To see the other types of publications on this topic, follow the link: Time burst.
Dissertations / Theses on the topic 'Time burst'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Time burst.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Maneekul, Jindanuch. "Exploration of Genome Length, Burst Time, and Burst Size of Streptomyces griseus Bacteriophages." Thesis, University of North Texas, 2019. https://digital.library.unt.edu/ark:/67531/metadc1505188/.
Full textAbstract:
Since phages use the host resources to replicate themselves after infection, the different sizes of the phage genome should influence the replication rate. We, therefore, hypothesized that the smaller genomes should burst the cell faster than the larger ones. As well, the shorter genomes would have greater burst sizes because they should replicate faster. Here, we obtained 16 phages of various genome length. All phages were isolated on Streptomyces griseus and available in our phage bank at the University of North Texas. We performed one-step growth studies for the 16 phages, as well as determined the host doubling time from its growth curve. The results show that S. griseus grown in nutrient broth has a doubling time of 5 hours and 22 minutes. This doubling time is used as a guideline for the phage growth studies. Because the filamentous nature of the host caused several difficulties during the experiment, we isolated single cells by sonication and centrifugation. After the cell number was determined by viable cell count, the cells were infected with each type of phage using a multiplicity of infection (MOI) of 0.5. The results show that phages' burst times range between 45 (±0, standard error) and 420 (±30) minutes and burst sizes from 12 (±0) to 1500 (±60) The statistical analyses show that there is no correlation between either genome size and burst time (R= -0.01800, P=0.97894) or genome size and burst size (R= -0.32678, P=0.21670). We further performed the comparative genomics studies to investigate whether the phages with similar burst times and burst sizes show similar genome structures. The studies show that Eddasa and Lorelei have similar burst times of 45 to 60 minutes and share 52 homologs. For burst size, only Tribute and Blueeyedbeauty that have similar burst sizes of 21-30, and they are genetically related because of the 48 shared homologs. Although this study did not find any correlation between genome size and burst time/burst size, it provides a foundation for further studies to determine what regulates these two traits.
2
Klinkowski, Miroslaw. "Offset time-emulated architecture for optical burst switching-modelling and performance evaluation." Doctoral thesis, Universitat Politècnica de Catalunya, 2008. http://hdl.handle.net/10803/6000.
Full textAbstract:
L'evolució de les xarxes publiques de transport de dades destaca per el continu augment de la demanda de tràfic a la que estan sotmeses. La causa és la imparable popularització d'Internet i del seu ús per a tot tipus d'aplicacions. Les xarxes de commutació de ràfegues òptiques (OBS: Optical Bursts Switching) són una solució extraordinàriament prometedora per la pròxima generació de xarxes, tant per la flexibilitat que ofereixen com per el seu alt rendiment fruit de l'explotació de la multiplexació estadística en el domini òptic.<br/><br/>Aquesta tesi presenta l'anàlisi, modelització i avaluació de les xarxes de commutació de ràfegues òptiques basades en l'emulació del temps de compensació (emulated offset time: E-OBS). El concepte d'E-OBS defineix una arquitectura de xarxa OBS per al transportar i commutar ràfegues òptiques en una xarxa troncal en la que, al contrari de l'arquitectura convencional (C-OBS) en la que el temps de compensació s'introdueix des dels nodes d'accés, el temps de compensació s'introdueix en cadascun dels nodes de la xarxa per mitjà d'un retardador de fibra addicional. L'arquitectura E-OBS permet superar algunes de les desavantatges inherents a arquitectures C-OBS, però la seva gran virtut és la compatibilitat amb les xarxes de commutació de circuits òptics (OCS: Optical Circuit Switching) actuals i les futures xarxes de commutació de paquets òptics (OPS: Optical Packet Switching), de manera que les xarxes OBS basades en una arquitectura E-OBS) poden facilitat enormement la transició de unes a les altres.<br/><br/>A ala vista dels principals requeriments de disseny de les xarxes OBS, que són la resolució de contencions en el domini òptic, la provisió de qualitat de servei (QoS) i l'òptim encaminament de les ràfegues per tal de minimitzar la congestió de la xarxa, . en aquesta tesi es proposa un disseny de l'arquitectura E-OBS basada en (i) un mètode viable per a la provisió del temps de compensació, (ii) una qualitat alta global de servei, i (iii) un mecanisme d'encaminament que minimitzi congestió de xarxa.<br/><br/>- La primera part d'aquesta tesi proporciona la informació documental necessària per al disseny d'E-OBS.<br/><br/>- La segona part se centra en l'estudi de la funcionalitat i viabilitat de l'arquitectura E-OBS. S'introdueixen els principis d'operació d'E-OBS i s'identifiquen els principals esculls que presenten les arquitectures C-OBS i que deixen de ser-ho en una arquitectura E-OBS. Alguns d'aquests esculls són la dificultat d'utilitzar un algorisme d'encaminament amb rutes alternatives, la complexitat dels algoritmes de reserva de recursos i la seva falta d'equitat, la complexitat en la provisió de la QoS, etc. En aquesta segona part es constata que l'arquitectura E-OBS redueix la complexitat dels de reserva de recursos i es verifica la viabilitat d'operació i de funcionament de la provisió del tremps de compensació en aquesta arquitectura a partir de figures de comportament obtingudes amb retardadors de fibra comercialment disponibles.<br/><br/>- La tercera part encara el problema de la provisió de la QoS. Primer s'hi revisen els conceptes bàsics de QoS així com els mecanismes de tractament de la QoS per a xarxes OBS fent-ne una comparació qualitativa i de rendiment de tots ells. Com a resultat s'obté que el mecanisme que presenta un millor comportament és el d'avortament de la transmissió de les ràfegues de més baixa prioritat quan aquestes col·lisionen amb una de prioritat més alta (es l'anomenat Burst Preemption mechanism), el qual en alguns casos presenta un problema de senyalització innecessària. Aquesta tercera part es conclou amb la proposta d'un mecanisme de finestra a afegir al esquema de Burst Preemption que només funciona sobre una arquitectura E-OBS i que soluciona aquest problema.<br/><br/>- En la quarta part s'afronta el problema de l'encaminament en xarxes OBS. S'estudia el comportament dels algoritmes d'encaminament adaptatius, els aïllats amb rutes alternatives i els multicamí distribuïts, sobre xarxes E-OBS. A la vista dels resultats no massa satisfactoris que s'obtenen, es planteja una solució alternativa que es basa en model d'optimització no lineal. Es formulen i resolen dos models d'optimització per als algoritmes encaminament de font multicamí que redueixen notablement la congestió en les xarxes OBS.<br/><br/>Finalment, aquesta tesi conclou que l'arquitectura E-OBS és factible, que és més eficient que la C-OBS, que proveeix eficaçment QoS, i que és capaç d'operar amb diverses estratègies d'encaminament i de reduir eficaçment la congestió de xarxa.<br>The fact that the Internet is a packet-based connection-less network is the main driver to develop a data-centric transport network. In this context, the optical burst switching (OBS) technology is considered as a promising solution for reducing the gap between transmission and switching speeds in future networks.<br/><br/>This thesis presents the analysis, modelling, and evaluation of the OBS network with Emulated offset-time provisioning (E-OBS). E-OBS defines an OBS network architecture to transport and switch optical data bursts in a core network. On the contrary to a conventional offset-time provisioning OBS (C-OBS) architecture, where a transmission offset time is introduced in the edge node, in an E-OBS network the offset time is provided in the core node by means of an additional fibre delay element. The architecture is motivated by several drawbacks inherent to C-OBS architectures. It should be pointed out that the E-OBS has not been studied intensively in the literature and this concept has been considered rather occasionally.<br/><br/>Due to the limitations in optical processing and queuing, OBS networks need a special treatment so that they could solve problems typical of data-centric networks. Contention resolution in optical domain together with quality of service (QoS) provisioning for quality demanding services are, among other things, the main designing issues when developing OBS networks. Another important aspect is routing problem, which concerns effective balancing of traffic load so that to reduce burst congestion at overloaded links. Accounting for these requirements, the design objectives for the E-OBS architecture are (i) feasibility of offset-time provisioning, (ii) an overall high quality of service, and (iii) reduction of network congestion. These objectives are achieved by combining selected concepts and strategies, together with appropriate system design as well as network traffic engineering.<br/><br/>The contributions in this thesis can be summarized as follows.<br/><br/>- At the beginning, we introduce the principles of E-OBS operation and we demonstrate that C-OBS possesses many drawbacks that can be easily avoided in E-OBS. Some of the discussed issues are the problem of unfairness in resources reservation, difficulty with alternative routing, complexity of resources reservation algorithms, efficiency of burst scheduling, and complexity in QoS provisioning. The feasibility of E-OBS operation is investigated as well; in this context, the impact of congestion in control plane on OBS operation is studied. As a result, we confirm the feasibility of E-OBS operation with commercially available fibre delay elements.<br/><br/>- Then, we provide both qualitative and quantitative comparison of the selected, most addressed in the literature, QoS mechanisms. As an outcome a burst preemption mechanism, which is characterized by the highest overall performance, is qualified for operating in E-OBS. Since the preemptive mechanism may produce the overbooking of resources in an OBS network we address this issue as well. We propose the preemption window mechanism to solve the problem. An analytical model of the mechanism legitimates correctness of our solution.<br/><br/>- Finally, we concern with a routing problem - our routing objective is to help the contention resolution algorithms in the reduction of burst losses. We propose and evaluate two isolated alternative routing algorithms designed for labelled E-OBS networks. Then we study multi-path source routing and we use network optimization theory to improve it. The presented formulae for partial derivatives, to be used in a non-linear optimization problem, are straightforward and very fast to compute. It makes the proposed non-linear optimization method a viable alternative for linear programming formulations based on piecewise linear approximations.<br/><br/>Concluding, E-OBS is shown to be a feasible OBS network architecture of profitable functionality, to support efficiently the QoS provisioning, and to be able to operate with different routing strategies and effectively reduce the network congestion.
3
Choi, Yiu Kuen. "Adaptive traffic regulation at the burst level for real time ATM applications." Thesis, University of Sunderland, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339543.
Full text
4
Cusack, Stephen D. "Integer-time burst-level simulation techniques for very high speed communication networks." Thesis, University of Edinburgh, 2000. http://hdl.handle.net/1842/23315.
