Dissertations / Theses on the topic 'Frequency meter'

Dažnio matavimo stendo sudarymas ir tyrimas. Magistro baigiamasis darbas elektronikos inžinerijos laipsniui. Vilniaus Gedimino technikos universitetas. Vilnius, 2014, 71 p., 31 iliustr., 3 lent., 36 bibl., 6 priedai. Sukurtas ir ištirtas dažnio matavimo stendas, atskleidžiantis skaitmeninių dažnio ir periodo matavimo būdų ypatumus. Stendas pakeis šiuo metu laboratoriniuose darbuose naudojamus pasenusius prietaisus. Stendą sudaro 3 užduodantys generatoriai, dažnio sintezatorius, dažniamatis ir sąsaja su asmeniniu kompiuteriu, bendrame korpuse. Matavimo rezultatams įvertinti sukurta specializuota programinė įranga. Atlikus stendo tyrimus įsitikinta, kad sukurtas dažniamačio stendas atitinka visus užduoties reikalavimus.
Creation and investigation of frequency counter. Master's thesis in electronics engineering degree. Vilnius Gediminas Technical University. Vilnius , 2014, 71 p., 31 pictures, 3 tables, 36 references, 6 extras. Frequency counter stand have been created and investigated. Stand will allow students to familiarize themselves with particularities of digital measurement methods of frequency and duration of the period. The new stand will replace old measurement devices that are used during laboratory works recently. The stand consists of frequency synthesizer, frequency counter, 3 different reference generators and interface to the computer packed in single case. Specialized software have been created to assess and treat measurements results. Testing results of the bench proved that created frequency counter stand meets all the requirements of the task.

Темою кваліфікаційної роботи є розробка конcтрукції цифрового частотоміра, розраховано його основні технічні параметри, проведено якісну та кількісну оцінку технологічності, визначено умови аксплуатації та показники собівартості розкрито призначення, область застосування та технічні вимоги до проектованого радіопристрою, здійснено вибір елементної бази, описано принцип роботи по електричній принциповій схемі, та виконано її аналіз, виконано розрахунок електричних параметрів окремих каскадів та обґрунтування виробу і опис конструкції, розраховано надійність пристрою, здійснено аналіз технологічності конструкції виробу і розроблено маршрутно-операційної технології складання і монтажу друкованого вузла.
The topic of qualification work is the development of the Development of a digital frequency meter, its main technical parameters are calculated, qualitative and quantitative assessment of manufacturability is carried out, operating conditions and cost indicators are determined, purpose, scope and technical requirements to the designed radio device are revealed. according to the electrical schematic diagram, and its analysis is performed, calculation of electrical parameters of individual stages and substantiation of the product and design description, calculated reliability of the device, analysis of manufacturability of the product design and developed route-operational technology of assembly and installation of the printed assembly.
ВCТУП...6 1 ЗАГАЛЬНОТЕХНІЧНА ЧАСТИНА ЧАСТИНА ...8 1.1 Призначення і область застосування виробу...8 1.2 Вибір та пояснення структурної схеми...9 1.3 Пояснення принципу роботи та аналіз електричних схем...10 2 КОНСТРУКТОРСЬКО-ТЕХНОЛОГІЧНА ЧАСТИНА...12 2.1 Опис макета виробу. Причини вибору матеріалів та покриттів... 12 2.2 Обґрунтування вибору конструкції...12 2.3 Вибір елементної бази...13 2.4 Розрахунок електричних параметрів окремих каскадів...27 2.5 Оцінка теплового режиму роботи виробу, обчислення площі радіатора...33 2.6 Розрахунок надійності проектованого виробу ...33 2.7 Розрахунок споживаної потужності ...35 2.8 Загальна інформація про збірку та монтаж розробленого виробу. Вибирання типу технології ...36 2.9 Оцінка технологічності виробництва виробу. Підбір інструментів, приладів та обладнання ...37 2.10 Опис технології виготовлення друкованої плати. Вибір основних та допоміжних матеріалів...42 2.11 Кількісна оцінка технологічності друкованого вузла ...44 2.12 Розробка та проектування експлуатаційної технології маршруту та монтажу виробу ...48 2.13 Розробка технології ремонту та коригування виробу ...49 3 СПЕЦІАЛЬНА ЧАСТИНА...52 3.1 Опис реалізації поставленої задачі в системі автоматизованого проектування. ...52 3.2 Створення електричної схеми...53 3.3 Створення проекту друкованої плати ...57 4 ОХОРОНА ПРАЦІ ТА БЕЗПЕКА В НАДЗВИЧАЙНИХ СИТУАЦІЯХ ...60 4.1 Вимоги техніки безпеки при регулюванні та обслуговуванні виробу...60 4.2 Вибір засобів пожежної сигналізації...62 4.3 Оцінка стійкості роботи підприємства в надзвичайних ситуаціях природного характеру...66 4.4 Підвищення стійкості роботи підприємства, безпечність і можливість інженерного комплекс у протистояти надзвичайним ситуаціям...69 ВИСНОВКИ.... 72 ПЕРЕЛІК ПОСИЛАНЬ ...74

