<p>In this thesis, I combined comparative and experimental approaches to examine selection on reproductive traits and population differentiation in the insect-pollinated, self-incompatible, perennial herb <i>Primula farinosa</i>. More specifically, I (1) determined whether the effects of floral display and interactions with pollinators and seed predators, and plant reproductive success were frequency-dependent and affected by surrounding vegetation context, (2) examined the consequences of intermittent drought years on population dynamics using numerical simulations based on demographic data collected over seven years, (3) analyzed among-population differentiation in flowering phenology and reproductive allocation, and its relationship to soil-depth at the site of origin. </p><p>A field experiment suggested that conspicuous plants facilitate inconspicuous plants in terms of pollinator attraction, and that the facilitation effect is contingent on the height of the surrounding vegetation. Further experiments revealed that both mutualistic and antagonistic interactions can result in frequency-dependent selection on floral display. Among inconspicuous plants, both fruit initiation, and damage from seed predators increased with the proportion of the conspicuous morph. The relative strength of these effects, and therefore their net outcome on the relationship between morph ratio and seed production varied among years. </p><p>I combined information on vital rates and their relation to environmental conditions in simulations to predict future population viability in changing environments. Simulated stochastic population growth rate decreased with increasing frequency of drought years. </p><p>Reproductive allocation varied significantly among populations both in the field and in a common-garden experiment, but was correlated with soil depth at the site of origin only in the field. The results suggest that among-population variation in reproductive effort in the field mainly reflects plastic responses to environmental conditions, and that this plasticity may be adaptive. The common-garden experiment suggested that the study populations have diverged genetically in flowering time.</p>

The European rewardless orchid Dactylorhiza sambucina commonly produces yellow- and purple-flowered individuals in frequencies that in different populations range from balanced to very unbalanced ones (we can find even monochromatic populations). I studied an effect of abiotic factors (soil pH, hydrolimits, slope and altitude of the locality), biotic factors (weight and viability of the seeds obtained from crossing between and within morphs) and the size of the populations on corolla colour of two morphs in European populations (the Czech Republic, Italy, Austria, Germany, France).

Orientador: Marcus Aloizio Martinez de Aguiar / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-08-15T21:06:55Z (GMT). No. of bitstreams: 1 Andrade_ElizabethMachadoBaptestini_D.pdf: 4491574 bytes, checksum: 117d970a1c273ecd6ef9533aa742bb0f (MD5) Previous issue date: 2010 / Resumo: Nesse trabalho, estudamos doismecanismos de formação de espécies. No primeiro deles, consideramos um modelo espacial de especiação neutra totalmente probabilístico, sem barreiras geográficas ou interações ecológicas. A população evolui devido a influência de reprodução sexuada, mutações e recombinação. O modelo é baseado em acasalamento seletivo dependente de duas distâncias críticas, uma no espaço físico e outra no espaço dos genomas. Os vínculos introduzidos por essas duas distâncias permitem que a população se divida em grupos reprodutivamente isolados. Nossos resultados mostram que essa dinâmica gera padrões de diversidade consistentes com padrões observados na natureza, como distribuição de abundâncias do tipo log-normal, lei de potência para curvas espécie-área, taxas de especiação e extinção constantes e maior número de espécies para baixas dimensões. No segundo, nós generalizamos um modelo de especiação simpátrica baseado em competição intraespecífica, proposto por Dieckmann e Doebeli. Nesse modelo, uma população assexuada, inicialmente idêntica, evolui por seleção direcional para um fenótipo ótimo, onde a competição intraespecífica induz à seleção disruptiva. Nós mostramos que a forma das funções de competição e distribuição de recursos afetam a probabilidade de dois fenótipos coexistirem. Nós desenvolvemos um modelo analítico e simulações computacionais e comparamos os resultados de ambas abordagens / Abstract: In this work, we have studied two different mechanisms of species formation. In the first one, we considered a probabilistic spatial neutral model of speciation, without physical barriers or any kind of ecological interaction. The population evolves under the combined influences of sexual reproduction, mutation and recombination. The model is based on assortative mating and it depends on two critical distances, one in the genetic space and one in the physical space. The constraints imposed by these two distances allow the population to split in reproductively separated groups. Our results show that this kind of dynamics creates patterns of biodiversity in agreement with observed data, like lognormal distributions of species abundance, power law species-area relationships, steady speciation and extinctions rates and more species in low dimensions. In the second model, we generalized a sympatric speciation model based on intraspecific competition, proposed by Dieckmann and Doebeli. In that model, an assexual population, initially identical, evolves by directional selection to an optimal phenotype, where intraspecific competition induces disruptive selection. We show that the shape of the competition and carrying capacity kernels affects the likelihood of emergence of two coexisting phenotypes. We developed an analytical and a computational model and we compared the results of both approaches / Doutorado / Física da Matéria Condensada / Doutora em Ciências

