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1
Abdulazeez, Abdulhakeem. "Development of an autonomous control protocol for a UAV fleet network using machine learning". Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPASG107.
Testo completoAbstract (sommario):
Dans le contexte de la robotique en réseau sans fil, des missions complexes, telles que la recherche et le sauvetage autonomes, peuvent nécessiter l’utilisation de plusieurs véhicules aériens sans pilote (UAV) déployés en formation afin d’augmenter l’efficacité et la qualité de service (QoS) tout en garantissant des impératifs spécifiques à la mission, tels que la maximisation de la couverture d’une zone en un seul passage de la flotte sur des sous-sections de celle-ci. Pour relever ces défis, un protocole efficace de localisation et de contrôle de formation est nécessaire.Les solutions existantes proposées pour la localisation à faible coût des UAV utilisant les valeurs de l’indicateur de puissance du signal reçu (RSSI) ont été conçues pour des environnements intérieurs, en réponse à la limitation du Global Navigation Satellite System (GNSS) en intérieur, ce qui les rend inapplicables aux environnements extérieurs.Celles développées pour fonctionner en extérieur sont soit inadaptées aux nœuds mobiles, soit inapplicables aux dispositifs aériens déployés dans des environnements complexes avec des effets de propagation variables. De plus, les protocoles de contrôle existants spécifiquement conçus pour le contrôle autonome des flottes de drones ne tiennent pas compte de l’orientation de la formation.Afin de couvrir ces aspects, cette thèse propose un protocole de contrôle de formation basé sur l’apprentissage, comprenant trois mécanismes de contrôle pour aborder les questions d’estimation de distance en extérieur, d’adaptation de la vitesse et d’orientation de la formation. Le protocole adapte le principe d’apprentissage par renforcement multi-agents (MARL) pour autopiloter la structure leader-suiveur de la flotte de drones en utilisant uniquement les valeurs RSSI reçues par les UAV lors des communications sans fil avec leursvoisins. Les suiveurs doivent suivre le leader tout en maintenant la structure leader-suiveur préconfigurée de manière autonome. Tout d’abord, un estimateur de distance basé sur un réseau de neurones profonds (DNN) utilisant le RSSI a été développé pour fournir des estimations plus précises de la distance entre n’importe quelle paire d’UAV en formation afin d’améliorer la localisation. L’estimateur a été entraîné à l’aide d’un ensemble de données collectées par simulation pour diverses configurations de formation en termes de vitesse, d’altitude, de tailles de formation et de modèles de perte de propagation. Le deuxième protocole traite du problème de l’adaptation de la vitesse en utilisant le principe basé sur le MARL, intégrant l’estimateur de distance basé sur le RSSI pour le calcul des distances. Les suiveurs sont formés par l’expérience collective de l’environnement pour ajuster leur vitesse de manière autonome par rapport à celle du leader lors d’un mouvement linéaire. Pour résoudre le problème d’alignement de l’orientation, un protocole de détection de direction et d’alignement de formation a été développé en utilisant le principe basé sur le MARL. Comme l’adaptateur de vitesse, ce protocole intègre également l’estimateur de distance. Les drones suiveurs sont entraînés à détecter la direction de vol du leader et à tourner comme un corps rigide autour de l’axe de lacet pour se réaligner sur le leader. Nous avons implémenté le protocole en utilisant NS3-3.35 intégré à la bibliothèque d’apprentissage automatique mlpack et évalué ses performances à travers plusieurs essais expérimentaux. Les résultats démontrent que le protocole atteint de meilleures performances en termes d’erreur estimée de distance tolérable, de stabilité de formation, d’erreur de déviation de formation et de temps de réponse accruIn the context of wireless networked robotics, complex missions, such as autonomous search and rescue may require the use of multiple Unmanned Aerial Vehicles (UAVs) deployed as a formation to achieve higher efficiency and Quality of Service (QoS) while assuring mission-specific imperatives like the maximization of area covered in a single passage of the fleet over area subsections. Addressing these challenges requires an efficient localization and formation control protocol.Existing solutions proposed for low-cost localization of UAVs using Received Signal Strength Indicator (RSSI) values, were designed for indoor environments in response to the limitation of Global Navigation Satellite System (GNSS) indoors, making them not applicable to outdoor environments.Those developed to work outdoors are either unsuitable for mobile nodes or not applicable for aerial devices deployed in complex environments with varying propagation effects. Also, existing control protocols designed specifically for autonomous control of UAV-fleet do not consider the formation orientation. To cover these areas, this thesis presents an efficient learning-based formation control protocol consisting of three control mechanism to address the issue of outdoor distance estimation, speed adaptation, and formation orientation. The protocol adapts the Multi-Agent Reinforcement Learning (MARL) principle to autopilot the UAV fleet leader-follower structure using only RSSI values the UAVs receive during wireless communication with their neighbors. The followersare expected to follow the leader while maintaining the pre-configured formation leader-follower structure autonomously. First, a DNN RSSI-based distance estimator was developed to provide more accurate estimates of the distance between any pair of UAVs in formation for better localization. The estimator was trained using a dataset collected through simulation for varying formation configurations in terms of speed, altitude, formation sizes, and propagation loss models. The second protocol addresses the issue of speed adaptation using the MARL-based principle, incorporating the RSSI-based distance estimator for ranging. The followers are trained through the collective experience of the environment to autonomously adjust their speed relative to that of the leader during a linear movement.To address the orientation alignment problem, a direction detection and formation alignment protocol was developed using the MARL-based principle. Like the speed adapter, this protocol also incorporates the distance estimator. Follower UAVs are trained to detect the direction of flight of the leader and rotate as rigid body along the yaw-axis to realign themselves with the leader. We implemented the protocol using NS3-3.35 incorporated with mlpack machine learning library, and evaluated its performance using several experimental trials. The results demonstrate that the protocol achieves better, tolerable estimated distance error, formation stability, formation deviation error, and increased response time
2
Persson, Kristian, e Max Renberg. "Ambulance Safety: MADDE". Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-42610.
Testo completoAbstract (sommario):
Safety, a word that can be linked and interpreted in many different ways. Personal safety, that you should feel safe in your everyday life depending on your surroundings. IT security, to protect a persons or organization's valuable assets such as information. Flight safety, the safety of flying in its various kinds. There are safety issues in almost every area you look at, but this project that you will read about in this report is about traffic safety, more specifically, the safety of working in the back of an ambulance. Imagine working as an ambulance paramedic. You and your colleague have just picked up a “Prio 1” (most critical degree), classified patient who needs urgent care. You are sitting in the back of the ambulance and will take care of the patient while your colleague is driving the car. The situation is so critical that your colleague needs to drive as quickly as possible to get to the hospital in time. Thus, you must sit tight with a seat belt in order not to risk your own safety during the ride. Around you, there are a number of components you need to care of for the patient. You cannot reach these components because of the belt that clings to the chair. What are you going to do? Do you unbutton your belt to reach the components, but risk your own safety while driving? Or do you wear the belt incorrectly, so that you use the belt, but only over the hips (for example), so that you can reach the tools? Both of these alternatives are how the majority of ambulance paramedics use the seatbelt today to be able to do their job. Either you unbutton and release yourself completely from the belt or you use it, but incorrectly to reach everything the person in question needs in the ambulance. Both actions have resulted in a big amount of injuries to the caregivers and the numbers continues to increase continuously. This project is about just that. A solution to the problem of the working environment in the back of ambulances. Further in this report you will read about how two students at Halmstad University encountered the problem, but first and foremost how they solved it.Säkerhet, ett ord som kan kopplas och tolkas på många olika sätt. Personlig säkerhet, att man ska känna sig trygg i sin vardag beroende på omgivning. IT-säkerhet, att skydda en persons eller en organisations värdefulla tillgångar som exempelvis information. Flygsäkerhet, säkerheten vid flygning av dess olika slag. Det finns säkerhetsfrågor inom nästan varje område, men arbetet som du kommer få läsa om i denna rapport handlar om trafiksäkerhet, mer specifikt, säkerheten vid arbete bak i en ambulans. Föreställ dig att du arbetar som ambulanssjukvårdare. Du och din kollega har precis plockat upp en “Prio 1” (mest akuta graden), klassad patient som behöver akut vård. Du sitter bak i ambulansen och ska vårda patienten medan din kollega kör bilen. Läget är så kritiskt att din kollega behöver köra så snabbt som möjligt för att hinna till sjukhuset i tid. Därmed måste du sitta fastspänd med bilbälte för att inte riskera din egen säkerhet under körningen. Runtomkring dig finns det ett antal komponenter du behöver för att vårda patienten. Du når inte dessa produkter på grund av bältet som håller fast dig i sätet. Vad gör du? Knäpper du loss bältet för att kunna nå komponenterna, men riskerar din egen säkerhet under bilfärden? Eller tar du på dig bältet på ett inkorrekt sätt, så du sitter bältad, men bara över höfterna (exempelvis), så att du kan nå verktygen? Båda alternativen är hur majoriteten av ambulanssjukvårdare går till väga idag för att kunna utföra sitt jobb. Antingen knäpper man loss och frigör sig helt från bältet eller så använder man det, fast på ett inkorrekt sätt för att kunna nå allt personen i fråga behöver i ambulansen. Båda handlingarna har lett till flertalet skador på vårdarna och antalet fortsätter öka kontinuerligt. Arbetet handlar just om detta. En lösning på problemet med arbetsmiljön bak i ambulanser. Vidare i denna rapport kommer du få läsa om hur två studenter vid Högskolan i Halmstad kom i kontakt med problemet, men framförallt hur de fann en lösning till det.
3
Santos, Joana Isabel Fontes. "O efeito Maddie: análise da relação entre jornalistas e sistema judicial no desaparecimento de Maddie McCann". Master's thesis, [s.n.], 2009. http://hdl.handle.net/10284/1465.
Testo completoAbstract (sommario):
Dissertação de Mestrado apresentada à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências da Comunicação, especialização em Jornalismo.A notícia considerada como uma construção social da realidade, resulta da permanente troca e negociação de significado dos acontecimentos. As fontes de informação constituem uma dimensão indispensável para a compreensão e exercício do jornalismo. Todos os dias, os jornalistas vêem-se obrigados a ultrapassar inúmeras barreiras no exercício da sua profissão. Nem a liberdade de informar e ser informado podem ser concebidas em termos absolutos, nem as normas ético-legais podem ser ignoradas. O relacionamento existente entre os jornalistas e o sistema judicial é um dos grandes obstáculos que o jornalista tenta ultrapassar quando o seu objectivo é informar a opinião pública sobre algum caso judicial. A partir do Caso Maddie McCann, um dos acontecimentos mais mediáticos de 2007, analisei a influência inglesa nos media portugueses, assim como a relação que os jornalistas têm com conceitos judiciais e o relacionamento que têm com a Polícia Judiciária. The news are considered as a social construction of reality in permanent change and negotiation with public events. The sources of information are an essential dimension to the understanding and the exercise of journalism. Every day, journalists are obliged to overcome many obstacles in the exercise of their profession. Not the freedom to inform and be informed can be conceived in absolute terms, nor the ethical and legal standards can be ignored. The relationship between journalists and the judiciary is one of the major obstacles that the journalist tries to overcome when your aim is to inform the audiences about a court case. From the Maddie McCann case, one of the most mediatic in 2007, is examined the english influence on the portuguese media and the relationship between journalists, legal concepts and the portuguese police. L’article consideré comme une construction sociale de la réalité résulte de la permanente échange et négociation du sens des événements. Les sources d'informations constituent une dimension indispensable pour comprendre et faire du journalisme. Chaque jour, les journalistes se voient obligés de surmonter de nombreux obstacles dans l'exercice de leur profession. Ni la liberté d'informer et d'être informé peuvent être conçues en termes absolus, ni les normes éthiques et juridiques peuvent être ignorés. La relation entre les journalistes et le pouvoir judiciaire est l'un des principaux obstacles que le journaliste tente de surmonter lorsque son objectif est d'informer l’opinion publique sur une affaire judiciaire. De l'affaire Maddie McCann, l'une des plus médiatiques de 2007, j’ai analisée l'influence anglaise sur les médias portugais, ainsi comme la relation que les journalistes ont avec les concepts juridiques et le relationement qu'ils ont avec la police portugaise.
