RAND Corporation

About: RAND Corporation is a nonprofit organization based out in Santa Monica, California, United States. It is known for research contribution in the topics: Population & Health care. The organization has 9602 authors who have published 18570 publications receiving 744658 citations.

The output properties of Volterra systems (nonlinear systems with memory) driven by harmonic and Gaussian inputs

Abstract: Troublesome distortions often occur in communication systems. For a wide class of systems such distortions can be computed with the help of Volterra series. Results, both old and new, which will aid the reader in applying Volterra-series-type analyses to systems driven by sine waves or Gaussian noise are presented. The n-fold Fourier transform G n of the nth Volterra kernel plays an important role in the analysis. Methods of computing G n from the system equations are described and several special systems are considered. When the G n are known, items of interest regarding the output can be obtained by substituting the G n in general formulas derived from the Volterra series representation. These items include expressions for the output harmonics, when the input is the sum of two or three sine waves, and the power spectrum and various moments, when the input is Gaussian. Special attention is paid to the case in which the Volterra series consists of only the linear and quadratic terms.

Comparative Effectiveness of Treatments To Prevent Fractures in Men and Women With Low Bone Density or Osteoporosis

Abstract: This Comparative Effectiveness Review (CER) compares the benefits in fracture reduction and the harms from adverse events (AE) among and within the various classes of treatment for low bone density. Our outcomes of interest for measuring benefits are vertebral, non-vertebral, hip, and radial fractures. The studies collect vertebral fracture outcomes in one of two ways. In some studies, all participants undergo radiography at pre-determined intervals. Other studies use clinical criteria, i.e. whether a fracture has been diagnosed by a clinician during the time interval. Trials that radiograph all participants will by nature detect more fractures. However the higher detection rate will apply to both treatment and placebo groups. Thus, the relative differences found should be similar that found in studies that use clinical criteria.

Systematic Review: Comparative Effectiveness of Treatments to Prevent Fractures in Men and Women with Low Bone Density or Osteoporosis

Abstract: This systematic review of 76 randomized trials and 24 meta-analyses found good evidence that several agents, including alendronate, zoledronic acid, and estrogen, reduced the risk for vertebral and...