Astrophysical phenomena such as self-annihilation of primordial black holes (PBHs), gamma ray bursts (GRBs), and supernovae are expected to produce single dispersed pulses detectable in the low end of the radio spectrum. Analysis of these pulses could provide valuable information about the sources, and the surrounding and intervening medium. The Eight-meter-wavelength Transient Array (ETA) is a radio telescope dedicated to the search for these pulses in an 18 MHz bandwidth centered at 38 MHz. ETA consists of 10 dual-polarized active dipoles providing an all-sky field of view. This thesis describes the results of a search campaign using ETA, namely, a Crab giant pulse (CGP) search. CGPs are already known to exist, and thus provide an excellent diagnostic for system performance. We found 11 CGP candidates in 14 hours of data. Although there has not been a single compelling detection (signal-to-noise ratio > 6), our analysis shows that at least a few of these candidates may be CGPs. We also explain the analysis preparation for PBH and GRB searches. Additionally, we describe the instrument and a software "toolchain" developed for the analysis of data that includes calibration, radio frequency interference (RFI) mitigation, and incoherent dedispersion. A dispersed pulse simulation code was developed and used to test the toolchain. Finally, improvements are suggested.
Master of Science

Проведено аналіз методів та засобів вимірювання частоти. Обґрунтовано вибір інтервального методу вимірювання частоти. Вимірюваний сигнал перетворюється в послідовність імпульсів і вимірюється період їх слідування. На базі проведеного аналізу розроблено схеми електричну структурну частотоміра. Розроблено схему електричну принципову та проведено розрахунок каскадів. Розроблено алгоритм роботи лічильника періоду, відображення інформації та управління частотоміром. Частотомір управляється однією кнопкою. Технічні параметри частотоміра: Максимальна вимірювана частота 30 МГц; Максимальний крок вимірювання частоти 6 Гц; Чутливість по входу 250 мВ; Точність вимірювання частоти 0,01 Гц.
The analysis of methods and means of frequency measurement is carried out. The choice of interval method of frequency measurement is substantiated. The measured signal is converted into a sequence of pulses and the period of their following is measured. On the basis of the conducted analysis schemes of electric structural frequency meter are developed. An electrical circuit diagram has been developed and cascades have been calculated. An algorithm for the operation of the period counter, information display and frequency meter control has been developed. The frequency meter is controlled by one button. Technical parameters of the frequency meter: The maximum measured frequency is 30 MHz; Maximum frequency measurement step 6 Hz; Input sensitivity 250 mV; Frequency measurement accuracy 0.01 Hz.
Перелік умовних позначень, символів, одиниць, скорочень і термінів 7 Вступ 8 1 Основана частина 10 1.1 Аналіз технічного завдання 10 1.2 Обґрунтування методу вимірювання частоти 10 1.3 Схема електрична структурна 14 1.3.2 Розрахунок конденсаторів індивідуальної розв’язки 22 1.3.3 Вибір конденсаторів групової розв’язки живлення 23 1.3.4 Розрахунок елементів вхідного кола 24 1.4 Проектування програмне 32 1.4.1 Розробка алгоритму роботи мікроконтролера 32 1.5 Програма управління семисегментним індикатором 35 1.6 Конструкція друкованого вузла 43 2 Безпека життєдіяльності, основи охорони праці 46 2.1 Планування робіт з охорони праці та контроль за їх безпекою 46 2.2 Проведення аварійно-відновлювальних робіт на лініях і об’єктах зв’язку, радіомовлення і телебачення 49 Висновки 51 Список використаних джерел 52 Додатки 53

Робота виконана на кафедрі автоматизації технологічних процесів і виробництв факультету прикладних інформаційних технологій та електроінженерії Тернопільського національного технічного університету імені Івана Пулюя Міністерства освіти і науки України. Захист відбудеться «25» червня 2021 р. о 9.00 год. на засіданні екзаменаційної комісії №21 у Тернопільському національному технічному університеті імені Івана Пулюя
В кваліфікаційній роботі розроблено акустичний вимірювач переміщення механічних об'єктів. Основне завдання розробки полягає в тому, щоб зробити цей пристрій зручним у використанні, дешевим і надійним. Використання цього пристрою надає можливість виміряти відстань або рух механічних об'єктів у важкодоступних місцях. Пристрій значно зменшить трудомісткість в вимірі і отриманні оперативної інформації про рух механічних об'єктів. Введення цього пристрою дозволить значно скоротити час і підвищити точність вимірювань.
The acoustic measuring device of moving of mechanical objects was developed in this diploma project. The basic task of development consists in that, to do this device comfortable in the use, cheap and reliable. The use of this device enables to measure distance or motion of mechanical objects in difficult of access places. A device is given considerably will decrease hand expenses at measuring and receipts of operative information about motion of mechanical objects. Introduction of this device will allow considerably to shorten time, and will promote exactness at measuring.
ПЕРЕЛІК УМОВНИХ ПОЗНАЧЕНЬ І СКОРОЧЕНЬ 6 ВСТУП 7 1 АНАЛІТИЧНА ЧАСТИНА 9 1.1 Загальні теоретичні відомості 9 1.2 Частотний метод вимірювання відстані 10 1.3 Теоретичні відомості про генератори 13 2 ПРОЕКТНА ЧАСТИНА 16 2.1 Вибір та обґрунтування схеми приладу 16 2.2 Вибір частотоміра 27 2.3 Розрахунок елементів пристрою 30 2.4 Опис роботи принципової схеми 44 3 СПЕЦІАЛЬНА ЧАСТИНА 48 3.1 Опис схеми змодельованої в Micro-Cap 7 48 4 БЕЗПЕКА ЖИТТЄДІЯЛЬНОСТІ, ОСНОВИ ОХОРОНИ IIРАЦІ 51 4.1 Значення охорони праці для забезпечення безпечних умов праці 51 4.2 Аналіз потенційних небезпек та шкідливостей виробничої сфери 52 4.3 Електромагнітне й іонізуюче випромінювання 54 4.4 Забезпечення нормальних умов праці 55 4.5 Розрахунок напруги дотику 60 ВИСНОВКИ 63 ПЕРЕЛІК ПОСИЛАНЬ 64

Пояснювальна записка містить: сторінок 81, рисунка 36, таблиць 21, джерел літератури 12. Об’єктом дослідження роботи є біноміальний пристрій для вимірювання частоти. Мета роботи розробити цифровий частотомір на основі завадостійкого лічильника біноміальних кодів, який здатен працювати в умовах з високим рівнем завад. Вимірювання частоти сигналів дуже часто використовується у виробництві. На результати вимірювання цифрових частотомірів, впливають завади які діють на внутрішні компоненти пристрою, через їх вплив може бути отримане значення яке не відповідає дійсному. Тому актуальним завданням є підвищення завадостійкості компонентів і приладів в цілому. В цифрових частотомірах основним вузлом, що відповідає за точність є лічильник. В більшості випадках в якості лічильника використовують двійкові лічильники, які мають досить прості за будовою, але вони зазвичай не мають пристрою контролю, який здатен виявляти і виправляти помилки, які виникають під впливом електромагнітного випромінювання. Для зменшення впливу завад на результати роботи електронних пристроїв використовують різноманітні методи, серед них: застосування індивідуальних згладжуючих конденсаторів, використання фільтрів, екранування. В даній роботі запропоновано використання лічильника біноміальних кодів, який здатен працювати в умовах з високим рівнем завад. Ключові слова: завадостійкість, біноміальний, лічильники, частота, перешкоди.

This master’s thesis is dealing with remote measuring systems and their utilization in power engineering. In the first part there are described requirements on an autonomous measuring system and description of AMM and AMR systems. Communicating and data flows working on accurately defined communicating layers are also depicted in this part. The attention is devoted to the possibility of data processing and functions of devices offered by these attributes. In the following part there are described reasons for utilization of remote measuring systems in power engineering and the main advantages of connection of more devices into one unit. After finding of required parametres and functions of systems, a suggestion of terminal device is created in the same way. The suggestion is described in the measuring part with A/D converter, processing in microprocessor, measuring and evaluating alogorithms and attributes of communication of bus used. The last part is devoted to utilization of remote analysis in small power stations in dispersed production. Formation of deformation of voltage, harmonic analysis of signal and its application for data processing are described there. Described analysis was tested on data acquired from a cogeneration unit.

In this thesis, the conventional low voltage power line communication methods is investigated in the axis of automated meter reading applications and the classification and experimental verification of common noise types for low voltage power line communication network. The investigated system provides the real time transmission of electricity consumption data recorded by electricity meters, initially to a local computer via a low voltage line through a low speed PLC (Power Line Carrier) environment and subsequently to a corporate network through a high speed data transmission medium. The automated meter system provides a more effective tracking and data acquisition, a more detailed and vigorous knowledge about consumer behavior for subscriber assessment in electricity distribution in association with a brand new management and system supervision concept in electricity distribution control and management technology. The theoretical studies are experimentally verified for the Turkish low voltage power infrastructure through laboratory experiments performed in METU Electrical and Electronics Engineering Department, Electrical Machines and Drives Laboratory and R&
D Laboratories of MAKEL facilities in Hadimkö
y. The single phase voltage of the mains line between the phase and neutral is monitored to exhibit the disturbing effects of various noise sources. The resulting voltage spectrum is logged by using digital data acquisition devices in time and frequency domain. The waveforms are converted to frequency domain using the Fast Fourier Transform (FFT) functions of the MATLAB. The experimental results are compared to the theoretical findings obtained through literature survey.

This master’s thesis deals with grid dip meter, its operating principle, characteristics and with measuring procedure. The thesis contains basic division of oscilators, its characteristics and operating principal. The master`s thesis contains complete design of grid dip meter with large-diameter measuring coil which is placed outside the device. Grip dip meter is made of SMD components on a one-sided printed wiring. Grip dip meter consist of transformer itself, that has two secondary windings as a supply for resonance meters and internal digital frequency meter. The device has analog panel gauge and BNC input for extrenal counter.

A load control scheme that used frequency measurements of a smart meter for controlling domestic appliances to provide primary response was investigated. An experimental rig was developed to test and demonstrate the scheme. The amount of loads to be controlled to limit the frequency drop of the Great Britain (GB) power system to a set of minimum allowable frequencies was found. Operating speeds and the limitations of the components of the load controller in providing primary response are discussed. It is shown that if smart meters are to play any role in primary response then the speed at which the system frequency is measured must be increased very considerably. Load profile of fridges/freezers, washers/dryers and hobs/ovens in the GB power system were constructed. Then the percentages of appliances required to be in the load control scheme to shed the estimated amount of controllable loads, were calculated. It is found that the total controllable load requirement can be provided using fridges and freezers alone. Since many washers/dryers and hobs/ovens do not operate at night, they can not then provide a significant amount of controllable loads. However, using these appliances in the day time, the amount of fridges and freezers in the load control scheme can be reduced significantly. The ability of the proposed smart metering system in the UK to report available demand response from the appliances to the network operator was investigated. It was found that the communication network would not support reporting demand response in near real-time. Using load profiles of appliances for 40,000 houses, it was shown that by installing aggregation devices at distribution transformers and substations, the demand response can be reported to the network operator every minute. By aggregating and sending changes only, the impact of reporting demand response in near real-time on communication network reduces significantly. The ability of a state estimator to estimate distribution network voltages using smart meter measurements obtained on the previous day was evaluated. The improvement 10 of the accuracy of the estimated voltages with the number of nodes providing near real-time measurements obtained from distributed generators was also investigated. It was found that when the voltages are estimated using the previous day’s measurements without using any near real-time measurement, the voltage error at all nodes were high. By using near-real time measurements obtained from distributed generators, the error can be reduced significantly.

El món de les comunicacions per la xarxa elèctrica (CXE) pot ser dividit en tres grans tipus: CXE en baix voltatge (CXE-BV), en mig voltatge (CXE-MV) i en alt voltatge (CXE-AV). En aquests últims anys, les CXE-BV han atret una gran expectació, ja que les seves capacitats han fet d'aquesta tecnologia una bona opció com alternativa pel bucle local d'accés i pel desplegament de xarxes d'àrea local, focalitzades aquestes últimes en l'entorn domèstic. A més, les CXE-BV inclouen un conjunt d'aplicacions de baixa velocitat orientades a l'operador, com la lectura automàtica de comptadors (LAC), distribució de càrrega, facturació dinàmica, etc. Per altra banda, les CXE-MV i CXE-AV, històricament lligades a tasques de telecontrol i teleprotecció, s'estan començant a considerar com un canal de comunicacions eficient i fiable. El desenvolupament de sistemes digitals i els esforços d'estandardització estan fent d'aquests canals un medi atractiu per a que els operadors elèctrics ofereixin serveis de comunicacions, ja que no necessiten invertir en infraestructura perquè la xarxa elèctrica ja està desplegada.
En aquesta Tesi s'introduiran i es comentaran les particularitats de les tres xarxes elèctriques, després, es mostraran al lector les solucions tecnològiques existents pels canals de BV basats en la norma Europea CENELEC així com pels canals d'AV, mostrant que els sistemes actuals de LAC ofereixen una diversitat freqüencial molt baixa i que els mòdems CXE-AV estan ancorats en estendards antiquats.
Aquest treball es mou per les tres topologies de la xarxa, particularment, en aplicacions orientades a la banda CENELEC, en mesura i modelat de canal, i en mesura i disseny del nivell físic per sistemes CXE-BV, CXE-MV i CXE-AV respectivament. Els sistemes actuals que exploten la banda CENELEC ofereixen mecanismes d'explotació de la diversitat freqüencial del canal molt limitats o nuls, donant lloc a una baixa robustesa en front a interferències i soroll de fons acolorit. Aquest treball proposa un esquema de modulació multiportadora que, mantenint una complexitat baixa, ofereix unes altes prestacions permetent un bon nivell d'explotació de la selectivitat freqüencial. Per al que a CXE-MV respecta, aquesta Tesi desenvolupa un model de canal determinístic-estadístic pels anells urbans de distribució de potència i, finalment, en sistemes CXE-AV, aquest treball proposa, basat en mesures de canal i proves de camp, un nivell físic de banda ampla capaç de incrementar la velocitat de comunicació mentre manté una baixa densitat espectral de potència limitant així la interferència a altres sistemes.
PARAULES CLAU: Power line communications (PLC), low voltage (LV), medium voltage (MV), high voltage (HV), automatic meter reading (AMR), orthogonal frequency division multiplexing (OFDM), multicarrier spread spectrum (MC-SS), communication system design, channel measurements, channel modeling, scattering parameters.
El mundo de las comunicaciones por la red eléctrica (CRE) puede ser dividido en tres grandes tipos: CRE en bajo voltaje (CRE-BV), en medio voltaje (CRE-MV) y en alto voltaje (CRE-AV). En estos últimos años, las CRE-BV han atraído una gran expectación, ya que sus capacidades han hecho de esta tecnología una buena opción como alternativa para el bucle local de acceso y para el despliegue de redes de área local, focalizadas estas últimas en el entorno doméstico. Además, las CRE-BV incluyen un conjunto de aplicaciones de baja velocidad orientadas al operador como la lectura automática de contadores (LAC), distribución de carga, facturación dinámica, etc. Por otro lado, las CRE-MV y CRE-AV, históricamente ligadas a tareas de telecontrol y teleprotección, se están empezando a considerar como un canal de comunicaciones eficiente y fiable. El desarrollo de sistemas digitales y los esfuerzos de estandarización están haciendo de estos canales un medio atractivo para que los operadores eléctricos ofrezcan servicios de comunicaciones, ya que no necesitan invertir en infraestructura porque la red eléctrica ya está desplegada.
En esta Tesis se introducirán y se comentarán las particularidades de las tres redes eléctricas, luego, se mostrarán al lector las soluciones tecnológicas existentes para los canales de BV basados en la norma Europea CENELEC así como para los canales de AV, mostrando que los sistemas actuales de LAC ofrecen una diversidad frecuencial muy baja y que los módems CRE-AV están anclados en estándares anticuados.
Este trabajo se mueve por las tres topologías de red, particularmente, en aplicaciones orientadas a la banda CENELEC, en medida y modelado de canal, y en medida y diseño del nivel físico para sistemas CRE-BV, CRE-MV y CRE-AV respectivamente. Los sistemas actuales que explotan la banda CENELEC ofrecen mecanismos de explotación de la diversidad frecuencial del canal muy limitados o nulos, dando lugar a una escasa robustez frente a interferencias y ruido de fondo coloreado. Este trabajo propone un esquema de modulación multiportadora que, manteniendo una complejidad baja, ofrece unas altas prestaciones permitiendo un buen nivel de explotación de la selectividad frecuencial. Por lo que a CRE-MV respecta, esta Tesis desarrolla un modelo de canal determinístico-estadístico para los anillos urbanos de distribución de potencia y, finalmente, en sistemas de CRE-AV, este trabajo propone, basado en medidas de canal y pruebas de campo, un nivel físico de banda ancha capaz de incrementar la velocidad de comunicación mientras mantiene una baja densidad espectral de potencia limitando así la interferencia a otros sistemas.
PALABRAS CLAVE: Power line communications (PLC), low voltage (LV), medium voltage (MV), high voltage (HV), automatic meter reading (AMR), orthogonal frequency division multiplexing (OFDM), multicarrier spread spectrum (MC-SS), communication system design, channel measurements, channel modeling, scattering parameters.
The world of Power line communications (PLC) can be divided into three main types: low voltage PLC (LV-PLC), medium voltage PLC (MV-PLC) and high voltage PLC (HV-PLC). These last years, LV-PLC has attracted a great expectation since its wideband capabilities has made this technology a suitable choice for last-mile access and in-home communications. Moreover, LV-PLC also includes a utility oriented low frequency and low speed applications, such as automatic meter reading (AMR), load distribution, dynamic billing and so on. On the other hand, MV-PLC and HV-PLC, historically oriented to teleprotection and telecontrol tasks, are being considered as a reliable communication channel. The development of digital equipment and the standardization efforts are making those channels an attractive medium for electrical utilities telecommunications services, since the network, as well as in LV-PLC, is already deployed.
In this PhD dissertation, the three different PLC topologies are reviewed and the different communications techniques in such channels exposed. Then, a deep technological review of existing AMR solutions for the European CENELEC band, as well as HV-PLC systems is given, showing that existing AMR systems deliver low frequency diversity and HV-PLC systems are anchored in old fashioned standards.
This work walks around the three topologies, specifically, CENELEC band utility oriented applications, channel measurement and modeling and channel measurement and physical layer design, regarding LV-PLC, MV-PLC and HV-PLC respectively. Existing CENELEC compliant systems deliver low or none frequency diversity mechanisms, yielding in a low robustness against colored noise and interference. This work propose a multicarrier based physical layer approach that, while keeping the complexity low, delivers high performance allowing a great level of frequency diversity. Focusing on MV-PLC, a hybrid deterministic-statistical channel model for urban underground rings is developed and, finally, in HV-PLC systems, this work proposes, based on measurements and field tests, a wideband physical layer in order to increase data rate while keeping low both the power spectral density and possible interference to other systems.
KEYWORDS: Power line communications (PLC), low voltage (LV), medium voltage (MV), high voltage (HV), automatic meter reading (AMR), orthogonal frequency division multiplexing (OFDM), multicarrier spread spectrum (MC-SS), communication system design, channel measurements, channel modeling, scattering parameters.

