх кодування, тобто формулюється питання підвищення ефективності семантичного кодування, а саме – з якою мінімальною швидкістю можливо кодувати семантичні ознаки мовних сигналів із заданою ймовірністю безпомилкового їх розпізнавання? Саме на це питання буде дана відповідь у даному науковому дослідженні, що є актуальною науково-технічною задачею враховуючи зростаючу тенденцію дистанційної взаємодії людей і роботизованої техніки за допомогою мови, де безпомилковість функціонування даного типу систем безпосередньо залежить від ефективності семантичного кодування мовних сигналів. У роботі досліджено відомий метод підвищення ефективності семантичного кодування мовних сигналів на основі мел-частотних кепстральних коефіцієнтів, який полягає в знаходженні середніх значень коефіцієнтів дискретного косинусного перетворення прологарифмованої енергії спектра дискретного перетворення Фур'є обробленого трикутним фільтром в мел-шкалі. Проблема полягає в тому, що представлений метод семантичного кодування мовних сигналів на основі мел-частотних кепстральних коефіцієнтів не дотримується умови адаптивності, тому було сформульовано основну наукову гіпотезу дослідження, яка полягає в тому що підвищити ефективність семантичного кодування мовних сигналів можливо за рахунок використання адаптивного емпіричного вейвлет-перетворення з подальшим застосуванням спектрального аналізу Гільберта. Під ефективністю кодування розуміється зниження швидкості передачі інформації із заданою ймовірністю безпомилкового розпізнавання семантичних ознак мовних сигналів, що дозволить значно знизити необхідну смугу пропускання, тим самим підвищуючи пропускну здатність каналу зв'язку. У процесі доведення сформульованої наукової гіпотези дослідження були отримані наступні результати: 1) вперше розроблено метод семантичного кодування мовних сигналів на основі емпіричного вейвлетперетворення, який відрізняється від існуючих методів побудовою множини адаптивних смугових вейвлет-фільтрів Мейера з подальшим застосуванням спектрального аналізу Гільберта для знаходження миттєвих амплітуд і частот функцій внутрішніх емпіричних мод, що дозволить визначити семантичні ознаки мовних сигналів та підвищити ефективність їх кодування; 2) вперше запропоновано використовувати метод адаптивного емпіричного вейвлет-перетворення в задачах кратномасштабного аналізу та семантичного кодування мовних сигналів, що дозволить підвищити ефективність спектрального аналізу за рахунок розкладання високочастотного мовного коливання на його низькочастотні складові, а саме внутрішні емпіричні моди; 3) отримав подальший розвиток метод семантичного кодування мовних сигналів на основі мел-частотних кепстральних коефіцієнтів, але з використанням базових принципів адаптивного спектрального аналізу за допомогою емпіричного вейвлет-перетворення, що підвищує ефективність даного методу.
The thesis is devoted to the solution of the actual scientific and practical problem in telecommunication systems, namely increasing the bandwidth of the semantic speech data transmission channel due to their efficient coding, that is the question of increasing the efficiency of semantic coding is formulated, namely – at what minimum speed it is possible to encode semantic features of speech signals with the set probability of their error-free recognition? It is on this question will be answered in this research, which is an urgent scientific and technical task given the growing trend of remote human interaction and robotic technology through speech, where the accurateness of this type of system directly depends on the effectiveness of semantic coding of speech signals. In the thesis the well-known method of increasing the efficiency of semantic coding of speech signals based on mel-frequency cepstral coefficients is investigated, which consists in finding the average values of the coefficients of the discrete cosine transformation of the prologarithmic energy of the spectrum of the discrete Fourier transform treated by a triangular filter in the mel-scale. The problem is that the presented method of semantic coding of speech signals based on mel-frequency cepstral coefficients does not meet the condition of adaptability, therefore the main scientific hypothesis of the study was formulated, which is that to increase the efficiency of semantic coding of speech signals is possible through the use of adaptive empirical wavelet transform followed by the use of Hilbert spectral analysis. Coding efficiency means a decrease in the rate of information transmission with a given probability of error-free recognition of semantic features of speech signals, which will significantly reduce the required passband, thereby increasing the bandwidth of the communication channel. In the process of proving the formulated scientific hypothesis of the study, the following results were obtained: 1) the first time the method of semantic coding of speech signals based on empirical wavelet transform is developed, which differs from existing methods by constructing a sets of adaptive bandpass wavelet-filters Meyer followed by the use of Hilbert spectral analysis for finding instantaneous amplitudes and frequencies of the functions of internal empirical modes, which will determine the semantic features of speech signals and increase the efficiency of their coding; 2) the first time it is proposed to use the method of adaptive empirical wavelet transform in problems of multiscale analysis and semantic coding of speech signals, which will increase the efficiency of spectral analysis due to the decomposition of high-frequency speech oscillations into its low-frequency components, namely internal empirical modes; 3) received further development the method of semantic coding of speech signals based on mel-frequency cepstral coefficients, but using the basic principles of adaptive spectral analysis with the application empirical wavelet transform, which increases the efficiency of this method. Conducted experimental research in the software environment MATLAB R2020b showed, that the developed method of semantic coding of speech signals based on empirical wavelet transform allows you to reduce the encoding speed from 320 to 192 bit/s and the required passband from 40 to 24 Hz with a probability of error-free recognition of about 0.96 (96%) and a signal-to-noise ratio of 48 dB, according to which its efficiency increases 1.6 times in contrast to the existing method. The results obtained in the thesis can be used to build systems for remote interaction of people and robotic equipment using speech technologies, such as speech recognition and synthesis, voice control of technical objects, low-speed encoding of speech information, voice translation from foreign languages, etc.

