Distance, Proximity and Hannah Höch's radical imagination

In her pioneering photomontage Hannah Hoch demonstrates her ambition to transform the viewer's perception through imagination, both hers and theirs. In the process of making photomontage complex relationships between the artist, viewer, and original source material arise in which the displacements involved create distance. Her use of the idea of the cross-section by contrast allows otherwise disparate elements to be brought into close proximity. This paper explores Höch's use of the spatial metaphors of the bridge and the abyss in relation to Salomo Friedländer's concept of Creative Indifference, the Die Brücke group and the influence of Nietzsche's use of the bridge metaphor and his use of the idea of polarity. What's metaphorical use of the image of the abyss could imply spatial relationships but these begin to breakdown and are replaced instead by irreducible and unbridgeable differences in conceptions of reality that imagination allows to coexist simultaneously

Towards Benchmarking Scene Background Initialization

Given a set of images of a scene taken at different times, the availability of an initial background model that describes the scene without foreground objects is the prerequisite for a wide range of applications, ranging from video surveillance to computational photography. Even though several methods have been proposed for scene background initialization, the lack of a common groundtruthed dataset and of a common set of metrics makes it difficult to compare their performance. To move first steps towards an easy and fair comparison of these methods, we assembled a dataset of sequences frequently adopted for background initialization, selected or created ground truths for quantitative evaluation through a selected suite of metrics, and compared results obtained by some existing methods, making all the material publicly available.Comment: 6 pages, SBI dataset, SBMI2015 Worksho

Structure and optics of the anterior segment of the cetacean eye : a thesis presented in fulfilment of the requirements for the degree of Master of Philosophy at Massey University

The anterior segment of the mammalian eye is concerned with the function and maintenance of its optical components, the most important of these being the maintenance of transparency and stable intraocular pressure. The structures of the eye change throughout life. Continuous growth occurs in the lens, and a number of other changes associated with aging also occur, many of which reduce visual capacity. Many of these manifest in humans because of their long life span but have very little relevance in terms of survival. However, other long lived animals such as some birds, reptiles and whales, could be severely compromised by complete or partial blindness associated with aging. The aims of this study were to evaluate the importance of vision as a sense in whales by observation of the structure and optics of the anterior segment, and compare the findings with other species whose visual functions are well known. Pathological changes were recorded where appropriate. The findings in this thesis are based on a three year survey of eyes from 45 whales in which i) differences between species in the size of the globe, lens, and cornea are described ii) the unique histological structure of the uveal tract is demonstrated and defined iii) evidence of emmetropia in both air and water from NMR images of two eyes is given iv) lens shape and capsular features which indicate that there could be a capacity for accommodation, are described, and v) lens pathology (four cataracts and one case of phacolysis) is described in five animals. The largest whales (baleen and sperm) had the largest eyes, but this was mainly due to the thickness of sclera. Internal dimensions showed little variation with respect to body size, suggesting that there is an upper limit on internal size which is dependant on the focal length of the lens, a structure which enlarges only slightly with age. Corneal and lens sizes were especially large in the baleen whales, and particularly small in the sperm whale. The uveal tract was found to be very vascular when compared to other species, and particularly well innervated with specialised nerve endings which are thought to be unique to cetaceans. Although the findings are not conclusive, evidence from this study suggests that the whales' unique uveal vasculature and aqueous drainage methods may be instrumental in modifying the dioptric strength of the eye. The abundance of specialised pressure-receptors in the ciliary body indirectly supports a proposed mechanism for this, whereby the engorged ciliary body raises intraocular pressure causing increased corneal curvature, and releases tension on the zonule to allow 'rounding up' of the lens. Optically, the study showed that eyes from two long-finned pilot whales were emmetropic by virtue of a cornea with only a very small amount of optical power in both air and water, and a very powerful lens (about 72D in water). Emmetropia was thus not affected unduly by transition from air to water as it is in most mammals, where the cornea is optically very significant in air but neutral in water. Lenses in both animals showed an unusual 'bump' on the central posterior : surface, and the increased radius of curvature in this area was responsible for the very high dioptric strength of the lenses. The prevalence of lens pathology, particularly cataracts in young animals, was high. but in all cases the cause was unknown

Mapping and Characterizing Subtidal Oyster Reefs Using Acoustic Techniques, Underwater Videography and Quadrat Counts

