25 research outputs found

    Democratic Disobedience

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    Logical relations in Chinese and the theory of grammar

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    Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Linguistics and Philosophy, 1982.MICROFICHE COPY AVAILABLE IN ARCHIVES AND HUMANITIES.Vita.Bibliography: leaves 587-597.by Cheng-Teh James Huang.Ph.D

    An investigation into the relationship between the stability of a biological community and both community complexity and environmental heterogeneity.

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    The aim of this dissertation is to study two aspects of the stability properties of a biological community. These are firstly their relationship with the structural complexity of the community and secondly the effect of spatial heterogeneity of the environment in which the community lives. Chapter 1 introduces the subject of population dynamics and discusses the reasons for using mathematical models to study it . The first part of Chapter 2 defines the terminology, especially the meaning of stability. The second part considers the biological evidence for a relationship between stability and complexity while the third part investigates the stability properties of mathematical models of communities of varying complexities. It is concluded that there is no general relationship, but that the more complex a community the more unlikely it is to be stable. The first part of Chapter 3 discusses the biological evidence for the importance of the effect of spatial heterogeneity on stability and proposes a definition of this term. The second part describes different ways of modelling community population dynamics in spatially heterogeneous environments. It is concluded that spatial heterogeneity is not likely to make a community less stable

    New Foundation in the Sciences: Physics without sweeping infinities under the rug

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    It is widely known among the Frontiers of physics, that “sweeping under the rug” practice has been quite the norm rather than exception. In other words, the leading paradigms have strong tendency to be hailed as the only game in town. For example, renormalization group theory was hailed as cure in order to solve infinity problem in QED theory. For instance, a quote from Richard Feynman goes as follows: “What the three Nobel Prize winners did, in the words of Feynman, was to get rid of the infinities in the calculations. The infinities are still there, but now they can be skirted around . . . We have designed a method for sweeping them under the rug. [1] And Paul Dirac himself also wrote with similar tune: “Hence most physicists are very satisfied with the situation. They say: Quantum electrodynamics is a good theory, and we do not have to worry about it any more. I must say that I am very dissatisfied with the situation, because this so-called good theory does involve neglecting infinities which appear in its equations, neglecting them in an arbitrary way. This is just not sensible mathematics. Sensible mathematics involves neglecting a quantity when it turns out to be small—not neglecting it just because it is infinitely great and you do not want it!”[2] Similarly, dark matter and dark energy were elevated as plausible way to solve the crisis in prevalent Big Bang cosmology. That is why we choose a theme here: New Foundations in the Sciences, in order to emphasize the necessity to introduce a new set of approaches in the Sciences, be it Physics, Cosmology, Consciousness etc

    Conversation in the classroom : investigating the 1999 Stage 6 English syllabus

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    The role of metaphor in user interface design

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    The thesis discusses the question of how unfamiliar computing systems, particularly those with graphical user interfaces, are learned and used. In particular, the approach of basing the design and behaviour of on-screen objects in the system's model world on a coherent theme and employing a metaphor is explored. The drawbacks, as well as the advantages, of this approach are reviewed and presented. The use of metaphors is also contrasted with other forms of users' mental models of interactive systems, and the need to provide a system image from which useful mental models can be developed is presented. Metaphors are placed in the context of users' understanding of interactive systems and novel application is made of the Qualitative Process Theory (QPT) qualitative reasoning model to reason about the behaviour of on-screen objects, the underlying system functionality, and the relationship between the two. This analysis supports reevaluation of the domains between which user interface metaphors are said to form mappings. A novel user interface design, entitled Medusa, that adopts guidelines for the design of metaphor-based systems, and for helping the user develop successful mental models, based on the QPT analysis and an empirical study of a popular metaphor-based system, is described. The first Medusa design is critiqued using well-founded usability inspection method. Employing the Lakoff/Johnson theory, a revised version of the Medusa user interface is described that derives its application semantics and dialogue structures from the entailments of the knowledge structures that ground understanding of the interface metaphor and that capture notions of embodiment in interaction with computing devices that QPT descriptions cannot. Design guidelines from influential existing work, and new methods of reasoning about metaphor-based designs, are presented with a number of novel graphical user interface designs intended to overcome the failings of existing systems and design approaches

