3,821 research outputs found
Requirements for multidisciplinary design of aerospace vehicles on high performance computers
The design of aerospace vehicles is becoming increasingly complex as the various contributing disciplines and physical components become more tightly coupled. This coupling leads to computational problems that will be tractable only if significant advances in high performance computing systems are made. Some of the modeling, algorithmic and software requirements generated by the design problem are discussed
Wealth effects and Russian money demand
We examine wealth effects for Russian money demand in a cointegrated vector autoregressive framework. We find that an aggregate wealth variable, as well as the components housing and equity prices included separately, significantly enter the long-run money demand relationship. There are feedback effects from money to wealth. However, the remonetization process lead to high income elasticities even when wealth is included in the model. System instability coincides with the arrival of the global financial crisis in late 2008.money demand; wealth effects; financial crisis; Russia
Towards Evaluating the Quality of a Spreadsheet: The Case of the Analytical Spreadsheet Model
We consider the challenge of creating guidelines to evaluate the quality of a
spreadsheet model. We suggest four principles. First, state the domain-the
spreadsheets to which the guidelines apply. Second, distinguish between the
process by which a spreadsheet is constructed from the resulting spreadsheet
artifact. Third, guidelines should be written in terms of the artifact,
independent of the process. Fourth, the meaning of "quality" must be defined.
We illustrate these principles with an example. We define the domain of
"analytical spreadsheet models", which are used in business, finance,
engineering, and science. We propose for discussion a framework and terminology
for evaluating the quality of analytical spreadsheet models. This framework
categorizes and generalizes the findings of previous work on the more narrow
domain of financial spreadsheet models. We suggest that the ultimate goal is a
set of guidelines for an evaluator, and a checklist for a developer.Comment: Proc. European Spreadsheet Risks Int. Grp. (EuSpRIG) 2011 ISBN
978-0-9566256-9-
Calcium channel Orai1 promotes lymphocyte IL-17 expression and progressive kidney injury
We hypothesized that the store-operated calcium entry (SOCE) channel, Orai1, participates in the activation of Th17 cells and influences renal injury. In rats, following renal ischemia/reperfusion (I/R), there was a rapid and sustained influx of Orai1+ CD4 T cells and IL-17 expression was restricted to Orai1+ cells. When kidney CD4+ cells of post-acute kidney injury (post-AKI) rats were stimulated with angiotensin II and elevated Na+ (10-7 M/170 mM) in vitro, there was an enhanced response in intracellular Ca2+ and IL-17 expression, which was blocked by SOCE inhibitors 2APB, YM58483/BTP2, or AnCoA4. In vivo, YM58483/BTP2 (1 mg/kg) attenuated IL-17+ cell activation, inflammation, and severity of AKI following either I/R or intramuscular glycerol injection. Rats treated with high-salt diet (5-9 weeks after I/R) manifested progressive disease indicated by enhanced inflammation, fibrosis, and impaired renal function. These responses were significantly attenuated by YM58483/BTP2. In peripheral blood of critically ill patients, Orai1+ cells were significantly elevated by approximately 10-fold and Th17 cells were elevated by approximately 4-fold in AKI versus non-AKI patients. Further, in vitro stimulation of CD4+ cells from AKI patients increased IL-17, which was blocked by SOCE inhibitors. These data suggest that Orai1 SOCE is a potential therapeutic target in AKI and CKD progression
Collision-free motion of two robot arms in a common workspace
Collision-free motion of two robot arms in a common workspace is investigated. A collision-free motion is obtained by detecting collisions along the preplanned trajectories using a sphere model for the wrist of each robot and then modifying the paths and/or trajectories of one or both robots to avoid the collision. Detecting and avoiding collisions are based on the premise that: preplanned trajectories of the robots follow a straight line; collisions are restricted to between the wrists of the two robots (which corresponds to the upper three links of PUMA manipulators); and collisions never occur between the beginning points or end points on the straight line paths. The collision detection algorithm is described and some approaches to collision avoidance are discussed
<i>Aporosa</i> Blume from the paleoequatorial rainforest of Bikaner, India: Its evolution and diversification in deep time
The Gondwanan origin, northward migration and subsequent collision with Asia means that the Indian subcontinent is of particular interest regarding the origin and dispersal of numerous plants and animal species. With this in mind, we describe a fossil leaf of Aporosa Blume (Phyllanthaceae) from the Paleogene of the Indian subcontinent and discuss its evolution and diversification with respect to the moving Indian plate and its connection with Southeast Asia since the early Cenozoic. At present, Aporosa Blume is confined to Southeast Asia with a few species in India and New Guinea. It is represented by six endemic species growing in the evergreen forests of India and Sri Lanka, including Aporosa acuminata Thwaites, which is morphologically close to the here described fossil from Bikaner, Rajasthan, India. From the age of the fossil and the distribution of its modern comparable form, it is assumed that Aporosa originated on the Indian subcontinent and then was distributed to Southeast Asia, supporting the ‘Out of India’ hypothesis. Diversification of the genus might have taken place either in the Paleogene or Neogene. Our fossil leaf material also indicates the existence of palaeoequatorial (< 10° N) tropical rain forests in western India during the Paleogene in contrast to dry and desertic climate occurring today
Modelling inflation in China - a regional perspective
We model provincial inflation in China during the reform period. In particular, we are interested in the ability of the hybrid New Keynesian Phillips Curve (NKPC) to capture the inflation process at the provincial level. The study highlights differences in inflation formation and shows that the NKPC provides a reasonable description of the inflation process only for the coastal provinces. A probit analysis suggests that the forwardlooking inflation component and the output gap are important inflation drivers in provinces that have advanced most in marketisation of the economy and have most likely experienced excess demand pressures. These results have implications for the relative effectiveness of monetary policy across the Chinese provinces. JEL Classification: E31, C22China, GMM, inflation, New Keynesian Phillips curve, Regional
La performance des infrastructures vertes de gestion des eaux pluviales dans la ville de New York
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