Populations of the eastern oyster Crassostrea virginica have been in long-term decline in most areas. A major hindrance to effective oyster management has been lack of a methodology for accurately and economically obtaining data on their distribution and abundance patterns. Here, we describe early results from studies aimed at development of a mapping and monitoring protocol involving acoustic techniques, underwater videography, and destructive sampling (excavated quadrats). Two subtidal reefs in Great Bay, New Hampshire, were mapped with side-scan sonar and with videography by systematically imaging multiple sampling cells in a grid covering the same areas. A single deployment was made in each cell, and a 5-10-s recording was made of a 0.25-m2 area; the location of each image was determined using a differential global position system. A still image was produced for each of the cells and all (n = 40 or 44) were combined into a single photomontage overlaid onto a geo-referenced base map for each reef using Arc View geographic information system. Quadrat (0.25 m2 ) samples were excavated from 9 or 10 of the imaged areas on each reef, and all live oysters were counted and measured. Intercomparisons of the acoustic, video, and quadrat data suggest: (1) acoustic techniques and systematic videography can readily delimit the boundaries of oyster reefs; (2) systematic videography can yield quantitative data on shell densities and information on reef structure; and (3) some combination of acoustics, systematic videography, and destructive sampling can provide spatially detailed information on oyster reef characteristics

Sedimentology and kinematics of a large, retrogressive growth-fault system in Upper Carboniferous deltaic sediments, western Ireland

Growth faulting is a common feature of many deltaic environments and is vital in determining local sediment dispersal and accumulation, and hence in controlling the resultant sedimentary facies distribution and architecture. Growth faults occur on a range of scales, from a few centimetres to hundreds of metres, with the largest growth faults frequently being under-represented in outcrops that are often smaller than the scale of feature under investigation. This paper presents data from the exceptionally large outcrops of the Cliffs of Moher, western Ireland, where a growth-fault complex affects strata up to 60 m in thickness and extends laterally for 3 km. Study of this Namurian (Upper Carboniferous) growth-fault system enables the relationship between growth faulting and sedimentation to be detailed and permits reconstruction of the kinematic history of faulting. Growth faulting was initiated with the onset of sandstone deposition on a succession of silty mudstones that overlie a thin, marine shale. The decollement horizon developed at the top of the marine shale contact for the first nine faults, by which time aggradation in the hangingwall exceeded 60 m in thickness. After this time, failure planes developed at higher stratigraphic levels and were associated with smaller scale faults. The fault complex shows a dominantly landward retrogressive movement, in which only one fault was largely active at any one time. There is no evidence of compressional features at the base of the growth faults, thus suggesting open-ended slides, and the faults display both disintegrative and non-disintegrative structure. Thin-bedded, distal mouth bar facies dominate the hangingwall stratigraphy and, in the final stages of growth-fault movement, erosion of the crests of rollover structures resulted in the highest strata being restricted to the proximity of the fault. These upper erosion surfaces on the fault scarp developed erosive chutes that were cut parallel to flow and are downlapped by the distal hangingwall strata of younger growth faults

Microstructural Characterization of Graphite Spheroids in Ductile Iron

The present work brings new insights by transmission electron microscopy allowing disregarding or supporting some of the models proposed for spheroidal growth of graphite in cast irons. Nodules consist of sectors made of graphite plates elongated along a hai direction and stack on each other with their c axis aligned with the radial direction. These plates are the elementary units for spheroidal growth and a calculation supports the idea that new units continuously nucleate at the ledge between sectors

Valuing congestion costs in the British Museum

Museums are potentially congestible resources because the exhibits they contain are, in any relevant sense of the word, irreproducible. Insofar as visitor congestion diminishes the value of individuals’ visits it constitutes an additional reason for charging for admission to museums, albeit one not previously considered. A policy of free access to a museum containing unique treasures may dissipate the economic benefits of the museum. Within the context of an empirical study undertaken for the British Museum using stated preference techniques it is shown that the congestion cost posed by the marginal visitor is quite high. Notwithstanding the argument that visits to the museum may possess external benefits, this points to the desirability of instigating charges for admission. Furthermore, it is shown that the marginal congestion cost decreases at least over a range as visitor numbers increase. In other words beyond certain levels introducing more visitors does not worsen congestion. This suggests that, contrary to what is often assumed, charging more during periods of high demand may be undesirable. Insofar as congestion is a widespread phenomenon in important museums, galleries and sites of historical heritage the issues raised in this paper as well as the methodology devised to determine congestion costs could have widespread application

Elephant and River Street

Photomontage