This thesis consists of four chapters. Chapter 1 focuses on theoretical results on high-order laplacian-based regularization in function estimation. We studied the iterated laplacian regularization in the context of supervised learning in order to achieve both nice theoretical properties (like thin-plate splines) and good performance over complex region (like soap film smoother). In Chapter 2, we propose an innovative static path-planning algorithm called m-A* within an environment full of obstacles. Theoretically we show that m-A* reduces the number of vertex. In the simulation study, our approach outperforms A* armed with standard L1 heuristic and stronger ones such as True-Distance heuristics (TDH), yielding faster query time, adequate usage of memory and reasonable preprocessing time. Chapter 3 proposes m-LPA* algorithm which extends the m-A* algorithm in the context of dynamic path-planning and achieves better performance compared to the benchmark: lifelong planning A* (LPA*) in terms of robustness and worst-case computational complexity. Employing the same beamlet graphical structure as m-A*, m-LPA* encodes the information of the environment in a hierarchical, multiscale fashion, and therefore it produces a more robust dynamic path-planning algorithm. Chapter 4 focuses on an approach for the prediction of spot electricity spikes via a combination of boosting and wavelet analysis. Extensive numerical experiments show that our approach improved the prediction accuracy compared to those results of support vector machine, thanks to the fact that the gradient boosting trees method inherits the good properties of decision trees such as robustness to the irrelevant covariates, fast computational capability and good interpretation.

No description available.

Cette thèse explore l'analyse de l'activité électrique du cerveau. Un défi important de ces signaux est leur grande variabilité à travers différents essais et/ou différents sujets. Nous proposons une nouvelle méthode appelée "adaptive waveform learning" (AWL). Cette méthode est suffisamment générale pour permettre la prise en compte de la variabilité empiriquement rencontrée dans les signaux neuroélectriques, mais peut être spécialisée afin de prévenir l'overfitting du bruit. La première partie de ce travail donne une introduction sur l'électrophysiologie du cerveau, présente les modalités d'enregistrement fréquemment utilisées et décrit l'état de l'art du traitement de signal neuroélectrique. La principale contribution de cette thèse consiste en 3 chapitres introduisant et évaluant la méthode AWL. Nous proposons d'abord un modèle de décomposition de signal général qui inclut explicitement différentes formes de variabilité entre les composantes de signal. Ce modèle est ensuite spécialisé pour deux applications concrètes: le traitement d'une série d'essais expérimentaux segmentés et l'apprentissage de structures répétées dans un seul signal. Deux algorithmes sont développés pour résoudre ces problèmes de décomposition. Leur implémentation efficace basée sur des techniques de minimisation alternée et de codage parcimonieux permet le traitement de grands jeux de données.Les algorithmes proposés sont évalués sur des données synthétiques et réelles contenant des pointes épileptiformes. Leurs performances sont comparées à celles de la PCA, l'ICA, et du template-matching pour la détection de pointe. / This thesis investigates the analysis of brain electrical activity. An important challenge is the presence of large variability in neuroelectrical recordings, both across different subjects and within a single subject, for example, across experimental trials. We propose a new method called adaptive waveform learning (AWL). It is general enough to include all types of relevant variability empirically found in neuroelectric recordings, but can be specialized for different concrete settings to prevent from overfitting irrelevant structures in the data. The first part of this work gives an introduction into the electrophysiology of the brain, presents frequently used recording modalities, and describes state-of-the-art methods for neuroelectrical signal processing. The main contribution of this thesis consists in three chapters introducing and evaluating the AWL method. We first provide a general signal decomposition model that explicitly includes different forms of variability across signal components. This model is then specialized for two concrete applications: processing a set of segmented experimental trials and learning repeating structures across a single recorded signal. Two algorithms are developed to solve these models. Their efficient implementation based on alternate minimization and sparse coding techniques allows the processing of large datasets. The proposed algorithms are evaluated on both synthetic data and real data containing epileptiform spikes. Their performances are compared to those of PCA, ICA, and template matching for spike detection.

