Temporal loudness weights: Primacy effects, loudness dominance and their interaction

Loudness judgments of sounds varying in level across time show a non-uniform temporal weighting, with increased weights assigned to the beginning of the sound (primacy effect). In addition, higher weights are observed for temporal components that are higher in level than the remaining components (loudness dominance). In three experiments, sounds consisting of 100- or 475-ms Gaussian wideband noise segments with random level variations were presented and either none, the first, or a central temporal segment was amplified or attenuated. In Experiment 1, the sounds consisted of four 100-ms segments that were separated by 500-ms gaps. Previous experiments did not show a primacy effect in such a condition. In Experiment 2, four- or ten-100-ms-segment sounds without gaps between the segments were presented to examine the interaction between the primacy effect and level dominance. As expected, for the sounds with segments separated by gaps, no primacy effect was observed, but weights on amplified segments were increased and weights on attenuated segments were decreased. For the sounds with contiguous segments, a primacy effect as well as effects of relative level (similar to those in Experiment 1) were found. For attenuation, the data indicated no substantial interaction between the primacy effect and loudness dominance, whereas for amplification an interaction was present. In Experiment 3, sounds consisting of either four contiguous 100-ms or 475-ms segments, or four 100-ms segments separated by 500-ms gaps were presented. Effects of relative level were more pronounced for the contiguous sounds. Across all three experiments, the effects of relative level were more pronounced for attenuation. In addition, the effects of relative level showed a dependence on the position of the change in level, with opposite direction for attenuation compared to amplification. Some of the results are in accordance with explanations based on masking effects on auditory intensity resolution.

The Role of the Medial Olivocochlear Reflex in Psychophysical Masking and Intensity Resolution in Humans: A Review

This review addresses the putative role of the medial olivocochlear (MOC) reflex on psychophysical masking and intensity resolution in humans. A framework for interpreting psychophysical results in terms of the expected influenced of the MOC reflex is introduced. This framework is used to review the effects of a precursor or contralateral acoustic stimulation on 1) simultaneous masking of brief tones, 2) behavioral estimates of cochlear gain and frequency resolution in forward masking, 3) the build-up and decay of forward masking, and 4) measures of intensity resolution. Support, or lack thereof, for a role of the MOC reflex in psychophysical perception is discussed in terms of studies on estimates of MOC strength from otoacoustic emissions and the effects of resection of the olivocochlear bundle in patients with vestibular neurectomy. Novel, innovative approaches are needed to resolve the dissatisfying conclusion that current results are unable to definitively confirm or refute the role of the MOC reflex in masking and intensity resolution.

Comparison of the quality of the result of digitising panoramic analogue films using transmission and reflection scanner mode with direct digital imaging standard

Introduction: The use of panoramic x-ray radiographs with analogue film negatives is still widely used. Contrast differences in the radiograph are determined by the level of light transmitted from the viewer to the film negative and visual perception of the radiologist, which can cause differences and errors of interpretation. This study was aimed to compare the quality of scanners produced by the transmission and reflection modes objectively with direct digital imaging standard. Methods: This study used a descriptive comparative design with purposive sampling method. Radiographic analysis was conducted towards 30 analogue radiographs of Radiology laboratory of Universitas Padjadjaran Dental Hospital. Digitisation was performed using a scanner with setting modes (reflection and transmission, 8-bit intensity resolution and spatial resolution of 800 dpi). Digitising the negative radiographs of analogue films into digital radiographs will get a range of percentage pixels. Histogram of radiographs with a percentage of pixels in the grey level range 0 - 64 exceeds 50%, including "under-exposed", in the grey level range 192 - 255 exceeding 50%, including "over-exposed". The evaluation was carried out to observe the radiograph exposure homogeneity by dividing the radiograph into 4 parts. Each part was calculated as the mean pixel value; then the standard deviation was searched for the four mean values (STDMI - standard deviation mean intensity) determined the homogeneity. Results: Digitising type of radiograph reflection was included under-exposed because the percentage of pixels in the grey level range 0 - 64 was 86.94%. STDMI consecutive reflection = 8.03, transmission = 18.05, direct digital imaging = 20.86. Conclusion: Digitisation with scanner transmission mode is the best result objectively because it approaches the quality value of direct digital imaging standard.Keywords: Objective quality, homogeneity, reflection, transmission

A new electron-multiplier-tube-based beam monitor for muon monitoring at the T2K experiment

Muon beam monitoring is indispensable for indirectly monitoring accelerator-produced neutrino beams in real time. Though Si photodiodes and ionization chambers have been successfully used as muon monitors at the T2K experiment, sensors that are more radiation tolerant are desired for future operation. We have investigated the electron-multiplier tube (EMT) as a new sensor for muon monitoring. Secondary electrons produced by the passage of muons at dynodes are multiplied in the tube and produce signal. Two prototype detectors were installed at the T2K muon monitor location, and various EMT properties were studied based on in situ data taken with the T2K muon beam. The signal size is as expected based on calculation, and the EMTs show a sufficiently fast time response for bunch-by-bunch beam monitoring. The spill-by-spill intensity resolution is 0.4%, better than the required value (1%). Signal linearity within $\pm$1% is achieved at proton beam powers up to 460 kW (with +250 kA focusing horn operation). A gradual signal decrease was observed during the initial exposure, due to the stabilization of dynode materials, before the response became stable within $\pm$1%. This work demonstrates that EMTs are a good candidate for future muon monitoring at T2K, and may also have other more general applications.

Geography and International Studies: The Foundations

The discipline of geography is built around four key concepts—environment, place, space, and scale—that form a matrix for exploring and appreciating many aspects of contemporary society. The environment is the ultimate source of human sustenance; people have created places to realize that potential; and a spatial structure—nodes, routes, surfaces and bounded territories—has been erected within which human interactions are organised.The relationships between human societies and their environments—now very much changed from their pre-human “natural” state—involve competition for and conflicts over resources, of increasing intensity. Resolution of all but the smallest scale of those conflicts requires a body that is independent of the actors involved and can ensure that agreements are reached and then implemented. Such a body is the state, a territorially bounded apparatus that, through the operation of territoriality strategies, can ensure conflict resolution among its citizenry and thereby resolve environmental problems.Many of those problems—the most severe being global climate change resulting from anthropomorphically induced global warming—are not contained, and cannot be contained, within an individual state’s territory, however. Tackling them requires inter-state co-operation, at a global scale, but the absence of a super-national body with the power to require actions by individual states is a major constraint to problem resolution.

A Modified Harris Corner Detection for Breast IR Image

Harris corner detectors, which depend on strong invariance and a local autocorrelation function, display poor detection performance for infrared (IR) images with low contrast and nonobvious edges. In addition, feature points detected by Harris corner detectors are clustered due to the numerous nonlocal maxima. This paper proposes a modified Harris corner detector that includes two unique steps for processing IR images in order to overcome the aforementioned problems. Image contrast enhancement based on a generalized form of histogram equalization (HE) combined with adjusting the intensity resolution causes false contours on IR images to acquire obvious edges. Adaptive nonmaximal suppression based on eliminating neighboring pixels avoids the clustered features. Preliminary results show that the proposed method can solve the clustering problem and successfully identify the representative feature points of IR breast images.