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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

Procedimiento de diseño estructural de un reservorio circular apoyado de concreto armado cumpliendo los parámetros de la propuesta de norma E030 2014 para la zona de Cajamarquilla

Carrión Janampa, Luis Víctor Dante, Corpus Chirinos, Byron Enmanuel January 2015 (has links)
La carencia de servicios básicos como agua potable, para zonas como Cajamarquilla, es un problema social que se debe solucionar. Ante esta situación existen proyectos para dotar de servicios de agua a la zona, que por la geografía que presentan se utilizarán reservorios apoyados en los cerros aledaños. El procedimiento de diseño de un reservorio circular de concreto para la zona, servirá como guía para futuros proyectos. Siendo el objetivo de la investigación proponer criterios y un método adecuado para diseñar la estructura de un reservorio de concreto armado que cumplan con los parámetros de la propuesta de norma E030 2014 para la zona de Cajamarquilla, dada la poca información que existe de estos a pesar de ser de uso muy común en nuestro país. El tipo de la investigación es cualitativo, correlacional y de diseño experimental puro, con el fin de obtener resultados certeros para el diseño de reservorio. Finalmente, el método a usar es el que propone la norma del ACI 350-06, basándose en masas impulsivas y convectivas, del modelo de Housner, para el análisis estático mientras que para análisis el dinámico se utilizó el software Sap2000, por el método de elementos finitos y aplicando el espectro de diseño de la norma ACI 350 adecuándose a la norma peruana, como también para el diseño estructural de los elementos del tanque. La distorsión hallada es de 0.001 y que las cortantes basales estáticas y dinámicas son similares estando en un rango de 90%, por lo que se cumplen con los parámetros de la nueva propuesta de norma E030 2014. The lack of basic services such as water, to areas like Cajamarquilla, is a social problem to be solve. In this situation there are plans to provide water services to the area, by geography reservoirs that have supported in the surrounding hills are used. The process of designing a concrete circular reservoir area will serve as a guide for future projects. As the aim of the research propose criteria and an appropriate method to design the structure of a reinforced concrete reservoir that meet the parameters of the proposed rule for the 2014 E030 Cajamarquilla area, given the little information that exists in spite of these It is very commonly used in our country. The type of research is qualitative, pure correlational and experimental design, in order to obtain accurate results reservoir design. Finally, the method used is the standard proposed by the ACI 350-06, based on impulsive and convective mass Housner model for static analysis while for the Sap2000 dynamic analysis software used by the method of and applying the finite element design spectrum ACI 350 standard adapting to the Peruvian standard, as well as for the structural design of the elements of the tank. The distortion founded that the cutting 0.001y static and dynamic baseline are like being in a range of 90%, so that meet the parameters of the new E030 2014 proposed rule.
152

AVALIAÇÃO ACÚSTICA DE UM TEMPLO CATÓLICO DE GRANDES DIMENSÕES SUBMETIDO À EXCITAÇÃO IMPULSIVA / ACUSTIC ASSESSMENT OF A LARGE DIMENSIONED CATHOLIC TEMPLE SUBMITTED TO IMPULSIVE EXCITATION