Les champs électriques pulsés sont largement utilisés dans la recherche, la médecine, l'industrie alimentaire et d'autres procédés biotechnologiques. L'interaction d'une impulsion de 100 µs avec la membrane plasmique et la membrane du réticulum endoplasmique a été évaluée dans deux types cellulaires différents. La perméabilisation des organites cellulaires avec ce type d'impulsions est démontrée expérimentalement pour la première fois. L'utilisation d'une telle impulsion afin de contrôler les oscillations calciques spontanées dans les cellules souches mésenchymateuses humaines issues du tissu adipeux a été évaluée. En créant des pics calciques électro-induits d’amplitudes différentes, l'impulsion peut ou bien induire un pic calcique supplémentaire ou bien inhiber les oscillations spontanées pour quelques dizaines de minutes. Cette inhibition rend possible d’imposer à la cellule des pics d’amplitude et de fréquence désirés. Un essai d’application de l'impulsion 100 µs à des cellules souches subissant une différenciation osseuse a aussi été réalisé. Une impulsion électrique semble retarder la différenciation. Lors d'une différenciation osseuse, plusieurs couches cellulaires ont été observées. La caractérisation de ces couches a donné des résultats qui pourraient aider à obtenir des ostéoblastes matures dans un temps moindre que la normale. L'utilisation des champs électriques pulsés microsecondes, pour perméabiliser la membrane plasmique et les membranes internes des cellules, ainsi que pour moduler les concentrations du calcium intracellulaire, semble donc très intéressante pour étudier le rôle du calcium dans de nombreux processus physiologiques et pour manipuler les dynamiques calciques (oscillations, vagues, pics) dans différents types de cellules. Ainsi, cette technologie simple, facile à appliquer et disponible dans beaucoup de laboratoires serait envisageable pour la modulation et le contrôle de fonctions cellulaires basiques telles que la prolifération, la différenciation et l'apoptose. / Pulsed electric fields are widely used in research, medicine, food industry and other biotechnological processes. The interaction of one 100 µs pulse with the plasma membrane and the endoplasmic reticulum membrane was evaluated in two different cell types. Pulse amplitude ranged between 100 and 3 000 V/cm. Organelles membrane permeabilization using this kind of pulses was experimentally demonstrated for the first time. The use of such a pulse to control the spontaneous calcium oscillations in human-adipose mesenchymal stem cells was also assessed. By creating electro-induced calcium spikes of different amplitudes, the pulse can either add a supplementary spike, or, on the contrary, inhibit the spontaneous oscillations for some tens of minutes. During this inhibition period, the electric pulse-mediated addition of calcium spikes of desired amplitude and frequency is still possible. The delivery of 100 µs pulses to stem cells undergoing osteodifferentiation was also performed. The electric pulse seemed to delay the differentiation. Moreover, during osteogenic differentiation, cells cultures displayed an organization in a few cell layers. The characterization of these layers gave results that may help to obtain mature osteoblast in less time than usual one. The use of the microsecond electric pulses technology to permeabilize the plasma and the internal cell membranes as well as to modulate internal calcium concentrations is therefore interesting to study the role of calcium in many physiological processes and to manipulate the cell calcium dynamics (oscillations, waves, spikes) in different cell types. Doing so, this available, simple and easy to apply technology could be used for the modulation and the control of basic cellular functions such as proliferation, differentiation and apoptosis.

