Assessing the effectiveness of multi-touch interfaces for DP operation

Navigating a vessel using dynamic positioning (DP) systems close to offshore installations is a challenge. The operator's only possibility of manipulating the system is through its interface, which can be categorized as the physical appearance of the equipment and the visualization of the system. Are there possibilities of interaction between the operator and the system that can reduce strain and cognitive load during DP operations? Can parts of the system (e.g. displays) be physically brought closer to the user to enhance the feeling of control when operating the system? Can these changes make DP operations more efficient and safe? These questions inspired this research project, which investigates the use of multi-touch and hand gestures known from consumer products to directly manipulate the visualization of a vessel in the 3D scene of a DP system. Usability methodologies and evaluation techniques that are widely used in consumer market research were used to investigate how these interaction techniques, which are new to the maritime domain, could make interaction with the DP system more efficient and transparent both during standard and safety-critical operations. After investigating which gestures felt natural to use by running user tests with a paper prototype, the gestures were implemented into a Rolls-Royce DP system and tested in a static environment. The results showed that the test participants performed significantly faster using direct gesture manipulation compared to using traditional button/menu interaction. To support the results from these tests, further tests were carried out. The purpose is to investigate how gestures are performed in a moving environment, using a motion platform to simulate rough sea conditions. The key results and lessons learned from a collection of four user experiments, together with a discussion of the choice of evaluation techniques will be discussed in this paper

Do agonistic behaviours bias baited remote underwater video surveys of fish?

Marine environments require monitoring to determine the effects of impacts such as climate change, coastal development and pollution and also to assess the effectiveness of conservation measures. Marine protected areas (MPAs) are being established globally and require periodic monitoring to determine whether their objectives are being met. Baited underwater video systems are becoming a popular method for monitoring change within protected fish populations, because they are less damaging to habitats than bottom trawling and allow for more statistical powerful comparisons to determine spatial and temporal patterns in the relative abundances, lengths and biomass of demersal and pelagic fishes. However, much remains uncertain about how interactions between the fish and bait and between the fish themselves affect the results obtained. Agonistic behaviours are frequently observed around the bait of the camera and potentially bias fish density estimates by altering the number and size classes seen at cameras. Here we counted the number of agonistic behaviours between pink snappers (Pagrus auratus), the size of fish involved and whether the fish left the field of view following such behaviours. The study consisted of 20 baited underwater video deployments inside a New Zealand marine reserve and 20 in adjacent open areas. We observed a significant relationship between the peak number of fish observed at the camera and the total number of agonistic behaviours, as well as the number of both aggressor and subordinate fish leaving the camera field of view following interactions. The slope of the latter relationship and thus the absolute numbers of fish leaving were higher for subordinate fish. As subordinates were significantly smaller than aggressors, the apparent size frequency distribution is likely skewed away from smaller size classes. The staying time of the fish and thus the maximum number of fish present at the camera will be reduced by agonistic behaviours and the absolute magnitude of this effect appears to be greater at high fish densities. Our results suggest that an overall effect of these phenomena is to underestimate the differences in abundance between MPAs and open areas, but also to overestimate differences in average size

Pushing the Limits: Testing, Magnetometry and Ontario Lithic Scatters

Lithic scatters, small ephemeral clusters of stone artifacts on cultivated surfaces, lie on the periphery of archaeology. These sites are often too ephemeral to be fully understood through standardized fieldwork methodologies mandated in Ontario CRM archaeology and yet, they are widely regarded as worth documenting with hundreds now recorded. In this thesis, it is argued that what are small artifact scatters on the surface can belie more complex subsurface finds of significant cultural and historical value. As such, there is a need to reconsider the approaches made to the investigation of these sites. Geophysical techniques applied early in a scatter’s investigation, particularly magnetometry, have the ability to facilitate the extraction of more pertinent data about past peoples and their activities from such sites. Archaeological work was carried out at two sites near Kitchener, Ontario, in order to evaluate whether surface and excavated artifact densities correlate with preserved subsurface cultural deposits. This work also included a direct and positive attempt at one of the sites to test the utility of magnetometry in this process