Full textAbstract:
This thesis presents a technique which abstracts the level of detail of a cell-based network to the <i>burst level,</i> where a burst describes a group of cells in transmission. the use of the burst is designed to reduce the number of events which must be processed to perform a network simulation. To leverage the power of today's inexpensive, high performance microprocessors, the techniques presented exclusively use all-integer arithmetic. The use of integer arithmetic provides an inherent performance gain over floating point arithmetic. The use of 64-bit integer arithmetic is very desirable, which is a completely realistic goal for the next generation of microprocessors. Techniques using integer arithmetic to multiplex, queue, demultiplex and switch bursts of cells are presented. Each operation is presented as a simulation object integrated into an efficient C++-based object-oriented bespoke simulation environment. The accuracy and performance issues for each object are explored, in comparison with an efficient cell level simulator also developed in the work. Detailed investigation of the proposed techniques highlights two core operations, which are then further optimised as integer techniques (by removing the integer divide operation). The revised integer techniques are shown to improve the performance of the simulation objects, while preserving the accuracy of the techniques. Three basic experiments are presented in the thesis to show how non-trivial simulations can be constructed from the core simulation objects presented. The performance and accuracy implications of each experiment are analysed and used to provide guidance for further work based on the techniques presented.
5
Zhang, Wei Vicky, and 張微. "Alternative methods in neonatal hearing screening: tone-burst otoacoustic emissions and time-frequencyfiltering." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B41633854.
Full text
6
Gupta, Shalabh. "Photonic time stretch analog-to-digital conversion for high resolution and real-time burst sampling of ultra-wideband signals." Diss., Restricted to subscribing institutions, 2009. http://proquest.umi.com/pqdweb?did=2026639441&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
Full text
7
Zhang, Wei Vicky. "Alternative methods in neonatal hearing screening tone-burst otoacoustic emissions and time-frequency filtering /." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B41633854.
Full text
8
Mori, Masamitsu. "Long time supernova simulation and search for supernovae in Super-Kamiokande IV." Doctoral thesis, Kyoto University, 2021. http://hdl.handle.net/2433/263465.
Full text
9
Salter, Philip James Charles. "Time-reversed measurement of the 18Ne(α,p)21Na cross-section for Type I X-ray bursts". Thesis, University of Edinburgh, 2012. http://hdl.handle.net/1842/6239.
Full textAbstract:
Type I X-ray bursts (XRB) are highly energetic and explosive astrophysical events, observed as very sudden and intense emissions of X-rays. X-ray bursts are believed to be powered by a thermonuclear runaway on the surface of a neutron star in a binary system. XRB models are dependent on the accurate information of the nuclear reactions involved. The 18Ne(α,p)21Na reaction is considered to be of great importance as a possible breakout route from the Hot-CNO cycle preceding the thermonuclear runaway. In this thesis work, the 18Ne(α,p)21Na reaction cross-section was indirectly measured at Ecm(α,p) = 2568, 1970, 1758, 1683, 1379 and 1194 keV, using the time-reverse 21Na(p,α)18Ne reaction. Since the time-reverse approach only connects the ground states of 21Na and 18Ne, the cross sections measured here represent lower limits of the 18Ne(α,p)21Na cross-section. An experiment was performed using the the ISAC-II facility at TRIUMF, Vancouver, Canada. A beam of 21Na ions was delivered to a polyethylene (CH2)n target placed within the TUDA scattering chamber. The reaction 18Ne and 4He ions were detected using silicon strip detectors, with time-of-flight and ΔE/E particle identification techniques used to distinguish the ions from background. The measurement at Ecm = 1194 keV is the lowest energy measurement to date of the 18Ne(α,p)21Na cross section. The measured cross sections presented in this thesis were compared to the NON-SMOKER Hauser-Feshbach statistical calculations of the cross section and to the unpublished results of another time-reverse investigation performed by a collaboration at the Argonne National Laboratory. A 18Ne(α,p)21Na reaction rate calculation based on the measured cross sections was performed. In comparison with previous reaction rate estimates, our results indicate a rate that is about a factor 2-3 lower than Hauser-Feshbach calculations, suggesting that a statistical approach may not be appropriate for cross section calculations for nuclei in this mass region. The astrophysical consequences of our new results appear to remain nevertheless negligible. These are also presented in this thesis.
10
Sawano, Tatsuya. "Simulation Study on an Electron-Tracking Compton Camera for Deep Gamma-ray Burst Search." 京都大学 (Kyoto University), 2017. http://hdl.handle.net/2433/225397.
Full text
11
Zollino, Giancarlo. "Big Data for the Real-Time Analysis of the Cherenkov Telescope Array Observatory." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/17459/.
Full textAbstract:
Lo scopo di questo lavoro di tesi è quello di progettare e sviluppare un framework che supporti l'analisi in tempo reale nel contesto del Cherenkov Telescope Array (CTA). CTA è un consorzio internazionale che comprende 1420 membri provenienti da oltre 200 istituti da 31 Nazioni. CTA punta ad essere il più grande e più sensibile osservatorio ground-based di raggi gamma di prossima generazione in grado di gestire un'elevata quantità di dati e un'alta velocità di trasmissione, compresa tra i 0,5 e i 10 GB/s, con una rate di acquisizione nominale di 6 kHz. A tale riguardo, è stata sviluppata la RTAlib in grado di fornire un'API semplice e ad alte prestazioni per archiviare o fare caching dei dati generati durante la fase di ricostruzione e analisi. Per far fronte alle elevate velocità di trasmissione di CTA, la RTAlib sfrutta il multiprocesso, il multi-threading, le transazioni ed un accesso trasparente a MySQL o Redis per far fronte a diversi casi d’uso. Tutte queste funzionalità sono state testate ottenendo risultati entro i requisiti richiesti. In particolare, con la libreria sviluppata si riesce a fare caching di dati con Redis, con processi scrittori e lettori che lavorano in parallelo, ad una rate di 8 kHz in scrittura e 30 kHz in lettura.
Il team in cui ho lavorato ha basato sui principi dell'approccio Scrum e DevOps il proprio processo di sviluppo del software, in particolare dalle unit test fino alla continuous integration, utilizzando tools ad accesso pubblico su GitHub oppure tramite Jenkins. Grazie a questo approccio si è puntato ad avere una elevata qualità del codice fin dall’inizio del progetto, e questo è risultato uno degli approcci più importanti per ottenere i risultati raggiunti.
12
Mahmoud, Herman Abdulqadir Mahmoud. "Real-time operational response methodology for reducing failure impacts in water distribution systems." Thesis, University of Exeter, 2018. http://hdl.handle.net/10871/33492.
Full textAbstract:
Interruption to water services and low water pressure conditions are commonly observed problems in water distribution systems (WDSs). Of particular concern are the unplanned events, such as pipe bursts. The current regulation in the UK requires water utilities to provide reliable water service to consumers resulting in as little as possible interruptions and of as short possible duration. All this pushes water utilities toward developing and using smarter responses to these events, based on advanced tools and solutions. All with the aim to change network management style from reactive to a proactive, and reduce water losses, optimize energy use and provide better services for consumers. This thesis presents a novel methodology for efficient and effective operational, short time response to an unplanned failure event (such as pipe burst) in a WDS. The proposed automated, near real-time operational response methodology consists of isolating the failure event followed by the recovery of the affected system area by restoring the flows and pressures to normal conditions. The isolation is typically achieved by manipulating the relevant on/off valves that are located closely to the event location. The recovery involves selecting an optimal combination of suitable operational network interventions. These are selected from a number of possible options with the aim to reduce the negative impact of the failure over a pre-specified time horizon. The intervention options considered here include isolation valve manipulations, changing the pressure reducing valve’s (PRV) outlet pressure and installation and use of temporary overland bypasses from a nearby hydrant(s) in an adjacent, unaffected part of the network. The optimal mix of interventions is identified by using a multi-objective optimization approach driven by the minimization of the negative impact on the consumers and the minimization of the corresponding number of operational interventions (which acts as a surrogate for operational costs). The negative impact of a failure event was quantified here as a volume of water undelivered to consumers and was estimated by using a newly developed pressure-driven model (PDM) based hydraulic solver. The PDM based hydraulic solver was validated on a number of benchmark and real-life networks under different flow conditions. The results obtained clearly demonstrate its advantages when compared to a number of existing methods. The key advantages include the simplicity of its implementation and the ability to predict network pressures and flows in a consistently accurate, numerically stable and computationally efficient manner under both pressure-deficient and normal-flow conditions and in both steady-state and extended period simulations. The new real-time operational response methodology was applied to a real world water distribution network of D-Town. The results obtained demonstrate the effectiveness of the proposed methodology in identifying the Pareto optimal network type intervention strategies that could be ultimately presented to the control room operator for making a suitable decision in near real-time.
13
Messinger, Robert James. "Microfluidics Mathematical modeling and empirical analysis of the burst frequencies of a novel fishbone capillary valve and the development of an algorithm to calculate its hold time /." Connect to resource, 2006. http://hdl.handle.net/1811/6429.
Full textAbstract:
Thesis (Honors)--Ohio State University, 2006.<br>Title from first page of PDF file. Document formatted into pages: contains 61 p.; also includes graphics. Includes bibliographical references (p. 44-45). Available online via Ohio State University's Knowledge Bank.
14
Many, Florian. "Combinaison des aspects temps réel et sûreté de fonctionnement pour la conception des plateformes avioniques." Thesis, Toulouse, ISAE, 2013. http://www.theses.fr/2013ESAE0005/document.
