Дисертації з теми "Signals attenuation"
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Smith, Patrick John. "Attenuation of volcanic seismic signals." Thesis, University of Leeds, 2010. http://etheses.whiterose.ac.uk/1131/.
Повний текст джерелаJohnston, Jerry W., and Steve LaPoint. "ROCKET MOTOR PLUME EFFECTS ON TM SIGNALS - MODEL CORROBORATION." International Foundation for Telemetering, 1996. http://hdl.handle.net/10150/607592.
Повний текст джерелаThis paper presents the interim results of an effort to corroborate analytic model predictions of the effects of rocket motor plume on telemetry signal RF propagation. When space is available, telemetry receiving stations are purposely positioned to be outside the region of a rocket motor's plume interaction with the RF path; therefore, little historical data has been available to corroborate model predictions for specific rocket motor types and altitudes. RF signal strength data was collected during the flight of HERA target missile by White Sands Missile Range (WSMR) using a transportable telemetry receiving site specifically positioned to be within the rocket plume region of influence at intermediate altitudes. The collected data was analyzed and compared to an RF plume attenuation model developed for pre-mission predictions. This work was directed by the US Army Kwajalein Atoll (USAKA)/ Kwajalein Missile Range (KMR) Safety Division.
Doh, Yann. "Nouveaux modèles d'estimation monophone de distance et d'analyse parcimonieuse : Applications sur signaux transitoires et stationnaires bioacoustiques à l’échelle." Thesis, Toulon, 2014. http://www.theses.fr/2014TOUL0020/document.
Повний текст джерелаAcoustic waves show low dispersion due to the underwater propagation, compared to the propagation in the air. Some species of cetaceans communicate at long distance, others use their sound production for orientation. The goal of the scientic area called bioacoustics is to study animal species based on the analysis of their emitted sound. Their sounds can be used to detect, to classify and to locate the cetaceans. Recordings can be done with an passive acoustic array of multiple hydrophones, but this method is expensive and difficult to deploy. Thus, in order to scale this approach, we propose in this Phd thesis several original single hydrophone models to analyze these stationary or transient signals.Firstly, we provide a new theoretical model to estimate the distance between the impulsive source (ex. biosonar of the cetacean) and the hydrophone. Our model, the Intra Spectral ATtenuation (ISAT), is based on the spectral signal alteration due to the underwater acoustic propagation, especially the differences in different frequency bands. We also approximated ISAT by an artificial neural network. Both models are validated on clicks emitted by sperm whales (Physeter macrocephalus) recorded by our sonobuoy BOMBYX and our data-acquisition system DECAV developed incollaboration with the National Park of Port-Cros (France) and the Pelagos sanctuary for the protection of marine mammals in the Mediterranean sea (France). The error (RMSE) measures on the recordings of the NATO test center in the Bahamas are about500 meters, promising further real applications. Secondly, we worked on the variations of the cetacean vocalizations using the sparse coding method. The encoding of thecepstrums by unsupervised learning of a dictionary shows bigrammic time changes of the songs of humpback whales (Megaptera novaeangliae). We validate this model on signals recorded in the Ste Marie Channel (Madagascar) between 2008 and 2014, through our network of hydrophones BAOBAB which is the first passive acoustic array deployed in the Indian Ocean.Our models are part of the Saled Bioacoustics project (SABIOD, MI CNRS) and open perspectives for temporal and spatial scaling of bioacoustics
Maenou, Takatoshi, and Masaaki Katayama. "Study on Signal Attenuation Characteristics in Power Line Communications." IEEE, 2006. http://hdl.handle.net/2237/7798.
Повний текст джерелаDe, Villiers Wernich. "Prediction and measurement of power line carrier signal attenuation and fluctuation." Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52410.
Повний текст джерелаENGLISH ABSTRACT: A frequency domain Power Line Carrier (PLC) simulation program, with the ability to simulate signal attenuation including the coupling equipment, was developed. This simulation program was put to the test against the independent program of Professor L.M. Wedepohl and against practical field measurements. The predictions of the two programs were in precise agreement for a wide range of input parameters. Results from the field tests and predictions also showed close agreement. Further investigations, applying the simulation program, explained how ground conductors and soil resistivity influences PLC signal propagation. An experiment, which was developed to monitor PLC signal attenuation, was installed on the PLC system between Koeberg power station and Acacia substation, both near Cape Town. Data logged continuously over 28 days, indicated measurable and deterministic PLC signal attenuation variations with typical time constants of a few hours. Simulations of the PLC system indicated that the signal amplitude variations were influenced by changes in the height above the ground plane of the phase conductor. This significant finding creates the possibility to obtain real time knowledge of the sag of an Over Head Transmission Line (OHTL) by exploiting an operational PLC system. The knowledge about real time sag can be used in economical dynamic ampacity control systems. The practical and financial benefits to the electricity supply and distribution industry can be significant.