Barbo, Marselle Nunes 02 March 2009 (has links)
The proposal to evaluate churches acoustically brings two relevants aspects: the importance of sound quality in religious environments and its consequence to the followers. The present work analyzes the acoustic performance of a Basilic with contemporary architecture, evaluating data obtained from experiments performed in loco from the impulsive reply due to excitement for source of manual and semistructured interviews with followers and enthusiasts. The premises studied are the Basilic Sanctuary of Our Lady Medianeira that consists of an important center dedicated to the Patroness of Rio Grande do Sul State. In a church, good speech intelligibility is necessary for the right comprehension from the audience. Music also should be clearly understood. A wooden device manufactured by UFSM s Acoustic Sector regarding scientific researches, revealed ability of impulsive signal emission necessary for carrying out the measurements. After the source validation, the environment acoustic assessment was determined according quality and intelligibility rates for music and speech. Then it was obtained values of Reverberation Time (RT), Initial Decay Time (IDT), Clarity (C80) and Definition (D50). The data, collected with an equipment called Blue Solo from 01-dB, had its analysis effectively checked by computational program dBBati. Interviews with followers and Mass leaders such as priests, musicians and commentators indicated that people perceive sound irregularities in the premisses, however can not identify where are the aggravators of this particular situation. This analysis meets the answers of objective parameters, where is noticed that the premisses show lacking of sound quality, making it rather difficult the understanding of either the speech or the music. / A proposta de avaliar acusticamente igrejas traz dois aspectos relevantes: a importância da qualidade sonora em ambientes religiosos e a sua conseqüência para os freqüentadores. O presente trabalho analisa o desempenho acústico de uma Basílica, com arquitetura contemporânea, avaliando dados obtidos de experimentos realizados in loco, a partir da resposta impulsiva devido à excitação por fonte de impacto manual e de entrevistas semiestruturadas com freqüentadores e celebrantes. O local estudado é o Santuário-Basílica de Nossa Senhora Medianeira, que se constitui num importante centro dedicado à Padroeira do Rio Grande do Sul. Numa igreja, uma boa inteligibilidade da palavra proferida é necessária para ser bem compreendida pelos fiéis. A música também deve ser claramente percebida. Um dispositivo de madeira produzido no Setor de Acústica da UFSM, a partir de um estudo científico, revelou-se capaz de emitir o sinal impulsivo necessário para a realização das medições. Após a validação da fonte, a avaliação acústica do ambiente foi determinada em função dos índices referentes à qualidade e à inteligibilidade para a música e para a palavra. Foram obtidos os valores do Tempo de Reverberação (TR), Tempo de Decaimento Inicial (EDT), Clareza (C80) e Definição (D50). Os dados, coletados com o equipamento Blue Solo da 01- dB, tiveram sua análise efetivada pelo programa computacional dBBati. Entrevistas com os freqüentadores e executores das missas como os padres, músicos e comentaristas indicaram que as pessoas percebem a irregularidade sonora na edificação, porém não conseguem identificar onde estão os agravantes dessa situação. Essa análise vem ao encontro das respostas dos parâmetros objetivos, onde se constatou que a edificação apresenta carência em sua qualidade sonora, dificultando na compreensão tanto da palavra falada, quanto da música.
153

Akustická detekce výstřelů ve volné přírodě / Acoustical detection of gunshots in the open

Hrabina, Martin January 2015 (has links)
This work is concerned with gunshot detection and recognition. Contains overview of published works and methods used in this field. Furthermore, it lists several commercial gunshot detectors. Binary gunshot detection and recognition algorithm is proposed which discriminates between gunshot and non-gunshot sounds occuring in nature. Algorithm is tested in Matlab. Proposed algorithm is implemented in TMS320C6713 digital signal processor, achieved results are compared.
154

Guidance and robust control methods for the approach phase between two orbital vehicles with coupling between translational and rotational motions / Méthodes de guidage-contrôle robuste pour la phase d'approche entre deux véhicules orbitaux avec couplage des mouvements de translation et de rotation