Full textAbstract:
La conception des plateformes aéronautiques s’effectue en tenant compte des aspects fonctionnels et dysfonctionnels prévus dans les scénarios d’emploi des aéronefs qui les embarquent. Ces plateformes aéronautiques sont composées de systèmes informatiques temps réel qui doivent à la fois être précises dans leurs calculs, exactes dans l’instant de délivrance des résultats des calculs, et robustes à tout évènement pouvant compromettre le bon fonctionnement de la plateforme.Dans ce contexte, ces travaux de thèse abordent les ordonnancements temps réel tolérants aux fautes. Partant du fait que les systèmes informatiques embarqués sont perturbés par les ondes électromagnétiques des radars, notamment dans la phase d’approche des aéronefs, ces travaux proposent une modélisation des effets des ondes, dite en rafales de fautes. Après avoir exploré le comportement de l’ordonnanceur à la détection d’erreurs au sein d’une tâche, une technique de validation, reposant sur le calcul de pire temps de réponse des tâches, est présentée. Il devient alors possible d’effectuer des analyses d’ordonnançabilité sous l’hypothèse de la présence de rafales de fautes. Ainsi, cette technique de validation permet de conclure sur la faisabilité d’un ensemble de tâches en tenant compte de la durée de la rafale de fautes et de la stratégie de gestion des erreurs détectées dans les tâches.Sur la base de ces résultats, les travaux décrits montre comment envisager l’analyse au niveau système. L’idée sous-jacente est de mettre en évidence le rôle des ordonnancements temps réel tolérants aux fautes dans la gestion des données erronées causées par des perturbations extérieures au système.Ainsi, le comportement de chaque équipement est modélisé, ainsi que les flots de données échangés et la dynamique du système. Le comportement de chaque équipement est fonction de la perturbation subie, et donne lieu à l’établissement de la perturbation résultante, véritable réponse dysfonctionnelle de l’équipement à une agression extérieure<br>The design of avionic platforms takes into account the functional and dysfunctional aspects, which depend on the aircraft operation concept. These avionic platforms embed computer resources that must produce accurate results at the right time, and must be dependable whatever the disturbance.In this specific context, we address the topic of fault tolerant real time scheduling. Since the embedded computer resources are disturbed by electromagnetic waves produced by radar, especially during the aircraft approach, we suggest a model of these wave effects named fault bursts. Afterthe analysis of scheduler behaviour when an error is dectected inside a task, we present a validation technique based on the evaluation of the worst case response time. By this way, we are able to study the task set feasibility under fault burst assumption and according to the error recovery strategy.Then, based on these results, we show a way to analyse the effects of disturbances such as electromagnetic waves at system level. The underlining idea is to demonstrate the main role of fault tolerant real time scheduler in the management of erroneous data. To do that, we suggest an equipment model which integrates the behaviour of the equipement when a disturbance occurs. We also describe thedata flows in order to describe the avionics platform dynamics
15
Dalvald, Momo. "Korrelerar startlereaktion med reaktionstid?" Thesis, University of Gävle, Department of Education and Psychology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-321.
Full textAbstract:
<p>Bilder av potentiella hot upptäcks snabbt och leder till en snabbare reaktionstid än bilder av icke-potentiella hot. Potentiella hot stjäl också fokus och kognitiva resurser, med en långsammare reaktionstid som följd. Rädsla, som kan mätas genom startlereflexen, leder till antingen ökad handlingsberedskap (snabbare reaktionstid) eller kognitiv distraktion (långsammare reaktionstid). Fem försöksdeltagare fick reagera på en visuell probe som lades ovanpå djurbilder, både potentiella hot och icke-potentiella hot i ett kombinerat reaktionstids- och startleprobeexperiment, där ljudstötar utdelades i hörlurar. Startlereaktion, hjärtfrekvens och reaktionstid mättes, varefter korrelationskoefficienter räknades ut. Resultatet visade på en svag negativ korrelation mellan reaktionstid och startlepotentiering på gruppnivå, men inga signifikanta samband påvisades på individnivå. Resultatet på gruppnivå kan bero på att de individuella resultaten tenderar samlas i kluster och därför skapar ett skensamband. Även en positiv korrelation mellan hjärtfrekvensförändring och startlereaktion påvisades, men ingen korrelation mellan hjärtfrekvens och reaktionstid.</p><br><p>Pictures of fear relevant animals are detected fast and lead to shorter reaction time, compared to pictures of fear irrelevant animals. Fear relevant animals also capture attention and steals focus, which leads to slower reaction time. Fear leads to either preparedness for action (faster reaction time) or cognitive distraction (slower reaction time). In a combined startle probe and reaction time experiment, five participants were requested to react to a visual probe, superimposed on pictures of animals, both relevant and irrelevant to fear. Startle probes were given as noise bursts in headphones. Startle reaction, heart rate and reaction time were measured. A negative correlation between reaction time and startle potentiation was found on group level, whereas no significant correlations were found on the individual level. However, the individual results tend to gather in clusters, which might give a significant result on group level even if there is none.</p>
16
Brandão, Jesse Wayde. "Analysis of the truncated response model for fixed priority on HMPSoCs." Master's thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/14836.
Full textAbstract:
Mestrado em Engenharia Electrónica e Telecomunicações<br>With the ever more ubiquitous nature of embedded systems and their increasingly
demanding applications, such as audio/video decoding and networking,
the popularity of MultiProcessor Systems-on-Chip (MPSoCs) continues
to increase. As such, their modern uses often involve the execution
of multiple applications on the same system. Embedded systems often have
applications that are faced with timing restrictions, some of which are deadlines,
throughput and latency. The resources available to the applications
running on these systems are nite and, therefore, applications need to share
the available resources while guaranteeing that their timing requirements are
met.
These guarantees are established via schedulers which may employ some of
the many techniques devised for the arbitration of resource usage among
applications. The main technique considered in this dissertation is the Preemptive
Fixed Priority (PFP) scheduling technique.
Also, there is a growing trend in the usage of the data
ow computational
model for analysis of applications on MultiProcessor System-on-Chips (MPSoCs).
Data
ow graphs are functionally intuitive, and have interesting and
useful analytical properties.
This dissertation intends to further previous work done in temporal analysis
of PFP scheduling of Real-Time applications on MPSoCs by implementing
the truncated response model for PFP scheduling and analyzing the its
results. This response model promises tighter bounds for the worst case
response times of the actors in a low priority data
ow graph by considering
the worst case response times over consecutive rings of an actor rather
than just a single ring.
As a follow up to this work, we also introduce in this dissertation a burst
analysis technique for actors in a data
ow graph.<br>Com a natureza cada vez mais ubíqua de sistemas embutidos e as suas
aplicações cada vez mais exigentes, como a decodicação de áudio/video
e rede, a popularidade de MultiProcessor Systems-on-Chip (MPSoCs) continua
a aumentar. Como tal, os seus usos modernos muitas vezes envolvem
a execução de várias aplicações no mesmo sistema. Sistemas embutidos, frequentemente correm aplicações que são confrontadas com restrições temporais, algumas das quais são prazos, taxa de transferência e latência. Os recursos disponíveis para as aplicações que estão a correr nestes sistemas são finitos e, portanto, as aplicações necessitam de partilhar os recursos disponíveis, garantindo simultaneamente que os seus requisitos temporais sejam satisfeitos.
Estas garantias são estabelecidas por meio escalonadores que podem empregar algumas das muitas técnicas elaboradas para a arbitragem de uso de recursos entre as aplicações. A técnica principal considerada nesta dissertação é Preemptive Fixed Priority (PFP).
Além disso existe uma tendência crescente no uso do modelo computacional
data flow para a análise de aplicações a correr em MPSoCs. Grafos data flow são funcionalmente intuitivos e possuem propriedades interessantes e úteis.
Esta dissertação pretende avançar trabalho prévio na área de escalonamento
PFP de aplicações ai implementar o modelo de resposta truncatedo para escalonamento PFP e analisar os seus resultados. Este modelo de resposta promete limites mais estritos para os tempos de resposta de pior caso para atores num grafo de baixa prioridade ao considerar os tempos de resposta de pior caso ao longo de várias execuções consecutivas de um actor em vez de uma só.
Como seguimento a este trabalho, também introduzimos nesta dissertação
uma técnica para a análise de execuções em rajada de atores num grafo data flow.
17
Atteia, Jean Luc. "Profils temporels et origine des sursauts gamma : l'apport du programme signe." Toulouse 3, 1987. http://www.theses.fr/1987TOU30283.
Full textAbstract:
A partir de donnees observationnelles collectees pendant le programme signe, on etudie certaines caracteristiques de la population des sources de sursaut gamma: la structure temporelle des evenements et la distribution spatiale des sources localisees. En outre 2 etudes particulieres ont pour sujet: la recherche de sursauts optiques associes aux sursauts gamma et la localisation d'une source repetitive extraordinaire
18
Medina, Maria Mercedes Gamboa. "Detecção de vazamentos e alterações em redes de distribuição de água para abastecimento, durante a operação, usando sinais de pressão." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-27102017-095158/.
Full textAbstract:
O controle ativo de vazamentos é fundamental para o gerenciamento dos recursos hídricos, e particularmente o problema de sua detecção precisa de alternativas de solução. Nesta pesquisa foram desenvolvidos três métodos para detecção da ocorrência de vazamentos ou outras alterações em redes de distribuição de água para abastecimento, durante operação, com base na análise dos sinais de pressão adquiridos por monitoramento permanente na rede. Os métodos foram desenvolvidos com informações de um estudo de caso real, e fundamentam-se em cadeias de Markov, em controle estatístico de processos, e em comparação com padrões, respetivamente. Seu desempenho global foi quantificado com a área abaixo da curva ROC, obtendo valores médios de 0,67, 0,65 e 0,71, respetivamente. Foi encontrado que a ocorrência de vazamentos produz mudanças nas pressões medidas na rede, mas tais mudanças podem ser próximas às que acontecem pela operação normal, de forma que os métodos propostos constituem ferramentas de suporte ao gerenciamento úteis, sem atingir a detecção e diferenciação da totalidade dos vazamentos e alterações.<br>Active leak control is fundamental on water resources managment, and particullary the detection problem needs alternative solutions. On this research three methods for leak or anomaly detection on operating supply systems were developed, based on analisys of pressure signals acquired by network monitoring. The proposed methods used real data from a case study, and are based on Markov chains, statistical process control, and pattern comparison, respectively. Their overall performances on case study were measured using the area under ROC curve, reaching averages 0,67, 0,65 and 0,71, respectively. It was found that a leak onset result in disturbances on measured preassure, but sometimes those disturbances are close to those of normal operation, therefore proposed methods are useful decision tools, not reaching detection and distinction for all the leaks or anomalies.
19
Bento, Susana Gonçalves. "Transceivers for TWDM-PON." Master's thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/14570.
