Bibliographies thématiques / First order dynamic

Littérature scientifique sur le sujet « First order dynamic »

Auteur : Grafiati
Publié le 10 mars 2023

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Articles de revues sur le sujet "First order dynamic"

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ÖZOĞUZ, BANU EBRU, YIĞIT GÜNDÜÇ et MERAL AYDIN. « DYNAMIC SCALING FOR FIRST-ORDER PHASE TRANSITIONS ». International Journal of Modern Physics C 11, no 03 (mai 2000) : 553–59. http://dx.doi.org/10.1142/s0129183100000468.

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The critical behavior in short time dynamics for the q = 6 and 7 state Potts models in two-dimensions is investigated. It is shown that dynamic finite-size scaling exists for first-order phase transitions.
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Bharadwaj, Shrikant R., et Clifton M. Schor. « Dynamic control of ocular disaccommodation : First and second-order dynamics ». Vision Research 46, no 6-7 (mars 2006) : 1019–37. http://dx.doi.org/10.1016/j.visres.2005.06.005.

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Sanner, Scott, et Kristian Kersting. « Symbolic Dynamic Programming for First-order POMDPs ». Proceedings of the AAAI Conference on Artificial Intelligence 24, no 1 (4 juillet 2010) : 1140–46. http://dx.doi.org/10.1609/aaai.v24i1.7747.

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Partially-observable Markov decision processes (POMDPs) provide a powerful model for sequential decision-making problems with partially-observed state and are known to have (approximately) optimal dynamic programming solutions. Much work in recent years has focused on improving the efficiency of these dynamic programming algorithms by exploiting symmetries and factored or relational representations. In this work, we show that it is also possible to exploit the full expressive power of first-order quantification to achieve state, action, and observation abstraction in a dynamic programming solution to relationally specified POMDPs. Among the advantages of this approach are the ability to maintain compact value function representations, abstract over the space of potentially optimal actions, and automatically derive compact conditional policy trees that minimally partition relational observation spaces according to distinctions that have an impact on policy values. This is the first lifted relational POMDP solution that can optimally accommodate actions with a potentially infinite relational space of observation outcomes.
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Dos Santos, Iguer Luis Domini, Sanket Tikare et Martin Bohner. « First-order nonlinear dynamic initial value problems ». International Journal of Dynamical Systems and Differential Equations 11, no 3/4 (2021) : 241. http://dx.doi.org/10.1504/ijdsde.2021.10040295.

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Bohner, Martin, Sanket Tikare et Iguer Luis Domini Dos Santos. « First-order nonlinear dynamic initial value problems ». International Journal of Dynamical Systems and Differential Equations 11, no 3/4 (2021) : 241. http://dx.doi.org/10.1504/ijdsde.2021.117358.

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Fu, Bin, et Qiongzhang Li. « The expressibility of first order dynamic logic ». Journal of Computer Science and Technology 7, no 3 (juillet 1992) : 268–73. http://dx.doi.org/10.1007/bf02946577.

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Pu, Yewen, Rastislav Bodik et Saurabh Srivastava. « Synthesis of first-order dynamic programming algorithms ». ACM SIGPLAN Notices 46, no 10 (18 octobre 2011) : 83–98. http://dx.doi.org/10.1145/2076021.2048076.

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Atici, F. Merdivenci, et D. C. Biles. « First order dynamic inclusions on time scales ». Journal of Mathematical Analysis and Applications 292, no 1 (avril 2004) : 222–37. http://dx.doi.org/10.1016/j.jmaa.2003.11.053.

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Mantin, Benny, Daniel Granot et Frieda Granot. « Dynamic pricing under first order Markovian competition ». Naval Research Logistics (NRL) 58, no 6 (12 juillet 2011) : 608–17. http://dx.doi.org/10.1002/nav.20470.

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Joshi, S., et R. Khardon. « Probabilistic Relational Planning with First Order Decision Diagrams ». Journal of Artificial Intelligence Research 41 (21 juin 2011) : 231–66. http://dx.doi.org/10.1613/jair.3205.

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Dynamic programming algorithms have been successfully applied to propositional stochastic planning problems by using compact representations, in particular algebraic decision diagrams, to capture domain dynamics and value functions. Work on symbolic dynamic programming lifted these ideas to first order logic using several representation schemes. Recent work introduced a first order variant of decision diagrams (FODD) and developed a value iteration algorithm for this representation. This paper develops several improvements to the FODD algorithm that make the approach practical. These include, new reduction operators that decrease the size of the representation, several speedup techniques, and techniques for value approximation. Incorporating these, the paper presents a planning system, FODD-Planner, for solving relational stochastic planning problems. The system is evaluated on several domains, including problems from the recent international planning competition, and shows competitive performance with top ranking systems. This is the first demonstration of feasibility of this approach and it shows that abstraction through compact representation is a promising approach to stochastic planning.
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Thèses sur le sujet "First order dynamic"

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Duke, Elizabeth R. « Solving higher order dynamic equations on time scales as first order systems ». Huntington, WV : [Marshall University Libraries], 2006. http://www.marshall.edu/etd/descript.asp?ref=653.

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Park, Nam Seog. « A connectionist representation of first-order formulae with dynamic variable binding ». Thesis, University of Edinburgh, 1997. http://hdl.handle.net/1842/30624.

