Decision-theoretic control of EUVE telescope scheduling

This paper describes a decision theoretic scheduler (DTS) designed to employ state-of-the-art probabilistic inference technology to speed the search for efficient solutions to constraint-satisfaction problems. Our approach involves assessing the performance of heuristic control strategies that are normally hard-coded into scheduling systems and using probabilistic inference to aggregate this information in light of the features of a given problem. The Bayesian Problem-Solver (BPS) introduced a similar approach to solving single agent and adversarial graph search patterns yielding orders-of-magnitude improvement over traditional techniques. Initial efforts suggest that similar improvements will be realizable when applied to typical constraint-satisfaction scheduling problems

Capital Markets, Ownership and Distance

This paper uses a new data-set to examine how internal capital markets and foreign ownership affect investment. Our data allow us to compare investment behaviour of listed subsidiaries with stand-alone firms while controlling for investment opportunities of parent and subsidiary firms. We evaluate how the size of ownership and the geographical proximity of majority owners to their subsidiaries affect firm investment efficiency. We find that the investment of subsidiaries is more sensitive to investment opportunities than that of standalone firms and falls when investment opportunities of parent firms improve. This suggests that there are internal capital markets that reallocate funds towards units with better investment opportunities. We find that investment allocation is most efficient where parents have modest ownership stakes and are distant from their subsidiaries and when subsidiaries operate in well developed financial markets. These results indicate that influence costs imposed by dominant parents may outweigh their potential informational benefits, especially when subsidiaries are located in countries with weaker financial development.Investment, Internal Capital Markets, Foreign Ownership

The Diameter of a Rouquier Block

For my Honors Research Project, I will be researching special properties of Rouquier blocks that represent the partitions of integers. This problem is motivated by ongoing work in representation theory of the symmetric group. For each integer n and each prime p, there is an object called a Rouquier block; this block can be visualized as a collection of points in a plane, each corresponding to a partition. In this group of points, we say a pair of points is “connected” if certain conditions on the partitions are met. We compare each partition with each other partition, add edges when we can, and we end up with a collection of points that are connected by some number of edges (note that two points are not connected by a line if the conditions are not met). In my project, I will be finding a formula that will restrict the diameter of this graph. I want to minimize the distance between the two points that are the furthest away from each other. A formula to give the most efficient path is either impossible to find or is too complicated to be useful; rather, I will set a ceiling on this distance, so that, given any two blocks, I can give the largest “most efficient” path length possible

A comparison of two computer graphic systems

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Local Dosing in a 3-Mercaptopropionic Acid Chemically-Induced Epileptic Seizure Model with Microdialysis Sampling

The focus of this research was the development of an animal model for local administration of 3-mercaptopropionic acid (3-MPA) in a chemically-induced epileptic seizure model using microdialysis sampling with simultaneous electrocorticography recording (ECoG). Local administration of 3-MPA through the microdialysis probe was employed to elicit seizures in a localized brain region. Delivery of 3-MPA to the brain and changes in amino acid and catecholamine neurotransmitters were monitored. Simultaneous ECoG recordings were made using a microdialysis probe with an internal Ag/AgCl electrode. Local administration of a convulsant is important, as many clinical cases present with focal seizures. Neurochemical and electrical activity were monitored in three separate brain regions: the striatum, hippocampus, and locus coeruleus. 3-MPA was administered through the microdialysis probe in one region, while control samples were collected in the other two. These results demonstrated that unless two brain regions were connected via efferent or afferent pathways, administration of 3-MPA in one region had no neurochemical effect in the others. In the region where 3-MPA was administered, an increase in both glutamate, the main excitatory amino acid, and GABA, the main inhibitory amino acid, was seen. In addition, an increase in both dopamine and norepinephrine was seen. A multiple dosing regimen of 3-MPA was developed where 3-MPA was administered twice. These results showed that there was an attenuation in the increase of glutamate and GABA during the second administration of 3-MPA, indicating a neuronal protective mechanism taking place to decrease the effect of the second 3-MPA administration. Seizures were not detected using during local administration of 3-MPA using the microdialysis probes with an internal Ag/AgCl electrode. This was not due to the ineffectiveness of the electrodes, as they detected seizures during systemic dosing of 3-MPA. It is possible that the number of neurons excited from the local administration of 3-MPA were so limited that the signal was too small to be detected

Self-interacting Dark Matter and Invisibly Decaying Higgs

Self-interacting dark matter has been suggested in order to overcome the difficulties of the Cold Dark Matter model on galactic scales. We argue that a scalar gauge singlet coupled to the Higgs boson, which could lead to an invisibly decaying Higgs, is an interesting candidate for this self-interacting dark matter particle. We also present estimates on the abundance of these particles today as well as consequences to non-Newtonian forces.Comment: 4 pages, Revte