3,783 research outputs found
Integrating Existing Software Toolkits into VO System
Virtual Observatory (VO) is a collection of interoperating data archives and
software tools. Taking advantages of the latest information technologies, it
aims to provide a data-intensively online research environment for astronomers
all around the world.
A large number of high-qualified astronomical software packages and libraries
are powerful and easy of use, and have been widely used by astronomers for many
years. Integrating those toolkits into the VO system is a necessary and
important task for the VO developers.
VO architecture greatly depends on Grid and Web services, consequently the
general VO integration route is "Java Ready - Grid Ready - VO Ready". In the
paper, we discuss the importance of VO integration for existing toolkits and
discuss the possible solutions. We introduce two efforts in the field from
China-VO project, "gImageMagick" and " Galactic abundance gradients statistical
research under grid environment". We also discuss what additional work should
be done to convert Grid service to VO service.Comment: 9 pages, 3 figures, will be published in SPIE 2004 conference
proceeding
Order Statistics Approaches to Unobserved Heterogeneity in Auctions
We establish nonparametric identification of auction models with continuous
and nonseparable unobserved heterogeneity using three consecutive order
statistics of bids. We then propose sieve maximum likelihood estimators for the
joint distribution of unobserved heterogeneity and the private value, as well
as their conditional and marginal distributions. Lastly, we apply our
methodology to a novel dataset from judicial auctions in China. Our estimates
suggest substantial gains from accounting for unobserved heterogeneity when
setting reserve prices. We propose a simple scheme that achieves nearly optimal
revenue by using the appraisal value as the reserve price
A framework for multi-objective optimisation based on a new self-adaptive particle swarm optimisation algorithm
This paper develops a particle swarm optimisation (PSO) based framework for multi-objective optimisation (MOO). As a part of development, a new PSO method, named self-adaptive PSO (SAPSO), is first proposed. Since the convergence of SAPSO determines the quality of the obtained Pareto front, this paper analytically investigates the convergence of SAPSO and provides a parameter selection principle that guarantees the convergence. Leveraging the proposed SAPSO, this paper then designs a SAPSO-based MOO framework, named SAMOPSO. To gain a well-distributed Pareto front, we also design an external repository that keeps the non-dominated solutions. Next, a circular sorting method, which is integrated with the elitist-preserving approach, is designed to update the external repository in the developed MOO framework. The performance of the SAMOPSO framework is validated through 12 benchmark test functions and a real-word MOO problem. For rigorous validation, the performance of the proposed framework is compared with those of four well-known MOO algorithms. The simulation results confirm that the proposed SAMOPSO outperforms its contenders with respect to the quality of the Pareto front over the majority of the studied cases. The non-parametric comparison results reveal that the proposed method is significantly better than the four algorithms compared at the confidence level of 90% over the 12 test functions
Buddhist monasteries facilitated landscape conservation on the Qinghai-Tibetan Plateau
Context:
The Sanjiangyuan region of the Qinghai-Tibetan Plateau—also known as the “Three Rivers’ Headwaters”—is the origin of the Yellow, Yangtze, and Mekong Rivers and therefore the key water source for hundreds of millions of downstream residents. Protecting this region’s ecosystems is a key priority for sustainable development in China and Asia. An important social dimension of Sanjiangyuan is the long-established and widespread presence of Tibetan Buddhism, particularly as manifested in the large number of monasteries throughout the region. However, the influence of cultural factors on environmental change remains largely understudied here. /
Objective:
We focus on two types of spatial associations—point-point and point-area features—to quantitatively investigate the effects of Buddhist monasteries on land use/cover change (LUCC) in surrounding landscapes. /
Methods:
We conduct a spatially-explicit analysis of Sanjiangyuan for two periods, 1990–2000 and 2010–2015, to identify and quantify the influence of the presence and spatial distributions of Buddhist monasteries on LUCC compared to village communities that lack monasteries. /
Results:
We found that the presence of monasteries is highly correlated with the preservation of natural ecosystems, specifically of grasslands and forests. Within monastery buffer zones with radii between 1 and 10 km, 7.13–9.30% more grassland area and 7.14–7.47% more forest area remained around monasteries compared to villages. This contrast decreased with increasing distance to the monastery/village. Overall, built-up areas were also much smaller around monasteries than around villages, while unused land was more commonly transformed to forests and grasslands around monasteries. /