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The relationship between symbolicism and connectionism has been one of the major issues in recent Artificial Intelligence research. An increasing number of researchers from each side have tried to adopt desirable characteristics of the other. These efforts have produced a number of different strategies for interfacing connectionist and symbolic AI. One of them is connectionist and symbol processing which attempts to replicate symbol processing functionalaties using connectionist components. In this direction, this thesis develops a connectionist inference architecture which performs standard symbolic inference on a subclass of first-order predicate calculus. Our primary interest is in understanding how formulas which are described in a limited form of first-order predicate calculus may be implemented using a connectionist architecture. Our chosen knowledge representation scheme is a subset of first-order Horn clause expressions which is a set of universally quantified expressions in first-order predicate calculus. As a focus of attention we are developing techniques for compiling first-order Horn clause expressions into a connectionist network. This offers practical benefits but also forces limitations on the scope of the compiled system, since we are, in fact, merging an interpreter into the connectionist networks. The compilation process has to take into account not only first-order Horn clause expressions themselves but also the strategy which we intend to use for drawing inferences from the. Thus, this thesis explores the extent to which this type of a translation can build a connectionist inference model to accommodate desired symbolic inference. This work first involves constructing efficient connectionist mechanisms to represent symbol components, dynamic bindings, basic symbolic inference procedures, and devising a set of algorithms which automatically translates input descriptions to neural networks using the above connectionist mechanisms. These connectionist mechanisms are built by taking an existing temporal synchrony mechanism and extending it further to obtain desirable features to represent and manipulate basic symbol structures. The existing synchrony mechanism represents dynamic bindings very efficiently using temporal synchronous activity between neuron elements but it has fundamental limitations in supporting symbolic inference. The extension addresses these limitations.
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Kutahyalioglu, Aysen. « Oscillation Of Second Order Dynamic Equations On Time Scales ». Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605380/index.pdf.

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During the last decade, the use of time scales as a means of unifying and extending results about various types of dynamic equations has proven to be both prolific and fruitful. Many classical results from the theories of differential and difference equations have time scale analogues. In this thesis we derive new oscillation criteria for second order dynamic equations on time scales.
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Sforni, Lorenzo. « A First-Order Closed-loop Methodology for Nonlinear Optimal Control ». Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/21429/.

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This thesis is focused on state-of-art numerical optimization methods for nonlinear (discrete-time) optimal control. These challenging problems arise when dealing with complex tasks for autonomous systems (e.g. vehicles or robots) which require the generation of a trajectory that satisfies the system dynamics and, possibly, input and state constraints due to, e.g, actuator limits or safety region of operation. A general formulation is proposed that allows the implementation of different descent optimization algorithms on optimal control problems exploiting the beneficial effects of state feedback in terms of efficiency and stability. The main idea is the following: at each iteration a new (infeasible) state-input curve is conveniently updated by any descent method, e.g, gradient descent or Newton methods, then a nonlinear feedback controller maps the curve to a trajectory satisfying the dynamics. Thanks to its inherent flexibility, this strategy provides the opportunity to speed-up the resolution of optimization problems by conveniently choosing the descent method. This thesis proposes, for example, to exploit the Heavy-ball method to speed up the convergence. It is important to underline that this methodology enjoys recursive feasibility during the algorithm evolution, i.e. at each iteration a system trajectory is available. This feature is extremely important in real-time control schemes since it allows one to stop the algorithm at any iteration and yet have a (suboptimal) system trajectory. Furthermore, tasks which require the introduction of state and input constraints can be managed introducing an approximate barrier function which embeds the constraints within the cost function. The second main contribution of this thesis is an original Python toolbox developed in order to implement and compare different optimization methods. Moreover, thanks to a modular approach, with just few adjustments it is possible to change system, cost function and constraints.
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Zaidi, Atiya-tul-Hussain Mathematics &amp Statistics Faculty of Science UNSW. « Existence and uniqueness of solutions to non-linear first order dynamic equations on time scales ». Awarded by:University of New South Wales. Mathematics & ; Statistics, 2009. http://handle.unsw.edu.au/1959.4/44908.

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The theory of dynamic equations on time scales provides an important bridge between the fields of differential and difference equations. It is particularly useful in describing phenomena that possess a hybrid continuous-discrete behaviour in their growth, like many temperate--2one insect populations and crops. A dynamic equation on a time scale is a generalised. 'two-in-one' model, it serves as a differential equation for purely continuous domains and as a difference equation for purely discrete ones. The field of "dynamic equations on time scales" is about 20 years old. As such, much of the basic (yet very important) linear theory has been established, however the non-linear extensions are yet to be fully developed. This thesis aims to fill this gap by providing the foundational framework of non-linear results from which further lines of inquiry can be launched. This thesis answers several important questions regarding the qualitative and quantitative properties of solutions to non-linear dynamic equations on time scales. Namely, (i) When do solutions exist? (ii) If solutions exist, then are they unique? (iii) How can such solutions be closely approximated? (iv) How can we explicitly solve certain problems to extract their solutions? The methods employed to address the above questions include: dynamic inequalities; iterative techniques and the method of successive approximations; and the fixed point approaches of Banach and Schauder.
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Giorgidze, George. « First-class models : on a noncausal language for higher-order and structurally dynamic modelling and simulation ». Thesis, University of Nottingham, 2012. http://eprints.nottingham.ac.uk/12554/.

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The field of physical modelling and simulation plays a vital role in advancing numerous scientific and engineering disciplines. To cope with the increasing size and complexity of physical models, a number of modelling and simulation languages have been developed. These languages can be divided into two broad categories: causal and noncausal. Causal languages express a system model in terms of directed equations. In contrast, a noncausal model is formulated in terms of undirected equations. The fact that the causality can be left implicit makes noncausal languages more declarative and noncausal models more reusable. These are considered to be crucial advantages in many physical domains. Current, mainstream noncausal languages do not treat equational models as first-class values; that is, a model cannot be parametrised on other models or generated at simulation runtime. This results in very limited higher-order and structurally dynamic modelling capabilities, and limits the expressiveness and applicability of noncausal languages. This thesis is about a novel approach to the design and implementation of noncausal languages with first-class models supporting higher-order and structurally dynamic modelling. In particular, the thesis presents a language that enables: (1) higher-order modelling capabilities by embedding noncausal models as first-class entities into a functional programming language and (2) efficient simulation of noncausal models that are generated at simulation runtime by runtime symbolic processing and just-in-time compilation. These language design and implementation approaches can be applied to other noncausal languages. This thesis provides a self-contained reference for such an undertaking by defining the language semantics formally and providing an in-depth description of the implementation. The language provides noncausal modelling and simulation capabilities that go beyond the state of the art, as backed up by a range of examples presented in the thesis, and represents a significant progress in the field of physical modelling and simulation.
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Heidarian, Alireza. « Study of the Static and Dynamic Magnetization across the First Order Phase Transition in FeRh Thin Films ». Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-198693.