AFRIKAANSE OPSOMMING: 'n Frekwensie gebied "Power Line Carrier" (PLC) simulasie program wat die sein verswakking en die koppeling verliese kan naboots, is ontwikkel. Die program is getoets teen die onafhanklike program van Professor L.M. Wedepohl asook praktiese metings in die veld. Die vooruitskatings van beide programme is presies die selfde vir 'n wye reeks van parameters. Metings en nabootsings het ook noue ooreenstemming getoon. Verdere ondersoek, m. b. v. die program, is gedoen ten einde te verduidelik hoe grond-geleiers en grond weerstand die PLC sein se voortplanting beïnvloed. 'n Eksperiment om die PLC sein se verswakking mee te monitor is ontwerp. Die eksperiment was geïnstalleer in die PLC stelsel tussen Koeberg kernkragstasie en Acacia substasie, naby Kaapstad. Die eksperiment was vir 28 dae geaktiveer en die data wat die eksperiment opgelewer het toon meetbare PLC sein verswakking met tyd konstantes van 'n paar uur. Verdere nabootsings het gewys dat die veranderende verswakking in die PLC seinsterkte toegeskryf kan word aan die wisseling in hoogte van die fase geleiers bo die grondvlak. Hierdie bevinding is van besondere belang aangesien dit die moontlikheid oopmaak om die gemiddelde sak van kraglyne in reële tyd en onder bedryfs toestande te kan meet. Die informasie van die reële sak van kraglyne kan gebruik word in effektiewe stroomdrae-vermoë beheer stelsels. Die praktiese en finansiële voordele wat krag voorsieners en verspreiders hieruit kan put kan aansienlik wees.
Pokorný, Rostislav. "Návrh programovatelného útlumového členu." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2020. http://www.nusl.cz/ntk/nusl-413091.
Повний текст джерелаViklund, Johan. "Atmospheric Attenuation for Lidar Systems in Adverse Weather Conditions." Thesis, Umeå universitet, Institutionen för fysik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-184706.
Повний текст джерелаWhite, John D. H. "A random signal ultrasonic test system for highly attenuating media." Thesis, Keele University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315234.
Повний текст джерелаPollard, Kimberley Jeanne. "Study of slant path attenuation ratios derived from a dual-polarized radar." Thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-03122009-040448/.
Повний текст джерелаSalchak, Iana. "Ingested Wireless Capsule Localisation Based on In-body RF Attenuation Path Loss." Thesis, Griffith University, 2022. http://hdl.handle.net/10072/417699.
Повний текст джерелаThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Eng & Built Env
Science, Environment, Engineering and Technology
Full Text
Zohidov, Bahtiyor. "Retrieval of rainfall fields using signal attenuation measurements from commercial microwave links. A modeling feasibility study." Thesis, Ecole centrale de Nantes, 2016. http://www.theses.fr/2016ECDN0022.
Повний текст джерелаThe objective in this study is to assess the feasibility of retrieval of rainfa ll fields in urban areas using commercial microwave links, with a special focus given on cellular network, in a simulation framework applied to a realistic case study. The study domain is the city of Nantes, France. As a basis, we use a data set consisting of 207 weather radar images recorded by Météo - France C band at high spatial (250m x 250m) and temporal (5 min) resolutions. We generated rain attenuation data along those links that are used to represent real signal attenuation data that can be recorded a t microwave antenna stations. Two retrieval algorithms, namely inverse and tomography, are proposed to retrieve rainfall fields based on the generated rain attenuation data. To validate the system performance, we carry out series of rain retrieval tests in light rain, shower, organized and unorganized storm events with high spatial and temporal variability. The comparisons between the inverse and the tomographic algorithms are also made over 40 rainfall fields in 4 events in order to define limitations and capabilities of both algorithms
Сальников, Д. С., А. И. Цопа, В. В. Павликов, А. Д. Собколов, and Н. В. Руженцев. "Millimeter-Range Radiometric System for Perspective Problems of Meteorology and Telecommunication." Thesis, Kyiv: Ukraine, 2017. http://openarchive.nure.ua/handle/document/5696.
Повний текст джерелаPrakash, Sunjeev. "Experimental analysis of artificial signal type and performance feedback delivery schedule in attenuating vigilance decrement." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ56718.pdf.