Urbina Iglesias, Laura Sofia 22 June 2017 (has links)
Les techniques liées au vol en formation et aux opérations de proximité de satellites autonomes font partie des technologies opérationnelles spatiales les plus marquantes et les plus ambitieuses de ces dernières années. En particulier, cela nécessite la complète maitrise des phases de rendez-vous proche et de survol par un satellite actif avec un satellite, une station ou un débris passif. Le développement de systèmes GNC (Guidage Navigation Contrôle) associés performants et sûrs repose sur la connaissance d'un modèle dynamique réalisant un bon compromis entre faible complexité et prise en compte suffisante des principales caractéristiques dynamiques et cinématiques de ce type de systèmes. La première partie de cette thèse est consacrée au développement d'une modélisation unifiée de la dynamique relative couplée entre un satellite coopératif chasseur et un satellite cible non coopérative. En effet, lorsque deux satellites sont proches l'un de l'autre, ils ne peuvent plus être traités comme des masses ponctuelles, car leur forme et leur taille affectent le mouvement relatif entre les points de masse décentralisés, conduisant à un couplage des mouvements de translation et de rotation. Ce développement est abordé de manière progressive: le mouvement de translation relatif non linéaire est décrit sous hypothèses képlériennes dans le repère orbital de la cible ainsi que le modèle linéarisé associé. Ensuite, le modèle non linéaire d'attitude relative est présenté au moyen des paramètres d'Euler-Rodrigues. Enfin, le formalisme des quaternions duaux est utilisé afin d'obtenir le modèle relatif couplé en translation et en attitude. La phase de modélisation du mouvement relatif linéaire de translation a ainsi permis de mettre en évidence certaines transformations de coordonnées conduisant à une caractérisation intéressante des trajectoires périodiques du chasseur et ainsi de proposer un premier type de loi de contrôle de guidage pour la phase d'approche et de survol. Dans l'ensemble de notre travail, nous considérons un chasseur équipé de propulseurs chimiques et l'hypothèse classique des poussées impulsionnelles. Ce type de systèmes dynamiques conciliant dynamique continue et contrôle impulsionnel se définit naturellement comme une classe particulière de systèmes dynamiques hybrides. Plusieurs lois de contrôle hybrides sont alors proposées afin de stabiliser le chasseur sur une trajectoire de référence périodique proche de la cible. Les propriétés de stabilité et de convergence de ces différentes lois sont analysées et de nombreuses simulations numériques montrent les forces et les faiblesses de chaque contrôleur en termes d'indices de performance comme le temps de convergence, la consommation ainsi que des contraintes de sécurité. Dans un second temps, des contraintes opérationnelles supplémentaires (contraintes de visibilité par exemple) sont prises en considération en imposant une direction d'approche rectiligne (glideslope) au chasseur. Cette trajectoire impose au satellite chasseur de suivre une droite dans n'importe quelle direction du repère local reliant l'emplacement courant du chasseur à sa destination finale. Sous l'hypothèse de propulsion impulsionnelle, les résultats existant dans la littérature pour ce type d'approche ont été généralisés aux orbites elliptiques en identifiant une nouvelle formulation du problème comprenant des degrés de liberté utiles qui permettent de minimiser la consommation de carburant tout en contrôlant l'excursion de la trajectoire libre en dehors de la droite de glideslope en la confinant dans un couloir d'approche défini par l'utilisateur. La synthèse des lois de guidage ainsi obtenues repose sur la résolution de problèmes d'optimisation SDP dans le cas général ou linéaire pour les cas plus simples d'approche standards du type V-bar ou R-bar. / The techniques related to formation flying and proximity operations of autonomous satellites belong to the most significant and challenging operational space technologies of the last years. In particular, they require full mastery of the close-range rendezvous and observation phases by an active satellite with a passive satellite, station or debris. The development of efficient and safe associated GNC systems relies on the knowledge of a dynamic model that achieves a good trade-off between low complexity and sufficient inclusion of the main dynamic and kinematic characteristics of this type of systems.The first part of this thesis is devoted to the development of a unified modeling of the relative coupled dynamics between a cooperative chaser satellite and a non-cooperative target satellite. Indeed, when two satellites are close to each other, they can no longer be treated as point masses because their shape and size affect the relative motion between the decentralized points, leading to a translational-attitude motions coupling. This development is addressed in a progressive way: the relative nonlinear translational motion is described under Keplerian assumptions in the target's orbital reference frame, as well as the associated linearized model. Then, the nonlinear relative attitude model is presented by means of the Euler-Rodrigues parameters. Finally, the dual quaternion formalism is used to obtain the relative translational and attitude coupled model. The modeling phase concerning the linear relative translational motion has allowed us to highlight certain coordinates transformations leading to an interesting characterization of the chaser's periodic trajectories and thus, to propose a first type of control law for the close-phase rendezvous and observation phases.All along this work, we consider a chaser satellite equipped with chemical thrusters under the classical hypothesis of impulsive thrusts. This type of dynamic systems gathering continuous dynamics and impulsive control naturally belongs to a particular class of dynamical hybrid systems. Several hybrid control laws are then proposed in order to stabilize the chaser on a periodic reference trajectory close to the target. The stability and convergence properties of these different laws are analysed and several numerical simulations show the strengths and weaknesses of each controller in terms of performance indices such as convergence time, consumption and safety constraints. In a second step, additional operational constraints (line-of-sight constraints for example) are taken into account by imposing a rectilinear (glideslope) direction to the chaser. This trajectory requires the chaser satellite to follow a straight line in any direction of the local reference frame and connecting the current location of the chaser to its final destination. Under the impulsive propulsion assumptions, the results in the literature for this type of approach have been generalized to elliptic orbits by identifying a new formulation of the problem including useful degrees of freedom, which allow minimizing the fuel consumption while controlling the humps of the trajectory outside the glideslope line by enclosing it in a user-defined approach corridor. Guidance laws are therefore synthetized via the solution of an SDP optimisation problem in the general case and via a linear programming when considering standard cases like the V-bar or R-bar approaches.
155