4
Maloney, Eric Daniel. "Frictional convergence and the Madden-Julian oscillation /". Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/10049.
Testo completo
5
Ray, Pallav Kumar. "The Initiation of the Madden-Julian Oscillation (MJO)". Scholarly Repository, 2008. http://scholarlyrepository.miami.edu/oa_dissertations/77.
Testo completoAbstract (sommario):
A mesoscale tropical channel model is constructed to study the long-standing problem of the initiation of the Madden-Julian Oscillation (MJO). Two observed cases of MJO are chosen, one in boreal spring and one in boreal winter, without a priori knowledge of their initiation mechanism. With initial and lateral boundary conditions provided by a global reanalysis, this model is able to reproduce the initiation and gross features of two observed MJO events up to two months after the start of simulations. This leads to a conjecture that these two MJO events are generated by the influences from the lateral boundaries. This conjecture is supported by a series of sensitivity tests. These sensitivity tests demonstrate that the simulated MJO initiation does not critically depend on detailed characteristics of sea surface temperature (varying vs. constant in time, mean distribution from boreal spring vs. winter), initial conditions (within a 10 day period, perturbations in the initial conditions), the latitudinal location of the lateral boundaries (21 - 45˚N and S), and even latent heating and moist processes. The only factor found critical to the reproduction of the MJO initiation is time varying lateral boundary conditions from the reanalysis. When such lateral boundary conditions are replaced by time independent conditions, the model fails to reproduce the MJO initiation. The analysis of moist static energy has revealed that the discharge-recharge mechanism is not sufficient for the MJO initiation in the model. It is found that the latitudinal transport of westerly momentum from the extratropics is crucial in generating the lower tropospheric westerlies in the reanalysis and model. The energy source for the extratropical perturbation is through extraction of kinetic energy from the mean flow. The estimation of wave activity flux has revealed that there is a major region over the southern Indian Ocean, which produces wave activity flux towards the tropical genesis region of the MJO initiation. We have also investigated the time-scale of the boundary conditions that are responsible for the MJO initiation. Additions of small perturbations in the boundary conditions, and use of 10-day interpolated boundary conditions do not affect the MJO initiation. Thus boundary conditions responsible for the MJO initiation in the model must have time scales greater than 10 days, indicating that the shorter time scale stochastic forcing through the lateral boundaries did not play any major role. The estimation of the zonal momentum budget for the MJO initiation region has revealed the importance of the advective terms, particularly by the meridional winds before the onset of the MJO. The importance of the extratropical influences in initiating the MJO in the channel model leads to a speculation that a multi-year simulation using a tropical channel model would also produce reasonable MJO statistics if forced by time varying boundary conditions. Interestingly, the MJO statistics in the multi-year simulation using a tropical channel model is found to be not better than the global models. Increase of horizontal resolution and use of a different cumulus scheme did not improve the MJO simulation. We found that the error in the mean state was the main reason for the lack of MJO statistics in the model. The model took less than five days for the error to reach its climate bias. Thus, a good simulation of the mean state is important for the successful simulation of the MJO. Implications of these results are discussed. In short, this study has shown that the extratropical influences can be an efficient mechanism for the MJO initiation and calls for further research attention to this mechanism that has been somewhat neglected by mainstream MJO research.
6
Saunders, M. W. M. "Ford Maddox Ford and the reading of prose". Thesis, University of Cambridge, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373696.
Testo completo
7
Singhruck, Patama. "Oceanic variability associated with the Madden-Julian oscillation". Thesis, University of East Anglia, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.504852.
Testo completoAbstract (sommario):
This study investigates the basin-wide oceanic variability associated with the Madden-Julian Oscillation (MJO) using new observations from the global array of profiling floats, known as Argo. Analysis of the Argo gridded data in a case study of the December 2003 to February 2004 MJO event in the Pacific Ocean reveals that the oceanic variability along the equator is characterised by an eastward propagating Kelvin wave response to the MJO surface wind stress anomalies. The observed phase speed and latitudinal structure are characteristics of the first baroclinic mode Kelvin wave. The vertical structures of these Kelvin waves are observed for the first time to extend downward to 1500 m. The amplitude of the deep ocean temperature anomalies is up to three times the amplitude ofthe observed annual cycle. With unprecedented coverage of salinity observations in the deep ocean provided by the Argo data, systematic changes in subsurface salinity variability during the MJO event are revealed for the first time. It is found that the salinity changes are associated with the Kelvin wave displacing isopycnals vertically. The composite study for the full period of the data set from January 2003 to December 2006 confirms the dominance of the Kelvin wave response in the subsurface temperature and salinity variability in the Pacific Ocean. Composites of sea surface temperature and sea surface salinity anomalies suggest the role of horizontal advection mediated by the Kelvin waves in addition to the MJO associated surface heat and fresh water fluxes variation. In the Indian Ocean, there is some evidence of a dynamical response to surface wind stress changes in the form of local upwelling and downwelling along 0°_5° Sin the central basin as well as in the equatorial eastern basin. However, the response did not exhibit propagating characteristics similar to the Pacific Ocean counterpart.
8
Batstone, Crispian Peter. "Ocean-atmosphere interactions within the Madden-Julian Oscillation". Thesis, University of East Anglia, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398818.
Testo completo
9
Sugiyama, Masahiro Ph D. Massachusetts Institute of Technology. "The Madden-Julian oscillation and nonlinear moisture modes". Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/42924.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2008.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 231-245).
The Madden-Julian oscillation (MJO), the dominant tropical intraseasonal variability with widespread meteorological impacts, continues to puzzle the climate research community on both theoretical and modeling fronts. Motivated by a recent interest in the role of humidity in tropical dynamics, this thesis hypothesizes that the MJO is a nonlinear moisture mode whose existence depends on moisture-convection feedback (the feedback between deep convection and environmental free-tropospheric humidity), and that weak moisture convection feedback in general circulation models accounts for their deficiencies with the MJO simulations. Moisture modes are found to exist in a large class of linear primitive equation models on the equatorial beta-plane. For models with standard quasi-equilibrium parameterizations,perturbation expansion analyses demonstrate that the weak temperature gradient (WTG) approximation of Sobel et al. describes the small-scale limit of the moisture mode accurately,with the small expansion parameter being the ratio between temperature tendency and adiabatic cooling. Under the WTG balance, the only leading order variables are humidity and vertical motion. Analyses of three models in the literature show that a moisture mode is unstable if moist static energy (MSE) sources such as cloud radiative forcing or gust-enhanced surface heat flux exceed the MSE export. Numerical calculations of a single-column model under the WTG configuration show that a realistic convective scheme can reproduce moisture mode instability. Sensitivity tests on the strength of moisture-convection feedback in the Emanuel scheme indicate that such a feedback is essential for moisture mode instability, confirming the prediction from simple models. To explore the nonlinear regime of a moisture mode, numerical calculations of a simplified Quasi-equilibrium Tropical Circulation Model on the equatorial beta-plane have been performed.
A classical Gill model augmented with a prognostic humidity variable can capture nonlinear dynamics of the moisture mode. In particular, nonlinear advection of dry air by Rossby gyres is found to move the moisture mode eastward. Notwithstanding progress made in the present thesis, numerous difficulties abound. The most significant issue is that moisture mode instability favors the smallest scale in the linear regime. The author suggests that scale interaction and its effect on the humidity budget might be an important research topic.
by Masahiro Sugiyama.
Ph.D.
10
Ferreira, Ana Cristina. "O caso Maddie, na imprensa nacional: a semana seguinte". Master's thesis, Universidade da Beira Interior, 2009. http://hdl.handle.net/10400.6/1578.
Testo completoAbstract (sommario):
Na opinião de vários estudiosos dos media, o caso Maddie reúne muitos dos ingredientes necessários para que o público tenha mantido o interesse elevado que vem relevando desde o início.
Se, à partida, trata-se “apenas” do desaparecimento de uma criança entre tantas outras, a verdade é que “uma menina inglesa, bonita, de olhos azuis, que desaparece num aldeamento turístico inglês, no Algarve, destino de férias tido por seguro pelos seus conterrâneos, é sempre uma janela aberta de oportunidade ao mediatismo”. (Edson Athayde, apud Carvalho et al., 2007: 14).
O caso do desaparecimento de Madeleine McCann terá sido, com certeza, um dos acontecimentos mais mediáticos e, sobretudo, marcantes que terão surgido nos meios de comunicação social durante os últimos dois anos.
Assim, neste trabalho procura-se encontrar a prioridade dada nas agendas dos meios de comunicação social a este caso, partindo dos conceitos de noticiabilidade e «agenda-setting» e do efeito do agendamento nos vários órgãos de comunicação social.In the view of many scholars in the media, the case Maddie meets many of the ingredients necessary for the public interest has kept the high that comes from falling within the top. If, at the outset, it is “only” the disappearance of a child among many others, the truth is that “an English girl, beautiful, blue-eyed, which disappears in an English tourist resort in the Algarve, had a holiday destination for insurance for their countrymen, it is always an open window of opportunity to the media”. The case of the disappearance of Madeleine McCann has been, without doubt, one of the most media and, especially, that have arisen marked in the media over the past two years. Thus, this work seeks to find a priority in the agendas of the media in this case, building on the concepts of news and «agenda-setting» and the effect of scheduling in various media.
11
Chang, Sabina. "Madang-Geuk : a missing component of third world drama /". Title page and contents only, 1995. http://web4.library.adelaide.edu.au/theses/09AR/09arc456.pdf.
Testo completo
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Carneiro, Iiona Anne-Marie. "Non-severe malarial disease in Madang, Papua New Guinea". Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360153.
Testo completo
13
Webber, Ben. "The dynamical ocean component of the Madden-Julian oscillation". Thesis, University of East Anglia, 2012. https://ueaeprints.uea.ac.uk/39456/.
