29 resultados para Lift (Aerodynamics)


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In this paper we present the findings of a group problem-solving task involving eight randomly selected students. The focus of this study was to identify and explore students' application of generic skills, cross-disciplinary knowledge and skills, innovative thinking and engineering disciplinary knowledge. While this was the main aim of this study, we also used the findings of this study to triangulate the findings of a broader study which aims to identify and explore students' perceptions of problem based learning (PBL) in first year electrical engineering. The broader qualitative study of learners in a problem based engineering context will identify, explore and report on the factors that influence student learning behaviours and their attitudes as future engineers. Studying the learning cultures from the students' view point in a diverse student group should provide evidence to further theorize about the models of self-regulation in autonomous learners. For this group problem solving activity, we designed a problem (advanced lift controller system) and allowed students one hour to work on a solution for this problem. The eight students from a number of actual PBL groups were divided into two groups depending upon their availability. Both groups were given the same problem. The researcher played the role of a facilitator and collected the data simultaneously. Students were given access to books relevant to the problem, computer access and access to the Internet. They were also provided with links to sample websites such as the University's electronic library and other technology related websites on the World Wide Web. The activity was designed such that students were not required to arrive at a definite outcome. However, they were asked to brainstorm ideas, and as a group, to decide on ways that they would obtain and share information and to formulate and suggest possible innovative solutions to the problem. Data for this activity was collected by means of observation. The activity was audio and video recorded in order to help revisit the data at any stage. At the time this study was conducted, students had completed two PBL units in their first year of an electronic and electrical engineering undergraduate degree course. This study also provided insight into students' attitudes and their behaviours towards learning in a group setting, learning approaches and outcomes, different responses to the heterogeneity of the students in the group, and their responsibility and accountability in an autonomous learning setting such as PBL.

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Exercise or Swiss balls are increasingly being used with conventional resistance exercises. There is little evidence supporting the efficacy of this approach compared to traditional resistance training on a stable surface. Previous studies have shown that force output may be reduced with no change in muscle electromyography (EMG) activity while others have shown increased muscle EMG activity when performing resistance exercises on an unstable surface. This study compared 1RM strength, and upper body and trunk muscle EMG activity during the barbell chest press exercise on a stable (flat bench) and unstable surface (exercise ball). After familiarization, 13 subjects underwent testing for 1RM strength for the barbell chest press on both a stable bench and an exercise ball, each separated by at least 7 days. Surface EMG was recorded for 5 upper body muscles and one trunk muscle from which average root mean square of the muscle activity was calculated for the whole 1RM lift and the concentric and eccentric phases. Elbow angle during each lift was recorded to examine any range-of-motion differences between the two surfaces. The results show that there was no difference in 1RM strength or muscle EMG activity for the stable and unstable surfaces. In addition, there was no difference in elbow range-of-motion between the two surfaces. Taken together, these results indicate that there is no reduction in 1RM strength or any differences in muscle EMG activity for the barbell chest press exercise on an unstable exercise ball when compared to a stable flat surface. Moreover, these results do not support the notion that resistance exercises performed on an exercise ball are more efficacious than traditional stable exercises.

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Motorbike riders are 34-times more likely to die in a crash compared to car drivers per km travelled (1). Such safety risks together with special skill requirements for the driver and much lower comfort compared to normal cars are the main reasons why motorbikes represent only a fraction of all vehicle sales in developed countries. Deakin University is developing a revolutionary cross-over fun vehicle with ultra low fuel consumption and emissions. This new vehicle generation combines the best of two worlds: the fun to drive, low cost, and small size of a scooter together with the safety, comfort and easiness to operate of a car. The result is a vehicle that is more fuel efficient than most cars or even scooters.

Various tilting cross over vehicles have been presented over the last decade that were trying to automate the tilting control of narrow vehicles to make them safer. Examples of these concepts are the Carver, Clever and in some way also the MP3 scooter from Piaggio. The problem with fully enclosed concepts like the Carver or Clever is that they require very complex and therefore also expensive tilting control systems so that the vehicles are not price competitive compared to low cost micro cars or even normal small cars. The MP3 on the other hand comes with a tilting control system which is only semi automatic so that typical car advantages - comprehensive safety features like crush zones, roll over protection, air bags, safety belts or comfort features like full weather protection including heating and cooling – can not be provided.

Deakin’s approach is quite different to the above mentioned concepts. The requirements were derived based on two different investigations: The first step was a critical evaluation of social trends and the second step was an in-depth benchmarking study of existing concepts which identified the typical strengths and weaknesses of these concepts. In a critical next step a new concept was created that addresses most of the weaknesses of existing tilting three-wheelers in a holistic approach by setting clear priority rankings for the vehicle targets, based on current trends. The priorities were set in the following order: Safety, Affordability, Fun and Efficiency (SAFE).

The key feature that enables an enclosed tilting vehicle is a fully automatic tilting control system. With an automatic tilting control system the driver does not need to put the feet on the ground to balance the vehicle when he stops, so the vehicle can be built with a full enclosure. This allows the implementation of typical car like safety features (seat belts, roll over structure, crush zones, air bags). The SafeRide™ tilting control system is a passive system that involves the driver’s balancing sense in its feedback control system. The vehicle has typical scooter like steering characteristics, where the steering is initiated through countersteering. Another safety critical design feature is the crush zone between the two front wheels which is not possible with only one front wheel or with the powertrain positioned between the front wheels, as the powertrain can’t absorb a lot of energy due to its structural stiffness and density. The passive tilting control system is quite simple and therefore makes the vehicle very affordable, an important factor for successful commercialisation.

Another advantage of integrating the human balancing senses in the feedback control of the tilting system is that the system kicks in slightly after the human balancing reacts. In some instances that can generate the typical adrenalin thrill known from riding a bike. This fun factor is quite common with many trend sports like mountain biking, surfing, roller-skating, snowboarding, or skateboarding. Some of these sports have seen very rapid growth only a short time after they have been invented. Utilising the human balancing system during driving also makes the vehicle safer as the adrenalin is produced after reaching a semi-stable driving condition that is controlled by the vehicles tilting control system, but before the vehicle reaches an unstable driving condition that can not be controlled by the vehicle but only (eventually) by the driver – if he has got the required driving skill and if he is alert enough.

Efficiency superior to most cars and scooters is achieved by the aerodynamics of a fully enclosed body structure in combination with the small frontal area of a typical scooter and the droplet shape enabled by the relatively wide front with 2 wheels and the very narrow tail with only one rear wheel. The passive tilting system also contributes to the extreme efficiency as the system only draws some small electrical power for the electronic control unit. Another feature is a low cost exhaust energy recovery system which is discussed in another paper.

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In 2010, Defence Force Recruiting (DFR) Navy Marketing entered into a media sponsorship package with the Australian version of the reality TV show So You Think You Can Dance (SYTYCD): Footage of the day aired on national television on SYTYCD and weekly ‘dancer bootcamp’ sessions training the dancers in Navy values featured on a dedicated and branded Navy section of the official SYTYCD website. This article analyses the Navy’s SYTYCD ‘integration opportunities’ to consider the role of reality television in the redefinition of the defence forces as a training and vocational pathway for young people. Underpinning such considerations is the conceptualization of the work of reality television through the prism of public and popular pedagogies. Taking sexuality as a focal point, the article will reflect on efforts to lift recruitment through an emphasis on the incorporation of diversity. Reading the work of Jasbir Puar against the Australian ‘archive’ of integration opportunities, this article contributes to queer critiques of homonormative and homonationalist tendencies in contemporary politics.

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The occurrence of so-called sticking points in a lift is pervasive in weight training practice. Biomechanically complex exercises often exhibit multi modal variation of effective force exerted against the load as a function of the elevation and velocity of the load. This results in a variety of possible loci for the occurrence of sticking points and makes the problem of designing the optimal training strategy to overcome them challenging. In this article a case founded on theoretical grounds is made against a purely empirical method. It is argued that the nature of the problem considered and the wide range of variables involved limit the generality of conclusions which can be drawn from experimental studies alone. Instead an alternative is described, whereby a recently proposed mathematical model of neuromuscular adaptation is employed in a series of computer simulations. These are used to examine quantitatively the effects of differently targeted partial range of motion (ROM) training approaches. Counter-intuitively and in contrast to common training practices, the key novel insight inferred from the obtained results is that in some cases the most effective approach for improving performance in an exercise with a sticking point at a particular point in the ROM is to improve force production capability at a different and possibly remote position in the lift. In the context of the employed model, this result is explained by changes in the neuromuscular and biomechanical environment for force production.

