Shane Pinder

The reliability of isoinertial force–velocity–power profiling and maximal strength assessment in youth

The purpose of this study was to quantify the inter-session reliability of force–velocity–power profiling and estimated maximal strength in youth. Thirty-six males (11–15 years old) performed a ballistic supine leg press test at five randomized loads (80%, 100%, 120%, 140%, and 160% body mass) on three separate occasions. Peak and mean force, power, velocity, and peak displacement were collected with a linear position transducer attached to the weight stack. Mean values at each load were used to calculate different regression lines and estimate maximal strength, force, velocity, and power. All variables were found reliable (change in the mean [CIM] = − 1 to 14%; coefficient of variation [CV] = 3–18%; intraclass correlation coefficient [ICC] = 0.74–0.99), but were likely to benefit from a familiarization, apart from the unreliable maximal force/velocity ratio (CIM = 0–3%; CV = 23–25%; ICC = 0.35–0.54) and load at maximal power (CIM = − 1 to 2%; CV = 10–13%; ICC = 0.26–0.61). Isoinertial force–velocity–power profiling and maximal strength in youth can be assessed after a familiarization session. Such profiling may provide valuable insight into neuromuscular capabilities during growth and maturation and may be used to monitor specific training adaptations.

Application of the global Positioning System in determination of vehicular acceleration

Aircraft landing and takeoff performance monitoring is an area of research aimed at improving the information available to the pilot for decision making during takeoff or landing. A system capable of instantaneously determining the stopping distance of an aircraft could form an integral component of a monitoring system. Particularly difficult to quantify is the frictional coefficient between the runway and the aircraft tires, should such a measurement be necessary. In secluded far-northern regions, where a monitoring system would be particularly useful given adverse weather, few airports are equipped to attempt frictional measurements. In such instances a monitoring system would need to be totally self-contained and able to determine aircraft ground speed, acceleration, and position relative to the end of the runway. Prediction of the aircrafts location at rest is then possible. It is proposed that the Global Positioning System (GPS) be used to determine aircraft acceleration, ground speed, and position relative to the end of the runway. A practical evaluation of the feasibility of this proposal showed clear superiority of a GPS-derived acceleration over a more traditional method employing accelerometers. Advantages of the GPS-derived measurement include a modest noise level, insusceptibility to gravity and temperature-influenced variations, and far simplified mounting criteria.

Mobility interfaces for the visually impaired: what's missing?

Individuals with visual impairments must rely on information from their other senses to provide them with obstacle preview. Although the long cane has become the most common primary device for detecting obstacles on the ground, other systems have gained acceptance by cane users who already have a high degree of travel ability as secondary mobility devices to detect obstacles that are not ground-based. Echolocation, on the other hand, has been a method of localisation in the past that enables a traveller to orient themselves relative to obstacles in a room and successfully avoid them. Echolocation has recently been rejected due to environmental influences that make it more difficult in noisy environments and social restrictions imposed by orientation and mobility instructors. Localisation could be attained through downconverted ultrasound echoes in the auditory domain, thus echolocation by ultrasound. This paper examines the interfaces that are currently used to display information to visually impaired individuals.

Testing a Novel Auditory Interface Display to Enable Visually Impaired Travelers to Use Sonar Mobility Devices Effectively

This paper discusses the pilot testing of an auditory interface designed to increase navigational ability of visually impaired individuals. Sonar devices have been developed to increase preview distances, but these have gained limited acceptance as they lack an easily interpreted interface. This paper presents usability testing of an auditory prototype interface developed using the work domain analysis of ecological interface design (EID). An interface design that provides the user with sufficient preview to avoid obstacles may offer more environmental information than the single tones of the current designs.

Underwater glider propulsion using chemical hydrides

A novel buoyancy engine for the propulsion of underwater gliders is presented. The research explores the direct volume expansion of hydrogen gas from the reaction of lithium hydride with seawater. As a result the seawater is expelled from the reaction chamber creating buoyancy and consequently also propulsion. The hydrogen produced can then be used to create electric energy in a fuel cell for use by the vehicle control system and on-board scientific payload.

