Laws for rewriting queries containing division operators

Relational division, also known as small divide, is a derived operator of the relational algebra that realizes a many-to-one set containment test, where a set is represented as a group of tuples: Small divide discovers which sets in a dividend relation contain all elements of the set stored in a divisor relation. The great divide operator extends small divide by realizing many-to-many set containment tests. It is also similar to the set containment join operator for schemas that are not in first normal form. Neither small nor great divide has been implemented in commercial relational database systems although the operators solve important problems and many efficient algorithms for them exist. We present algebraic laws that allow rewriting expressions containing small or great divide, illustrate their importance for query optimization, and discuss the use of great divide for frequent itemset discovery, an important data mining primitive. A recent theoretic result shows that small divide must be implemented by special purpose algorithms and not be simulated by pure relational algebra expressions to achieve efficiency. Consequently, an efficient implementation requires that the optimizer treats small divide as a first-class operator and possesses powerful algebraic laws for query rewriting

Improved Methods for Network Screening and Countermeasure Selection for Highway Improvements

Network screening and countermeasure selection are two crucial steps in the highway improvement process. In network screening, potential improvement locations are ranked and prioritized based on a specific method with a set of criteria. The most common practice by transportation agencies has been to use a simple scoring method, which, in general, weighs and scores each criterion and then ranks the locations based on their relative overall scoring. The method does not deal well with criteria that are qualitative in nature, nor does it account for the impacts of correlation among the criteria. The introduction of Analytic Hierarchy Process (AHP) provides agencies with a method to include both quantitative and qualitative criteria. However, it does not address the issue on correlation. This dissertation explores the use of both Analytic Network Process (ANP) and Fuzzy Analytic Network Process (FANP) for their potential capabilities to address both issues. Using urban four-lane divided highways in Florida for bicycle safety improvements, both ANP and FANP were shown to provide more reasonable rankings than AHP, with FANP providing the best results among the methods. After the locations are ranked and prioritized for improvements, the next step is to evaluate the potential countermeasures for improvements at the selected top-ranked locations. In this step, the standard practice has been to use Crash Modification Factors (CMFs) to quantify the potential impacts from implementing specific countermeasures. In this research, CMFs for bicycle crashes on urban facilities in Florida were developed using the Generalized Linear Model approach with a Zero-Inflated Negative Binomial (ZINB) distribution. The CMFs were tested for their spatial and temporal transferability and the results show only limited transferability both spatially and temporally. The CMFs show that, in general, wider lanes, lower speed limits, and presence of vegetation in the median reduce bicycle crashes, while presence of sidewalk and sidewalk barrier increase bicycle crashes. The research further considered bicycle exposure using the bicycle activity data from the Strava smartphone application. It was found that increased bicycle activity reduces bicycle crash probabilities on segments but increases bicycle crash probabilities at signalized intersections. Also, presence of bus stops and use of permissive signal phasing at intersections were found to increase bicycle crash probabilities

The New Unhistoricism in Queer Studies

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155635/1/2013_Traub_New_unhistoricism.pd

Automated Reasoning

This volume, LNAI 13385, constitutes the refereed proceedings of the 11th International Joint Conference on Automated Reasoning, IJCAR 2022, held in Haifa, Israel, in August 2022. The 32 full research papers and 9 short papers presented together with two invited talks were carefully reviewed and selected from 85 submissions. The papers focus on the following topics: Satisfiability, SMT Solving,Arithmetic; Calculi and Orderings; Knowledge Representation and Jutsification; Choices, Invariance, Substitutions and Formalization; Modal Logics; Proofs System and Proofs Search; Evolution, Termination and Decision Prolems. This is an open access book

Masculinities in Peacekeeping: Limits and transformations of UNSCR 1325 in the South African National Defence Force

This report takes a closer look by investigating the ways that UNSCR 1325 has been conceptualized and put into practice in the South African National Defence Force. South Africa is deploying a relatively high proportion of female peacekeepers, but shortcomings of UNSCR 1325, specifically related to gender essentialisms, have affected discourses within the armed forces. While this has led to contradictions and contestations concerning sameness and difference among male and female peacekeepers, the study also reveals a critical engagement with military peacekeeper masculinities, pointing towards a surpassing of the limited premise of UNSCR 1325

Nature’s Optics and Our Understanding of Light

Optical phenomena visible to everyone abundantly illustrate important ideas in science and mathematics. The phenomena considered include rainbows, sparkling reflections on water, green flashes, earthlight on the moon, glories, daylight, crystals, and the squint moon. The concepts include refraction, wave interference, numerical experiments, asymptotics, Regge poles, polarisation singularities, conical intersections, and visual illusions

Evolving Complexity and Similarity in an Artificial Life Framework based on Formal Language Theory

In this thesis, a formal framework where the evolution of biological complexity can be studied in an objective way is defined. That objectivity is due to state complexity for regular languages is used and it is a well-known and rigorous complexity measure. Such a framework is composed of a population of cyclic unary regular languages (individuals) that try to adapt to a given environment (that also consists of cyclic unary regular languages) by means of evolutionary computation