Optogenetic Inhibition of the mPFC During Delay Discounting

White, Shelby M. 05 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Impulsivity, or the tendency to act prematurely without foresight, has been linked to a diverse range of pathological conditions. Foresight refers to the ability to envision future rewards and events (i.e. prospectively sample) and has been associated with decreased impulsivity. One form of impulsivity is measured by the ability to delay gratification and is often studied in the framework of Delay Discounting (DD). DD provides the means to study impulsivity in a number of pathological conditions. However, whether impulsivity precedes the development of pathological states or results from the pathological state itself is not fully understood. This necessitates an understanding of neurobiological mechanisms contributing to decision making in both non-impulsive as well as impulsive populations of individuals. Animal models allow invasive techniques to be used to dissect the neurocircuitry involved in decision making. Given that the decision-making process is an ongoing process rather than an isolated event, optogenetics provide the temporal and spatial specificity necessary for evaluating brain region specific contributions to decision making in DD. In the present study, optogenetics were used to assess the contribution of the medial Prefrontal Cortex (mPFC), a brain region involved in ‘goal-directed’ behavior, in the planning of future choices (i.e. prospective plans) and subsequent measures of impulsivity in an adjusting amount DD procedure. Optogenetic inhibition of mPFC was conducted in Wistar rats during different epochs of a DD task in order to assess how mPFC affects planning behavior in a population of rat not considered to be highly impulsive. Although no direct effects on planning behavior (e.g. consistency) were observed, inhibiting mPFC after a trial has been initiated and directly before a choice was made (Epoch 2) was observed to increase measures of impulsivity in comparison to days where no optogenetic manipulation occurred in a delay-specific manner. This suggests that mPFC differentially contributes to decision making at different delays. A pattern of associations between choice latency, impulsivity, and consistency began to emerge for inactivation occurring in Epoch 2, suggesting that mPFC contributes to some aspect of planning choices during this epoch. Moreover, these results indicate that mPFC is involved in decision making in Wistar Rats. Understanding the direct role that mPFC plays in promoting choices of delayed rewards provides a neurobiological target for treatment aimed at reducing impulsivity in the clinical population.
156

High Speed Turbo Tcm Ofdm For Uwb And Powerline System

Wang, Yanxia 01 January 2006 (has links)
Turbo Trellis-Coded Modulation (TTCM) is an attractive scheme for higher data rate transmission, since it combines the impressive near Shannon limit error correcting ability of turbo codes with the high spectral efficiency property of TCM codes. We build a punctured parity-concatenated trellis codes in which a TCM code is used as the inner code and a simple parity-check code is used as the outer code. It can be constructed by simple repetition, interleavers, and TCM and functions as standard TTCM but with much lower complexity regarding real world implementation. An iterative bit MAP decoding algorithm is associated with the coding scheme. Orthogonal Frequency Division Multiplexing (OFDM) modulation has been a promising solution for efficiently capturing multipath energy in highly dispersive channels and delivering high data rate transmission. One of UWB proposals in IEEE P802.15 WPAN project is to use multi-band OFDM system and punctured convolutional codes for UWB channels supporting data rate up to 480Mb/s. The HomePlug Networking system using the medium of power line wiring also selects OFDM as the modulation scheme due to its inherent adaptability in the presence of frequency selective channels, its resilience to jammer signals, and its robustness to impulsive noise in power line channel. The main idea behind OFDM is to split the transmitted data sequence into N parallel sequences of symbols and transmit on different frequencies. This structure has the particularity to enable a simple equalization scheme and to resist to multipath propagation channel. However, some carriers can be strongly attenuated. It is then necessary to incorporate a powerful channel encoder, combined with frequency and time interleaving. We examine the possibility of improving the proposed OFDM system over UWB channel and HomePlug powerline channel by using our Turbo TCM with QAM constellation for higher data rate transmission. The study shows that the system can offer much higher spectral efficiency, for example, 1.2 Gbps for OFDM/UWB which is 2.5 times higher than the current standard, and 39 Mbps for OFDM/HomePlug1.0 which is 3 times higher than current standard. We show several essential requirements to achieve high rate such as frequency and time diversifications, multi-level error protection. Results have been confirmed by density evolution. The effect of impulsive noise on TTCM coded OFDM system is also evaluated. A modified iterative bit MAP decoder is provided for channels with impulsive noise with different impulsivity.
157

A Search for Ultra-high Energy Cosmic Neutrinos: Data Analysis of the Antarctic Impulsive Transient Antenna, Third Flight

Stafford, Samuel J. 07 December 2017 (has links)
No description available.
158

Beyond the Click : Unveiling the Influence of AI Personalization on E-commerce Impulse Buys

