30,068 research outputs found
An Audience Centred Approach to Business Process Reengineering
This paper describes a method for process modelling which is designed to provide guidance to the business process modeller. The method has evolved from our experience of attempting to apply software process modelling approaches to business processes. A major influence on the method has been our observations that a pragmatic approach to notation selection is required in order to maintain a
meaningful dialogue with end-users. Business process modelling methods typically fall into two camps. General methods attempt to describe the managerial activities which surround the modelling itself (Coulson-Thomas, 94; GISIP, 95). Specific methods, on the other hand, tend to
concentrate on the details of a particular notational approach. However, as with programming languages or design methods, no single notational approach is best suited to all problems. Ideally, the process modeller should be able to incorporate the appropriate notational approach into some coherent generic modelling method.This paper addresses the needs of the modeller at the detailed level without prescribing a specific notation. This is achieved by describing categories of modelling activities which the modeller should undertake within process modelling, and
suggesting how notations may be used within these categories. Our method is generally applicable, and is illustrated here by models of processes within the
Construction industry
Short turn-around intercontinental clock synchronization using very-long-baseline interferometry
During the past year work was accomplished to bring into regular operation a VLBI system for making intercontinental clock comparisons with a turn around of a few days from the time of data taking. Earlier VLBI systems required several weeks to produce results. The present system, which is not yet complete, incorporates a number of refinements not available in earlier systems, such as dual frequency inosopheric delay cancellation and wider synthesized bandwidths with instrumental phase calibration
Heavy-tailed statistics in short-message communication
Short-message (SM) is one of the most frequently used communication channels
in the modern society. In this Brief Report, based on the SM communication
records provided by some volunteers, we investigate the statistics of SM
communication pattern, including the interevent time distributions between two
consecutive short messages and two conversations, and the distribution of
message number contained by a complete conversation. In the individual level,
the current empirical data raises a strong evidence that the human activity
pattern, exhibiting a heavy-tailed interevent time distribution, is driven by a
non-Poisson nature.Comment: 4 pages, 4 figures and 1 tabl
Role of Activity in Human Dynamics
The human society is a very complex system; still, there are several
non-trivial, general features. One type of them is the presence of power-law
distributed quantities in temporal statistics. In this Letter, we focus on the
origin of power-laws in rating of movies. We present a systematic empirical
exploration of the time between two consecutive ratings of movies (the
interevent time). At an aggregate level, we find a monotonous relation between
the activity of individuals and the power-law exponent of the interevent-time
distribution. At an individual level, we observe a heavy-tailed distribution
for each user, as well as a negative correlation between the activity and the
width of the distribution. We support these findings by a similar data set from
mobile phone text-message communication. Our results demonstrate a significant
role of the activity of individuals on the society-level patterns of human
behavior. We believe this is a common character in the interest-driven human
dynamics, corresponding to (but different from) the universality classes of
task-driven dynamics.Comment: 5 pages, 6 figures. Accepted by EP
Engineering entanglement for metrology with rotating matter waves
Entangled states of rotating, trapped ultracold bosons form a very promising scenario for quantum metrology. In order to employ such states for metrology, it is vital to understand their detailed form and the enhanced accuracy with which they could measure phase, in this case generated through rotation. In this work, we study the rotation of ultracold bosons in an asymmetric trapping potential beyond the lowest Landau level (LLL) approximation. We demonstrate that while the LLL can identify reasonably the critical frequency for a quantum phase transition and entangled state generation, it is vital to go beyond the LLL to identify the details of the state and quantify the quantum Fisher information (which bounds the accuracy of the phase measurement). We thus identify a new parameter regime for useful entangled state generation, amenable to experimental investigation
