814 research outputs found
Efficient Circuits for Quantum Walks
We present an efficient general method for realizing a quantum walk operator
corresponding to an arbitrary sparse classical random walk. Our approach is
based on Grover and Rudolph's method for preparing coherent versions of
efficiently integrable probability distributions. This method is intended for
use in quantum walk algorithms with polynomial speedups, whose complexity is
usually measured in terms of how many times we have to apply a step of a
quantum walk, compared to the number of necessary classical Markov chain steps.
We consider a finer notion of complexity including the number of elementary
gates it takes to implement each step of the quantum walk with some desired
accuracy. The difference in complexity for various implementation approaches is
that our method scales linearly in the sparsity parameter and
poly-logarithmically with the inverse of the desired precision. The best
previously known general methods either scale quadratically in the sparsity
parameter, or polynomially in the inverse precision. Our approach is especially
relevant for implementing quantum walks corresponding to classical random walks
like those used in the classical algorithms for approximating permanents and
sampling from binary contingency tables. In those algorithms, the sparsity
parameter grows with the problem size, while maintaining high precision is
required.Comment: Modified abstract, clarified conclusion, added application section in
appendix and updated reference
The density and porosity of lunar rocks
Accurate lunar rock densities are necessary for constructing gravity models of the Moon\u27s crust and lithosphere. Most Apollo-era density measurements have errors of 2-5% or more and few include porosity measurements. We report new density and porosity measurements using the bead method and helium pycnometry for 6 Apollo samples and 7 lunar meteorites, with typical grain density uncertainties of 10-30 kg m(-3) (0.3-0.9%) and porosity uncertainties of 1-3%. Comparison between igneous grain densities and normative mineral densities show that these uncertainties are realistic and that the helium fully penetrates the pore space. Basalt grain densities are a strong function of composition, varying over at least 3270 kg m(-3) (high aluminum basalt) to 3460 kg m(-3) (high titanium basalt). Feldspathic highland crust has a bulk density of 22002600 kg m(-3) and porosity of 10-20%. Impact basin ejecta has a bulk density of 2350-2600 kg m(-3) and porosity of similar to 20%
State-of-the-Art of High-Power Gyro-Devices. Update of Experimental Results 2021
This report presents an update of the experimental achievements published in the review “State- of-the-Art of High-Power Gyro-Devices and Free Electron Masers”, Journal of Infrared, Millime-ter, and Terahertz Waves, 41, No. 1, pp 1-140 (2020) related to the development of gyro-devices (Tables 2-34). Emphasis is on high-power gyrotron oscillators for long-pulse or continuous wave (CW) operation and pulsed gyrotrons for any applications
State-of-the-Art of High Power Gyro-Devices and Free Electron Masers. Update 2016 (KIT Scientific Reports ; 7735)
This report reviews the current experimental state-of-the-art of megawatt-class gyrotrons for fusion plasma heating. In addition, it summarizes the status of frequency-tunable gyrotrons, multi-megawatt gyrotrons with coaxial resonator, gyrotrons for technological and spectroscopic applications, relativistic gyrotrons, cyclotron-autoresonance-masers, gyroklystrons, gyro-TWT-and gyrotwystron-amplifiers, gyro-BWOs, gyro-harmonic-convertors gyro-peniotrons, magnicons, and free-electron-masers
Air Force Institute of Technology Research Report 2014
This report summarizes the research activities of the Air Force Institute of Technology’s Graduate School of Engineering and Management. It describes research interests and faculty expertise; lists student theses/dissertations; identifies research sponsors and contributions; and outlines the procedures for contacting the school. Included in the report are: faculty publications, conference presentations, consultations, and funded research projects. Research was conducted in the areas of Aeronautical and Astronautical Engineering, Electrical Engineering and Electro-Optics, Computer Engineering and Computer Science, Systems Engineering and Management, Operational Sciences, Mathematics, Statistics and Engineering Physics
Central Florida Future, Vol. 42 No. 33, May 27, 2010
Waldrop named new provost; Uncover Thursdays; Art Grad; Plus: Wholesome summertime fun; No place for video games at the movies; First SGA meeting reveals vacancies; Professors, students react to oil spill in Gulf;https://stars.library.ucf.edu/centralfloridafuture/3306/thumbnail.jp
State-of-the-Art of High Power Gyro-Devices and Free Electron Masers. Update 2014. (KIT Scientific Reports ; 7693)
Dieser Bericht geht auf den experimentellen Stand von Hochleistungs-Gyrotrons für verschiedene Anwendungen ein. Außerdem wird über frequenzdurchstimmbare Gyrotrons, Multi-MW-Gyrotrons mit koaxialem Resonator, Gyrotrons für technologische und spektroskopische Anwendungen, relativistische Gyrotrons, Zyklotron-Autoresonanz-Maser, Gyroklystrons, Gyro-TWT-und Gyrotwystron-Verstärker, Gyro-RWO, Gyro-Peniotrons, Magnicons, Gyro-Harmonische-Konvertoren u. Frei-Elektronen-Laser berichtet
Central Florida Future, Vol. 41 No. 77, October 1, 2009
Incumbent senator found in violation; Pledge classes put on hold; Uncover Thursdays; I love the \u2780s; Plus: iKiwi: Fro-o, the way to go; Columns: Great American traditions of apathy, steroids; Environment expert advises students on energy, climate; Student said drink was spiked.https://stars.library.ucf.edu/centralfloridafuture/3254/thumbnail.jp
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