Background and aim The pace of development of distance running shoes has been fast-forward since 2016 when Nike introduced their model Nike Zoom Vaporfly, with an imbedded carbon fiber plate and an advanced newly developed Pebax®-foam. The shoe-development has continued to track events, with the introduction of carbon fiber plate in several shoe-models for running and sprint- events. The research area for track events has not reached the level as for distance running shoes, therefore the aim of this study was to examine the effects on long jump performance when using long jump spikes with (AFT) compared to without (non-AFT) a carbon fiber plate.  Method Nine experienced male (n=6, age 22 ± 4.8 years, body mass 76.4 ± 3.5 kg, height 182 ± 4.9 cm), and female (n=3, age 20.3 ± 3.5 years, body mass 64.8 ± 6.0 kg, height 172 ± 2.0 cm) Swedish long jumpers performed three maximal effort long jumps in AFT and non-AFT long jump shoes. Three-dimensional kinematic data was captured with eight markerless motion capture cameras, and the take-off was performed from a force plate. Run-up velocity was measured using a lidar laser and step characteristics using an optical contact grid. Pearson’s correlation coefficient was calculated for jump distance and maximal run-up velocity and paired samples t-tests and a Wilcoxon rank sum test were conducted to examine differences between the shoes.  Results Peak run-up velocity correlated with jump distance both for AFT (Pearson’s r=0.919, p<0.001) and non-AFT shoes (Pearson’s r=0.910, p<0.001). At a group-level no statistical differences were found between the shoes for the run-up variables. The AFT shoes showed significantly greater horizontal velocity at touchdown (p=0.046) and vertical velocity difference from touchdown to toe-off (p=0.029) compared to the non-AFT shoes. No other significant difference was found on group level for the take-off variables. Conclusion The results in this study did not show a longer jump distance in long jump specific AFT shoes compared to non-AFT on a group level, but individual differences were seen. To further understand the effect of AFT shoes on long jump performance, more studies on different individual characteristics and their relation to long jump performance is needed. Keywords Long jump, super spikes, AFT-shoes, carbon fiber plate, biomechanics. / Bakgrund och syfte Sedan Nike 2016 introducerade sin skomodell Nike Zoom Vaporfly har utvecklingen av löparskor med en inbäddad kolfiberplatta och nyutvecklade med energiåtergivande material snabbt fortskridit. Utvecklingen av skor har fortsatt från löparspåren till friidrottsbanan för flera grenar. Forskningsområdet för grenspecifika skor har inte kommit lika långt som för distanslöparskor, därför var syftet med denna studie att undersöka effekterna på längdhoppsprestation av att använda längdhoppsspecifika spikskor med (AFT) jämfört med utan (non-AFT) kolfiberplatta. Metod Nio erfarna manliga (n=6, ålder 22 ± 4,8 år, kroppsvikt 76,4 ± 3,5 kg, längd 182 ± 4,9 cm) och kvinnliga (n=3, ålder 20,3 ± 3,5 år, kroppsvikt 64,8 ± 6 kg, längd 172 ± 2 cm) svenska längdhoppare gjorde tre maximala längdhopp i AFT och non-AFT längdhoppsskor. Tredimensionell kinematisk data samlades in med åtta markörlösa motion capture-kameror och uthoppet skedde från en kraftplatta. Ansatshastigheten mättes med en laserkamera och steg-specifik data med ett optiskt kontaktnät. Pearson’s korrelations koefficient beräknades for hopplängd och maximal ansatshastighet samt så genomfördes paired samples t-test och Wilcoxon rank sum test för att undersäka skillnaderna mellan skorna. Resultat Maximal ansatshastighet korrelerade med maximal hopplängd både för AFT skor (Pearsons r=0,919, p<0,001) och non-AFT skor (Pearsons r=0,910, p<0,001). På gruppnivå hittades ingen statistisk skillnad mellan skorna vad gäller ansatslöpningens variabler. AFT skorna visade en signifikant högre horisontell hastighet vid första markkontakt med kraftplatta (p=0,046) och vertikal hastighetsdifferens från första markkontakt med kraftplatta till sista markkontakt med kraftplatta (p=0,029) jämfört med non-AFT-skor. Ingen annan signifikant skillnad hittades på gruppnivå vad gäller uthoppsvariabler. Slutsats Resultaten i denna studie visade inte på en längre hopplängd i längdhoppsspecifika AFT skor jämfört med icke-AFT skor på gruppnivå men skillnader sågs på individnivå. För att ytterligare förstå effekten av AFT skor på längdhoppsprestation behövs fler studier om olika individuella egenskaper och dess relation till längdhoppsprestation. Nyckelord Längdhopp, super spikes, AFT-skor, karbonfiberplatta, biomekanik.

