The workload implications of haptic displays in multi-display environments such as the cockpit: Dual-task interference of within-sense haptic inputs (tactile/proprioceptive) and between-sense inputs (tactile/proprioceptive/auditory/visual)

Visual workload demand within the cockpit is reaching saturation, whereas the haptic sense (proprioceptive and tactile sensation) is relatively untapped, despite studies suggesting the benefits of haptic displays. MRT suggests that inputs from haptic displays will not interfere with inputs from visual or auditory displays. MRT is based on the premise that multisensory integration occurs only after unisensory processing. However, recent neuroscientific findings suggest that the distinction between unisensory versus multisensory processing is much more blurred than previously thought. This programme of work had the following two research objectives: 1. To examine whether multiple haptic inputs can be processed at the same time without performance decrement - Study One 2. To examine whether haptic inputs can be processed at the same time as visual or auditory inputs without performance decrement - Study Two In Study One participants performed dual-tasks, consisting of same-sense tasks (tactile or proprioceptive) or different-sense tasks (tactile and proprioceptive). These tasks also varied in terms of processing code, in line with MRT. The results found significantly more performance decrement for the same-sense dual-tasks than for the different-sense dual-tasks, in accordance with MRT, suggesting that performance will suffer if two haptic displays of the same type are used concurrently. An adjustment to the MRT model is suggested to incorporate these results. In Study Two, participants performed different-sense dual-tasks, consisting of auditory or visual tasks with tactile or proprioceptive tasks. The tasks also varied in terms of processing code. Contrary to MRT, the results found that when processing code was different, there was significant performance decrement for all of the dual-tasks, but not when processing code was the same. These results reveal an exception to two key MRT rules, the sensory resource rule and the processing code rule. It is suggested that MRT may be oversimplistic and other factors highlighted by recent neuroscientific research should be taken into account in theories of dual-task performance

Has the Usage of Precision Agriculture Technologies Actually Led to Increased Profits for Nebraska Producers?

An ever-increasing global demand for food, coupled with increasingly volatile commodity prices have charged producers with the task of becoming more efficient. As such, technologies aimed at producing more with less are continually being developed and marketed to producers. However, whether or not these expensive new technologies have resulted in improved profitability is still unknown, as the vast majority of studies showing their impact on profitability have been performed using hypothetical farms and simulations. These studies have shown the potential for increases in profitability from use, but their impact in the real world is still uncertain. This project uses various fixed-effect panel data models to examine the realized economic impact of using precision agriculture technologies amongst a sample of producers across Nebraska using financial data from 1995-2014. Results of the study show the existence of a strong, positive relationship between number of technologies used and net farm income, indicating that precision agriculture use is associated with higher profitability. However, whether use is driving profitability or profitability is driving use remains somewhat unclear. Pre-and-post analysis among users of the technologies suggest profitability has in fact increased from use, but the result is not statistically significant. This may be a consequence of mixed results among users, with many factors influencing the level of benefit achievable from use. Nonetheless, an obvious learning effect exists for users, with profitability increasing more as experience with the technologies increases. This would be expected due to the need to produce data regarding within-field variability on which to capitalize, along with the investment in learning the ideal use of these relatively complicated technologies. Overall, it is obvious that further research regarding the impact of these technologies is of great relevance. Advisor: Bradley D. Lubbe

Body water compartments during bed rest: Evaluation of analytical methods

Nine healthy young men were studied to determine the reproducibility and interchangeability of the use of radio-iodinated human serum albumin and Evans Blue dye for estimating plasma volume, sodium bromide for extracellular fluid volume, and deuterium oxide for total body water volume. All subjects were tested in a semibasal condition and allowed to rest for at least 30 min. after arriving at the laboratory. The results indicate that there was uniform distribution of I131 and Evans Blue dye 10 min. after injection and of NaBr and D2O 3 hours after oral ingestion; the buildup of residual tracer did not interfere appreciably with the measurement of either or Evans Blue spaces when they are administered at equal intervals, and the buildup of background tracer after ingestion of NaBr and D2O once per week for three consecutive weeks did not affect the accuracy of the measurement. It was found that I131 and Evans Blue may be used interchangeably for estimating plasma volume; for estimating bromide and D2O spaces, one 3-hour equilibrium blood sample gives results similar to the extrapolation of multiple samples