Testo completo
14
Gregorio, Marília de Abreu. "Monitoramento da oscilação Madden Julian utilizando o método RMM". Instituto Nacional de Pesquisas Espaciais (INPE), 2015. http://urlib.net/sid.inpe.br/mtc-m21b/2015/02.25.20.10.
Testo completoAbstract (sommario):
Este estudo apresenta uma metodologia para monitorar a Oscilação Madden Julian (OMJ) derivada da técnica denominada \emph{Real Time Multivariate Madden Julian Oscilation} para a região Equatorial, durante o período de Janeiro de 2000 a Dezembro de 2010. Essa técnica foi adaptada para incluir a região da América do Sul e Oceano Atlântico e utiliza os dois pares principais de Funções Ortogonais Empíricas (EOFs) dos campos combinados dos dados de Radiação de Onda Longa (ROL), vento zonal em 850 hPa e vento zonal em 200 hPa, denominados RMM1 e RMM2. Esses índices descrevem a evolução e trajetória da OMJ ao redor do globo. Inicialmente apresenta-se uma analise das EOFs de ROL e do campo de vento para diagnosticar as características espaço-temporal dessas variáveis. Posteriormente apresenta-se uma análise do diagrama espaço-fase para acompanhar o deslocamento da OMJ em suas várias fases de seu ciclo de vida. Apresenta-se também uma analise da composição do ciclo de vida da OMJ em termos de ROL e do campo de vento. AS características gerais e sazonais dessa composição foram realizadas para avaliar os padrões espaciais e globais da variabilidade atmosférica associada ao índice RMM. Os resultados obtidos evidenciam as principais características de ROL e do campo de vento associadas à propagação da OMJ, destacando principalmente a propagação da atividade convectiva e a variabilidade das anomalias do vento zonal na região equatorial. A amplitude do sinal da OMJ possibilitou inferir adequadamente a intensidade desse fenômeno, ao passo que a composição do ciclo de vida da OMJ contribui para um melhor entendimento da estrutura dinâmica desse fenômeno.This study presents a methodology for monitoring the Madden Julian Oscillation (MJO) derived from Real Time Multivariate Madden Julian Oscillation technique for the Equatorial region, during January 2000 to December 2010. This technique was adapted to include South America and Atlantic Ocean regions. It uses the two mainly pairs of Empirical Orthogonal Function (EOF) for combined fields of the Outgoing Longwave Radiation (OLR), zonal wind at 850 hPa and zonal wind at 200 hPa, called RMM1 and RMM2. These indices describe the evolution and trajectory of the MJO around the globe. Firstly, it presents an analysis of the EOF for ROL and wind field to diagnose the spatio-temporal characteristics of these variables. Secondly, it presents an analysis of the phase space diagram to see the displacement of MJO in various phases of its life cycle. Furthermore, we present an analysis of the MJO's life cycle composition in terms of OLR and of the wind field. General and seasonal characteristics of this composition were done to evaluate the spatial and global patterns of the atmospheric variability associated with the RMM index. The results show the main features of OLR and wind field associated with spread of MJO, especially highlighting the spread of convective activity and the variability of zonal wind anomalies in the equatorial region. The amplitude of the MJO's signal enable infer the intensity of this phenomenon properly, whereas the composition of the MJO's life-cycle contributes to a better understanding of the dynamic structure of this phenomenon.
15
OLIVEIRA, Juarez Ventura de. "A oscilação Madden - Julian na Amazônia Oriental: variáveis superfíciais". Universidade Federal do Pará, 2012. http://repositorio.ufpa.br/jspui/handle/2011/6847.
Testo completoAbstract (sommario):
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Tendo como foco as múltiplas escalas de tempo que atuam na Amazônia, este trabalho foi desenvolvido com o objetivo de investigar a possível influencia da Oscilação Madden – Julian (OMJ) em elementos turbulentos da CLP. A OMJ foi identificada a partir de 30 anos de dados de reanálise de radiação de onda longa (ROL) e componente zonal do vento (u). As grandezas turbulentas foram estudadas a partir da variância, covariância e coeficiente de correlação de um conjunto de dados de resposta rápida coletado na torre micrometeorológica de Caxiuanã (PA), e tratados com a Transformada em Ondeletas (TO) para se obter a contribuição de cada escala para estes momentos estatísticos. A análise dos 30 anos de dados de ROL e u mostrou que a ocorrência da OMJ está ligada com o fenômeno do El Niño/Oscilação Sul (ENOS), bem como influência do ENOS no tempo da região amazônica pode estar associado a presença ou não da OMJ. Foi observado que anos de El Niño tendem a desfavorecer a ocorrência da OMJ e anos de La Niña tendem a favorecer o desenvolvimento da oscilação. Caso uma OMJ se desenvolva durante um episodio de El Niño, a oscilação pode influenciar a temperatura, a velocidade do vento e a precipitação de forma diferente ao do El Niño. A análise por fase da OMJ mostrou que, em Belém, há diferença significativa na temperatura máxima e na precipitação entre cada fase, porém, a temperatura mínima e o módulo do vento apresentaram pouca diferença. Os fluxos cinemáticos turbulentos analisados, por escala, em três horários distintos, foram mais diferentes durante o período diurno, principalmente w’T’ e w’q’. A diferença entre fase ativa e fase inativa foi reduzindo com passar do dia, durante o período de transição dia – noite, poucas escalas tiveram diferença significativa, e durante a noite, nenhuma escala teve nível de confiança acima ou igual a 95%. Estes resultados indicam que a convecção diurna é o mecanismo responsável por esta diferença e como a OMJ atua como uma grande célula convectiva, a convecção local é amplificada, explicando a grande diferença observada entre as fases durante o período diurno.
The aim of this work is to investigate the influence of the Madden - Julian Oscillation (MJO) on turbulent elements of the Atmospheric Boundary Layer (ABL). The MJO was identify on a time series of 30 years of outgoing long-wave radiation (OLR) and zonal component of the wind (u). The turbulent parameters were studied through the covariance and the correlation coefficient of a fast response data set collected on Caxiuanã’s (Pa) micrometeorological tower. The difference between each phase of the MJO was statistically analyzed with the t test of Student. The OLR and u data set results shows that the MJO occurrence is linked to El Niño / Southern Oscillation (ENSO) happening. The El Niño phase of an ENSO tends to diminish the chances of MJO case to develops, the opposite situation is identify during an La Niña episode, when the MJO is favored by the dynamics of the ongoing ENSO mechanism. If a MJO occurs during an El Niño, it can change the temperature, wind velocity and the precipitation expected for an El Niño year. The MJO’s phase analysis, for Belém, reveled a significant difference on precipitation and maximum temperature between the active and inactive phase, but for minimum temperature and wind module, this difference is little significant. The turbulent kinematic fluxes, analyzed by scale on each phase of the MJO, during three different periods of the day, were more distinct during the daytime period, with high confidence levels, mostly on w’T’ and w’q’ fluxes. The day – night transition and the night period were less different, with only a few scales showing more than or exactly 95% of confidence during the transition, and with none scales reaching the 95% mark during the night. Those results indicate that the diurnal convection is the responsible mechanism for this differences, and as the MJO is like a big convective cell, the local convection during its active phase is amplified, explaining the differences found during the daytime period.
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Tran, Tram Anh Teresa. "Convergence: A New Future for the Samuel Madden Homes". Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/90881.
Testo completoAbstract (sommario):
Housing in prosperous American cities is becoming increasingly expensive, forcing many municipal governments to re-evaluate how they will continue to serve lower-income residents and ensure equitable access to housing and resources. In the City of Alexandria, the Alexandria Re-Development and Housing Authority (ARHA) has worked in recent years to partner with private developers to convert its existing stock of low-density, designated-affordable housing into more dense, mixed-income communities. This is possible because many of its existing communities sit on land in now-prime locations where the City currently allows the most density, as well as bonus density through a variety of mechanisms.
While these projects have succeeded to some extent, the City is unfortunately still seeing a rapid rise in rents accompanied by a rapid decrease in available affordable housing of all types, in both privately-developed and publicly-subsidized communities. Increasing income disparity is also simultaneously driving lower-income to middle-class residents to suburban and exurban sites where limited access to municipal resources and public transportation can be highly detrimental to quality of life.
While additional density is the knee-jerk response to many of affordability's challenges, often the resulting built solutions seem incomplete – achieving the basic goal of housing more residents, but failing to build thriving and diverse communities that connect people the way previous communities may have. After all, the pragmatics of building generally point towards maximizing square footage, monetary return, and speed of delivery by using conventional and commonly-accepted solutions, with less energy given to resident outcomes, and how people might be affected by the change to their living environments and communities.
As Jan Gehl and Jane Jacobs examined in Cities for People and The Death and Life of Great American Cities respectively, simple pragmatics do not make for livable environments. A truly humanist approach to design for living in cities requires not only good policy, practice, and engagement, but also architectural strategies that respond to how humans relate to each other and their surroundings.
Convergence explores how designers can contribute to making urban housing better for everyone by addressing housing affordability, person-to-person interaction, and community engagement in increasingly-dense environments.
Its primary objectives are:
• Encouraging neighborliness by increasing chance encounters as well as reducing the sharp threshold between private and public space often found in apartment-style buildings.
• Increasing the visibility of human activity to the street in a multi-floor, multi-family project.
• Using new mass timber methods and modularity to improve initial building construction and cost while also incorporating sustainable practices to reduce resource use and operating cost.
• Anticipating that modification and reconfiguration will be required in the future, and offering defined parameters to simplify that process.
• Creating a variety of unit sizes while also offering future flexibility to respond to changing community needs.
• Combining the familiar with the novel to connect the new community to its surroundings, bridge experiences, and manage change.Master of Architecture
In the City of Alexandria, the Alexandria Re-Development and Housing Authority (ARHA) owns several affordable housing sites in desirable locations that it has been working to convert into more dense, mixed-income housing in partnership with private developers. While these projects have succeeded to some extent, housing in the City continues to become increasingly expensive, and wages for low-income and lower-middle class residents are not keeping pace with the increase in cost of living. This phenomenon is pushing many long-time and/or lower-wage residents to the suburbs and exurbs, limiting access to municipal resources and public transportation, and reducing quality of life. As a result, communities and families with long histories in the City are breaking apart and dispersing. Many advocates, policymakers, designers, and developers have turned to additional density as the most immediate response to these concerns. However, additional density isn’t enough; new buildings may house more people, but fail to address the other aspects of building thriving and diverse communities that connect people the way previous communities may have. Good housing and good communities need more than square footage, so it is time to look beyond conventional solutions. New approaches are needed to respond to how people are affected by changes to their living environments and communities, and create the kinds of positive outcomes that should be part of any new housing project. Therefore, if we want to design for living in cities, we have to have good policies, practices, and engagement, but we also need architectural strategies that respond to how humans relate to each other and their surroundings. Convergence explores how designers can contribute to making urban housing better for everyone by addressing housing affordability, person-to-person interaction, and community engagement in increasingly-dense environments. Its primary objectives are: • Encouraging neighborliness by increasing chance encounters as well as reducing the sharp threshold between private and public space often found in apartment-style buildings. • Increasing the visibility of human activity to the street in a multi-floor, multi-family project. • Using new mass timber methods and modularity to improve initial building construction and cost while also incorporating sustainable practices to reduce resource use and operating cost. • Anticipating that modification and reconfiguration will be required in the future, and offering defined parameters to simplify that process. • Creating a variety of unit sizes while also offering future flexibility to respond to changing community needs. • Combining the familiar with the novel to connect the new community to its surroundings, bridge experiences, and manage change.