Made available in DSpace on 2016-04-28T14:59:00Z (GMT). No. of bitstreams: 1 Rejane Escrivani Guedes.pdf: 2537678 bytes, checksum: fa415f1591e33c3b7c367223fc134c67 (MD5) Previous issue date: 2008-03-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Cowpea genotypes submitted to organic management were evaluated for grain yield and green manure, as well as intercropped with corn, under field conditions of Serop?dica, state of Rio de Janeiro. In the year of 2005, 53 cowpea genotypes were compared at the Integrated Agroecology Produc tion System ( SIPA Km 47 Agroecologic Farm) relating to qualitative and quantitative agronomic traits. Data were treated by following univariate and multivariate statistical analysis. Significant differences were detected with respect to all the evaluated parameters. Genotypes EES-02, EES-08, EES-26, EES47, Feij?o-Caupi and Feij?o Mau? showed favourable attributes for immature (=green) grain yield. They presented determinate growth habit with moderate branchding and flowering stage up to 45 days after sowing, only differing by pod and grain colors. Univariete analysis demonstrated high variability among cowpea genotypes. However, multivariate analysis was more efficient to joint selected agronomic traits for identification of genotyp ic groups, which can be important in cowpea breeding programs. Cowpea and corn intercrops also submitted to organic cultivation were evaluated by means of two field experiments carried out at SIPA. In Experiment 1, the cowpea cultivars Mau?, BRS Mil?nio and Olho de Peixe were intercropped with corn (cv. AG-1051) to function as green manures. A randomized blocks design was employed in factorial 2x3 scheme (two corn plant spacing x three cowpea cultivars). In Experiment 2, Mau? cowpea and AG-1051 corn were intercropped for harvesting immature (=green) grains and spikes, respectively. Treatments consisted of four time intervals between cowpea and corn sowing. As for Experiment 1, corn planted in double rows favoured cowpea aboveground biomass production, probably due to a greater amount of light admitted into the system. Results from Experiments 2 indicated that intercrop with cowpea did not decrease corn yield which reached averages of 9,5 and 5,9 Mg ha-1 of ears with and without straw, respectively. Regarding cowpea grain yield of Mau? cultivar its single crop was superior to the intercrops exceeding 1400 kg ha-1. Treatment corresponding to 21 days of interval between cowpea and corn sowing differed from the other types of intecrops, with yield attaining 978,75 ka ka-1. It is concluded that the intercropping system can se adopted in the region without risks of lowering corn yield due to competition, being three weeks (21 days) the most adequate time interval between sowing. / Foi avaliado, em sistema org?nico de produ??o, o desempenho de gen?tipos de feij?o-caupi com potencial para produ??o de gr?os verdes e aduba??o verde, e em cons?rcios com o milho, nas condi??es da Baixada Fluminense, munic?pio de Serop?dica, estado do Rio de Janeiro. No ano de 2005, em ?rea do SIPA, (Sistema Integrado de Produ??o Agroecol?gica Fazendinha Agroecol?gica Km. 47 ), foram avaliados 53 gen?tipos de feij?o-caupi, segundo caracter?sticas fitot?cnicas qualitativas e quantitativas. Os dados foram submetidos a an?lise de vari?ncia univariada e a an?lise multivariada. Houve diferen?a significativa para todos os par?metros avaliados. Os gen?tipos EES-02, EES-08, EES-26, EES-47, Feij?o-Caupi e Feij?o Mau? reuniram caracter?sticas mais adequadas para colheita de gr?os verdes, apresentando porte semi-ramador, h?bito de crescimento determinado, com florescimento at? 45 dias ap?s semeadura, diferindo apenas pela colora??o da vagem e do gr?o. Os resultados da an?lise univariada demonstraram alta variabilidade entre os gen?tipos. Por?m, para o caso de se reunir v?rios atributos fitot?cnicos, constituindo grupos de gen?tipos, a an?lise multivariada se mostrou mais eficiente e pode ser de valia para o melhoramento do feij?o-caupi. Foi avaliado, ainda, o desempenho agron?mico dos cons?rcios do milho com o feij?o-caupi submetidos ao manejo org?nico, atrav?s de dois experimentos conduzidos no SIPA. No Experimento 1, avaliou-se o desempenho de tr?s cultivares de feij?o-caupi para aduba??o verde do milho (cv. AG-1501) em cons?rcios simult?neos. As cultivares de feij?o-caupi Mau?, BRS Mil?nio e Olho de Peixe foram utilizadas, adotando-se delineamento de blocos ao acaso, em esquema fatorial 2 x 3 (dois espa?amentos de milho e tr?s cultivares de feij?ocaupi). No Experimento 2, avaliou-se o cons?rcio entre feij?o-caupi (cv. Mau?) e milho (cv. AG-1051) para colheitas de gr?os verdes e de espigas verdes, respectivamente. Os tratamentos constaram de quatro intervalos entre as semeaduras de feij?o-caupi e de milho. No Experimento 1, o espa?amento do milho em fileiras duplas favoreceu a produ??o de biomassa a?rea fresca de feij?o-caupi, muito provavelmente pela maior entrada de luz no sistema. Os resultados do Experimento 2 indicaram que o cons?rcio n?o interferiu na produtividade do milho, colhendo-se, em m?dia, 9,5 e 5,9 Mg ha-1 de espigas verdes empalhadas e desempalhadas, respectivamente. Com rela??o ? produ??o de gr?os verdes da cv. Mau? de feij?o-caupi, o monocultivo superou os cons?rcios com o milho, ultrapassando 1400 kg ha-1. O cons?rcio correspondente a 21 DAM (dias antes do milho) diferiu dos demais tipos de cons?rcio, sendo superior, em produ??o, que atingiu 978,75 kg ha-1. Concluiu-se que o sistema de cons?rcio com o feij?o-caupi pode ser adotado na regi?o sem risco de perdas na produtividade do milho por efeito de competi??o, sendo de tr?s semanas (21 DAM) o intervalo mais adequado entre as semeaduras.