Full textAbstract:
Mestrado em Engenharia Eletrónica e Telecomunicações<br>In recent years, Internet has been assuming a fundamental role in
everyday life. Traffic demands are increasing in such a way that the
available technologies will presumably no longer satisfy the raised
requirements. For the last years, operators have expressed a clear
interest in the implementation and development of Passive Optical
Network (PON) to provide several services and applications to a high
flow rate per client. Comparing to other access technologies, PON is
very attractive mainly due to reduction of maintenance and to the
operational cost efficiency. As a consequence, PON systems were
standardized and developed in the whole world, but the everincreasing
bandwidth demand makes this type of network need to
evolve. Therefore, the current standardized technologies Gigacapable
PON and XG-PON need to be upgraded to Next-Generation
PON2. In order to protect the initial investment and to reduce the
operational costs, operators should keep the current optical
distribution network, providing the technologies coexistence in the
same fiber.
The principle of NG-PON2 is to improve previous technologies, in
terms of capacity, ODN compatibility, bandwidth and cost-efficiency. In
April 2012, Full Service Access Network (FSAN) selected the time and
wavelength multiplexing PON (TWDM-PON) technology as the
solution of choice for NG-PON2. Almost one year later, ITU-T G.989.1
came out, providing some wavelength plans proposals. The ability to
operate on existing fiber ODN, coexisting with legacy PON is the most
important requirement.
The current dissertation is based on the study of TWDM-PON
upstream transmission. Both GPON and XG-PON work in burst mode
for upstream direction, therefore in the current study also that type of
data transmission is considered for upstream TWDM-PON. Once
using this transmission mode, some parameters have to be taken into
consideration, as the packets size and their separation length in order
to understand which frame fits the best, considering the system
performance.
In the actual study, it was supposed to visualize transients in each
packet, however it was experimentally proved that once the lifetime of
the carriers is less than the burst time, it was not possible to identify
any of them. It was also verified that increasing the guard time will
decrease the performance of the system.<br>A Internet tem vindo a assumir um papel fundamental no
quotidiano de cada utilizador. A largura de banda exigida é cada vez
mais alta, desta forma, as tecnologias actualmente disponíveis
acabarão por deixar de satisfazer os requisitos emergentes. Nos
últimos anos, as operadoras têm manifestado um interesse evidente
no desenvolvimento de Redes Ópticas Passivas (PON), com o intuito
de fornecer vários serviços e aplicações a uma taxa de fluxo elevada
por cliente. Comparando com outras tecnologias de acesso, as redes
PON são muito actrativas devido à sua baixa manutenção e aos
custos/eficiência de operação. Como consequência, os sistemas PON
foram padronizados e desenvolvidos em todo o mundo. No entanto,
este tipo de tecnologia necessita de progredir ao longo do tempo,
mantendo a satisfação dos requisitos de tráfego que lhe serão
impostos. Assim, as tecnologias actualmente implementadas: GPON
e XG-PON, necessitam de sofrer um upgrade para NG-PON2 (Next-
Generation PON 2). De modo a proteger o investimento inicial,
reduzindo os custos de operação, as operadoras devem manter e
reutilizer a ODN já implementada, possibilitando a coexistência das
tecnologias na mesma fibra.
NG-PON2 é uma melhoria da capacidade, da compatibilidade na
ODN, largura de banda e custo-eficiência das tecnologias anteriores.
Em Abril de 2012, a FSAN selecionou a tecnologia TWDM-PON (Time
and Wavelength Division Multiplexing PON) como solução do projecto
NG-PON2. Um ano após a sua seleção, a norma ITU-T G.989.1 foi
publicada, propondo alguns planos de comprimentos de onda. A
coexistência de TWDM-PON com as PON anteriores na mesma ODN
é o requisite mais importante.
A presente dissertação baseia-se no estudo de transmissão
upstream de TWDM-PON. Ambos GPON e XG-PON operam em
modo burst para a direção upstream. Uma vez utilizao este modo de
transmissão, é necessário considerer determinados parâmetros como
o tempo de separação interburst – guard time, tal como o
comprimento de cada pacote, com o intuito de compreender o
impacto da variação destes mesmos campos no desempenho do
sistema.
No presente estudo, era susposto visualizar transientes em cada
pacote de transmissão, no entanto foi comprovado
experimentalmente, que uma vez que o tempo de vida dos portadores
do EDFA selecionado é menor que o intervalo de cada burst, não se
identificaram transientes. Verificou-se também que, o aumento da
separação interburst degrada o desempenho do sistema.
20
Forsyth, Colin. "Bursty bulk flows and substorm-time magnetotail dynamics." Thesis, University of Leicester, 2009. http://hdl.handle.net/2381/4555.
Full textAbstract:
I present three studies of magnetospheric tail dynamics associated with bursty bulk flows (BBFs) and substorms, concentrating on observations of the current systems of the BBFs and the dynamics of magnetotail current sheet waves. From a case study, I show that the observed magnetospheric current system of a BBF consisting of two flow bursts matched the current system predicted by Sergeev et al. (1996), and that the currents were consistent with previous studies. I also show that the particle signatures of the BBF were similar to the particle signatures in the PSBL prior to the BBF observations, demonstrating that the BBF was produced by the reconnection of lobe magnetic field-lines. From a survey of 628 BBF events, I show that BBF occurrence is highest during the recovery phase of substorms and lowest during non-substorm times and substorm growth phases. Using a subset of 211 BBF encounters that were sufficiently far from the magnetotail current sheet to determine the field-aligned currents, I show that the current magnitude is larger during the expansion and recovery phases of substorms than during the growth phase. Furthermore, the current magnitude is larger in the pre-midnight sector on large scale sizes. Utilising data from ground- and space-based observatories, I investigate an interval of current sheet wave activity following a solar wind pressure pulse and two substorms. By comparing the propagation of aurora and tail dipolarization signatures and the neutral sheet waves, I conclude that the propagation of these features is controlled by the same mechanism. I test two models of neutral sheet wave propagation and find that the model of Erkaev et al. (2008) gives a good fit to the data.
21
Lundin, Erik. "Time and speed dependency of swimming bursts in guppies." Thesis, Uppsala universitet, Tillämpad matematik och statistik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-325583.
Full text
22
林敬偉 and King-wai Lam. "Time delay and broadening of gamma ray bursts in various energy bands." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1995. http://hub.hku.hk/bib/B31213200.
Full text
23
Lam, King-wai. "Time delay and broadening of gamma ray bursts in various energy bands /." Hong Kong : University of Hong Kong, 1995. http://sunzi.lib.hku.hk/hkuto/record.jsp?B14709041.
Full text
24
Chan, Ho-yin. "Simulation model for the time delay and broadening of gamma ray bursts /." Hong Kong : University of Hong Kong, 1995. http://sunzi.lib.hku.hk/hkuto/record.jsp?B14709107.
Full text
25
Heinrich, Aaron David. "Delayed neutrons from the neutron irradiation of ²³⁵U." Texas A&M University, 2008. http://hdl.handle.net/1969.1/85943.
Full textAbstract:
A series of experiments was performed with the Texas A&M University Nuclear
Science Center Reactor (NSCR) to verify ²³⁵U delayed neutron emission rates. A
custom device was created to accurately measure a sample's pneumatic flight time and
the Nuclear Science Center's (NSC's) pneumatic transfer system (PTS) was redesigned
to reduce a sample's pneumatic flight time from over 1,600 milliseconds to less than 450
milliseconds. Four saturation irradiations were performed at reactor powers of 100 and
200 kW for 300 seconds and one burst irradiation was performed using a $1.61 pulse
producing 19.11 MW-s of energy.
Experimental results agreed extremely well with those of Keepin. By comparing
the first ten seconds of collected data, the first saturation irradiation deviated ~1.869%
with a dead time of 2 microseconds, while the burst irradiation deviated ~0.303% with a
dead time of 5 microseconds. Saturation irradiations one, three and four were
normalized to the initial count rate of saturation irradiation two to determine the system
reproducibility, and deviated ~0.449%, ~0.343% and ~0.389%, respectively.
26
Jouret, Martine. "Conception et mise en oeuvre d'un systeme de detection et d'analyse des sursauts gamma, embarque sur le satellite granat." Toulouse 3, 1987. http://www.theses.fr/1987TOU30271.
Full textAbstract:
Description d'un systeme electronique, developpe dans le cadre du projet granat, charge de detecter des sursauts gamma et de determiner leurs caracteristiques temporelles et spectrales. Les donnees scientifiques, se rapportant aux sursauts sont acquises, traitees et formatees en temps reel
27
陳浩然 and Ho-yin Chan. "Simulation model for the time delay and broadening of gamma raybursts." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1995. http://hub.hku.hk/bib/B31212797.
Full text
28
Slotte, Tanja. "Evolution of Flowering Time in the Tetraploid Capsella bursa-pastoris (Brassicaceae)." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis Acta Universitatis Upsaliensis, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8311.
Full text
29
Buroni, Giovanni. "Near Real-Time Detection Of Pipe Bursts in Water Distribution Systems." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016.
Find full textAbstract:
The research work presented in the thesis describes a new methodology for the automated near real-time detection of pipe bursts in Water Distribution Systems (WDSs). The methodology analyses the pressure/flow data gathered by means of SCADA systems in order to extract useful informations that go beyond the simple and usual monitoring type activities and/or regulatory reporting , enabling the water company to proactively manage the WDSs sections.
The work has an interdisciplinary nature covering AI techniques and WDSs management processes such as data collection, manipulation and analysis for event detection. Indeed, the methodology makes use of (i) Artificial Neural Network (ANN) for the short-term forecasting of future pressure/flow signal values and (ii) Rule-based Model for bursts detection at sensor and district level.
The results of applying the new methodology to a District Metered Area in Emilia- Romagna’s region, Italy have also been reported in the thesis. The results gathered illustrate how the methodology is capable to detect the aforementioned failure events in fast and reliable manner.
The methodology guarantees the water companies to save water, energy, money and therefore enhance them to achieve higher levels of operational efficiency, a compliance with the current regulations and, last but not least, an improvement of customer service.
30
Di, Piano Ambra. "Detection of short Gamma-Ray Bursts with CTA through real-time analysis." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/19962/.
