n the current debates around evaluation, quasi-experimental methods are considered by some to be the best way to know what works. They view narrative-based evaluation with some disdain. Stories are, they say, only perceptions. They can’t give you the ‘hard facts and figures’ that are needed to know what works and what to do next. And a handful of stories, no matter how in-depth, cannot lead to ...

Software measurement has the potential to play an important role in risk management during product development. Metrics incorporated into predictive models can give advanced warning of potential risks. However, the common approach of using simple regression models, notably to predict software defects, can lead to inappropriate risk management decisions. These naïve models should be replaced wit...

What are the limits of physics’ explanatory power? Can physics explain everything? In this paper I discuss a somewhat broader question: can physics explain existence itself? I argue that genuinely ultimate explanations—those that really explain everything—involve the most basic and most general elements of logic. Such explanations cannot be done within physics unless physics undergoes a methodo...

In this work the authors develop a mathematical model for the dynamics of a major helminth parasite of man, schistosomiasis. The model is a system of coupled non-linear equations. Numerical experimentations with the model reveal the remarkable stability of the dynamics of schistosomiasis. The steady state is invariably reached within 10-15 years of the start of the infection. A numerical soluti...

People travel all the time, whether it be commuting, weekend bike trips or transportation of goods. We often require our smartphones or computers to find the quickest route for us to get somewhere. But what if we are not interested merely in the shortest or the fastest option and, instead, desire to choose from several alternatives that meet our expectations in a whole range of criteria? We kno...

Maximize ZD = b T y s.t. (D) A y + s = c, s ≥ 0n. where we have here chosen to add slack variables s ≥ 0n. The simplex method, as presented previously, works by starting with an initial basic feasible solution to (P) (which can be found via a phase 1 problem). However, what if a dual feasible basis is immediately available, whereas a basic feasible solution to (P) is harder to obtain? Can this ...

OF THE DISSERTATION CUBEGRADES – GENERALIZATION OF ASSOCIATION RULES TO MINE LARGE DATASETS by AMIN ARSHAD ABDULGHANI Dissertation Director: Tomasz Imielinski Cubegrades are generalization of association rules which represent how a set of measures (aggregates) is affected by modifying a cube through specialization (rolldown), generalization (rollup) and mutation (which is a change in one of the...

Several interactive methods exist to identify nondominated solutions in a Multiple Objective Mixed Integer Linear Program. But what if the Decision Maker is also interested in sorting those solutions (assigning them to pre-established ordinal categories)? We propose an interactive ‘‘branch-and-bound like’’ technique to progressively build the nondominated set, combined with ELECTRE TRI method (...