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The equiatomic FeRh alloy undergoes a first-order phase transition from an antiferromagnetic (AFM) to a ferromagnetic (FM) state at about 370 K with a small thermal hysteresis of about 10 K around the phase transition. The transition is accompanied by a unit cell volume expansion about 1% in the c lattice parameter. During the transition the new phase nucleates in the matrix of the original phase by reaching the critical temperature followed by a growth in size upon increasing temperature further. Therefore, to understand the transition process with more details, it is desirable to investigate the nucleation and growth of both phases within the first order phase transition. In the present thesis the main focus is on the growth of FeRh thin films by means of Molecular Beam Epitaxy (MBE) technique and characterization of the magnetic and structural properties. To develop an understanding of the phase transformation in FeRh thin films the ways in which one can tune it were investigated. The following aspects concerning the FeRh system have been examined here: 1) influence of annealing temperature on the magnetic and structural response, 2) effect of film thickness on the first-order phase transition temperature as well as the saturation magnetization, 3) influence of chemical composition on the magnetic properties and 4) magnetic field-induced phase transition. To get insight to details of the transition process the magnetization dynamic has been addressed by performing Ferromagnetic resonance (FMR) experiment across the phase transition. FMR measurements determined the existence of two areas with different magnetic properties inside the film. A huge temperature difference for the beginning of the phase transition in comparison with the static magnetization measurement was observed for the equiatomic FeRh thin film prepared by MBE. Tuning of the AFM to FM phase transition in the FeRh thin film by means of low-energy/low fluence Ne+ ion irradiation was studied. Ion irradiation technique offers a quantitative control of the degree of chemical disorder by adjusting the ion fluence applied, while the penetration depth of the disordered phase can be adjusted by the ion-energy. The main results of ion irradiation are the shifting of the phase transition temperature to lower temperature and irradiation with 3×1014 ion/cm2 leads to the disappearance the AFM phase completely.
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Bertone, Armando. « Static and dynamic motion aftereffects of first- and second-order motion in central and peripheral fields of vision ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape15/PQDD_0003/MQ39441.pdf.

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Baradaran, Amir R. « Development and Implementation of a Preconditioner for a Five-Moment One-Dimensional Moment Closure ». Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32225.

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This study is concerned with the development and implementation of a preconditioner for a set of hyperbolic partial differential equations resulting from a new 5-moment closure for the prediction of gas flows both in and out of local equilibrium. This new 5-moment closure offers a robust and efficient system of first-order hyperbolic partial differential equations that has proven to provide an accurate treatment of one-dimensional gases, both in and for significant departures from local thermodynamic equilibrium. However, numerical computations using this model have proven to be difficult as a result of a singularity in the closing flux of the system. This also causes infinitely large wavespeeds in the system. The main goal of this work is to mitigate these numerical issues. Since the solution of a hyperbolic system is characterized by the waves of the system, one could suggest to scale these wavespeeds to remove the arbitrarily large speeds without altering the solution of the system. To accomplish this, this work starts with a detailed study of the behaviour of the system’s wavespeeds, given by the eigenvalues of the flux Jacobian of the system. Since, it is not possible to solve for these eigenvalues explicitly, it is suggested to approximate them by interpolation between the few states at which these waves can be solved for explicitly. With an estimate for the wavespeeds, the nature of the singularity in the system can be analyzed mathematically. The results of this mathematical analysis are used to develop a preconditioner matrix to remove the singularity from the model. To implement the proposed preconditioned model numerically, a centred-difference scheme with artificial dissipation is proposed. A dual-time-stepping strategy is developed and implemented with implicit Euler time marching for both physical and pseudo time iteration. This dual-time treatment allows the preconditioned system to remain applicable to time-accurate problems and is found to greatly increase the robustness of the solution of the steady-state problems. Solutions to several canonical problems for both continuum and non-equilibrium flow are computed and comparisons are made to classical models.
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Heidarian, Alireza [Verfasser], Jürgen [Akademischer Betreuer] Faßbender et Thomas [Akademischer Betreuer] Thomson. « Study of the Static and Dynamic Magnetization across the First Order Phase Transition in FeRh Thin Films / Alireza Heidarian. Betreuer : Jürgen Faßbender. Gutachter : Jürgen Faßbender ; Thomas Thomson ». Dresden : Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://d-nb.info/1088185940/34.

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Livres sur le sujet "First order dynamic"

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Kiviet, Jan F. Higher-order asymptotic expansions of the least-squares estimation bias in first-order dynamic regression models. Bristol : University of Bristol, Department of Economics, 1996.

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Hughes, Terence J. Holistic ice sheet modeling : A first-order approach. Hauppauge, N.Y : Nova Science Publishers, 2011.

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Padhi, Seshadev, John R. Graef et P. D. N. Srinivasu. Periodic Solutions of First-Order Functional Differential Equations in Population Dynamics. New Delhi : Springer India, 2014. http://dx.doi.org/10.1007/978-81-322-1895-1.

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Subbotin, A. I. Generalized solutions of first-order PDEs : The dynamical optimization perspective. Boston : Birkhäuser, 1995.

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Workshop on Dynamics of First Order Phase Transitions (1992 Jülich, Germany). Workshop on dynamics of first order phase transitions : HLRZ, KFA Jülich, Germany, June 1-3, 1992. Singapore : World Scientific, 1992.

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Spectral analysis, differential equations, and mathematical physics : A festschrift in honor of Fritz Gesztesy's 60th birthday. Providence, Rhode Island : American Mathematical Society, 2013.

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Southeast Geometry Seminar (15th 2009 University of Alabama at Birmingham). Geometric analysis, mathematical relativity, and nonlinear partial differential equations : Southeast Geometry Seminars Emory University, Georgia Institute of Technology, University of Alabama, Birmingham, and the University of Tennessee, 2009-2011. Sous la direction de Ghomi Mohammad 1969-. Providence, Rhode Island : American Mathematical Society, 2013.

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Back, Kerry E. Dynamic Portfolio Choice. Oxford University Press, 2017. http://dx.doi.org/10.1093/acprof:oso/9780190241148.003.0009.