Conclusions:
These findings strongly support the idea that Buddhist culture, as manifested through its physical institutions and communities, are instrumental in achieving desired landscape conservation outcomes
Acupuncture Induced Necrotizing Aortitis with Infected Pseudoaneurysm Formation
Necrotizing aortitis is a rare and life-threatening complication of local or generalized bacterial infections and most commonly affects the abdominal aorta. We described a case of a 79-year-old man with an acupuncture-induced bacterial aortitis associated with pseudoaneurysm formation causing near rupture. The patient underwent emergent explolapartomy, resection of the infected aorta, wide debridement of surrounding infected tissues, and extra-anatomic axillary to bifemoral graft bypass. The microbiologic examination revealed Escherichia coli and methicillin resistant Staphylococcus aureus (MRSA). Necrotizing aortitis is very serious and fatal disease, careful history taking as well as rapid diagnosis and urgent treatment are of critical importance
Dr. Yang Zhong: an explorer on the road forever
On the morning of September 25th 2017, grievous news spread from the remote Ordos region of Inner Mongolia to Fudan University campus in Shanghai. Professor Yang Zhong, a famous botanist and the Dean of Fudan University’s graduate school, passed away in a tragic car accident while on a business trip
Attribution of the Hemispheric Asymmetries in Trends of Stratospheric Trace Gases Inferred From Microwave Limb Sounder (MLS) Measurements
Using Microwave Limb Sounder (MLS) satellite observations, ERA‐Interim reanalysis data, and a chemistry transport model simulation, we analyze and investigate the causes of the asymmetric hemispheric trends of N2O, CH4, and HCl in the stratosphere during the period 2004–2012. We find significant hemispheric asymmetries in the trends of these trace gases in the midlatitude middle and lower stratosphere. With regard to N2O and CH4, the enhanced downwelling branch of the residual circulation in the Northern Hemisphere (NH) middle and upper stratosphere transports more N2O/CH4‐poor air from the upper stratosphere to the lower stratosphere. The enhanced poleward meridional branch of the residual circulation in the Southern Hemisphere (SH) stratosphere brings more N2O/CH4‐rich air from lower to middle latitudes. These processes therefore contribute to the negative trends of N2O and CH4 in the NH lower stratosphere and the positive trends in the SH middle stratosphere. A corresponding positive trend is found for HCl in the NH, where the deep branch of the residual circulation located in the middle and upper stratosphere strengthens, bringing more HCl‐rich air downward to the lower stratosphere, while the shallow branch of the residual circulation in the lower stratosphere weakens and leads to enhanced conversion of chlorine‐containing source gases of different lifetimes to HCl. A reversed picture emerges in the SH, where the deep branch of the residual circulation in the middle and upper stratosphere weakens, while the shallow branch in the lower stratosphere strengthens, resulting in less HCl there. In addition, the southward shift of the upwelling branch of the residual circulation in recent decades can partly explain trace gas trends above 20 hPa, while the eddy mixing has a small effect on the trends. Understanding these contributions from different processes to the hemispheric asymmetries in trends of these trace gases can help us to evaluate more accurately future changes in stratospheric composition
2-(1-Methylethoxy)-5-nitrophenyl N-methylcarbamate
In the title compound, C11H14N2O5, the nitro group is approximately coplanar with the benzene ring, making a dihedral angle of 4.26 (17)°. The dihedral angle between the methylcarbamate group and the benzene ring is 72.47 (6)°. There is a strong intermolecular N—H⋯O hydrogen bond between the N and O atoms from adjacent methylcarbamate groups, forming a one-dimensional network along the a axis
Converting metal-organic framework particles from hydrophilic to hydrophobic by an interfacial assembling route
Here we propose to modify the hydrophilicity of metal-organic framework (MOF) particles by an interfacial assembling route, which is based on the surface-active nature of MOF particles. It was found that hydrophilic UiO-66-NH₂ particles can be converted to hydrophobic particles through an oil-water interfacial assembling route. The underlying mechanism for the conversion of UiO-66-NH₂ was investigated by X-ray photoelectron spectroscopy and FT-IR spectroscopy. It was revealed that the close assembly of UiO-66-NH₂ particles at the oil-water interface strengthens the coordination between organic ligands and metal ions, which results in a decrease in the proportion of hydrophilic groups on UiO-66-NH₂ particle surfaces. Hydrophobic UiO-66-NH₂ particles show improved adsorption capacity for dyes in organic solvents compared with pristine UiO-66-NH₂ particles. It is expected that the interfacial assembling route can be applied to the synthesis of different kinds of MOF materials with tunable hydrophilicity or hydrophobicity required for diverse applications
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