Повний текст джерелаVenator, Kurt Richard. "The Influence of signal attenuation and degradation on behavior and midbrain auditory thresholds in the cricket frog, Acris crepitans blanchardi /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
Повний текст джерелаYamamoto, Kanjo. "Attenuation of virus-induced myocardial injury by inhibition of the AT1R signal and decreased NF-κB activation in knock-out mice". Kyoto University, 2004. http://hdl.handle.net/2433/147503.
Повний текст джерелаBittermann, Lennart Martin [Verfasser], Claus-Christian [Akademischer Betreuer] Glüer, and Ulf [Gutachter] Lützen. "Light Signal Attenuation by Murine Cortical Bone for Quantification of Fluorescence Reflectance Imaging / Lennart Martin Bittermann ; Gutachter: Ulf Lützen ; Betreuer: Claus-Christian Glüer." Kiel : Universitätsbibliothek Kiel, 2019. http://d-nb.info/1225349265/34.
Повний текст джерелаKosmák, Václav. "Analýza stávajícího kluzného kontaktu, kvalitativních a funkčních vlastností "kroužkostrojů"." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-318099.
Повний текст джерелаPelteku, Altin E. "Adaptive Suppression of Interfering Signals in Communication Systems." Digital WPI, 2013. https://digitalcommons.wpi.edu/etd-dissertations/138.
Повний текст джерелаLaugier, Pascal. "Estimation in vivo de l'attenuation des ultrasons dans les tissus biologiques par analyse temps-frequence du signal echographique." Paris 7, 1987. http://www.theses.fr/1987PA077127.
Повний текст джерелаLeandro, Carolina Gonçalves. "Aplicação da análise do sinal do GPR na definição de ambientes costeiros." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2018. http://hdl.handle.net/10183/173817.
Повний текст джерелаIn the Pinheira regressive barrier, four coastal depositional environments are recognized, characterized by geological parameters such as lithofacies analysis, sedimentary structures, compaction degree and set of mollusks. Information that is analyzed together with images of geophysical data obtained with the Ground Penetrating Radar (GPR) method to determine these environments. The present work aims to characterize these depositional environments by analyzing the signal amplitude in traces with central frequencies antennas of 80, 100, 200 and 400 MHz in conjunction with the compaction and lithological data of a drill hole. It also shows the behavior of signal attenuation in relation to the humidity present in the environment. The analysis of the traces allowed the identification of the contacts between the environments already described for regressive barriers, showing variation in the value of the amplitudes (decrease or increase), together with the variation in the degree of compaction, which evidences in subsurface the change between the environments of foredune ridges, backshore/foreshore and upper and lower shoreface. The interference of humidity in attenuation of the signal in the studied data can be observed only in the first 0.5 m. Rainfall was not relevant for signal attenuation in the studied sandy deposits with water level close to the surface. The analysis of the radargrams for all the antennas allowed the identification of the patterns of reflectors already described for the environments of the study area and the central frequency antenna of 200 MHz showed the highest resolution for the definition of all the environments.
Han, Chao. "Advanced signal and imaging methods in ultrasound cortical bone assessment." Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS144.
Повний текст джерелаUltrasound technology provides an affordable means to implement non-invasive solutions to diagnostically assess the mechanical characteristics of the bone. In this thesis we introduce Orthogonal Matching Pursuit (OMP) to obtain a robust reconstruction of the waveform of each echo bouncing off the cortical bone surfaces. Echoes' time-of-flight and central frequencies are used to calculate Ct.Th and normalized broadband attenuation (nBUA). In vivo measurements have been successfully performed with pulse-echo ultrasound and reference data wase obtained with HR-pQCT (cortical thickness, vBMD). Ct.Th and nBUA were highly correlated to reference thickness values (r2=0.90) and vBMD (r2=0,90), respectively. The second main contribution is that we introduce Time Domain Topological Energy (TDTE) method and migration into cortical bone imaging. TDTE shows well performance in extracting the structure of cortical bone, including the external, internal boundary of cortical bone and porous structure inside the cortical bone. Migration can provide a rough quantitative distribution of density, compression wave speed, and shear wave speed
Costa, Filho Carlos Alberto da 1988. "Applications of independent component analysis to the attenuation of multiple reflections in seismic data = Aplicações da análise de componentes independentes à atenuação de reflexões múltiplas em dados sísmicos." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/306138.
Повний текст джерелаDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matemática Estatística e Computação Cientifica
Made available in DSpace on 2018-08-22T06:13:33Z (GMT). No. of bitstreams: 1 CostaFilho_CarlosAlbertoda_M.pdf: 3131395 bytes, checksum: f8687abfc7e346fdd8e6dc40746526e8 (MD5) Previous issue date: 2013
Resumo: As reflexões de ondas sísmicas na subsuperfície terrestre podem ser colocadas em duas categorias disjuntas: reflexões primárias e múltiplas. Reflexões primárias carregam informações pontuais sobre um refletor específico, enquanto reflexões múltiplas carregam informações sobre interfaces e pontos de reflexão variados. Consequentemente é usual tentar atenuar reflexões múltiplas e trabalhar somente com reflexões primárias. Neste trabalho, a teoria de ondas acústicas é desenvolvida somente a partir da equação da onda. Um resultado que demonstra como a propagação de ondas acústicas pode ser descrita somente com uma única multiplicação por matriz é exposta. Este resultado permite que um algoritmo seja desenvolvido que, em teoria, pode ser usado para remover todas as reflexões múltiplas que refletiram na superfície pelo menos uma vez. Uma implementação prática deste algoritmo é mostrada. Por conseguinte, a teoria de análise de componentes independentes é apresentada. Suas considerações teóricas e práticas são abordadas. Finalmente, ela é usada em conjunção com o método de eliminação de múltiplas de superfície para atenuar múltiplas de quatro dados diferentes. Estes resultados são então analisados e a eficácia do método é avaliada
Abstract: The reflections of seismic waves in the subsurface of the Earth can be placed under two disjoint categories: primary and multiple reflections. Primary reflections carry pointwise information about a specific reflector while multiple reflections carry informations about various interfaces and reflection points. Consequently, it is customary to attempt to attenuate multiple reflections and work solely with primary reflections. In this work, the theory of acoustic waves is developed solely from the wave equation. A result that shows how acoustic wave propagation can be described as a single matrix multiplication is exposed. This result enables one to develop an algorithm that, in theory, can be used to remove all multiple reflections that have reflected on the surface at least once. The practical implementation of this algorithm is shown. Thereafter, the theory of independent component analysis is presented. Its theoretical and practical considerations are addressed. Finally, it is used in conjunction with the surface-related multiple elimination method to attenuate multiples in four different datasets. These results are then analyzed and the efficacy of the method is evaluated
Mestrado
Matematica Aplicada
Mestre em Matemática Aplicada
Oschlisniok, Janusz [Verfasser], Martin [Gutachter] Pätzold, and Andreas [Gutachter] Eckart. "Transport of sulfuric acid in the atmosphere of Venus studied on the basis of radio signal attenuation effects observed in the Venus Express Radio Science Experiment VeRa / Janusz Oschlisniok ; Gutachter: Martin Pätzold, Andreas Eckart." Köln : Universitäts- und Stadtbibliothek Köln, 2020. http://d-nb.info/122171841X/34.
Повний текст джерелаAntoniadis, Antonios. "Moisture calibration of an R.F based inline moisture sensor : An inline moisture sensor based on radio wave attenuation, Microtec M3 Scan, was calibrated to maximise correlation between real water content in wood and received signal." Thesis, Luleå tekniska universitet, Träteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-77359.
Повний текст джерелаSasso, Magali. "Traitement et analyse du signal ultrasonore pour la caractérisation de l'os cortical." Phd thesis, Université Paris-Est, 2008. http://tel.archives-ouvertes.fr/tel-00345631.
Повний текст джерелаAlali, Khaled Ahmed. "Azimuthal Localization and Detection of Vehicular Backup Alarms Under Electronic and Non-Electronic Hearing Protection Devices in Noisy and Quiet Environments." Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/26890.
Повний текст джерелаPh. D.
Ikonen, Linus, and Daniel Nilsson. "Quality assessment of mineral wool insulation plates : Using ultrasonic non-destructive testing." Thesis, Blekinge Tekniska Högskola, Institutionen för maskinteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-18223.
Повний текст джерелаI tillverkningsprocessen av isolerskivor i stenull uppstår inneboende defekter i isolerskivorna, dessa defekter består av osmälta basmineraler och ohärdat bindemedel. För att kunna sortera bort dessa skadade skivor från tillverkningslinjen behövs en pålitlig metod för kvalitetsbedömning. Avsikten med det här arbetet är att hitta en oförstörande provningsmetod baserad på ultraljud som kan identifiera de inneboende defekterna. Detta genomfördes genom experiment på defekta isolerskivor med tre olika oförstörande provningsmetoder baserade på ultraljud. Dessa metoderna var, higher harmonics, pitch-echo och through transmission. Through transmission visade lovande resultat i att identifiera de båda typerna av skador. Metoden är baserad på att en sändare sänder ut ultraljud till en mottagare placerad i linje med sändaren. När ett defekt område passerar ultraljudsvågen mellan sändaren och mottagaren försvagas intensiteten av signalen. Försvagningen av signalen beror mestadels på att densiteten är högre hos defekterna än hos basmaterialet i isolerskivan. Denna försvagning indikerar att en defekt befinner sig i mätområdet. Metoden är väl implementerbar i en tillverkningslinje, då det är en snabb metod vilket den behöver vara då objektet är i rörelse. Mer mätningar behövs för att fastställa ett pålitligt referensvärde för att konsekvent kunna sortera ut de defekta isolerskivorna. Metoden är endast utvärderad i en småskalig laborationsmiljö och det behövs fler tester i en större skala undersöka pålitligheten i det verkliga scenariot med tillverkningslinjen.