Full textAbstract:
With respect to the current IACTs, CTA will cover a larger energy range (~20 GeV - 300 TeV) with one order of magnitude better sensitivity. The facility will be provided with a real-time analysis (RTA) software that will automatically generate science alerts and analyse data from on-going observations in real-time. The RTA will play a key role in the search and follow-up of transients from external alerts (i.e. from on-space gamma-ray missions, observatories operating at other energy bands or targets of opportunity provided by neutrinos and gravitational waves detectors). The scope of this study was to investigate the ctools software package feasibility for the RTA, adopting a full-field of view maximum likelihood analysis method. A prototype for the RTA was developed, with natively implemented utilities where required. Its performance was extensively tested for very-short exposure times (far below the lower limit of current Cherenkov science) accounting for sensitivity degradation due to the non-optimal working condition expected of the RTA. The latest IRFs, provided by CTA Performance, were degraded via effective area reduction for this purpose. The reliability of the analysis methods was tested by means of the verification of Wilks' theorem. Through statistical studies on the pipeline parameter space (i.e. minimum required exposure time), the performance was evaluated in terms of localization precision, detection significance and detection rates at short-timescales using the latest available GRB afterglow templates for the source simulation. Future improvements involve further tests (i.e. with an updated population synthesis) as well as post-trials correction of the detection significance. Moreover, implementations allowing the pipeline to dynamically adapt to a range of science cases are required. Prospects of forthcoming collaboration may involve the integration of this pipeline within the on-going work of the gamma-ray bursts experts of CTA Consortium.
31
Deprez, Hannah. "Investigating the Time Evolution of X-Ray Absorption in Gamma-Ray Bursts." Thesis, KTH, Fysik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-277830.
Full text
32
Menšík, Jakub. "Zobrazování voxelových scén pomocí ray tracingu v reálném čase." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2021. http://www.nusl.cz/ntk/nusl-445579.
Full textAbstract:
The aim of this work was to create a program to visualize voxel scenes in real time using ray tracing. It included the study of various methods of such a rendering with a focus on shadows. The solution was created using Unity engine and experimental packages Unity Jobs and Burst. The thesis presents multiple ray tracing passes and SVGF technique, that is used to turn a noisy input into full edge-preserving image. The final program is able to render hard shadows, soft shadows, and ambient occlusion at speed of fifty frames per second.
33
Jedrzejczak, W. Wiktor, Jacek Smurzynski, and KatarzynaJ Blinowska. "Origin of Suppression of Otoacoustic Emissions Evoked by Two-Tone Bursts." Digital Commons @ East Tennessee State University, 2008. https://dc.etsu.edu/etsu-works/1990.
Full textAbstract:
Otoacoustic emission (OAE) data recorded for tone bursts presented separately and as a two-tone burst complex, that had been reported previously [Yoshikawa, H., Smurzynski, J., Probst R., 2000. Suppression of tone burst evoked otoacoustic emissions in relation to frequency separation. Hear. Res. 148, 95–106], were re-processed using the method of adaptive approximations by matching pursuit (MP). Two types of stimuli were applied to record tone burst OAEs (TBOAEs): (a) cosine-windowed tone bursts of 5-ms duration with center frequencies of 1, 1.5, 2 and 3kHz, (b) complex stimuli consisting of a digital addition of the 1-kHz tone burst together with either the 1.5-, 2- or 3-kHz tone burst. The MP method allowed decomposition of signals into waveforms of defined frequency, latency, time span, and amplitude. This approach provided a high time–frequency (t–f) resolution and identified patterns of resonance modes that were characteristic for TBOAEs recorded in each individual ear. Individual responses to single-tone bursts were processed off-line to form ‘sum of singles’ responses. The results confirmed linear superposition behavior for a frequency separation of two-tone bursts of 2kHz (the 1-kHz and 3-kHz condition). For the 1, 1.5-kHz condition, the MP results revealed the existence of closely positioned resonance modes associated with responses recorded individually with the stimuli differing in frequency by 500Hz. Then, the differences between t–f distributions calculated for dual (two-tone bursts) and sum-of-singles conditions exhibited mutual suppression of resonance modes common to both stimuli. The degree of attenuation depended on the individual pattern of characteristic resonance modes, i.e., suppression occurred when two resonant modes excited by both stimuli overlapped. It was postulated that the suppression observed in case of dual stimuli with closely-spaced components is due to mutual attenuation of the overlapping resonance modes.
34
Morgan, Adam Nolan. "Classification, Follow-Up, and Analysis of Gamma-Ray Bursts and their Early-Time Near-Infrared/Optical Afterglows." Thesis, University of California, Berkeley, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3739716.
Full textAbstract:
<p> In the study of astronomical transients, deriving knowledge from discovery is a multifaceted process that includes real-time classification to identify new events of interest, deep, multi-wavelength follow-up of individual events, and the global analysis of multi-event catalogs. Here we present a body of work encompassing each of these steps as applied to the study of gamma-ray bursts (GRBs). First, we present our work on utilizing machine-learning algorithms on early-time metrics from the <i>Swift</i> satellite to inform the resource allocation of follow-up telescopes in order to optimize time spent on high-redshift GRB candidates. Next, we show broadband observations and analysis of the early-time afterglow of GRB 120119A, utilizing data obtained with a dozen telescope facilities both in space and on the ground. This event exhibits extreme red-to-blue color change in the first few minutes after the trigger at levels unseen in prior afterglows, and our model fits of this phenomenon reveal the best support yet for the direct detection of dust destruction in the local environment of a GRB. Finally, we present results from the PAIRITEL early-time near-infrared (NIR) afterglow catalog. The 1.3 meter PAIRITEL has autonomously observed 14 GRBs in under 3 minutes after the burst, yielding a homogenous sample of early-time <i>JHK<sub>s</sub></i> light curves. Our analysis of these events provides constraints on the early-time NIR GRB afterglow luminosity function and gives insight into the importance of dust extinction in the suppression of some optical afterglows.</p>
35
Romano, Michele. "Near real-time detection and approximate location of pipe bursts and other events in water distribution systems." Thesis, University of Exeter, 2012. http://hdl.handle.net/10871/9862.
Full textAbstract:
The research work presented in this thesis describes the development and testing of a new data analysis methodology for the automated near real-time detection and approximate location of pipe bursts and other events which induce similar abnormal pressure/flow variations (e.g., unauthorised consumptions, equipment failures, etc.) in Water Distribution Systems (WDSs). This methodology makes synergistic use of several self-learning Artificial Intelligence (AI) and statistical/geostatistical techniques for the analysis of the stream of data (i.e., signals) collected and communicated on-line by the hydraulic sensors deployed in a WDS. These techniques include: (i) wavelets for the de-noising of the recorded pressure/flow signals, (ii) Artificial Neural Networks (ANNs) for the short-term forecasting of future pressure/flow signal values, (iii) Evolutionary Algorithms (EAs) for the selection of optimal ANN input structure and parameters sets, (iv) Statistical Process Control (SPC) techniques for the short and long term analysis of the burst/other event-induced pressure/flow variations, (v) Bayesian Inference Systems (BISs) for inferring the probability of a burst/other event occurrence and raising the detection alarms, and (vi) geostatistical techniques for determining the approximate location of a detected burst/other event. The results of applying the new methodology to the pressure/flow data from several District Metered Areas (DMAs) in the United Kingdom (UK) with real-life bursts/other events and simulated (i.e., engineered) burst events are also reported in this thesis. The results obtained illustrate that the developed methodology allowed detecting the aforementioned events in a fast and reliable manner and also successfully determining their approximate location within a DMA. The results obtained additionally show the potential of the methodology presented here to yield substantial improvements to the state-of-the-art in near real-time WDS incident management by enabling the water companies to save water, energy, money, achieve higher levels of operational efficiency and improve their customer service. The new data analysis methodology developed and tested as part of the research work presented in this thesis has been patented (International Application Number: PCT/GB2010/000961).
36
Holm, Karl. "Studies on Natural Variation and Evolution of Photoperiodism in Plants." Doctoral thesis, Uppsala universitet, Evolutionär funktionsgenomik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-119269.
Full textAbstract:
Photoperiodism refers to the organism’s ability to detect and respond to seasonal changes in the daily duration of light and dark and thus constitutes one of the most significant and complex examples of the interaction between the organism and its environment. This thesis attempts to describe the prevalence of variation in a photoperiodic response, its adaptive value, and its putative genetic basis in a common cruciferous weed, Capsella bursa-pastoris (Brassicaceae). Furthermore, the thesis presents a first comprehensive comparative overview of the circadian clock mechanism in an early land plant, Physcomitrella patens (Bryophyta), thus providing insights into the evolution of the plant circadian system. In an introductory survey of global gene expression changes among early- and late flowering accessions of C. bursa-pastoris we found an enrichment of genes involved in photoperiodic response and regulation of the circadian clock. Secondly, by phenotyping circadian rhythm variation in a worldwide sample of accessions with known flowering time, we detected robust latitudinal clines in flowering time and circadian period length, which constitute strong indications of local adaptation to photoperiod in the shaping of flowering time variation in this species. In an attempt to elucidate putative genetic causes for the correlated variation between circadian rhythm and flowering time, we found that sequence variation and diverged expression in components regulating light input to the clock, PHYTOCHROME B (PHYB) and DE-ETIOLATED 1 (DET1) make them strong candidate genes. Finally, we present a comparative study of circadian network topology in the moss P. patens. Phylogenetic analyses and time series expression studies of putative clock homologues indicated that several core clock genes present in vascular plants appeared to be lacking in the moss. Consequently, while the clock mechanism in higher plants constitutes at least a three-loop system of interacting components, the moss clock appears to comprise only a single loop. We conclude that C. bursa-pastoris is a highly suitable model system for the further elucidation of the molecular variation that influences adaptive change in natural plant populations. Furthermore, we believe that the continuing study of the seemingly less complex circadian network of P. patens not only can provide insights into the evolution of the plant circadian system, but also may help to clarify some of the remaining issues of the circadian clock mechanism in higher plants.
37
Puebla-Osorio, Nahum. "Transcriptional analysis of chicken immune cells following exposure to 2,3,7,8,-tetrachlorodibenzo-p-dioxin (TCDD)." Texas A&M University, 2004. http://hdl.handle.net/1969.1/3165.