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Ingram, Andrew. "Anamuxra : a language of Madang Province, Papua New Guinea". Thesis, The University of Sydney, 2001. http://hdl.handle.net/2123/9823.
Testo completo
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Madden, Kathryn R. "The use of inquiry-based instruction to increase motivation and academic success in a high school biology classroom". Montana State University, 2011. http://etd.lib.montana.edu/etd/2011/madden/MaddenK0811.pdf.
Testo completoAbstract (sommario):
A variety of inquiry based lessons and non inquiry based lessons were used to motivate and increase academic success with a freshman biology honors students. Student self surveys, biology journals, and lab skills were indicators of motivation. Scores on standardized tests and other assessments were used to monitor students' academic success. Trends indicated an increase in student motivation to do science while testing scores were varied.
19
Liess, Stefan. "Model studies of the tropical 30 to 60 day oscillation Modelluntersuchungen der tropischen 30 bis 60 Tage Oszillation /". [S.l. : s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=964418568.
Testo completo
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Elerson, Crystal L. "Claremont Connections". Thesis, University of North Texas, 2004. https://digital.library.unt.edu/ark:/67531/metadc4551/.
Testo completo
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Anderson, Thomas. "Modification of a Madden-Julian oscillation index and its applications". Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=106452.
Testo completoAbstract (sommario):
The Madden-Julian Oscillation (MJO) is the dominant component of the intraseasonal atmospheric variability in the tropics. The MJO signal consists of deep convection and overturning atmospheric zonal circulations propagating slowly eastward along the equator. Wheeler and Hendon (2004) developed a method of extracting the MJO signal based on the two leading empirical orthogonal functions (EOFs) of the combined fields of near-equatorially averaged zonal wind at 850-hPa and 200-hPa as well as the observed outgoing long wave radiation (OLR). The length of this index in time is severely limited by the inclusion of the OLR data, as this time series only goes back to June 1974 and becomes a problem when trying to study the long-term aspects of the MJO. A modified index based on a combined EOF analysis of the 200-hPa and 850-hPazonal wind fields is developed and validated against Wheeler and Hendon's index. This allows the limitation of the relatively short OLR data set to be circumvented, as wind reanalysis data extends back farther in time, while keeping the benefit of a high MJO signal extraction through combined EOF analysis. As the results show, the new index yields nearly identical results to the older, more restrictive index. Therefore, the modified index is used to analyze the behavior of the MJO on time scales longer than the inter-annual, MJO- ENSO interaction and the ability of the Global Environmental Multiscale(GEM) model to represent the MJO.L'Oscillation de Madden-Julian (MJO) est la composante dominante de la variabilité atmosphérique intra-saisonnière dans les tropiques. Le signal MJO consiste en une convection profonde et d'une circulation zonale se propageant lentement vers l'Est le long de l'Équateur. Wheeler et Hendon (2004) ont développé une méthode pour extraire le signal du MJO basée sur les deux fonctions orthogonales empiriques dominantes (EOFs) des champs combinés du vent zonal à 850-hPa et 200-hPa près de l'Équateur ainsi que la radiation de large onde sortante (OLR). L'étendue temporelle de cet indice est sévèrement limitée par l'inclusion des données OLR, puisque ces données sont disponnibles seulement depuis juin 1974, limitant l'étude des aspects àlong terme du MJO. Un indice modifié, basé sur l'analyse EOF combinée du vent zonal à 200-hPa et 850-hPa est developpé et validé avec l'indice de Wheeler et Hendon. Ceci permet l'élimination les limitations associées à la disponibilité des données OLR étant donné que les réanalyses numériques présentent des données de vent pour une période plus étendue et ceci en gardant les bénéfices d'une extraction robuste du signal du MJO par analyse EOF combinée. Comme les résultats le montrent, le nouvel indice présente des résultats presques identiques à l'ancienne et plus restrictive version de l'indice. L'indice modifié est donc utilisé pour analyser le comportement du MJO sur des échelles temporelles au delà de l'échelle saisonnière, les interactions MJO-ENSO et la capacité du modèle Global Environmental Multi-Échelle (GEM) à représenter le MJO.
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Inness, Peter Michael. "Representation of the Madden-Julian oscillation in general circulation models". Thesis, University of Reading, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.394426.
Testo completo
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Madden, James D. [Verfasser]. "Strategie in volatilen Märkten. : Wettbewerbsvorteile durch Unternehmungsdiversifikation. / James D. Madden". Berlin : Duncker & Humblot, 2016. http://d-nb.info/1238439578/34.
Testo completo
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Moskowitz, Benjamin M. "An analysis of frictional feedback in the Madden-Julian oscillation /". Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/6791.
Testo completo
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Charlesworth, Oliver. "Intraseasonal European climate variability and interactions with the Madden-Julian Oscillation". Thesis, University of East Anglia, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.490613.
Testo completoAbstract (sommario):
The seasonally-varying interaction between the Madden-Julian Oscillation (MJO) and .the northern extratropics, specifically the North Atlantic and Europe region, on intraseasonal timescales is studied. When the MJO is observed using composite and Monte-Carlo significance testing, a direct response to the tropical dynamics is found over the North Atlantic and Europe. When the MJO convection is active over the Indian Ocean, significant anticyclonic anomalies at the 95% confidence level are frequently found over the UK and eastern North Atlantic region. Approximately 10 to 20 days later, when the MJO convection is active over Indonesia, the extratropical anomalies occur in similar locations with opposite sign. Using a systematic two-month sliding season approach to investigate the interaction, the anomalies are present for the majority of the year, favouring the boreal spring. The relationship between the MJO and the North Atlantic Oscillation (NAO) for each of the 12 seasons throughout the year is quantified for the first time using regression analysis. Although correlations between the MJO and NAO are weak, further regressions between the MJO and a North Atlantic 1000 hPa geopotential height index just east of the UK gives very strong boreal springtime correlations of up to r=0.50 and anti-correlations of r=-0.53. An Intermediate Global Circulation Model (IGCM) is used to model the MJO to investigate the mechanisms behind the strong tropical-extratropical interactions. Various stages of representing the MJO in the model are presented using fixed and time dependent heating profiles and many of the observed extratropical features are reproduced as a response to the forcing. Direct comparisons between the observations and the model results are made and the level at which it is able to reproduce the North Atlantic and European anomalies is discussed.
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Khoj, Adnan. "Le premier chanteur compositeur saoudien et du Golf arabe : Talal Maddah". Paris 1, 2008. http://www.theses.fr/2008PA010580.
Testo completoAbstract (sommario):
Le travail commence par présenter le thème et les objectifs de la recherche, avant d'en souligner I'importance et I'étendue, et d'en préciser la méthode, le contenu et les outils. Ensuite, et pour permettre au lecteur d'avoir une idée du contexte socioculturel du chanteur, nous avons donné un aperçu de l'histoire du Royaume avant de présenter la biographie de Talal Maddah, les points de repère dans sa vie, les hommes de lettres et les artistes qu'il a connus et dont la connaissance a permis de créer une collaboration fructueuse et enrichissante, aussi bien pour notre artiste que pour ces partenaires. Le troisième chapitre de la thèse est consacré à l'analyse des chansons que nous avons réussi à réunir. Ce travail technique met en évidence les traits caractéristiques de I'art de Talal Maddah dont nous avons parlé précédemment. Notre travail se termine par une conclusion où nous récapitulons les résultats de notre recherche et faisons quelques propositions.
27
King, Emma. "Post-translational regulation of Mad3p in Saccharomyces cerevisiae". Thesis, University of Edinburgh, 2005. http://hdl.handle.net/1842/15167.
Testo completoAbstract (sommario):
Mad3p is a component of the spindle checkpoint in Saccharomyces cerevisiae. Mad3p is known to be in a constitutive complex with another checkpoint component Bub3p and upon checkpoint activation it interacts with Mad2p and Cdc20p to form the mitotic checkpoint complex. Recent analysis also suggests that the Mad proteins, in addition to the direct inhibition of Cdc20p through formation of the mitotic checkpoint complex, have an additional role in the down-regulation of Cdc20p levels in the cell. The results presented in this thesis show Mad3p to be a protein that is phosphorylated during every mitosis and consequently upon spindle checkpoint activation. Such phosphorylation does not require any other checkpoint components. Experiments also show that Mad3p is phosphorylated on serine 337 by Ipllp kinase in vitro and the phosphorylation of Mad3p in vivo, due to an absence of tension at the kinetochore, requires Ipllp. Mad3p contains two KEN box motifs that are conserved between species. Evidence in this thesis demonstrates that mutation of either of these KEN boxes renders cells sensitive to microtubule depolymerising drugs. Further analysis of these mutants shows that Cdc20p binding is reduced in both but they can both still bind Bub3p. Mutation of the N-terminal KEN box increases the half-life of Cdc20p and consequently the total levels of Cdc20p in the cell. Cdc20p turnover is also reduced in the absence of Bublp and Bub3p, but to a lesser extent. Mutation of the second KEN box in Mad3p leads to a dominant phenotype that perturbs mitosis even in the presence of wildtype Mad3p.
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Pohl, Benjamin. "L'Oscillation de Madden-Julian et la variabilité pluviométrique régionale en Afrique Subsaharienne". Phd thesis, Université de Bourgogne, 2007. http://tel.archives-ouvertes.fr/tel-00269077.
