373 research outputs found
My Plan to Play: A Personal Journey towards a Lifetime of Play
In my first Critical and Creative Thinking course, I chose to explore singing and performing meaningful songs with my father as a form of creative thinking. This project led to the realization that, as an adult, I had forgotten what it was like to play. With this acknowledgement, I was prompted to explore underlying reasons for why my capacity to play was blocked in the first place. In doing so, I explored play theories and reflected on my own forms of play, as a basis for understanding how to successfully re-introduce play into my life. Through metacognitive reflection, this synthesis describes the journey to recapturing my creatively playful self - from the point of recognizing its loss, to identifying significant underlying blocks, to devising and applying effective strategies for removing them. Before my reflective journey could proceed, it was important to explore the complex meaning of play and its importance to both children and adults. Despite the many definitions and theories of play by Brannen, Csikszentmihalyi, Vygotsky, and others, I decided that to create a lifelong practice of play, I first would need to establish my own conception of creative play: one that involves an expression of music, dance, writing, and a reconnection with my childhood play. Next, I explored the importance of play, especially unstructured play in children, and its benefits. I discovered that there seems to be no reason why these same benefits, including increased intellectual, social, physical, and emotional capabilities, could not apply to adults as well. After this process of examination, I made a plan to actively play again through music, dance, writing, and my work as a communications professional, through a series of specific projects. Through weekly written reflections on playful projects, I describe the journey to rediscovering my ability to play. In my project, I explore how each of these experiences helped me to be myself again and overcome significant creative blocks, such as fear of failure, fear of being judged, and negative self-talk. In reconnecting with my own kind of creative play, new ways to keep it alive are discovered that will enrich my life beyond the Critical and Creative Thinking program. In addition, I hope to inspire others to find ways to reconnect with their own forms of play
Studies Towards the Synthesis of [10]-Annulenes
This thesis begins with a historical perspective on aromaticity and benzene, including the discovery and proposed structures for benzene as well as proposed criteria for measuring aromaticity. The history of the synthesis and characterization of [10]-annulene is also discussed.
Studies towards the synthesis of an aromatic all-cis-[10]-annulene derivative is covered in this dissertation. Two routes that were explored in efforts to obtain a chlorinated all-cis-[10]-annulene derivative, 40, are described. The primary route utilizes six chlorine atoms on the hydrocarbon skeleton (R=H) and uses a carbene [2+1] cycloaddition reaction as a key step to incorporate one of the two cyclopropane substituents (Scheme 1.0). The second cyclopropane unit is incorporated through a Diels-Alder reaction between diene 49 and tetrachlorocyclopropene 50, which also established the 10-carbon framework. The cleavage of the central olefin in the 10-carbon skeleton 51 is discussed, as well as difficulties encountered. In attempts to obtain the planar, aromatic [10]-annulene, efforts towards the elimination and oxidation reactions which lead to the aromatization of 55 are also presented.
This thesis also discusses an alternative route that incorporates an additional chlorine atom on the carbon framework (R=Cl). The alternative route mirrors the previous pathway; one cyclopropane substituent is incorporated through a carbene [2+1] cycloaddition reaction, whereas the second unit is established via a Diels-Alder reaction (Scheme 1.0). Efforts towards cleaving the olefin in 51 to obtain the carbon skeleton 40 are also discussed.
This work concludes with a general discussion and proposal for future directions, with an emphasis on alternative synthetic pathways. This study demonstrates the Diels-Alder reactions and ozonolysis of 51 is a viable strategy to form the functionalized skeleton required for [10]-annulene derivative 40
Generation linewidth of an auto-oscillator with a nonlinear frequency shift: Spin-torque nano-oscillator
It is shown that the generation linewidth of an auto-oscillator with a
nonlinear frequency shift (i.e. an auto-oscillator in which frequency depends
on the oscillation amplitude) is substantially larger than the linewidth of a
conventional quasi-linear auto-oscillator due to the renormalization of the
phase noise caused by the nonlinearity of the oscillation frequency. The
developed theory, when applied to a spin-torque nano-contact auto-oscillator,
predicts a minimum of the generation linewidth when the nano-contact is
magnetized at a critical angle to its plane, corresponding to the minimum
nonlinear frequency shift, in good agreement with recent experiments.Comment: 4 pages, 2 figure
Lineshape distortion in a nonlinear auto-oscillator near generation threshold: Application to spin-torque nano-oscillators
The lineshape in an auto-oscillator with a large nonlinear frequency shift in
the presence of thermal noise is calculated. Near the generation threshold,
this lineshape becomes strongly non-Lorentzian, broadened, and asymmetric. A
Lorentzian lineshape is recovered far below and far above threshold, which
suggests that lineshape distortions provide a signature of the generation
threshold. The theory developed adequately describes the observed behavior of a
