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Wan W.,Resource Data
Proceedings of the International Astronautical Congress, IAC | Year: 2013

China's satellite observation system and its massive image information can contribute to the construction of Spatial Information Infrastructures system in the future. The increasing amount of incoming satellite data and increases in the on-demand processing/reprocessing for massive data products are causing an excessive load on the conventional systems. And for service, changes to the current architectures may be necessary to continue providing services efficiently to users. Cloud computing emerges as a new computing paradigm which aims to provide dynamic computing environments for storing and processing very large datasets, and provide users various resources as services. In this paper we analyzed the status and features of the traditional satellite data systems. In order to build "dynamic" cloud data center as the goal, we design the new architecture that enables the Cloud of virtualized resources for providing on-demand processing and archiving services. We introduced a high level application services framework and the underlying technology enablers, such as the resource pools, dynamic expansion, elastic computing, load management, remote sensing workflow engine and so on. The selection of technical approaches is analyzed. This work is an initial effort to build satellite data center based on Cloud, and also represents the evolution from the traditional system to the next generation satellite data center for spatial information infrastructure in the future. Copyright © 2013 by the International Astronautical Federation. ©2013 by the International Astronautical Federation. All rights reserved. Source


Wei X.-G.,Beihang University | Wang Q.-L.,Beihang University | Li J.,Beihang University | He H.-Y.,Resource Data
Guangxue Jingmi Gongcheng/Optics and Precision Engineering | Year: 2013

A calibration method for the cross-angle between the optical axis of a remote sensing camera and that of a star sensor was investigated to improve the positioning accuracy of remote sensing images. On the basis of the rigorous space resection model, the unified calibration method of interior and exterior orientation elements was proposed by introducing an improved non-direction solving model into the calibration of mounting error of the remote sensing camera. By which, the system error between attitude determining sensor and remote sensing camera was compensated accurately. In processing the remote sensing images from a satellite, the relationship matrix between remote sensing camera and star sensor attitude were determined by the optimized model, then the cross-angle was calibrated accurately. Finally, the cross-angle model was verified with the geometrical relationship of single-image targeting. After the calibration, the plane position RMS errors are 9.31 m and 9.28 m in latitude and longitude directions, respectively, which shows that the positioning accuracy of the remote sensing images have been improved greatly by the proposed method. Source


Wagner M.,Tufts Medical Center | Wagner M.,University Hospital Wrzburg | Ansell D.,UK Renal Registry | Kent D.M.,Center for Predictive Medicine Research | And 4 more authors.
American Journal of Kidney Diseases | Year: 2011

Background: The risk of death in dialysis patients is high, but varies significantly among patients. No prediction tool is used widely in current clinical practice. We aimed to predict long-term mortality in incident dialysis patients using easily obtainable variables. Study Design: Prospective nationwide multicenter cohort study in the United Kingdom (UK Renal Registry); models were developed using Cox proportional hazards. Setting & Participants: Patients initiating hemodialysis or peritoneal dialysis therapy in 2002-2004 who survived at least 3 months on dialysis treatment were followed up for 3 years. Analyses were restricted to participants for whom information for comorbid conditions and laboratory measurements were available (n = 5,447). The data set was divided into data sets for model development (n = 3,631; training) and validation (n = 1,816) using random selection. Predictors: Basic patient characteristics, comorbid conditions, and laboratory variables. Outcomes: All-cause mortality censored for kidney transplant, recovery of kidney function, and loss to follow-up. Results: In the training data set, 1,078 patients (29.7%) died within the observation period. The final model for the training data set included patient characteristics (age, race, primary kidney disease, and treatment modality), comorbid conditions (diabetes, history of cardiovascular disease, and smoking), and laboratory variables (hemoglobin, serum albumin, creatinine, and calcium levels); reached a C statistic of 0.75 (95% CI, 0.73-0.77); and could discriminate accurately among patients with low (6%), intermediate (19%), high (33%), and very high (59%) mortality risk. The model was applied further to the validation data set and achieved a C statistic of 0.73 (95% CI, 0.71-0.76). Limitations: Number of missing comorbidity data and lack of an external validation data set. Conclusions: Basic patient characteristics, comorbid conditions, and laboratory variables can predict 3-year mortality in incident dialysis patients with sufficient accuracy. Identification of subgroups of patients according to mortality risk can guide future research and subsequently target treatment decisions in individual patients. © 2011 National Kidney Foundation, Inc. Source


Harish M.,Resource Data
Rasayan Journal of Chemistry | Year: 2010

For the long history the irrigation is the foremost important for agriculture in rural areas. This paper discuses the situation in which knowledge of community irrigation systems, useful for policy makers for the welfare of the people in the district. While the instance of national policy that includes the development of new small scale irrigation systems. Today the Chamarajanagr economy is facing a severe crisis on water for irrigational land use and imbalance in water supply among the water users. Some of the reasons for the crisis are that there is a river flow in the district where low rainfall and failure in planning. Using rain water as a resource for micro level planning of water bodies as alternative use of irrigation in the village levels, instead of depending on irrigational projects is required for sustainability in irrigation. © 2010 RASĀYAN. All rights reserved. Source


Tangri N.,Tufts Medical Center | Wagner M.,Tufts Medical Center | Griffith J.L.,Resource Data | Miskulin D.C.,Tufts Medical Center | And 3 more authors.
American Journal of Kidney Diseases | Year: 2011

Background: Abnormalities in bone mineral metabolism parameters are common in patients with end-stage kidney disease on dialysis therapy. The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) guidelines propose targets for calcium, phosphate, and intact parathyroid hormone (iPTH) levels in patients undergoing dialysis. However, whether achievement of these targets improves survival is unknown. Study Design: Retrospective cohort study. Setting & Participants: Incident patients on hemodialysis or peritoneal dialysis therapy in the United Kingdom from 2000-2004 who survived at least 12 months. Predictor: Achievement of KDOQI calcium, phosphate, and iPTH guideline targets during the first year of dialysis therapy. Outcomes: All-cause mortality in the subsequent 2 years. Measurements: Calcium, phosphate, and iPTH at quarterly intervals, demographic and comorbid condition data at baseline. Results: We included 7,076 incident patients (4,947 hemodialysis, 2,129 peritoneal dialysis) in our analysis. Approximately two thirds of patients were men and 21% had diabetes as the cause of kidney failure. Guideline target achievement for each quarter varied from 23%-26% for iPTH level, 43%-47% for calcium level, and 54%-62% for phosphate level targets. In adjusted Cox proportional hazards models, patients who achieved guideline targets in all 4 quarters did not have a survival advantage over patients who never achieved target (P > 0.1 for calcium, phosphate, and iPTH). Limitations: Missing information about medication use, vitamin D and alkaline phosphatase levels, and dialysate calcium content. Conclusions: Our findings do not support the use of KDOQI bone mineral guideline achievement as a quality measure for dialysis care. Prospective studies with longer term follow-up are needed to define the optimal cutoff values for calcium, phosphate, and iPTH and assess the effect of guideline implementation on patient survival. © 2011 National Kidney Foundation, Inc. Source

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