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The first‐order condition for optimal portfolio choice is called the Euler equation. Optimal consumption can be computed by a static approach in a dynamic complete market and by orthogonal projection for a quadratic utility investor. Dynamic programming and the Bellman equation are explained. The envelope condition and hedging demands are explained. Investors with CRRA utility have CRRA value functions. Whether the marginal value of wealth is higher for a CRRA investor in good states or in bad states depends on whether risk aversion is less than or greater than 1. With IID returns, the optimal portfolio for a CRRA investor is the same as the optimal portfolio in a single‐period model.
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Teece, David J., et Sohvi Heaton, dir. The Oxford Handbook of Dynamic Capabilities. Oxford University Press, 2015. http://dx.doi.org/10.1093/oxfordhb/9780199678914.001.0001.

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This handbook is currently in development, with individual articles publishing online in advance of print publication. At this time, we cannot add information about unpublished articles in this handbook, however the table of contents will continue to grow as additional articles pass through the review process and are added to the site. Please note that the online publication date for this handbook is the date that the first article in the title was published online. For more information, please read the site FAQs. In order to make quality strategic decisions, managers need a deep understanding of industry dynamics and enterprise capabilities. In this book, we present a conceptual framework that will help executives lead their organizations in highly competitive global markets. For some, it will change frames of reference and accepted priorities in terms of what’s important for the enterprise to build, own, and manage. Management theory is young and fragmented, and generally not much of a guide for executives, except around certain narrow issues. The framework presented in this volume can be helpful with the big-picture issues. To be useful, a theoretical framework must be flexible enough to provide guidance in a variety of situations. However, the theory must not be so general that it fails to speak to practical management problems. Another useful attribute is parsimony, so that an overwhelming number of variables don’t render analysis an impossible task. This book includes a number of essays about the Dynamic Capabilities Framework (Teece et al., 1990, 1997; Teece, 2007), which increasingly provides an intellectual infrastructure for both theoretical and applied analyses of strategic management and other issues facing business decision makers. Since 2006, articles concerning dynamic capabilities have been published in business and management journals at a rate of more than 100 per year (Di Stefano et al., 2010). And an increasing number of these articles contain new empirical research validating the Dynamic Capabilities approach to competitive advantage. A broad panoply of scholars and executives are contributing to the further development of this framework. This book summarizes and integrates many of these contributions, and this introduction will introduce some of the major themes of the chapters that follow.
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Miyashita, Seiji. Collapse of Metastability : Dynamics of First-Order Phase Transition. Springer, 2022.

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Chapitres de livres sur le sujet "First order dynamic"

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Georgiev, Svetlin G. « First Order Dynamic Inclusions ». Dans Fuzzy Dynamic Equations, Dynamic Inclusions, and Optimal Control Problems on Time Scales, 435–514. Cham : Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-76132-5_7.

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Gergely, Tamás, et László Úry. « Dynamic Logic Generated by Extension ». Dans First-Order Programming Theories, 171–78. Berlin, Heidelberg : Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/978-3-642-58205-9_14.

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Bohner, Martin, et Allan Peterson. « First Order Linear Equations ». Dans Dynamic Equations on Time Scales, 51–79. Boston, MA : Birkhäuser Boston, 2001. http://dx.doi.org/10.1007/978-1-4612-0201-1_2.

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Géczy, Peter, Shiro Usui et Ján Chmúrny. « First Order Dynamic Instance Selection ». Dans The State of the Art in Computational Intelligence, 74–77. Heidelberg : Physica-Verlag HD, 2000. http://dx.doi.org/10.1007/978-3-7908-1844-4_13.

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Georgiev, Svetlin G. « First Order Fuzzy Dynamic Equations ». Dans Fuzzy Dynamic Equations, Dynamic Inclusions, and Optimal Control Problems on Time Scales, 137–203. Cham : Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-76132-5_2.

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Gergely, Tamás, et László Úry. « Is Temporal Logic Expressible in Dynamic Logic ? » Dans First-Order Programming Theories, 243–45. Berlin, Heidelberg : Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/978-3-642-58205-9_20.

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Gergely, Tamás, et László Úry. « Is Dynamic Logic Expressible in Temporal Logic ? » Dans First-Order Programming Theories, 247–61. Berlin, Heidelberg : Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/978-3-642-58205-9_21.

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Ognjanović, Zoran, Aleksandar Perović et Dragan Doder. « A First-Order Dynamic Probability Logic ». Dans Lecture Notes in Computer Science, 461–72. Berlin, Heidelberg : Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-39091-3_39.

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Georgiev, Svetlin G. « Stability for First-Order Functional Dynamic Equations ». Dans Functional Dynamic Equations on Time Scales, 161–254. Cham : Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-15420-2_5.

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Georgiev, Svetlin G. « Oscillations of First-Order Functional Dynamic Equations ». Dans Functional Dynamic Equations on Time Scales, 255–345. Cham : Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-15420-2_6.

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Actes de conférences sur le sujet "First order dynamic"

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Pu, Yewen, Rastislav Bodik et Saurabh Srivastava. « Synthesis of first-order dynamic programming algorithms ». Dans the 2011 ACM international conference. New York, New York, USA : ACM Press, 2011. http://dx.doi.org/10.1145/2048066.2048076.

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Mohammadi, Keyvan, et Andrea L’Afflitto. « A Continuous First-Order Sliding Mode Control Law ». Dans ASME 2017 Dynamic Systems and Control Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/dscc2017-5082.

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Sliding mode control is a technique to design robust feedback control laws. In its classical formulation, this approach involves discontinuous controls that arise several theoretical and practical challenges, such as the existence of non-unique solutions of nonlinear differential equations and chattering. Numerous variations of the sliding mode control architecture, such as the higher-order sliding mode method, have been presented to overcome these issues. In this paper, we present an alternative sliding mode control architecture that involves Hölder continuous feedback control laws, is simpler to implement than other non-classical nonlinear robust control techniques, guarantees robustness and uniform asymptotic stability of the closed-loop system, and ensures both existence and uniqueness of the closed-loop system’s trajectory. Our results are applied to design a robust nonlinear observer in the same form as the Walcott and Żak observer. Moreover, a numerical example illustrates our theoretical results and compares the proposed control law to the classical sliding mode control, the second order sliding mode control, and the super-twisting control.
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Yan, Lei, et K. Krishnamurthy. « Motion Planning for Dynamic Systems Using First-Order Logic ». Dans ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-33465.

