This book is based on the author's PhD thesis which was selected as the winning thesis of the 1993 ACM Doctoral Dissertation Competition. The author improved the presentation and included the progress achieved since the thesis was approved by the University of California at Berkeley.
This work is a fascinating piece of theoretical computer science research building on deep results from different areas. It provides new theoretical insights and advances applicable techniques in such different areas as computational complexity, efficient (randomized) checking of proofs, programs and polynomials, approximation algorithms, NP-complete optimization, and error-detection and error-correction algorithms in coding theory.

Soil erosion has been recognized as a global threat against the sustainability of natural ecosystem. Erosion Modelling Under Different Land Use Management Practices is the research work carried out at the University of Western Sydney (UWS), to assist in combating against this threat. This research work is devoted in addressing the soil erosion issues associated with urban construction activities. The Revised Universal Soil Loss Equation (RUSLE) was employed in this research work and the parameters associated with the model were calibrated. This model was chosen for calibration, as it has been proven as an easy to use tool yet providing reasonable result. Validation of the model was also carried out with an independent data set. Large-scale rainfall simulators developed at UWS were used for rainfall simulation at two sites with diverse soil types: dispersive clayey soil at Penrith and highly permeable sandy soil at Somersby, both in New South Wales (NSW). 30 mins duration rainfall intensities with Average Recurrence Intervals (ARIs) ranging from one year to 10 year were applied to generate artificial rainfall.

Many fundamental combinatorial problems, arising in such diverse fields as artificial intelligence, logic, graph theory, and linear algebra, can be formulated as Boolean constraint satisfaction problems (CSP). This book is devoted to the study of the complexity of such problems. The authors' goal is to develop a framework for classifying the complexity of Boolean CSP in a uniform way. In doing so, they bring out common themes underlying many concepts and results in both algorithms and complexity theory. The results and techniques presented here show that Boolean CSP provide an excellent framework for discovering and formally validating "global" inferences about the nature of computation.

This book presents a novel and compact form of a compendium that classifies an infinite number of problems by using a rule-based approach. This enables practitioners to determine whether or not a given problem is known to be computationally intractable. It also provides a complete classification of all problems that arise in restricted versions of central complexity classes such as NP, NPO, NC, PSPACE, and #P.