85,487 research outputs found
A comprehensive investigation into the hydrodynamic and capture/retention performance of a gross pollutant trap
A novel and comprehensive testing approach to examine the performance of gross pollutant traps (GPTs) was developed. A proprietary GPT with internal screens for capturing gross pollutantsâorganic matter and anthropogenic litterâwas used as a case study. This work is the first investigation of its kind and provides valuable practical information for the design, selection and operation of GPTs and also the management of street waste in an urban environment. It used a combination of physical and theoretical models to examine in detail the hydrodynamic and capture/retention characteristics of the GPT. The results showed that the GPT operated efficiently until at least 68% of the screens were blocked, particularly at high flow rates. At lower flow rates, the high capture/retention performance trend was reversed. It was also found that a raised inlet GPT offered a better capture/retention performance. This finding indicates that cleaning operations could be more effectively planned in conjunction with the deterioration in GPTâs capture/retention performance
Can small be beautiful? assessing image resolution requirements for mobile TV
Mobile TV services are now being offered in several countries, but for cost reasons, most of these services offer material directly recoded for mobile consumption (i.e. without additional editing). The experiment reported in this paper, aims to assess the image resolution and bitrate requirements for displaying this type of material on mobile devices. The study, with 128 participants, examined responses to four different image resolutions, seven video encoding bitrates, two audio bitrates and four content types. The results show that acceptability is significantly lower for images smaller than 168Ă126, regardless of content type. The effect is more pronounced when bandwidth is abundant, and is due to important detail being lost in the smaller screens. In contrast to previous studies, participants are more likely to rate image quality as unacceptable when the audio quality is high
Pervasive and standalone computing: The perceptual effects of variable multimedia quality.
The introduction of multimedia on pervasive and mobile communication devices raises a number of perceptual quality issues, however, limited work has been done examining the 3-way interaction between use of equipment, quality of perception and quality of service. Our work measures levels of informational transfer (objective) and user satisfaction (subjective)when users are presented with multimedia video clips at three different frame rates, using four different display devices, simulating variation in participant mobility. Our results will show that variation in frame-rate does not impact a userâs level of information assimilation, however, does impact a usersâ perception of multimedia video âqualityâ. Additionally, increased visual immersion can be used to increase transfer of video information, but can negatively affect the usersâ perception of âqualityâ. Finally, we illustrate the significant affect of clip-content on the transfer of video, audio and textual information, placing into doubt the use of purely objective quality definitions when considering multimedia
presentations
Population screening for colorectal cancer means getting FIT:the past, present, and future of colorectal cancer screening using the fecal immunochemical test for hemoglobin (FIT)
Fecal immunochemical tests for hemoglobin (FIT) are changing the manner in which colorectal cancer (CRC) is screened. Although these tests are being performed worldwide, why is this test different from its predecessors? What evidence supports its adoption? How can this evidence best be used? This review addresses these questions and provides an understanding of FIT theory and practices to expedite international efforts to implement the use of FIT in CRC screening
Hidden Pursuits: Evaluating Gaze-selection via Pursuits when the Stimuli's Trajectory is Partially Hidden
The idea behind gaze interaction using Pursuits is to leverage the human's smooth pursuit eye movements performed when following moving targets. However, humans can also anticipate where a moving target would reappear if it temporarily hides from their view. In this work, we investigate how well users can select targets using Pursuits in cases where the target's trajectory is partially invisible (HiddenPursuits): e.g., can users select a moving target that temporarily hides behind another object? Although HiddenPursuits was not studied in the context of interaction before, understanding how well users can perform HiddenPursuits presents numerous opportunities, particularly for small interfaces where a target's trajectory can cover area outside of the screen. We found that users can still select targets quickly via Pursuits even if their trajectory is up to 50% hidden, and at the expense of longer selection times when the hidden portion is larger. We discuss how gaze-based interfaces can leverage HiddenPursuits for an improved user experience
Role of fuel chemical properties on combustor radiative heat load
In an attempt to rigorously study the fuel chemical property influence on combustor radiative heat load, United Technologies Research Center (UTRC) has conducted an experimental program using 25 test fuels. The burner was a 12.7-cm dia cylindrical device fueled by a single pressure-atomizing injector. Fuel physical properties were de-emphasized by selecting injectors which produced high-atomized, and hence rapidly-vaporizing sprays. The fuels were specified to cover the following wide ranges of chemical properties; hydrogen, 9.1 to 15- (wt) pct; total aromatics, 0 to 100 (vol) pct; and naphthalene, 0 to 30 (vol) pct. They included standard fuels, specialty products and fuel blends. Fuel naphthalene content exhibited the strongest influence on radiation of the chemical properties investigated. Smoke point was a good global indicator of radiation severity
Examining the role of smart TVs and VR HMDs in synchronous at-a-distance media consumption
This article examines synchronous at-a-distance media consumption from two perspectives: How it can be facilitated using existing consumer displays (through TVs combined with smartphones), and imminently available consumer displays (through virtual reality (VR) HMDs combined with RGBD sensing). First, we discuss results from an initial evaluation of a synchronous shared at-a-distance smart TV system, CastAway. Through week-long in-home deployments with five couples, we gain formative insights into the adoption and usage of at-a-distance media consumption and how couples communicated during said consumption. We then examine how the imminent availability and potential adoption of consumer VR HMDs could affect preferences toward how synchronous at-a-distance media consumption is conducted, in a laboratory study of 12 pairs, by enhancing media immersion and supporting embodied telepresence for communication. Finally, we discuss the implications these studies have for the near-future of consumer synchronous at-a-distance media consumption. When combined, these studies begin to explore a design space regarding the varying ways in which at-a-distance media consumption can be supported and experienced (through music, TV content, augmenting existing TV content for immersion, and immersive VR content), what factors might influence usage and adoption and the implications for supporting communication and telepresence during media consumption
A user perspective of quality of service in m-commerce
This is the post-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2004 Springer VerlagIn an m-commerce setting, the underlying communication system will have to provide a Quality of Service (QoS) in the presence of two competing factorsânetwork bandwidth and, as the pressure to add value to the business-to-consumer (B2C) shopping experience by integrating multimedia applications grows, increasing data sizes. In this paper, developments in the area of QoS-dependent multimedia perceptual quality are reviewed and are integrated with recent work focusing on QoS for e-commerce. Based on previously identified user perceptual tolerance to varying multimedia QoS, we show that enhancing the m-commerce B2C user experience with multimedia, far from being an idealised scenario, is in fact feasible if perceptual considerations are employed
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