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The problem of motion planning for a class of dynamic systems is considered in this study. A knowledge-based approach is used to determine the initial conditions that will yield a certain desired state of the dynamic system. The search space is limited by using a set of rules because reasoning about dynamic systems is basically searching an infinite space. In this study, first-order logic is used for knowledge representation and reasoning. The methodology is applied to playing a pool game. The dynamics of the motion of the balls are complicated and significant expertise is required to know how to strike the balls. Simulated results presented show how the rules help in finding the appropriate strategies for playing the game.
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Liu, Sijia, Pin-Yu Chent, Indika Rajapakse et Alfred Hero. « FIRST-ORDER BIFURCATION DETECTION FOR DYNAMIC COMPLEX NETWORKS ». Dans ICASSP 2018 - 2018 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP). IEEE, 2018. http://dx.doi.org/10.1109/icassp.2018.8461400.

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Scheu, H., J. Busch et W. Marquardt. « Nonlinear distributed dynamic optimization based on first order sensitivities ». Dans 2010 American Control Conference (ACC 2010). IEEE, 2010. http://dx.doi.org/10.1109/acc.2010.5531587.

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Di, Bolei, et Andrew Lamperski. « Local First-Order Algorithms for Constrained Nonlinear Dynamic Games ». Dans 2020 American Control Conference (ACC). IEEE, 2020. http://dx.doi.org/10.23919/acc45564.2020.9147602.

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Venson, Giuliano Gardolinski, et Jose´ Eduardo Mautone Barros. « Turbocharger Dynamic Analysis Using First Order System Step Response ». Dans ASME Turbo Expo 2009 : Power for Land, Sea, and Air. ASMEDC, 2009. http://dx.doi.org/10.1115/gt2009-59822.

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This work presents the dynamic modeling of an automotive turbocharger in a hot gas test stand. The objective is to develop a methodology to determine the main turbocharger dynamic properties as moment of inertia, response time, static gain constant, frequency gain amplitude and phase shift. The turbocharger used is the Master Power APL-240 set. The moment of inertia is obtained through the deceleration curve from an instantaneous fuel cut-off in the combustion chamber. The response time and static gain constant, as well the frequency gain amplitude and phase shift curves in function of a signal frequency, are obtained through a step variation. The turbocharger is modeled as a first order system. It is also presented a turbocharger sine excitation by the combustion chamber, generating a rotational speed sine signal output that simulates an engine intermittent acceleration. The rotational speed signal frequency gain and phase shift are compared to the values obtained in the step curves. The rotational speed frequency gain amplitude and phase shift modeled through the step test presents deviation of 16% and 13%, respectively, from the values from sine test.
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Occhipinti Liberman, Andrés, et Rasmus Kræmmer Rendsvig. « Decidability Results in First-Order Epistemic Planning ». Dans Twenty-Ninth International Joint Conference on Artificial Intelligence and Seventeenth Pacific Rim International Conference on Artificial Intelligence {IJCAI-PRICAI-20}. California : International Joint Conferences on Artificial Intelligence Organization, 2020. http://dx.doi.org/10.24963/ijcai.2020/575.

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Propositional Dynamic Epistemic Logic (DEL) provides an expressive framework for epistemic planning, but lacks desirable features that are standard in first-order planning languages (such as problem-independent action representations via action schemas). A recent epistemic planning formalism based on First-Order Dynamic Epistemic Logic (FODEL) combines the strengths of DEL (higher-order epistemics) with those of first-order languages (lifted representation), yielding benefits in terms of expressiveness and representational succinctness. This paper studies the plan existence problem for FODEL planning, showing that while the problem is generally undecidable, the cases of single-agent planning and multi-agent planning with non-modal preconditions are decidable.
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Etessami, Kousha. « Dynamic tree isomorphism via first-order updates to a relational database ». Dans the seventeenth ACM SIGACT-SIGMOD-SIGART symposium. New York, New York, USA : ACM Press, 1998. http://dx.doi.org/10.1145/275487.275514.

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Boscolo, Marco, et Ranjan Banerjee. « Dynamic Stiffness Formulation for Plates Using First Order Shear Deformation Theory ». Dans 51st AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference
18th AIAA/ASME/AHS Adaptive Structures Conference
12th. Reston, Virigina : American Institute of Aeronautics and Astronautics, 2010. http://dx.doi.org/10.2514/6.2010-3033.

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Rapports d'organisations sur le sujet "First order dynamic"

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Jason, Andrew J. First-order beam dynamics and RF parameters for the PSR short-bunch ("pulse-stacking") mode. Office of Scientific and Technical Information (OSTI), janvier 2013. http://dx.doi.org/10.2172/1060895.

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Kimhi, Ayal, Barry Goodwin, Ashok Mishra, Avner Ahituv et Yoav Kislev. The dynamics of off-farm employment, farm size, and farm structure. United States Department of Agriculture, septembre 2006. http://dx.doi.org/10.32747/2006.7695877.bard.

