Disk arrays were proposed in the 1980s as a way to use parallelism between multiple disks to improve aggregate I/O performance. Today they appear in the product lines of most major computer manufacturers. This paper gives a comprehensive overview of disk arrays and provides a framework in which to organize current and future work. The paper first introduces disk technology and reviews the driving forces that have popularized disk arrays: performance and reliability. It then discusses the two architectural techniques used in disk arrays: striping across multiple disks to improve performance and redundancy to improve reliability. Next, the paper describes seven disk array architectures, called RAID (Redundant Arrays of Inexpensive Disks) levels 0-6 and compares their performance, cost, and reliability. It goes on to discuss advanced research and implementation topics such as refining the basic RAID levels to improve performance and designing algorithms to maintain data consistency. Last, the paper describes six disk array prototypes or products and discusses future opportunities for research. The paper includes an annotated bibliography of disk array-related literature.

The spectre of climate change that is unfolding now is undeniably a cumulative impact of anthropogenic interference in the climate system over the last two centuries. The science is clear and the policy community is being increasingly convinced and galvanised into action to address this emergent challenge in light of the associated economic and human dimensions. The impacts of climate change ranging from sea level rise, melting ice caps and glaciers, severe weather events, drought, flooding, warming, subtle changes in ecosystems – will impinge on every aspect of society and economic life. The costs of inaction will more than outweigh the costs of action. There is only a narrow window of opportunity to redress the situation. The Intergovernmental Panel on Climate Change (IPCC) in its Fourth Assessment Report has

In this paper the role of family structure in mitigating income volati-lity in the absence of income insurance in low-income agricultural environments is discussed. Hypotheses concerning the relationship between the membership, size and composition of households and insurance-based income transfers

, the differences among metabolite target analysis, metabolite profiling, and metabolic fingerprinting are clarified, and terms are defined. Current approaches are examined, and potential applications are summarized with a special emphasis on data mining and mathematical modelling of metabolism.

Copyright Statement Attention is drawn to the fact that the copyright of this thesis rests with the author, and that no quotation from the thesis and no information derived from it may be published without the prior written consent of the author. Signed: Date:

This reprinting is corrected to software version 2.10

of the terrestrial biosphere carbon and kinetic energy exchanges at the soil surface and plants, as well as the dynamic soil-plant nitrogen cycles. In this study, improvements made in parameterization of different plant functional types (PFTs) were evaluated, and then, model was used to assess the effects

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and transfer of hydrocarbons on different

Soil is a complex and dynamic biological system, and still in 2003 it is difficult to determine the composition of microbial communities in soil. We are also limited in the determination of microbially mediated reactions because present assays for determining the overall rate of entire metabolic