نتایج جستجو برای: observational astronomy

تعداد نتایج: 117029  

2015
Peter C. Austin Elizabeth A. Stuart

The propensity score is defined as a subject's probability of treatment selection, conditional on observed baseline covariates. Weighting subjects by the inverse probability of treatment received creates a synthetic sample in which treatment assignment is independent of measured baseline covariates. Inverse probability of treatment weighting (IPTW) using the propensity score allows one to obtai...

2015
Seunghee Baek Seong Ho Park Eugene Won Yu Rang Park Hwa Jung Kim

The propensity score is defined as the probability of each individual study subject being assigned to a group of interest for comparison purposes. Propensity score adjustment is a method of ensuring an even distribution of confounders between groups, thereby increasing between group comparability. Propensity score analysis is therefore an increasingly applied statistical method in observational...

2006
Nina Bohr Lars Birkedal

We present a local relational reasoning method for reasoning about contextual equivalence of expressions in a λ-calculus with recursive types and general references. Our development builds on the work of Benton and Leperchey, who devised a nominal semantics and a local relational reasoning method for a language with simple types and simple references. Their method uses a parameterized logical r...

Journal: :Journal of applied behavior analysis 2011
Jessica Singer-Dudek Mara Oblak R Douglas Greer

We tested the effects of an observational intervention (Greer & Singer-Dudek, 2008) on establishing children's books as conditioned reinforcers using a delayed multiple baseline design. Three preschool students with mild language and developmental delays served as the participants. Prior to the intervention, books did not function as reinforcers for any of the participants. The observational in...

Journal: :Value in health : the journal of the International Society for Pharmacoeconomics and Outcomes Research 2014
J Alsop

The current tendency is to provide post-approval evidence from separate, often larger and less well controlled trials. Typical examples of these are pragmatic trials (randomisation, little/no control), purely prospective observational trials (no randomisation, no control) and use of historic controls. #3 New study design: Mixed RCT (cont.) In a Mixed RCT patients would be selected and randomise...

Journal: :Astronomy and Astrophysics 2023

Catalogs with celestial positions and uncertainties are among the primary data products of observational astronomy. Consequently, (cross-)matching problem, namely, question how many (and which) pairs pertain to same source, remains a central part this scientific exploitation. We address matching problem for two catalogs from purely geometric point view by adopting concept processes nearest-neig...

1997
David H. Weinberg Jordi Miralda-Escudé Lars Hernquist Neal Katz

We derive lower bounds on the cosmic baryon density from the requirement that the high-redshift intergalactic medium (IGM) contain enough neutral hydrogen to produce the observed Lyα absorption in quasar spectra. The key theoretical assumption that leads to these analytic bounds is that absorbing structures are no more extended in redshift space than they are in real space. This assumption migh...

2009
Andrei Tokovinin

Current and future techniques relevant to binary-star observations are reviewed. Binary-star science is not driving present and future instrumentation, but does benefit from it. Data mining opens new perspectives. Increased data flow and sample sizes call for a new approach to maintaining the catalogs, which otherwise will collapse. We discuss high-resolution and high-contrast imaging with adap...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید