Spelling suggestions: "subject:"anyone"" "subject:"anybone""
1 |
A within-subject comparison of stimulus equivalence training.Rawls, Medea 08 1900 (has links)
Training structures have been defined as the order and arrangement of baseline conditional discriminations within stimulus equivalence training. The three training structures most often used are, linear (trains A:B and B:C discrimination), many-to-one (trains B:A and C:A discriminations) , and one-to-many (trains A:B and A:C discriminations). Each training structure trains a different set of simultaneous and successive discriminations that are then needed in the test for derived relations (symmetry, reflexivity, transitivity, and symmetrical transitivity). The present experiment seeks to extend the research on stimulus equivalence training structures by using a within-subject design and adult human subjects. Three sets of 9 arbitrary stimuli were trained concurrently each with a different training structure. From the beginning, training and testing trials were intermixed. The likelihood of producing stimulus equivalence formation was equal across structures.
|
2 |
Conception d'un système de transmission ultra-large bande par impulsions orthogonales / Design of the ultra-wideband transceiver based on pulse orthogonalTabaa, Mohamed 21 November 2014 (has links)
Dans cette thèse, nous proposons une méthodologie de conception d’architectures de communication dédiées aux réseaux de capteurs basées sur la technique de radio impulsionnelle pour les transmissions ultralarge bande (ULB). La technique impulsionnelle proposée ici repose sur la modulation de forme d’impulsion. L’approche de conception architecturale présentée dans cette thèse se focalise plus particulièrement sur la forme des impulsions et leur génération, qui revêt un intérêt majeur puisqu’elle constitue le support de l’information échangée. L’étude sur le choix de la forme d’impulsion nous a conduit à proposer deux architectures différentes. Une première architecture repose sur les polynômes orthogonaux, et plus particulièrement sur les polynômes d’Hermite, pour la génération des impulsions, et sur une architecture de corrélation pour la détection et la reconnaissance des trains d’impulsions transmis. La deuxième architecture est basée sur la transformée en paquets d’ondelettes discrète et peut être exploitée selon deux modes d’utilisation différents, mono et multiutilisateurs. L’utilisation d’une architecture de synthèse à l’émission et d’analyse à la réception ouvre une nouvelle orientation pour les communications numériques, permettant à la transformée en ondelettes d’assurer à la fois la génération des impulsions à l’émission et leur reconnaissance à la réception. Un intérêt immédiat de la technique proposée permet notamment de faciliter l’accès multiutilisateurs au canal ultralarge bande, et d’autoriser des communications simultanées (Many-to-one, des nœuds vers le puits) ou du broadcast (One-to-many, du puits vers les nœuds) sans surcharger la couche MAC. L’architecture proposée s’inscrit donc à l’interface des couches PHY et MAC et permet de relâcher les contraintes de conception spécifiques à ces couches / In this thesis, we propose a design methodology for communication architectures dedicated to wireless sensor network based on impulse radio techniques for UWB communications. The impulse technique proposed in this work relies on pulse shape modulation. The architecture design approach proposed in this thesis focuses on pulses shape and their generation, which is of major interest as it constitutes the carrier of the information exchanged. The study on the choice of pulse shape led us to propose two different architectures. The first one is based on orthogonal polynomials, more especially on the Hermite polynomials, for impulse generation, and on a correlation architecture for detection and recognition of transmitted impulses. The second architecture is based on discrete wavelet packet transform and can be used according two different modes, mono and multi-users. The use of both synthesis and analysis architectures for emitter and receiver, respectively, offers a new way for digital communications and allows the wavelet transform to ensure the impulses generation on the transmitter and their recognition on the receiver. A major interest point of the proposed technique is to facilitate the multi-users access to the ultra-wideband channel and to allow simultaneous communications (many-to-one, from the sensors to the sink) or broadcast (one-to-many, from the coordinator to the nodes) but without overloading the MAC layer. Hence, the proposed architecture is part of the interface between both PHY and MAC layers, and allows to release their specific design constraints
|
3 |
Conception d'un système de communication sans fil industriel basé sur la transformée en ondelettes / Industrial wireless communication system based on the wavelet transformSaadaoui, Safa 29 March 2019 (has links)
Dans cette thèse, nous présenterons une architecture de communication multi-utilisateurs à base des réseaux de capteurs sans fil dans un environnement industriel fortement bruité. Deux modes de fonctionnement de cette architecture sont présentés ; un mode Many-To-One reliant plusieurs capteurs émetteurs à un seul récepteur et un mode One-To-Many reliant un émetteur à plusieurs capteurs récepteurs. La couche physique de ce système est basée sur une modulation par transformée par paquets d'ondelettes inverse (IDWPT) à l'émission et une transformée par paquets d'ondelette discrète (DWPT) en réception. Pour tester notre architecture, un modèle de canal industriel est proposé qui tient compte des phénomènes des multi-trajets et des évanouissements en plus du bruit additif. Ce dernier étant modélisé comme un bruit gaussien auquel s'additionne un bruit impulsionnel causant une dégradation significative des signaux. L'architecture est testée pour différentes configurations de communications sans fil et pour différentes formes d'ondelettes afin de proposer un mode de communication optimal. Aussi, une amélioration de la robustesse de notre système est effectuée en ajoutant un codage correcteur d'erreur du canal et un seuillage du bruit impulsionnel à la réception pour minimiser les effets du bruit industriel sur les signaux reçus. En utilisant un code correcteur d'erreur, la détection et reconstitution des signaux se fait sans erreur à partir d'un SNR de 8dB pour un taux de codage 1/4 pour une transmission sur à canal à évanouissement. Pour un récepteur optimal à base du seuillage du bruit, les performances en termes de taux d'erreur binaires sont améliorées de 10dB pour une transmission sur un canal à bruit industriel. Enfin, une comparaison de la robustesse de notre architecture impulsionnelle avec un système à base d'une modulation multi-porteuse classique OFDM est effectuée. Ceci nous amène à proposer un système de communication multi-utilisateurs robuste à base des réseaux de capteurs sans fil pour des communications en milieu industriel difficile. / In this thesis, we will present a multi-user communication architecture based on wireless sensor networks in a noisy industrial environment. Two modes of operation of this architecture are presented ; a Many-To-One mode linking several transmitter sensors to a single receiver and a One-To-Many mode linking a transmitter to several receiver sensors. The physical layer of this system is based on the inverse transform (IDWPT) at transmission and the discrete wavelet packet transform (DWPT) at reception. To test our architecture, an industrial channel model is proposed that takes into account the phenomena of multipath and fading in addition to additive noise. The latter being modelled as Gaussian noise to which is added an impulse noise causing significant signal degradation. The architecture is tested for different wireless communication configurations and wavelet shapes to provide an optimal communication mode. Also, an improvement in the robustness of our system is achieved by adding channel error correction coding and pulse noise thresholding at reception to minimize the effects of industrial noise on the received signals. Using an error-correcting code, the detection and reconstruction of signals is error-free from an SNR of 8dB for a coding rate of 1/4 for transmission on a fading channel. For an optimal receiver based on noise thresholding, the performance in terms of binary error rates is improved by 10dB for transmission over an industrial noise channel. Finally, a comparison of the robustness of our pulse architecture with a system based on a conventional OFDM multi-carrier modulation is carried out. This leads us to propose a robust multi-user communication system based on wireless sensor networks for communications in difficult industrial environments.
|
4 |
Implementation and Evaluation of a TDMA Based Protocol for Wireless Sensor NetworksFiske, Robert M. January 2010 (has links)
No description available.
|
5 |
Answer set programming probabilístico / Probabilistic Answer Set ProgrammingMorais, Eduardo Menezes de 10 December 2012 (has links)
Este trabalho introduz uma técnica chamada Answer Set Programming Probabilístico (PASP), que permite a modelagem de teorias complexas e a verificação de sua consistência em relação a um conjunto de dados estatísticos. Propomos métodos de resolução baseados em uma redução para o problema da satisfazibilidade probabilística (PSAT) e um método de redução de Turing ao ASP. / This dissertation introduces a technique called Probabilistic Answer Set Programming (PASP), that allows modeling complex theories and check its consistence with respect to a set of statistical data. We propose a method of resolution based in the reduction to the probabilistic satisfiability problem (PSAT) and a Turing reduction method to ASP.
|
6 |
Belief Propagation and Algorithms for Mean-Field Combinatorial OptimisationsKhandwawala, Mustafa January 2014 (has links) (PDF)
We study combinatorial optimization problems on graphs in the mean-field model, which assigns independent and identically distributed random weights to the edges of the graph. Specifically, we focus on two generalizations of minimum weight matching on graphs. The first problem of minimum cost edge cover finds application in a computational linguistics problem of semantic projection. The second problem of minimum cost many-to-one matching appears as an intermediate optimization step in the restriction scaffold problem applied to shotgun sequencing of DNA.
For the minimum cost edge cover on a complete graph on n vertices, where the edge weights are independent exponentially distributed random variables, we show that the expectation of the minimum cost converges to a constant as n →∞ For the minimum cost many-to-one matching on an n x m complete bipartite graph, scaling m as [ n/α ] for some fixed α > 1, we find the limit of the expected minimum cost as a function of α. For both problems, we show that a belief propagation algorithm converges asymptotically to the optimal solution. The belief propagation algorithm yields a near optimal solution with lesser complexity than the known best algorithms designed for optimality in worst-case settings.
Our proofs use the machinery of the objective method and local weak convergence, which are ideas developed by Aldous for proving the ζ(2) limit for the minimum cost bipartite matching. We use belief propagation as a constructive proof technique to supplement the objective method.
Recursive distributional equations(RDEs) arise naturally in the objective method approach. In a class of RDEs that arise as extensions of the minimum weight matching and travelling salesman problems, we prove existence and uniqueness of a fixed point distribution, and characterize its domain of attraction.
|
7 |
Answer set programming probabilístico / Probabilistic Answer Set ProgrammingEduardo Menezes de Morais 10 December 2012 (has links)
Este trabalho introduz uma técnica chamada Answer Set Programming Probabilístico (PASP), que permite a modelagem de teorias complexas e a verificação de sua consistência em relação a um conjunto de dados estatísticos. Propomos métodos de resolução baseados em uma redução para o problema da satisfazibilidade probabilística (PSAT) e um método de redução de Turing ao ASP. / This dissertation introduces a technique called Probabilistic Answer Set Programming (PASP), that allows modeling complex theories and check its consistence with respect to a set of statistical data. We propose a method of resolution based in the reduction to the probabilistic satisfiability problem (PSAT) and a Turing reduction method to ASP.
|
8 |
Three essays in microeconomic theorySidibé, Abdoul Karim 06 1900 (has links)
Cette thèse est un recueil de trois articles sur la théorie microéconomique. Les deux premiers traitent de la question de la course vers le bas lorsque les gouvernements se livrent à la concurrence pour certains facteurs mobiles. Le troisième article propose une extension du problème d'appariement plusieurs-à-un en y introduisant des agents de tailles différentes.
Dans le premier article, nous montrons comment le résultat standard de course vers le bas (race-to-the-bottom) peut être évité en introduisant du bien public dans un modèle de compétition fiscale. Notre économie comporte deux juridictions peuplées par de la main-d’œuvre parfaitement mobile répartie en deux catégories : qualifiée et non-qualifiée. Les gouvernements, en poursuivant un objectif Rawlsien (max-min), annoncent simultanément leur projet d'investissement en bien public avant d'adopter une politique de taxation non-linéaire du revenu. Les travailleurs, après avoir observé la politique de taxation des différents gouvernements et leurs promesses d'investissement en bien publique, choisissent chacun un lieu de résidence et une offre de travail. Ainsi, les gouvernements atteignent leurs objectifs de redistribution en cherchant à attirer de la main-d’œuvre productive à travers la fourniture de bien public en plus d'une politique de taxation favorable. Nous montrons qu'il existe des équilibres où les travailleurs qualifiés paient une taxe strictement positive. En outre, lorsque l'information sur le type des travailleurs est privée, il existe, pour certaines valeurs des paramètres, des équilibres où la main-d’œuvre non-qualifiée bénéficie d'un transfert net (ou subvention) de la part du gouvernement.
Dans le second article, nous étudions comment le modèle standard de compétition des prix à la Bertrand avec des produits différenciés pourrait fournir des informations utiles pour les programmes de citoyenneté par investissement dans les Caraïbes. Nous montrons que lorsque les pays peuvent être classés en deux types en fonction de la taille de leur demande, l'imposition d'un prix minimum uniforme et d'un quota maximum appropriés amène les pays à un résultat efficace qui Pareto domine l'équilibre de Nash non coopératif.
Enfin, le troisième article explore une extension du problème standard d'appariement plusieurs-à-un en y incorporant des agents de tailles différentes (familles de réfugiés) d'un côté, à assigner à des foyers de capacités différentes de l'autre. La taille d'une famille de réfugiés représente le nombre de membres qui la compose. Une caractéristique spécifique à ce modèle est qu'il n'autorise pas de répartir les membres d'une même famille entre différents foyers. Il est bien connu que, dans ces conditions, bon nombre de propriétés désirables des règles d'appariement s'effondrent. Nous faisons donc l'hypothèse des priorités croissantes avec la taille pour chaque foyer, c'est-à-dire qu'une famille d'accueil préférerait toujours un plus grand nombre de réfugiés tant que la capacité de son foyer le permet. Nous montrons qu'un appariement stable par paire existe toujours sous cette hypothèse et nous proposons un mécanisme pour le trouver. Nous montrons que notre mécanisme est non-manipulable du point de vue des réfugiés : aucun groupe de réfugiés ne pourrait tirer profit d'une déclaration truquée de leurs préférences. Notre mécanisme est également optimal pour les réfugiés en ce sens qu'il n'existe aucun autre mécanisme stable par paire qui serait plus profitable à tous les réfugiés. / This thesis is a collection of three articles on microeconomic theory. The first two articles are concerned with the issue of race-to-the-bottom when governments engage in competition for some mobile factor. The third article proposes an extension for the many-to-one matching problem by introducing different-size agents.