Bárta, Miroslav. "Vliv atmosférických turbulencí na optický svazek." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-218156.
Повний текст джерелаAli, M'zé Wahabi. "Évaluation non destructive de la contamination du béton par les chlorures avec la technique radar." Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30278/document.
Повний текст джерелаGround Penetrating Radar (GPR) is an usual nondestructive testing method for the assessment of concrete structures. The benefit of this method lies within its ability to assess quickly a large scale of concrete surface. Generally, GPR is used for the localization of reinforcements or for the thickness measurements. However, GPR can be also used for the diagnosis of concrete because concrete is a porous dielectric material which can modify the propagation of the electromagnetic (EM) waves. Most common results present the ability of GPR to assess moisture. But, GPR could be also used to detect the presence of chlorides into the interstitial concrete solution as chlorides can modify the concrete conductivity and altered the electromagnetic signal waves. However, only few studies have been carry-out on that field. Therefore, in this study, we propose to use GPR electromagnetic waves to evaluate both the water content and the chloride content inside the interstitial concrete solution of several tests concrete samples. So, several groups of concrete samples with the same formulation will be conditioned for different chloride contamination modes. Thereafter, a velocity measurement process will be proposed from the reflected signal wave analysis. In that process, we will show that the velocity is only affected by the water content while the attenuation strongly affected by both the water content and the chloride content. Furthermore, we will test several permittivity models to predict the dielectric permittivity and the loss factor estimated from the concrete samples measurements with the GPR device and the electrical resistivity device
Одарченко, Роман Сергійович, Roman Odarchenko та Одарченко Роман Сергеевич. "Методологія підвищення ефективності функціонування стільникових мереж зв'язку". Thesis, Національний авіаційний університет, 2019. http://er.nau.edu.ua/handle/NAU/38385.
Повний текст джерелаДиссертация посвящена вопросам разработки методологии повышения эфективности сотовых сетей связи. В работе был проведен анализ качества обслуживания абонентов сотовых сетей в Украине с целью определения их эффективности. Было установлено, что заявленные требования к сетям четвертого поколения не достигаются ни в одной из реализованных сетей, а фактическое качество обслуживания абонентов находится на достаточно низком уровне, что свидетельствует о низкой эффективности существующих методов планирования радиосетей, транспортных подсистем и методов управления. В работе были предложены альтернативные стратегии развития операторов сотовой связи в Украине. В работе впервые разработана методология повышения эффективности сотовых сетей связи, заключающаяся в использовании усовершенствованного метода планирования сети LTE для развертывания сотовых сетей нового поколения, метода оценки ключевых показателей функционирования сети сотового оператора с целью непрерывного оп-тимизации сети оператора путем использования метода оптимизации подсистемы базо вых станций развернутой сети сотового оператора, усовершенствованного метода рас-погрузки радио интерфейса сети сотового оператора с использованием подмел-режиме Wi-Fi, метода оптимизации многоуровневого транспортного сегмента сотовой сетей, метода резервирования ресурсов и балансировки нагрузки транспортной ме-режи сотового оператора и метода оценки эффективности программно-конфигурируемых сети. С помощью разработанной методологии операторам сотовой связи удается повысить эффективность своих сетей за счет увеличения радиус зон обслуживания абонентов сотовых сетей, минимизации необходимого количества базовых станций для построения сети, увеличение вдвое количества активных абонентов, обслугвуються в базовой и обеспечения балансировки нагрузки в радиопидмережи, повышение економинои эффективности транспортной сети, повышение уровня надежности сети, оптимизацией утилизации транспортных каналов, проведение более гибкого и оперативного расширения сети, внедрение новых сервисов, повышения оперативности доставки данных для иерархической структуры уровня управления.