Optimal Survey Strategies and Predicted Planet Yields for the Korean Microlensing Telescope Network
The Korean Microlensing Telescope Network (KMTNet) will consist of three 1.6m
telescopes each with a 4 deg^{2} field of view (FoV) and will be dedicated to
monitoring the Galactic Bulge to detect exoplanets via gravitational
microlensing. KMTNet's combination of aperture size, FoV, cadence, and
longitudinal coverage will provide a unique opportunity to probe exoplanet
demographics in an unbiased way. Here we present simulations that optimize the
observing strategy for, and predict the planetary yields of, KMTNet. We find
preferences for four target fields located in the central Bulge and an exposure
time of t_{exp} = 120s, leading to the detection of ~2,200 microlensing events
per year. We estimate the planet detection rates for planets with mass and
separation across the ranges 0.1 <= M_{p}/M_{Earth} <= 1000 and 0.4 <= a/AU <=
16, respectively. Normalizing these rates to the cool-planet mass function of
Cassan (2012), we predict KMTNet will be approximately uniformly sensitive to
planets with mass 5 <= M_{p}/M_{Earth} <= 1000 and will detect ~20 planets per
year per dex in mass across that range. For lower-mass planets with mass 0.1 <=
M_{p}/M_{Earth} < 5, we predict KMTNet will detect ~10 planets per year. We
also compute the yields KMTNet will obtain for free-floating planets (FFPs) and
predict KMTNet will detect ~1 Earth-mass FFP per year, assuming an underlying
population of one such planet per star in the Galaxy. Lastly, we investigate
the dependence of these detection rates on the number of observatories, the
photometric precision limit, and optimistic assumptions regarding seeing,
throughput, and flux measurement uncertainties.Comment: 29 pages, 31 figures, submitted to ApJ. For a brief video explaining
the key results of this paper, please visit:
https://www.youtube.com/watch?v=e5rWVjiO26
Use of high-dimensional spectral data to evaluate organic matter, reflectance relationships in soils
Recent breakthroughs in remote sensing technology have led to the development of a spaceborne high spectral resolution imaging sensor, HIRIS, to be launched in the mid-1990s for observation of earth surface features. The effects of organic carbon content on soil reflectance over the spectral range of HIRIS, and to examine the contributions of humic and fulvic acid fractions to soil reflectance was evaluated. Organic matter from four Indiana agricultural soils was extracted, fractionated, and purified, and six individual components of each soil were isolated and prepared for spectral analysis. The four soils, ranging in organic carbon content from 0.99 percent, represented various combinations of genetic parameters such as parent material, age, drainage, and native vegetation. An experimental procedure was developed to measure reflectance of very small soil and organic component samples in the laboratory, simulating the spectral coverage and resolution of the HIRIS sensor. Reflectance in 210 narrow (10 nm) bands was measured using the CARY 17D spectrophotometer over the 400 to 2500 nm wavelength range. Reflectance data were analyzed statistically to determine the regions of the reflective spectrum which provided useful information about soil organic matter content and composition. Wavebands providing significant information about soil organic carbon content were located in all three major regions of the reflective spectrum: visible, near infrared, and middle infrared. The purified humic acid fractions of the four soils were separable in six bands in the 1600 to 2400 nm range, suggesting that longwave middle infrared reflectance may be useful as a non-destructive laboratory technique for humic acid characterization
Invariant quantum discord in qubit-qutrit systems under local dephasing
We investigate the dynamics of quantum discord and entanglement for a
class of mixed qubit-qutrit states assuming that only the qutrit is under the action of a dephasing channel. We demonstrate that even though the entanglement in the qubit-qutrit state disappears in a finite time interval, partial coherence left in the system enables quantum discord to remain invariant throughout the whole time evolution
Discovery of Griffiths phase in itinerant magnetic semiconductor Fe_{1-x}Co_xS_2
Critical points that can be suppressed to zero temperature are interesting
because quantum fluctuations have been shown to dramatically alter electron gas
properties. Here, the metal formed by Co doping the paramagnetic insulator
FeS, FeCoS, is demonstrated to order ferromagnetically at
where we observe unusual transport, magnetic, and
thermodynamic properties. We show that this magnetic semiconductor undergoes a
percolative magnetic transition with distinct similarities to the Griffiths
phase, including singular behavior at and zero temperature.Comment: 10 pages, 4 figure
- …