A significant body of research has focused on tracking behaviors of predators responding to prey odor plumes, yet little is known about the specific mechanisms by which predators make decisions during tracking that lead them to a source. This dissertation advances the current knowledge of plume tracking behavior by examining blue crab tracking behavior over a large range of bed-roughnesses (thereby manipulating ambient levels of turbulence), and interpreting these results with respect to chemical signal structure derived from separate examinations of plume characteristics as determined by planar laser induced fluorescence (PLIF). Foraging success and the speed of blue crabs attempting to locate the odorant source both decline consistently with increasing bed roughness. In contrast, steering (path linearity) appears unaffected by bed roughness induced turbulence. The spatial arrangement of blue crab chemosensors combined with the three-dimensional structure of odorant plumes accounts for the differential effects of turbulence on the speed and success of crab tracking behavior. Separate examinations of tracking behavior and plume properties cannot directly examine hypotheses concerning the utility of specific chemical signal properties. In order to make a direct link between cue and behavior, three-dimensional laser induced fluorescence (3DLIF) was used to analyze three-dimensional plume structure and concentration of odor filaments that reach blue crab sensory structures. The corresponding tracking behavior was simultaneously recorded and then analyzed with a motion analysis system. These data provide the most comprehensive examination of odor signal input-behavioral output functions for animals in turbulent plumes. Crabs do not react differentially in response to the absolute concentration of antennule spikes above threshold at their antennules but do show a state-dependent acceleration response to antennule spikes. Signals arriving at the leg sensors of blue crabs help mediate upstream motion and signal change across a single set of leg sensors is sufficient to induce turning during upstream motion. Blue crabs decrease the height of their antennules in correspondence with changing plume properties as they approach the source and the timing of signals arriving at the antennules appears to affect upstream motion.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第20156号 / 理博第4241号 / 新制||理||1610(附属図書館) / 京都大学大学院理学研究科数学・数理解析専攻 / (主査)教授 國府 寛司, 教授 上田 哲生, 教授 堤 誉志雄 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

Neste trabalho estudaremos a existência de soluções fracas para uma classe de equações diferenciais funcionais impulsivas com retardamento dependendo do estado modeladas na forma \'x POT. PRIME\'(t) = Ax(t) + f(t;\' x IND. p(t, xt)), t \'PERTENCE A\'I = [0,a], \'x IND. 0\' =\\varphi \'PERTENCE A\' B, \'DELTA\' \'x(t IND. i) = \'I IND.i\'i(\'x IND.i\'); i = 1, ...n, onde A é o gerador infinitesimal de um \'C IND. 0\'-semigrupo compacto de operadores lineares limitados (\'T\'(t))t \'. OU =\'0 definido em um espaço de Banach X; as fun»ções \'x IND. s\' : (- \'INFIINITO\', 0] \'SETA\' X, \'x IND. s\' ( teta\') = x(s + \'teta\'), estão em um espaço de fase B descrito axiomaticamente; f : I X B \'seta\' X, \'rô\' : I X B \'SETA\' ( - \'INFINITO\', a], \'I IND. i\' : B \'SETA\'X, i=1, ...n , são funções apropriadas; 0 < \'t IND.1\' <... < \'t IND. n\' < a são n¶umeros pré-fixados e o símbolo \'DELTA\'\'ksi\'(t) = \'Ksi\'(\'t POT. + ) - \'ksi\'( \'t POT. -). / In this work we stablish the existence of mild solutions for an impulsive abstract functional differential equation with state-dependent delay described in the form \'x POT. PRIME\'(t) = Ax(t) + f(t;\' x IND. p(t, xt)), t \'BELONGS\'I = [0,a], \'x IND. 0\' =\\varphi \'IS CONTAINED\' B, \'DELTA\' \'x(t IND. i) = \'I IND.i\'i(\'x IND.i\'); i = 1, ...n, where A is the infinitesimal generator of a compact \'C IND. 0\'-semigroup of bounded linear operators (\'T\'(t))t \'. OU =\'0 defined on a Banach space X; the functions \'x IND. s\': ( - INFINito, 0] \'SETA X, \'x IND. s\'(\'teta\') , belongs to some space B described axiomatically; f : I X B \'seta\' X, \'rô\' : I X B \'SETA\' ( - \'INFINITO\', a], \'I IND. i\' : B \'SETA\'X, i=1, ...n , são funções apropriadas; 0 < \'t IND.1\' <... < \'t IND. n\' < a são n¶umeros pré-fixados e o símbolo \'DELTA\'\'ksi\'(t) = \'Ksi\'(\'t POT. + ) - \'ksi\'( \'t POT. -).

