We develop a GARCH option model with a variance premium by combining the HestonNandi (2000) dynamic with a new pricing kernel. While the pricing kernel is monotonic in the stock return and in variance, its projection onto the stock return is nonmonotonic. A negative variance premium makes it appear U-shaped. We present new semi-parametric evidence to confirm this U-shaped relationship between t...

Abst ract . The efficiency of A* searching depends on the quality of the lower bound estimates of the solution cost. Pattern databases enumerate all possible subgoals required by any solution, subject to constraints on the subgoal size. Each subgoal in the database provides a tight lower bound on the cost of achieving it. For a given state in the search space, all possible subgoals are looked u...

AIMS To establish the minimum dimensions for a non-precious cast metal occlusal rest by using mathematical analysis. An occlusal rest in a removable partial denture (RPD) provides vertical support and allows occlusal forces to be transmitted through the long axis of the abutment tooth. METHODS The stress status of an occlusal rest in a posterior tooth-bounded RPD resembles that of a cantileve...

We consider the parameterized complexity of a generalized version of the game Rush Hour , which is a puzzle requiring the player to find a sequence of moves by vehicles to enable a special target vehicle to escape from a grid-shaped game board that may contain obstacles. Although the problem is PSPACE-complete, we demonstrate algorithms that work in polynomial time when either the total number ...

OBJECTIVE To evaluate the effects of recasting on the biocompatibility of a commercially available Ni-Cr alloy. METHODS The alloy tested was cast and subsequently recast four more times. For each cast condition, 24 disk shaped specimens were fabricated (5 mm in diameter, 0.5 mm in thickness). All the recasting was performed without adding new alloy. After the first cast and following each rec...

Cast nickel aluminum bronze (NAB) alloy is widely used for large engineering components in marine applications due to its excellent mechanical properties and corrosion resistance. Casting porosity, as well as coarse microstructure, however, are accompanied by a decrease in mechanical properties of cast NAB components. Although heat treatment, friction stir processing, and fusion welding were im...

The rapid collapse of a polymer, due to external forces or changes in solvent, yields a long-lived "crumpled globule." The conjectured fractal structure shaped by hierarchical collapse dynamics has proved difficult to establish, even with large simulations. To unravel this puzzle, we study a coarse-grained model of in-falling spherical blobs that coalesce upon contact. Distances between pairs o...

Jigsaw puzzles [9] and edge-matching puzzles [5] are two ancient types of puzzle, going back to the 1760s and 1890s, respectively. Jigsaw puzzles involve fitting together a given set of pieces (usually via translation and rotation) into a desired shape (usually a rectangle), often revealing a known image or pattern. The pieces are typically squares with a pocket cut out of or a tab attached to ...

The rapid collapse of a polymer, due to external forces or changes in solvent, yields a long-lived ‘crumpled globule.’ The conjectured fractal structure shaped by hierarchical collapse dynamics has proved difficult to establish, even with large simulations. To unravel this puzzle, we study a coarse-grained model of in-falling spherical blobs that coalesce upon contact. Distances between pairs o...