Testo completoAbstract (sommario):
Le rôle de l'Oscillation de Madden-Julian ("MJO") sur la variabilité pluviométrique de l'Afrique Subsaharienne est ici examiné, à l'aide de relevés pluviométriques quotidiens et des réanalyses NCEP-DOE AMIP-II. Le signal convectif et dynamique associé à la MJO est extrait à l'aide de deux méthodes statistiques, les indices journaliers du BMRC (Wheeler & Hendon 2004) et une analyse en modes locaux ("LMA", Goulet & Duvel 2000). Dans un premier temps, la variabilité temporelle de l'oscillation est abordée à l'échelle de la ceinture tropicale (période, amplitude, saisonnalité, localisation des anomalies convectives). Si l'amplitude globale du signal n'apparaît pas reliée à El Niño, les oscillations se produisant lors des années El Niño (La Niña) tendent à être plus courtes (longues). Les conditions de surface (dont les température de surface marine) et le cycle annuel sont également des paramètres influant fortement sur la localisation des anomalies convectives les plus marquées associées à la MJO. Dans un second temps, la réponse de la pluviométrie à la MJO est examinée dans 3 ensembles régionaux de l'Afrique Subsaharienne. Dans les 3 cas examinés, la (les) saison(s) des pluies est (sont) significativement affectée(s). Sur l'Afrique de l'Est Equatoriale (Kenya, nord de la Tanzanie), les Hautes Terres d'Afrique montrent l'alternance d'une phase humide et d'une phase sèche au cours du cycle de la MJO. Les mécanismes pluviogènes font intervenir essentiellement la convection atmosphérique profonde. Sur les Basses Terres de l'est en revanche, et sur les plaines littorales, le pic de pluie est enregistré en opposition de phase par rapport aux Hautes Terres, et est relié à un renforcement des alizés depuis l'océan Indien. Une influence significative est également trouvée en Afrique Australe (sud de 15°S), et résulte d'un renforcement de l'anticyclone des Mascareignes, qui favorise via une circulation anticyclonique sur l'Afrique, un apport d'humidité sur la région depuis l'océan Indien tropical. Sur l'Afrique de l'Ouest enfin, la MJO est avant tout impliquée dans une baisse récurrente de la pluviométrie, et très secondairement seulement dans une amplification des cumuls journaliers. Cette dernière ne semble pas résulter uniquement de processus convectifs. L'exemple des Long Rains d'Afrique de l'Est (mars à mai) est ensuite utilisé pour explorer les interactions d'échelle dont la MJO est à l'origine. Aux pas de temps "courts", le cycle diurne de la convection est sensiblement modifié d'une phase de la MJO à l'autre ; les dates de démarrage de la saison des pluies et les évènements pluviométriques exceptionnels montrent également un calage très bon sur la phase de la MJO. Aux pas de temps "longs", une partie significative de la variabilité interannuelle des Long Rains est statistiquement corrélée à l'amplitude saisonnière moyenne de la MJO, qui semble dont rajouter régulièrement de la pluie sur la région plutôt que d'amplifier seulement les écarts entre les phases les plus humides et les plus sèches.
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Andersen, Joseph. "Investigations of the Convectively Coupled Equatorial Waves and the Madden-Julian Oscillation". Thesis, Harvard University, 2012. http://dissertations.umi.com/gsas.harvard:10438.
Testo completoAbstract (sommario):
The Madden-Julian Oscillation (MJO) and the Convectively Coupled Equatorial Waves (CCEW) are coherent structures of convection and various large-scale fields. These phenomena are not well understood, despite their importance to the tropical climate. A toy model of the CCEW consisting of a pair of shallow water wave modes coupled by a simple convective parameterization is considered. The linear behavior of the system is analyzed, showing a growth spectrum that is similar to the spectrum that is observed. To explore the processes involved in propagation and maintenance of the MJO disturbance, we analyze the MSE budget of the disturbance within a numerical model. In an idealized experiment, the column-integrated long-wave heating is the only significant source of column-integrated MSE acting to maintain the MJO-like anomaly balanced against the combination of column-integrated horizontal and vertical advection of MSE and Latent Heat Flux. Eastward propagation of the MJO-like disturbance is associated with MSE generated by both column-integrated horizontal and vertical advection of MSE, with the column long-wave heating generating MSE that retards the propagation. The contribution to the eastward propagation by the column-integrated horizontal advection term is dominated by meridional advection of MSE by anomalous synoptic eddies caused by the suppression of eddy activity ahead of the MJO convection. This suppression is linked to the barotropic conversion mechanism; with the gradients of the low frequency wind experienced by the synoptic eddies within the MJO envelope acting to modulate the Eddy Kinetic Energy. The meridional eddy advection’s contribution to poleward propagation is dominated by the mean state’s (meridionally varying) eddy activity acting on the anomalous MSE gradients associated with the MJO. In a follow-up experiment, the variations in the propagation speed of MJO with variations in the imposed SST distribution are seen to be driven by the variations in meridional advection of the mean MSE profile by the MJO-related winds, which are in turn dominated by the variations in the mean MSE profile due to the variations of the SST. A brief investigation of the MSE budget for a more realistic case shows an increase in the MSE sink due to meridional advection as the MJO progresses from genesis over the Indian Ocean to decay in the central Pacific. The increase in this sink appears to be the cause of MJO’s demise.Physics
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Silva, Elaine Rosângela Leutwiler di Giacomo. "Oscilação de Madden e Julian: dados observados e simulados pelo modelo RegCM4". Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/8/8135/tde-18092018-150731/.
Testo completoAbstract (sommario):
O presente trabalho propõe avaliar a habilidade do Modelo Regional Climático, versão 4, (RegCM4) em simular a variabilidade temporal e espacial do sinal associado à propagação da Oscilação de Madden-Julian (OMJ) nos trópicos. A avaliação foi feita através da comparação dos dados observados obtidos do conjunto da Reanálise do ERA-Interim e dos dados simulados pelo RegCM4, para o período de 2005 a 2009. Foram utilizados dados globais diários de precipitação, Radiação de Onda Longa Emergente e componentes zonal do vento em 850 e 200 hPa, provenientes da Reanálise do ERA-Interim, tanto na simulação, quanto nos dados observados. Como condição inicial do modelo, optou-se pela utilização da banda tropical, cujo principal aspecto é o de simular características tanto da circulação quanto dos padrões de precipitação tropicais. Para a validação do modelo, foi utilizada a precipitação diária do Global Precipitation Climatology Project (GPCP). Todos os dados foram filtrados na escala de 30-60 dias a fim de se observar o sinal referente à OMJ. A análise dos padrões globais de precipitação e Radiação de Onda Longa (ROL), após filtragem, permitiu a seleção de cinco áreas, com sinais associados à OMJ, sendo elas: África (AFR), Indonésia (IND), Norte da América do Sul (NAS), Nordeste brasileiro (NEB) e Sudeste brasileiro (SEB). A área NEB, apresentou valores de correlação linear de 0,63 e 0,32 para a anomalia e anomalia de ROL filtrada, respectivamente. Já a área SEB, apresentou valores de correlação linear de 0,30 e 0,54, para a anomalia e anomalia de ROL filtrada. O BIAS calculado entre o modelo e a precipitação do GPCP, para as estações secas (MAI-OUT) e chuvosas (NOV-ABR) mostrou que para a América do Sul, Sul do continente Africano e Índico, o modelo superestima os valores de precipitação do GPCP nas duas estações do ano. Quanto à análise multivariada entre a ROL, vento zonal em 850 e 200 hpa a comparação com o obtido para os dados do Era-Interim, a Empirical Orthogonal Function (EOF1) aplicada aos dados do RegCM4 apresenta convecção e inibição da convecção em áreas distintas da faixa longitudinal entre 15º N e 15º S. Enquanto os valores mínimos de EOF1 para ROL (intensificação da convecção) do Era-Interim são observados próximo a 90º L, os valores mínimos de ROL para os dados do RegCM4 são observados próximos à 120º O, com defasagem longitudinal de 30º. L, enquanto os valores máximos da EOF1 para ROL (inibição de convecção) do Era-Interim são observados próximo a 150º L, os valores máximos para os dados simulados pelo RegCM4 são observados próximos à 60º L, com uma defasagem longitudinal de 90°.The present work proposes to evaluate the ability of the Regional Climatic Model (RegCM4) to simulate the temporal and spatial variability of the signal associated with the propagation of the Madden-Julian Oscillation in the tropics. The evaluation was done by comparing the observed data obtained from the Reanalysis of the ERA-Interim and the data simulated by RegCM4, for the period from 2005 to 2009. Daily global data were used for precipitation, Emergent Long Wave Radiation and zonal wind components at 850 and 200 hPa from the ERA-Interim Reanalysis, both in the simulation and in the observed data. As initial conditions of the model, we chose to use the tropical band, whose main characteristic is to simulate the circulation and the tropical precipitation patterns. The validation of the model was performed with the daily precipitation of the Global Precipitation Climatology Project (GPCP). All data were filtered in the 30-60 day scale in order to observe the signal concerning the MJO. The analysis of the global precipitation and Outgoing Longwave Radiation (OLR) patterns, after filtration, allowed the selection of five areas, with signs associated to the MJO, being: Africa (AFR), Indonesia (IND), North of South America (NAS), Northeast Brazil (NEB) e Southeast Brazil (SEB). The NEB area presented linear correlation values of 0,63 and 0,32 for the anomaly and filtered anomaly of OLR, respectively. The SEB area presented linear correlation values of 0.30 and 0.54 for the anomaly and anomaly of filtered OLR. The BIAS calculated between the model and GPCP precipitation for the dry (MAY-OCT) and rainy seasons (NOV-APR) showed that for South America, South Africa and Indian continent, the model overestimates precipitation values of GPCP in the two seasons. The multivariate analysis between OLR, zonal wind at 850 and 200 hp compared to that obtained for Era-Interim data, the EOF1 applied to RegCM4 data presents convection and convection inhibition in different areas between 15º N and 15º S. While the minimum Empirical Orthogonal Function (EOF1) values for OLR (convection enhancement) of the Era-Interim are observed close to 90º E, the minimum OLR values for the RegCM4 data are observed close to 120º O, with a longitudinal lag of 30º. And while maximum EOF1 values for OLR (convection inhibition) of the ERA-Interim are observed close to 150º E, the maximum values for the simulated data by RegCM4 are observed close to 60º E, with a longitudinal lag of 90º.
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Valad?o, Cati Elisa de Avila. "Impacts of the Madden-Julian oscillation on intraseasonal precipitation over northeast Brazil". Universidade Federal do Rio Grande do Norte, 2015. http://repositorio.ufrn.br/handle/123456789/20695.
Testo completoAbstract (sommario):
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)
The impacts of the Madden?Julian Oscillation (MJO) on precipitation over Northeast Brazil (NEB, also known as Nordeste) are evaluated based on daily raingauge data from 492 stations over 30-year period (1981-2010). Composites of precipitation, outgoing longwave radiation and moisture-flux anomalies are performed for each phase of the MJO based on the Jones?Carvalho MJO index. To distinguish the MJO signal from other patterns of climate variability, daily data are filtered using a 20 - 90 day band-pass filter; only days classified as MJO events are considered in the composites. A preliminary analysis based on precipitation data was conducted for a small scale area located in NEB?s semiarid interior, in an area known as Serid?. The Serid? is one of the driest regions in NEB, and is recognized by the United Nations Convention to Combat Desertification as particularly vulnerable to desertification. Composites of rainfall anomalies were computed for each of the eight phases of the MJO during February-May, which is Serid??s main rainy season. Results showed that the rainfall patterns in Serid? undergo substantial changes (from enhancement to suppression) as the convective center of the MJO propagates eastward. When combining the MJO signals for wet and dry phases, the difference represents about 50 - 150% modulation of the mean rainfall over Serid?. Then a comprehensive analysis of the role of the MJO in modulating the spatiotemporal variation of NEB?s precipitation was performed, considering all four seasons. The results showed strong seasonality of the MJO impact on precipitation. The most spatially coherent signals of precipitation anomalies occurred in the austral summer, when about 80% of the raingauge stations showed increased precipitation during phases 1 - 2 and suppressed precipitation in phases 5 - 6 of the oscillation. Although the MJO impacts precipitation on intraseasonal timescales in all seasons in most locations, these impacts vary in magnitude and depend on the phase of the oscillation. Precipitation anomalies over NEB are explained by the interaction of convectively coupled Kelvin-Rossby waves with the dominant climatic features in each season. During the austral summer and spring, westerly regimes increased precipitation over most NEB. In the austral winter and fall, precipitation anomalies exhibited more complex spatial variability. In these seasons precipitation anomalies in eastern coastal areas depended on the strength of the South Atlantic anticyclone, which is largely modulated by Rossby waves. The strengthening of the anticyclone intensified the convergence of the trade winds in coastal areas and precipitation windward of the coastal range. Conversely, the intensification of the subsidence was responsible for precipitation deficits in the lee side of the range. These conditions were typically observed when easterly regimes dominate over tropical South America and NEB, decreasing moisture flow from the Amazon.
