Guster D.C.,St. Cloud State University |
Lee O.F.,Northwest University
Journal of Information Technology Research | Year: 2011
Currently, organizations are increasingly aware of the need to protect their computer infrastructure to maintain continuity of operations. This process involves a number of different concerns including: managing natural disasters, equipment failure, and security breaches, poor data management, inadequate design, and complex/impractical design. The purpose of this article is to delineate how virtualization of hosts and cloud computing can be used to address the concerns resulting in improved computer infrastructure that can easily be restored following a natural disaster and which features fault tolerant hosts/components, isolates applications security attacks, is simpler in design, and is easier to manage. Further, because this technology has been out for a number of years and its capabilities have matured an attempt has been made to describe those capabilities as well as document successful applications. © 2011, IGI Global.
Wen J.,Rutgers University |
Tan R.,Rutgers University |
Liu S.,Rutgers University |
Zhao Q.,Northwest University |
Zhang X.,Rutgers University
Chemical Science | Year: 2016
Rhodium catalyzed asymmetric hydrogenation of both isoquinolines and quinolines provides a new method to synthesize chiral tetrahydroisoquinolines and tetrahydroquinolines. By introducing strong Brønsted acid HCl, anion binding between the substrate and the ligand was established to achieve high reactivity and high enantioselectivity (up to 99% conversion and 99% ee). An NMR study suggests an anion binding between the catalyst and the substrate. Deuterium labeling experiments reveal a plausible reaction pathway. © 2016 The Royal Society of Chemistry.
Liu X.,Northwest University |
Qiu W.S.,Northwest University
IEEE Transactions on Reliability | Year: 2011
This paper presents a method for planning multiple-step step-stress ALT (SSALT) with statistically independent competing risks. A statistical model is constructed and asymptotically c-, D-, and Ds-optimal ALT plans are developed. Because the asymptotical optimality might sometimes lead to impractical ALT plans with finite sample size, additional constraints are introduced, and the planning of ALT on the constrained design space is also studied. Finally, we provide a numerical example to illustrate the application of the proposed method. © 2011 IEEE.
Ma J.,Northwest University |
Jing G.,Northwest University |
Jing G.,NanoBiophotonics Center
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2012
The fracture mechanics was usually employed to explain the crack propagation in the deposition produced by drying colloidal suspension. However, more complex than conventional fracture, those cracks periodically distribute and make up a unique pattern. Inspired by the concept of spinodal decomposition, here we develop the theory to illustrate the possible mechanism of the spatial arrangement of the cracks. It indicates that before the cracks develop and propagate in the deposition under the law of fracture mechanics, the periodically distributed flaws are generated by the phase separation of colloidal clusters and solvent. Then the cracks originate at the sites of those flaws in terms of fracture mechanics. It concludes that the crack spacing results from the wavelength of the concentration fluctuation during the phase separation, linearly growing with the increase of the deposition thickness and initial particle concentration, which is consistent with experimental results. © 2012 American Physical Society.
G. pannuceum (from the Latin word "pannuceus," meaning "wrinkled") gets its name from the wrinkled sheath covering its midbody. Four species of parasitoid wasps have been discovered in northwest China, a new study reports. The new species belong to the genus Gasteruption. These wasps have slender bodies and inflated, club-shaped hind legs. They also have elongated necks, and keep their abdomens raised and hind legs dangling during their slow, quiet flights. Their heads have a satin-like sheen and long eyes that extend almost to their mouth, the researchers said. The four new species — G. bicoloratum, G. huangshii, G. pannuceum and G. shengi — have a body covering that resembles black leather with grooves and stitches. The bugs range in size from 0.3 inches (8 millimeters) long to 0.5 inches (13 mm) long, and females are typically larger than males. [Googly Eyes: Photos of Striking Wasp Faces] The newfound species are parasitoid wasps whose larvae are parasites that kill their hosts. Adults hover outside the nests of solitary bees. While females hover to find an opportunity to sneak their own eggs into solitary bee nests, males typically linger in search of these females. Using a long, tube-like organ, called an ovipositor, the female lays eggs inside bee nests. The emerging larvae feed on bee eggs and larvae, and the food reserves of the nest. The young wasps pupate in their hosts' nests and emerge as adults in spring. The adult wasps can be locally abundant at times, particularly when they are feeding on pollen and nectar at flowers, said Jiang-Li Tan, an entomologist in the College of Life Sciences at Northwest University in China. But, "they are not encountered frequently and, in many regions of the world, are rarely collected," she said. A total of 28 species of Gasteruption were known from China before the new finds. Tan's team discovered four new species in the mountainous region of China's Shaanxi and Ningxia provinces. Tan lives near the Qinling mountains in Shaanxi, and every weekend during spring and summer, she would drive there with her students to sample wasps. "I am not surprised to find four new species," Tan told Live Science in an email. She added that there are likely more wasp species waiting to be found. But, it is not easy to identify a new species, Tan said. A combination of characteristics such as the shape of the head and legs, length of ovipositor, skin pattern, body color, and wing pattern and color, were used. G. bicoloratum was found at an elevation of around 3,600 feet (1,100 meters) above sea level. The species gets its name from its bicoloured hind legs, which are ivory and yellowish-brown. At 0.05 inches (1.2 mm) long, the ovipositor of females is very short, the scientists note in the paper. [No Creepy Crawlies Here: Gallery of the Cutest Bugs] G. huangshii was named after Huang Shi Gong — believed to be a teacher of a Han Dynasty general — since the wasp was found near his statue. It was found at an elevation of 4,400 feet (1,350 m) above sea level. In females of this species, the ovipositor is very long, about 1.2 times the length of the body, the study finds. G. pannuceum (from the Latin word "pannuceus," meaning "wrinkled") gets its name from the wrinkled sheath covering its midbody. And, G. shengi was named after its collector, Mao-Ling Sheng, in recognition of his work on parasitoid wasps of China. The largest of the four new species, G. shengi wasps are covered in dense, silvery hair, the researchers wrote in the study. The findings were published online Aug. 23 in the journal ZooKeys. Copyright 2016 LiveScience, a Purch company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.