The calculation of frequency-dependent cable parameters is essential for simulations of transient phenomena in electrical power systems. The simulation of transients is more complicated than the calculation of currents and voltages in the nominal frequency range. The model has to represent the frequency dependency and the wave propagation behavior of cable lines. The introduced model combines an improved subconductor method for the determination of the frequency-dependent parameters and a PI section wave propagation model. The subconductor method considers the skin and proximity effect in all conductors for frequency ranges up to few megahertz. The subconductor method method yields accurate results. The wave propagation part of the cable model is based on a cascaded PI section model. A modal transformation technique has been used for the calculation in the time domain. The frequency-dependent elements of the related modal transformation matrices have been fitted with rational functions. The frequency dependence of cable parameters has been reproduced using a vector fitting algorithm and has been implemented into an resistor-inductor-capacitor network (RLC network) for each PI section. The proposed full model has been validated with measured data.

The Nordic power system is in a changing phase, with more power electronic interfaced connections, and HVDC connections to other synchronous areas, which impacts the frequency quality. This is a challenge for the transmission system operator of Sweden, Svenska Kraftnät, who, with the other Nordic transmission system operators, is responsible for the physical balancing of the Nordic power system. To ensure that the grid can maintain stable operation when power imbalances or a disturbance occur, the frequency quality is important to evaluate. According to the current measurement of frequency quality, minutes outside of the standard frequency band, the frequency quality in the Nordic power system has been deteriorating. The current measurement does not capture what impact the frequency quality and needs to be redefined, with more precise measurements, for Svenska Kraftnät to be able to take necessary actions to ensure stability of the power system. Therefore, the purpose of this project is to determine which key performance indices, KPIs, can be used to develop the definition of frequency quality, and which system parameters are captured by the different KPIs. This project is executed with simulations in Matlab/Simulink to determine the impact five system parameters have on 15 different KPIs, and the results from the simulations are validated with historical data. The results indicate that all system parameters can be captured with KPIs, but after validation with historical data only two system parameters, which correlated with four KPIs, were deemed to be valid. The amount of FCR-N energy activated can be captured with the standard deviation of frequency, frequency area, and number of FCR-D activations. The kinetic energy can be captured by the standard deviation of RoCoF. The KPIs are recommended to be used to identify, and measure, the impact of new technical requirements for frequency control, and how the frequency stability is impacted by changes in the system. The conclusion is that four key performance indices are recommended to improve the definition of frequency quality, and further research is recommended to further define the concept of frequency quality. / För tillfället sker stora förändringar i det nordiska elsystemet. Fler produktionsanläggningar och industrier ansluts med kraftelektronik och fler HVDC-anslutningar byggs till andra synkronområden, vilket har stor inverkan på frekvenskvalitén. Detta leder till nya utmaningar för det svenska transmissionsnätets systemansvariga myndighet, Svenska Kraftnät, som gemensamt med sina nordiska motsvarigheter är ansvariga för den fysiska balanseringen i det nordiska synkronområdet. Det är viktigt att kontinuerligt följa upp frekvenskvalitén i transmissionsnätet så att stabil drift kan garanteras både vid mindre obalanser eller i händelse av större störningar. Det nuvarande nyckeltalet för uppföljning av frekvenskvalité, minuter utanför normalbandet, indikerar att frekvenskvalitén i det nordiska synkronområdet har blir sämre de senaste åren. Det nuvarande nyckeltalet indikerar inte vad som påverkar frekvenskvalitén och behöver omdefinieras med mer precisa nyckeltal för att Svenska Kraftnät ska kunna vidta nödvändiga åtgärder för att garantera en stabil drift av transmissionnätet. Syftet med examensarbetet är att definiera nya nyckeltal för att beskriva frekvenskvalité samt undersöka vilka systemparametrar som fångas av de olika nyckeltalen. I detta projekt har simuleringar utförts i Matlab/Simulink för att bestämma den inverkan fem olika systemparametrar har på 15 olika nyckeltal. Resultaten från simuleringar valideras med historisk data. Resultaten från simuleringen indikerar att de fem systemparametrarna kan fångas av olika kombinationer av de föreslagna nyckeltalen, men efter validering med historisk data bedöms enbart två systemparametrar fångas av totalt fyra nyckeltal. Systemparametern aktiverad FCR-N energi fångas av tre nyckeltal: frekvensens standardavvikelse, frekvensarea och antal FCR-D-aktiveringar. Systemparametern kinetisk energi fångas av ett nyckeltal: frekvensderivatans standardavvikelse. De fyra identifierade nyckeltalen kan användas för att identifiera och mäta hur frekvenskvalitén påverkas av nya tekniska krav, samt hur frekvensstabilitet påverkas av förändringar i systemet. Slutsatsen för detta projekt är att fyra nya nyckeltal rekommenderas för att utveckla definitionen av frekvenskvalité. Vidare arbete rekommenderas för att kunna utveckla begreppet vidare.

