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Relevant bibliographies by topics / Phase-frequency characteristic

Academic literature on the topic 'Phase-frequency characteristic'

Author: Grafiati

Published: 30 May 2022

Last updated: 31 May 2022

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Journal articles on the topic "Phase-frequency characteristic"

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Shakurskiy, M. V., and V. I. Volovach. "Mathematical model of digital frequency-sampling filters with shiftable phase-frequency characteristic." Radioelectronics and Communications Systems 59, no. 9 (September 2016): 397–401. http://dx.doi.org/10.3103/s0735272716090028.

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Cao, Xiaobin, Zhongmei Li, and Shiwei Yao. "Analysis on the Phase Frequency Characteristic of Soil Impedance." Energy and Power Engineering 10, no. 04 (2018): 17–24. http://dx.doi.org/10.4236/epe.2018.104b003.

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Паровик, Р. И. "Анализ добротности вынужденных колебаний дробного линейного осциллятора." Журнал технической физики 90, no. 7 (2020): 1059. http://dx.doi.org/10.21883/jtf.2020.07.49436.233-19.

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Using the harmonic balance method, analytical formulas are obtained for calculating the amplitude-frequency and phase-frequency characteristics, as well as the quality factor of the forced oscillations of a linear fractional oscillator. It was established that the characteristics under study depend on the dissipative properties of the medium - memory effects, which are described by derivatives of fractional orders. It is shown that fractional orders affect the attenuation of the oscillatory process and are associated with its quality factor. The calculated curves of the characteristics of the forced oscillations of a linear linear fractional oscillator showed that fractional orders can be considered as control parameters of the oscillatory process in a dissipative medium. Key words: quality factor, amplitude-frequency characteristic, phase-frequency characteristic, fractional derivatives, memory.

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Chu, Hai Rong, Bo Liu, and Yue Zhang. "Three-Loop Autopilot Frequency Characteristic Measurement." Applied Mechanics and Materials 494-495 (February 2014): 1332–34. http://dx.doi.org/10.4028/www.scientific.net/amm.494-495.1332.

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In order to measurement frequency characteristic of the missile three loop autopilot, three loop autopilot system model of the missile pitch channel was established. Then the autopilot system open-loop model was analyzed , and also open-loop frequency calculation formula was deduced. On the basis of the autopilot system model, half physical frequency characteristic measurement system was built, and the experimental data were processed by using correlation analysis method. Experimental results shows that when the time delay of measurement system was compensated, three loops autopilot actual cut-off frequency was 47.5rad/s, phase margin was 93°, amplitude margin was infinte, compared with the theoretical value, errors was less than 5%. The correctness of three loops autopilot frequency characteristic measurement method was verified.

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CHOI, MI-HYUN, and SOON-CHEOL CHUNG. "EXTRACTION OF COGNITIVE CHARACTERISTIC FUNCTIONS ACCORDING TO VARIOUS PARAMETER CHANGES OF VIBRATORY STIMULATION." Journal of Mechanics in Medicine and Biology 19, no. 08 (December 2019): 1940052. http://dx.doi.org/10.1142/s0219519419400529.

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In this study, vibratory stimuli with various intensities (four levels) and frequencies (10, 50, 100, 150, 200, 225, 250 and 300[Formula: see text]Hz) were applied to the right index finger to extract cognitive characteristic functions for the intensity and frequency. For subjective assessment, an experiment was conducted with 30 healthy adults in their twenties who were right-handed and had normal cognitive function. One trial of the experiment was composed of a vibration phase (0.1 s) and a rest phase (10 s). After vibration simulation was applied once for each intensity and frequency, the participants filled out a subjective assessment form. After extracting the score of each word, the cognitive characteristic function was derived through discriminant analysis and regression analysis according to the frequency and intensity. Through the cognitive characteristic function, the level of cognitive characteristics of each word can be investigated according to the influence of the frequency and intensity. The results observed through the cognitive characteristics function of each word showed that the words affected by the frequency and intensity were “light,” “thick,” “heavy,” “blunt,” “vibrating,” “fast” and “weak.” “Itchy” and “slow” were cognitive characteristics affected only by the frequency, and “strong” and “push” were affected only by the intensity. Through the vibratory stimulation presentation parameters, i.e., frequency and intensity, the results capable of predicting the degrees of various cognitive characteristics were presented.

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Dong, Jun, Zhong-gui Lu, Zhi-hong Sun, Zhi-tao Peng, Yan-wen Xia, Jing-qin Su, Feng Jing, Hao-yu Yuan, Hua Liu, and Jun Tang. "Transforming characteristic of phase-shift from frequency-domain to time-domain in frequency-domain holography." Optics & Laser Technology 44, no. 3 (April 2012): 594–99. http://dx.doi.org/10.1016/j.optlastec.2011.08.027.

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Parovik, Roman. "Frequency characteristics of the fractional oscillator Van der Pol." E3S Web of Conferences 127 (2019): 02010. http://dx.doi.org/10.1051/e3sconf/201912702010.

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Into this paper, the amplitude-frequency and phase-frequency characteristics of the Van der Polar fractional oscillator are studied in order to establish their relationship with the orders of fractional derivatives included in the model equation. Using the harmonic balance method, analytical formulas were obtained for the amplitude-frequency, phase-frequency characteristics, as well as the quality factor – the energy characteristic of the oscillatory system. It was shown that the quality factor depends on the orders of fractional derivatives, and change in their values can lead to both an increase and a decrease in the quality factor.

