• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 94
  • 69
  • 17
  • 15
  • 8
  • 6
  • 3
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 277
  • 277
  • 89
  • 71
  • 51
  • 47
  • 33
  • 33
  • 30
  • 28
  • 24
  • 23
  • 22
  • 21
  • 20
  • 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.
71

Enactive Education: Dynamic Co-emergence, Complexity, Experience, and the Embodied Mind

Zorn, Diana M. 31 August 2011 (has links)
The potential of a broad enactive approach in education has yet to be realized. This thesis contributes to the development of a well-rounded enactive educational theory and practice. This thesis argues that a broad enactive perspective has the potential to challenge, reframe and reconfigure problems, issues and practices in education in ways that improve teaching, learning and research communities. It establishes that a broad enactive approach as a theory of embodied mind, a dynamic co-emergence theory, and a method of examining human experience helps to realize the meaning, scope, and potential of enactive education. It takes as its point of departure Dewey’s broad enactive philosophy of mind, cognition, embodiment, experience, and dynamic co-emergence. It shows, through an examination of an actual public classroom encounter, that a broad enactive approach has the potential to reconfigure responsibility, ethics and justice in education. It demonstrates using a case study of the enactment of impostor feelings in higher education how a broad enactive approach to education as the potential to reconfigure teaching, learning and research practices.
72

Enactive Education: Dynamic Co-emergence, Complexity, Experience, and the Embodied Mind

Zorn, Diana M. 31 August 2011 (has links)
The potential of a broad enactive approach in education has yet to be realized. This thesis contributes to the development of a well-rounded enactive educational theory and practice. This thesis argues that a broad enactive perspective has the potential to challenge, reframe and reconfigure problems, issues and practices in education in ways that improve teaching, learning and research communities. It establishes that a broad enactive approach as a theory of embodied mind, a dynamic co-emergence theory, and a method of examining human experience helps to realize the meaning, scope, and potential of enactive education. It takes as its point of departure Dewey’s broad enactive philosophy of mind, cognition, embodiment, experience, and dynamic co-emergence. It shows, through an examination of an actual public classroom encounter, that a broad enactive approach has the potential to reconfigure responsibility, ethics and justice in education. It demonstrates using a case study of the enactment of impostor feelings in higher education how a broad enactive approach to education as the potential to reconfigure teaching, learning and research practices.
73

Goal-directed Imitation In Pre-school And Elementary School Children

Fallahzadeh, Pardis 01 September 2011 (has links) (PDF)
Imitation is a fundamental way of acquiring knowledge in human development. In their theory of goal-directed imitation (GOADI), Wohlschl&auml / ger et al. (2003) divide the representation of observed movements into hierarchically organized aspects the highest of which is usually the goal. In a face-to-face imitation task young children usually copy the (spatial) goal of the body movement in terms of perceptual mirror symmetry rather than match them conceptually onto their own body, as adults do. We refer to these imitation schemes as &ldquo / mirroring&rdquo / and &ldquo / matching&rdquo / respectively. In the present study, we investigate the effects of age and perspective of the child with respect to the experimenter (0&deg / , 90&deg / , 180&deg / ) in two imitation tasks, a hand-to-ear and a cup-grasping task. Moreover, we evaluate the developmental changes in the imitative behavior of children from a dynamical systems perspective. Children were supposed to imitate the movements of the experimenter. Tasks were conducted on 4.5- to 11-year-old Iranian pre-school and elementary school children (81 female, 84 male). Imitation scores for the spatial goal were analyzed in terms of mirroring or matching. Imitation schemes varied according to age and perspective in both tasks. Overall, older children&rsquo / s imitations of movements were more adult-like as established by an adult Iranian control group than those of the younger ones. They rather matched than mirrored observed movements. In the 180&deg / and 90&deg / conditions the mirroring scheme was predominant, but in 0&deg / matching was predominant. GOADI was confirmed / however it was qualified by the child&#039 / s perspective on the experimenter. Children&rsquo / s imitations showed a non-linear shift from perceptually-based mirroring to conceptually-based matching of observed movements onto their own body. This shift happens between 6 and 8-9 years of age. The amount of matching depends not only on age but also on control parameters such as spatial perspective, task demands, and exposure.
74

