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2.
On July 24, 2010, 21 people died and more than 500 were injured in a stampede at the Loveparade, a music festival, in Duisburg, Germany. Although this tragic incident is but one among many terrible crowd disasters that occur during pilgrimage, sports events, or other mass gatherings, it stands out for it has been well documented: there were a total of seven security cameras monitoring the Loveparade and the chain of events that led to disaster was meticulously reconstructed.In this paper, we present an automatic, video-based analysis of the events in Duisburg. While physical models and simulations of human crowd behavior have been reported before, to the best of our knowledge, automatic vision systems that detect congestions and dangerous crowd turbulences in real world settings were not reported yet. Derived from lessons learned from the video footage of the Loveparade, our system is able to detect motion patterns that characterize crowd behavior in stampedes. Based on our analysis, we propose methods for the detection and early warning of dangerous situations during mass events. Since our approach mainly relies on optical flow computations, it runs in real-time and preserves privacy of the people being monitored. 相似文献
3.
The mechanism of low-temperature plastic deformation is controlled by thermally activated dislocation movements. An evolutionary
constitutive law based on the principles of deformation kinetics is described in this article. The constitutive law is expressed
with a sinh function designed for computational efficiency. It is derived from rigorously defined kinetics principles. The
approximation involved in the sinh function is defined so that in applications an exact evaluation can be made of the validity
limits. The system of the constitutive law and the external constraints lead to the operational equations. Applications are
developed for constant strain-rate loading, constant stress-rate loading, stress relaxation, creep, and ratchetting processes.
The analysis provides a unified treatment for low-temperature plastic deformation. 相似文献
4.
Csilla Lakatos Katalin Czifrák József Karger‐Kocsis Lajos Daróczi Miklós Zsuga Sándor Kéki 《应用聚合物科学杂志》2016,133(43)
Crosslinked polyurethanes (PUs) containing irreversible (allophanate) and reversible Diels‐Alder chemical bonds were synthesized using various diisocyanates (methylene diphenyl diisocyanate MDI, 1,6‐hexamethylenediisocyanate HDI) and poly(?‐caprolactone) ((PCL) with different molecular weights (Mn = 10 kg/mol, 25 kg/mol, 50 kg/mol) as diol component. The melting/crystallization of PCL and the reversible DA bonds acted as temperature‐activated switches for shape memory performances, while allophanate network provided the permanent crosslinks for these PUs. The reversible DA bonds were obtained by the reaction of diisocyanate‐ended prepolymers with furfurylamine (FA) followed by the addition of bismaleimide (BMI). The permanent crosslinks between the linear chains containing DA bonds were achieved using additional amounts of diisocyanates (MDI or HDI). The above reaction path was supported by infrared spectroscopic results and swelling experiments. Tensile mechanical and shape memory properties in tension of the PUs were determined and discussed as a function of composition and crosslink densities deduced from swelling and dynamic mechanical analysis. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44145. 相似文献
5.
Aleksandra Szydłowska-Czerniak György Karlovits Csilla Dianoczki Katalin Recseg Edward Szłyk 《Journal of the American Oil Chemists' Society》2008,85(2):141-149
The oxygen radical absorbance capacity (ORAC) and the ferric reducing antioxidant power (FRAP) methods were used for the determination
of antioxidant capacities (AC) of rapeseed oils at different steps of technological process and olive oils. The mean ORAC
and FRAP results obtained for rapeseed oils (1,106–160 and 552–95.6 μmol TE/100 g) were higher than for olive oils (949–123
and 167–32.1 μmol TE/100 g). Although, FRAP values were lower than ORAC values for all studied oils, there is a linear and
significant correlation between these two analytical methods (r = 0.9665 and 0.9298, P < 0.0005) for rapeseed and olive oils, respectively). Also, total phenolic compounds in rapeseed oils and olives correlated
with antioxidant capacities (correlation coefficient ranged between 0.9470 and 0.8049). The refining process of rapeseed oils
decreased the total phenolics content and antioxidant capacities by about 80%. 相似文献
6.
A new antibacterial material has been elaborated by grafting mesoarylporphyrin on cotton fabric by the means of cellulose azidation followed by “Click-Chemistry” reaction with acetylenic porphyrin. Azidation and functionalization have been checked by ATR-FTIR spectroscopy. Under irradiation with visible light, this material displayed an antibacterial activity against representative strains of Escherichia coli and Staphylococcus aureus. This new photobactericidal textile has potential for industrial, medical, and household applications. 相似文献
7.
Imola Wilhelm Judit Molnár Csilla Fazakas János Haskó István A. Krizbai 《International journal of molecular sciences》2013,14(1):1383-1411
The majority of brain metastases originate from lung cancer, breast cancer and malignant melanoma. In order to reach the brain, parenchyma metastatic cells have to transmigrate through the endothelial cell layer of brain capillaries, which forms the morphological basis of the blood-brain barrier (BBB). The BBB has a dual role in brain metastasis formation: it forms a tight barrier protecting the central nervous system from entering cancer cells, but it is also actively involved in protecting metastatic cells during extravasation and proliferation in the brain. The mechanisms of interaction of cancer cells and cerebral endothelial cells are largely uncharacterized. Here, we provide a comprehensive review on our current knowledge about the role of junctional and adhesion molecules, soluble factors, proteolytic enzymes and signaling pathways mediating the attachment of tumor cells to brain endothelial cells and the transendothelial migration of metastatic cells. Since brain metastases represent a great therapeutic challenge, it is indispensable to understand the mechanisms of the interaction of tumor cells with the BBB in order to find targets of prevention of brain metastasis formation. 相似文献
8.
9.
While the analytical philosophy of science regards inconsistent theories as disastrous, Chomsky allows for the temporary tolerance of inconsistency between the hypotheses and the data. However, in linguistics there seem to be several types of inconsistency. The present paper aims at the development of a novel metatheoretical framework which provides tools for the representation and evaluation of inconsistencies in linguistic theories. The metatheoretical model relies on a system of paraconsistent logic and distinguishes between strong and weak inconsistency. Strong inconsistency is destructive in that it leads to logical chaos. In contrast, weak inconsistency may be constructive, because it is capable of accounting for the simultaneous presence of seemingly incompatible structures. However, paraconsistent logic cannot grasp the dynamism of the emergence and resolution of weak inconsistencies. Therefore, the metatheoretical approach is extended to plausible argumentation. The workability of this metatheoretical model is tested with the help of a detailed case study on an analysis of discontinuous constituents in Government-Binding Theory. 相似文献
10.
Davidson Oranit B.; Eden Dov; Westman Mina; Cohen-Charash Yochi; Hammer Leslie B.; Kluger Avraham N.; Krausz Moshe; Maslach Christina; O'Driscoll Michael; Perrewé Pamela L.; Quick James Campbell; Rosenblatt Zehava; Spector Paul E. 《Canadian Metallurgical Quarterly》2010,95(5):953
A rigorous quasi-experiment tested the ameliorative effects of a sabbatical leave, a special case of respite from routine work. We hypothesized that (a) respite increases resource level and well-being and (b) individual differences and respite features moderate respite effects. A sample of 129 faculty members on sabbatical and 129 matched controls completed measures of resource gain, resource loss, and well-being before, during, and after the sabbatical. Among the sabbatees, resource loss declined and resource gain and well-being rose during the sabbatical. The comparison group showed no change. Moderation analysis revealed that those who reported higher respite self-efficacy and greater control, were more detached, had a more positive sabbatical experience, and spent their sabbatical outside their home country enjoyed more enhanced well-being than others. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献