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Wei, Jin Cheng, and Jin Li. "Dynamic Modulus Characteristic of Large Stone Permeable Asphalt Mixtures." Applied Mechanics and Materials 423-426 (September 2013): 1110–13. http://dx.doi.org/10.4028/www.scientific.net/amm.423-426.1110.

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To study the dynamic modulus characteristic of LSPM mixes, dynamic modulus test was conducted for Large Stone Permeable Asphalt Mixtures (LSPM ) with neat asphalt and with modified asphalt and the range of dynamic modulus values for LSPM was determined and the dynamic modulus master curves were developed. The magnitude of the dynamic modulus decreased with an increase in temperature and increased with an increase in the frequency. The phase angle decreased as the frequency increased at low temperature. With temperature increase, there was a transition interval, where the phase angle increased up to frequencies of 0.5 Hz, and then it started to decrease as frequency increased. After the transition interval, the phase angle increased with an increase in frequency. Master curves developed by sigmoidal function showed that LSPM with modified asphalt exhibited higher dynamic modulus values at middle and high frequencies and lower dynamic modulus values at low frequencies.

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Иванов, В. В., Я. В. Еремина, and С. В. Ермолова. "Computer modeling of parametric converters with frequency and phase control." Informacionno-technologicheskij vestnik, no. 2(24) (June 17, 2020): 96–106. http://dx.doi.org/10.21499/2409-1650-2020-24-2-96-106.

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Осуществлено математическое моделирование параметрических преобразователей, использующих режим повышенной чувствительности. Названный режим преобразователей позволяет повысить эксплуатационные показатели аппаратуры авиационно-космических систем. Показано, что преобразователи с фазовым управлением обладают линейными характеристиками и являются более перспективны. Применение в них цифровых фильтров ведет к повышению стабильности частоты и точности настройки, а также минимизируется погрешность характеристики преобразования. Mathematical modeling of parametric converters using high-sensitivity mode is carried out. The named mode of converters allows to increase operational parameters of the equipment of aerospace systems. It is shown that phase-controlled converters are more promising because they have linear characteristics and allow the use of digital filters, which leads to an increase in frequency stability and accuracy of adjustment, and also minimizes the error of the conversion characteristic.

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Demyanov, Vladislav, Ekaterina Danilchuk, Yury Yasyukevich, and Maria Sergeeva. "Experimental Estimation of Deviation Frequency within the Spectrum of Scintillations of the Carrier Phase of GNSS Signals." Remote Sensing 13, no. 24 (December 10, 2021): 5017. http://dx.doi.org/10.3390/rs13245017.

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The term deviation frequency (fd) denotes the boundary between the variable part of the amplitude and phase scintillation spectrum and the part of uninformative noises. We suggested the concept of the “characteristic deviation frequency” during the observation period. The characteristic deviation frequency is defined as the most probable value of the deviation frequency under current local conditions. Our case study involved GPS, GLONASS, Galileo and SBAS data under quiet and weakly disturbed geomagnetic conditions (geomagnetic storm on 16 April 2021, Kpmax = 5, SYM-Hmin = −57 nT) at the mid-latitude GNSS station. Our results demonstrated that the deviation frequency for all signal components of GPS, GLONASS and Galileo varies within 15–22 Hz. The characteristic deviation frequency was 20 Hz for the mentioned GNSS signals. The SBAS differs from other systems: deviation frequency varies within 13–20 Hz. The characteristic deviation frequency is lower and equal to 18 Hz. We suggest the characteristic deviation frequency to determine the optimal sampling rate of the GNSS carrier phase data for the ionospheric studies. In turn, the deviation frequency can be considered as a promising index to estimate the boundary of non-variability of the ionosphere.

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Dissertations / Theses on the topic "Phase-frequency characteristic"

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Lehmann, Jessica Frida-Anita [Verfasser], Hartmut [Akademischer Betreuer] Führ, and Hermann [Akademischer Betreuer] Wagner. "Characteristic Delay and Characteristic Phase in Broadband Interaural Time Difference Tuning Curves Arising by Across-Frequency Integration / Jessica Frida-Anita Lehmann ; Hartmut Führ, Hermann Wagner." Aachen : Universitätsbibliothek der RWTH Aachen, 2015. http://d-nb.info/1129176681/34.

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Beyer, Matthias, Dirk Lucas, Heiko Pietruske, and Lutz Szalinski. "Two-Phase Flow Experiments on Counter-Current Flow Limitation in a model of the Hot Leg of a Pressurized Water Reactor (2015 test series)." Helmholtz-Zentrum Dresden-Rossendorf, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-216094.