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Objectives: (1) Preparing panel data sets for both the United States and Israel that contain a rich set of farm attributes, such as size, specialization, and output composition, and farmers’ characteristics such as off-farm employment status, education, and family composition. (2) Developing an empirical framework for the joint analysis of all the endogenous variables of interest in a dynamic setting. (3) Estimating simultaneous equations of the endogenous variables using the panel data sets from both countries. (4) Analyzing, using the empirical results, the possible effects of economic policies and institutional changes on the dynamics of the farm sector. An added objective is analyzing structural changes in farm sectors in additional countries. Background: Farm sectors in developed countries, including the U.S. and Israel, have experienced a sharp decline in their size and importance during the second half of the 20th century. The overall trend is towards fewer and larger farms that rely less on family labor. These structural changes have been a reaction to changes in technology, in government policies, and in market conditions: decreasing terms of trade, increasing alternative opportunities, and urbanization pressures. As these factors continue to change, so does the structure of the agricultural sector. Conclusions: We have shown that all major dimensions of structural changes in agriculture are closely interlinked. These include farm efficiency, farm scale, farm scope (diversification), and off-farm labor. We have also shown that these conclusions hold and perhaps even become stronger whenever dynamic aspects of structural adjustments are explicitly modeled using longitudinal data. While the results vary somewhat in the different applications, several common features are observed for both the U.S. and Israel. First, the trend towards the concentration of farm production in a smaller number of larger farm enterprises is likely to continue. Second, at the micro level, increased farm size is negatively associated with increased off-farm labor, with the causality going both ways. Third, the increase in farm size is mostly achieved by diversifying farm production into additional activities (crops or livestock). All these imply that the farm sector converges towards a bi-modal farm distribution, with some farms becoming commercial while the remaining farm households either exit farming altogether or continue producing but rely heavily on off-farm income. Implications: The primary scientific implication of this project is that one should not analyze a specific farm attribute in isolation. We have shown that controlling for the joint determination of the various farm and household attributes is crucial for obtaining meaningful empirical results. The policy implications are to some extent general but could be different in the two countries. The general implication is that farm policy is an important determinant of structural changes in the farm sector. For the U.S., we have shown the different effects of coupled and decoupled (direct) farm payments on the various farm attributes, and also shown that it is important to take into account the joint farm-household decisions in order to conduct a meaningful policy analysis. Only this kind of analysis explains the indirect effect of direct farm payments on farm production decisions. For Israel, we concluded that farm policy (or lack of farm policy) has contributed to the fast structural changes we observed over the last 25 years. The sharp change of direction in farm policy that started in the early 1980s has accelerated structural changes that could have been smoother otherwise. These accelerated structural changes most likely lead to welfare losses in rural areas.
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Borgwardt, Stefan, Marcel Lippmann et Veronika Thost. Temporal Query Answering w.r.t. DL-Lite-Ontologies. Technische Universität Dresden, 2013. http://dx.doi.org/10.25368/2022.195.

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Ontology-based data access (OBDA) generalizes query answering in relational databases. It allows to query a database by using the language of an ontology, abstracting from the actual relations of the database. For ontologies formulated in Description Logics of the DL-Lite family, OBDA can be realized by rewriting the query into a classical first-order query, e.g. an SQL query, by compiling the information of the ontology into the query. The query is then answered using classical database techniques. In this report, we consider a temporal version of OBDA. We propose a temporal query language that combines a linear temporal logic with queries over DL-Litecore-ontologies. This language is well-suited for expressing temporal properties of dynamical systems and is useful in context-aware applications that need to detect specific situations. Using a first-order rewriting approach, we transform our temporal queries into queries over a temporal database. We then present three approaches to answering the resulting queries, all having different advantages and drawbacks.
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Gallien, Max, Giovanni Occhiali et Hana Ross. An Overlooked Market : Loose Cigarettes, Informal Vendors, and Their Implications for Tobacco Taxation. Institute of Development Studies, février 2023. http://dx.doi.org/10.19088/ictd.2023.004.

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Recent years have seen the development of a substantial literature on tobacco taxation that has both noted its effectiveness as a tobacco control tool, and provided modelling of its implications. However, studies of tobacco taxation and tobacco consumption have largely ignored a crucial aspect of the market for cigarettes in many low- and middle-income countries – the prevalence of loose (single) cigarettes being sold, rather than cigarette packs. We argue that ignoring this market leaves room for unexpected dynamics and unintended policy effects. We develop this argument by establishing four aspects of the market for loose cigarettes. First, we show that it is sizeable and widespread. Second, we note that it has a consumer base that is on average poorer and younger than the overall population of smokers. Third, we show that the price dynamics for loose cigarettes are different to those for packs, that the price for a loose cigarette is typically higher than the equivalent per-cigarette price of a cigarette bought in a pack, and that the price of loose cigarettes and cigarette packs do not always move in parallel. Fourth, based on these dynamics, we show how the features of the loose cigarette market can affect the effectiveness of tobacco control policy, and in particular tobacco taxation. For example, we highlight that insufficient attention to the market for loose cigarettes might lead to a lower than anticipated effect of tax increases on demand, or might result in tax increases not being passed on to the consumers of loose cigarettes at all. Consequently, in order to ensure that tobacco tax increases immediately feed through to all consumers, policymakers in countries with markets for loose cigarettes should prioritise large rather than incremental tax increases.
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Regan, Jack, et Robin Zevotek. Evaluation of the Thermal Conditions and Smoke Obscuration of Live Fire Training Fuel Packages. UL Firefighter Safety Research Institute, mars 2019. http://dx.doi.org/10.54206/102376/karu4002.

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Firefighters routinely conduct live fire training in an effort to prepare themselves for the challenges of the fire ground. While conducting realistic live fire training is important, it also carries inherent risks. This is highlighted by several live fire training incidents in which an inappropriate fuel load contributed to the death of participants. NFPA 1403: Standard on Live Fire Training Evolutions was first established in response to a live fire training incident in which several firefighters died. Among the stipulations in NFPA 1403 is that the fuel load shall be composed of wood-based fuels. The challenge of balancing safety with fidelity has led instructors to explore a variety of different methods to create more realistic training conditions. A series of experiments was conducted in order to characterize common training fuels, compare these training fuels to furnishings, and examine the performance of these training fuels in a metal container prop. Heat release rate (HRR) characterization of training fuels indicated that wood-based training fuels had a constant effective heat of combustion. Depending on the method used, this value was between 13.6 and 13.9 MJ/kg. This indicates that, even in engineered wood products, wood is the primary material responsible for combustion. In order to further explore the conclusions from the HRR testing, additional experiments were conducted in an L-shaped metal training prop. The results of these experiments highlighted a number of considerations for firefighter training. Thermal conditions consistent with “realistic fires” could be produced using NFPA 1403 compliant fuels, and in fact the thermal conditions produced by larger wood-based fuel packages were more severe than those produced by fuel packages with a small amount of synthetic fuel. The fuel package used in training evolutions should reflect the training prop or building being used, the available ventilation, and the intended lesson. Fuel load weight and orientation are both important considerations when designing a fuel package. The training considerations drawn from this report will help to increase firefighters’ understanding of fire dynamics, and help instructors better understand fuel packages and the fire dynamics that they produce.
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Wu, Yingjie, Selim Gunay et Khalid Mosalam. Hybrid Simulations for the Seismic Evaluation of Resilient Highway Bridge Systems. Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, novembre 2020. http://dx.doi.org/10.55461/ytgv8834.

