Web services based state of the environment reporting

The Environmental Sciences Division within Queensland Environmental Protection Agency works to monitor, assess and model the condition of the environment. The Division has as a legislative responsibility to produce a whole-of-government report every four years dealing environmental conditions and trends in a ”State of the Environment report” (SoE)[1][2][3]. State of Environment Web Service Reporting System is a supplementary web service based SoE reporting tool, which aims to deliver accurate, timely and accessible information on the condition of the environment through web services via Internet [4][5]. This prototype provides a scientific assessment of environmental conditions for a set of environmental indicators. It contains text descriptions and tables, charts and maps with spatiotemporal dimensions to show the impact of certain environmental indicators on our environment. This prototype is a template based indicator system, to which the administrator may add new sql queries for new indicator services without changing the architecture and codes of this template. The benefits are brought through a service-oriented architecture which provides an online query service with seamless integration. In addition, since it uses web service architecture, each individual component within the application can be implemented by using different programming languages and in different operating systems. Although the services showed in this demo are built upon two datasets of regional ecosystem and protection area of Queensland, it will be possible to report on the condition of water, air, land, coastal zones, energy resources, biodiversity, human settlements and natural culture heritage on the fly as well. Figure 1 shows the architecture of the prototype. In the next section, I will discuss the research tasks in the prototype.

Increased availability and scalability for clustered services via the wait time calculation, trust based filtering and redirection of TCP connection requests

The paper describes two new transport layer (TCP) options and an expanded transport layer queuing strategy that facilitate three functions that are fundamental to the dispatching-based clustered service. A transport layer option has been developed to facilitate. the use of client wait time data within the service request processing of the cluster. A second transport layer option has been developed to facilitate the redirection of service requests by the cluster dispatcher to the cluster processing member. An expanded transport layer service request queuing strategy facilitates the trust based filtering of incoming service requests so that a graceful degradation of service delivery may be achieved during periods of overload - most dramatically evidenced by distributed denial of service attacks against the clustered service. We describe how these new options and queues have been implemented and successfully tested within the transport layer of the Linux kernel.

Investigations into an optimal transmission scheme for a MIMO system operating in a ricain fading environment

This paper describes investigations into an optimal transmission scheme for a multiple input multiple output (MIMO) system operating in a Rician fading environment. The considerations are reduced to determining a covariance matrix of transmitted signals which maximizes the MIMO capacity under the condition that the receiver has perfect knowledge of the channel while the transmitter has the information about selected statistical quantities which are measured at the receiver. An optimal covariance matrix, which requires information of the Rice factor and the signal to noise ratio, is determined. The transmission scheme relying on the choice of the proposed covariance matrix outperforms the other transmission schemes which were reported earlier in the literature. The proposed scheme realizes an upper bound limit for the MIMO capacity under arbitrary Rician fading conditions. ©2005 IEEE