Methodology for Sampling Women at High Maternal Risk in Administrative Data

Background: In population level studies, the conventional practice of categorizing women into low and high maternal risk samples relies upon ascertaining the presence of various comorbid conditions in administrative data. Two problems with the conventional method include variability in the recommended comorbidities to consider and inability to distinguish between maternal and fetal risks. High maternal risk sample selection may be improved by using the Obstetric Comorbidity Index (OCI), a system of risk scoring based on weighting comorbidities associated with maternal end organ damage. The purpose of this study was to compare the net benefit of using OCI risk scoring vs the conventional risk identification method to identify a sample of women at high maternal risk in administrative data. Methods: This was a net benefit analysis using linked delivery hospitalization discharge and vital records data for women experiencing singleton births in Georgia from 2008 to 2012. We compared the value identifying a sample of women at high maternal risk using the OCI score to the conventional method of dichotomous identification of any comorbidities. Value was measured by the ability to select a sample of women designated as high maternal risk who experienced severe maternal morbidity or mortality. Results: The high maternal risk sample created with the OCI had a small but positive net benefit (+ 0.6), while the conventionally derived sample had a negative net benefit indicating the sample selection performed worse than identifying no woman as high maternal risk. Conclusions: The OCI can be used to select women at high maternal risk in administrative data. The OCI provides a consistent method of identification for women at risk of maternal morbidity and mortality and avoids confounding all obstetric risk factors with specific maternal risk factors. Using the OCI may help reduce misclassification as high maternal risk and improve the consistency in identifying women at high maternal risk in administrative data

Design concepts for bioreactors in space

Microbial food sources are becoming viable and more efficient alternatives to conventional food sources especially in the context of Closed Ecological Life Support Systems (CELSS) in space habitats. Since bioreactor designs for terrestrial operation will not readily apply to conditions of microgravity, there is an urgent need to learn about the differences. These differences cannot be easily estimated due to the complex nature of the mass transport and mixing mechanisms in fermenters. Therefore, a systematic and expeditious experimental program must be undertaken to obtain the engineering data necessary to lay down the foundations of designing bioreactors for microgravity. Two bioreactor design concepts presented represent two dissimilar approaches to grappling with the absence of gravity in space habitats and deserve to be tested for adoption as important components of the life support function aboard spacecrafts, space stations and other extra-terrestrial habitats

Review of SIS Experimental Results on Strangeness

>A review of meson emission in heavy ion collisions at incident energies around 1 -- 2 $A\cdot$GeV is presented. It is shown how the shape of the spectra and the various particle yields vary with system size, with centrality and with incident energy. A statistical model assuming thermal and chemical equilibrium and exact strangeness conservation (i.e. strangeness conservation per collision) explains most of the observed features. Emphasis is put onto the study of $K^+$ and $K^-$ emission. In the framework of this statistical model it is shown that the experimentally observed equality of $K^+$ and $K^-$ rates at threshold corrected energies $\sqrt{s} - \sqrt{s_{th}}$ is due to a crossing of two excitation functions. Furthermore, the independence of the $K^+$ to $K^-$ ratio on the number of participating nucleons observed between 1 and 10 $A\cdot$GeV is consistent with this model. The observed flow effects are beyond the scope of this model.Comment: 10 pages, 9 figures, Strangeness 2000, V International Conference on Strangeness in Quark Matter, July, 2000, Berkeley, Californi

Multiplexed communication over a high-speed quantum channel

In quantum information systems it is of particular interest to consider the best way in which to use the non-classical resources consumed by that system. Quantum communication protocols are integral to quantum information systems and are amongst the most promising near-term applications of quantum information science. Here we show that a multiplexed, digital quantum communications system supported by comb of vacuum squeezing has a greater channel capacity per photon than a source of broadband squeezing with the same analogue bandwidth. We report on the time-resolved, simultaneous observation of the first dozen teeth in a 2.4 GHz comb of vacuum squeezing produced by a sub-threshold OPO, as required for such a quantum communications channel. We also demonstrate multiplexed communication on that channel