Journals at Carleton University
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Do Police Stations Really Deter Crime?
No full textMany believe that the presence of a police station deters crime in the surrounding area. The source article tested this deterrence hypothesis and determined that when police stations were closed in a large metropolitan area, crime did not increase in the surrounding area (and numerous types of crime decreased).
Some of these crime decreases may be a result of decreased crime reporting by the public when local police stations close, due to increased inconvenience, which suggests an easy to access online platform may assist in crime reporting if local police stations do close.
This study suggests that a focus on other, more proven crime deterrence methods (e.g., hotspot policing) is more likely to reduce crime compared to a reliance on the simple presence of police stations in the area
Building Transparency Through a Canadian Police Use-of-Force Database
No full textNo police-sponsored or government-sponsored national use-of-force database currently exists in Canada.
Creating a national use-of-force database would help to increase police transparency, improve public perceptions of police legitimacy by showing that force is used rarely and is generally justified when it is used, enhance our understanding of use-of-force dynamics, lead to potential mitigation strategies to reduce use-of-force incidents, and address public misconceptions aboutpolice use-of-force.
Establishing a national use-of-force database will also likely come with challenges associated with inconsistent reporting, resistance from the police community, establishment of standardized inclusion criteria, missing data due to privacy issues (e.g., health data), and database ownership concerns
Women in State Law Enforcement: A 20-Year Review (2000-2020)
No full textData from six Law Enforcement Management and Administrative Statistics (LEMAS) surveys between 2000 and 2020 were analyzed to examine gender diversity across the 49 primary state law enforcement agencies in the United States.
Representation varied broadly across the states; however, the overall percentage of women in state law enforcement increased slightly over the past two decades.
State law enforcement agencies looking to increase women’s representation must be continuously creative with recruitment efforts and consider utilizing technical assistance such as the 30x30 Initiative to facilitate change
Officer Sex, Grip Strength, and Marksmanship Performance
No full textGrip strength significantly impacts a police officer\u27s ability to pass a pistol qualification.
On average, Canadian female officers in the current study exhibited lower grip strength and pistol qualification scores than male officers.
Results from the study suggest that officer sex may be indirectly related to pistol qualification scores through its relationship with grip strength.
Police services may want to consider introducing more grip strength training or adopting pistols that have lighter trigger pull weights
Geometric hitting set for line-constrained disks and related problems
No full textGiven a set of weighted points and a set of disks in the plane, the hitting set problem is to compute a subset of points of such that each disk contains at least one point of and the total weight of all points of is minimized. The problem is known to be NP-hard. In this paper, we consider a line-constrained version of the problem in which all disks are centered on a line . We present an time algorithm for the problem, where is the number of pairs of disks that intersect. For the unit-disk case where all disks have the same radius, the running time can be reduced to . In addition, we solve the problem in time in the and metrics, in which a disk is a square and a diamond (assuming that is horizontal), respectively. Our techniques can also be used to solve other geometric hitting set problems. For example, given in the plane a set of weighted points and a set of half-planes, we solve in time the problem of finding a minimum weight hitting set of for . This improves the previous best algorithm of time by nearly a quadratic factor
Simplification of polyline bundles of graphs and trees
No full textPolyline simplification is a well-studied optimization problem, in which a given polyline shall be replaced by a polyline with fewer vertices which still represents the shape of the original polyline faithfully. In this paper, we propose and study a generalization of the polyline simplification problem. Instead of a single polyline, we are given a set of polylines possibly sharing some line segments and vertices. We call such a set a polyline bundle. The task is to simplify each polyline of a given polyline bundle by keeping a subset of its vertices such that (i) the Hausdorff or Fréchet distance between and its simplified counterpart does not exceed a given distance threshold , (ii) a shared vertex is either kept or discarded in all polylines of the polyline bundle (we refer to this requirement as consistency) and (iii) the number of kept vertices in the polyline bundle is minimized. To justify this definition, we argue that consistency is crucial to get meaningful and aesthetically pleasing outputs.
