Graphics shadowing analysis

Visual image is generated on cathode-ray tube screen to scale and is constructed according to dimensions of specified craft. Once displayed, image may be manipulated by several different means

Becoming a (Virtual) Skateboarder: Communities of Practice and the Design of E-Learning

An analysis of a popular video game is used to illustrate how digital technologies can be used to provide learners with an experience of moving from novice to expert in a distinctive, though virtual, community of practice

Scalable Automated Detection of Spiral Galaxy Arm Segments

Given an approximately centered image of a spiral galaxy, we describe an entirely automated method that finds, centers, and sizes the galaxy and then automatically extracts structural information about the spiral arms. For each arm segment found, we list the pixels in that segment and perform a least-squares fit of a logarithmic spiral arc to the pixels in the segment. The algorithm takes about 1 minute per galaxy, and can easily be scaled using parallelism. We have run it on all ~644,000 Sloan objects classified as "galaxy" and large enough to observe some structure. Our algorithm is stable in the sense that the statistics across a large sample of galaxies vary smoothly based on algorithmic parameters, although results for individual galaxies can sometimes vary in a non-smooth but easily understood manner. We find a very good correlation between our quantitative description of spiral structure and the qualitative description provided by humans via Galaxy Zoo. In addition, we find that pitch angle often varies significantly segment-to-segment in a single spiral galaxy, making it difficult to define "the" pitch angle for a single galaxy. Finally, we point out how complex arm structure (even of long arms) can lead to ambiguity in defining what an "arm" is, leading us to prefer the term "arm segments".Comment: 4 pages (twocolumn),5 figures, 2 tables. Submitted to ApJ. Letter

Consuming animals in print: being a live cow on Victorian cattle ships

In 1890s Britain, cattle ships - vessels used to transport live animals internationally - became a point of public and parliamentary discussion. Cattle shipping was not a new mode of meat supply to Britain, with some European routes well established for centuries; however, in the late nineteenth century, traders based in the United States began running cattle ships across the Atlantic Ocean. I argue that transatlantic cattle ships were a particularly modern site of morality and fertile ground for exploring and extending Victorian Britons’ politics of interspecies relations and care. Looking at two contemporaneous anti-cattle shipping pamphlets, by Samuel Plimsoll (1890) and the Humanitarian League (1894) respectively, this article addresses how the issues of humanitarian character, diet and refrigeration technology relate to images of cows aboard American ships. The fact that several nineteenth-century figures drew comparisons with the transatlantic slave trade in attempts to stop or criticise the movement of live cattle is significant to this study, and helps to inform my discussion of advocacy imagery. By studying the photographs and prints that illustrate both pamphlets, I show that the cows’ likenesses were made through absence, primarily of light and of ink, and ask how this shapes their becoming ‘edible’

Illuminance and luminance distributions of a prototype ambient illumination system for Space Station Freedom

Preliminary results of research conducted in the late 1970's indicate that perceptual qualities of an enclosure can be influenced by the distribution of illumination within the enclosure. Subjective impressions such as spaciousness, perceptual clarity, and relaxation or tenseness, among others, appear to be related to different combinations of surface luminance. A prototype indirect ambient illumination system was developed which will allow crew members to alter surface luminance distributions within an enclosed module, thus modifying perceptual cues to match crew preferences. A traditional lensed direct lighting system was compared to the prototype utilizing the full-scale mockup of Space Station Freedom developed by Marshall Space Flight Center. The direct lensed system was installed in the habitation module with the indirect prototype deployed in the U.S. laboratory module. Analysis centered on the illuminance and luminance distributions resultant from these systems and the implications of various luminaire spacing options. All test configurations were evaluated for compliance with NASA Standard 3000, Man-System Integration Standards