Integration of database technology and multibody system analysis

Tisell, Claes January 2000 (has links)
<p>The design process includes many different activities inwhich various computational mechanics tools are used forbehaviour modelling of mechanical systems and their buildingblocks, e.g. machine elements. These tools usually supportlarge and complex models and they produce large quantities ofdata with a high degree of complexity. In these situations,efficient data management and the ability to search and sharedata are important issues to achieve an efficient designprocess. Today, this ability is usually not supported by theindividual applications even though this probably would improveand facilitate the ability to search for data on a higher levelin the engineering information system.</p><p>This work investigates the ability of searching andcomparing analysis data within behaviour models of technicalsystems as well as over the analysis results. This is done byinvestigating the potential benefits of integrating moderndatabase technology with a multibody system (MBS) analysissoftware in the same manner that has been successfully done forbusiness and administrative applications. This has resulted inan implemented pilot system, named MECHAMOS, that integratesthe main-memory resident object-relational database managementsystem (DBMS) AMOSwith the symbolic multibody system (MBS)software SOPHIA operating in MapleV. This provides MECHAMOSwith both symbolic and numeric mathematical capabilities forMBS analysis and data management capabilities to search andcompare engineering data in the database.</p><p>The approach, making data managing tools available in acomputer aided engineering software, considerably improves theanalysis of technical systems. The analysis is brought to ahigher level through the available query language and thedesired data is specified, fairly intuitively, in a query. Whenthe query is processed, the DBMS knows how to retrieve andautomatically derive the required data. As shown in someexamples, the ability to search over stored and derived data inthe database is not restricted to a single MBS-model inMECHAMOS. Because of the implemented materialisation handling,it is also possible to search, combine, and compare data fromseveral simulation results which are based on several differentmodels in the database. This extends the ability to performoptimisation from a traditional parameter study to thepossibility to analyse and compare different technical conceptsthrough the query language and hereby retrieve those conceptsthat fulfil certain requirements. If submodel techniques aresupported, queries over a set of components in the databasewould automatically create, analyse and compare the possibleconcepts. This would assist the designer in choosing the bestcomponents for a design.</p>
75

An Integrated Building Water Management Model for Green Building

Joustra, Caryssa 01 July 2010 (has links)
The U.S. Green Building Council (USGBC) is the developer of the Leadership in Energy and Environmental Design (LEED™) green building scoring system. On first inspection of LEED points, few address water efficiency. However, water management encompasses other points beyond the Water Efficiency (WE) category. In general, the industry is apt to take a somewhat compartmentalized approach to water management. The use of alternative water sources or the reuse of wastewater significantly complicates the water budget picture. A total water management systems approach, taking into consideration water from various sources, both inside and outside the building, should be implemented in order to devise a strategy for optimal reduction of potable water consumption and wastewater generation. Using the STELLA software to create an integrated building water management (IBWM) model provides stakeholders with a tool to evaluate potential water savings under dynamic conditions for a specific project site. Data collection for IBWM model calibration also shows that water consumption trends are unique to each project, and using LEED assumptions about water usage can overestimate or underestimate potential water savings.
76

Embodying Social Practice: Dynamically Co-Constituting Social Agency

Dunst, Brian W. 01 January 2013 (has links)
Theories of cognition and theories of social practices and institutions have often each separately acknowledged the relevance of the other; but seldom have there been consistent and sustained attempts to synthesize these two areas within one explanatory framework. This is precisely what my dissertation aims to remedy. I propose that certain recent developments and themes in philosophy of mind and cognitive science, when understood in the right way, can explain the emergence and dynamics of social practices and institutions. Likewise, the view I construct explains how social practices and institutions shape the character of cognition of their constituent agents. Moreover, I explain both cognitive and social agency under the single explanatory framework provided by Dynamic Systems Theory. Drawing upon the phenomenological tradition, "embodied, "extended", "embedded", "enactive", and "ecological" approaches to cognition, as well as the conceptual resources of Dynamic Systems Theory, I construct a theory of agency that sees cognitive and social agents as far-from-equilibrium, open, recursively self-maintenant dynamic systems. Depending on the specifics of concrete circumstances, such systems, which I call "Dynamic Embodied Agents" (or DEAs), may develop and possess emergent capacities for error-detection, flexible learning, normative behavior, representation, self-reflection, various modes of pattern-recognition, a temporal sense of self, and even moral responsibility. Some such systems are also sensitive to perceived social influences (practices and institutions); while reciprocally constituting and causally affecting them.
77

