I study the dynamic mechanism design problem of a monopolist selling a fixed number of service slots to randomly arriving, short-lived buyers with heterogeneous values. The fully optimal mechanism is a non-standard auction in which bidders’ payoffs are non-monotone in their opponents’ bids. Because its complexity may make the fully optimal mechanism too costly to implement, I also study the opt...

Complex temporal expressions are widely used in daily life. A calendars is one of the important examples for this kind of expressions. In this paper, we study the query language on general calendars. A set of operators for calendar algebra is formed. Several formulas are put forward for the purpose of query optimization. Other properties including monotonicity, closure and uniqueness of operato...

Climate change  is one of the most important challenges in recent years. Heavy flood, hot weather, early coldness, most of drought replications, risen of sea water level, pests and plant disease ,reducing of ozone layer thickness, global worming ,and melting ices, are cases that introduced climate change issue in recent decades more. Climate is one of the most important  factors for crop  chang...