Full textAbstract:
In the present investigation, microarray analysis was used to identify potential TCDD gene targets. Three microarray experiments were performed to study the effect of TCDD in an established chicken B-cell line (DT40), in a chicken macrophage cell line (HD11), and in the bursa of Fabricius from embryos exposed in ovo at 6 days of incubation. From the DT40 microarray analyses, clones with sequence similarity to the apoptotic genes caspase 8 and caspase 9, and the transcription factor NFΜB, among others, were identified. Real-time quantitative polymerase chain reaction (RT-PCR) revealed that TCDD elicits aryl hydrocarbon receptor (AhR)-mediated apoptosis in the avian DT40 pre-B-cell line through activation of caspases 9 and 3 (see chapter III). During the course of the HD11 microarray analyses, a consistent down-regulation of the matrix metalloprotease MMP-2 was observed. This finding was the basis for the hypothesis that TCDD has an effect on the gene expression of the MMP-2 and MMP-9 in macrophages. Then, gene expression analysis and functional zymography showed that TCDD impairs the MMP-2 and MMP-9 response to LPS stimulation in HD11 chicken macrophages (see chapter V). The microarray analyses of the embryonic bursa of Fabricius provided the basis to further study of the effect of TCDD in the chicken embryo. The shifted genes were classified according to their function. The down-regulated genes included: precursor of matrix metalloprotease-inhibitor, histone acyl-transferase 1, homeobox protein CUX-2, Death Associated Protein Kinase, and UDPglucosyl transferase, among others. The up-regulated genes included: phosphoinositidespecific phospholipase, acyl Co-A oxidase, and protein effector of Cdc42, among others.
Together, these microarray analyses produced a database of genes of interest that will provide sufficient hypotheses to inspire multiple investigations aimed at confirming and refining the gene expression alterations as a consequence of TCDD exposure.
38
Yu, Hoi Fung Verfasser], Jochen [Akademischer Betreuer] [Greiner, and Elisa [Akademischer Betreuer] Resconi. "Constraints on the Prompt Emission Mechanism of Gamma-Ray Bursts using Time-Resolved Spectroscopy / Hoi Fung Yu. Betreuer: Jochen Greiner. Gutachter: Jochen Greiner ; Elisa Resconi." München : Universitätsbibliothek der TU München, 2016. http://d-nb.info/1085018466/34.
Full text
39
Mickael, Claudia Silva. "Real-time RT-PCR analysis of two epitope regions encoded by the VP2 gene of infectious bursal disease viruses." Connect to this title online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1116532082.
Full textAbstract:
Thesis (Ph. D.)--Ohio State University, 2005.<br>Title from first page of PDF file. Document formatted into pages; contains xiii, 136 p.; also includes graphics (some col.) Includes bibliographical references (p. 120-136). Available online via OhioLINK's ETD Center
40
Antier-Farfar, Sarah. "La détection des sursauts gamma par le télescope ECLAIRs pour la mission spatiale SVOM." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS467/document.
Full textAbstract:
Les sursauts gamma sont des événements fascinants de par leur origine longtemps restée mystérieuse, leur apparition imprévisible dans le ciel, et la formidable énergie qu'ils libèrent sous forme de bouffées de rayonnement gamma. Découverts fortuitement au début des années 1970, ils se traduisent par un intense flash de rayons gamma de brève durée (de quelques ms à quelques min), appelé émission prompte, suivi d'une émission longue, appelée rémanence, qui décroît rapidement, en émettant depuis les rayons X jusqu'au domaine radio. L'origine des sursauts gamma est encore largement discutée mais ces phénomènes extrêmes sont très vraisemblablement associés à la formation de nouveaux trous noirs stellaires. Mon sujet de thèse se situe au coeur de la mission sino-française SVOM dont le lancement du satellite est prévu en 2021, qui scrutera le ciel pour observer les sursauts avec une précision inégalée, associant observations spatiales et terrestres. Mon travail concerne l'instrument principal de la mission, le télescope spatial ECLAIRs. Il s'agit d'une caméra à masque codé sensible aux rayons X et gamma de basse énergie, en charge de la détection et de la localisation de l'émission prompte des sursauts. Durant mon travail de thèse, j'ai travaillé sur les performances scientifiques de l'instrument ECLAIRs et j'ai en particulier estimé le nombre de sursauts qui seront détectés et leurs caractéristiques. Pour cela, j'ai mis en place des simulations de performances utilisant les prototypes des algorithmes de détection embarqués combinés au modèle de l'instrument ECLAIRs. Les données en entrée des simulations comportent un bruit de fond simulé, et une population synthétique de sursauts gamma générée à partir de catalogues existants issus des observations des missions antérieures (CGRO, HETE-2, Swift et Fermi). Mon étude a permis d'estimer finement l'efficacité de détection d'ECLAIRs et prédit un taux de sursauts attendu par ECLAIRs entre 40 et 70 sursauts par an. Par ailleurs, mon travail a montré qu'ECLAIRs sera particulièrement sensible à une population de sursauts très riches en rayons X, population encore mal connue. Ma thèse présente plusieurs autres études complémentaires portant sur la performance de localisation, le taux de fausses alertes et les caractéristiques des déclenchements des algorithmes. Enfin, j'ai proposé deux nouvelles méthodes originales de détection de sursauts dont les résultats préliminaires présentés dans ma thèse sont très encourageants. Ils montrent que la sensibilité d'ECLAIRs aux sursauts courts (population d'intérêt particulier en raison de son lien attendu avec les ondes gravitationnelles) peut être encore améliorée<br>Discovered in the early 1970s, gamma-ray bursts (GRBs) are amazing cosmic phenomena appearing randomly on the sky and releasing large amounts of energy mainly through gamma-ray emission. Although their origin is still under debate, they are believed to be produced by some of the most violent explosions in the Universe leading to the formation of stellar black-holes. GRBs are detected by their prompt emission, an intense short burst of gamma-rays (from a few millisecondes to few minutes), and are followed by a lived-afterglow emission observed on longer timescales from the X-ray to the radio domain. My thesis participates to the developement of the SVOM mission, which a Chinese-French mission to be launched in 2021, devoted to the study of GRBs and involving space and ground instruments. My work is focussed on the main instrument ECLAIRs, a hard X-ray coded mask imaging camera, in charge of the near real-time detection and localization of the prompt emission of GRBs. During my thesis, I studied the scientific performances of ECLAIRs and in particular the number of GRBs expected to be detected by ECLAIRs and their characteristics. For this purpose, I performed simulations using the prototypes of the embedded trigger algorithms combined with the model of the ECLAIRs instrument. The input data of the simulations include a background model and a synthetic population of gamma-ray bursts generated from existing catalogs (CGRO, HETE-2, Fermi and Swift). As a result, I estimated precisely the ECLAIRs detection efficiency of the algorithms and I predicted the number of GRBs to be detected by ECLAIRs : 40 to 70 GRBs per year. Moreover, the study highlighted that ECLAIRs will be particularly sensitive to the X-ray rich GRB population. My thesis provided additional studies about the localization performance, the rate of false alarm and the characteristics of the triggers of the algorithms. Finally, I also proposed two new methods for the detection of GRBs.The preliminary results were very promising and demonstrate that the sensitivity of ECLAIRs to the short GRBs (an interesting population due to the predicted association with gravitational waves) could be improved further
41
Bajat, Armelle. "Etude des réponses temporelle et spectrale de l'instrument ECLAIRs pour la mission SVOM." Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30151/document.
Full textAbstract:
La mission Franco-chinoise SVOM (Space based multi-band Variable astronomical Object Monitor), est dédiée à l'étude des sursauts ƴ, intenses et brèves bouffées de photons en X et ƴ, associées à la formation catastrophique de trous noirs. SVOM embarquera en 2021 quatre instruments observant du visible jusqu'aux rayonnements ƴ. ECLAIRs, télescope principal, est une caméra à masque codé capable de détecter et localiser, environ 200 sursauts pendant les trois années de vie de la mission. Son plan de détection compte 6400 détecteurs CdTe à contact Schottky, qui sont regroupés en matrice de 32 formant un module. Le plan est divisé en huit secteurs électroniquement indépendants, composés chacun de 25 modules. Chaque électronique est dédiée à la lecture et au codage du temps, de la position, de la multiplicité et des énergies des événements détectés sur un secteur. La validation des fonctionnalités de l'électronique de lecture a permis de s'assurer du bon codage des événements, d'estimer les limites de l'électronique et de construire un modèle analytique de correction efficace des événements perdus. Une application à une courbe de lumière d'un sursaut brillant a permis de valider théoriquement ce modèle et des mesures réalisées sur le prototype ont permis de le valider expérimentalement. D'autre part, un modèle complet de la réponse spectrale a été construit afin de caractériser chaque détecteur pavant le secteur du prototype et d'estimer la réponse du plan de détection des photons mono-énergétiques. Les processus physiques des interactions rayonnement-matière ont été simulés ainsi qu'un modèle de perte de charges puis une convolution gaussienne permet de considérer le bruit électronique. Ce modèle, comptant six paramètres libres, est ajusté à des spectres réalisés sur le prototype. L'étude des paramètres extraits caractérise les performances de chaque détecteur dans toutes les configurations de tension et de t peaking et permet d'optimiser les performances de l'instrument<br>The french-chinese mission SVOM (Space-based multi-band variable Astronomical Object Monitor), is dedicated to the study of ƴ-rays bursts, brief and intense X and ƴ photons flashes, associated with the catastrophic formation of black holes. SVOM will embark in 2021 four instruments observing from the visible to ƴ rays. ECLAIRs, the main telescope, is a coded mask camera able to detect and locate, about 200 bursts during the three years nominal life time of SVOM. Its detection plan counts 6400 Schottky CdTe detectors, grouped into a matrix of 32 pixels forming a module. The plan is divided into eight electronically independent sectors, each consisting of 25 modules. Each electronic is dedicated to read and encode, the time, the position, the multiplicity and the energies of the detected events on a sector. The validation of each functionality of the readout electronics allows to ensure the correct encoding of the events, to estimate the limits of the electronics and to build an analytical model of lost events efficient correction. An application to a lightcurve of a bright GRB permits to validate theoretically this model and measurements carried out on the prototype validates it experimentally. On the other hand, a complete model of the spectral response has been established to characterize each detector on the sector of the prototype and to estimate the response of the plan of detection of the mono-energetic photons. The physical processes of the radiation-matter interactions are simulated as well as a model of lost charges then a Gaussian convolution takes into account the electronic noise. This model, counting six free parameters, is fitted to spectra measured on the prototype. The study of the extracted parameters characterizes the performance of each detector in every voltage and t peaking configurations optimizing the performance of the instrument
42
Jalia, Aftab. "Innovative masonry shell construction in India's evolving building crafts : a case for tile vaulting." Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/271686.