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Counter-Current Flow Limitation (CCFL) is of importance for PWR safety analyses in several accident scenarios connected with loss of coolant. Basing on the experiences obtained during a first series of hot leg tests now new experiments on counter-current flow limitation were conducted in the TOPFLOW pressure vessel. The test series comprises air-water tests at 1 and 2 bar as well as steam-water tests at 10, 25 and 50 bar. During the experiments the flow structure was observed along the hot leg model using a high-speed camera and web-cams. In addition pressure was measured at several positions along the horizontal part and the water levels in the reactor-simulator and steam-generator-simulator tanks were determined. This report documents the experimental setup including the description of operational and special measuring techniques, the experimental procedure and the data obtained. From these data flooding curves were obtained basing on the Wallis parameter. The results show a slight shift of the curves in dependency of the pressure. In addition a slight decrease of the slope was found with increasing pressure. Additional investigations concern the effects of hysteresis and the frequencies of liquid slugs. The latter ones show a dependency on pressure and the mass flow rate of the injected water. The data are available for CFD-model development and validation.

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Черченко, Максим Олександрович. "Пристрої НВЧ на основі тонких діелектричних резонаторів." Master's thesis, Киів, 2018. https://ela.kpi.ua/handle/123456789/25868.

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Актуальність теми Застосування діелектричних резонаторів в електроніці НВЧ сприяє створенню високоефективних резонансних пристроїв. Вдосконалення характеристик цих систем є актуальною задачею. Зв'язок роботи з науковими програмами, планами, темами. Робота пов’язана з науковими програмами, планами та темами що розроблюються на кафедрі. Мета і задачі дослідження. Метою даної робити є вдосконалення пристроїв НВЧ на основі тонких діелектричних резонаторів. Для досягнення мети, необхідно виконати наступні задачі: 1. Проаналізувати існуючі структури НВЧ. 2. Дослідити структури НВЧ на основі тонких діелектричних резонаторів. 3. Показати перспективність конструювання пристроїхв НВЧ на основі тонких діелектричних резонаторів. Об’єктом дослідження є структури НВЧ на основі тонких діелектричних резонаторів. Предметом дослідження є електродинамічні властивості і характеристики тонких діелектричних резонаторів. Методика наукового дослідження включає: методи аналізу НВЧ-пристроїв, аналітичне моделювання. Практичне значення одержаних результатів. Запропоновано конструкції керованого фазообертача на основі тонких діелектричних резонаторів, що дозволило знизити керуючу напругу. Особистий внесок здобувача: • Експериментально досліджено електродинамічні характеристики фазообертачів на основі тонких діелектричних резонаторів. • Запропоновано конструкції фазообертачів із зниженою керуючою напругою. Структура і об'єм роботи. Робота складається зі вступу, шістьох розділів, висновків та списку використаних джерел. Загальний обсяг дисертації становить 76 сторінки. Робота включає 16 рисунків, 29 таблиць, список використаних джерел з 26 найменувань.
Actuality of theme The use of dielectric resonators in microwave electronics helps to create highly effective resonance devices. Improving the characteristics of these systems is an urgent task. Relationship of work with scientific programs, plans, themes. The work is connected with the scientific programs, plans and themes that are being developed at the department. The purpose and tasks of the study. The purpose of this work is to improve the microwave devices based on thin dielectric resonators. To achieve the goal, you need to accomplish the following tasks: 1. Analyze existing microwave structures. 2. To study the microwave structure on the basis of thin dielectric resonators. 3. Show the prospect of designing devices on microwave based on thin dielectric resonators. The object of the study is the structure of microwave based on thin dielectric resonators. The subject of the study is electrodynamic properties and characteristics of thin dielectric resonators. The method of scientific research includes: methods of analysis of microwave devices, analytical modeling. The practical value of the results. The designs of a controlled phase rotator on the basis of thin dielectric resonators were proposed, which allowed to reduce the control voltage. The applicant's personal contribution: • Electrodynamic characteristics of phase rotators on the basis of thin dielectric resonators have been experimentally investigated. • The designs of phase rotators with reduced control voltage are proposed. Structure and volume of work. The work consists of an introduction, six sections, conclusions and a list of sources used. The total volume of the dissertation is 76 pages. The work includes 16 drawings, 29 tables, list of used sources from 26 titles.

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Slavíček, Ondřej. "Dynamické charakteristiky běžně používaných snímačů tlaku." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-254445.

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This thesis deals with the dynamic properties of electric pressure transducers. These are properties that are reflected in the measurement of rapid, time-dependent processes. They could be described in two ways. Either by using amplitude and phase frequency response characteristics, or just one particular value. Natural frequency, cutoff frequency or time constant. These parameters indicate the extreme values for the use of measuring devices in the measurement of time-dependent processes. In this work will be described procedures for determining these parameters.

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Tahir, Muhammed Imran. "Frequency and phase locking of a CW magnetron : with a digital phase locked loop using pushing characteristics." Thesis, Lancaster University, 2008. http://eprints.lancs.ac.uk/76594/.

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The main body of work presented in this thesis is precise frequency and phase control of a 1.2 kW CW cooker magnetron (National 2M137) locked to a 10 MHz reference injected with a very small RF signal (of the order of -40 dBc) creating a suitable RF source for particle accelerators and other sophisticated applications. We will go on to discuss the characterization of the magnetron with differing heater powers and load conditions when operated with a low cost switched mode power supply. We similarly identify three different regimes of the magnetron operation with respect to the heater power: firstly low noise operation for small heater powers (up to 15W), secondly unstable operation for mid-range heater powers (15W to 30W) and thirdly high noise operation at high heater powers (30W to 54W). We then introduce a novel method to lock the magnetron output frequency to the 10 MHz reference using a digital frequency synthesizer IC (Analog Devices ADF4113) in a negative feedback loop, with this method we exploit the use of the pushing mechanism where the ADF41113 controls the power supply output to vary the magnetron’s anode current, keeping its natural frequency locked to the reference. We next investigate the injection locking of the frequency locked magnetron with small injection levels (-29 dBc to -43 dBc) under differing operating conditions and observe a phase jitter performance of the order of+/-13 o for very small heater power and -29 dBc injection level. We then fast switch/ramp the injection phase and establish the maximum rate of change of the magnetron output phase. This rate was found to be 4p/us for -29 dBc injection level and 44W heater power. We finally discuss the implementation of a fast DSP based feedback control on the injection phase to improve the magnetron phase jitter performance to below 1o r.m.s.