Este estudo tem como objetivo investigar os impactos da oscila??o de Madden-Julian (OMJ) na precipita??o da regi?o Nordeste do Brasil (NEB). Para tanto foram utilizados dados di?rios de precipita??o baseados em 492 pluvi?metros distribu?dos na regi?o e cobrindo um per?odo de 30 anos (1981 ? 2010). As an?lises atrav?s de composi??es de anomalias de precipita??o, radia??o de onda longa e fluxo de umidade, foram obtidas com base no ?ndice da OMJ desenvolvido por Jones-Carvalho. Para distinguir o sinal da OMJ de outros padr?es de variabilidade clim?tica, todos os dados di?rios foram filtrados na escala de 20 ? 90 dias; portanto somente dias classificados como eventos da OMJ foram considerados nas composi??es. Uma an?lise preliminar baseada apenas nos dados de precipita??o foi feita para uma pequena ?rea localizada no interior semi?rido do NEB, conhecida como Serid?. Essa microrregi?o ? uma das ?reas mais secas do NEB e foi reconhecida pela Conven??o das Na??es Unidas para o Combate ? Desertifica??o e Mitiga??o dos Efeitos das Secas como particularmente vulner?vel ? desertifica??o. Composi??es de anomalias de precipita??o foram feitas para cada uma das oito fases da OMJ durante Fevereiro-Maio (principal per?odo chuvoso da microrregi?o). Os resultados mostraram a exist?ncia de varia??es significativas nos padr?es de precipita??o (de precipita??o excessiva ? deficiente) associados ? propaga??o da OMJ. A combina??o dos sinais de precipita??o obtidos durantes as fases ?midas e secas da OMJ mostrou que a diferen?a corresponde cerca de 50 ? 150% de modula??o das chuvas na microrregi?o. Em seguida, uma investiga??o abrangente sobre o papel da OMJ sobre toda a regi?o Nordeste foi feita considerando-se as quatro esta??es do ano. Os resultados mostraram que os impactos da OMJ na precipita??o intrassazonal do NEB apresentam forte sazonalidade. A maior coer?ncia espacial dos sinais de precipita??o ocorreram durante o ver?o austral, quando cerca de 80% das esta??es pluviom?tricas apresentaram anomalias positivas de precipita??o durante as fases 1 ? 2 da OMJ e anomalias negativas de precipita??o nas fases 5 ? 6 da oscila??o. Embora impactos da OMJ na precipita??o intrassazonal tenham sido encontrados na maioria das localidades e em todas as esta??es do ano, eles apresentaram varia??es na magnitude dos sinais e dependem da fase da oscila??o. As anomalias de precipita??o do NEB observadas s?o explicadas atrav?s da intera??o existente entre as ondas de Kelvin-Rossby acopladas convectivamente e as caracter?sticas clim?ticas predominantes sobre a regi?o em cada esta??o do ano. O aumento de precipita??o observado sobre a maior parte do NEB durante o ver?o e primavera austrais encontra-se associado com o fluxo de umidade de oeste (regime de oeste), o qual favorece a atividade convectiva em amplas ?reas da Am?rica do Sul tropical. Por outro lado, as anomalias de precipita??o durante o inverno e outono austrais apresentaram uma variabilidade espacial mais complexa. Durante estas esta??es, as anomalias de precipita??o observadas nas esta??es localizadas na costa leste do NEB dependem da intensidade do anticiclone do Atl?ntico Sul, o qual ? modulado em grande parte por ondas de Rossby. As caracter?sticas topogr?ficas do NEB parecem desempenhar um papel importante na variabilidade observada na precipita??o, principalmente nestas ?reas costeiras. A intensifica??o do anticiclone aumenta a converg?ncia dos ventos al?sios na costa contribuindo para a ocorr?ncia de precipita??o observada ? barlavento do planalto da Borborema. Por outro lado, o aumento da subsid?ncia parece ser respons?vel pelos d?ficits de precipita??o observados ? sotavento. Tais condi??es mostraram-se t?picas durante o predom?nio do regime de leste sobre a regi?o tropical da Am?rica do Sul e o NEB, durante o qual ocorre uma diminui??o no fluxo de umidade proveniente da Amaz?nia.
32
Preece, Ellen P. "Suitability of coho salmon habitat in Maddox and Carpenter Creeks, Skagit Delta, Washington". Pullman, Wash. : Washington State University, 2010. http://www.dissertations.wsu.edu/Thesis/Spring2010/e_preece_060810.pdf.
Testo completoAbstract (sommario):
Thesis (M.S. in natural resource sciences)--Washington State University, May 2010.Title from PDF title page (viewed on July 19, 2010). "Department of Natural Resource Sciences." Includes bibliographical references (p. 43-47).
33
Monges, Arnaud C. "Impact of the Madden-Julian oscillation over tropical South America During Austral summer". Thesis, Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/25784.
Testo completo
34
Stepanek, Adam J. "North Pacific - North American circulation and precipitation anomalies associated with the Madden-Julian oscillation". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2006. http://library.nps.navy.mil/uhtbin/hyperion/06Mar%5FStepanek.pdf.
Testo completoAbstract (sommario):
Thesis (M.S. in Meteorology)--Naval Postgraduate School, March 2006.Thesis Advisor(s): Tom Murphree, Carlyle Wash. "March 2006." Includes bibliographical references (p.115-117). Also available online.
35
Remaud, Marine. "Impact de la paramétrisation convective sur la représentation de la variabilité intrasaisonnière tropicale". Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066681.
Testo completoAbstract (sommario):
L'Oscillation de Madden-Julian (MJO) est le principal mode de variabilité intrasaisonnière (20-90 jours) dans les tropiques. La MJO se caractérise par une perturbation de la dynamique de grande échelle et des précipitations se propageant principalement vers l'Est à une vitesse 5 m/s à l'équateur, et aussi vers le Nord en été boréal. Malgré son importance, cette perturbation est mal reproduite dans les modèles de circulation générale (MCG). Ce défaut des MCGs a été attribué en partie à un déclenchement trop fréquent du schéma de convection profonde du modèle qui préserverait trop la stabilité statique dans les tropiques et empêcherait la formation de fortes perturbations organisées de la convection et le développement de la réponse dynamique de grande échelle qui en résulte. Cette thèse a donc pour objectif d'étudier l'impact de l'inhibition de la convection sur l'état moyen et la variabilité tropicale dans le MCG LMDZ. Pour cela, deux paramètres - la fermeture et l'entraînement - d'un même schéma convectif, qui étaient initialement basés sur le profil vertical de la convergence d'humidité, ont été modifiés. Le taux entraînement du schéma modifié est proportionnel à l'humidité relative de l'environnement. Des études de sensibilité dans un modèle unidimensionnel montrent que, par rapport au schéma initial, cette modification a pour effet d'inhiber la convection dans une atmosphère sèche et de la favoriser en atmosphère humide, les précipitations deviennent donc plus rares et plus intenses. Avec ce nouvel entraînement, les simulations globales du modèle atmosphérique LMDZ présentent effectivement une plus forte variabilité tropicale de la dynamique et des précipitations à toutes les échelles de temps. Le cycle saisonnier des précipitations est aussi mieux reproduit ainsi que la propagation vers l'Est et vers le Nord des perturbations intrasaisonnières. L'ajout d'une fermeture en CAPE modifie peu ce comportement, mais accélère légèrement la propagation vers le Nord et vers l'Est de la MJO, et donne un état moyen et une variabilité un peu plus réaliste dans les tropiquesThe Madden-Julian oscillation (MJO) is the dominant mode of the Tropical intraseasonal variability. The MJO is characterized by a wide region of rain perturbation propagating eastward along the equator at a speed of about 5 m/s, from the Indian Ocean to the Central Pacific with a period of 20-90 days. Its boreal summer counterpart, referred as the Boreal Summer Intraseasonal Oscillation (BSISO), propagates both eastward and northward. The LMDZ atmospheric global circulation model (GCM), like most climate models, still has difficulties to represent correctly these two modes of tropical intraseasonal variability. One of the causes of this deficiency has been attributed to the lack of intense rain events organized at large scale. If the convection is triggered too easily in a GCM, the convective instability cannot accumulate in a column and trigger an organized convection at a basin scale. This thesis consisted in testing the role of several ways of inhibiting the convection in the simulation of the MJO in the LMDZ GCM. For this purpose, we have first evaluated the impact of entrainment and closure assumptions of the convective scheme on the structure of the atmospheric column using a 1D model and on the tropical variability using the LMDZ GCM. An entrainment that is dependant on the relative humidity of the environment has been implemented in the Tiedtke (1989) convective scheme. The new entrainment inhibits the convection in a dry environment and promotes the convection in a humid environment. This favours strong ascents and subsidence and consequently increases the variance of precipitation at all time scales. The new closure, based on the convective instability (CAPE) instead of the moisture convergence, decreases the occurrence of strong rain events and gives a more realistic mean state. The east-west ratio is increased at intraseasonal scale but it is not sufficient to organise correctly the eastward propagation related to the MJO. The seasonal cycle of the tropical precipitation over India is however improved. The LMDZ is able to reproduce correctly the signature of the northward propagation of the BSISO with a period of 40 days in Boreal Summer. We have shown, with A Local Mode Analysis (LMA), that the new entrainment produces intraseasonal perturbations related to the northward propagation of the BSISO which are more reproducible and more organized on the northern Indo-Pacific region
36
Kritis, Matt. "Natural dyes : thickening madder, weld, and woad for screenprinting of Turkish inspired textile prints". Thesis, Manhattan, Kan. : Kansas State University, 2010. http://hdl.handle.net/2097/3899.
Testo completo
37
Qu, Li. "Mading Lude lun lü fa yu fu yin = Martin Luther on law and gospel /". click here to view the fulltext click here to view the abstract and table of contents, 2004. http://net3.hkbu.edu.hk/~libres/cgi-bin/thesisft.pl?pdf=b17982182f.pdf.
Testo completo
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Widlansky, Matthew Johnson. "Variability of the South Pacific Convergence Zone and its influence on the general atmospheric circulation". Thesis, Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19766.
