An interface to virtual environments for people who are blind using Wii technology - mental models and navigation

Accessible games, both for serious and for entertainment purposes, would allow inclusion and participation for those with disabilities. Research into the development of accessible games, and accessible virtual environments, is discussed. Research into accessible Virtual Environments has demonstrated great potential for allowing people who are blind to explore new spaces, reducing their reliance on guides, and aiding development of more efficient spatial maps and strategies. Importantly, Lahav and Mioduser (2005, 2008) have demonstrated that, when exploring virtual spaces, people who are blind use more and different strategies than when exploring real physical spaces, and develop relatively accurate spatial representations of them. The present paper describes the design, development and evaluation of a system in which a virtual environment may be explored by people who are blind using Nintendo Wii devices, with auditory and haptic feedback. The nature of the various types of feedback is considered, with the aim of creating an intuitive and usable system. Using Wii technology has many advantages, not least of which are that it is mainstream, readily available and cheap. The potential of the system for exploration and navigation is demonstrated. Results strongly support the possibilities of the system for facilitating and supporting the construction of cognitive maps and spatial strategies. Intelligent support is discussed. Systems such as the present one will facilitate the development of accessible games, and thus enable Universal Design and accessible interactive technology to become more accepted and widespread

Using Wii technology to explore real spaces via virtual environments for people who are blind

Purpose - Virtual environments (VEs) that represent real spaces (RSs) give people who are blind the opportunity to build a cognitive map in advance that they will be able to use when arriving at the RS. Design - In this research study Nintendo Wii based technology was used for exploring VEs via the Wiici application. The Wiimote allows the user to interact with VEs by simulating walking and scanning the space. Finding - By getting haptic and auditory feedback the user learned to explore new spaces. We examined the participants' abilities to explore new simple and complex places, construct a cognitive map, and perform orientation tasks in the RS. Originality – To our knowledge, this finding presents the first virtual environment for people who are blind that allow the participants to scan the environment and by this to construct map model spatial representations

Finding the way forward for forensic science in the US:a commentary on the PCAST report

A recent report by the US President’s Council of Advisors on Science and Technology (PCAST) [1] has made a number of recommendations for the future development of forensic science. Whereas we all agree that there is much need for change, we find that the PCAST report recommendations are founded on serious misunderstandings. We explain the traditional forensic paradigms of match and identification and the more recent foundation of the logical approach to evidence evaluation. This forms the groundwork for exposing many sources of confusion in the PCAST report. We explain how the notion of treating the scientist as a black box and the assignment of evidential weight through error rates is overly restrictive and misconceived. Our own view sees inferential logic, the development of calibrated knowledge and understanding of scientists as the core of the advance of the profession

Proceedings of the 24th annual Central Plains irrigation conference

Presented at Proceedings of the 24th annual Central Plains irrigation conference held on February 21-22 in Colby, Kansas.Includes bibliographical references

Comparison of soil water sensing methods for irrigation management and research

Presented at the 2007 Central Plains irrigation conference on February 27-28 in Kearney, Nebraska.Includes bibliographical references.As irrigation water resources decrease and deficit irrigation becomes more common across the Great Plains, greater accuracy in irrigation scheduling will be required. With deficit irrigation a smaller amount of soil water is held in reserve and there is less margin for error. Researchers investigating deficit irrigation practices and developing management practices must also have accurate measures of soil water content - in fact, the two go hand in hand. New management practices for deficit irrigation will require more accurate assessments of soil water content if success is to be ensured. This study compared several commercial soil water sensing systems, four of them based on the electromagnetic (EM) properties of soil as influenced by soil water content, versus the venerable neutron moisture meter (NMM), which is based on the slowing of neutrons by soil water. While performance varied widely, the EM sensors were all less precise and less accurate in the field than was the NMM. Variation in water contents from one measurement location to the next was much greater for the EM sensors and was so large that these sensors are not useful for determining the amount of water to apply. The NMM is still the only sensor that is suitable for irrigation research. However, the NMM is not practical for on-farm irrigation management due to cost and regulatory issues. Unfortunately, our studies indicate that the EM sensors are not useful for irrigation management due to inaccuracy and variability. A new generation of EM sensors should be developed to overcome the problems of those currently available. In the meantime, tensiometers, electrical resistance sensors and soil probes may fill the gap for irrigation management based on soil water sensing. However, many farmers are successfully using irrigation scheduling based on crop water use estimates from weather station networks and reference ET calculations. When used in conjunction with direct field soil water observations to avoid over irrigation, the ET network approach has proved useful in maximizing yields

Identifying Advantages and Disadvantages of Variable Rate Irrigation – An Updated Review

