4,342 research outputs found
Data-driven detection of multi-messenger transients
The primary challenge in the study of explosive astrophysical transients is
their detection and characterisation using multiple messengers. For this
purpose, we have developed a new data-driven discovery framework, based on deep
learning. We demonstrate its use for searches involving neutrinos, optical
supernovae, and gamma rays. We show that we can match or substantially improve
upon the performance of state-of-the-art techniques, while significantly
minimising the dependence on modelling and on instrument characterisation.
Particularly, our approach is intended for near- and real-time analyses, which
are essential for effective follow-up of detections. Our algorithm is designed
to combine a range of instruments and types of input data, representing
different messengers, physical regimes, and temporal scales. The methodology is
optimised for agnostic searches of unexpected phenomena, and has the potential
to substantially enhance their discovery prospects.Comment: 16 page
Feasibility of remote evaporation and precipitation estimates
Remote sensing by means of stereo images obtained from flown cameras and scanners provides the potential to monitor the dynamics of pollutant mixing over large areas. Moreover, stereo technology may permit monitoring of pollutant concentration and mixing with sufficient detail to ascertain the structure of a polluted air mass. Consequently, stereo remote systems can be employed to supply data to set forth adequate regional standards on air quality. A method of remote sensing using stereo images is described. Preliminary results concerning the planar extent of a plume based on comparison with ground measurements by an alternate method, e.g., remote hot-wire anemometer technique, are supporting the feasibility of using stereo remote sensing systems
Planning effort as an effective risk management tool
In project management, high levels of risk are considered to be a significant obstacle for project success. This paper investigates whether improving the project plan can lead to improved success for high-risk projects. A quality of planning index was designed to explore how the presence of high risk affects the quality of planning and project success. The index includes managerial aspects such as costs, human resources, procurement and quality, as well as organizational support aspects based on organization maturity models. In a field study based on data collected from 202 project managers regarding their most recent projects, it was found that the levels of risk at the beginning of projects has no effect on their final success. Drilling down to find an explanation for this surprising phenomenon, we found that in the presence of high risk, project managers significantly improve their project plans. Hence, in high-risk projects, better project plans improve all four dimensions of project success: schedule overrun, cost overrun, technical performance and customer satisfaction. However, in low-risk projects, better project plans did not contribute to reducing schedule or cost overruns. In other words, while endless risk management tools are developed, we found that improving the project plan is a more effective managerial tool in dealing with high-risk projects. Finally, the paper presents the most common planning tools currently being used in high-risk projects
The MICRO-BOSS scheduling system: Current status and future efforts
In this paper, a micro-opportunistic approach to factory scheduling was described that closely monitors the evolution of bottlenecks during the construction of the schedule, and continuously redirects search towards the bottleneck that appears to be most critical. This approach differs from earlier opportunistic approaches, as it does not require scheduling large resource subproblems or large job subproblems before revising the current scheduling strategy. This micro-opportunistic approach was implemented in the context of the MICRO-BOSS factory scheduling system. A study comparing MICRO-BOSS against a macro-opportunistic scheduler suggests that the additional flexibility of the micro-opportunistic approach to scheduling generally yields important reductions in both tardiness and inventory
Effects of turbulence on laminar separation on aerodynamic surfaces such as airfoils and compressor blading
Activities report include (1) completion of measurements of turbulence amplification in flow about a circular cylinder; (2) initiation of the measurements of turbulence characteristics in flow about a single symmetric airfoil; and, (3) further examination of various matching numerical methods. Emphasis is placed on the experimental program conducted to obtain data on the amplification of the oncoming turbulence and its management
Impact of a non-Gaussian density field on Sunyaev-Zeldovich observables
The main statistical properties of the Sunyaev-Zeldovich (S-Z) effect - the
power spectrum, cluster number counts, and angular correlation function - are
calculated and compared within the framework of two density fields which differ
in their predictions of the cluster mass function at high redshifts. We do so
for the usual Press and Schechter mass function, which is derived on the basis
of a Gaussian density fluctuation field, and for a mass function based on a
chi^2 distributed density field. These three S-Z observables are found to be
very significantly dependent on the choice of the mass function. The different
predictions of the Gaussian and non-Gaussian density fields are probed in
detail by investigating the behaviour of the three S-Z observables in terms of
cluster mass and redshift. The formation time distribution of clusters is also
demonstrated to be sensitive to the underlying mass function. A
semi-quantitative assessment is given of its impact on the concentration
parameter and the temperature of intracluster gas.Comment: 17 pages, 11 figures, accepted for publication in MNRA
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