The amount of traffic carried over wireless networks is growing rapidly and is being driven by many factors. Chief among them is the tremendous growth in multimedia applications on mobile devices – streaming music and video, two-way video conferencing and social networking to name a few. The telecoms industry is undergoing a major transformation towards 5G networks in order to fulfil the needs of existing and emerging use cases. The 5G architecture should seamlessly support both fixed and mobile access technologies under a fully converged end-to-end system in order to deliver future service requirements for some of the deployment scenarios that could be supported. This technologies in nearest future have come to Ukraine too. That’s why in this dissertation an analysis of the quality of service of subscribers of cellular networks in Ukraine was conducted in order to determine the efficiency of their operation and security. An analysis of the quality of customer service in the implemented projects of LTE networks in the world and 4G networks in Ukraine has established that the claimed requirements for fourth generation networks are not achieved in any of the implemented networks, and the actual quality of customer service (target efficiency) is at a rather low level which indicates the low efficiency of existing radio network planning methods, transport subsystems, control and cybersecurity management methods. This made it possible to determine the directions by which it is necessary to increase the efficiency of the operation of cellular networks. In this dissertation were developed several methods to improve network efficiency. The method of planning of the network of the cellular operator enables cellular operators to more accurately assess the coverage of radio coverage areas, choose key indicators of service quality, more efficient frequency planning and capital cost calculation, which in turn allows us to assess the feasibility of constructing a cellular network option. On the basis of this advanced method, a training software (web-application) was developed to evaluate radio coverage zones of LTE network base stations. The method for evaluating key indicators of service quality, the level of information security and the efficiency of cellular networks makes it possible to assess the most important indicators of the quality of functioning and security of the cellular network network in order to continuously monitor and optimize them when introducing new services during customer service. The method for optimizing the subsystem of base stations allows to increase the radius of subscriber service areas of cellular networks, which allows minimizing the number of base stations for network construction, and therefore reduce the cost of the cellular operator to build the subsystem of the base stations, that is, increase the economic efficiency of the network. Improved method of the radio interface off-loading using a non-3GPP standard subnet allow to reduce the load on the radio interface of the network of the cellular network to an acceptable level, double the number of active subscribers, which are served in the cell, and provide load balancing and increase the efficiency of the radio subnetwork. The method of optimization of a multi-level transport segment of a cellular network has been developed, which allows to improve the structure of the transport network during the transition to new generations networks, providing the necessary capacity and increasing and improving the efficiency of the transport network. The method of routing with resource reservation and balancing of the traffic of a cellular operator with the consideration of information security requirements allows to increase the efficiency of the transport channels usage. The method for evaluating the effectiveness of a software-configured network allows for a more flexible and operational expansion of the network, the introduction of new services, increasing the efficiency of data delivery for the hierarchical structure. The method of network-centric monitoring and response to cyber incidents in the network of the cellular network allows real-time monitoring of the state of cyber security, its level and, consequently, the efficiency of the cellular network. On the base of these methods in this dissertation was developed cellular networks efficiency improving methodology, which is using the improved method of LTE network planning, the key method for assessing performance of the cellular operator for the purpose of continuous operator network optimizing using the method of base station subsystem optimization, improved method of radio interface of the cellular operator offloading using Wi-Fi, the method of optimization of multi-vehicle segment of the cellular network, the method of roating with resource reservation and load balancing of mobile operator and method of SDN network effectiveness evaluation. Using the developed methodology mobile operators can improve the efficiency of their networks by increasing the radius of the service areas, minimizing the required number of base stations for the construction of the network, doubling the number of active subscribers in the cell and provide load balancing in transport and radio network, increase transport network efficiency, enhance network reliability, optimize utilization of transport channels for a more flexible and rapid network expansion, introduction of new services and improved data delivery in the hierarchical structure of SDN. It is advisable to use the obtained scientific results when planning LTE and 5G wireless networks, developing equipment and software for data transmission systems, as well as in the learning process.
Tsao, Sheng-Kai, and 曹勝凱. "A tissue attenuation coefficient estimation technique using bubble harmonic signals." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/25443834502520282258.
Повний текст джерелаYa-TingTsai and 蔡亞庭. "Effects of Operational Mode and Attenuation on the Characterization of Biological Tissues with Ultrasonic Backscattering Signals and Statistical Analysis." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/16203098037229791030.