This thesis deals with development of guidance laws for advanced applications. Two class of guidance problems, namely, impact angle constrained guidance and pulsed guidance for exo-atmospheric engagements, are considered here. Three impact angle constrained guidance schemes are developed using (i) Proportional navigation guidance (PNG), (ii) State Dependent Riccati Equation (SDRE) technique and (iii) geometric concepts, respectively. A collision course based pulsed guidance law is presented for exo-atmospheric interceptors. Proportional Navigation Guidance (PNG) law is the most widely used guidance law because of its ease of implementation and efficiency. However, in its original form, it achieves only a limited set of impact angles. A two stage PNG law is presented for achieving all impact angles against a stationary target. In the first phase of guidance, an orientation PNG command is used. The orientation navigation constant (N ) is a function of the initial engagement geometry and has a lower value (N less than 2). It is proved that following the orientation trajectory, the interceptor can switch to N = 2 and achieve the desired impact angle. Simulations, with a constant speed and with a realistic interceptor model, show successful interception of the target with all desired impact angles. Feedback implementation of the guidance law results in negligible errors in impact angle with uncompensated autopilot delays. The idea of a two-stage PNG law with impact angle constraint is further used to develop a guidance law for intercepting moving targets. Following the orientation trajectory, the interceptor can switch to N = 3 and achieve the desired impact angle. It is proved that the guidance achieves all impact angles in a surface-to-surface engagement scenario with receding and approaching targets, respectively. In a air-to-surface engagement scenario, it is proved that the guidance law achieves all impact angles in a deterministic set. Constant speed and realistic interceptor models are used for simulations. Results show negligible error in impact angle and miss distance for moving targets. The guidance law, in its feedback implementation form, achieves the desired impact angle for interceptors with delay and with a maneuvering target. The impact angle errors are low with negligible errors in miss distance. Next, the impact angle constrained guidance problem against a stationary target is solved as a non-linear regulator problem using the SDRE technique. The interceptor guidance problems are of finite time nature. As the main contribution of this part of the work, we solve a finite time interceptor guidance problem with infinite horizon SDRE formulation by choosing the state weighting matrix as a function of time-to-go. Numerical simulations are carried out both for a constant speed interceptor model and a realistic interceptor model. Simulations for both the models are carried out for various impact angles and firing angles. Robustness of the proposed guidance law with respect to autopilot lag is also verified by simulations. Results obtained show the efficiency of the SDRE approach for impact angle constrained missile guidance. A geometric guidance scheme is proposed for lateral interception of targets in a planar engagement scenario in the absence of line-of-sight rate information. A kill-band is defined for target initial positions capturable by an arc maneuver, followed by a straight line path by the interceptor. Guidance law for capturing targets inside the kill-band is presented and is further modified for targets outside the kill-band. Based on analytical studies on the kill-band, a guidance law is proposed for lateral interception of maneuvering targets. Simulations are carried with for typical low speed engagements. The concept of kill-band provides an inherent robustness to the proposed guidance law with respect to uncompensated system delays and target maneuver. As the final part of the work, an interceptor endgame pulsed guidance law for exoatmospheric engagements is derived by using the notion of collision heading. The proposed guidance law is derived in steps by (i) Obtaining the collision heading based on the collision triangle engagement geometry and then (ii) Computing the width of the pulse fired by the divert thruster to attain the collision heading. It is shown that this strategy is more effective than the existing zero effort miss (ZEM) based guidance laws for intercepting targets with higher heading angles off the nominal head-on collision course. A result on pulse firing sequence is also presented showing that firing pulses in quick succession results in minimum pulse widths and hence minimum control effort for a desired miss distance. Simulations are carried out for various engagement scenarios. Results show better miss-distance and divert thrust performance as compared to the existing ZEM based law.