This thesis presents a collection of papers that has been published, accepted or submitted for publication. They assess price, volatility and market relationships in the five regional electricity markets in the Australian National Electricity Market (NEM): namely, New South Wales (NSW), Queensland (QLD), South Australia (SA), the Snowy Mountains Hydroelectric Scheme (SNO) and Victoria (VIC). The transmission networks that link regional systems via interconnectors across the eastern states have played an important role in the connection of the regional markets into an efficient national electricity market. During peak periods, the interconnectors become congested and the NEM separates into its regions, promoting price differences across the market and exacerbating reliability problems in regional utilities. This thesis is motivated in part by the fact that assessment of these prices and volatility within and between regional markets allows for better forecasts by electricity producers, transmitters and retailers and the efficient distribution of energy on a national level. The first two papers explore whether the lagged price and volatility information flows of the connected spot electricity markets can be used to forecast the pricing behaviour of individual markets. A multivariate generalised autoregressive conditional heteroskedasticity (MGARCH) model is used to identify the source and magnitude of price and volatility spillovers within (intra-relationship) and across (inter-relationship) the various spot markets. The results show evidence of the fact that prices in one market can be explained by their own price lagged one-period and are independent of lagged spot prices of any other markets when daily data is employed. This implies that the regional spot electricity markets are not fully integrated. However, there is also evidence of a large number of significant ownvolatility and cross-volatility spillovers in all five markets indicating that shocks in some markets will affect price volatility in others. Similar conclusions are obtained when the daily data are disaggregated into peak and off-peak periods, suggesting that the spot electricity markets are still rather isolated. These results inspired the research underlying the third paper of the thesis on modelling the dynamics of spot electricity prices in each regional market. A family of generalised autoregressive conditional heteroskedasticity (GARCH), RiskMetrics, normal Asymmetric Power ARCH (APARCH), Student APARCH and skewed Student APARCH is used to model the time-varying variance in prices with the inclusion of news arrival as proxied by the contemporaneous volume of demand, time-of-day, day-of-week and month-of-year effects as exogenous explanatory variables. The important contribution in this paper lies in the use of two latter methodologies, namely, the Student APARCH and skewed Student APARCH which take account of the skewness and fat tailed characteristics of the electricity spot price series. The results indicate significant innovation spillovers (ARCH effects) and volatility spillovers (GARCH effects) in the conditional standard deviation equation, even with market and calendar effects included. Intraday prices also exhibit significant asymmetric responses of volatility to the flow of information (that is, positive shocks or good news are associated with higher volatility than negative shocks or bad news). The fourth research paper attempts to capture salient feature of price hikes or spikes in wholesale electricity markets. The results show that electricity prices exhibit stronger mean-reversion after a price spike than the mean-reversion in the normal period, suggesting the electricity price quickly returns from some extreme position (such as a price spike) to equilibrium; this is, extreme price spikes are shortlived. Mean-reversion can be measured in a separate regime from the normal regime using Markov probability transition to identify the different regimes. The fifth and final paper investigates whether interstate/regional trade has enhanced the efficiency of each spot electricity market. Multiple variance ratio tests are used to determine if Australian spot electricity markets follow a random walk; that is, if they are informationally efficient. The results indicate that despite the presence of a national market only the Victorian market during the off-peak period is informationally (or market) efficient and follows a random walk. This thesis makes a significant contribution in estimating the volatility and the efficiency of the wholesale electricity prices by employing four advanced time series techniques that have not been previously explored in the Australian context. An understanding of the modelling and forecastability of electricity spot price volatility across and within the Australian spot markets is vital for generators, distributors and market regulators. Such an understanding influences the pricing of derivative contracts traded on the electricity markets and enables market participants to better manage their financial risks.

