Ka Chun Cheung

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Despite scientific and clinical advances in the field of pharmacogenomics (PGx), application into routine care remains limited. Opportunely, several implementation studies and programs have been initiated over recent years. This article presents an overview of these studies and identifies current research gaps. Importantly, one such gap is the undetermined(More)
We revisit the problem of minimizing a separable convex function with a linear constraint and box constraints. This optimization problem arises naturally in many applications in economics, finance and insurance. Existing literature exclusively tackles this problem by using the traditional Kuhn-Tucker theory, which leads to either iterative schemes or yields(More)
In this paper, we study the problems of optimal allocation of policy limits and de-ductibles. Several objective functions are considered: maximizing the expected utility of wealth assuming the losses are independent, minimizing the expected total retained loss, and maximizing the expected utility of wealth when the dependence structure is unknown. Orderings(More)
In this article, we show that some important implications concerning comonotonic couples and corresponding convex order relations for their sums cannot be translated to counter-monotonicity in general. In a financial context, it amounts to saying that merging counter-monotonic positions does not necessarily reduce the overall level of risk. We propose a(More)
This article investigates optimal reinsurance treaties minimizing an insurer’s riskadjusted liability, which encompasses a risk margin quantified by distortion risk measures. Via the introduction of a transparent cost-benefit argument, we extend the results in Cui et al. [Cui, W., Yang, J., Wu, L., 2013. Optimal reinsurance minimizing the distortion risk(More)
This paper analyzes the investment-consumption problem of a risk averse investor in discrete-time model. We assume that the return of a risky asset depends on the economic environments and that the economic environments are ranked and described using a Markov chain with an absorbing state which represents the bankruptcy state. We formulate the investor's(More)