Technical Reports (Mathematics and Statistics)
http://hdl.handle.net/1828/9040
2019-12-05T21:15:04ZUse of closed population models to estimate the number of injection drug users in Victoria, B.C.
http://hdl.handle.net/1828/3361
Use of closed population models to estimate the number of injection drug users in Victoria, B.C.
Xu, Yuan; Cowen, Laura
Closed mark-recapture experiments are widely used to estimate population size even though the assumption of "closed population"' is often violated (immigrations and emigrations) compared to open population models. This work investigates various methods in closed population models (Petersen estimator, maximum likelihood estimation with mixtures, and Huggins model) to estimate the number of injection drug users (IDU) in Victoria, B.C. Model selection methods used to choose a final model as well as goodness-of-fit options are discussed. We use data from the 2003 and 2005's I-Track survey program to compare these estimators.
2011-06-07T00:00:00ZOptimization of multi-drug composition for the most efficacious action
http://hdl.handle.net/1828/2835
Optimization of multi-drug composition for the most efficacious action
Bose, Chris; Bizuet, Rocky; Caudillo, Luz; Gong, Jiafen; Jain, Rashi; Romanko, Oleksandr; Samarbakhsh, Abdi; Tam, Yun K.
In this report we consider a drug-design problem as it typically appears in Chinese medicine, where a large number of potentially active components are combined into one herbal therapy. The problem is posed by the SinoVeda Canada Inc. We focus on techniques for component-activity analysis in order to isolate the most active components, and the most active synergies between components as measured by tissue response to prepared herbal mixtures. The aim is to produce both qualitative and quantitative descriptions of the most active dose-fractions for a given herbal therapy and to aid in optimal design of herbal mixtures treating the target diseases. This report describes various techniques to achieve this goal, including multivariate linear regression, principle component analysis, subset selection and regularization.
2010-06-02T19:53:07ZApproximation by normal elements with finite spectra in simple AF-algebras
http://hdl.handle.net/1828/2828
Approximation by normal elements with finite spectra in simple AF-algebras
Lin, Hauxin
We show that normal elements in simple AF-algebras with countably many extremal traces (such as UHF-algebras and matroid algebras) can be approximated by normal elements with finite spectra. Other AF-algebras are shown to have the same property.
2010-06-01T22:05:39ZNotes on K-theory of multiplier algebras and corona algebras
http://hdl.handle.net/1828/2827
Notes on K-theory of multiplier algebras and corona algebras
Lin, Hauxin
We give an answer to the question when the unitary group of the corona algebra of a simple AF-algebra is connected. We also compute the K-groups of the multiplier algebras and corona algebras of certain simple C*-algebras. For example, if A_\theta is an irrational rotation C*-algebra and A is a non-stable hereditary C*-subalgebra of A_\theta \varotimes K, then we find that K_1(M(A)) = K_1(M(A)/A) = {0} and K_0(M(A)) = R.
2010-06-01T19:48:45Z