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Neužil, Jan. "Uživatelské rozhraní pro HP89410A." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-217775.

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The aim of this thesis was to develop user interface in LabVIEW to make typical measurements with spectral analyzer HP89410A There is introduced the theory of operation of an analogue heterodyne and a digital FFT spectral analyzer. It is explained the background of the Fast Fourier Transform. There are discussed the key settings in measuring with FTT analyzer, like window function, bandwidth, number of frequency points, or the averaging. Further is described the program, which was developed for measuring frequency characteristic by white noise and by stepped measurement. It was also made a module for measuring Signal to Noise Ratio and module for Total Harmonic Distortion. In the last part of this thesis are shown the results of processed exemplar measurements.

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Дубицька, Марія Сергіївна, Мария Сергеевна Дубицкая, and M. S. Dubyts’ka. "Вдосконалення способу прогнозу диз’юнктивних порушень методом акустичної геолокації при відпрацюванні пологозалягаючих вугільних пластів." Thesis, Видавництво НГУ, 2014. http://ir.nmu.org.ua/handle/123456789/3692.

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У дисертації вирішене актуальне науково-технічне завдання підвищення ефективності прогнозу мілкоамплітудних геологічних порушень вугільних пластів методом неруйнівного контролю до 95%. Запропонована і обґрунтована математична модель розповсюдження акустичного хвильового пакету в дисперсійному породному середовищі, заснована на інформаційній амплітудно-фазовій модуляції несучих частот зондуючого сигналу. Розроблено ефективний спосіб прогнозу прихованих диз'юнктивів у вугільних пластах методом неруйнівного контролю. У його основу покладено аналіз особливостей прояву розривних геологічних порушень у функціях модуляційних параметрів сигналу, який отримано в результаті акустичного зондування вуглепородного масиву. Закономірності, отримані в результаті досліджень використані для розробки рекомендацій щодо тектонічної будови вугільних пластів для шахт «Дніпровська», «Краснолиманська» та «Степова».
В диссертации решена актуальная научно-техническая задача повышения эффективности прогноза малоамплитудных геологических нарушений угольных пластов методом неразрушающего контроля до 95%. Организованы и проведены комплексные шахтные, лабораторные и аналитические исследования распространения акустических колебаний в сложноструктурном породном массиве с геологическими нарушениями при использовании различных способов генерации зондирующего акустического сигнала. Впервые доказан факт информационной амплитудно-фазовой модуляции низкочастотных огибающих спектральной плотности мощности несущих частот зондирующего сигнала, прошедшего через исследуемый породный массив. Предложена и обоснована математическая модель распространения акустического волнового пакета в диспергирующей породной среде, отличающаяся от известных тем, что основана она на информационной амплитудно-фазовой модуляции несущих частот зондирующего сигнала. Предложена методика обработки сигнала волнового пакета зондирующего сигнала, прошедшего сквозь структурно-неоднородный породный массив, отличающаяся от известных тем, что в ее основу заложена фазовая демодуляция функции спектральной плотности мощности с применением метода низкочастотного эквивалента. Методика позволяет определить геометрические параметры неоднородностей при прохождении выработок в зонах геологических нарушений. Установлено, что исследование низкочастотной огибающей спектральной плотности мощности несущих частот и последующая ее фазовая демодуляция в среде Matlab позволяет получить фазовые характеристики огибающей, которые несут в себе информационную составляющую, отвечающую за структуру угольного пласта. Доказано, что в случае наличия нарушения график фазовой характеристики имеет один глобальный экстремум, который существенно отличается от остальных – локальных – своей первой производной. Причем, при фазовой демодуляции максимальная амплитуда несущей частоты иногда бывает менее информативна, чем боковые, поэтому в программе оценки нижних частот расчет функции полной фазы низкочастотных спектральных составляющих, осуществляется по четырем несущим с максимальной амплитудой, а среди них выбирается одна – с наиболее резким изменением сигнала. На основе их анализа сделан вывод о том, что на изгибе функции отражается излом характеристики. Доказано, что точка глобального экстремума фазовой характеристики низкочастотной огибающей спектральной плотности мощности несущих частот, вычисляемая методом низкочастотного эквивалента, определяет местонахождение разрывного геологического нарушения в угольном пласте с надежностью не менее 0.95, что позволяет существенно повысить надежность прогноза геоакустическим методом. Описанная точка экстремума возникает в определенное время распространения искусственного сигнала. Имея данные о местонахождении источника сигнала в момент времени его прохождения сквозь массив, местонахождении приемника и скорость распространения акустической волны в волноводе можно определить координаты соответствующей точки разрывного нарушения. Основываясь на анализе данного экстремума установлено, что координаты разрывного нарушения на прямой от источника искусственно генерируемого сигнала до приемника в плоскости волновода определяются произведением средней скорости распространения акустического колебания в угольном пласте и временем, соответствующем возникновению глобального экстремума фазовой характеристики низкочастотной огибающей спектральной плотности мощности несущих частот, что позволяет определить геометрические параметры разрывного нарушения в угольном пласте. Разработан эффективный способ прогноза скрытых дизьюнктивов в угольных пластах методом неразрушающего контроля. В его основу положен анализ особенностей проявления разрывных геологических нарушений в функциях модуляционных параметров сигнала, который получен в результате акустического зондирования углепородного массива. Закономерности, полученные в результате исследований использованы для разработки рекомендаций относительно тектонического строения угольных пластов для шахт «Краснолиманская» ГП «УК «Краснолиманская», «Днепровская» и «Степная» ПАО «ДТЭК Павлоградуголль».
In the thesis, the actual scientific and technical problem of raising efficiency of low-amplitude geological disturbances forecast in coal layers by the method of nondestructive testing up to 95 % is solved. The comprehensive mine, laboratory and analytical research concerning propagation of acoustic oscillations in the complex structured rock massif with geological faults by using different methods of probing acoustic signal generation are organized and conducted. The mathematical model of spreading acoustic wave packet in the dispersion medium based on the information and amplitude-phase modulation of carrying frequencies of the probing signal is proposed and justified. An effective method of the forecasting hidden disjunctives in coal layers by the method of non-destructive testing is developed. The method is based on the analysis of characteristic emergencies of geological faults in the functions of a signal modulation parameters obtained by acoustic probing of coal-rock massif. The regularities obtained from the research results are used to develop recommendations regarding the tectonic structure of coal layers for mines "Dniprovska", "Krasnolymanska" and "Stepova".

