Time, by definition, is an intangible phenomenon. Everyone knows it exists and can tell the passage of time based on the track of the sun and the hands on a clock, but time itself is an invisible entity. This architectural thesis maintains that time can be made tangible through the relationships formed between people and their personal histories and memories. The predominant way the present knows anything about its past is through someone's telling of it. A person who experienced the past shares with the present and in doing so, gives the past and time itself presence. This Memory Center, located in Dupont Circle, Washington, D.C., gives the opportunity for people to share their memories and experiences in order to give time physical presence. Like an interactive science museum, the Memory Center opens itself to the people who visit it and allows for interactions that create lasting memories. Although one cannot consciously control most of what becomes memory, events that are new or unusual or involve interacting with new people usually form stronger and more lasting memories. / Master of Architecture

The solution of initial value problems is a fundamental component of many scientific simulations of physical phenomena. In many cases these initial value problems arise from a method of lines approach to solving partial differential equations, resulting in very large systems of equations that require the use of numerical time integration methods to solve. Many problems of scientific interest exhibit stiff behavior for which implicit methods are favorable, however standard implicit methods are computationally expensive. They require the solution of one or more large nonlinear systems at each timestep, which can be impractical to solve exactly and can behave poorly when solved approximately. The recently introduced ``lightly-implicit'' K-methods seek to avoid this issue by directly coupling the time integration methods with a Krylov based approximation of linear system solutions, treating a portion of the problem implicitly and the remainder explicitly. This work seeks to further two primary objectives: evaluation of these K-methods in large-scale parallel applications, and development of new linearly implicit methods for contexts where improvements can be made. To this end, Rosenbrock-Krylov methods, the first K-methods, are examined in a scalability study, and two new families of time integration methods are introduced: biorthogonal Rosenbrock-Krylov methods, and linearly implicit multistep methods. For the scalability evaluation of Rosenbrock-Krylov methods, two parallel contexts are considered: a GPU accelerated model and a distributed MPI parallel model. In both cases, the most significant performance bottleneck is the need for many vector dot products, which require costly parallel reduce operations. Biorthogonal Rosenbrock-Krylov methods are an extension of the original Rosenbrock-Krylov methods which replace the Arnoldi iteration used to produce the Krylov approximation with Lanczos biorthogonalization, which requires fewer vector dot products, leading to lower overall cost for stiff problems. Linearly implicit multistep methods are a new family of implicit multistep methods that require only a single linear solve per timestep; the family includes W- and K-method variants, which admit arbitrary or Krylov based approximations of the problem Jacobian while maintaining the order of accuracy. This property allows for a wide range of implementation optimizations. Finally, all the new methods proposed herein are implemented efficiently in the MATLODE package, a Matlab ODE solver and sensitivity analysis toolbox, to make them available to the community at large. / Doctor of Philosophy / Differential equations are a fundamental building block of the mathematical description of many physical phenomena. Thus, solving problems involving complex differential equations is necessary for construction of scientific models of these phenomena, which can then be used to make useful predictions, such as weather forecasts. Aside from some simplified cases, complex differential equations cannot be solved exactly. Time integration methods are a class of numerical algorithms used to compute approximate solutions to differential equations, by stepping a given initial solution forward in time, producing a new solution at each timestep. Time integration methods are generally categorized as either explicit or implicit methods. Explicit methods are simpler, but have significant restrictions on the size of timesteps for challenging differential equations. Implicit methods relax this timestep restriction, but are much more expensive to compute. The recently introduced ``lightly-implicit'' K-methods provide a way to fuse the advantages of both implicit and explicit methods, by effectively treating a portion of the problem implicitly and the remainder explicitly. This work seeks to further two primary objectives: evaluation of these K-methods on very large problems, and development of new time integration methods. To this end, Rosenbrock--Krylov methods, the first K-methods, are applied to a large-scale problem and examined in a scalability study, and two new families of time integration methods are introduced: biorthogonal Rosenbrock--Krylov methods, and linearly implicit multistep methods. Ultimately, the goal is to develop new methods which allow for the creation of larger, more detailed, and more accurate scientific models, in order to get better and faster predictions.

There never comes a point at which we can declare any building "finished", and never touch it again; if we were to do this it would signal a sad sort of death and the end of the building's use, because it is by a continual process of revision that they fulfill our ever-changing needs and tastes. However, acknowledging this dynamic aspect of the nature of buildings brings the role of the architect into question; how can we design a building, make drawings and reach practical completion on a building site whilst being aware of the looming future, with its eternal punch list of alterations? Or, how can an awareness of passing time as a gradual tweaker, weatherer, and alterer of buildings be seen not as a problem or annoyance for the architect, but as a generous and reliable source of inspiration, a giver of richness, even a generator of good design? The project aims to answer this question by suggesting a way of building slowly, over decades, always looking forward and back. / Master of Architecture