Повний текст джерела國立成功大學
醫學資訊研究所
103
The Nakagami statistical distribution of ultrasonic backscattering signals has shown it is capable of characterizing the variations of density and arrangement of scatterers in biological tissues. This analysis of ultrasound signals has also found with less dependency on the effect of attenuation and the estimated statistical parameter can be affected by the board-band attenuation in the tissues and distortion of acquired echo signals. Accordingly, as the employed ultrasound frequency and pulse duration, namely operational mode, were increased, several additional factors could come into play and further affect the precise estimation of the statistical parameters. To further investigate the addressed issues, experiments were arranged and performed using 3.5, 7.5, and 10MHz focused transducer in vitro porcine liver tissues and using 30, 50MHz focused transducer in vivo rat liver tissues. The porcine liver tissues were obtained with either healthy (N=10) or pathological fibrosis (N=10) were obtained from a local slaughter house, and rat liver tissues from 10-week-old male Sprague Dawley (SD) rat liver tissues (N=5). Various excitation cycles, including 1, 3, 5, and 10, of tone bursts at pulse repetition frequency corresponding to ultrasound frequencies of 3.5, 7.5, 10, 30 and 50 MHz were adjusted for driving the transducers. Various thickness of attenuated phantoms with the attenuation coefficient of 1.62 dB/mm.MHz were placed on the surface of tissue to be measured. The Nakagami statistical model, which includes the shape parameter (Nakagami-m), was implemented to assess variations of the probability density function (PDF) estimated from the acquired ultrasonic backscattering signals. Eventually, the histological analysis, using the H&E staining, not only detect the pathological fibrosis liver status but also measure the number of scatterers in the resolution cell, it’s corresponds to a volume of ultrasound signals within transducer pulse length and the lateral profile beamwidths. Results of in vitro porcine liver tissues indicated that the attenuation could significantly vary the shape of PDF of backscattered envelopes. Results of in vivo rat liver tissues indicated that the Nakagami-m increased with the increasing ultrasound frequencies and bandwidth, and that those associated PDFs were nearly pre-Rayleigh distributed. Results of histological analysis are shown the stronger scatterers distributed in the tissues, the characterization of tissues both describe to pre-Rayleigh distribution. All the results consistently demonstrated that the use of 3 cycles tone bursts may achieve the most appropriate performance to accommodate a trade-off between attenuation effect and image resolution. Current study also verified that the operational modes of incident ultrasound need to be properly assured before that the statistical model may be further applied to parametric imaging and clinical applications.
Seyedi, Mirhojjat. "A Novel Intrabody Communication Transceiver for Biomedical Applications." Thesis, 2014. https://vuir.vu.edu.au/25847/.
Повний текст джерелаLin, Wen-Jin, and 林文進. "Signal Attenuation on Three-Phase Power Distribution Lines with Field Test Data." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/41540469670867749446.
Повний текст джерела國立臺灣科技大學
工程技術研究所
81
Distribution-Line-Carrier (DLC) can serve as a meduim of two- way communication for load management and distribution automation. Attenuation analysis of DLC signal along complicated distribution systems network is indispensable to achieving an acceptable level of reliability to satisfy two-way communication requirements on DLC communication system. In this thesis, emphasis has been placed on analyzing the DLC from calculation of the distributed parameters of overhead line and underground cable in distribution systems to the derivation of their equivalent PI models. In addition, the distribution transformer models of various connection configurations are derived in detail. A general computer program coded in C language has been developed for analyzing the distribution-line- carrier signal of the distribution systems. Finally, the Carolina power and light company's distribution test site and the Tai-power two-way communication demonstration system will be taken as illustrative examples to carry out the comparison of computer simulation with field test data.
Chou, Yen-Ting, and 周彥廷. "Applying Image Processing Technology to cognize the Signal Attenuation of annel Characteristic Function." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/dz382f.
Повний текст джерела國立彰化師範大學
電機工程學系
107
This thesis uses the loop diagnostic method (Web Base LDM) developed by the telecommunications service provider to perform image recognition for the ultra-high-speed digital data rate (VDSL) and the inner loop signal attenuation response map (HLog). First, the system uses the Unicom labeling method to mark the position of the desired image, and then use the color separation and graphic redraw to convert the original image into a MATLAB coordinate map. First, it uses rule of thumb to find out the graphic characteristics of common obstacles, and then determine the cause of the obstacles on the coordinate map after redrawing of the graphs. Finally, the system compares them with the situation at the scene. If there is any difference, the data should be recorded to make the basis for interpretation by identifying its characteristic. The experimental results can be used to help the interpretation of obstacles for newcomers and the people who are not familiar with the Web Base LDM system.
Tzou, Chi-Min, and 鄒啟民. "A Study of Low-Orbit-Satellite Signal at Ka-Band Affected by Rain Attenuation in Taiwan." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/74187989230897377504.
Повний текст джерела國立中央大學
太空科學研究所
85
The ROCSAT-1 with the missions of space research, earth- space communication and remote sensing is about to be launchedin the end of 1998 or at the begin of 1999. By the specifica-tions of the original desigins, the freqrncy for the earth- earthcommunication of the ROCSAT-1 is ranged in the Ka band ( 30GHz for uplink, 20 GHz for downlink). While millimeter wavespropagate through the atmospheric chanel, the degradation ofpropagation may take place, such as the attenuation and thedepolarization by raindrops, the absorption by oxygen andwater vapor, and the scintillation by atmospheric turbulance. Taiwan, for the understanding of the propagation propertiesat Ka band. In the whole context, the attenuation by rain iscalculated under differert latitude through the analyzation ofrainy data from Central Weather Bureau.