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Лисенко, Юлія Юріївна. "Інформаційно–діагностична система імпульсного вихрострумового неруйнівного контролю виробів машинобудування." Doctoral thesis, Київ, 2017. https://ela.kpi.ua/handle/123456789/21603.

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Дисертація присвячена розробці інформаційно – діагностичної системи імпульсного вихрострумового неруйнівного контролю виробів машинобудування. В роботі проаналізовано процеси в ланцюгах вихрострумового перетворювача в умовах імпульсному режиму збудження та визначено умови виникнення загасаючих гармонічних коливань, що дозволило в якості інформативних параметрів сигналів вихрострумового перетворювача запропонувати використання їх власної частоти та коефіцієнта загасання. В роботі розроблено методику обробки та аналізу інформативних параметрів сигналів вихрострумового перетворювача в імпульсному режимі збудження, в основі якої лежить визначення запропонованих інформативних параметрів цих сигналів через їх амплітудну та фазову характеристики за допомогою застосування перетворення Гільберта. Запропоновано використання експоненційної апроксимації для амплітудної характеристики та лінійного тренду для фазової характеристики сигналу вихрострумового перетворювача для підвищення точності визначення інформативних параметрів цього сигналу. Проведено аналіз похибок визначення частоти власних коливань та коефіцієнта загасання сигналу вихрострумового перетворювача, який дозволив визначити умови отримання мінімальної похибки визначення цих інформативних параметрів сигналу та визначити оптимальний час аналізу, що суттєво впливає на результати контролю в умовах впливу завад і шумів.

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Wang, Ching-Shun, and 王敬舜. "Frequency effect on electro-optical characteristics of amorphous blue phase liquid crystal." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/19032193689249486116.

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碩士
國立中興大學
奈米科學研究所
105
Here, room-temperature liquid-crystal BPIII can be obtained by adding chiral dopant only. The temperature range of BPIII can be wider than 25 K. Observation on the electro-optical characteristic of IPS-BPIII was done by controlling the strength and frequency of the external electric field. The experimental results showed that the light transmittance gradually decreases as increasing the frequency of electric field. However, that is not caused by the dielectric dispersion after confirming the frequency dependence dielectric constants of LC. Moreover, the field-dependence induced birefringence was calculated from the polarimetric measurement. When the square of the electric field was less than 100 V2/μm2 , the electric field induced birefringence can be explained by model of Kerr effect. However, when the square of the electric field was greater than 100 V2/μm2, the electric-field induced birefringence might be explained by Pockels effect or other electric-optical effect.

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Books on the topic "Phase-frequency characteristic"

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Maggiore, Michele. Stochastic backgrounds of cosmological origin. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198570899.003.0013.

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Characteristic frequency of relic GWs. Production mechanisms of GWs in the early universe: preheating, phase transitions, cosmic strings, alternatives to inflation. Bounds on primordial GW backgrounds: nucleosynthesis bound, bounds from CMB, observational limits at interferometers.

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Araújo, Ana Cláudia Vaz de. Síntese de nanopartículas de óxido de ferro e nanocompósitos com polianilina. Brazil Publishing, 2021. http://dx.doi.org/10.31012/978-65-5861-120-2.