Ichthyological Bulletin; No. 33

The eel family Congridae is now known to be represented in the western Indian Ocean (here regarded to be west of 60 E. from and including the Red Sea, to Cape Point) by 11 genera and 19 species as well as at least five distinct larval forms which have not yet been identified. More than half of these species inhabit the shallow and offshore waters of the tropical western Indian Ocean. The remainder are known only from cool-temperate waters off the Cape, with one deep-water Atlantic species and one Mediterranean species also present in this area. Considerable additions to this fauna can be expected as the deep waters off the east coast are more fully sampled. Congrina wallacei sp. nov., de- scribed here from 260-270 fathoms off southern Mozambique and Durban, has rather large teeth on the jaws, a long snout and about 168 vertebrae. At least one species spawns off the Cape, but the majority probably do so over the western edge of the oceanic basins north and south of Madagascar. The shallow-water species show strong affinities with the tropical and cool-temperate Indo-Pacific.Rhodes University Libraries (Digitisation

Factors Influencing Producer Propensity for Data Sharing & Opinions Regarding Precision Agriculture and Big Farm Data

With its tremendous success by notable companies in varying industries, “big data” has become a hard-to-miss phrase and many believe its usage in agriculture is the future of the industry. However, the potential benefits of using big data come with just as many challenges, ranging from not knowing how to make use of it, to the debate over who owns and has access to it. A survey asking for producers’ opinions on precision agriculture technologies and big farm data was distributed to a sample of agricultural producers across Nebraska. A Poisson regression was used to determine the factors influencing propensity for data sharing and frequency tables were used to examine producer opinions on the topic. Older producers and those not using irrigation in their operation were found to have a lower propensity for sharing their farm-level data. In general, producer understanding of what big data is and how to use it is lacking. Precision agriculture users mostly believe they have seen increases in profits and efficiency due to use, but producers expressed concern over not knowing how to interpret and make use of the data as well as the overall affordability and cost of the technologies producing the data

Factors Influencing the Adoption of Precision Agriculture Technologies by Nebraska Producers

An ever-increasing world population and increasingly-volatile commodity prices have charged producers with the task of becoming more efficient. To combat this, precision agriculture technologies aimed at increasing production efficiency are continually being developed, but their adoption is not yet widespread. A survey regarding the usage of these technologies was distributed to a sample of row crop producers across the state of Nebraska and a Poisson regression was used to determine the factors influencing adoption. Results of the study indicate that larger, more tech-savvy producers and those using irrigation are more likely to adopt a higher number of precision agriculture technologies, while operator age and gross farm income were found to be non-influential factors

Solar concentrator technology development for space based applications, volume 2

Thermoelectric conversion using a radio-isotope heat source has been used where outer planetary space craft are too far away for absorbing significant solar energy. Solar dynamic power (SDP) conversion is one technology that offers advantages for applications within the inner planet region. Since SDP conversion efficiency can be 2 to 3 times higher than photovoltaic, the collecting surfaces are much reduced in area and therefore lighter. This becomes an advantage in allocating more weight to launched payloads. A second advantage results for low earth orbit applications. The reduced area results in lower drag forces on the spacecraft and requires less reboost propellant to maintain orbit. A third advantage occurs because of the sun-to-shade cycling while in earth orbit. Photovoltaic systems require batteries to store energy for use when in the shade, and battery life for periods of 10 to 15 years is not presently achievable. For these reasons the Solar Dynamics and Thermal Systems Branch at NASA LeRC has funded work in developing SDP systems. The generic SDP system uses a large parabolic solar concentrator to focus solar energy onto a power conversion device. The concentrators are large areas and must therefore be efficient and have low specific weights. Yet these surfaces must be precise and capable of being stowed in a launch vehicle and then deployed and sometimes unfurled in space. There are significant technical challenges in engineering such structures, and considerable investigation has been made to date. This is the second of two volumes reporting on the research done by the Advanced Manufacturing Center at Cleveland State University to assist NASA LeRC in evaluating this technology. This volume includes the appendices of selected data sets, drawings, and procedures. The objective of the grant was to restore the solar concentrator development technology of the 1960s while improving it with advances that have occurred since then. This report summarizes the work done from January 1989 through December 1991