Cette thèse est consacrée à l'étude d'une classe d'équations différentielles à retard dépendant de l'état -- ces équations provenant d'un modèle structuré en taille. La principale motivation de cette thèse provient de la volonté d'ajuster les paramètres du système d'équations étudiées vis-à-vis des données générées par un simulateur de forêts, appelé SORTIE. Deux types de forêts sont étudiés ici: d'une part une forêt ne comportant qu'une seule espèce d'arbre, et d'autre part une forêt comportant deux espèces d'arbres (au chapitre 2). Les simulations numériques du système d'équations correspondent relativement bien aux données générées par SORTIE, ce qui montre que le système considéré peut être utilisé afin d'écrire la dynamique de populations d'une forêt. De plus, un modèle plus étendu prenant en compte la position spatiale des arbres est proposé dans le chapitre 2, dans le cas de forêts possédant deux espèces d'arbres. Les simulations numériques de ce modèle permettent de visualiser la propagation spatiale des forêts. Les chapitres 3 et 4 se concentrent sur l'analyse mathématique des équations différentielles à retard considérées. Les propriétés du semi-flot associé au système sont étudiées au chapitre 3, où l'on démontre en particulier que ce semi-flot n'est pas continu en temps. Le caractère dissipatif et borné du semi-flot, pour des modèles de forêts comportant une ou deux espèces d'arbres, est étudié dans le chapitre 4. En outre, afin d'étudier la dynamique de population d'une forêt (d'une seule espèce d'arbre) après l'introduction d'un parasite, nous construisons dans le chapitre 5 un système proie-prédateur dont la proie (à savoir la forêt) est modélisée par le système d'équations différentielles à retard dépendant de l'état étudié auparavant, et dont le prédateur (à savoir le parasite) est modélisé par une équation différentielle ordinaire. De nombreuses simulations numériques associées à différents scénarios sont faites, afin d'explorer le comportement complexe des solutions du au couplage proie-prédateur et les équations à retard dépendant de l'état. / This thesis is devoted to the studies of a class of state-dependent delay differential equations. This class of equations is derived from a size-structured model.The motivation comes from the parameter fittings of this system to a forest simulator called SORTIE. Cases of both single species forest and two-species forest are considered in Chapter 2. The numerical simulations of the system correspond relatively very well to the forest data generated by SORTIE, which shows that this system is able to be used to describe the population dynamics of forests. Moreover, an extended model considering the spatial positions of trees is also proposed in Chapter 2 for the two-species forest case. From the numerical simulations of this spatial model one can see the diffusion of forests in space. Chapter 3 and 4 focus on the mathematical analysis of the state-dependent delay differential equations. The properties of semiflow generated by this system are studied in Chapter 3, where we find that this semiflow is not time-continuous. The boundedness and dissipativity of the semiflow for both single species model and multi-species model are studied in Chapter 4. Furthermore, in order to study the population dynamics after the introduction of parasites into a forest, a predator-prey system consisting of the above state-dependent delay differential equation (describing the forest) and an ordinary differential equation (describing the parasites) is constructed in Chapter 5 (only the single species forest is considered here). Numerical simulations in several scenarios and cases are operated to display the complex behaviours of solutions appearing in this system with the predator-prey relation and the state-dependent delay.

