1,530 research outputs found
Longitudinal dependence of the interplanetary perturbation produced by energetic type 4 solar flares and of the associated cosmic ray modulation
One of the most significant features of the flare-associated Forbush decreases (Fds) in the galatctic cosmic ray (c.r.) is the so-called East-West asymmetry: the solar flares (Sfs) observed in the Eastern or central region of the solar disk exhibit a higher probability to cause large Fds than the Sfs occurring in the Western portion of the disk. In particular the interplanetary perturbations generated by Type IV Sfs depress the c.r. intensity in a vast spiral cone-like region (modulated region) which extends along the interplanetary magnetic field from the neighborhood of the active region to the advancing perturbation, and that, immediately after the flare-generated perturbation, the maximum c.r. modulation is observed between 0 and 40 deg. W of the meridian plane crossings the flare site at time of flare (flare's meridian plane)
Home Values and Firm Behavior
The homes of firm owners are an important source of finance for ongoing businesses. We use UK microdata to show that a £1 increase in the value of the homes of a firm's directors increases the firm's investment by £0.03. This effect is concentrated among firms whose directors' homes are valuable relative to the firm's assets, that are financially constrained, and that have directors who are personally highly levered. An aggregation exercise shows that directors' homes are as important as corporate property for collateral driven fluctuations in aggregate investment demand
Reactions to extreme events: moving threshold model
In spite of precautions to avoid the harmful effects of extreme events, we
experience recurrently phenomena that overcome the preventive barriers. These
barriers usually increase drastically right after the occurrence of such
extreme events, but steadily decay in their absence. In this paper we consider
a simple model that mimics the evolution of the protection barriers to study
the efficiency of the system's reaction to extreme events and how it changes
our perception of the sequence of extreme events itself. We obtain that the
usual method of fighting extreme events introduces a periodicity in their
occurrence and is generally less efficient than the use of a constant barrier.
On the other hand, it shows a good adaptation to the presence of slow
non-stationarities.Comment: 14 pages and 7 figure
Optimization of Specimen and Tabs Geometry for Quasi-Static and Fatigue Testing of Composites in UD 90° Laminates
Fracture mechanics description of the defect in rolling cylinder
project m- IPMinfra (CZ.02.1.01/0.0/0.0/16_013/0001823
Methods for identifying high-redshift galaxy cluster candidates
Recent theories linked long gamma ray bursts (GRBs) to galaxies with rapid star formation or starburst; thus, we expect that long GRBs (LGRBs) are more frequent in midcluster galaxies where mergers and tidal interactions between gas-rich galaxies are more likely to occur. Yet there is no galaxy cluster known to be associated with LGRBs. We demonstrate that, based on deep, single-band Subaru Hyper Suprime-Cam observations, we may provide constraints on photometric redshifts of groups of galaxies. We compare three methods: cosmological approach, pseudoinverse matrix, and random forests to estimate galaxy and quasar redshifts. Comparing our results to spectroscopic redshifts of Sloan Digital Sky Survey's-detected extragalactic sources, random forests may provide the highest accuracy with as low as 17 percentage error. This is a powerful method to find clusters to place GRB host galaxies in their local environment
A narrative review of adaptive testing and its application to medical education.
Adaptive testing has a long but largely unrecognized history. The advent of computer-based testing has created new opportunities to incorporate adaptive testing into conventional programmes of study. Relatively recently software has been developed that can automate the delivery of summative assessments that adapt by difficulty or content. Both types of adaptive testing require a large item bank that has been suitably quality assured. Adaptive testing by difficulty enables more reliable evaluation of individual candidate performance, although at the expense of transparency in decision making, and requiring unidirectional navigation. Adaptive testing by content enables reduction in compensation and targeted individual support to enable assurance of performance in all the required outcomes, although at the expense of discovery learning. With both types of adaptive testing, candidates are presented a different set of items to each other, and there is the potential for that to be perceived as unfair. However, when candidates of different abilities receive the same items, they may receive too many they can answer with ease, or too many that are too difficult to answer. Both situations may be considered unfair as neither provides the opportunity to demonstrate what they know. Adapting by difficulty addresses this. Similarly, when everyone is presented with the same items, but answer different items incorrectly, not providing individualized support and opportunity to demonstrate performance in all the required outcomes by revisiting content previously answered incorrectly could also be considered unfair; a point addressed when adapting by content. We review the educational rationale behind the evolution of adaptive testing and consider its inherent strengths and limitations. We explore the continuous pursuit of improvement of examination methodology and how software can facilitate personalized assessment. We highlight how this can serve as a catalyst for learning and refinement of curricula; fostering engagement of learner and educator alike
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