strongly nonlinear spin-torque nano-oscillator.Comment: 4 pages, 3 figure
02/17/1947 Letter from Le Petit Septuor de la Bonne Chanson
Letter from Arthur Blaquiere of Le Petit Septuor de la Bonne Chanson to Louis-Philippe Gagné.https://digitalcommons.usm.maine.edu/fac-lpg-1947-01-03/1002/thumbnail.jp
Oscillatory transient regime in the forced dynamics of a spin torque nano-oscillator
We demonstrate that the transient non-autonomous dynamics of a spin torque
nano-oscillator (STNO) under a radio-frequency (rf) driving signal is
qualitatively different from the dynamics described by the Adler model. If the
external rf current is larger than a certain critical value
(determined by the STNO bias current and damping) strong oscillations of the
STNO power and phase develop in the transient regime. The frequency of these
oscillations increases with as and can
reach several GHz, whereas the damping rate of the oscillations is almost
independent of . This oscillatory transient dynamics is caused by the
strong STNO nonlinearity and should be taken into account in most STNO rf
applications.Comment: 4 page, 3 figure
Evaluation of Anisotropic Conductive Films Based on Vertical Fibers for Post-CMOS Wafer-Level Packaging
In this paper, we investigate the mechanical and electrical properties of an anisotropic conductive film (ACF) on the basis of high-density vertical fibers for a wafer-level packaging (WLP) application. As part of the WaferBoard, a\ud
reconfigurable circuit platform for rapid system prototyping,\ud
ACF is used as an intermediate film providing compliant and\ud
vertical electrical connection between chip contacts and a top surface of an active wafer-size large-area IC. The chosen ACF is first tested by an indentation technique. The results show that the elastic–plastic deformation mode as well as the Young’s modulus and the hardness depend on the indentation depth. Second, the efficiency of the electrical contact is tested using a uniaxial compression on a stack comprising a dummy ball grid array (BGA) board, an ACF, and a thin Al film. For three bump diameters, as the compression increases, the resistance values decrease before reaching low and stable values. Despite the BGA solder bumps exhibit plastic deformation after compression, no damage is found on the ACF film. These results show that vertical fiber ACFs can be used for nonpermanent bonding in a WLP application
Analytic Controllability of Time-Dependent Quantum Control Systems
The question of controllability is investigated for a quantum control system
in which the Hamiltonian operator components carry explicit time dependence
which is not under the control of an external agent. We consider the general
situation in which the state moves in an infinite-dimensional Hilbert space, a
drift term is present, and the operators driving the state evolution may be
unbounded. However, considerations are restricted by the assumption that there
exists an analytic domain, dense in the state space, on which solutions of the
controlled Schrodinger equation may be expressed globally in exponential form.
The issue of controllability then naturally focuses on the ability to steer the
quantum state on a finite-dimensional submanifold of the unit sphere in Hilbert
space -- and thus on analytic controllability. A relatively straightforward
strategy allows the extension of Lie-algebraic conditions for strong analytic
controllability derived earlier for the simpler, time-independent system in
which the drift Hamiltonian and the interaction Hamiltonia have no intrinsic
time dependence. Enlarging the state space by one dimension corresponding to
the time variable, we construct an augmented control system that can be treated
as time-independent. Methods developed by Kunita can then be implemented to
establish controllability conditions for the one-dimension-reduced system
defined by the original time-dependent Schrodinger control problem. The
applicability of the resulting theorem is illustrated with selected examples.Comment: 13 page
In-FPGA instrumentation framework for openCL-based designs
ABSTRACT: The productivity achieved when developing applications on high-performance reconfigurable heterogeneous computing (HPRHC) systems is increased by using the Open Computing Language (OpenCL). However, the hardware produced by OpenCL compilers in field-programmable gate arrays (FPGAs) can result in severe performance bottlenecks that are challenging to solve. The problem is compounded by the fact that the generated netlist details are disorganized, making them mostly unreadable and only partially visible to designers. This paper proposes an in-FPGA instrumentation method and a new framework for extracting the FPGA-cycle-accurate timing performances of OpenCL-based designs. The results clearly show that the chosen execution model for OpenCL-based designs strongly affects the timing performance when it is not properly implemented. Our framework is implemented on an HPRHC platform that contains a CPU and two Arria10 FPGAs, and it is evaluated with a wide variety of benchmarks with different complexities. After testing on the reported benchmarks, the average logic overhead for one inserted instrument is 0.2 % of the total amount of adaptive look-up tables (ALUTs) and 0.1 % of the total registers in an FPGA. This resource utilization is between 1.5 and six times lower than those reported in the best previously published works. The scalability of the framework is also evaluated by inserting up to 50 instruments. The experimental results show that the average logic utilization per instrument is 0.19 % of the ALUTs and 0.17 % of the registers in the FPGA when 50 instruments are inserted
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