Fractional Differential Equations

Object-oriented analysis

Harmonic Analysis and the Theory of Probability. By S. Bochner pp. 176. 35s. 1955. (California University Press and Cambridge University Press)

Advective flows rapidly transport water, solutes, and particles into and out of permeable sand beds and significantly affects the biogeochemistry of coastal environments. In this paper, we reviewed the drivers of porewater and groundwater advection in permeable shelf sediments in an attempt to bridge gaps among different disciplines studying similar problems. We identified the following driving forces: (1) terrestrial hydraulic gradients, (2) seasonal changes in the aquifer level on land moving the location of the subterranean estuary, (3) wave setup and tidal pumping, (4) water level differences across permeable barriers, (5) flow- and topography-induced pressure gradients, (6) wave pumping; (7) ripple and other bed form migration, (8) fluid shear, (9) density-driven convection, (10) bioirrigation and bioturbation, (11) gas bubble upwelling, and (12) sediment compaction. While these drivers occur over spatial scales ranging from mm to km, and temporal scales ranging from seconds to years, their ultimate biogeochemical implications are very similar (i.e., they are often a source of new or recycled nutrients to seawater and transform organic carbon into inorganic carbon). Drivers 2–12 result in no net water input into the ocean. Taking all these mechanisms into account, we conservatively estimate that a volume equivalent to that of the entire ocean is filtered by permeable sediments at time scales of about 3000 years. Quantifying the relative contribution of these drivers is essential to understand the contribution of sediments to the global cycles of matter.

The driving forces of porewater and groundwater flow in permeable coastal sediments: a review

Glutamine utilization by the small intestine.

Shill bidding is the act of using bids in an online auction to drive up the final price for the seller, thereby
defrauding legitimate bidders. While 'shilling' is recognized as a problem and shill bidding is strictly
forbidden in online auctions, presently there is little to no established means of defense against shills. This paper presents a software bidding agent that follows a shill bidding strategy. The agent incrementally increases an auction's price, forcing legitimate bidders to submit higher bids in order to win the item. The agent ceases bidding when the desired profit from shilling has been attained, or in the case that it is too risky to continue bidding without winning the auction. Its ability to inflate the price has been tested in a simulated marketplace and experimental results are presented. Furthermore, the agent is used to assist in developing algorithms to detect the presence of shill bidding in online auctions.

Online auction deception using a shill bidding agent

Online auctions are a rapidly growing platform to exchange items of just about anything, from common to collectors’ items in different region around the world. Researchers continue their efforts to understand further the real behaviour and bidding patterns of buyers and sellers, the fraudulent traits and even devise countermeasures to prevent auction fraud. Most often, the researchers’ noble work ends with frustration due to unavailability of real auction data. Online auction sources are unwilling to provide the real auction data and often cite “commercial, security and privacy” as reasons. This paper presents a software agent that collects real auction data from an ongoing auction for a given criteria, and automatically returns later to collect the data from a recently completed auction. From the knowledge of the authors, the work presented here is the first serious attempt to create an openly available software tool that will be free for use by other researchers.

A Software Agent for Collecting Real Auction Data from English Online Auctions

In silico experiments use computers or computer simulation to speed up the rate at which scientific discoveries are made. However, the voluminous amounts of data generated in such experiments is often recorded in an ad hoc manner without regard to workflow, and often lacks rigorous business rules. The absence of stringent auditing and reporting policies makes it difficult to repeat experiments and largely denies independent parties the ability to verify study results. This paper presents a data provenance management system based on the utility of the ICAT metadata storage service as a viable schema for representing in silico experiments. The system provides a portal interface to integrate ICAT with job execution. We have built on a data repository which can handle arbitrary data size, complexity and type. This can be practically used to compare, validate and aid in the repetition of historic experiments. Furthermore, data can be verified via external repositories/sources which will ultimately enhance the scientific merit of in silico experimentation. Our proposed system augments existing applications and therefore does not require users to modify their current experimentation platform. A test case for a pharmacological study is presented to illustrate the proposed system's versatility for reporting and auditing of experiments and their results.

A system for managing data provenance in in silico experiments

Computationally, steady seepage in arbitrary shaped aquifers reduces to a Laplacian free boundary problem. Analytic series solutions can be obtained by iteratively improving an initial estimate. Although the free water table is slowly varying in shape, accurate solutions can be extremely difficult to obtain for the long aspect ratios encountered in typical problems. In previous research, the Neumann condition along the free boundary was used as a cost function. In this paper, we present an update method that uses the Dirichlet condition as the cost function. We find that this approach is significantly more efficient and stable than the previous approach. This enables the determination of very accurate solutions for the water table at low computational cost.

/pdf/a-potential-update-method-for-series-methods-in-steady-e2m06eb77f.pdf

A potential update method for series methods in steady seepage

The title paraphrases a comment made during talks with local mathematics teachers in Townsville. The challenge was laid down. Where are these formulae used? Why do we think they are important? This paper covers some of the answers. In particular, these formulae were used (almost unnoticed) in a project looking at solving the Helmholtz equation on various regions in two dimensions. Some results of this project are presented.

/pdf/trigonometric-formulae-no-one-uses-them-anymore-41v7psnt4m.pdf

Wayne Read

Papers

Online auction deception using a shill bidding agent

A Software Agent for Collecting Real Auction Data from English Online Auctions

A system for managing data provenance in in silico experiments

A potential update method for series methods in steady seepage

Trigonometric formulae?---No one uses them anymore