Ram, Mahabad, Maryam, Parvin, Bernard, Alexia Tatiana January 2024 (has links)
ABSTRACT Date: 2024 Level: Bachelor Thesis in Business Administration, 15 cr Institution: School of Business, Society and Engineering, Mälardalen University Authors: Tatiana Bernard, Alexia; Parvin, Maryam; Ram, Mahabad Title: Beyond the Click: Unveiling the Influence of AI Personalization on E-commerce Impulse Buys Supervisor: Emre Yildiz Keywords: AI personalized recommendations, impulsive buying behavior, perceived value, perceived scarcity, perceived positive emotions. Research question: How does AI-powered personalized product recommendations influence impulsive buying behavior in e-commerce, potentially mediated by underlying psychological mechanisms? Purpose: The purpose of this study is to examine the link between AI-powered personalized product recommendations and consumers’ impulsive buying on e-commerce platforms. The research explores how these personalized recommendations might influence customers towards impulsive purchases through perceived value, scarcity, and positive emotions as mediating factors. Method: This study utilized a quantitative research methodology, employing online surveys to collect data from active online shoppers. To ensure a comprehensive sample, both convenience and purposive sampling techniques were implemented, aiming to represent a broad spectrum of online shopping behaviors. Conclusion: This study reveals that AI-powered personalized product recommendations significantly influence impulsive buying behaviors on e-commerce platforms. By examining the mediating effects of perceived value, scarcity, and positive emotions, the research highlights how personalized recommendations can drive impulsive purchases. The findings underscore the importance of sophisticated recommendation systems in enhancing consumer engagement and satisfaction while raising important ethical considerations about consumer manipulation and long-term satisfaction. This study provides valuable insights for businesses looking to balance effective marketing strategies with ethical consumer practices.
159

Touch beyond the screen : A study on how live streaming e-commerce product displays affects consumer impulsive buying behaviour

Hou, Xinmeng, Geng, Xinyi January 2024 (has links)
In recent years, with the rapid development of Internet technology, live streaming e-commerce has gradually become the focus of public attention and has occupied an increasingly important position in consumers' daily lives. The significant difference between online retail and offline retail is whether consumers can directly touch the products, and the perception of the products plays a key role in consumers' purchasing decisions. Therefore, how to display products effectively is crucial for online retailers. This study aims to explore how the product display method of live streaming e-commerce affects consumers' impulsive buying behaviour, and collect consumers' views on live streaming e-commerce through questionnaires. The results show that improving the vividness and interactivity of product displays significantly enhances virtual touch, which in turn promotes impulsive buying behaviour. However, there is a positive correlation between virtual touch and perceived risk, and perceived risk fails to significantly inhibit impulsive buying behaviour, but instead shows a positive correlation, that is, high perceived risk increases impulsive buying behaviour. The conclusions of this study provide new insights into the future interaction model between online retailers and consumers, promote two-way communication, and improve communication efficiency. Through this study, online retailers can provide consumers with an experience closer to offline shopping when using live streaming e-commerce, thereby more effectively prompting consumers to make purchasing decisions.
160

The influence of TikTok : Understanding the Influence of TikTok UGC on Gen Z’s Impulsive Buying Behavior regarding Beauty Products.

Ringborg, Linn, Ohlsson, Ida January 2024 (has links)
As social media platforms continue to evolve, the rapid evolution has significantly transformed consumer behavior, particularly among generation Z. TikTok has emerged as a particularly dominant force and therefore this thesis investigates the influence of TikTok User-generated content on impulsive buying behavior towards beauty products among generation Z. Through a qualitative analysis the authors explore the intricate dynamics of TikToks UGC, aiming to uncover trends and patterns that trigger impulsive purchases.  Drawing on semi-structured interviews with Generation Z beauty consumers, the study investigates how TikTok's unique features and content dynamics drive impulsive purchases. The analysis focuses on identifying key trends and patterns in UGC that contribute to spontaneous buying decisions, as well as understanding the role of authenticity, trust, and emotional engagement in this process. The findings reveal that individuals who spend more time on TikTok are more likely to exhibit impulsive buying behavior. Key factors influencing these behaviors include the perceived honesty and expertise of influencers, the relatability and aspirational qualities of content creators, and the repeated exposure to products. Limited editions and perceived exclusivity further amplify the urgency to purchase. TikToks video format, which provides immediate and relatable visual proof of products effectiveness, plays a crucial role in driving these impulsive buying decisions. This study underscores the importance for brands to strategically leverage TikToks platform to engage with Generation Z consumers effectively. By creating honest, relatable content and utilizing the power of repeated exposure, brands can enhance consumer engagement and drive sales, fostering long term trust and loyalty among Generation Z consumers.

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