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In this work magnetic Fe3O4 nanoparticles were synthesized through the precipitation method from an aqueous ferrous sulfate solution under ultrasound. A 23 factorial design in duplicate was carried out to determine the best synthesis conditions and to obtain the smallest crystallite sizes. Selected conditions were ultrasound frequency of 593 kHz for 40 min in 1.0 mol L-1 NaOH medium. Average crystallite sizes were of the order of 25 nm. The phase obtained was identified by X-ray diffractometry (XRD) as magnetite. Scanning electron microscopy (SEM) showed polydisperse particles with dimensions around 57 nm, while transmission electron microscopy (TEM) revealed average particle diameters around 29 nm, in the same order of magnitude of the crystallite size determined with Scherrer’s equation. These magnetic nanoparticles were used to obtain nanocomposites with polyaniline (PAni). The material was prepared under exposure to ultraviolet light (UV) or under heating, from dispersions of the nanoparticles in an acidic solution of aniline. Unlike other synthetic routes reported elsewhere, this new route does not utilize any additional oxidizing agent. XRD analysis showed the appearance of a second crystalline phase in all the PAni-Fe3O4 composites, which was indexed as goethite. Furthermore, the crystallite size decreases nearly 50 % with the increase in the synthesis time. This size decrease suggests that the nanoparticles are consumed during the synthesis. Thermogravimetric analysis showed that the amount of polyaniline increases with synthesis time. The nanocomposite electric conductivity was around 10-5 S cm-1, nearly one order of magnitude higher than for pure magnetite. Conductivity varied with the amount of PAni in the system, suggesting that the electric properties of the nanocomposites can be tuned according to their composition. Under an external magnetic field the nanocomposites showed hysteresis behavior at room temperature, characteristic of ferromagnetic materials. Saturation magnetization (MS) for pure magnetite was ~ 74 emu g-1. For the PAni-Fe3O4 nanocomposites, MS ranged from ~ 2 to 70 emu g-1, depending on the synthesis conditions. This suggests that composition can also be used to control the magnetic properties of the material.

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Wendling, Fabrice, Marco Congendo, and Fernando H. Lopes da Silva. EEG Analysis. Edited by Donald L. Schomer and Fernando H. Lopes da Silva. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780190228484.003.0044.

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This chapter addresses the analysis and quantification of electroencephalographic (EEG) and magnetoencephalographic (MEG) signals. Topics include characteristics of these signals and practical issues such as sampling, filtering, and artifact rejection. Basic concepts of analysis in time and frequency domains are presented, with attention to non-stationary signals focusing on time-frequency signal decomposition, analytic signal and Hilbert transform, wavelet transform, matching pursuit, blind source separation and independent component analysis, canonical correlation analysis, and empirical model decomposition. The behavior of these methods in denoising EEG signals is illustrated. Concepts of functional and effective connectivity are developed with emphasis on methods to estimate causality and phase and time delays using linear and nonlinear methods. Attention is given to Granger causality and methods inspired by this concept. A concrete example is provided to show how information processing methods can be combined in the detection and classification of transient events in EEG/MEG signals.

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Book chapters on the topic "Phase-frequency characteristic"

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Weik, Martin H. "phase-frequency characteristic." In Computer Science and Communications Dictionary, 1259. Boston, MA: Springer US, 2000. http://dx.doi.org/10.1007/1-4020-0613-6_13907.

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Weik, Martin H. "phase-versus-frequency characteristic." In Computer Science and Communications Dictionary, 1263. Boston, MA: Springer US, 2000. http://dx.doi.org/10.1007/1-4020-0613-6_13944.

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Chen, Peng, Zixuan Xu, Yang Cao, Xiaofeng Gu, Zhen Zhong, and Lei He. "A Simple Method for Studying LED Phase–Frequency Characteristics." In Lecture Notes in Electrical Engineering, 1697–704. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4614-4981-2_186.

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Boguslawsky, Iliya, Nikolay Korovkin, and Masashi Hayakawa. "Method of Determination Stator Winding MMF at Arbitrary Phase Current Waveform and Unequal Width of Phase Zones (for Investigation of Operational Characteristics of Frequency: Controlled Motors)." In Large A.C. Machines, 411–32. Tokyo: Springer Japan, 2016. http://dx.doi.org/10.1007/978-4-431-56475-1_21.

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Rose, Wade R., S. I. Rokhlin, Peter B. Nagy, and Laszlo Adler. "Polar Characteristics of the Group and Phase Velocities as Well as the Frequency Dependence of Lamb Waves in Graphite/Epoxy Composites." In Nondestructive Characterization of Materials II, 61–68. Boston, MA: Springer US, 1987. http://dx.doi.org/10.1007/978-1-4684-5338-6_6.

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Nikookar, Homayoun. "Waveform Design for Energy Efficient OFDM Transmission." In Energy Efficiency [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.100564.

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In this chapter, a green radio transmission using the binary phase-shift keying (BPSK) modulated orthogonal frequency-division multiplexing (OFDM) signal is addressed. First, the OFDM transmission signal is clearly stated. For a specified performance of the system, the least transmit power occurs by the optimal OFDM shape, which is designed to minimize the average inter-carrier interference power taking into account the characteristic of the transmit antenna and the detection process at the receiver. The optimal waveform is obtained by applying the calculus of variations, which leads to a set of differential equations (known as Euler equations) with constraint and boundary conditions. Results show the transmission effectiveness of the proposed technique in the shaping of the signal, as well as its potential to be further applied to smart context-aware green wireless communications.