Optical frequency standards are necessary tools for accurate measurement of time and length. In practice these standards are stabilised laser systems locked to a known frequency reference. These references are typically the resonant frequencies of the atoms of an absorption medium that have been theoretically calculated to a high degree of accuracy. This thesis describes a combination of experimental and theoretical research performed on modulation transfer spectroscopy (MTS)--a technique used to frequency stabilise a laser in order to produce an accurate frequency reference--with emphasis placed on developing techniques and procedures to overcome the limitations found in existing MTS stabilised laser systems. The focus of the thesis is to generate a highly accurate frequency reference by researching the system parameters that will increase the signal to noise ratio and improve the accuracy of the reference through refinement of the signal structure. The early theoretical interpretation of MTS was effectively a low absorption approximation that occurs at low pressures. This approximation ignores the depletion of beam energy through absorption and is a distinct limitation of the theoretical model in its ability to accurately predict the influence of a range of system parameters on signal strength and structure. To overcome this limitation a 3-D (or volumetric) analysis was developed and is presented here for the first time. This volumetric model is a measure of two depleted beams interacting collinearly in an absorbing medium of iodine and is described to accurately predict the signal maximum as a function of pressure for all wavelengths. This model was found to be more accurate in predicting the influence of system parameters on the signal strength and structure, including that of pump beam intensity, pressure, saturation parameter, cell length and modulation parameters. The volumetric model is a novel approach to MTS theory but is more complex computationally than the traditional low pressure model and therefore more difficult to implement in many situations. To overcome this problem a hybrid model was developed as a combination of the low pressure and volumetric models. The comparison between the rigorous volume model and the hybrid model indicate that there is a deviation in the signal strength at high pressures. However, the agreement was very good in the pressure regimes that are commonly used to realise actual frequency references. Comparison of the hybrid model to experimental data was performed over a range of different wavelengths (532 nm, 543.5 nm, 612 nm and 633 nm) and found to be in close agreement. This gives confidence in the model to accurately predict signal strength and structure in any situation. Three mechanisms have been identified that limit the accuracy of frequency references due to the creation of residual amplitude modulation (RAM) where it shifts the frequency of the reference. The influence of RAM is included in the hybrid model as a ratio of the amplitude modulated and frequency modulated components of the saturating beam. These RAM production mechanisms result from the modulation of the saturating beam, the overlap of the beams in the medium, and the differential absorption of the sidebands in the medium. While the first mechanism has been previously reported the latter two are discussed here in detail for the first time. RAM generated by the modulators used (acousto-optic or electro-optic modulators) was typically of the order of 10% to 12%, depending on the excursion of the created sidebands. RAM generated by an asymmetric beam overlap with the modulators used was found to be as large as 30%. A combination of these two independent mechanisms can be used to provide a "RAM-free" state of the system by using one to cancel the effects of the other. The third RAM generation process--medium induced RAM--is difficult to remove but through a careful combination of absorption related parameters--namely, pump intensity, cell length, pressure and detector phase--the effects of RAM can be removed, leading to a distortion free MTS signal. Further investigation into the predictions provided by the hybrid model shows that there is a complex relationship between cell length and the optimum pressure required for maximum signal strength, such that longer cell lengths will not necessarily improve the signal strength. This is contrary to conventional thinking and is important in the MTS design process to reduce unnecessary costs and improve the signal to noise ratio and frequency accuracy. Optimisation of frequency stabilised laser systems using MTS are generally performed using trial and error. Comparison of these optimum parameter values to those predicted by the hybrid model show that for popular wavelengths such as 532 nm they are similar. In addition, the hybrid model is able to predict the frequency shifts that arise within the system parameters used and has shown that existing systems being used at 532 nm, 633 nm and 778 nm could improve their signal to noise ratio and accuracy through a variation in the parameters. A methodology based on the hybrid model is presented that can be used to calculate the optimum parameters for maximum signal strength and a "RAM-free" state for any wavelength. This systematic approach can therefore be used to guide the design of actual frequency stabilised laser systems prior to and during the design process.