Testo completoAbstract (sommario):
Intense atmospheric convection associated with the South Pacific Convergence Zone (SPCZ) significantly impacts basin-scale circulation patterns over the Pacific. We explore dynamical processes which foster changes in convection along the convergence zone. These forcings include strong moisture convergence and accumulation of wave energy in the boundary layer, as well as dynamical instability associated with moderate cross-equatorial wind bursts. A focus is applied to observing the dominant modes of variability on synoptic to intraseasonal timescales using a combination of satellite observations and NCEP reanalysis data. Accumulation of energy, due to negative stretching deformation, occurs with both tropical and extratropical modes suggesting that the SPCZ is an artifact of wide ranging modes. Signals of the dominant modes (inferred from fields of outgoing longwave radiation: OLR) are isolated using bandpass filtering techniques, which are then mapped in space and time using Principal Components from Empirical Orthogonal Function analyses.
Variability of convective systems in the SPCZ is found to be significantly correlated with changes in the regional Hadley Circulation and the Pacific Walker cell. This co-variability presents the possibility of important teleconnection routes between the tropical West and East Pacific, as well as with the mid-latitude regions of the Northern and Southern Hemispheres. We test these interaction hypotheses by developing composites of the circulation patterns using dates of maximum convection events (regions of minimum OLR) in the SPCZ. Intensities of the large-scale circulations are measured using observations of stream function mass fluxes. Results suggest that deep convection maxima (minima) are associated with an increase (decrease) in the Walker Circulation. It is also illustrated how off-equatorial convection anomalies in the subtropical portion of the SPCZ may induce changes to the Hadley Circulation. Interactions with the zonal (Walker) and meridional (Hadley) circulations appear to have important consequences on the ability for wave energy to propagate through the tropical Pacific atmosphere. Examples include Northern Hemisphere cross-equatorial teleconnections through the Westerly Wind Duct in the upper branch of the Walker circulation and Rossby wave trains in the SPCZ, which may be partially governed by characteristics of the regional Hadley circulation.
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LIMA, Alexandra Amaro de. "A variabilidade da precipitação sobre a América do Sul tropi- cal associada a oscilações interanual e intrasazonal". Instituto Nacional de Pesquisas da Amazônia, 2015. http://bdtd.inpa.gov.br/handle/tede/2160.
Testo completoAbstract (sommario):
Submitted by Inácio de Oliveira Lima Neto (inacio.neto@inpa.gov.br) on 2016-08-29T14:31:20Z
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Intra-seasonal and inter-annual oscillations are responsible for part of precipitation ex- tremes during austral summer. In view of this, this study aimed to analyze the intra- seasonal variability modes on time scales of 8-24 days and 30-90 days associated with extreme events of daily precipitation over South America for 14 summer seasons, from 1998 to 2012. To achieve this we used a set of daily rainfall data from TRMM (Tropical Rainfaill Measuring Mission -NASA), stream functions and moisture fluxes obtained by NCEP Reanalysis - 2 (National Center for Environmental Prediction), with analysis of orthogonal functions, which made possible finding the three dominant modes on South America, and the Morlet wavelet transform to check for variations in the scales of 8- 24 and 30-90 days. Composite analyzes were used to assess the possible relation between the variability modes, when they operate separately and simultaneously. In parallel, we investigated possible interactions between intra-seasonal events on scales of 8-24 days during El Niño, La Nina and neutral years. The results indicated the domi- nance of intra-seasonal scales of 8-24 days on the continent compared to 30-90 days scale, especially when the events are in phase. The events operating in different pha- ses showed a weakening of the precipitation anomalies on scales 8-24 (positive) and 30-90 (negative) and when reversing the signs we note a disorganization of convection. The same is true during ENSO years. At the same time, it was found that during ENSO years the intra-seasonal scale is enhanced by the joint action of the extra-tropical and tropical wave-trains, and to the east of South America there is a predominance of intra- seasonal systems, while in the west rainfall anomalies are dominated by inter-annual variability.
As oscilações intrasazonais e interanuais são responsáveis por parte dos extremos de precipitação durante o verão autral. Diante disto, o presente trabalho teve como obje- tivo principal analisar os modos de variabilidade intrasazonais nas escalas de tempo de 8-24 dias e 30-90 dias associados aos eventos extremos de precipitação diária so- bre América do Sul durante 14 estações de verão, no período de 1998 a 2012. Para alcançar esse objetivo utilizou-se um conjunto de dados de diárias de precipitação do TRMM (Tropical Rainfaill Measuring Mission -NASA), função de corrente e fluxos de umidade obtidos pelo Reanálise - 2 do NCEP (National Centers for Environmen- tal Prediction), com análises de funções ortogonais, que possibilitou encontrar os três modos dominantes sobre a América do Sul, e a transformada de Ondeleta (Morlet) para verificar a existência de oscilações nas escalas de 8-24 e 30-90 dias. Análises de composições foram usadas para avaliar as possíveis relações entre as escalas de variabilidade, quando estas atuam isoladamente e simultaneamente. Paralelamente, buscou-se verificar possíveis interações entre os eventos intrasazonais na escala de 8-24 dias durante os anos de El Niño, La Nina e Neutro. Os resultados indicaram a predominância da escala intrasazonal de 8-24 dias sobre o continente em relação a escala de 30-90 dias, principalmente quando os eventos estão em fase. Os eventos atuando em fases diferentes mostraram um enfraquecimento das anomalias de preci- pitação nas escalas 8-24 (positiva) e 30-90 (negativa) e quando os sinais são inverti- dos, nota-se uma desorganização da convecção. O mesmo acontece durante o anos de atuação do ENOS. Ao mesmo tempo, verificou-se que durante os anos de ENOS a escala intrasazonal é intensificada pela ação conjunta do trem de ondas extratropical e tropical, e que ao leste da AS existe uma predominância dos sistemas intrasazonais, enquanto que à oeste as anomalias de precipitação são dominadas pela variabilidade interanual. Palavras-chave: Variabilidade Intrasazonal, Variabilidade Interanual, Oscilação Mad- den Julian, Teleconexão.
40
Mero, John C. "Under the influence has MADD's policy agenda limited the Elks' capability to create social capital? /". Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2009. http://wwwlib.umi.com/cr/syr/main.
Testo completo
41
Saun, Gabriel John. "Teachers' Perceptions of Behaviour Difficulties in Primary Schools: A Madang Province Perspective, Papua New Guinea". The University of Waikato, 2008. http://hdl.handle.net/10289/2342.
Testo completoAbstract (sommario):
Behavioural difficulty is probably the least understood area of special education as it is very problematic to identify a specific cause. Behavioural difficulties are those behaviours that students sometimes exhibit that are inappropriate and unacceptable in the classrooms or schools, as they disrupt the smooth process of teaching and learning. This study investigated primary school teachers' perspectives of the causal factors of students' behavioural problems and what can be done to minimise this problem. The study was carried out in the Madang Province involving two primary schools. From the two schools, twelve teachers (six from each school) participated in the study. The same participants were involved in both the questionnaire and the semi structured interview. The data gathered for the questionnaire and interview were analysed and transcribed respectively. The findings discovered that the family and school factors contributed substantially towards students' inappropriate behaviours. Family factors include parental problems, abuse in the families, and the constant struggle to provide the basic necessities due to the high living cost. School factors, on the other hand, include negative teacher attitudes, teacher lack of knowledge and skills to adapt the curriculum to include social skills, lack of teacher support and encouragement, and peer influences. The findings also discovered that teachers were more bothered about externalising behaviours such as disruption and aggression than internalising behavioural problems like withdrawal and depression displayed by students. Further, teachers' limited pre-service and in-service training and lack of experience in teaching students with behavioural problems contributed significantly for teachers not attending to students who behave inappropriately. Based on the findings identified in the study, several recommendations were made on how to intervene to alleviate this problem. Of particular importance is teacher training at both the pre-service and in-service level. Also government support is needed in terms of funding for training, involving specialists and other resources to respond to student behavioural problems effectively and efficiently. The findings may have particular relevance to future studies in this area and provide teachers with effective and workable intervention strategies for students' behavioural problems in the classrooms.
42
Peatman, Simon. "The Madden-Julian Oscillation and the diurnal cycle over the Maritime Continent : scale interactions and modelling". Thesis, University of East Anglia, 2014. https://ueaeprints.uea.ac.uk/48786/.
Testo completoAbstract (sommario):
The Maritime Continent archipelago, situated on the equator at 95-165E, has the strongest land-based precipitation on Earth. The latent heat release associated with the rainfall affects the atmospheric circulation throughout the tropics and into the extra-tropics. The greatest source of variability in precipitation is the diurnal cycle. The archipelago is within the convective region of the Madden-Julian Oscillation (MJO), which provides the greatest variability on intra-seasonal time scales: large-scale (∼10^7 km^2) active and suppressed convective envelopes propagate slowly (∼5 m s^-1) eastwards between the Indian and Pacific Oceans. High-resolution satellite data show that a strong diurnal cycle is triggered to the east of the advancing MJO envelope, leading the active MJO by one-eighth of an MJO cycle (∼6 days). Where the diurnal cycle is strong its modulation accounts for 81% of the variability in MJO precipitation. Over land this determines the structure of the diagnosed MJO. This is consistent with the equatorial wave dynamics in existing theories of MJO propagation. The MJO also affects the speed of gravity waves propagating offshore from the Maritime Continent islands. This is largely consistent with changes in static stability during the MJO cycle. The MJO and its interaction with the diurnal cycle are investigated in HiGEM, a high-resolution coupled model. Unlike many models, HiGEM represents the MJO well with eastward-propagating variability on intra-seasonal time scales at the correct zonal wavenumber, although the inter-tropical convergence zone's precipitation peaks strongly at the wrong time, interrupting the MJO's spatial structure. However, the modelled diurnal cycle is too weak and its phase is too early over land. The modulation of the diurnal amplitude by the MJO is also too weak and accounts for only 51% of the variability in MJO precipitation. Implications for forecasting and possible causes of the model errors are discussed, and further modelling studies are proposed.
43
Allen, Angela. "An investigation of the relationship between malaria and red-cell polymorphisms in Madang, Papua New Guinea". Thesis, Oxford Brookes University, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491312.
Testo completoAbstract (sommario):
In 1949, JBS Haldane proposed that the high frequency of the thalassaemias might reflect a heterozygote survival advantage against malaria. This 'malaria hypothesis' formed the basis for this programme of research. Between 1993 and 2006, I conducted a series of comprehensive and detailed studies of the relationships between malaria and the common red-cell variants a- thalassaemia and Southeast Asian ovalocytosis (SAO) in children and pregnant women in the North coastal region of Papua New Guinea. The clinical and laboratory features of malaria in children were described. In multiple regression analysis, raised plasma lactate (> 5mmolll) was the major predictor of death. Acidosis and impaired renal function were also independent predictors of mortality, and muscle-cell injury was identified as a cause of dark urine. A case-control study of 249 children admitted to hospital with severe malaria and 233 children with severe non-malaria illnesses was undertaken to investigate the possible protective effect of a+-thalassaemia and SAO against the severe manifestations of malaria and other severe illnesses. Homozygous a+thalassaemia reduced the risk of severe malaria by 60% and SAO appeared to provide complete protection against cerebral malaria. Interestingly, a+ thalassaemia also protected against hospital admission in children with nonmalarial illnesses. I investigated the frequencies of a+ -thalassaemia and SAO, and their relationship with malaria in pregnancy and pregnancy outcome, in over 900 women who delivered their babies in hospital. My findings suggest that neither a+ thalassaemia nor SAO protected against malaria in pregnancy or improved pregnancy outcome. During these studies, I identified the haematological and red-cell abnormalities most consistent with the band 3 deletion for SAO, which may be used to improve the diagnosis, where molecular methods are not available. The findings of the potent protection afforded by a+-thalassaemia and SAO against severe malaria in children will encourage further investigation of the underlying mechanisms. In turn, this may offer new approaches to the design of targeted interventions for the prevention and treatment of malaria that will improve the health of the millions of children who suffer from this devastating disease every year.