Full textAbstract:
This thesis uses the lens of building technology to examine cultural exchange and its relationship to the building crafts. By focusing on masonry vaulting in India, my research brings together two worlds – one that shines light on the variety of innovative masonry shell construction techniques that exist in the county and another that seeks to evaluate the scope of tile vaulting, an over 600-year old Mediterranean building technique, within India’s evolving building crafts culture. This thesis is organized in three parts: PART ONE Tile Vaulting and Relevance Today | A Brief History of Masonry Shells in India Part one introduces tile vaulting’s unique principles compared to other vaulting traditions while contextualizing its relevance to present day India. A survey of varied masonry vaulting techniques and modules, endemic and imported, practiced across India is presented against the backdrop of what is a predominantly reinforced concrete-based construction industry. PART TWO Modules, Methods and Motivations The second part of this research comprises case studies that include some of India’s most iconic buildings such as the Villa Sarabhai by Le Corbusier, the National Institute of Design by Gautam Sarabhai and Sangath by B.V. Doshi, each of which employed innovative construction techniques for its vaults. The production and use of the enigmatic ceramic fuses in India is examined for the first time alongside their indigenous cousins: burnt clay tubes. Together with Muzaffarnagar vaulting, the case studies reveal cultural motivations for architectural expression and production in postcolonial India. PART THREE Prototypes | Comparatives | Limitations & Extension of Research Part three presents five tile vaulting prototypes in India constructed with local artisans to gain understanding of its cultural reception, assess effective transfer of skills and potential internalisation. Recommendations for tile vaulting’s potential uptake into mainstream architectural production is evaluated by comparing findings against prevalent building methods and by contextualizing current architectural trends and social policy. Limitations and scope for extension of research are also discussed.
43
Ben, Sassi Marwen. "Contribution à la mesure temporelle et à la simulation en équilibrage harmonique de la stabilité d’impulsion à impulsion de transistors en technologie GaN." Thesis, Limoges, 2021. http://www.theses.fr/2021LIMO0018.
Full textAbstract:
Ce travail de thèse a permis de décrire, pour la première fois à notre connaissance, une comparaison des performances Pulse à Pulse (P2P) d'un HEMTAlGaN/GaN obtenue, expérimentalement d'une part grâce à un système de caractérisation entièrement étalonné et d'autre part, grâce à une simulation Harmonic Balance (HB) 2tons d'un modèle fonderie du transistor. Les mesures et les simulations HB permettent l'extraction simultanée et cohérente, d'une part, des enveloppes complexes des tensions et courants hyperfréquences (RF) et, d'autre part, du courant de drain Basse Fréquence (BF) généré par les non-linéarités des composants mesurés ou de leurs modèles électrothermiques simulés. Les enveloppes complexes de tension et de courant aux deux ports des dispositifs sous test (DST) et de la tension et du courant (BF) de drain ont été simultanément mesurées/simulées avec une rafale radar irrégulière périodique composée d'impulsions transitoires ultra courtes et en utilisant les mêmes rafales radar dont, la largeur d’impulsion t et les temps de montée/descente ont été modifiés. L’originalité majeure de ce travail réside dans le fait que les formes d'onde RF générées dans le domaine temporel utilisées par les sources du banc de test ou celles des simulation sont été corrigées pour réduire considérablement les phénomènes de Gibbs.Les facteurs de Lanczos/Fejér ont été implémentés dans des simulateurs. En revanche, à notre connaissance, c'est la première fois qu'ils sont directement utilisés pour générer un signal utile dans un système de caractérisation micro-ondes et dans une simulation HB 2tons<br>This work describes, for the first time to our knowledge, a comparison of Pulse to Pulse (P2P) stabilities of an AlGaN/GaN HEMT experimentally extracted thanks to an on-wafer fully calibrated characterization system and on the other hand, from a Harmonic Balance (HB) two-tone simulation of a foundry-based model of the transistor. For the first time, Lanczos and Fejér factors are experimentally implemented in the time-domain characterization system in order to reduce the Gibbs phenomen on effects and to perform causal measurements.Thanks to these two tools, the complex envelopes of the microwave (RF) voltages and currents and the Low-Frequency (LF) drain current have been measured/simulated. The complex RF voltage/current envelopes at both ports of the DUT and the LF drain voltage/current have been simultaneously measured/simulated using a periodic irregular radar burst.The P2P stability criterion has been calculated, in this work, using two mathematical expressions (RMS/ET).These two methods are based on the use of the amplitude/phase or the real/imaginary of the measured/simulated (HB 2tone) complex envelopes of the RF output voltage. Ultra-short transient pulses(13ns) have been used. Simulation preliminary results are processing. They will constitute a solid preparation for the future work
44
Lacombe, Karine. "Réalisation de grands plans de détection pixélisés pour l'astronomie gamma : contribution à l'étude et à la réalisation du module XRDPIX pour l'instrument ECLAIRs sur la mission spatiale SVOM." Thesis, Toulouse 3, 2019. http://www.theses.fr/2019TOU30326.
Full textAbstract:
ECLAIRs, l'imageur à rayons X dur de la mission sino-française SVOM, est dédié à la détection et à la localisation en quasi temps réel de sources transitoires cosmiques dans la plage d'énergie allant de 4 à 150 keV. Cet instrument est une caméra grand champ, munie d'un plan de détection pavé de 6400 détecteurs Schottky CdTe, qui permet de créer des images du ciel en rayons X durs grâce à un système de localisation appelé " masque codé ". Les travaux exposés dans ce manuscrit détaillent la conception, la réalisation et la mesure des performances de modules hybrides de 32 détecteurs lus par un ASIC (appelés modules XRDPIX), qui constituent les briques de base du plan de détection, et qui permettent d'atteindre des performances inégalées pour ce type d'instrument avec un seuil en énergie égal à 4 keV. Après avoir posé la problématique de détection des sources cosmiques transitoires en rayons X, en s'appuyant sur le contexte astrophysique de la mission SVOM, puis détaillé son instrument principal, j'expose, dans ce mémoire de thèse, mon travail sur la réalisation de grands plans de détection pixélisés pour l'astronomie gamma, avec en particulier ma contribution à l'étude et à la réalisation du module XRDPIX. Le développement des modules XRDPIX, fait appel à la fois à une conception faible bruit et à l'utilisation de technologies innovantes. Les détecteurs CdTe sont polarisés jusqu'à -450V et régulés à basse température (nominalement 20°C) afin de minimiser le courant de fuite et de limiter les effets de polarisation. Le seuil bas en énergie requis pour la mission spatiale est atteint grâce à une caractérisation approfondie des éléments constituant les 200 XRDPIX de vol, qui forment la caméra ECLAIRs. Je présente de façon détaillée les caractéristiques physiques et technologiques de ces modules, les différentes étapes de leur développement, en justifiant les solutions et les compromis techniques qui ont jalonné leur fabrication. Ensuite, en me basant sur un échantillon statistique abondant, obtenu lors des nombreux tests et qualifications réalisés sur plusieurs centaines de modules et sous-modules, j'expose les résultats de mesures qui démontrent les excellentes performances du module XRDPIX, en termes de résolution spectrale, de seuil bas en énergie, de gain et de comptage. Des études annexes sont également montrées, afin de compléter la validation des XRDPIX par l'analyse de l'influence de divers paramètres physiques sur les performances, comme par exemple la température. En conclusion, grâce à ces analyses de données abondantes, et à des modélisations du bruit total équivalent, je propose des réglages optimaux pour deux paramètres de configuration clés : la valeur de polarisation pour la haute tension et le peaking time, qui permettent d'obtenir le seuil en énergie de 4 keV exigé par la mission SVOM, avec une bonne uniformité sur l'ensemble du plan de détection. Finalement, je présente ce retour d'expérience, couplé à l'étude des paramètres clés qui déterminent la sensibilité d'un imageur grand champ dans le domaine des X durs (surface de détection, gamme d'énergie, champ de vue, ...), ce qui m'amène à proposer des pistes pour la réalisation d'instruments ambitieux avec des gains en sensibilité significatifs dans le futur<br>ECLAIRs, the hard X-ray imager of the Chinese-French SVOM mission, is dedicated to the detection and localization in near real-time of cosmic transient sources in the energy range from 4 to 150 keV. This instrument is a wide field camera, equipped with a detection plane paved with 6400 CdTe Schottky detectors, which allows to create hard X-ray images of the sky thanks to a localization system called "coded mask". The work presented in this manuscript details the design, the realization and the measurement of the performances of hybrid modules of 32 detectors read by an ASIC (called XRDPIX modules), which constitute the basic bricks of the detection plan, and which make it possible to reach unequalled performances for this type of instrument with a threshold in energy equal to 4 keV. After having posed the problem of detection of transient cosmic sources in X-rays, based on the astrophysical context of the SVOM mission, and then detailed its main instrument, I present, in this thesis, my work on the realization of large pixelated detection plans for gamma-ray astronomy, with in particular my contribution to the study and the realization of the XRDPIX module. The development of the XRDPIX modules, calls for both a low noise design and the use of innovative technologies. The CdTe detectors are biased down to -450V and regulated at low temperature (nominally 20°C) in order to minimize the leakage current and to limit the polarization effects. The low energy threshold required for the space mission is reached thanks to a thorough characterization of the elements constituting the 200 flight XRDPIX, which form the ECLAIRs camera. I present in detail the physical and technological characteristics of these modules, the various stages of their development, justifying the solutions and technical compromises that have marked their manufacture. Then, based on an abundant statistical sample, obtained during the numerous tests and qualifications carried out on several hundreds of modules and sub-modules, I present the results of measurements which demonstrate the excellent performances of the XRDPIX module, in terms of spectral resolution, low energy threshold, gain and counting. Additional studies are also shown, in order to complete the validation of the XRDPIX by analyzing the influence of various physical parameters on the performances, such as temperature. In conclusion, thanks to these abundant data analyses, and to models of the total equivalent noise, I propose optimal settings for two key configuration parameters: the bias value for the high voltage and the peaking time, which allow to obtain the 4 keV energy threshold required by the SVOM mission, with a good uniformity on the whole detection plane. Finally, I present this feedback, coupled with the study of the key parameters that determine the sensitivity of a wide field imager in the hard X-ray domain (detection area, energy range, field of view, ...), which leads me to propose avenues for the realization of ambitious instruments with significant gains in sensitivity in the future
45
Wan, Been-Lih, and 萬本立. "Real-time Flood Forecasting by Considering the Rain-burst Effect." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/14111022041155049899.
