Predation directly triggers behavioural decisions designed to increase immediate survival. However, these behavioural modifications can have long term costs. There is therefore a trade-off between antipredator behaviours and other activities. This trade-off is generally considered between vigilance and only one other behaviour, thus neglecting potential compensations. In this study, we consider...

We study the following on-line model for set-covering: elements of a ground set of size n arrive one-by-one and with any such element ci, arrives also the name of some set Si0 containing ci and covering the most of the uncovered ground set-elements (obviously, these elements have not been yet revealed). For this model we analyze a simple greedy algorithm consisting of taking Si0 into the cover,...

Governments often use multiple policy instruments for pursuing policy goals with mutually reinforcing eff ects. Th ese eff ects include supplementation and substitution. Th is article examines both eff ects by studying two instruments of state budget stabilization policy: general fund balances and budget stabilization funds. States normally maintain budget surpluses in the general fund. In rece...

In Situ X-Ray Absorption Spectroscopic Study of Li1.05Ni0.35Co0.25Mn0.4O2 Cathode Material Coated with LiCoO2 Aniruddha Deb, Uwe Bergmann, Stephen P. Cramer, and Elton J. Cairns* Environmental Energy Technologies Division and Physical Bioscience Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA Stanford Synchrotron Radiation Laboratory, Menlo Park, California 9402...

Dynamic Energy Budget theory meets individual-based modelling: a generic and accessible implementation Benjamin T. Martin*, Elke I. Zimmer, Volker Grimm and Tjalling Jager Department of Ecological Modelling, Helmholtz Centre for Environmental Research – UFZ, 04318 Leipzig, Germany; and FALW ⁄Department of Theoretical Biology, Vrije Universiteit Amsterdam, De Boelelaan 1085, NL-1081 HV Amsterdam...

maximizing economic earnings is the most common goal in cut-off grade optimization of open-pit mining operations. when this is the case, the price of the product has a critical effect on optimum value of cut-off grade. this paper investigates the relationship between optimum cut-off grade and price to maximize total cash flow and net percent value (npv) of operation. in order to visualize this ...

Stackelberg games are a classic example of bilevel optimization problems, which are often encountered in game theory and economics. These are complex problems with a hierarchical structure, where one optimization task is nested within the other. Despite a number of studies on handling bilevel optimization problems, these problems still remain a challenging territory, and existing methodologies ...

Department of Systems Engineering and Operations Research George Mason University, Fairfax, VA 22030, USA [email protected] [email protected] Abstract We present a simulation run allocation scheme for improving efficiency in simulation experiments for decision making under uncertainty. This scheme is called Optimal Computing Budget Allocation (OCBA). OCBA advances the state-of-the-art by intelligently ...

 Simulation and optimization are two arguably most used operations research (OR) tools. Optimization intends to choose the best element from some set of available alternatives. Stochastic simulation is a powerful modeling and software tool for analyzing modern complex systems. This capability complements the inherent limitation of traditional optimization, so the combining use of simulation an...