Regarding the computational complexity of polyline bundle simplification, we prove that this problem is NP-hard to approximate within a factor of for any \varepsilon > 0, where is the number of vertices in the polyline bundle. This inapproximability even applies to planar inputs and also to instances with only polylines. However, we identify the sensitivity of the solution to the choice of the distance threshold as a reason for this strong inapproximability. In particular, we prove that if we employ the Fréchet distance and allow to be exceeded by a factor of in the solution, then we can find a simplified polyline bundle with no more than vertices in polytime, providing us with an efficient bi-criteria approximation. In addition, we show that the polyline simplification problem is solvable in polytime in case the polylines form a rooted tree. We further present a greedy heuristic that decomposes general bundles into tree bundles, which then can be simplified individually and optimally. In our experimental study, we compare the performance of the bi-criteria approximation algorithm and the tree bundle decomposition algorithm on public transit networks and movement trajectories. We show that in case the polylines form grid-like structures, the bi-criteria approximation algorithm outputs smaller simplifications, but the tree bundle decomposition algorithm scales better and produces superior results on polyline bundles derived from paths in embedded road networks
Density approximation for moving groups
No full textSets of moving entities can form groups which travel together for significant amounts of time. Tracking such groups is an important analysis task in a variety of areas, such as wildlife ecology, urban transport, or sports analysis. Correspondingly, recent years have seen a multitude of algorithms to identify and track meaningful groups in sets of moving entities. However, not only the mere existence of one or more groups is an important fact to discover; in many application areas the actual shape of the group carries meaning as well. In this paper we initiate the algorithmic study of the shape of a moving group. We use kernel density estimation to model the density within a group and show how to efficiently maintain an approximation of this density description over time. Furthermore, we track persistent maxima which give a meaningful first idea of the time-varying shape of the group. By combining several approximation techniques, we obtain a kinetic data structure that can approximately track persistent maxima efficiently
Flips in colorful triangulations
No full textThe associahedron is the graph that has as nodes all triangulations of a convex -gon, and an edge between any two triangulations that differ in a flip operation. A flip removes an edge shared by two triangles and replaces it by the other diagonal of the resulting 4-gon. In this paper, we consider a large collection of induced subgraphs of obtained by Ramsey-type colorability properties. Specifically, coloring the points of the -gon red and blue alternatingly, we consider only colorful triangulations, namely triangulations in which every triangle has points in both colors, i.e., monochromatic triangles are forbidden. The resulting induced subgraph of on colorful triangulations is denoted by . We prove that has a Hamilton cycle for all , resolving a problem raised by Sagan, i.e., all colorful triangulations on points can be listed so that any two cyclically consecutive triangulations differ in a flip. In fact, we prove that for an arbitrary fixed coloring pattern of the points with at least 10 changes of color, the resulting subgraph of on colorful triangulations (for that coloring pattern) admits a Hamilton cycle. We also provide an efficient algorithm for computing a Hamilton path in that runs in time on average per generated node. This algorithm is based on a new and algorithmic construction of a tree rotation Gray code for listing all -vertex -ary trees that runs in time on average per generated tree
“A Beast I Am, lest a Beast I Become” – Tabletop Role-Playing Games Vampires and the Questioning of Power
No full textBram Stoker\u27s late-Victorian gothic take on the figure of the vampire revealed its many ambiguous facets and opened up new avenues for future exploration. His Dracula is first and foremost a menacing figure from the margins of the West, invading the heart of the British Empire (leading to Nosferatu, Murnau, 1922). At the same time, he is a defender of Christianity, who became monstrous by confronting the foreign enemy (particularly visible in Dracula Untold, Shore, 2014). He is a nocturnal predator seducing women (Blood of Dracula, Strock, 1957), but also an agent supporting female emancipation oppressed by patriarchal and religious yoke (Coppola\u27s romantic vision in 1992). This interpretative variety is reflected in the adaptation of the vampire figure in the medium of tabletop role-playing games. From Dungeons & Dragons (Gygax and Arneson, 1974) to Vampire: The Masquerade (Rein-Hagen, 1991), via Chill (Sanchez et al., 1984), the vampire has in turn taken on the traits of the nemesis to be slain, the power fantasy, rebellion against the established order and lyrical, tragic romanticism. This article offers to examine the evolution of the vampire figure in tabletop role-playing between 1974 and 2020. Such a period obviously doesn\u27t allow us to claim exhaustivity, but by examining a few cases that have marked the history of the medium, we can account for the relationship between this figure and the development of role-playing\u27s means of expression, on the one hand, and cultural and social transformations, on the other. From adversary to protagonist, from bloodthirsty monster to sensitive being, the vampire has contributed to expanding the medium\u27s expressive possibilities. As Buffy proclaimed (season 7, episode 1), "It\u27s about power", and the vampire invites us to rethink its use and distribution
Viral Horror: Host and the Fear of Infection During the COVID-19 Pandemic
No full textThe COVID-19 global pandemic foregrounded anxieties about bodies, particularly the infection, suffering, and death of the body. As a body genre, horror is especially adept at addressing these anxieties by affecting the spectator’s body through the exhibition and torture of the body on screen (Clover 189). This article examines references to the COVID-19 pandemic in Rob Savage’s Host (2020), which analogizes pandemic anxieties about infection to a paranormal haunting of a séance held over Zoom. Associations between the demon as both a computer virus and a stand-in for the COVID-19 virus not only trouble the “safe” methods of online communication that became quotidian during lockdown periods, but also replicate images of infected and dead bodies that pervaded digital channels throughout the pandemic. For the viewer, the film’s horror stems from the overlap between fiction and reality, as well as reliving the powerlessness that characterized digital witnessing while being in lockdown. Overall, the film advocates for quarantine protocols, using the young friend group as a cautionary tale to suggest that in spite of the inadequacies and terrors that arise from life during lockdown, it is best to stay at home