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Milic, Ljiljana. "Lth-Band Digital Filters." In Multirate Filtering for Digital Signal Processing, 206–41. IGI Global, 2009. http://dx.doi.org/10.4018/978-1-60566-178-0.ch007.

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Digital Lth-band FIR and IIR filters are the special classes of digital filters, which are of particular interest both in single-rate and multirate signal processing. The common characteristic of Lth-band lowpass filters is that the 6 dB (or 3 dB) cutoff angular frequency is located at p/L, and the transition band is approximately symmetric around this frequency. In time domain, the impulse response of an Lth-band digital filter has zero valued samples at the multiples of L samples counted away from the central sample to the right and left directions. Actually, an Lth-band filter has the zero crossings at the regular distance of L samples thus satisfying the so-called zero intersymbol interference property. Sometimes the Lthband filters are called the Nyquist filters. The important benefit in applying Lth band FIR and IIR filters is the efficient implementation, particularly in the case L = 2 when every second coefficient in the transfer function is zero valued. Due to the zero intersymbol interference property, the Lth-band filters are very important for digital communication transmission systems. Another application is the construction of Hilbert transformers, which are used to generate the analytical signals. The Lth-band filters are also used as prototypes in constructing critically sampled multichannel filter banks. They are very popular in the sampling rate alteration systems as well, where they are used as decimation and interpolation filters in single-stage and multistage systems. This chapter starts with the linear-phase Lth-band FIR filters. We introduce the main definitions and present by means of examples the efficient polyphase implementation of the Lth-band FIR filters. We discuss the properties of the separable (factorizable) linear-phase FIR filter transfer function, and construct the minimum-phase and the maximum-phase FIR transfer functions. In sequel, we present the design and efficient implementation of the halfband FIR filters (L = 2). The class of IIR Lth-band and halfband filters is presented next. Particular attention is addressed to the design and implementation of IIR halfband filters. Chapter concludes with several MATLAB exercises for self study.

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Gautam, Usha, and Tarun Kumar Rawat. "Analysis of Wideband Second-Order Microwave Integrators." In Innovations in Ultra-Wideband Technologies. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.94843.

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This chapter presents the implementation of stable, accurate, and wideband second-order microwave integrators (SOMIs). These SOMI designs are obtained by the use of various cascading combinations of transmission line sections and shunt stubs. In order to obtain the optimal values of the characteristic impedances of these line elements, the particle swarm optimization (PSO), cuckoo search algorithm (CSA) and gravitational search algorithm (GSA) are used to approximate the magnitude response of the ideal second-order integrator (SOI). Based on magnitude response, absolute magnitude error, phase response, convergence rate, pole-zero plot, and improvement graph, the performance measure criteria for the proposed SOMIs are performed. The results of the simulation and statistical analysis reveal that GSA exceeds the PSO and CSA in order to approximate the ideal SOI in all state-of-the-art eligible for wide-band microwave integrator. The designed SOMI is compact and suitable for applications covering ultra-wideband (UWB). The designed SOMI structure is also simulated on Advanced Design Software (ADS) in the form of a microstrip line on a dielectric constant 2.2 RT/Duroid substrate with a height of 0.762 mm. In the 3–15 GHz frequency range, the simulated magnitude result agrees well with the ideal one.

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Graf, William L. "Fluvial Sediment, Forms, and Processes." In Plutonium and the Rio Grande. Oxford University Press, 1995. http://dx.doi.org/10.1093/oso/9780195089332.003.0009.

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Although there are numerous aspects of sediment that might be considered in conjunction with questions related to plutonium transport and storage in rivers, particle size is the critical characteristic. Information on the size distribution of particles in sedimentary deposits connects plutonium, sediment, and river processes. An explanation of the geography of plutonium in the regional river system requires knowledge of particle sizes, the distribution of those particle sizes, and their potential mobility in the regional canyons, rivers, and reservoirs. Some general data concerning the size characteristics of fluvial sediment in the Rio Grande system are available from published sources for a few locations, particularly Los Alamos Canyon. Recent, previously unpublished field and laboratory investigations provide additional detailed information for the changing sedimentary environments associated with the river system. This chapter reviews the characteristics of river sediments in the Northern Rio Grande and presents a regional sediment budget from historical and geographical perspectives. Almost 200 sediment samples from deposits of various ages near the channels of the Rio Grande and tributaries demonstrate the variability of the sediment particle sizes. The analysis had three parts: sample collection, sieving, and electronic particle analysis. In the sample-collection phase, collection sites represented identifiable sedimentary units or channel deposits. Each collection site yielded three samples to indicate local variability. Penetration of the surfaces to depths of 5 to 90 cm with a standard cylindrical soil probe provided masses of about 120 g each for laboratory analysis. Investigators kept only the split of the sample that included those particles with diameters of less than 2 mm (that is, sand size or smaller). Laboratory procedures included sieving and electronic counting. Sieving divided each sample into masses consisting of those particles larger than 63 microns in diameter (the sand fraction) and those smaller than 63 microns (the silt and clay fraction). The weight of each fraction provided a standarized means of comparing the samples for this study and the results reported by other researchers. Analysis of the silt and clay fraction using a Coulter electronic particle analysis system permitted a detailed investigation of the frequency distribution of the particles in this restricted range.