    Computational methods and special functions

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    1991 Summer Study Program in Geophysical Fluid Dynamics : patterns in fluid flow

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    The GFD program in 1991 focused on pattern forming processes in physics and geophysics. The pricipallecturer, Stephan Fauve, discussed a variety of systems, including our old favorite, Rayleigh-BĂ©nard convection, but passing on to exotic examples such as vertically vibrated granular layers. Fauve's lectures emphasize a unified theoretical viewpoint based on symmetry arguments. Patterns produced by instabilties can be described by amplitude equations, whose form can be deduced by symmetry arguments, rather than the asymptotic expansions that have been the staple of past Summer GFD Programs. The amplitude equations are far simpler than the complete equations of motion, and symetry arguments are easier than asymptotic expansions. Symmetry arguments also explain why diverse systems are often described by the same amplitude equation. Even for granular layers, where there is not a universaly accepted continuum description, the appropnate amplitude equation can often be found using symmetry arguments and then compared with experiment. Our second speaker, Daniel Rothan, surveyed the state of the art in lattice gas computations. His lectures illustrate the great utility of these methods in simulating the flow of complex multiphase fluids, particularly at low Reynolds numbers. The lattice gas simulations reveal a complicated phenomenology much of which awaits analytic exploration. The fellowship lectures cover broad ground and reflect the interests of the staff members associated with the program. They range from the formation of sand dunes, though the theory of lattice gases, and on to two dimensional-turbulence and convection on planetary scales. Readers desiring to quote from these report should seek the permission of the authors (a partial list of electronic mail addresses is included on page v). As in previous years, these reports are extensively reworked for publication or appear as chapters in doctoral theses. The task of assembling the volume in 1991 was at first faciltated by our newly acquired computers, only to be complicated by hurricane Bob which severed electric power to Walsh Cottage in the final hectic days of the Summer.Funding was provided by the National Science Foundation through Grant No. OCE 8901012

    The Cryptographic Imagination

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    Originally published in 1996. In The Cryptographic Imagination, Shawn Rosenheim uses the writings of Edgar Allan Poe to pose a set of questions pertaining to literary genre, cultural modernity, and technology. Rosenheim argues that Poe's cryptographic writing—his essays on cryptography and the short stories that grew out of them—requires that we rethink the relation of poststructural criticism to Poe's texts and, more generally, reconsider the relation of literature to communication. Cryptography serves not only as a template for the language, character, and themes of much of Poe's late fiction (including his creation, the detective story) but also as a "secret history" of literary modernity itself. "Both postwar fiction and literary criticism," the author writes, "are deeply indebted to the rise of cryptography in World War II." Still more surprising, in Rosenheim's view, Poe is not merely a source for such literary instances of cryptography as the codes in Conan Doyle's "The Dancing-Men" or in Jules Verne, but, through his effect on real cryptographers, Poe's writing influenced the outcome of World War II and the development of the Cold War. However unlikely such ideas sound, The Cryptographic Imagination offers compelling evidence that Poe's cryptographic writing clarifies one important avenue by which the twentieth century called itself into being. "The strength of Rosenheim's work extends to a revisionistic understanding of the entirety of literary history (as a repression of cryptography) and then, in a breathtaking shift of register, interlinks Poe's exercises in cryptography with the hyperreality of the CIA, the Cold War, and the Internet. What enables this extensive range of applications is the stipulated tension Rosenheim discerns in the relationship between the forms of the literary imagination and the condition of its mode of production. Cryptography, in this account, names the technology of literary production—the diacritical relationship between decoding and encoding—that the literary imagination dissimulates as hieroglyphics—the hermeneutic relationship between a sign and its content."—Donald E. Pease, Dartmouth Colleg
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