Variable rate irrigation (VRI) sprinklers on mechanical move irrigation systems (center pivot or lateral move) have been commercially available since 2004. Although the number of VRI, zone or individual sprinkler, systems adopted to date is lower than expected there is a continued interest to harness this technology, especially when climate variability, regulatory nutrient management, water conservation policies, and declining water for agriculture compound the challenges involved for irrigated crop production. This article reviews the potential advantages and potential disadvantages of VRI technology for moving sprinklers, provides updated examples on such aspects, suggests a protocol for designing and implementing VRI technology and reports on the recent advancements. The advantages of VRI technology are demonstrated in the areas of agronomic improvement, greater economic returns, environmental protection and risk management, while the main drawbacks to VRI technology include the complexity to successfully implement the technology and the lack of evidence that it assures better performance in net profit or water savings. Although advances have been made in VRI technologies, its penetration into the market will continue to depend on tangible and perceived benefits by producers

USCID fourth international conference

Presented at the Role of irrigation and drainage in a sustainable future: USCID fourth international conference on irrigation and drainage on October 3-6, 2007 in Sacramento, California.Includes bibliographical references.Deficit irrigation commonly is used in regions with reduced or limited irrigation capacity to increase water use efficiency (WUE). This research measured winter wheat (Triticum aestivum L.) and sorghum (Sorghum bicolor L. Moench) water use (ET) and yields so WUE could be determined. Two precision weighing lysimeters were used to accurately measure the crop ET from fully irrigated (FULL) fields and deficit irrigated (DI) fields. The DI wheat was an irrigation cutoff at the jointing growth stage as might be used if available irrigation water was being shifted to summer crops while the sorghum DI used a reduced irrigation rate (~50% FULL irrigation) as might occur with a lower irrigation capacity. Both crops were irrigated by a lateral-move sprinkler system at Bushland, Texas. Wheat ET was decreased by 20% from 849 to 677 mm with a 76% decline in irrigation. Sorghum ET decreased 10% from 621 mm to 560 mm with a 48% decline in irrigation. WUE of sorghum for both grain and dry matter increased slightly with DI but seed mass, and harvest index were unaffected. DI irrigated wheat extracted soil water to a depth of 1.7 m in the Pullman soil with some apparent root extraction to the 2.3-m depth. Sorghum extracted soil water mainly above 1.2 m in the Pullman soil profile if well watered, but DI sorghum extracted soil water to 1.7 m. Sprinkler DI of sorghum beginning with a nearly full soil water content profile permitted the crop to better exploit the soil profile water and minimize soil water deficit effects on crop yield in a year with typical summer rainfall for Bushland (~210 mm) such that yield was not reduced by DI. Cutting off winter wheat irrigation in early spring with a near full soil water profile at jointing, permitted the wheat crop to fully exploit the soil water reservoir when rainfall was normal

A response to “Likelihood ratio as weight of evidence: a closer look” by Lund and Iyer

Recently, Lund and Iyer (L&I) raised an argument regarding the use of likelihood ratios in court. In our view, their argument is based on a lack of understanding of the paradigm. L&I argue that the decision maker should not accept the expert’s likelihood ratio without further consideration. This is agreed by all parties. In normal practice, there is often considerable and proper exploration in court of the basis for any probabilistic statement. We conclude that L&I argue against a practice that does not exist and which no one advocates. Further we conclude that the most informative summary of evidential weight is the likelihood ratio. We state that this is the summary that should be presented to a court in every scientific assessment of evidential weight with supporting information about how it was constructed and on what it was based

Northern Texas High Plains

Presented at the 2002 USCID/EWRI conference, Energy, climate, environment and water - issues and opportunities for irrigation and drainage on July 9-12 in San Luis Obispo, California.Includes bibliographical references.Cotton (Gossypium hirsutum L.) is beginning to be produced on the Northern Texas High Plains as a lower water-requiring crop while producing an acceptable profit. Cotton is a warm season, perennial species produced like an annual yet it requires a delicate balance of water and water deficit controls to most effectively produce high yields in this thermally limited environment. This study measured the water use of cotton in near-fully irrigated, deficiently irrigated, and dryland regimes in a Northern Texas High Plains environment, which has a shortened cotton producing season, using precision weighing lysimeters in 2000 and 2001. The irrigated regimes were irrigated with a lateral-move sprinkler system. The water use data were used to develop crop coefficient data and compared with the FAO-56 method for estimating crop water use. Cotton yield, water use, and water use efficiency was found to be as good in this region as other more noted cotton regions. FAO-56 ET prediction procedures performed better for the more fully irrigated treatments in this environment