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Pereira, Pedro, Fábio Passos, and M. Helena Fino. "Optimization-Based Design of RF-VCOs with Tapered Inductors." In Advances in Computer and Electrical Engineering, 134–57. IGI Global, 2015. http://dx.doi.org/10.4018/978-1-4666-6627-6.ch006.

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Voltage-Controlled Oscillators (VCOs) are widely used in wireless transceivers. Due to the stringent specifications regarding phase-noise, LC-VCOs are usually adopted. The need for maximizing phase-noise as well as minimizing the power consumption makes imperious the adoption of optimization-based design methodologies. For the optimization of the LC-VCO characteristics, special attention must be paid to the integrated inductor design, since its quality factor may have a strong influence in the LC-VCO phase-noise. Furthermore, designers must ensure that the higher limit of VCO operating frequency is sufficiently below the inductor resonant frequency. In this chapter, a study on the influence of the quality factor of the inductors on the LC-VCO overall behavior is presented. Then, optimization of integrated inductors by exploring the inductor geometric layout is presented. Finally, results obtained for the design of an LC-VCO in 130nm Technology using a previously optimized inductor are presented.

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Conference papers on the topic "Phase-frequency characteristic"

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Hongmei Ma, Peng Li, and Weining Xue. "Optimization design of passive filter's phase-frequency characteristic." In 2009 IEEE International Conference on Communications Technology and Applications (ICCTA). IEEE, 2009. http://dx.doi.org/10.1109/iccomta.2009.5349101.

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Wang, Fuliang, Changhui Zou, and Jiaping Qiao. "Dynamic phase-frequency characteristic of thermosonic wire bonder transducer." In 2008 International Conference on Electronic Packaging Technology & High Density Packaging (ICEPT-HDP). IEEE, 2008. http://dx.doi.org/10.1109/icept.2008.4607106.

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"HIGH-FREQUENCY ANALYSIS OF PHASE-LOCKED LOOP AND PHASE DETECTOR CHARACTERISTIC COMPUTATION." In 8th International Conference on Informatics in Control, Automation and Robotics. SciTePress - Science and and Technology Publications, 2011. http://dx.doi.org/10.5220/0003522502720278.

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Ryasnyi, Yu V., and E. V. Dezhina. "Design method for digital recursive filter with linear phase-frequency characteristic." In 2012 IEEE 11th International Conference on Actual Problems of Electronics Instrument Engineering (APEIE). IEEE, 2012. http://dx.doi.org/10.1109/apeie.2012.6628963.

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Hou, Tianrui, Guodong Xu, Pengfei Li, and Jialin Hou. "Pulsar Signal Characteristic Frequency Identification And Phase Estimation Base On FFT." In International Conference on Logistics Engineering, Management and Computer Science (LEMCS 2014). Paris, France: Atlantis Press, 2014. http://dx.doi.org/10.2991/lemcs-14.2014.146.

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Dong, Shaofeng, Wei Zhou, Jinsong Zhan, and Wei Hu. "Phase group characteristic based frequency measurement method with wide band and fast response." In 2013 Joint European Frequency and Time Forum & International Frequency Control Symposium (EFTF/IFC). IEEE, 2013. http://dx.doi.org/10.1109/eftf-ifc.2013.6702111.

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Huang, S. F., and X. G. Wang. "A protection scheme for phase-to-phase faults based on spectrum characteristic of fault-generated high-frequency transient signals." In Energy Society General Meeting (PES). IEEE, 2009. http://dx.doi.org/10.1109/pes.2009.5275917.

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Zhang, Shuai, Houlei Gao, Mengqian Hou, Yong Sun, Zhimin Shao, and Jianxiu Li. "Frequency spectrum characteristic analysis of single-phase ground fault in a Petersen-coil grounded system." In 2015 5th International Conference on Electric Utility Deregulation and Restructuring and Power Technologies (DRPT). IEEE, 2015. http://dx.doi.org/10.1109/drpt.2015.7432259.

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Wu, Xiangqiang, Tong Huang, Xin Chen, Haibing Hu, and Guoqing He. "Frequency Characteristic and Impedance Analysis on Three-Phase Grid-Connected Inverters Based on DDSRF-PLL." In 2019 10th International Conference on Power Electronics and ECCE Asia (ICPE 2019 - ECCE Asia). IEEE, 2019. http://dx.doi.org/10.23919/icpe2019-ecceasia42246.2019.8797289.

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Xie, Zhiwei, Yandong Chen, Wenhua Wu, Yuancan Xu, Shang Peng, Jinming Liu, and Shixiang Cao. "Broadband Impedance Modeling and its Characteristic Analysis of Single-phase Grid-connected Inverter Considering Frequency Coupling." In 2019 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC). IEEE, 2019. http://dx.doi.org/10.1109/appeec45492.2019.8994642.

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Reports on the topic "Phase-frequency characteristic"

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Allen, A., S. Santoso, and E. Muljadi. Algorithm for Screening Phasor Measurement Unit Data for Power System Events and Categories and Common Characteristics for Events Seen in Phasor Measurement Unit Relative Phase-Angle Differences and Frequency Signals. Office of Scientific and Technical Information (OSTI), August 2013. http://dx.doi.org/10.2172/1096101.

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