Within modern frequency structures, the filter frequency region of up to 10 MHz constitutes a promising research topic that currently attracts intensive attention of specialists interested in the problem. The main reason of this fact consists in that the rapid development of modern technology allows the production of innovated structures of the analog frequency filters required in the defined band. In this context, however, it is also necessary to refine the methods applied in the synthesis and optimization of these structures; such improvement should be carried out with respect to fundamental properties and usability of today's active elements (operational amplifiers with voltage feedback whose Gain Bandwidth Product ranges within units of GHz, operational amplifiers with current feedback, conveyors, transimpedance operational amplifiers). In this thesis, active blocks of synthesis inductors (SIs) and frequency dependent negative resistors (FDNRs) are examined in detail, and the author provides novel formulas to define the basic parameters of the dual circuits. Due emphasis was placed on optimizing the basic building blocks of the second order and defining the variation of their properties caused by the addition of modern active elements. The blocks were analyzed and modified in view of their possible use in higher-order circuits. For active filters of a higher order, simulations were performed to indicate the actual sensitivity of the cascade and non-cascade ARC structures. The following phase of the research comprised mainly the designing of several filters, and this activity was further completed with the verification of the methodology for the synthesis and optimization of higher-order loss ladder filters with modern active blocks. Special attention was paid also to the methods enabling the optimization of such filters, which are invariably based on RLC prototypes. In order to verify the theoretical conclusions, the author materialized a large number of sample optimized filters and measured their parameters. The closing section of the thesis describes the use of the filters in specific applications.

