Exotic fish and decreasing habitats vis-à-vis conservation of freshwater fish biodiversity of Bangladesh

Multiple stressors including biological invasion have long been recognised in conservation of freshwater fish biodiversity. Works in this line have, however, been still scanty in Asia and South America – the continents known for rich biodiversity. In this study, the first of its type in Bangladesh, impacts of exotic fish and declining habitats on native fishes have been investigated. Regression and correlation analyses of 16 years production data of ponds, practically the only habitat where exotic fish are cultured commonly with indigenous ones, reveals that a maximum of 25% of the abundance decrease of native fish could be due to the effects of five commonly cultured exotic fish. Rest of the decline might largely be due to shrinkage, degradation, and destruction of habitats. Inland habitats other than ponds shrink, commonly, by about 80 % during the dry season, and most rivers are heavily polluted except for the brief mid rainy season. Decline in native fish populations may result in reduced genetic diversity. Another potential danger is the probable genetic introgression from the less fit hatchery-originated fish with the wild ones. The study concludes that the native freshwater fishes are endangered by declining habitats, exotic fishes, genetic consequences of hatchery supplementatio

Soft Computing Approaches to DPLL SAT Solver Optimization

Digital electronic systems are now so large and complex that ensuring their correct functionality has become the most time-consuming part of their design. Formal verification allows the exhaustive, automatic testing of functional properties of such systems without requiring the designer to create individual test cases manually, which is time-consuming as well as prone to errors and oversights. The properties are first transformed into instances of the Boolean satifiability problem (SAT), which are then solved with SAT solvers. The most efficient SAT solvers for industrial SAT problems are based on enhanced versions of the DPLL algorithm which employs a number of heuristics to guide the search for a solution. Solving times are highly dependent on the choice of the solver's heuristic parameters, and adjusting the heuristics optimally is a complex task in itself. This work presents and tests a new, fully automatic optimization procedure for a SAT solver's heuristic parameters that is based on using local search algorithms which attempt to find optimal parameters for training sets of SAT problems; a result configuration is synthesized from the gathered data. For the optimization two subtypes of Evolutionary Algorithms (local search algorithms that mimic Darwinian evolution), Genetic Algorithms and Evolution Strategies, were tested. The target of optimization was the well known open-source SAT solver MiniSAT. It could be shown that the parameter configurations generated by the automatic procedure are competitive with the default parameters set by human experts

1 SAT

Abstract. The Boolean satisfiability problem (SAT) can be solved efficiently with variants of the DPLL algorithm. For industrial SAT problems, DPLL with conflict analysis dependent dynamic decision heuristics has proved to be particularly efficient, e.g. in Chaff. In this work, algorithms that initialize the variable activity values in the solver MiniSAT v1.14 by analyzing the CNF are evolved using genetic programming (GP), with the goal to reduce the total number of conflicts of the search and the solving time. The effect of using initial activities other than zero is examined by initializing with random numbers. The possibility of countering the detrimental effects of reordering the CNF with improved initialization is investigated. The best result found (with validation testing on further problems) was used in the solver Actin, which was submitted to SAT-Race 2006. The SAT problem is the question if there exists an assignment to the variables of a Boolean function f so that f evaluates to true (f is satisfiable), or if n

Computerization of banking operation in Bangladesh

This paper is about the computerization of the banking operation of two of the largest banks in Bangladesh. The discussion deals with the issues faced in rolling out Core Banking System (CBS) in Sonali Bank and Rupali Bank. The system we studied focuses on centralizing computing operations by consolidating IT infrastructure; this system is meant to replace the existing distributed computing components. In this paper, we will highlight both the technical and human issues we have faced. The paper highlights the context of the work, the scale of the problem, issues and challenges faced during the roll-out. The intricacies of implementing a large-scale system such as CBS are educational, but nevertheless daunting. The findings of the paper articulated that obstacles could be overcome through human ingenuity and discipline. The paper stresses that structural approach of software development is necessary for long-term success of a project and properly trained software professionals is integral to the development of a complex software project

Estimating prevalence and determinants of chronic kidney disease among type 2 diabetes behind the different health insurance coverage: Findings from the rural northeastern region of Thailand

Dataset for the article "Estimating prevalence and determinants of chronic kidney disease among type 2 diabetes behind the different health insurance coverage: Findings from the rural northeastern region of Thailand