3,363 research outputs found
Fast kinetic Monte Carlo simulation of strained heteroepitaxy in three dimensions
Accelerated algorithms for simulating the morphological evolution of strained
heteroeptiaxy based on a ball and spring lattice model in three dimensions are
explained. We derive exact Green's function formalisms for boundary values in
the associated lattice elasticity problems. The computational efficiency is
further enhanced by using a superparticle surface coarsening approximation.
Atomic hoppings simulating surface diffusion are sampled using a multi-step
acceptance-rejection algorithm. It utilizes quick estimates of the atomic
elastic energies from extensively tabulated values modulated by the local
strain. A parameter controls the compromise between accuracy and efficiency of
the acceptance-rejection algorithm.Comment: 10 pages, 4 figures, submitted to Proceedings of Barrett Lectures
2007, Journal of Scientific Computin
Microwave Ionization of an Atomic Electron Wave Packet
A short microwave pulse is used to ionize a lithium Rydberg wave packet launched from the core at a well-defined phase of the field. We observe a strong dependence on the relative phase between the motion of the wave packet and the oscillations of the field. This phase dependent ionization is also studied as a function of the relative frequency. Our experimental observations are in good qualitative agreement with a one-dimensional classical model of wave packet ionization
Catalogue of programmes and policies related to regional development and infrastructure ("Baseline assessment")
A baseline assessment, an impact and vulnerability assessment of EU investments in infrastructure and a mitigation potential analysis shall help to generate policy options, which will be appraised in the subsequent phase of the project. In this report we set the stage for the further tasks. The report identifies critical questions and resulting implications concerning the assessment of impacts and vulnerability of infrastructure and infrastructure investments in the EU; describes EU Cohesion Policy; o details the current design of the Structural Funds; describes the issue of environmental and climate change mainstreaming from an EU perspective; presents an exploratory analysis of evidence for climate policy integration based on Member States National Strategic Reference Frameworks (NSRFs); and finally addresses the main research and knowledge gaps that will be addressed in subsequent research within this work package
Microwave Ionization of an Atomic Electron Wave Packet
A short microwave pulse is used to ionize a lithium Rydberg wave packet launched from the core at a well-defined phase of the field. We observe a strong dependence on the relative phase between the motion of the wave packet and the oscillations of the field. This phase dependent ionization is also studied as a function of the relative frequency. Our experimental observations are in good qualitative agreement with a one-dimensional classical model of wave packet ionization
A Game of Attribute Decomposition for Software Architecture Design
Attribute-driven software architecture design aims to provide decision
support by taking into account the quality attributes of softwares. A central
question in this process is: What architecture design best fulfills the
desirable software requirements? To answer this question, a system designer
needs to make tradeoffs among several potentially conflicting quality
attributes. Such decisions are normally ad-hoc and rely heavily on experiences.
We propose a mathematical approach to tackle this problem. Game theory
naturally provides the basic language: Players represent requirements, and
strategies involve setting up coalitions among the players. In this way we
propose a novel model, called decomposition game, for attribute-driven design.
We present its solution concept based on the notion of cohesion and
expansion-freedom and prove that a solution always exists. We then investigate
the computational complexity of obtaining a solution. The game model and the
algorithms may serve as a general framework for providing useful guidance for
software architecture design. We present our results through running examples
and a case study on a real-life software project.Comment: 23 pages, 5 figures, a shorter version to appear at 12th
International Colloquium on Theoretical Aspects of Computing (ICTAC 2015
Measurement of Refractive Index Change of Optical Fiber Core Induced by Femtosecond Laser Scanning
We report a new method to measure the refractive index change in optical fiber core induced by femtosecond (fs) laser exposure. An in-line Fabry-Perot interferometer, serving as the measurement platform, is constructed on a commercial single-mode optical fiber by onestep femtosecond (fs) laser fabrication. A positive refractive index change is observed and measured accurately as the laser pulse energy surpasses the ablation threshold
Characterization of the Hamamatsu R11410-10 3-Inch Photomultiplier Tube for Liquid Xenon Dark Matter Direct Detection Experiments
To satisfy the requirements of the next generation of dark matter detectors
based on the dual phase TPC, Hamamatsu, in close collaboration with UCLA, has
developed the R11410-10 photomultipler tube. In this work, we present the
detailed tests performed on this device. High QE (>30%) accompanied by a low
dark count rate (50 Hz at 0.3 PE) and high gain (10^7) with good single PE
resolution have been observed. A comprehensive screening measurement campaign
is ongoing while the manufacturer quotes a radioactivity of 20 mBq/PMT. These
characteristics show the R11410-10 to be particularly suitable for the
forthcoming zero background liquid xenon detectors.Comment: 19 pages, 18 figure
Alcohol Use, Abuse, and Dependency in Shanghai
The use of alcohol for social and ceremonial occasions was recorded in Chinese history as early as 1760 B.C. during the Yin Dynasty (Ci-Hai Encyclopedia, 1979:936). The cultural tradition of ancient China placed alcoholic beverages at the center of social occasions, which presumably was the origin of the adage: Without wine, there is no li (or etiquette). Thus, the use of alcoholic beverages has always been accompanied by the concept of propriety and the discharging of one\u27s role obligations m social functions, rather than that of personal indulgence
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