Emergence of comprehension of Spanish second language requests

Sauveur, Robert Paul 23 October 2013 (has links)
This dissertation examines the developmental trajectory of online processing toward second language (L2) pragmatic comprehension. This goal stems from two shortcomings of previous research: (1) approaching L2 pragmatics as the acquisition of discrete phenomena through progressive stages (see Kasper, 2009), and (2) focusing narrowly on production. Building upon previous L2 pragmatic comprehension work (Carrell, 1981; P. García, 2004; Taguchi, 2005, 2007, 2008a, 2008b, 2011a, 2011b; Takahashi & Roitblat, 1994), the current study investigates the development of L2 Spanish request speech act comprehension by native English-speaking adult learners. The analysis involves accuracy, comprehension speed and the relationship between the two dimensions across three levels of directness over a 13-week period. Previous research was informed by skill acquisition theories (Anderson & Lebiere, 1998) to account for increased accuracy and decreased speed over time. Here, further analysis is based on Complexity Theory / Dynamic Systems Theory (CT/DST) (Larsen-Freeman, 1997; Larsen-Freeman & Cameron, 2008a; de Bot, Lowie, & Verspoor, 2007; Ellis, et al., 2009; Verspoor, de Bot, & Lowie, 2011) to account for the seemingly chaotic results often found in L2 research. The findings of the current study show significant overall improvement in accuracy and speed of Spanish request identification, and a moderate relationship between the two measures. However, the association between slower responses and higher accuracy in the current data contradicts skill acquisition theories. Rather, the theoretical framework of CT/DST provides a more authentic account of development. As such, the results indicate that the levels of request directness develop along distinct trajectories and timescales. Direct requests reflect higher accuracy and faster interpretation. While the most indirect level of requests shows the largest improvement in accuracy, the responses for these items are no faster at the end of the study than at the beginning. The development of conventionally indirect requests occupies a middle ground in terms of accuracy similar to direct requests and comprehension speed like implied items. Further findings reflect L2 pragmatic comprehension as a complex, dynamic system that emerges through the differential effects of predictor variables across measures and within sub-groups of participants based on proficiency improvement, motivation and response strategy. / text
78

Statistical Learning of Some Complex Systems: From Dynamic Systems to Market Microstructure

Tong, Xiao Thomas 27 September 2013 (has links)
A complex system is one with many parts, whose behaviors are strongly dependent on each other. There are two interesting questions about complex systems. One is to understand how to recover the true structure of a complex system from noisy data. The other is to understand how the system interacts with its environment. In this thesis, we address these two questions by studying two distinct complex systems: dynamic systems and market microstructure. To address the first question, we focus on some nonlinear dynamic systems. We develop a novel Bayesian statistical method, Gaussian Emulator, to estimate the parameters of dynamic systems from noisy data, when the data are either fully or partially observed. Our method shows that estimation accuracy is substantially improved and computation is faster, compared to the numerical solvers. To address the second question, we focus on the market microstructure of hidden liquidity. We propose some statistical models to explain the hidden liquidity under different market conditions. Our statistical results suggest that hidden liquidity can be reliably predicted given the visible state of the market. / Statistics
79

Statistical Computation for Problems in Dynamic Systems and Protein Folding

Wong, Samuel Wing Kwong 21 August 2013 (has links)
Inference for dynamic systems and conformational sampling for protein folding are two problems motivated by applied data, which pose computational challenges from a statistical perspective. Dynamic systems are often described by a set of coupled differential equations, and methods of parametric estimation for these models from noisy data can require repeatedly solving the equations numerically. Many of these models also lead to rough likelihood surfaces, which makes sampling difficult. We introduce a method for Bayesian inference on these models, using a multiple chain framework that exploits the underlying mathematical structure and interpolates the posterior to improve efficiency. In protein folding, a large conformational space must be searched for low energy states, where any energy function constructed on the states is at best approximate. We propose a method for sampling fragment conformations that accounts for geometric and energetic constraints, and explore ideas for folding entire proteins that account for uncertain energy landscapes and learning from data more effectively. These ingredients are combined into a framework for tackling the problem of generating improvements to protein structure predictions. / Statistics
80

