3,045 research outputs found
Dynamics of quantum adiabatic evolution algorithm for Number Partitioning
We have developed a general technique to study the dynamics of the quantum
adiabatic evolution algorithm applied to random combinatorial optimization
problems in the asymptotic limit of large problem size . We use as an
example the NP-complete Number Partitioning problem and map the algorithm
dynamics to that of an auxilary quantum spin glass system with the slowly
varying Hamiltonian. We use a Green function method to obtain the adiabatic
eigenstates and the minimum excitation gap, ,
corresponding to the exponential complexity of the algorithm for Number
Partitioning. The key element of the analysis is the conditional energy
distribution computed for the set of all spin configurations generated from a
given (ancestor) configuration by simulteneous fipping of a fixed number of
spins. For the problem in question this distribution is shown to depend on the
ancestor spin configuration only via a certain parameter related to the energy
of the configuration. As the result, the algorithm dynamics can be described in
terms of one-dimenssional quantum diffusion in the energy space. This effect
provides a general limitation on the power of a quantum adiabatic computation
in random optimization problems. Analytical results are in agreement with the
numerical simulation of the algorithm.Comment: 32 pages, 5 figures, 3 Appendices; List of additions compare to v.3:
(i) numerical solution of the stationary Schroedinger equation for the
adiabatic eigenstates and eigenvalues; (ii) connection between the scaling
law of the minimum gap with the problem size and the shape of the
coarse-grained distribution of the adiabatic eigenvalues at the
avoided-crossing poin
Stock Market Return and Volatility: Day-of-the-week Effect
Cataloged from PDF version of article.This paper examines the stock market returns and volatility relationship using US daily returns from May 26, 1952 to September 29, 2006. The empirical evidence reported here does not support the proposition that the return-volatility relationship is present and the same for each day of the week. © 2010 Springer Science+Business Media, LLC
CrowdHiLite: A Peer Review Service to Support Serious Reading on the Screen
The advent of smart devices and consumerisation of IT has produced a significant and permanent shift away from print-based reading to digital reading. This, in turn, has changed peopleâs reading behaviours and suggests that adapted mechanisms should be considered to support digital reading. It is particularly important for novice readers who need to read in-depth scientific literature in their chosen field. In this paper, we propose CrowdHiLite, a novel service architecture that allows expert readers to provide suggestion on individual readersâ highlights to support their reading on the screen through the use of crowdsourcing technique. A demonstration was also provided to show how it would work in real world. A preliminary experiment comparing novice readersâ reading performance with expert rated highlights and normal highlights on the same document found improved reading efficiency and comprehension with the former
PV-0173: Dosimetric assessment of three-source Co-60 and Linacbased lung SBRT for feasibility of MR-IGRT
Banking Geography and Cross-Fertilization in the Productivity Growth of US Commercial Banks
The US banking industry offers a unique, natural and fertile environment to study geography's effects on banks' behavior and performance. The literature on banks' operating performance, while extensive, says little about the influence of spatial interactions on banks' performance. We compute and examine, using a physical distance-based spatio-temporal empirical model, the state-wide total factor productivity growth (TFPG) indices of US commercial banks for each state for the 1971-1995 period. We observe that the productivity growth of commercial banks in state i depends strongly, positively, and contemporaneously on the productivity growth of commercial banks located in state i's contiguous states. Further, âregulatory spaceâ appears to induce frictions and lessen the documented spatial interactions. These findings support our plea that research on commercial banking sector's behavior need to pay a particular attention to the effects of banking geography.Spatial, Commercial Banks, Total Factor Productivity Growth, Kalman Filter
Wavelength converter sharing in asynchronous optical packet/burst switching: An exact blocking analysis for markovian arrivals
Cataloged from PDF version of article.In this paper, we study the blocking probabilities
in a wavelength division multiplexing-based asynchronous
bufferless optical packet/burst switch equipped with a bank of
tuneable wavelength converters dedicated to each output fiber
line. Wavelength converter sharing, also referred to as partial
wavelength conversion, corresponds to the case of a number
of converters shared amongst a larger number of wavelength
channels. In this study, we present a probabilistic framework for
exactly calculating the packet blocking probabilities for optical
packet/burst switching systems utilizing wavelength converter
sharing. In our model, packet arrivals at the optical switch are
first assumed to be Poisson and later generalized to the more
general Markovian arrival process to cope with very general
traffic patterns whereas packet lengths are assumed to be exponentially
distributed. As opposed to the existing literature based
on approximations and/or simulations, we formulate the problem
as one of finding the steady-state solution of a continuous-time
Markov chain with a block tridiagonal infinitesimal generator. To
find such solutions, we propose a numerically efficient and stable
algorithm based on block tridiagonal LU factorizations. We show
that exact blocking probabilities can be efficiently calculated
even for very large systems and rare blocking probabilities, e.g.,
systems with 256 wavelengths per fiber and blocking probabilities
in the order of 10â40. Relying on the stability and speed of the
proposed algorithm, we also provide a means of provisioning
wavelength channels and converters in optical packet/burst
switching systems
Investigations of Clinical and Demographical Findings of Children with Positive Stool Specimen with Nonpathogenic Intestinal Parasitic Infections
Detection of Blastocystis sp. Infection using different investigation techniques in children with or without acute diarrhea
Improvement of the Wastewater Biodegradability by Means of Photocatalytic and Wet Oxidation Processes in the Presence of Hydrogen Peroxide
In this study, the effectiveness of photocatalytic oxidation (PO) and wet oxidation (WO) processes as a pre-treatment step on improvement of biodegradability and colour removal of mixture of raw domestic and pre-treated industrial wastewaters, have been
evaluated. More oxygen was obtained by H2O2 (as an oxidant in WO and PO processes) than stoichiometric demand. PO of the wastewater was carried out by illumination of the wastewater with UV lamp (at room temperature, atmospheric pressure, 16.5 h reaction time) and WO of the wastewater was carried out by means of thermal oxidation at autoclave conditions (at 118â120 oC, 1.9â2 bar, 3 h reaction time). 1 g Lâ1 TiO2 in PO process and 0.2 mg Lâ1 Cu++ in WO process were used as catalyst. The results obtained from experiments were not compared with each other due to the difference between the
quality and quantity of the used catalyst and the consumed energy. Colour removal efficiency was 33 % for WO process and 77.6 % for PO process. By applying WO process, 72.7 % increase in the reaction rate coefficient describing the degradability of organic compounds in wastewater was obtained, but this value was 34.5 % in PO process
Human-Centred Design for Intelligent Environments: Preface to the proceedings of the workshop on Human Centred Design for Intelligent Environments.
Preface to the proceedings of the workshop on âHuman Centred Design for Intelligent Environmentsâ organised in conjunction with the 2016 BCS British HCI Conference held at Bournemouth University, July 11th-15th 2016
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