Full textAbstract:
碩士<br>國立臺灣大學<br>生物環境系統工程學研究所<br>100<br>In recent years, the extreme rainfall events become more and more so that result in many flood disasters that make residents’ lives and property suffered a serious threat. In order to reduce flood damage, real-time flood forecasting has become an important research topic.
Research analysis was processed with flood events of Tseng-Wen Reservoir Watershed and Chi-Lan River basin. This study constituted several forecasting models of hourly stream discharge based on AR(2) model and Naïve model, and correct the problem of forecasting time lag phenomenon by considering rainfall data.
The discussion of rainfall data is divided in two parts. First part is that discuss the relationship between increment of rainfall and increment of discharge. By identify the increment of rainfall (rain-burst) which can make discharge significantly increase in a short time, we can establish the function of relationship between increment of rainfall and increment of discharge and combined with AR(2) model to correct the problem of forecasting time lag phenomenon which result from rain-burst effect. Second part is that apply the concept of unit hydrograph to establish response function between rainfall difference and discharge difference by linear regression, use data of rainfall difference before prediction time to estimate discharge difference on prediction time and combined with Naïve model to forecast hourly discharge. By considering the trend of rainfall variations, significantly improve the problem of forecasting time lag phenomenon.
The results of research shows that AR(2) model by considering the rain-burst effect can improve the problem of forecasting time lag phenomenon and enhance CP value by reducing the prediction error on peak time. And the performance of Naïve model which combined with response function is significantly better than other models. This result demonstrates that considering the trend of rainfall variations is very effective to improve the problem of forecasting time lag phenomenon.
46
jin, yuh-chuan, and 金郁川. "a new symbol time synchronization technique for short-burst TDM transmissions." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/09587688742791529558.
Full textAbstract:
碩士<br>國立中正大學<br>電機工程學系<br>85<br>Two key elements in the design of a demodulator are symbol time
synchronization and offset frequency synchronization. PACS(
Personal Access Communication Service)is a low-power microcell
mobile phone system proposed by Bellcore. This system features
short-burst TDM transmission at 1.8 GHz. Bellcore has proposed
a method of implementing the PACS demodulator which has been
patented. The Bellcore method obtains (1) symbol
synchronization, (2) an estimate of the offset frequency,and (3)
the quality measure, i.e., an estimate of the channel(path)
quality simultaneouslyafter a predetermined set of computation.
We develop a new method which obtainsa symbol time
synchronization and a frequency offset estimation through
separatecalculations, whith symbol time estimation preceeding
frequency offset synchronization.However the total of the two
calculation does not exceed the one data burst limit.
Furthermore, the amount of computation in this new method is
comparable to that Bellcore method. This thesis addresses
the problem of symbol time synchronization for a PACSmodem. A
prefilter-square-DFT combination was able to determine the
proper sampingpoint within 30 symbols. This, in conjunction
with the 30 symbol periods required for the frequency offset
estimation algorithm, is able to complete the time and freuency
synchronization within one burst of 64 symbols, as required by
the PACS specifications. Analysis, computer simulation results
and hardware architectureare presented.
47
Martins, João Manuel Carrilho Gil. "Time-Interleaved Block Windowed Burst OFDM: Channel Estimation and Synchronization techniques." Master's thesis, 2020. http://hdl.handle.net/10316/92199.
Full textAbstract:
Dissertação de Mestrado Integrado em Engenharia Electrotécnica e de Computadores apresentada à Faculdade de Ciências e Tecnologia<br>No contexto da indústria de telecomunicações, as comunicações móveis desempenham um papel muito importante devido ao seu impacto na economia e na sociedade global. As expectativas aumentam com a introdução da quinta geração (5G) que permite o acesso dos utilizadores em qualquer lugar com elevada fiabilidade e qualidade de serviço.Dentro deste contexto, é usado o Orthogonal Frequency Division Multiplexing (OFDM) que garante robustez contra canais seletivos no domínio da frequência, fornece elevadas taxas de transmissão de dados e fácil implementação baseada na transformada discreta de Fourier.No entanto, esta técnica apresenta uma eficiência espectral limitada, baixa eficiência energética e sensibilidade a erros de sincronismo.Como alternativa, foram desenvolvidas técnicas de modulação híbridas, como o Time Interleaved Block Windowed Burst-OFDM (TIBWB-OFDM).Esta dissertação desenvolve o modelo do transceptor TIBWB-OFDM através da introdução de técnicas adequadas a um cenário de comunicações reais sem fios. Consequentemente, os principais desafios e foco deste trabalho passaram pelo desenvolvimento de algoritmos de estimação de canal e sincronismo de tramas. Um passo importante para obter uma sincronização de tramas fiável é a escolha de preâmbulos com propriedades de correlação ótimas, como por exemplo, as sequências de Zadoff-Chu (ZC). Os resultados experimentais mostram que aplicando algoritmos de correlação e um dispositivo de limiar, é possível detectar perfeitamente o ínicio de cada trama TIBWB-OFDM. Em simultâneo, as sequências de ZC foram também aplicadas no contexto de estimação de canal através da aplicação de estimadores e algoritmos desenvolvidos baseados no OFDM.Desta forma, esta dissertação propõe um método conjunto de estimação de canal e sincronismo de tramas, aplicado ao TIBWB-OFDM, tomando partido das sequências ZC amplificadas.<br>In the segment of communications industry, wireless mobile communications are one of the most important innovations of our times due to its impact in the global economy and society. Expectations grow with the arrival and demands that the fifth generation of mobile telecommunications (5G) brings associated with an everywhere user access with better reliability and quality. In this context, Orthogonal Frequency Division Multiplexing (OFDM) is a widely used system that guarantees robustness against frequency selectivity channels, provide high data transmission rates and a easy implementation based on the discrete Fourier transform. However, this technique has high limited spectral efficiency, low power efficiency and sen- sitivity to synchronization errors. As an alternative, hybrid modulation techniques such as the time interleaved block windowed burst orthogonal frequency division multiplexing (TIBWB-OFDM) were developed.This thesis develops the TIBWB-OFDM transceiver model and the modifications necessary to implement this technique in a real wireless link scenarios. Hence, channel estimation and frame synchronization algorithms were the key challenges and focus of this work. An important step to achieve reliable frame synchronization is the choice of preamble sequences with optimum correlation proprieties, such as the Zadoff-Chu (ZC) sequences. Our experimental results show that by applying a correlation algorithm and a threshold device it is possible to detect perfectly each TIBWB-OFDM frame beginning. On the other hand, ZC sequences were also used to acquire the channel information by applying estimators and algorithms based on the OFDM technique.Therefore, this thesis proposes a joint channel and frame synchronization esti- mation using power amplified ZC sequences as preambles in the TIBWB-OFDM method.
48
Kuo, Liang-Wei, and 郭良偉. "Detection Technology for Time Division Multiple Access Burst Signals in Satellites." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/czmsr4.
Full textAbstract:
碩士<br>國立中央大學<br>資訊工程學系在職專班<br>106<br>The use of time division multiple access as a burst communication method can improve the efficiency of frequency allocation in limited-frequency bands. However, the weak energy of satellite signals and the bursting feature of burst signals are prone to engender data errors or loss. Such conditions increase incidence levels of communication errors and cause delays in communication. Therefore, this study designed an algorithm for burst-signal detection that integrates multiple methods, such as the F-test, energy detection, and matched filters. In the proposed algorithm, measures of moving average and F-test are implemented on two adjacent signal frames to obtain the similarity of the signals between two adjacent time points, thereby determining whether the signals are changing drastically. The results are then used to predict the starting point of the burst. Subsequently, the maximum value within the prediction time is identified using energy detection and matched-filter detection to acquire the precise opening time of the burst. The experiment presented in this paper was carried out under normal conditions in an environment with strong background noise and with pulsed interference for verification. The detection rate and accuracy rate for the proposed method were more favorable than those for general detection methods, indicating that the proposed algorithm may be used to enhance the quality and stability of burst communications, thereby preventing communication errors and delays.
49
"Offset time-emulated architecture for optical burst switching-modelling and performance evaluation." Universitat Politècnica de Catalunya, 2008. http://www.tesisenxarxa.net/TDX-0416108-110440/.
Full text
50
HSU, HSIANG-LI, and 徐祥理. "A Study of Burst Risk Assessment in Real-time Stocks Trading Volume." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/6n67f8.
Full textAbstract:
碩士<br>國立雲林科技大學<br>資訊管理系<br>106<br>Most people want to increase their income by investing because of the current economic downturn, and the high remuneration of stocks has become a factor that attracts most investors. However, there are many factors affecting the trading volume and trading price fluctuations in the stock market. Therefore, every investor hopes to reduce investment risks by measuring tools. The prediction of stock trading price is one of the most important issues in financial markets. Financial time series forecasting is a popular application of machine learning methods. Previous research reports indicate that advanced forecasting methods can highly accurately predict changes in trading prices in financial markets, and can also use these forecasting results to make profits. This study intends to use the instant flow data processing architecture in the Spark framework. The real-time stock trading volume is calculated according to the trading volume burst static and dynamic comprehensive index B_SD (i,j), and then the risk notification is sent according to different trading volume levels through the stock trading volume risk rating standard. Enables investors to quickly receive the sudden timing of real-time stock trading volume, allowing investors to choose the best time to invest. The research results of this study show that investors wanting to operate high-risk stock market can be judged by the stock trading volume risk rating standard, and the real stock trading volume should be sold immediately according to the pessimist operating strategy. The opportunity to make a profit will increase after the closing of the next day or the next five days.