Submitted by Daniella Santos (daniella.santos@fgv.br) on 2010-03-11T13:25:30Z No. of bitstreams: 1 Tese_Fabio_Araujo_Final.pdf: 715897 bytes, checksum: 17afb0d85c3fff397df747b1a0d56bf9 (MD5) / Approved for entry into archive by Andrea Virginio Machado(andrea.machado@fgv.br) on 2010-03-12T13:27:41Z (GMT) No. of bitstreams: 1 Tese_Fabio_Araujo_Final.pdf: 715897 bytes, checksum: 17afb0d85c3fff397df747b1a0d56bf9 (MD5) / Made available in DSpace on 2010-03-15T12:06:11Z (GMT). No. of bitstreams: 1 Tese_Fabio_Araujo_Final.pdf: 715897 bytes, checksum: 17afb0d85c3fff397df747b1a0d56bf9 (MD5) Previous issue date: 2009-08-10 / This work proposes alternative ways to consistently estimate an abstract measure, crucial to the study of intertemporal decisions, which is at the core of most macroeconomics and financial studies: the Stochastic Discount Factor (SDF). Using the Pricing Equation in a panel-data framework, is constructed a novel consistent estimator of the SDF which relies on the fact that its logarithm is pervasive to all asset returns of the economy. The resulting estimator is very simple to compute, does not dependent on strong economic assumptions, is suitable for testing different preference specifications or investigating intertemporal substitution puzzles, and can be used as basis to construct an estimator for the risk-free rate. Alternative identification strategies are applied and a parallel between it and identifications strategies based on other frameworks is drawn. Adding structure to the initial setup, two environments were the asymptotic distribution can be derived are presented. Finally, methodologies proposed are applied US and Brazilian data. Preference specifications usually found in the macro literature, as well as a class of state dependent preferences, are tested. The results for the US economy are particularly interesting, by performing formal tests, we cannot reject standard preference specifications used in the literature and estimates of the relative risk-aversion coefficient are between 1 and 2, and statistically indistinguishable from the unity. Moreover, for the class of state dependent preferences and using US quarterly data from 1972:1 and 2001:4, we estimate a highly dynamic path for the relative risk-aversion (rra) coefficient, confined to the interval [1.15, 2.05], and also reject the hypothesis of a constant level. / Este trabalho propõe maneiras alternativas para a estimação consistente de uma medida abstrata, crucial para o estudo de decisões intertemporais, o qual é central a grande parte dos estudos em macroeconomia e finanças: o Fator Estocástico de Descontos (SDF, sigla em Inglês). Pelo emprego da Equação de Apreçamento constrói-se um inédito estimador consistente do SDF que depende do fato de que seu logaritmo é comum a todos os ativos de uma economia. O estimador resultante é muito simples de se calcular, não depende de fortes hipóteses econômicas, é adequado ao teste de diversas especificações de preferência e para a investigação de paradoxos de substituição intertemporal, e pode ser usado como base para a construção de um estimador para a taxa livre de risco. Alternativas para a estratégia de identificação são aplicadas e um paralelo entre elas e estratégias de outras metodologias é traçado. Adicionando estrutura ao ambiente inicial, são apresentadas duas situações onde a distribuição assintótica pode ser derivada. Finalmente, as metodologias propostas são aplicadas a conjuntos de dados dos EUA e do Brasil. Especificações de preferência usualmente empregadas na literatura, bem como uma classe de preferências dependentes do estado, são testadas. Os resultados são particularmente interessantes para a economia americana. A aplicação de teste formais não rejeita especificações de preferências comuns na literatura e estimativas para o coeficiente relativo de aversão ao risco se encontram entre 1 e 2, e são estatisticamente indistinguíveis de 1. Adicionalmente, para a classe de preferência s dependentes do estado, trajetórias altamente dinâmicas são estimadas para a tal coeficiente, as trajetórias são confinadas ao intervalo [1,15, 2,05] e se rejeita a hipótese de uma trajetória constante.

