University of Victoria

About: University of Victoria is a education organization based out in Victoria, British Columbia, Canada. It is known for research contribution in the topics: Population & Galaxy. The organization has 14994 authors who have published 41051 publications receiving 1447972 citations. The organization is also known as: Victoria College.

Towards a theory of domination in graphs

Abstract: This paper presents a quick review of results and applications concerning dominating sets in graphs. The domatic number of a graph is defined and studied. It is seen that the theory of domination resembles the well known theory of colorings of graphs.

An approach to detecting duplicate bug reports using natural language and execution information

Abstract: An open source project typically maintains an open bug repository so that bug reports from all over the world can be gathered. When a new bug report is submitted to the repository, a person, called a triager, examines whether it is a duplicate of an existing bug report. If it is, the triager marks it as duplicate and the bug report is removed from consideration for further work. In the literature, there are approaches exploiting only natural language information to detect duplicate bug reports. In this paper we present a new approach that further involves execution information. In our approach, when a new bug report arrives, its natural language information and execution information are compared with those of the existing bug reports. Then, a small number of existing bug reports are suggested to the triager as the most similar bug reports to the new bug report. Finally, the triager examines the suggested bug reports to determine whether the new bug report duplicates an existing bug report. We calibrated our approach on a subset of the Eclipse bug repository and evaluated our approach on a subset of the Firefox bug repository. The experimental results show that our approach can detect 67%-93% of duplicate bug reports in the Firefox bug repository, compared to 43%-72% using natural language information alone.

Evolution of the scale factor with a variable cosmological term

Abstract: The evolution of the scale factor $a(t)$ in Friedmann models (those with zero pressure and a constant cosmological term $\ensuremath{\Lambda})$ is well understood, and elegantly summarized in the review of Felten and Isaacman [Rev. Mod. Phys. 58, 689 (1986)]. Developments in particle physics and inflationary theory, however, increasingly indicate that $\ensuremath{\Lambda}$ ought to be treated as a dynamical quantity. We reexamine the evolution of the scale factor with a variable $\ensuremath{\Lambda}$ term, and also generalize the treatment to include nonzero pressure. New solutions are obtained and evaluated using a variety of observational criteria. Existing arguments for the inevitability of a big bang (i.e., an initial state with $a=0)$ are substantially weakened, and can be evaded in some cases with ${\ensuremath{\Lambda}}_{0}$ (the present value of $\ensuremath{\Lambda})$ well below current experimental limits.