Rae Langton's interpretation of the distinction between things in themselves and phenomena solves many traditional problems at the expense of Kant's discussion of the categories and time, which she thinks are irrelevant to explaining the problem of affection. Langton applies the concept "substance" in a transcendentally real manner to things in themselves, in order to argue that we are ignorant of the latter because they are causally inert intrinsic properties. In doing so, she misdiagnoses the source of Humility, which can be properly understood by the fact that things in themselves are not objects of experience. Langton misapplies the concept of substance to things in themselves, and says that substance of the First Analogy is phaenomenon substantiatum. I argue that substance is a concept which should only be applied to matter in order to unite perceptions in an objective time order. / Master of Arts

The research presented in this thesis represents an effort to characterize the properties of ultra-high molecular weight polyethylene (UHMWPE). As a composite of polymers, the properties of UHMWPE are time-dependent. It is desired by research sponsors to know the properties of the material at high strain rates, in order to simulate the use of these materials in computer models. Properties believed to be significant which are investigated in this research are the tensile properties of lamina and laminates, and the interlaminar shear properties of laminates. The efficacy of using time-temperature superposition to shift tensile properties of the composite is investigated, and a novel apparent shear strength test is proposed and demonstrated. The effects of processing the material at various temperatures and pressures are also investigated. / Master of Science

Life is a series of moments. Architecture is experienced by a series of moments. Prison is experienced by a series of measured moments. / Master of Architecture

International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper describes a real-time implementation of the pattern recognition technology originally developed by BBN [Delatizky et al] for post-processing of time-sampled telemetry data. This makes it possible to monitor a data stream for a characteristic shape, such as an arrhythmic heartbeat or a step-response whose overshoot is unacceptably large. Once programmed to recognize patterns of interest, it generates a symbolic description of a time-series signal in intuitive, object-oriented terms. The basic technique is to decompose the signal into a hierarchy of simpler components using rules of grammar, analogous to the process of decomposing a sentence into phrases and words. This paper describes the basic technique used for pattern recognition of time-series signals and the problems that must be solved to apply the techniques in real time. We present experimental results for an unoptimized prototype demonstrating that 4000 samples per second can be handled easily on conventional hardware.

This thesis describes and defends the moving spotlight theory, a metaphysical theory concerning the fundamental temporal structure of reality. The moving spotlight theory has two essential components: first, a thesis about presentness; and second, a thesis about the existence (in the most general sense) of things over time. The first thesis is that exactly one instant of time is absolutely, objectively, non-relatively present. This thesis is usually called the ‘A-theory of time’. (The opposing view, according to which no instant of time is absolutely, objectively, non-relatively present, is usually called the ‘B-theory of time’.) The second thesis is that things neither begin nor cease to exist over time; in other words, that it is always the case that everything exists forever. Following Williamson (2013), I call this thesis permanentism. Historically, the moving spotlight theory has been among the least popular plausible theories of time. However, that is because the view has been badly misconstrued. In this thesis I provide a careful description of the moving spotlight theory and show that moving spotlighters can easily respond to the main arguments that have been raised against their view. I also show that the moving spotlight theory, when correctly understood, is the very best theory of time. In particular, the moving spotlight theory inherits the simplicity, explanatory power, and scientific respectability of permanentism, while at the same time describing a world in which there is genuine time and change. In terms of structure, the thesis has two parts, each containing three chapters. In Chapter One, I introduce the A-theory and defend it against some common objections. In Chapter Two, I describe a version of the moving spotlight theory which I call ‘classic MST’, and argue that if the moving spotlight theory is true, classic MST is true. In Chapter Three, I argue against the traditional method of characterising theories of time, and develop a new method in its place. In Chapter Four, I argue that the A-theory is true. In Chapters Five and Six, I argue that we think and speak as if permanentism is true, so we should accept permanentism. I conclude that the moving spotlight theory, and therefore classic MST, is true.

International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / In this paper we present the REAL/STONE Real-Time Tester, a tool for performance evaluation of real-time UNIX operating systems. The REAL/STONE Real-Time Tester is a synthetic benchmark that simulates a typical real-time environment. The tool performs typical real-time operations, such as: (a) reads data from an external source and accesses it periodically, (b) processes data through a number of real-time processes, and © displays the final data. This study can help users in selecting the most-effective real-time UNIX operating system for a given application.

Distortions in the perception of time historically have been associated with dissociation and psychosis in clinical populations. However, the relations among dissociation, psychosis, and time perception in sub-clinical populations have not been investigated. In the present study, college undergraduates scoring either normally or deviantly high on the Per-Mag were given a Dissociative Experiences Scale (DES) and a computerized time-estimation/production task. Participants scoring high on the Per-Mag obtained higher scores on the DES than participants scoring low on the Per- Mag. Per-Mag scores also correlated positively with DES scores across 608 total participants screened. The relation between dissociative and psychotic symptomatology is discussed considering dichotomous versus continuous conceptualizations of psychopathology. The effects of intelligence, social desirability, malingering, gender, and post-traumatic stress on the measures used are also discussed.