Sulla base del modello proposto da Di Baldassarre et al. (2006), che utilizza la precipitazione media annuale (MAP) come proxy della posizione geografica, l’elaborato di Tesi si è posto come obiettivo quello di ricercare ulteriori proxy in grado di fornire una migliore previsione degli eventi estremi di precipitazione, in modo da migliorare la capacità di previsione del modello. Sono stati valutati il 95° percentile delle cumulate annue di precipitazione e il 95° percentile dei dati di precipitazione giornaliera, e per il calcolo degli L-momenti (v. Hosking e Wallis, 1993, 1997), momenti statistici di largo impiego in campo idrologico. È stato poi analizzato il legame tra ciascun proxy climatico e gli L-momenti, con lo scopo di valutare se, sulla base del modello proposto da Di Baldassarre et al. (2006) si ottengono significativi benefici. Ai fini dell’analisi sono stati impiegati due dataset, entrambi forniti da ARPAE (Agenzia regionale per la prevenzione, l'ambiente e l'energia dell´Emilia-Romagna): il dataset AMS fornisce i dati relativi alle serie dei massimi annuali di precipitazione per durate sub-giornaliere e sub-orarie, relativi alle stazioni pluviometriche che si trovano all’interno di bacini idrografici situati nell’area di pertinenza di ARPAE, per il periodo 1921-2018; il dataset PrecClima è un dataset climatico giornaliero di precipitazioni che copre tutto il territorio regionale (e dintorni) dal 1961 al 2018, ottenuto da ARPAE mediante interpolazione spaziale su una griglia regolare a partire dai valori rilevati dalla rete delle stazioni meteorologiche storiche. Esaminando i risultati ottenuti si può affermare che l’utilizzo di un proxy che fa riferimento a valori estremi, quali AP95 e DP95, non porta a miglioramenti significativi rispetto all’utilizzo di un proxy che tiene conto di un valore medio, in questo caso il MAP.

The contents of this thesis is design of audio power amplifier in Class D with fully digital control and remote control and is divided into two parts . The first part is devoted to the basic principles and theory of key elements of the entire amplifier. The second part consists of a complete description of the design and construction of a power amplifier, digital control with remote control, a spectrum analyzer, equalizer, preamp VU meters and complete power supply. Each proposal contains a detailed analysis of the solutions supported by simulations and software. For individual parts have been completely measured p arameters.

The big data framework applied to smart meters offers an exception platform for data-driven forecasting and decision making to achieve sustainable energy efficiency. Buying-in consumer confidence through respecting occupants' energy consumption behavior and preferences towards improved participation in various energy programs is imperative but difficult to obtain. The key elements for understanding and predicting household energy consumption are activities occupants perform, appliances and the times that appliances are used, and inter-appliance dependencies. This information can be extracted from the context rich big data from smart meters, although this is challenging because: (1) it is not trivial to mine complex interdependencies between appliances from multiple concurrent data streams; (2) it is difficult to derive accurate relationships between interval based events, where multiple appliance usage persist; (3) continuous generation of the energy consumption data can trigger changes in appliance associations with time and appliances. To overcome these challenges, we propose an unsupervised progressive incremental data mining technique using frequent pattern mining (appliance-appliance associations) and cluster analysis (appliance-time associations) coupled with a Bayesian network based prediction model. The proposed technique addresses the need to analyze temporal energy consumption patterns at the appliance level, which directly reflect consumers' behaviors and provide a basis for generalizing household energy models. Extensive experiments were performed on the model with real-world datasets and strong associations were discovered. The accuracy of the proposed model for predicting multiple appliances usage outperformed support vector machine during every stage while attaining accuracy of 81.65\%, 85.90\%, 89.58\% for 25\%, 50\% and 75\% of the training dataset size respectively. Moreover, accuracy results of 81.89\%, 75.88\%, 79.23\%, 74.74\%, and 72.81\% were obtained for short-term (hours), and long-term (day, week, month, and season) energy consumption forecasts, respectively.