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Bridges often serve as key links in local and national transportation networks. Bridge closures can result in severe costs, not only in the form of repair or replacement, but also in the form of economic losses related to medium- and long-term interruption of businesses and disruption to surrounding communities. In addition, continuous functionality of bridges is very important after any seismic event for emergency response and recovery purposes. Considering the importance of these structures, the associated structural design philosophy is shifting from collapse prevention to maintaining functionality in the aftermath of moderate to strong earthquakes, referred to as “resiliency” in earthquake engineering research. Moreover, the associated construction philosophy is being modernized with the utilization of accelerated bridge construction (ABC) techniques, which strive to reduce the impact of construction on traffic, society, economy and on-site safety. This report presents two bridge systems that target the aforementioned issues. A study that combined numerical and experimental research was undertaken to characterize the seismic performance of these bridge systems. The first part of the study focuses on the structural system-level response of highway bridges that incorporate a class of innovative connecting devices called the “V-connector,”, which can be used to connect two components in a structural system, e.g., the column and the bridge deck, or the column and its foundation. This device, designed by ACII, Inc., results in an isolation surface at the connection plane via a connector rod placed in a V-shaped tube that is embedded into the concrete. Energy dissipation is provided by friction between a special washer located around the V-shaped tube and a top plate. Because of the period elongation due to the isolation layer and the limited amount of force transferred by the relatively flexible connector rod, bridge columns are protected from experiencing damage, thus leading to improved seismic behavior. The V-connector system also facilitates the ABC by allowing on-site assembly of prefabricated structural parts including those of the V-connector. A single-column, two-span highway bridge located in Northern California was used for the proof-of-concept of the proposed V-connector protective system. The V-connector was designed to result in an elastic bridge response based on nonlinear dynamic analyses of the bridge model with the V-connector. Accordingly, a one-third scale V-connector was fabricated based on a set of selected design parameters. A quasi-static cyclic test was first conducted to characterize the force-displacement relationship of the V-connector, followed by a hybrid simulation (HS) test in the longitudinal direction of the bridge to verify the intended linear elastic response of the bridge system. In the HS test, all bridge components were analytically modeled except for the V-connector, which was simulated as the experimental substructure in a specially designed and constructed test setup. Linear elastic bridge response was confirmed according to the HS results. The response of the bridge with the V-connector was compared against that of the as-built bridge without the V-connector, which experienced significant column damage. These results justified the effectiveness of this innovative device. The second part of the study presents the HS test conducted on a one-third scale two-column bridge bent with self-centering columns (broadly defined as “resilient columns” in this study) to reduce (or ultimately eliminate) any residual drifts. The comparison of the HS test with a previously conducted shaking table test on an identical bridge bent is one of the highlights of this study. The concept of resiliency was incorporated in the design of the bridge bent columns characterized by a well-balanced combination of self-centering, rocking, and energy-dissipating mechanisms. This combination is expected to lead to minimum damage and low levels of residual drifts. The ABC is achieved by utilizing precast columns and end members (cap beam and foundation) through an innovative socket connection. In order to conduct the HS test, a new hybrid simulation system (HSS) was developed, utilizing commonly available software and hardware components in most structural laboratories including: a computational platform using Matlab/Simulink [MathWorks 2015], an interface hardware/software platform dSPACE [2017], and MTS controllers and data acquisition (DAQ) system for the utilized actuators and sensors. Proper operation of the HSS was verified using a trial run without the test specimen before the actual HS test. In the conducted HS test, the two-column bridge bent was simulated as the experimental substructure while modeling the horizontal and vertical inertia masses and corresponding mass proportional damping in the computer. The same ground motions from the shaking table test, consisting of one horizontal component and the vertical component, were applied as input excitations to the equations of motion in the HS. Good matching was obtained between the shaking table and the HS test results, demonstrating the appropriateness of the defined governing equations of motion and the employed damping model, in addition to the reliability of the developed HSS with minimum simulation errors. The small residual drifts and the minimum level of structural damage at large peak drift levels demonstrated the superior seismic response of the innovative design of the bridge bent with self-centering columns. The reliability of the developed HS approach motivated performing a follow-up HS study focusing on the transverse direction of the bridge, where the entire two-span bridge deck and its abutments represented the computational substructure, while the two-column bridge bent was the physical substructure. This investigation was effective in shedding light on the system-level performance of the entire bridge system that incorporated innovative bridge bent design beyond what can be achieved via shaking table tests, which are usually limited by large-scale bridge system testing capacities.
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Lafrancois, Toben, Mark Hove et Jay Glase. Zebra mussel (Dreissena polymorpha) distribution in Apostle Islands National Lakeshore : SCUBA-based search and removal efforts : 2019–2020. National Park Service, mai 2022. http://dx.doi.org/10.36967/nrr-2293376.