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Dickson, John. "A different model of doing business in a subsistance community : experience from Madang, Papua New Guinea". Thesis, Cranfield University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309683.
Testo completo
45
Hirons, Linda Catherine. "Understanding advances in the simulation of the Madden-Julian Oscillation in a numerical weather prediction model". Thesis, University of Reading, 2012. http://centaur.reading.ac.uk/57772/.
Testo completoAbstract (sommario):
The Madden-Julian Oscillation (MJO) is the dominant mode of intraseasonal variability in the Trop- ics. It can be characterised as a planetary-scale coupling between the atmospheric circulation and organised deep convection that propagates east through the equatorial Indo-Pacific region. The MJO interacts with weather and climate systems on a near-global scale and is a crucial source of predictability for weather forecasts on medium to seasonal timescales. Despite its global signifi- cance, accurately representing the MJO in numerical weather prediction (NWP) and climate models remains a challenge. This thesis focuses on the representation of the MJO in the Integrated Forecasting System (IFS) at the European Centre for Medium-Range Weather Forecasting (ECMWF), a state-of-the-art NWP model. Recent modifications to the model physics in Cycle 32r3 (Cy32r3) of the IFS led to ad- vances in the simulation of the MJO; for the first time the observed amplitude of the MJO was maintained throughout the integration period. A set of hindcast experiments, which differ only in their formulation of convection, have been performed between May 2008 and April 2009 to asses the sensitivity of MJO simulation in the IFS to the Cy32r3 convective parameterization. Unique to this thesis is the attribution of the advances in MJO simulation in Cy32r3 to the mod- ified convective parameterization, specifically, the relative-humidity-dependent formulation for or- ganised deep entrainment. Increasing the sensitivity of the deep convection scheme to environmen- tal moisture is shown to modify the relationship between precipitation and moisture in the model. Through dry-air entrainment, convective plumes ascending in low-humidity environments terminate lower in the atmosphere. As a result, there is an increase in the occurrence of cumulus congestus, which acts to moisten the mid-troposphere. Due to the modified precipitation-moisture relationship more moisture is able to build up which effectively preconditions the tropical atmosphere for the transition to deep convection. Results from this thesis suggest that a tropospheric moisture control on convection is key to simulating the interaction between the physics and large-scale circulation associated with the MJO.
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Burton, Gera. "Ambivalence in the colonized subject : the counter-discourse of Richard Robert Madden and Juan Francisco Manzano /". free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3052156.
Testo completo
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Kuznetsova, Daria. "Modélisation de l'oscillation Madden-Julian lors de son passage sur l'océan Indien et le continent maritime". Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30220/document.
Testo completoAbstract (sommario):
L'oscillation de Madden-Julian (MJO) est la composante dominante de la variabilité intrasaisonnière dans l'atmosphère tropicale, se propageant vers l'est dans la bande équatoriale. Elle se compose d'un centre convectif (phase active) accompagné de la convergence des anomalies du vent zonal de bas niveau et de la divergence de niveau supérieur, et de zones de convection faible (phases supprimées). Trois périodes de l'activité MJO sur l'océan Indien et le continent maritime ont été choisies : 6-14 avril 2009, 23-30 novembre 2011 et 9-28 février 2013. Les simulations avec et sans paramétrisation de la convection ont été réalisées pour un grand domaine avec le modèle atmosphérique Méso-NH. Il a été obtenu que les simulations avec convection paramétrée n'étaient pas capables de reproduire un signal MJO. Pour 2009 et 2011, lorsque le couplage entre la convection et la circulation de grande échelle était fort, les simulations avec convection explicite ont montré une propagation visible de la MJO, ce qui n'a pas été le cas pour 2013. Pour 2011, les processus contribuant à la suppression de la convection ont été étudiés avec une analyse isentropique pour séparer les masses d'air ascendantes ayant une température potentielle équivalente élevée des masses d'air subsidentes ayant une température potentielle équivalente faible. Trois circulations de grande échelle ont été trouvées : une circulation troposphérique, une circulation de percées nuageuses dans la couche de tropopause tropicale, et une circulation de masses d'air à faible température potentielle équivalente dans la basse troposphère. Cette dernière correspond aux intrusions d'air sec de grande échelle des zones subtropicales dans la bande équatoriale, trouvées principalement pendant la phase supprimée de la MJO sur l'océan IndienThe Madden-Julian Oscillation (MJO) is the dominant component of the intraseasonal variability in the tropical atmosphere, propagating eastward in the equatorial band. It consists of a convective center (active phase) accompanied by the low-level zonal wind anomaly convergence and the upper-level zonal wind anomaly divergence, and zones of weak convection (suppressed phases). Three time periods of the MJO activity over the Indian Ocean and the Maritime Continent were chosen: 6-14 April 2009, 23-30 November 2011, and 9-28 February 2013. The simulations with and without convective parameterizations were performed for a large domain with the atmospheric model Méso-NH. It was obtained that the simulations with parameterized convection were not able to reproduce an MJO signal. For 2009 and 2011 when the coupling between convection and large-scale circulation was strong, the convection-permitting simulations showed a visible MJO propagation, which was not the case for 2013. For the 2011 episode, the processes contributing to the suppression of the convection were studied using an isentropic analysis to separate the ascending air masses with high equivalent potential temperature from the subsiding air masses with low equivalent potential temperature. Three large-scale circulations were found: a tropospheric circulation, an overshoot circulation within the tropical tropopause layer, and a circulation of air masses with low equivalent potential temperature in the lower troposphere. The latter corresponds to the large-scale dry air intrusions from the subtropical zones into the equatorial band, mostly found during the suppressed MJO phase over the Indian Ocean
48
Remaud, Marine. "Impact de la paramétrisation convective sur la représentation de la variabilité intrasaisonnière tropicale". Electronic Thesis or Diss., Paris 6, 2015. http://www.theses.fr/2015PA066681.
Testo completoAbstract (sommario):
L'Oscillation de Madden-Julian (MJO) est le principal mode de variabilité intrasaisonnière (20-90 jours) dans les tropiques. La MJO se caractérise par une perturbation de la dynamique de grande échelle et des précipitations se propageant principalement vers l'Est à une vitesse 5 m/s à l'équateur, et aussi vers le Nord en été boréal. Malgré son importance, cette perturbation est mal reproduite dans les modèles de circulation générale (MCG). Ce défaut des MCGs a été attribué en partie à un déclenchement trop fréquent du schéma de convection profonde du modèle qui préserverait trop la stabilité statique dans les tropiques et empêcherait la formation de fortes perturbations organisées de la convection et le développement de la réponse dynamique de grande échelle qui en résulte. Cette thèse a donc pour objectif d'étudier l'impact de l'inhibition de la convection sur l'état moyen et la variabilité tropicale dans le MCG LMDZ. Pour cela, deux paramètres - la fermeture et l'entraînement - d'un même schéma convectif, qui étaient initialement basés sur le profil vertical de la convergence d'humidité, ont été modifiés. Le taux entraînement du schéma modifié est proportionnel à l'humidité relative de l'environnement. Des études de sensibilité dans un modèle unidimensionnel montrent que, par rapport au schéma initial, cette modification a pour effet d'inhiber la convection dans une atmosphère sèche et de la favoriser en atmosphère humide, les précipitations deviennent donc plus rares et plus intenses. Avec ce nouvel entraînement, les simulations globales du modèle atmosphérique LMDZ présentent effectivement une plus forte variabilité tropicale de la dynamique et des précipitations à toutes les échelles de temps. Le cycle saisonnier des précipitations est aussi mieux reproduit ainsi que la propagation vers l'Est et vers le Nord des perturbations intrasaisonnières. L'ajout d'une fermeture en CAPE modifie peu ce comportement, mais accélère légèrement la propagation vers le Nord et vers l'Est de la MJO, et donne un état moyen et une variabilité un peu plus réaliste dans les tropiquesThe Madden-Julian oscillation (MJO) is the dominant mode of the Tropical intraseasonal variability. The MJO is characterized by a wide region of rain perturbation propagating eastward along the equator at a speed of about 5 m/s, from the Indian Ocean to the Central Pacific with a period of 20-90 days. Its boreal summer counterpart, referred as the Boreal Summer Intraseasonal Oscillation (BSISO), propagates both eastward and northward. The LMDZ atmospheric global circulation model (GCM), like most climate models, still has difficulties to represent correctly these two modes of tropical intraseasonal variability. One of the causes of this deficiency has been attributed to the lack of intense rain events organized at large scale. If the convection is triggered too easily in a GCM, the convective instability cannot accumulate in a column and trigger an organized convection at a basin scale. This thesis consisted in testing the role of several ways of inhibiting the convection in the simulation of the MJO in the LMDZ GCM. For this purpose, we have first evaluated the impact of entrainment and closure assumptions of the convective scheme on the structure of the atmospheric column using a 1D model and on the tropical variability using the LMDZ GCM. An entrainment that is dependant on the relative humidity of the environment has been implemented in the Tiedtke (1989) convective scheme. The new entrainment inhibits the convection in a dry environment and promotes the convection in a humid environment. This favours strong ascents and subsidence and consequently increases the variance of precipitation at all time scales. The new closure, based on the convective instability (CAPE) instead of the moisture convergence, decreases the occurrence of strong rain events and gives a more realistic mean state. The east-west ratio is increased at intraseasonal scale but it is not sufficient to organise correctly the eastward propagation related to the MJO. The seasonal cycle of the tropical precipitation over India is however improved. The LMDZ is able to reproduce correctly the signature of the northward propagation of the BSISO with a period of 40 days in Boreal Summer. We have shown, with A Local Mode Analysis (LMA), that the new entrainment produces intraseasonal perturbations related to the northward propagation of the BSISO which are more reproducible and more organized on the northern Indo-Pacific region
49
Lohrstorfer, Christopher Lee. "Teaching Wesleyan theology a study of Wesleyan-related Bible colleges and Maddox's Responsible grace /". Theological Research Exchange Network (TREN), 1995. http://www.tren.com.
Testo completo
50
Maddox, Amrei [Verfasser], e Irena [Akademischer Betreuer] Kogan. "Parental influence on the ethnic partner choice within immigrant families in Europe / Amrei Maddox ; Betreuer: Irena Kogan". Mannheim : Universitätsbibliothek Mannheim, 2019. http://d-nb.info/1197143998/34.
Testo completo