No description available.

Often perceived as pests, pigeon control is applied without investigating environmental, ecological and anthropogenic factors which affect their populations and response to controls. Estate Management of the University of South Africa’s Muckleneuk campus identified a need to investigate and address a perceived pigeon problem. Staff perceptions regarding the presence and attitude towards control of the pigeons was undertaken through an online Survey Monkey questionnaire and semi- structured interviews until saturation was achieved. It was determined that the a s sumed negative perception towards the pigeons was in fact incorrect. Participants would rather encourage the nesting and breeding activities of pigeons on campus, as they felt that the human–pigeon interactions and viewing of squabs in nests contributed positively to their work environment. Participants did not consider the pigeons or their related activities to pose a problem. It was felt that should control be imposed, the birds should rather be humanely managed through non-lethal measures rather than eradication. Pigeon numbers on five buildings on the University’s campus were counted at dawn and dusk, every week, for two years. The first year provided baseline data and the second year was when control measures were applied. The study determined that the pigeon population index fluctuated seasonally while breeding occurred throughout the year, with notable peaks and declines relating to physiological and population dynamics. The pigeons seemed to make opportunistic use of crop availability in surrounding farmlands during optimal production periods, while conserving energy when not favourable. Site selection in relation to building aspect indicated significant differences in all the seasons except for winter, while a positive significant relationship between level height and pigeon number was recorded. Once the control measures were applied, the total pigeon index on the campus declined by 50%. Control structures differed significantly in efficacy. Bird spikes indicated the highest efficacy at reducing the pigeon population index and seasonality did influence this efficiency. Birds of prey and an audio bird scarer were used to compare actual versus implied predator presence, it was determined that there was an association between method of scaring and the number of pigeons observed on the different time periods. Pigeons were observed to continue the natural trend of dispersion and return at the dawn and dusk counts during the audio bird scarer trial without being actively discouraged or dislodged from the building. Pigeons reacted positively to the visual raptor presence, which caused them to take flight from the buildings. The visual effect was only temporary however as pigeons returned once the threat had been removed 10 minutes post scare. The studies concluded in an interdisciplinary management plan presented to the University Estates. / Environmental Science / M. Sc. (Environmental Science)

The aim of my thesis is to assess the basic yield factors in the studied varieties of spring wheat. In the year 2013, there were in the framework of the test sown eight varieties (Brawura, Corso, Epos, Granny, Scirocco, Septima, Tercie and Vánek) at the land of the Faculty of Agriculture, University of South Bohemia in Ceske Budejovice. During the vegetation the number of plants, the number of sprouts and the number of spikes was recorded using a quarter tape. The data are in the results section and are converted to 1 m2. Additionally, the infestation by diseases, pests and overrunning with weeds was monitored. Before harvesting, the samples were taken for an evaluation of the number of grains per spike and HTZ. In the results section the main factors of the yield are statistically evaluated. These include the number of spikes, the number of grains per spike and HTZ. The study also evaluates the theoretical and the actual yield and the bulk density. The average number of ears in the varieties of spring wheat ranged from 411 (Corso) to 564 (Epos) ears per 1 m2. The number of grains per spike of individual varieties reached higher values, from 39,6 (Scirocco) to 57,8 (Corso). The average HTZ for the individual varieties was between 34,9 and 43,5 g. At finding of the real yield there were observed values from 3,4 t.ha-1 (Septima) to 4,5 t.ha-1 (Scirocco). The difference between the yield elements of were statistically significant all varieties.