The Wireless Sensor Network consists of a large number of limited battery powered sensor nodes. These networks have wide range of applications related to areas like weather monitoring, forest monitoring, security and target monitoring, etc. The limited powered battery affects the network‟s lifetime. Various protocols have been developed to increase the network‟s lifetime. In this dissertation, we developed EECHR protocol, a clustering protocol for reactive network with threshold sensitive homogeneous sensor nodes. It includes an energy efficient cluster head selection and cluster formation techniques. It also includes an adaptive feature to make the BS aware of the status of nodes in the network which remains idle for long time. It also provides preference to the nodes sensing critical information to directly send their information to the BS. The nodes sensing critical information are released from the burden of becoming CH and they don‟t take part in CH selection. Our proposed protocol performs better than the other conventional protocol like LEACH, E-LEACH, I-LEACH. We also develop a multi hop routing protocol ATEEM for the homogeneous reactive network. It provides an energy efficient data transfer mechanism which is used by the critical nodes to transfer data to BS, by CHs to transmit data to BS and also by Non- CH node to transmit data to CH node. It includes an energy efficient cluster formation mechanism. We have also developed a mechanism to find the critical region in the given network area on the basis of information stored in the BS. It performed better than the EECHR protocol and TEEN protocol.

Smart radial distribution grids will include advanced metering infrastructure (AMI) and significant distributed generators (DGs) connected close to loads. DGs in these radial distribution systems (RDS) introduce bidirectional power flows (BPFs) and contribute to fault current. These BPFs may cause unwanted tripping of existing overcurrent (OC) protection devices and result in permanent outages for a large number of customers. This thesis presents a protection approach that modified an existing overcurrent protection scheme to reduce the number of customers affected by faults in RDS with DGs. Further, a technique is presented that utilizes customers loading information from smart meters in AMI to improve the sensitivity of substation OC relays by adaptively changing the pickup settings. The modified protection approach involves predefining zones in RDS with DGs and installing directional OC relays and circuit breakers at the zonal boundaries. Zonal boundary relays determine faulted zones by sharing information on the direction of detected faults current using binary state signals over a communication medium. The technique to adapt the substation relay pickup settings uses the demand measurements from smart meters for two 12-hour intervals from the previous day to determine the maximum diversified demand at the relay?s location. The pickup settings of the substation relay for the two 12-hour intervals during the following day for the zone supplied by the substation are adaptively set based on the current that corresponds to the maximum diversified demand from the previous day. The techniques were validated through simulations in EMTP/PSCAD using an expanded IEEE 34 node radial test feeder that included DGs and a secondary distribution level. By decentralizing the control of the zonal boundary breakers, the single point of failure was eliminated in the modified protection approach. The cases studied showed that the modified protection approach allows for selective identification and isolation of the faulted zones. Also, the sensitivity of the substation OC relay was improved by at least 24% by using the pickup settings for the two 12-hour intervals from the smart meter demand measurements compared to the pickup settings computed using the conventional methodology based on the maximum loading of the zone.

Some nonlinear and adaptive digital image filtering algorithms have been developed in this thesis to suppress additive white Gaussian noise (AWGN), bipolar fixed-valued impulse, also called salt and pepper noise (SPN), random-valued impulse noise (RVIN) and their combinations quite effectively. The present state-of-art technology offers high quality sensors, cameras, electronic circuitry: application specific integrated circuits (ASIC), system on chip (SOC), etc., and high quality communication channels. Therefore, the noise level in images has been reduced drastically. In literature, many efficient nonlinear image filters are found that perform well under high noise conditions. But their performance is not so good under low noise conditions as compared to the extremely high computational complexity involved therein. Thus, it is felt that there is sufficient scope to investigate and develop quite efficient but simple algorithms to suppress low-power noise in an image. When...

Modem technology has revived interest in the once popular area of meteor scatter communications. Meteor scatter systems offer reliable communications in the 500 to 2000 km range all day, every day. Recent advances in microprocessor technology have made meteor scatter communications a viable and cost effective method of providing modest data rate communications. A return to the basic fundamentals has revealed characteristics of meteor scatter propagation that can be used to optimize the protocols for a meteor scatter link. The duration of an underdense trail is bounded when its initial amplitude is known. The upper bound of the duration is determined by maximizing the classical underdense model. The lower bound is determined by considering the volume of sky utilized. The duration distribution between these bounds is computed and compared to measured values. The duration distribution is then used to specify a fixed data rate, frame adaptive protocol which more efficaciously utilizes underdense trails, in the half duplex environment, than a non-adaptive protocol. The performance of these protocols is verified by modeling.
Thesis (Ph.D.)-University of Natal, Durban, 1987.