Made available in DSpace on 2016-06-02T20:06:06Z (GMT). No. of bitstreams: 1 4329.pdf: 1652803 bytes, checksum: aad7f31afeb38bcd450c35fd9ed227be (MD5) Previous issue date: 2008-09-02 / Universidade Federal de Sao Carlos / The transactions volume increase brought the fraud increase, which result in a annual loss of billions of reais to all .nancial institutions in the world. Therefore, it.s very important the development of detection methods and fraud prevention. The di¢ cult in modeling this kind of data due the fact the data sets are extremely unbalanced. In this work, a bounded logit model will be proposed for fraud detection. It will also be discussed state- dependent sampling and compared with logit and bounded logit model performances. Two applications, one with a simulated data set and another with a real data set, will be presented. The Bayesian approach to these models will also be discussed. The data set analyses will be implemented in SAS and Winbugs software. / O aumento no volume de transações com cartões de crédito trouxe como consequência o aumento do número de fraudes, o que acarreta em uma perda de bilhões de reais anu- almente à todas instituições .nanceiras do mundo. Com isso é muito importante que metodologias de detecção e prevenção à fraude sejam desenvolvidas. A grande di.cul- dade na modelagem deste tipo de dados é que estes são extremamentes desbalanceados. Neste presente trabalho, será proposto o modelo logito limitado na detecção de fraude. Também será discutido as amostras do tipo state-dependent e comparado os desempenhos dos modelos logito e logito limitado. Duas aplicações, uma com um conjunto de dados simulados e outra com um conjunto de dados reais, serão apresentadas. A abordagem bayesiana para estes modelos também será discutida. As análises dos conjuntos de dados serão realizadas nos softwares SAS e Winbugs.

Orientador: Prof. Dr. André Fenili / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Engenharia Mecânica, Santo André, 2018.

Neste trabalho estudaremos a existência de soluções fracas para uma classe de equações diferenciais funcionais impulsivas com retardamento dependendo do estado modeladas na forma \'x POT. PRIME\'(t) = Ax(t) + f(t;\' x IND. p(t, xt)), t \'PERTENCE A\'I = [0,a], \'x IND. 0\' =\\varphi \'PERTENCE A\' B, \'DELTA\' \'x(t IND. i) = \'I IND.i\'i(\'x IND.i\'); i = 1, ...n, onde A é o gerador infinitesimal de um \'C IND. 0\'-semigrupo compacto de operadores lineares limitados (\'T\'(t))t \'. OU =\'0 definido em um espaço de Banach X; as fun»ções \'x IND. s\' : (- \'INFIINITO\', 0] \'SETA\' X, \'x IND. s\' ( teta\') = x(s + \'teta\'), estão em um espaço de fase B descrito axiomaticamente; f : I X B \'seta\' X, \'rô\' : I X B \'SETA\' ( - \'INFINITO\', a], \'I IND. i\' : B \'SETA\'X, i=1, ...n , são funções apropriadas; 0 < \'t IND.1\' <... < \'t IND. n\' < a são n¶umeros pré-fixados e o símbolo \'DELTA\'\'ksi\'(t) = \'Ksi\'(\'t POT. + ) - \'ksi\'( \'t POT. -). / In this work we stablish the existence of mild solutions for an impulsive abstract functional differential equation with state-dependent delay described in the form \'x POT. PRIME\'(t) = Ax(t) + f(t;\' x IND. p(t, xt)), t \'BELONGS\'I = [0,a], \'x IND. 0\' =\\varphi \'IS CONTAINED\' B, \'DELTA\' \'x(t IND. i) = \'I IND.i\'i(\'x IND.i\'); i = 1, ...n, where A is the infinitesimal generator of a compact \'C IND. 0\'-semigroup of bounded linear operators (\'T\'(t))t \'. OU =\'0 defined on a Banach space X; the functions \'x IND. s\': ( - INFINito, 0] \'SETA X, \'x IND. s\'(\'teta\') , belongs to some space B described axiomatically; f : I X B \'seta\' X, \'rô\' : I X B \'SETA\' ( - \'INFINITO\', a], \'I IND. i\' : B \'SETA\'X, i=1, ...n , são funções apropriadas; 0 < \'t IND.1\' <... < \'t IND. n\' < a são n¶umeros pré-fixados e o símbolo \'DELTA\'\'ksi\'(t) = \'Ksi\'(\'t POT. + ) - \'ksi\'( \'t POT. -).

