6,454 research outputs found
Emerging Global Health Crisis of Our Times- Climate Change
The progress of the human race over the last 200 years is unprecedented in recent history. Rapid industrialization, urbanization, and consumerism have made lives easier for humankind. Still, these changes come at a very high price. We never anticipated that we will have to pay the price in the form of climate change and global warming. Our planet, the earth is getting warmer by 0.85 ̊centigrde annually for the last one hundred and seventy years. Hence, glaciers are melting faster than ever, water levels are rising, and cities are sinking, while greenhouse gas emission numbers are at their highest points in human history. Unfortunately we humans are living in anthropogenic epoch and are also speeding up the destruction of the earth's ecosystem by being the dominant cause of the warming observed since the 20th century. Deforestation coupled with increased greenhouse gas emissions has led to a surge of heat-waves globally. These environmental disasters not only affect the environment, plants, and land but also have a profound direct and indirect impact on the health of people. In-fact the health impact has already debuted in the form of worsening key health indicators. In Pakistan alone, the 2015 heat-wave claimed the lives of twelve hundred people in Sindh province. Due to variable rainfall patterns that affect the availability of fresh water, it also affects food production & delivery and brings on the drought. Quality of air, clean drinking water, and availability of food are the top three indicators most influenced by these disasters. Coupled with these, the more than the frequent occurrence of natural calamities; tsunamis, wildfires, snowstorms, and extremes of temperatures has put an extra financial burden on already, stretched to limits budgets of health
Quantum Communication Complexity using the Quantum Zeno Effect
The quantum Zeno effect (QZE) is the phenomenon where the unitary evolution
of a quantum state is suppressed e.g. due to frequent measurements. Here, we
investigate the use of the QZE in a class of communication complexity problems
(CCPs). Quantum entanglement is known to solve certain CCPs beyond classical
constraints. However, recent developments have yielded CCPs where
super-classical results can be obtained using only communication of a single
d-level quantum state (qudit) as a resource. In the class of CCPs considered
here, we show quantum reduction of complexity in three ways: using i)
entanglement and the QZE, ii) single qudit and the QZE, iii) single qudit. The
final protocol is motivated by experimental feasibility, and we have performed
a proof of concept experimental demonstration
Reconstruction of freeform surfaces for metrology
The application of freeform surfaces has increased since their complex shapes closely express a product's functional specifications and their machining is obtained with higher accuracy. In particular, optical surfaces exhibit enhanced performance especially when they take aspheric forms or more complex forms with multi-undulations. This study is mainly focused on the reconstruction of complex shapes such as freeform optical surfaces, and on the characterization of their form. The computer graphics community has proposed various algorithms for constructing a mesh based on the cloud of sample points. The mesh is a piecewise linear approximation of the surface and an interpolation of the point set. The mesh can further be processed for fitting parametric surfaces (Polyworks® or Geomagic®). The metrology community investigates direct fitting approaches. If the surface mathematical model is given, fitting is a straight forward task. Nonetheless, if the surface model is unknown, fitting is only possible through the association of polynomial Spline parametric surfaces. In this paper, a comparative study carried out on methods proposed by the computer graphics community will be presented to elucidate the advantages of these approaches. We stress the importance of the pre-processing phase as well as the significance of initial conditions. We further emphasize the importance of the meshing phase by stating that a proper mesh has two major advantages. First, it organizes the initially unstructured point set and it provides an insight of orientation, neighbourhood and curvature, and infers information on both its geometry and topology. Second, it conveys a better segmentation of the space, leading to a correct patching and association of parametric surfaces.EMR
Noise-robust preparation contextuality shared between any number of observers via unsharp measurements
Multiple observers who independently harvest nonclassical correlations from a
single physical system share the system's ability to enable quantum
correlations. We show that any number of independent observers can share the
preparation contextual outcome statistics enabled by state ensembles in quantum
theory. Furthermore, we show that even in the presence of any amount of white
noise, there exists quantum ensembles that enable such shared preparation
contextuality. The findings are experimentally realised by applying sequential
unsharp measurements to an optical qubit ensemble which reveals three shared
demonstrations of preparation contextuality.Comment: H. A. and N. W. contributed equally to this wor
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