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A simple and general patterning technique for inorganic nanoparticles (NPs, e.g., gold NPs) is demonstrated, consisting of the selective lift-off of metal precursor loaded block copolymer micelles. The procedure works as follows: first, a topographically micropatterned polystyrene (PS) stamp is placed in contact with a substrate covered with hexagonally arranged micelles. Then the assembly is heated above the glass transition temperature (Tg) of PS, and finally, the PS stamp is peeled off, removing from the substrate the micelles that were in contact with the protrusions of the stamp. As a result, patterns of micelles either exactly identical to the original or with much smaller features down to submicrometer were obtained. In a subsequent step, the organic material can be removed and the metal precursor reduced by plasma treatment, resulting in patterns of NPs. This technique, denoted as “μ-contact deprinting”, provides a fast and inexpensive way to obtain hierarchical patterns of NPs on a wide range of substrates. It is demonstrated that it can even be applied on curved surfaces because of the softness of the PS stamp above its T

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The ability of porous media to transmit fluids is commonly referred to as permeability. The concept of permeability is central for hydrocarbon recovery from petroleum reservoirs and for studies of groundwater flow in aquifers. Spatially resolved measurements of permeability are of great significance for fluid dynamics studies. A convenient concept of local Darcy’s law is suggested for parallel flow systems. The product of porosity and mean velocity images in the plane across the average flow direction is directly proportional to permeability. Single Point Ramped Imaging with T 1 Enhancement (SPRITE) permits reliable quantification of local fluid content and flow in porous media. It is particularly advantageous for reservoir rocks characterized by fast magnetic relaxation of a saturating fluid. Velocity encoding using the Cotts pulsed field gradient scheme improves the accuracy of measured flow parameters. The method is illustrated through measurements of 2D permeability maps in a capillary bundle, glass bead packs and composite sandstone samples.

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Performance with 3 16mm Projectors and one video projector at Liaison of Independent Filmmakers Toronto, using materials produced in the workshop and the residency. Included was a text spoken in Dutch and English from Abel Tasman's landing on Tasmania's shores during his voyage of expedition.

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Rote Movie (1994, 16mm, 12 min.)Understanding Science (1992, 16mm. 18 min.)Death Of Place (2013, digital, 14 min.)Empire (2014, digital, silent, 8 min.)Found Found Found (2014, digital, 18 min.)

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Regional Support Network presents:A Sampled OZ Hystery: Australian Alternative Film from the 60s to the PresentTuesday, October 21, 8pm ($5 or PWYC)Videofag (187 Augusta Avenue)(co-sponsored by Videofag and Liaison of Independent Filmmakers of Toronto (LIFT))Curated by Dirk De Bruyn (in person)PROGRAM:Fun Radio - Nigel BuesstLeading Ladies - Lynsey MartinContemplation of the Rose - Michael LeeZoomfilm - Dirk de BruynDiscs - Dirk de BruynDolls - Paul FletcherExcerpt - Chris KnowlesExacuate - Michael Buckley and Sue McCauleyMorena - Marie CravenShort Lives - Neil TaylorE.G. (Elephant Girl) - Virginia HilyardTraum A Dream - Dirk de BruynKeepinTime Abstract - Steven McIntyreTime Ball - Marcia JaneWAP - Dirk de Bruyn

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This study is the first to examine the immediate impact that succession events (e.g., removal and hiring) involving head coaches have on season ticket holder (STH) attitudes like satisfaction and renewal intentions. Grounded within a customer equity framework, large-scale survey data from cases of two professional sport teams is presented showing STH attitudes directly before and after major succession events. The data shows that appointing a new coach was met with increases in positive attitudes toward almost every aspect of the STH experience, where the case of removing a coach had no meaningful impact on attitudes. The findings of these cases reaffirm the view that coach succession is a multiple-phase process including distinct stages of removal and replacement. While it is the desire for improved on-field performance that often motivates coach succession, our findings suggest the impact of succession activities on fans is more wide ranging, with significant implications for marketers who manage fan relationships. In guiding the management of a team's fans, coach removal alone should not be relied upon to change attitudes or intentions toward a club. Appointing new leaders completes the cycle, increasing positive STH attitudes and, most importantly, giving an immediate lift to renewal likelihood.