The subject of graduation thesis is a design of line analyser according to standard EN61000-4-30 class A. The analyser is determine to be used for quality control of supplied electric power which is, during electric power transmission, affected by several disturbances. Power line analyser should measure single-phase and three-phase network parameters in LV and HV systems. Measured parameters can be shown on the full colour TFT display, stored in the device memory or sent to other devices such as PC. For communication between the device and PC the USB, Ethernet or RS485 interface are used.

碩士
義守大學
生物醫學工程學系
104
The Current research relates to ultrasound probes, which according to their application use different frequencies. In general, driving an ultrasound probe must find a suitable way to manually adjust the operating frequency of the probe, but it’s not convenient and accurate. However, in a suitable operating frequency, its power will become higher. Therefore, in this study, we designed a system that can adjust to a suitable and accurate operating frequency automatically. In this study, we developed a function generator using an AD5930 which can produce continuous or burst waveforms. The use of burst waveforms can prevent damage caused by overheat. The output signal is then fed to the inverter to adjust the signal amplitude according to the power supply voltage and drive the ultrasound transducer. A C++ produced software was used to upload parameters to an Arduino UNO microcontroller board so that it can program the AD5930 burst waveform generator to adjust the parameters of the output signal such as the frequency and the burst time. Using this hardware and software concept applied on different ultrasound transducers, we expect to expand the application of ultrasound transducers in the biomedical field. An Arduino microcontroller combined with the AD5930 circuit produces output digital and/or analog signals with stable frequency. The user can easily and conveniently adjust to a desired fixed output frequency or set an increasing sweep frequency. This type of device could be used in various ultrasonic probe applications.

碩士
國立體育學院
教練研究所
90
100-meter world records have been approaching human breaking point, and physical ability is no more critical point to win the game. Nowadays the training methods decide the championship and the agonistic achievement by using periodical technical ability. This research analyses and studies the movements by the average speed、the mean frequency and the mean distance of every 10-meter-section in the 100-meter-sprint and of the four periods. The four periods are: the first period — from 0 to 30 meters is called acceleration period; the second period — from 30 to 60 meters is called high-speed period; the third period — from 60 to 90 meters is called maintenance period; the last period — from 90 to 100 meters is called decelerate period. The research results are offered as reference to the sprinters and coaches to develop the techniques and to train or to adjust for the races. The results and advises of the research are as follows: 1. The average paces of the athletes achieve the highest at the distance of 60 meters. The speed drops immediate after entering maintenance period. The range that the speed drops is too big in decelerate period. 2. 400-meter-sprinters are better than 100-meter-sprinters in maintenance period; and it is more obvious in decelerate period. 3. The athletes should not straighten too early in the acceleration of head start because it would influence the fluency of the acceleration. It is better to straighten the body at around 20 to 30 meters. 4. During high-speed period, pull back the legs to bottom rim of the hips. Do not drag too long or flap too high. 5. When doing a 100 meter spring, the leg which is pushing should do the best to exceed the power in order to complete the movement and increase the horizontal distance of the body center. 6. In maintenance period, maintain as much time as possible for fast frequency of steps. The longer it lasts, the better achievement in the 100-meter run.

碩士
輔仁大學
電機工程學系
99
The main purpose of this study was to design a portable device for measuring the high frequency sound speed. In a general high frequency sound speed measured system, the sound speed was measured via a high speed A/D converter and processed by computer. However, this device only used analog components and micro-processor, and the advantages including low cost and real time display. This sound speed meter included a high frequency ultrasound pulser/receiver and a transducer with a center frequency of 42 MHz. The high frequency ultrasound pulser/receiver producted a native single pulse with -80 volt to excite high frequency ultrasound transducer and increased the ultrasound echo signal amplitude by 45 dB amplifier. The sound speed was measured by counting the timing between the analog pulse and reflect signal from the reflector by using a high speed counter and displayed by a LCD monitor. The device was tested by measuring the sound speed in water and blood. The measured results discussed the sound speed around 22℃ is difference between water and blood which speed is 1540 m/s and 1626 m/s, and were compared to the commercial device only 1% error was obtained. All the results indicated that this device can be used for measuring sound speed in real time.

