4,926 research outputs found
On the determination of near body orbits using mass concentration models
Mathematical model for near-body orbit calculation using mass concentration, perturbation theory, nonlinear equations, geopotentials, and least squares metho
Inverse problems in partial differential equations
Identification in partial differential equations by Laplace equatio
DELINEATION OF TRACKS OF HEAVY COSMIC RAYS AND NUCLEAR PROCESSES WITHIN LARGE SILVER CHLORIDE CRYSTALS
Delineation of tracks of heavy cosmic rays and nuclear processes with in large silver chloride crystal
Using Quantum Computers for Quantum Simulation
Numerical simulation of quantum systems is crucial to further our
understanding of natural phenomena. Many systems of key interest and
importance, in areas such as superconducting materials and quantum chemistry,
are thought to be described by models which we cannot solve with sufficient
accuracy, neither analytically nor numerically with classical computers. Using
a quantum computer to simulate such quantum systems has been viewed as a key
application of quantum computation from the very beginning of the field in the
1980s. Moreover, useful results beyond the reach of classical computation are
expected to be accessible with fewer than a hundred qubits, making quantum
simulation potentially one of the earliest practical applications of quantum
computers. In this paper we survey the theoretical and experimental development
of quantum simulation using quantum computers, from the first ideas to the
intense research efforts currently underway.Comment: 43 pages, 136 references, review article, v2 major revisions in
response to referee comments, v3 significant revisions, identical to
published version apart from format, ArXiv version has table of contents and
references in alphabetical orde
Universal quantum computation by discontinuous quantum walk
Quantum walks are the quantum-mechanical analog of random walks, in which a
quantum `walker' evolves between initial and final states by traversing the
edges of a graph, either in discrete steps from node to node or via continuous
evolution under the Hamiltonian furnished by the adjacency matrix of the graph.
We present a hybrid scheme for universal quantum computation in which a quantum
walker takes discrete steps of continuous evolution. This `discontinuous'
quantum walk employs perfect quantum state transfer between two nodes of
specific subgraphs chosen to implement a universal gate set, thereby ensuring
unitary evolution without requiring the introduction of an ancillary coin
space. The run time is linear in the number of simulated qubits and gates. The
scheme allows multiple runs of the algorithm to be executed almost
simultaneously by starting walkers one timestep apart.Comment: 7 pages, revte
Searches on star graphs and equivalent oracle problems
We examine a search on a graph among a number of different kinds of objects
(vertices), one of which we want to find. In a standard graph search, all of
the vertices are the same, except for one, the marked vertex, and that is the
one we wish to find. We examine the case in which the unmarked vertices can be
of different types, so the background against which the search is done is not
uniform. We find that the search can still be successful, but the probability
of success is lower than in the uniform background case, and that probability
decreases with the number of types of unmarked vertices. We also show how the
graph searches can be rephrased as equivalent oracle problems
Application of DOT-MORSE coupling to the analysis of three-dimensional SNAP shielding problems
The use of discrete ordinates and Monte Carlo techniques to solve radiation transport problems is discussed. A general discussion of two possible coupling schemes is given for the two methods. The calculation of the reactor radiation scattered from a docked service and command module is used as an example of coupling discrete ordinates (DOT) and Monte Carlo (MORSE) calculations
Serving Exoticism: The Black Female in French Exotic Imagery, 1733-1885
The black female played an important part in the construction of
exotic female sexuality in French painting for nearly two hundred
years, yet her symbolic complexity has not been fully explored. This
thesis is a contextual analysis of the image of the black female in
French painting from the early part of the eighteenth through the
nineteenth century.
Representations of black females in this era are part of the
larger development of turquerie in the eighteenth century and
Orientalism in the nineteenth century. Centered around European
fantasies of Near Eastern and North African harem culture, turquerie
and Orientalism provided an exotic framework in which issues of
female sexuality and its relationship to race was explored. The objects
discussed in this thesis, primarily well known works by academic
painters, are examples of images in which the black female plays a
significant stylistic and ideological role.
The works are examined in relation to literary and scientific
discourses in which ideas about black women were negotiated during
the period. Slavery, imperialism, as well as colonial expansion
contextualize the imagery, and offer tools with which to uncover
encoded meanings inscribed in the exoticized black female.
This analysis provides an expanded definition of the nature of
the black female as a symbol, and outlines a complex, multidimensional
framework in which black female figures operate as a
sexual signifier
Doctor of Philosophy
dissertationWe analyze different models of several chemical reactions. We find that, for some reactions, the steady state behavior of the chemical master equation, which describes the continuous time, discrete state Markov process, is poorly approximated by the deterministic model derived from the law of mass action or a mean field model derived in a similar way. We show that certain simple enzymatic reactions have bimodal stationary distributions in appropriate parameter ranges, though the deterministic and mean field models for these reactions do not have the capacity to admit multiple equilibrium points no matter the choice of rate constants. We provide power series expansions for these bimodal distributions. We also consider several variants of an autocatalytic reaction. This reaction's deterministic model predicts a unique positive stable equilibrium, but the only stationary distribution of its chemical master equation predicts extinction of the autocatalytic chemical species with probability 1. We show that the transient distribution of this chemical master equation is centered near the deterministic equilibrium and that the stationary distribution is only reached on a much longer time scale. Finally, we consider a model for the rotational direction switching of the bacterial rotary motor and propose two possible reductions for the state space of the corresponding Markov chain. One reduction, a mean field approximation, is unable to produce physically realistic phenomena. The other reduction retains the properties of interest in the system while significantly decreasing the computation required for analysis. We use this second reduction to fit parameters for the full stochastic system and suggest a mechanism for the sensitivity of the switch
A reconnaissance space sensing investigation of crustal structure for a strip from the eastern Sierra Nevada to the Colorado Plateau
There are no author-identified significant results in this report. Research progress in applications of ERTS-1 MSS imagery in study of Basin-Range tectonics is summarized. Field reconnaissance of ERTS-1 image anomalies has resulted in recognition of previously unreported fault zones and regional structural control of volcanic and plutonic activity. NIMBUS, Apollo 9, X-15, U-2, and SLAR imagery are discussed with specific applications, and methods of image enhancement and analysis employed in the research are summarized. Areas studied and methods employed in geologic field work are outlined
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