826 research outputs found
Ultra-high-frequency piecewise-linear chaos using delayed feedback loops
We report on an ultra-high-frequency (> 1 GHz), piecewise-linear chaotic
system designed from low-cost, commercially available electronic components.
The system is composed of two electronic time-delayed feedback loops: A primary
analog loop with a variable gain that produces multi-mode oscillations centered
around 2 GHz and a secondary loop that switches the variable gain between two
different values by means of a digital-like signal. We demonstrate
experimentally and numerically that such an approach allows for the
simultaneous generation of analog and digital chaos, where the digital chaos
can be used to partition the system's attractor, forming the foundation for a
symbolic dynamics with potential applications in noise-resilient communications
and radar
Rotor design optimization using a free wake analysis
The aim of this effort was to develop a comprehensive performance optimization capability for tiltrotor and helicopter blades. The analysis incorporates the validated EHPIC (Evaluation of Hover Performance using Influence Coefficients) model of helicopter rotor aerodynamics within a general linear/quadratic programming algorithm that allows optimization using a variety of objective functions involving the performance. The resulting computer code, EHPIC/HERO (HElicopter Rotor Optimization), improves upon several features of the previous EHPIC performance model and allows optimization utilizing a wide spectrum of design variables, including twist, chord, anhedral, and sweep. The new analysis supports optimization of a variety of objective functions, including weighted measures of rotor thrust, power, and propulsive efficiency. The fundamental strength of the approach is that an efficient search for improved versions of the baseline design can be carried out while retaining the demonstrated accuracy inherent in the EHPIC free wake/vortex lattice performance analysis. Sample problems are described that demonstrate the success of this approach for several representative rotor configurations in hover and axial flight. Features that were introduced to convert earlier demonstration versions of this analysis into a generally applicable tool for researchers and designers is also discussed
Computation of rotor aerodynamic loads in forward flight using a full-span free wake analysis
The development of an advanced computational analysis of unsteady aerodynamic loads on isolated helicopter rotors in forward flight is described. The primary technical focus of the development was the implementation of a freely distorting filamentary wake model composed of curved vortex elements laid out along contours of constant vortex sheet strength in the wake. This model captures the wake generated by the full span of each rotor blade and makes possible a unified treatment of the shed and trailed vorticity in the wake. This wake model was coupled to a modal analysis of the rotor blade dynamics and a vortex lattice treatment of the aerodynamic loads to produce a comprehensive model for rotor performance and air loads in forward flight dubbed RotorCRAFT (Computation of Rotor Aerodynamics in Forward Flight). The technical background on the major components of this analysis are discussed and the correlation of predictions of performance, trim, and unsteady air loads with experimental data from several representative rotor configurations is examined. The primary conclusions of this study are that the RotorCRAFT analysis correlates well with measured loads on a variety of configurations and that application of the full span free wake model is required to capture several important features of the vibratory loading on rotor blades in forward flight
Revealing Character Personality Traits In Short Films
The thesis focuses on the research of personality traits in characters portrayed in short
films. The characters and their very own vibrant personalities are the backbone of each
story thus their personalities play a huge role in shaping the plot of the story. The
problem statement given is the limitation in terms of function (form) in short films,
limits the tools given to shape character personality traits. Duration in short films are a
limiting factor when creating in depth characters compared to feature length films. The
objective of this research is to research about the techniques readily available to reveal
personality traits of characters in short films. Thus several data collection techniques are
used in this thesis in forms of interviews, script analysis, literature analysis and film
analysis in terms of structure and character development. The interviewees are Mr.
Hassan Abd. Muthalib and Mr. Bernard Chauly respectively. The type of analysis used
is from qualitative methods and carried out using case study and content analysis. For
the findings of this research, a diagram using the data available has been constructed
using the act structure to display the end results of this research. The findings reveal the
two key elements (turning points, core morality values) which are the main essentials to
creating in depth characters within a short duration of time
Majorana zero modes and their bosonization
The simplest continuum model of a one-dimensional non-interacting
superconducting fermionic symmetry-protected topological (SPT) phase is studied
in great detail using analytical methods. In a first step, we present a full
exact diagonalization of the fermionic Bogoliubov-de Gennes Hamiltonian for a
system of finite length and with open boundaries. In particular, we derive
exact analytical expressions for the Majorana zero modes emerging in the
topologically non-trivial phase, revealing their spatial localization, their
transformation properties under symmetry operations, and the exact finite-size
energy splitting of the associated quasi-degenerate ground states. We then
proceed to analyze the model via exact operator bosonization in both open and
closed geometries. In the closed wire geometry, we demonstrate fermion parity
switching from twisting boundary conditions in the topologically non-trivial
phase. For the open wire, on the other hand, we first take a semiclassical
approach employing the Mathieu equation to study the two quasi-degenerate
ground states as well as their energy splitting at finite system sizes. We then
finally derive the exact forms of the Majorana zero modes in the bosonic
language using vertex-algebra techniques. These modes are verified to be in
exact agreement with the results obtained from the fermionic description. The
complementary viewpoints provided by the fermionic and bosonic formulations of
the superconducting SPT phase are reconciled, allowing us to provide a complete
and exact account of how Majorana zero modes manifest in a bosonized
description of an SPT phase
Concert recording 2017-05-17
[Track 1]. Second line / Traditional -- [Track 2]. When the saints go marching in : gospel hymn -- [Track 3]. A tisket, a tasket / arranged by Ella Fitzgerald -- [Track 4]. Joshua : African American spiritua
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Neural Correlates of Metamemory: A Comparison of Feeling-of-Knowing and Retrospective Confidence Judgments
Metamemory refers to knowledge and monitoring of one's own memory. Metamemory monitoring can be done prospectively with respect to subsequent memory retrieval or retrospectively with respect to previous memory retrieval. In this study, we used fMRI to compare neural activity during prospective feeling-of-knowing and retrospective confidence tasks in order to examine common and distinct mechanisms supporting multiple forms of metamemory monitoring. Both metamemory tasks, compared to non-metamemory tasks, were associated with greater activity in medial prefrontal, medial parietal, and lateral parietal regions, which have previously been implicated in internally directed cognition. Furthermore, compared to non-metamemory tasks, metamemory tasks were associated with less activity in occipital regions, and in lateral inferior frontal and dorsal medial prefrontal regions, which have previously shown involvement in visual processing and stimulus-oriented attention, respectively. Thus, neural activity related to metamemory is characterized by both a shift toward internally directed cognition and away from externally directed cognition. Several regions demonstrated differences in neural activity between feeling-of-knowing and confidence tasks, including fusiform, medial temporal lobe, and medial parietal regions; furthermore, these regions also showed interaction effects between task and the subjective metamemory rating, suggesting that they are sensitive to the information monitored in each particular task. These findings demonstrate both common and distinct neural mechanisms supporting metamemory processes and also serve to elucidate the functional roles of previously characterized brain networks.Psycholog
Update on Anti-EGFR Therapy
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The Filipino Nation and its Fabrication: From a Catholic Perspective
This is a synthesis between Filipino History, Thomistic Philosophy, and Catholic Social Teaching. This work seeks to examine (i) the history of Filipino nation building; (ii) Catholic views on nationhood in this particular context, (iii) the ideological aspects of Filipino nationalism, (iv) the situation of the local Catholic Church, (v) Catholic social doctrine and its particular application
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