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A teal (Anas crecca) and a thrush nightingale (Luscinia luscinia) were trained to fly in the Lund wind tunnel for periods of up to 3 and 16 h respectively. Both birds flew in steady flapping flight, with such regularity that their wingbeat frequencies could be determined by viewing them through a shutter stroboscope. When flying at a constant air speed, the teal's wingbeat frequency varied with the 0.364 power of the body mass and the thrush nightingale's varied with the 0.430 power. Both exponents differed from zero, but neither differed from the predicted value (0.5) at the 1 % level of significance. The teal continued to flap steadily as the tunnel tilt angle was varied from -1° (climb) to +6° (descent), while the wingbeat frequency declined progressively by about 11%. In both birds, the plot of wingbeat frequency against air speed in level flight was U-shaped, with small but statistically significant curvature. We identified the minima of these curves with the minimum power speed (Vmp) and found that the values predicted for Vmp, using previously published default values for the required variables, were only about two-thirds of the observed minimum-frequency speeds. The discrepancy could be resolved if the body drag coefficients (CDb) of both birds were near 0.08, rather than near 0.40 as previously assumed. The previously published high values for body drag coefficients were derived from wind-tunnel measurements on frozen bird bodies, from which the wings had been removed, and had long been regarded as anomalous, as values below 0.01 are given in the engineering literature for streamlined bodies. We suggest that birds of any size that have well-streamlined bodies can achieve minimum body drag coefficients of around 0.05 if the feet can be fully retracted under the flank feathers. In such birds, field observations of flight speeds may need to be reinterpreted in the light of higher estimates of Vmp. Estimates of the effective lift:drag ratio and range can also be revised upwards. Birds that have large feet or trailing legs may have higher body drag coefficients. The original estimates of around CDb=0.4 could be correct for species, such as pelicans and large herons, that also have prominent heads. We see no evidence for any progressive reduction of body drag coefficient in the Reynolds number range covered by our experiments, that is 21600-215 000 on the basis of body cross-sectional diameter.

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Musculoskeletal injuries are reported as burdening the military. An identified risk factor for injury is carrying heavy loads; however, soldiers are also required to wear their load as body armour. To investigate the effects of body armour on trunk and hip kinematics during military-specific manual handling tasks, 16 males completed 3 tasks while wearing each of 4 body armour conditions plus a control. Three-dimensional motion analysis captured and quantified all kinematic data. Average trunk flexion for the weightiest armour type was higher compared with control during the carry component of the ammunition box lift (p < 0.001) and sandbag lift tasks (p < 0.001). Trunk rotation ROM was lower for all armour types compared with control during the ammunition box place component (p < 0.001). The altered kinematics with body armour occurred independent of armour design. In order to optimise armour design, manufacturers need to work with end-users to explore how armour configurations interact with range of personal and situational factors in operationally relevant environments. Practitioner Summary: Musculoskeletal injuries are reported as burdening the military and may relate to body armour wear. Body armour increased trunk flexion and reduced trunk rotation during military-specific lifting and carrying tasks. The altered kinematics may contribute to injury risk, but more research is required.

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Dynamically changing background (dynamic background) still presents a great challenge to many motion-based video surveillance systems. In the context of event detection, it is a major source of false alarms. There is a strong need from the security industry either to detect and suppress these false alarms, or dampen the effects of background changes, so as to increase the sensitivity to meaningful events of interest. In this paper, we restrict our focus to one of the most common causes of dynamic background changes: 1) that of swaying tree branches and 2) their shadows under windy conditions. Considering the ultimate goal in a video analytics pipeline, we formulate a new dynamic background detection problem as a signal processing alternative to the previously described but unreliable computer vision-based approaches. Within this new framework, we directly reduce the number of false alarms by testing if the detected events are due to characteristic background motions. In addition, we introduce a new data set suitable for the evaluation of dynamic background detection. It consists of real-world events detected by a commercial surveillance system from two static surveillance cameras. The research question we address is whether dynamic background can be detected reliably and efficiently using simple motion features and in the presence of similar but meaningful events, such as loitering. Inspired by the tree aerodynamics theory, we propose a novel method named local variation persistence (LVP), that captures the key characteristics of swaying motions. The method is posed as a convex optimization problem, whose variable is the local variation. We derive a computationally efficient algorithm for solving the optimization problem, the solution of which is then used to form a powerful detection statistic. On our newly collected data set, we demonstrate that the proposed LVP achieves excellent detection results and outperforms the best alternative adapted from existing art in the dynamic background literature.