碩士
國立成功大學
機械工程學系碩博士班
93
The Frequency-Shaping Sliding Mode Control (FSSMC) for high-speed active magnetic bearing (AMB) is synthesized. The controller is designed on the basis of the equation of motion of the magnetic bearing system, which composed the dynamics of the electrical sub-system and mechanical sub-system. By linear quadratic, optimal projection and frequency shaping methodology, FSSMC is proved to be asymptotica-lly stable as long as the uncertainties of system parameters are bounded. The main purpose of frequency-shaping design is to avoid excitation of high-order dynamics of the rotating spindle so that the effect of a low-pass filter is presented. For the AMB is Linear Parameter Varying (LPV) system, the Kharitonov’s Theorem is employed to examine the stability under variation of rotational speed. It is proved that the equivalent control for the speed-dependent AMB system is robust. The simulation results show that FSSMC performs rapid response to regulate the deviation of high-speed spindle within 1 um .

abstract: Flow measurement has always been one of the most critical processes in many industrial and clinical applications. The dynamic behavior of flow helps to define the state of a process. An industrial example would be that in an aircraft, where the rate of airflow passing the aircraft is used to determine the speed of the plane. A clinical example would be that the flow of a patient's breath which could help determine the state of the patient's lungs. This project is focused on the flow-meter that are used for airflow measurement in human lungs. In order to do these measurements, resistive-type flow-meters are commonly used in respiratory measurement systems. This method consists of passing the respiratory flow through a fluid resistive component, while measuring the resulting pressure drop, which is linearly related to volumetric flow rate. These types of flow-meters typically have a low frequency response but are adequate for most applications, including spirometry and respiration monitoring. In the case of lung parameter estimation methods, such as the Quick Obstruction Method, it becomes important to have a higher frequency response in the flow-meter so that the high frequency components in the flow are measurable. The following three types of flow-meters were: a. Capillary type b. Screen Pneumotach type c. Square Edge orifice type To measure the frequency response, a sinusoidal flow is generated with a small speaker and passed through the flow-meter that is connected to a large, rigid container. True flow is proportional to the derivative of the pressure inside the container. True flow is then compared with the measured flow, which is proportional to the pressure drop across the flow-meter. In order to do the characterization, two LabVIEW data acquisition programs have been developed, one for transducer calibration, and another one that records flow and pressure data for frequency response testing of the flow-meter. In addition, a model that explains the behavior exhibited by the flow-meter has been proposed and simulated. This model contains a fluid resistor and inductor in series. The final step in this project was to approximate the frequency response data to the developed model expressed as a transfer function.
Dissertation/Thesis
M.S.Tech Electrical Engineering 2013

"July 2003." Includes bibliographical references (leaves 459-484) Electronic publication; full text available in PDF format; abstract in HTML format. Details the application of a medium frequency Doppler radar to observations of meteorites entering the Earth's atmosphere. Techniques were developed that verified system performance was to specification Electronic reproduction.[Australia] :Australian Digital Theses Program,2001. xx, 485 leaves : ill. ; 30 cm.

碩士
國立宜蘭大學
電子工程學系碩士班
102
operation status of home appliances. The proposed system automatically identifies the electrical appliance in starting status. This method takes advantage of the combination of the fuzzy theory and neural network theory for system identification. The measurement of the RMS voltage, RMS current, RMS active power and the RMS apparent power are used for feature extraction by using a simple home Smart Meter with low sampling frequency. In this study, it shows 100% recognition rate in six experiments with different hybrid starting procedure.

Mesopause region winds have been measured by the low-frequency (LF) method at Collm until 2008. Since 2004, meteor radar (MR) measurements have been performed also. The LF and MR data set are combined to obtain a continuous time series of monthly zonal prevailing winds from 1979 through 2013 at about 90 km altitude. It has been found that, on a monthly time scale, the difference between zonal prevailing winds measured by LF and MR are small. During the 35-yr time interval considered, the zonal winds show positive trends towards more westerly winds throughout the year except for spring. There is a tendency that in spring and summer the trends are changing from more positive to small or negative after 1995. There is a possible influence of the 11-year solar cycle, most visible during early summer and early winter, and the effect weakens during recent years.

Fire is the primary natural disturbance vital to the ecological integrity of Quetico Provincial Park, Ontario, Canada. A new provincial park planning process (i.e., Class Environmental Assessment) has required the review of Quetico’s Fire Management Plan. To support this review, large and severe (stand-replacing) Quetico fires were studied using 1966 Ontario Ministry of Natural Resources (OMNR) forest resource inventory (FRI) mapping. A Geographic Information Systems (GIS) database of the FRI was created and updated with the OMNR digital fire atlas. This database was used as a time-since-fire and fire interval dataset to estimate fire frequency. It also served to archive the 1966 FRI for the largest protected area in the transition between the Boreal and Great Lakes-St. Lawrence forest regions. Non-parametric (Kaplan-Meier) survival analysis was used to estimate survival functions and mean fire intervals (i.e., the expected time between two consecutive stand-replacing fires for any location within the Park). Previous studies that have used Kaplan-Meier survival analysis methods have based fire frequency estimates solely on time-since-fire data. However, time-since-fire data cannot be equated with fire interval data when using non-parametric methods. At least one fire interval is required to obtain reliable results. The mean fire interval for the entire 475,782 ha Park between the years 1668 and 2007 was 230 years. Performing the analysis on various geographic and temporal partitions revealed fire frequency spatial and temporal variability. A constant (independent of time-since-fire) probability of burning was not observed for Quetico which is contrary to accepted conjecture for northwestern Ontario boreal/mixed-wood forests. A current fire cycle was also estimated for the Park (342 years) using the digital fire atlas. The results suggested that use of historical static fire frequency estimates as fire management prescriptions may not be justified given considerable fire frequency temporal variability. The observed fire frequency spatial variability suggests that studies should be undertaken at coarser scales than is the norm to characterise the regions fire regime in support of landscape level fire management planning.