Μελέτη της ευαισθησίας γραμμικών δυναμικών συστημάτων

Σταυράκογλου, Μιχαήλ 12 June 2015 (has links)
Η ευαισθησία των συστημάτων είναι ένα σημαντικό θέμα της Θεωρίας Συστημάτων, το οποίο καλύπτεται σε εισαγωγικό επίπεδο με αυτή την εργασία. Η ευαισθησία αφορά τις διαφορές ανάμεσα στο πραγματικό σύστημα και στο μαθηματικό μοντέλο: αν κάποιες παράμετροι διαφέρουν αρκετά ανάμεσα στο πραγματικό σύστημα και στο μαθηματικό μοντέλο και η συμπεριφορά του συστήματος εξαρτάται κατά μεγάλο βαθμό από αυτές τις παραμέτρους, τότε η χρησιμότητα του μαθηματικού μοντέλου θα είναι πολύ μικρή αν δεν γνωρίζουμε ταυτόχρονα την παραμετρική ευαισθησία του συστήματος, δηλαδή την επίδραση των μεταβολών των παραμέτρων πάνω στην δυναμική συμπεριφορά του συστήματος. Βασικό ρόλο παίζει η προσομοίωση των εξισώσεων ευαισθησίας κατάστασης. Καθορίζουμε αρχικά τις εξισώσεις ευαισθησίας κατάστασης για παραμέτρους τύπου α και δείχνουμε ότι οι συναρτήσεις ευαισθησίας κατάστασης ενός συνεχούς συστήματος με χρονικά αμετάβλητες παραμέτρους καθορίζονται πάντα από ένα γραμμικό σύστημα διαφορικών εξισώσεων με μηδενικές αρχικές συνθήκες. Στην συνέχεια θα επεκταθούμε και στην εύρεση των συναρτήσεων ευαισθησίας κατάστασης για την περίπτωση που έχουμε παραμέτρους τύπου β και θα δούμε ότι και εδώ οι εξισώσεις ευαισθησίας κατάστασης είναι πάντα γραμμικές και οι αρχικές συνθήκες είναι ή μηδέν ή μονάδα. Στη συνέχεια προχωράμε στην εύρεση των συναρτήσεων ευαισθησίας κατάστασης για την περίπτωση που έχουμε παραμέτρους τύπου λ, αφού δούμε πρώτα το πότε μπορούμε να χρησιμοποιήσουμε το μειωμένο ονομαστικό μοντέλο. Επί πλέον, εξετάζουμε εν συντομία και τον καθορισμό των εξισώσεων ευαισθησίας εξόδου. Για την περίπτωση που έχουμε να μελετήσουμε και να συγκρίνουμε την παραμετρική ευαισθησία συστημάτων ανοικτού και κλειστού βρόχου καθώς επίσης και στην σύνθεση συστημάτων "αναίσθητων" σε παραμετρικές μεταβολές, είναι αναγκαίο να έχουμε έναν ορισμό ευαισθησίας που να είναι ανεξάρτητος από την μορφή του σήματος εισόδου, αλλά να εξαρτάται μόνο από την δομή του συστήματος. Αυτή η απαίτηση ικανοποιείται με τους ορισμούς ευαισθησίας στο πεδίο συχνότητας, οι οποίοι βασίζονται στην συνάρτηση μεταφοράς ή στον πίνακα μεταφοράς του συστήματος. Εξετάζουμε τη συνάρτηση ευαισθησίας του Bode, τη συνάρτηση ευαισθησίας του Horowitz και τη συγκριτική συνάρτηση ευαισθησίας των Perkins και Cruz. Η τελευταία μπορεί να γενικευθεί και σε μη γραμμικά, χρονικά μεταβαλλόμενα συστήματα. / The sensitivity of systems is an important theme of Systems Theory, which is covered to an introductory level in this work. The sensitivity concerns differences between the real system and the mathematical model: if some parameters are quite different between the real system and the mathematical model and the behavior of the system depends strongly on these parameters, the utility of the mathematical model will be very little if we do not know both the parametric sensitivity of the system, i.e. the effect of changes in parameters on the dynamic behavior of the system. A key role is played by simulating the state sensitivity equations. First we determine the state of sensitivity equations for parameters of type a and show that the state of sensitivity functions of a continuous system with time invariant parameters are always determined by a linear system of differential equations with zero initial conditions. Then we expand and find the state sensitivity functions for the case where we have parameters of type b and we see that here the situation sensitivity equations are always linear and the initial conditions are zero. Then we move on finding state sensitivity functions for the type lambda parameters, after we look when the reduced nominal model can use. Moreover, we look briefly at the output sensitivity equations. In case we have to study and compare the parametric sensitivity of open and closed-loop systems as well as in the synthesis systems "unconscious" to parametric changes, it is necessary to have a definition of sensitivity that is independent of the input signal format, but can depend only on the structure of the system. This requirement is satisfied by the definitions of sensitivity in the frequency domain, which are based on the transfer function or the system operator panel. We examine the sensitivity function of Bode, the sensitivity function of Horowitz and the comparative context sensitivity of Perkins and Cruz. The latter can be generalized to nonlinear, time-varying systems.

Page generated in 0.1225 seconds