DESIDERI, Francesco Saverio. "Measurements and estimation of seismic attenuation for near-surface site characterization." Doctoral thesis, 2020. http://hdl.handle.net/11573/1365525.
Повний текст джерелаDESIDERI, Francesco Saverio. "Measurement and estimation of seismic attenuation for near-surface site characterization." Doctoral thesis, 2020. http://hdl.handle.net/11573/1364692.
Повний текст джерелаWolsieffer, Casey. "Correcting For Terrain Interference, Attenuation, and System Bias for a Dual Polarimetric, X-Band Radar." 2021. https://scholarworks.umass.edu/masters_theses_2/1030.
Повний текст джерелаJan, Min-Chau, and 詹閔超. "A Local Centralized Weighted Interpolation Positioning Scheme Based on Signal Attenuation Difference of Arrival in Wireless Sensor Networks." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/pq3wtd.
Повний текст джерела國立臺北科技大學
電腦與通訊研究所
99
In recent years, the rapid development of wireless sensor networks (WSNs) is obvious. It will change interactive mode between humans and the objectives. Numerous sensor nodes are deployed in object areas, which can realize tasks of complex large-range monitoring and tracking. However, for most of applications, the data ,which are collected by the sensor, is meaningless unless the location information. In this thesis, we design a local centralized positioning scheme for indoor wireless sensor networks. The proposed method combines the advantages of centralized positioning and decentralized positioning scheme, and based on signal attenuation difference of arrival to improve the location accuracy. It utilizes recursive weighted interpolation method to compute the target location. In addition, the life time and bandwidth efficiencies of whole WSNs are accomplished because of the sensed data are processed in the user’s handheld and need not be transmitted to the sever. The simulation results show that our method has better location performance then other positioning schemes.
Malinga, Senzo Jerome. "Determination of millimetric signal attenuation due to rain using rain rate and raindrop size distribution models for Southern Africa." Thesis, 2014. http://hdl.handle.net/10413/11206.
Повний текст джерелаThesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2014.
Бартиш, Андрій Андрійович. "Дослідження волоконно-оптичної системи передачі інформації та розробка фотоприймального пристрою". Магістерська робота, 2020. https://dspace.znu.edu.ua/jspui/handle/12345/4861.
Повний текст джерелаUA : Розроблено фізичну модель фотоприймального пристрою для волоконно-оптичної системи передачі інформації, що дозволяє зменшити вплив шумів на спотворення електричного сигналу у інтерфейсному обладнанні.
EN : A physical model of a photodetector device for a fiber-optic information transmission system has been developed, which allows to reduce the influence of noise on the distortion of the electrical signal in the interface equipment.
Richter, Katja. "Analyse von full-waveform Flugzeuglaserscannerdaten zur volumetrischen Repräsentation in Umweltanwendungen." 2018. https://tud.qucosa.de/id/qucosa%3A32349.
Повний текст джерелаThe scientific investigation of terrestrial and aquatic ecosystems requires precise information on the three-dimensional structure of the ecologic system. Full-waveform airborne laser scanner data are an ideal basis for the complete volumetric representation of vegetation and water structure in a voxel space. Due to attenuation effects, caused by partial reflections during the laser pulse propagation through the vegetation or water column, each individual laser pulse echo is significantly modified. As a result, the structure in the lower parts of the vegetation or water column is underrepresented in the digitized waveform. Within this research, novel and innovative methods were developed, which enable the generation of a radiometrically correct voxel space representation. Therefore, a numerically stable reconstruction of the effective differential backscattering cross section utilizing appropriate deconvolution and regularization techniques is required. The essential element of the analysis is the description of the signal attenuation using applicable mathematical models. For this purpose, novel correction methods compensating the signal attenuation based on these models were developed. The correction term is directly derived from the differential backscatter cross section. The basic idea is a gradually increase of the signal amplitudes depending on the individual history of each laser pulse. The results gained in this work contribute to an improved access to the information on vegetation and water structure, contained in full-waveform laser scanner data. Furthermore, it is possible to overcome limitations of existing approaches, which are mainly based on the extraction of discrete maxima.
Cai, Zibo. "Impulse radio intrabody communication system for wireless body area networks." Thesis, 2015. https://vuir.vu.edu.au/26283/.
Повний текст джерела(11178318), Debayan Das. "Advanced EM/Power Side-Channel Attacks and Low-overhead Circuit-level Countermeasures." Thesis, 2021.
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