1,313 research outputs found
PrePost(+): An efficient N-lists-based algorithm for mining frequent itemsets via Children-Parent Equivalence pruning
No full textN-list is a novel data structure proposed in recent years. It has been proven to be very efficient for mining frequent itemsets. In this paper, we present PrePost(+), a high-performance algorithm for mining frequent itemsets. It employs N-list to represent itemsets and directly discovers frequent itemsets using a set-enumeration search tree. Especially, it employs an efficient pruning strategy named Children-Parent Equivalence pruning to greatly reduce the search space. We have conducted extensive experiments to evaluate PrePost(+) against three state-of-the-art algorithms, which are PrePost, FIN, and FP-growth*, on six various real datasets. The experimental results show that PrePost(+) is always the fastest one on all datasets. Moreover, PrePost(+) also demonstrates good performance in terms of memory consumption since it use only a litter more memory than FP-growth* and less memory than PrePost and FIN. (C) 2015 Elsevier Ltd. All rights reserved.National Natural Science Foundation of China [61170091]SCI(E)[email protected]; [email protected]
The savings collapse during the transition in Eastern Europe
No full textThe authors assess the presence and extent of involuntary savings by comparing the predicted savings rates of market economies with those of the pre-transition economies. On balance, predicted savings rates fell short of actual savings rates, especially for the former Soviet Union and the Baltics -- providing some support for the notion of excessive pre-transition savings. Comparing the savings behavior of market economies and transition economies, they found substantial similarities, except for a negative link between savings and GDP growth. As the fastest-growing transition economies are at the bottom of the adjustment J-curve, the finding is consistent with consumption smoothing. Finally, they explored whether differences in the extent of economic liberalization affected savings rates in the cross-section of transition economies. They found that liberalization is associated with lower savings, with a one-year lag. To the extent that liberalization is perceived as an indicator of likely future growth, this behavior is consistent with smoothing in the face of a J-curve change in output.Insurance Law,Banks&Banking Reform,Economic Theory&Research,Environmental Economics&Policies,Insurance&Risk Mitigation,Environmental Economics&Policies,Banks&Banking Reform,Economic Theory&Research,Insurance&Risk Mitigation,Rural Poverty Reduction
Development of Polarized Photocathodes for the Linear Collider
No full textIn prior years a Wisconsin-SLAC collaboration developed polarized photocathodes which were used for the SLAC SLD and fixed target programs. Currently, the R&D program goal is the development of a polarized electron source (PES) which meets the ILC requirements for polarization, charge, lifetime, and pulse structure. There are two parts to this program. One part is the continued improvement of photocathode structures with higher polarization. The second part is the design and development of the laser system used to drive the photocathode. The long pulse train for the ILC introduces new challenges for the PES. More reliable and stable operation of the PES may be achievable if appropriate R&D is carried out for higher voltage operation and for a simpler photocathode load-lock system. The collaboration with SLAC is through the Polarized Photocathode Research Collaboration (PPRC). Senior SLAC personnel include T. Maruyama, J. Clendenin, R. Kirby, and A. Brachmann
"A novel positioning System for static location estimation employing WLAN in indoor environment"
No full textThis paper describes a positioning algorithm that uses the signal strength, received by a wireless local area network, to determine users position. The system improves positioning accuracy by mitigating the multipath and noise, through an empirical analysis of environment and a prepost curser mitigator. Results, in terms of relative error, are presented for indoor environment
Imrovement of the cold forming technology of the parts such as longeron
No full text© Published under licence by IOP Publishing Ltd. As a result of modeling in LS-PREPOST preprocessor of the program LS-DYNA a range of radii of curvature edge transition matrix (27,5 °≤ R ≤ 48 °) is obtained, which allows to produce defect-free stamping slots for longeron shock absorbers of tractors KAMAZ-5460
Imrovement of the cold forming technology of the parts such as longeron
No full text© Published under licence by IOP Publishing Ltd. As a result of modeling in LS-PREPOST preprocessor of the program LS-DYNA a range of radii of curvature edge transition matrix (27,5 °≤ R ≤ 48 °) is obtained, which allows to produce defect-free stamping slots for longeron shock absorbers of tractors KAMAZ-5460
The Retrospective Pre-Post: A Practical Method to Evaluate Learning from an Educational Program
No full textObjectives: Program evaluation remains a critical but underutilized step in medical education. This study compared traditional and retrospective prepost self-assessment methods to objective learning measures to assess which correlated better to actual learning. Methods: Forty-seven medical students participated in a 4-hour pediatric resuscitation course. They completed pre and post self-assessments on pediatric resuscitation and two distracter topics. Postcourse, students also retrospectively rated their understanding as it was precourse (the retrospective pre instrument). Changes in traditional and retrospective pre- to postcourse self-assessment measures were compared to an objectives-based multiple-choice exam. Results: The traditional pre to post self-assessment means showed an increase from 1.9 of 5 to 3.7 of 5 (p <0.001); the retrospective pre to post scores also increased from 1.9 of 5 to 3.7 of 5 (p <0.001). Although the group means were the same, individual participants demonstrated a response shift by either increasing or decreasing their traditional pre to retrospective pre scores. Scores on the 22-item objective multiple choice test also increased, from a median score of 13.0 to 18.0 (p <0.001). There was no correlation between the change in self-assessments and objective measures as demonstrated by a Spearman correlation of -0.02 and -0.13 for the traditional and retrospective prepost methods, respectively. Students reported fewer changes on the two distracters using the retrospective prepost versus the traditional method (11 vs. 29). Conclusions: Students were able to accurately identify, but not quantify, learning using either traditional or retrospective prepost self-assessment measures. Retrospective prepost self-assessment was more accurate in excluding perceived change in understanding of subject matter that was not taught
Analysis and comparison of some aquatic motor behaviors in young children
No full textSeveral studies considered aquatic motor sequences in young
children and their relations with some aspects of aquatic psychomotor
development. The aim of this study was to understand
if spontaneous swim movements of the child can evolve
into an effective action, after a “keep doing” and a “free exploration”
based methodological approach. Three groups of ten
children, different in age (4-12 months, 12-24 months, 24-36
months), were studied. The presence of some motor skills pre
and post a period of 10 events of free experience in a swimming
pool were detected. No differences were found in the prepost
comparison within each group. Differences resulted in the
comparison of the children aged 4-12 versus 24-36 months and
in the children aged 12-24 versus 24-36 months
Measurements of R(b) with impact parameters and displaced vertices
No full textWe present measurements of Rb using the SLD at the SLC. The analyses use 2D and 3D impact parameter tags and a displaced 3D vertex tag which all exploit the small size and stability of the e(+)e(-) interaction point and the precision 3D CCD pixel vertex detector to achieve high -tagging efficiencies and purities. The combined measurement yields R(b) = 0.229 +/- 0.011 and is consistent with standard model predictions
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