Wild hypersurfaces

Complete hypersurfaces of dimension at least 2 and multiplicity at least 4 have wild Cohen-Macaulay type.Comment: 16 pages. v2 incorporates referee's suggested revisions; to appear in JPA

Optimising Broadacre Crop Rotations using Dynamic Programming

A Dynamic programming Model is used to select the most profitable crop rotation from seven crop alternatives including pasture. Crop yields within a rotation are estimated by specifying growing season rainfall, water use efficiency and weed and disease penalties caused by the three previous years crop history. A provision exists to include the effect on yield of other natural resource limitations. Regional variations can be accounted for by varying rainfall, management practices, yield penalties and input costs. A nitrogen-phosphorous calculator ensures sufficient fertiliser is applied for the crop to achieve its expected yield. This approach can be used to measure the productivity implications of advances in technology as well as the impact of rainfall, yield and price variations on optimal rotations.Crop Production/Industries,

Interrupting the Response of \u3ci\u3eDendroctonus Simplex\u3c/i\u3e Leconte (Coleoptera: Curculionidae: Scolytinae) to Compounds That Elicit Aggregation of Adults

The eastern larch beetle, Dendroctonus simplex LeConte (Coleoptera: Curculionidae: Scolytinae), is a native bark beetle that has caused significant mortality to tamarack, Larix laricinia, in the Upper Peninsula of Michigan. The effectiveness of potentially attractive chemicals for D. simplex was tested and the most attractive compound, seudenol, was used in subsequent studies to test interruptants against D. simplex. Verbenone, methylcyclohexenone (MCH), and 4-allylanisole were tested as potential interruptants in combination with seudenol. Catches of D. simplex in traps baited with seudenol and MCH were not significantly different from catches in unbaited control traps, indicating successful interruption of the response to seudenol by MCH. Verbenone released at commercially available doses significantly increased catches of D. simplex in traps baited with seudenol, however it did not catch significantly more D. simplex than the unbaited control traps when released alone. Traps baited with 4-allylanisole did not significantly reduce the number of D. simplex captured compared to traps baited solely with seudenol. The potential for MCH to be used to protect individual trees and in stand level management of D. simplex is discussed

Centres of Hecke algebras: the Dipper-James conjecture

In this paper we prove the Dipper-James conjecture that the centre of the Iwahori-Hecke algebra of type A is the set of symmetric polynomials in the Jucys-Murphy operators.Comment: 27 pages. To appear J. Algebr

A Framework for Constraint-Based Deployment and Autonomic Management of Distributed Applications

We propose a framework for deployment and subsequent autonomic management of component-based distributed applications. An initial deployment goal is specified using a declarative constraint language, expressing constraints over aspects such as component-host mappings and component interconnection topology. A constraint solver is used to find a configuration that satisfies the goal, and the configuration is deployed automatically. The deployed application is instrumented to allow subsequent autonomic management. If, during execution, the manager detects that the original goal is no longer being met, the satisfy/deploy process can be repeated automatically in order to generate a revised deployment that does meet the goal.Comment: Submitted to ICAC-0

A Middleware Framework for Constraint-Based Deployment and Autonomic Management of Distributed Applications

We propose a middleware framework for deployment and subsequent autonomic management of component-based distributed applications. An initial deployment goal is specified using a declarative constraint language, expressing constraints over aspects such as component-host mappings and component interconnection topology. A constraint solver is used to find a configuration that satisfies the goal, and the configuration is deployed automatically. The deployed application is instrumented to allow subsequent autonomic management. If, during execution, the manager detects that the original goal is no longer being met, the satisfy/deploy process can be repeated automatically in order to generate a revised deployment that does meet the goal.Comment: Submitted to Middleware 0

Long-term concentration of measure and cut-off

We present new concentration of measure inequalities for Markov chains that enjoy a contractive property. We apply our discrete-time inequality to the well-studied Bernoulli-Laplace model of diffusion, and give a probabilistic proof of cut-off, recovering the optimal bounds of Diaconis and Shahshahani. We also extend the notion of cut-off to chains with an infinite state space, and illustrate this in a second example, of a two-host model of disease in continuous time.Comment: 36 page

Applying constraint solving to the management of distributed applications

Submitted to DOA08We present our approach for deploying and managing distributed component-based applications. A Desired State Description (DSD), written in a high-level declarative language, specifies requirements for a distributed application. Our infrastructure accepts a DSD as input, and from it automatically configures and deploys the distributed application. Subsequent violations of the original requirements are detected and, where possible, automatically rectified by reconfiguration and redeployment of the necessary application components. A constraint solving tool is used to plan deployments that meet the application requirements.Postprin