A LUMPED PARAMETER MODEL OF TURBOPROP AIRCRAFT OPERATING ON GRAVEL RUNWAYS

The purpose of an aircraft Takeoff Performance Monitoring System (TOPMS) is to provide to the pilot information pertaining to the level of safety with which a takeoff is proceeding. The authors have developed a theoretical dynamic model to investigate the feasibility of using an observer system during the roll and takeoff phases of aircraft operation to provide to the pilot the information that is needed to manoeuver safely. This model was validated using a prototype device installed in a 19-passenger commercial turboprop aircraft. Unlike previous work in this field, this investigation focussed on various factors that are unique to the far-northern environment. Further, the Global Positioning System(GPS) was proposed as the sole source of kinematic information. This provided the possibility that a TOPMS could be devised that would require no additional ground-based installation. The results of a practical investigation 1 that was conducted to validate the theoretical model and signal processing technique appears in AIAA 2001-4170. The investigation showed that it was possible to predict the displacement of an aircraft to within 15 [m], the length of the test aircraft, in sufficient time to aid the pilot in decision-making.

Exploring direct downconversion of ultrasound for human echolocation

Human-computer interfaces for mobility devices to aid visually impaired individuals are deficient in the ease of use of systems. This paper examines the techniques used by blind individuals to spatialize naturally in their environments and seeks to explore the possibility of providing the same information in a manner that may be otherwise more socially acceptable.

Where did that sound come from? Comparing the ability to localise using audification and audition.

Purpose: A prototype device was developed to allow individuals to hear ultrasound reflections off environmental obstacles. Previous studies have shown that this device allows for better distance judgement than audition and allows for effective passage through the centreline of apertures. The purpose of this research was to evaluate audification as a method to localise direct sound sources as compared to audition. Method: In an anechoic environment, participants localised point-sound sources for three conditions: auditory, audified ultrasound with receivers facing laterally, and audified ultrasound with receivers facing forward. Results: Azimuth localisation was similar within a range of −35° to 35° in front of the participant among all conditions. At the periphery, −70° and 70°, audified ultrasound was more accurate than audition for novice participants. No difference was evident in user elevation accuracy for these signals among the different conditions. Conclusion: Audification of ultrasound can be effective for localising point-source sounds in the azimuth direction, but more evidence is required to evaluate accuracy in the vertical direction. Implications for Rehabilitation Secondary mobility devices can be used by individuals with visual impairment to avoid obstacles above waist height. Audification allows for skill-based response enabling intuitive obstacle avoidance and localization of point sound sources. Localization of peripheral sounds was shown in this study to be better with audified ultrasound than audition.

Experimental Testing of a Parametric-Model-Based Takeoff Performance Monitoring Strategy

The purpose of an aircraft takeoff performancemonitoring system is to provide to the pilot information pertaining to the level of safety with which a takeoff is proceeding. The concept of a takeoff performance monitoring system is not new. Instruments have been developed and flight-tested. However, the inclusion of a takeoff performance monitoring system as a standard instrument has yet to be embraced by manufacturers and operators. A simple theoretical dynamicmodel was developed to investigate the feasibility of using an observer systemduring the roll and takeoff phases of aircraft operation to provide to the pilot the information that is needed to maneuver safely. The viability of this simple model was validated using a prototype device installed in a 19-passenger commercial turboprop aircraft. Unlike previous work in this field, the Global Positioning Systemwas proposed as the sole source of kinematic information. This provided the possibility that a takeoff performance monitoring system could be devised that would require no additional ground-based installation. A Global Positioning System receiver and data acquisition systemwere installed in an aircraft operated by an airline servicing far-northernCanadian airports. The experimental investigation that was conducted to validate the theoretical model and signal processing technique showed that it was possible to predict the displacement of an aircraft to within 15 m, the length of the test aircraft, in sufficient time to aid the pilot in decision-making.

How far is that wall? Judging distance with audification

This research identified differences in the ability to determine distance using audible echolocation relative to audified ultrasound echoes with receivers mounted laterally and forward. In an anechoic environment, participants walked toward a stationary “wall” and provided an indication of perceived distance from the wall. Once the judgement was made, the participant walked to the location of the wall to provide an opportunity to recalibrate for future trials. At closer distances, no differences were observed among conditions, but at farther distances the results from the audified ultrasound were more accurate. The orientation of the receivers in the outward direction provided for better results overall in the judgement of distance to environmental obstacles.