Cette thèse rassemble trois essais sur la théorie axiomatique de la décision.Ils relèvent principalement de l’analyse épistémologique de cette théorie.Le premier essai, “Les limites de l’ordinalisme”, concerne la doctrine ordinaliste,qui a joué un rôle important dans la constitution de la théoriemicro-économique contemporaine. Dans un premier temps, nous définissonsabstraitement cette doctrine. Nous la caractérisons par la thèse suivant laquelledes données de choix ne peuvent pas rendre empiriquement signifiantesles propriétés non-ordinales de l’utilité. Dans un second temps, nous évaluonscette thèse, la confrontant à divers développements de la théorie de la décision,qui paraissent la remettre en cause. Nous montrons que, malgré lesapparences, cette thèse n’est pas remise en cause par les développementsthéoriques que nous étudions.Le deuxième essai, “L’analyse axiomatique et l’attitude par rapport aurisque”, porte sur le statut, en théorie de la décision, des concepts d’attitudepar rapport au risque. A première vue, l’analyse axiomatique n’exploite pasces idées-là. Ceci reflète une certaine neutralité des modèles de décision ausujet de l’attitude par rapport au risque. Mais un examen plus poussé permetde mettre en valeur ce que nous nommons la variation conditionnelle et lerenforcement de l’attitude par rapport au risque, établissant par là mêmel’importance axiomatique des concepts d’attitude par rapport au risque.Le troisième essai, “Les paris révèlent-ils les croyances ?”, examine la méthodeconsistant à identifier les croyances d’un agent à partir de ses préférences.Nous nous concentrons sur l’obstacle principal auquel cette méthodeest exposée, à savoir, le problème de l’utilité dépendante des états. En premierlieu, nous illustrons ce problème de manière détaillée, distinguant quatreformes de dépendance de l’utilité aux états. En second lieu, nous présentonset discutons une stratégie permettant, malgré la possibilité d’une telle dépendance,d’identifier les croyances. Cependant, pour résoudre ainsi le problème,il faut laisser la préférence s’étendre au-delà du choix. Nous défendons quetel doit être le cas dans toute solution complète au problème de l’utilitédépendante des états. Nous affirmons aussi que c’est là la principale leçonconceptuelle à tirer de ce problème, et montrons qu’elle intéresse tant leséconomistes que les philosophes. / This thesis consists of three essays on axiomatic decision theory. Theybelong primarily to the epistemological analysis of decision theory.The first essay, “The limits of ordinalism”, focuses on ordinalism, a doctrinethat was instrumental in the constitution of contemporary microeconomictheory. First, I provide an abstract definition of this doctrine.I characterize it by the following claim: if the underlying data are choicedata, then no non-ordinal property of utility can be empirically meaningful.Second, I evaluate the above claim. I confront this claim with variousdecision-theoretic developments which seem to question its validity. I showthat, despite appearances, this claim is not challenged by the theoreticaldevelopments in question.The second essay, “Axiomatic analysis and risk attitudes”, examines thestatus of risk attitude concepts in decision theory. At first sight, axiomaticanalysis does not rely on these concepts. This indicates a certain neutrality ofdecision models regarding risk attitudes. Further analysis, however, leads oneto recognize the importance of what I call the conditional variation and thestrengthening of risk attitudes. This establishes the axiomatic significance ofrisk attitude concepts.The third essay, “Do bets reveal beliefs?”, examines the preference-basedapproach to the identification of beliefs. It focuses on the main problem towhich this approach is exposed, namely state-dependent utility. First, theproblem is illustrated in full detail. Four types of state-dependent utility issuesare distinguished. Second, a strategy for identifying beliefs under statedependentutility is presented and discussed. For the problem to be solvedfollowing this strategy, however, preferences need to extend beyond choices. Iargue that this is a necessary feature of any complete solution to the problemof state-dependent utility. I also claim that this is the main conceptuallesson to draw from this problem. I explain why this lesson is of interest toeconomists and philosophers alike.