In the first article, we show how the standard race-to-the-bottom result can be avoided by introducing public good into a tax competition model. Our economy has two jurisdictions populated by perfectly mobile workers divided into two categories: skilled and unskilled. Governments, in pursuit of a Rawlsian objective (max-min), simultaneously announce their plans for investing in public good before deploying a nonlinear income tax schedule. After observing the tax schedules of the governments and their promises to invest in public good, each worker chooses a place of residence and a supply of labour. Thus, governments achieve their redistribution objectives by seeking to attract productive labour through the provision of public goods in addition to favorable taxation policy. We show that there exist equilibria where skilled workers pay a strictly positive tax. In addition, when information on the type of workers is private, there are equilibria for certain parameter values in which unqualified workers receive a net transfer (or subsidy) from the government.
In the second article, we investigate how the Bertrand standard price competition with differentiated products could provide useful insight for Citizenship By Investment programs in the Caribbean. We show that when countries can be classified into two types according to the size of their demand, imposing appropriate uniform minimum price and maximum quota brings countries to an efficient outcome that Pareto dominates the Non-Cooperative Nash Equilibrium.
Finally. in the third article, we explore an extension of the standard many-to-one matching problem by incorporating different-size agents (refugee families) on the many side of the market, to be assigned to entities (homes) with different capacities on the other side. A specific feature of this model is that it does not allow refugee families to be split between several homes. It is well known that many of the desirable properties of matching rules are unachievable in this framework. We introduce size-monotonic priority ranking over refugee families for each home, that is, a host family (home) would always prefer a greater number of members of refugee families until its capacity constraint binds. We show that a pairwise stable matching always exists under this assumption and we propose a mechanism to find it. We show that our mechanism is strategy-proof for refugees: no refugee family could benefit from misrepresenting his preferences. Our mechanism is also refugees optimal pairwise stable in the sense that there is no other pairwise stable mechanism that would be more profitable to all
refugees.
|
9 |
Mechanisms of binding diversity in protein disorder : molecular recognition features mediating protein interaction networksHsu, Wei-Lun 25 February 2014 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Intrinsically disordered proteins are proteins characterized by lack of stable tertiary structures under physiological conditions. Evidence shows that disordered proteins are not only highly involved in protein interactions, but also have the capability to associate with more than one partner. Short disordered protein fragments, called “molecular recognition features” (MoRFs), were hypothesized to facilitate the binding diversity of highly-connected proteins termed “hubs”. MoRFs often couple folding with binding while forming interaction complexes. Two protein disorder mechanisms were proposed to facilitate multiple partner binding and enable hub proteins to bind to multiple partners: 1. One region of disorder could bind to many different partners (one-to-many binding), so the hub protein itself uses disorder for multiple partner binding; and 2. Many different regions of disorder could bind to a single partner (many-to-one binding), so the hub protein is structured but binds to many disordered partners via interaction with disorder. Thousands of MoRF-partner protein complexes were collected from Protein Data Bank in this study, including 321 one-to-many binding examples and 514 many-to-one binding examples. The conformational flexibility of MoRFs was observed at atomic resolution to help the MoRFs to adapt themselves to various binding surfaces of partners or to enable different MoRFs with non-identical sequences to associate with one specific binding pocket. Strikingly, in one-to-many binding, post-translational modification, alternative splicing and partner topology were revealed to play key roles for partner selection of these fuzzy complexes. On the other hand, three distinct binding profiles were identified in the collected many-to-one dataset: similar, intersecting and independent. For the similar binding profile, the distinct MoRFs interact with almost identical binding sites on the same partner. The MoRFs can also interact with a partially the same but partially different binding site, giving the intersecting binding profile. Finally, the MoRFs can interact with completely different binding sites, thus giving the independent binding profile. In conclusion, we suggest that protein disorder with post-translational modifications and alternative splicing are all working together to rewire the protein interaction networks.
|
Page generated in 0.0406 seconds