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Invasive zebra mussels (Dreissena polymorpha) were first observed in situ at Apostle Islands National Lakeshore (APIS) in 2015. This report builds on 2018 SCUBA surveys and Environmental Protection Agency (EPA) veliger sampling to: 1) determine whether shoals on APIS borders act as sentinel sites to corroborate veliger drift hypotheses about invasion pathways, 2) evaluate ongoing hand-removal of zebra mussels from easily identified structures, and 3) continue efforts to assess native unionid mussel populations, particularly where zebra mussels are also present. Standard catch per unit effort survey methods by SCUBA teams were used to determine the distribution and relative abundance of zebra or quagga mussels (dreissenids) and native mussels (unionids). Zebra mussels were present at densities between 3 and 42 n/diver/hr (number of mussels per diver per hour), while native unionids were present at densities between 5 and 72 n/diver/hr. Shoal surveys (Eagle Island shoal, Sand Island shoal, York Island shoal, Bear Island shoal, Oak Island shoal, and Gull Island shoal) showed zebra mussels were more abundant on the west side of APIS and absent on the easternmost shoal (Gull Island), corroborating veliger work by the EPA that suggested drift from the Twin Ports of Duluth, Minnesota, and Superior, Wisconsin, is one pathway of invasion. Our results support the use of shallow shoals along the periphery of the park as sentinel sites gauging zebra mussel immigration and population dynamics. Zebra mussel densities in the central islands showed no obvious spatial pattern, and this survey cannot determine whether currents or human transport (or both) are invasion vectors. Given the mussels’ continued presence at heavily used mooring areas and docks where there are no zebra mussels on nearby natural features (e.g., Rocky Island dock, Stockton Island mooring areas), our findings are consistent with multiple invasion pathways (drift from the Twin Ports and anthropogenic sources at mooring areas). SCUBA search and removal of zebra mussels from docks was confirmed to be an effective method for significantly lowering the risk of zebra mussels reproducing and dispersing from these locations. We caution that this work is being done on what look like initial invasions at low densities. Repeated removal of zebra mussels by divers reduced numbers to zero at some sites after one year (South Twin docks, Stockton Island NPS docks, and the Ottawa wreck) or decreased numbers by an order of magnitude (Rocky Island docks). Dreissenid densities were more persistent on the Sevona wreck and longer-term work is required to evaluate removal versus recruitment (local and/or veliger drift). Given the size of the wreck, we have tracked detailed survey maps to guide future efforts. Zebra mussels were again observed attached to native mussels near Stockton Island and South Twin Island. Their continued presence on sensitive native species is of concern. Native unionid mussels were more widely distributed in the park than previously known, with new beds found near Oak and Basswood Islands. The work reported here will form the basis for continued efforts to determine the optimal frequency of zebra mussel removal for effective control, as well as evaluate impacts on native species.
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Monetary Policy Report - July de 2021. Banco de la República, octobre 2021. http://dx.doi.org/10.32468/inf-pol-mont-eng.tr3-2021.

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Macroeconomic summary The Colombian economy sustained numerous shocks in the second quarter, pri¬marily related to costs and supply. The majority of these shocks were unantic¬ipated or proved more persistent than expected, interrupting the recovery in economic activity observed at the beginning of the year and pushing overall inflation above the target. Core inflation (excluding food and regulated items) increased but remained low, in line with the technical staff’s expectations. A third wave of the pandemic, which became more severe and prolonged than the previous outbreak, began in early April. This had both a high cost in terms of human life and a negative impact on Colombia's economic recovery. Between May and mid-June roadblocks and other disruptions to public order had a sig¬nificant negative effect on economic activity and inflation. The combination and magnitude of these two shocks likely led to a decline in gross domestic product (GDP) compared to the first quarter. Roadblocks also led to a significant in¬crease in food prices. The accumulated effects of global disruptions to certain value chains and increased international freight transportation prices, which since the end of 2020 have restricted supply and increased costs, also affected Colombia’s economy. The factors described above, which primarily affected the consumer price index (CPI) for goods and foods, explain to a significant degree the technical staff’s forecast errors and the increase in overall inflation above the 3% target. By contrast, increases in core inflation and in prices for regulated items were in line with the technical staff’s expectations, and can be explained largely by the elimination of various price relief measures put in place last year. An increase in perceived sovereign risk and the upward pressures that this im¬plies on international financing costs and the exchange rate were further con¬siderations. Despite significant negative shocks, economic growth in the first half of the year (9.1%) is now expected to be significantly higher than projected in the April re¬port (7.1%), a sign of a more dynamic economy that could recover more quickly than previously forecast. Diverse economic activity figures have indicated high¬er-than-expected growth since the end of 2020. This suggests that the negative effects on output from recurring waves of COVID-19 have grown weaker and less long-lasting with subsequent outbreaks. Nevertheless, the third wave of the coro¬navirus, and to an even greater degree the previously mentioned roadblocks and disruptions to public order, likely led to a decline in GDP in the second quar¬ter compared to the first. Despite this, data from the monthly economic tracking indicator (ISE) for April and May surpassed expectations, and new sector-level measures of economic activity suggest that the negative impact of the pandemic on output continues to moderate, amid reduced restrictions on mobility and im¬provements in the pace of vaccination programs. Freight transportation registers (June) and unregulated energy demand (July), among other indicators, suggest a significant recovery following the roadblocks in May. Given the above, annual GDP growth in the second quarter is expected to have been around 17.3% (previously 15.8%), explained in large part by a low basis of comparison. The technical staff revised its growth projection for 2021 upward from 6% to 7.5%. This forecast, which comes with an unusually high degree of uncertain¬ty, assumes no additional disruptions to public order and that any new waves of COVID-19 will not have significant additional negative effects on economic activity. Recovery in international demand, price levels for some of Colombia’s export com¬modities, and remittances from workers abroad have all performed better than projected in the previous report. This dynamic is expected to continue to drive recovery in the national income over the rest of the year. Continued ample international liquidity, an acceleration in vacci¬nation programs, and low interest rates can also be ex¬pected to favor economic activity. Improved performance in the second quarter, which led to an upward growth revision for all components of spending, is expected to continue, with the economy returning to 2019 production levels at the end of 2021, earlier than estimated in the April report. This forecast continues to account for the short-term effects on aggregate demand of a tax reform package along the lines of what is currently being pro-posed by the national government. Given the above, the central forecast scenario in this report projects growth in 2021 of 7.5% and in 2022 of 3.1% (Graph 1.1). In this scenar¬io, economic activity would nonetheless remain below potential. The noted improvement in these projections comes with a high degree of uncertainty. Annual inflation increased more than expected in June (3.63%) as a result of changes in food prices, while growth in core inflation (1.87%) was similar to projections.
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