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.

A Continuous Double Auction (CDA) is a powerful auction mechanism used in online share trading. A CDA has many
buyers and sellers continually exchanging items. Implementing an online CDA in software is more complicated than a regular online auction (such as eBay). This paper describes our experiences with implementing an online CDA. We present the model as an abstraction of the online share trading process, and discuss implementation specific details. We describe the major software components, address web site navigation and object-oriented software design. An online CDA database schema is presented along with a discussion regarding timing issues. We show how bids are cleared and contrast differing matching strategies. We also investigate CDA software bidding agents, present an agent application programming interface, and a description of different bidding agent strategies. Online CDA privacy and security considerations are also discussed. The auction model is simple/concise, and presented as a general guide on how to basically implement an online CDA system.

A software architecture for continuous double auctions

Since its development in 1925, Terzaghi’s expression for the average degree of consolidation has been extensively used in teaching, research and consulting to determine the consolidation settlement that has taken place at a specific time in a geotechnical problem. Recent research by the authors has revealed that the term degree of consolidation is not very meaningful when the initial pore pressure distribution is highly skewed. In view of these findings, a review of all aspects of Terzaghi’s consolidation theory is required, particularly when considering asymmetric initial pore pressure distributions. An exact method for estimating the consolidation settlement of a clay stratum using the mass flux per unit area out of the drainage boundaries is proposed. Graphical representations of both exact and traditional methods reveal identical average degree of consolidation curves. In light of this, Terzaghi’s expression for the average degree of consolidation was re-examined. Upon application of the original governing one-dimensional consolidation equation, it was found that the traditional and exact methods for calculating the average degree of consolidation are identical. Thus, the widespread proclivity for geotechnical engineers to use Terzaghi’s average degree of consolidation equation to estimate the consolidation settlement of a clay stratum has been validated.

A Critical Reappraisal of the Average Degree of Consolidation

Wireless sensor networks (WSNs) employ middleware solutions to coordinate their sensors and provide web services for managing data. Adding/configuring a new or existing sensor requires modification to the middleware and web service. To integrate hundreds of sensors with different capabilities, a system needs to support all the encodings, models and services for registering, tasking and querying sensors. We present an intelligent agent, which provides automatic semantic-based registration/configuration in a large-scale sensor observation system. The agent can react to any changes internally/externally made (i.e., adding a new sensor or sending a task request to sensors/support systems). The agent makes a 'smart' decision on which system function to use by integrating a semantic representation of sensor network data including middleware and web service specifications and applying logical rules to the knowledge-base. The agent's operation is demonstrated using two real-world systems represented in RDF using a domain ontology that extends the W3C SSN-XG ontology.

An intelligent agent system for managing heterogeneous sensors in dispersed and disparate wireless sensor network

Most models of seepage in homogeneous aquifers assume a two dimensional flow regime. We present a series method that can be used to provide three dimensional solutions for saturated seepage problems in real time. The aquifer lies on a horizontal aquiclude and can have arbitrary soil surface geometry. We show that exponential convergence can be achieved for the correct choice of soil surface representation. The series solutions obtained are used to generate velocity profiles and streamline solutions, once again in real time. These solutions demonstrate the significant differences between two and three dimensional models of seepage.

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Series solutions for seepage in three dimensional aquifers

Online auctions are inherently insecure and there exist many opportunities for participants to cheat. Cryptographic protocols can be applied to help alleviate some of these problems. However, different auction types have differing security requirements. This makes it difficult to construct schemes to prevent all possible forms of dubious behaviour. This paper presents a survey of cryptographic schemes that have been proposed for conducting private and secure auctions. The major auction types are investigated and their privacy and security requirements contrasted. We provide a uniform analysis of each auction scheme's functional components and analyse the efficiency of the security mechanisms. The paper's motivation is to give an all-encompassing overview of auction privacy and security, which has not been documented elsewhere. This paper supports supplementary research by the author into online auction fraud and security issues. We show that most schemes are currently not practical and there are conflicting perspectives regarding security requirements. Avenues for future research are proposed with regard to the present lacking state of commercial online auction security.

Wayne Read

Papers

A software architecture for continuous double auctions

A Critical Reappraisal of the Average Degree of Consolidation

An intelligent agent system for managing heterogeneous sensors in dispersed and disparate wireless sensor network

Series solutions for seepage in three dimensional aquifers

Cryptographic online auction schemes