Cette thèse présente l'étude de la réduction de modèles pour les réseaux électriques et les réseaux de transmission. Un point de vue mathématique a été adopté pour la réduction de modèles. Les réseaux électriques sont des réseaux immenses et complexes, dont l'analyse et la conception nécessite la simulation et la résolution de grands modèles non-linéaires. Dans le cadre du développement de réseaux électriques intelligents (smart grids) avec une génération distribuée de puissance, l'analyse en temps réel de systèmes complexes tels que ceux-ci nécessite des modèles rapides,fiables et précis. Dans la présente étude, nous proposons des méthodes de réduction de de modèles à la fois a priori et a posteriori, adaptées aux modèles dynamiques des réseaux électriques.Un accent particulier a été mis sur la dynamique transitoire des réseaux électriques, décrite par un modèle oscillant non linéaire et complexe. La non-linéarité de ce modèle nécessite une attention particulière pour bénéficier du maximum d'avantages des techniques de réduction de modèles.Initialement, des méthodes comme POD et LATIN ont été adoptées avec des degrés de succès divers. La méthode de TPWL, qui combine la POD avec des approximations linéaires multiples, a été prouvée comme étant la méthode de réduction de modèles la mieux adaptée pour le modèle dynamique oscillant.Pour les lignes de transmission, un modèle de paramètres distribués en domaine fréquentiel est utilisé. Des modèles réduits de type PGD sont proposés pour le modèle DP des lignes de transmission. Un problème multidimensionnel entièrement paramétrique a été formulé, avec les paramètres électriques des lignes de transmission inclus comme coordonnées additionnelles de la représentation séparée. La méthode a été étendue pour étudier la solution du modèle des lignes de transmission pour laquelle les paramètres dépendent de la fréquence. / This thesis presents the study of the model order reduction for power grids and transmission networks. The specific focus has been the transient dynamics. A mathematical viewpoint has been adopted for model reduction. Power networks are huge and complex network, simulation for power grid analysis and design require large non-linearmodels to be solved. In the context of developing “SmartGrids” with the distributed generation of power, real time analysis of complex systems such as these needs fast,reliable and accurate models. In the current study we propose model order reduction methods both a-priori and aposteriori suitable for dynamic models of power grids.The model that describes the transient dynamics of the power grids is complex non-linear swing dynamics model. The non-linearity of the swing dynamics model necessitates special attention to achieve maximum benefit from the model order reduction techniques. In the current research, POD and LATIN methods were applied initially with varying degrees of success. The method of TPWL has been proved as the best-suited model reduction method for swing dynamics model ; this method combines POD with multiple linear approximations.For the transmission lines, a distributed parameters model infrequency-domain is used. PGD based reduced-order models are proposed for the DP model of transmission lines. A fully parametric problem with electrical parameters of transmission lines included as coordinates of the separated representation. The method was extended to present the solution of frequency-dependent parameters model for transmission lines.

No description available.

電気鉄道の安全安定輸送を確保するため，雷害防止が求められている。本論文では，電気鉄道設備の雷サージ特性実測を行い，接地インピーダンス特性を雷サージの視点から検討した。さらに，電力系統解析技術を応用して鉄道特有機器の回路解析モデルを開発し，その精度を実測で確認し，鉄道設備雷電流侵入時の応答を実測および計算結果より明らかにした。これらの成果は，電気鉄道の設計・保守・解析に十分に生かすことが可能である。 / Lightning protection is required to ensure safe and stable electric railway transportation. In this thesis, the lightning surge characteristics of the facilities in electric railway systems were measured. The characteristic of earthing impedance was also investigated from the viewpoint of lightning surge. In addition, some numerical models of railway specific apparatuses for circuit analysis method were developed by applying simulation technology for power system and confirmed their accuracies by actual measurements. The responses to lightning currents invaded into the facilities were clarified by the measured and calculated results. These results can be fully utilized in the design, maintenance and analysis of electric railway systems. / 博士(工学) / Doctor of Philosophy in Engineering / 同志社大学 / Doshisha University

This thesis deals with the synthesis and optimization of frequency analogue filters with modern active elements usable for higher frequencies. The thesis is divided into three parts, the first part deals with the problematic concerning Leap-Frog combined ARC structure. Due to a difficult design, this method is not described in a detail and used in practice, although it shows e.g. low sensitivity. Firstly, a complete analysis of individual filters was made (for and T endings) and consequently these findings were used during implementation of this method to NAF program. Finally, samples of real filters were realized (for verification of functioning and correct design). Another very interesting topic concerning filters is usage of coupled band-pass for small bandwidth, where it is necessary to solve the problems concerning ratio of building elements values, but also price, quality, size of coils, sensitivity, Q factors, coefficients etc. That is why in practice a coil is very often substituted with other equivalent lossy and lossless blocks which create ARC filters structure. The design and the possibility of usage of lossy grounded elements were described here (such as synthetic inductors, frequency dependent negative resistor). Some parts of the design are individual computer sensitivity analysis, setting of usage and quality comparison of individual lossy grounded blocks. Besides, a program for these elements was created, it is useful for a quick design and depiction of transfer characteristics. The third part deals with the usage of tuning universal filters consisting three or more operational amplifiers, which secures its universality and possibility to create different kinds of transfer characteristic. In practice, Akerberg - Mossberg and Kerwin - Huelsman - Newcomb are the most used types of filters. These were also compared with less common universal filters. In the end, the possibility of digital tuning of universal filter with the help of digital potentiometers for filters of 10th order and frequency around 1 MHz was shown.