52 resultados para chaotic and diffusive motion

em Deakin Research Online - Australia


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The aim of this paper is to design and develop an optimal motion cueing algorithm (MCA) based on the genetic algorithm (GA) that can generate high-fidelity motions within the motion simulator's physical limitations. Both, angular velocity and linear acceleration are adopted as the inputs to the MCA for producing the higher order optimal washout filter. The linear quadratic regulator (LQR) method is used to constrain the human perception error between the real and simulated driving tasks. To develop the optimal MCA, the latest mathematical models of the vestibular system and simulator motion are taken into account. A reference frame with the center of rotation at the driver's head to eliminate false motion cues caused by rotation of the simulator to the translational motion of the driver's head as well as to reduce the workspace displacement is employed. To improve the developed LQR-based optimal MCA, a new strategy based on optimal control theory and the GA is devised. The objective is to reproduce a signal that can follow closely the reference signal and avoid false motion cues by adjusting the parameters from the obtained LQR-based optimal washout filter. This is achieved by taking a series of factors into account, which include the vestibular sensation error between the real and simulated cases, the main dynamic limitations, the human threshold limiter in tilt coordination, the cross correlation coefficient, and the human sensation error fluctuation. It is worth pointing out that other related investigations in the literature normally do not consider the effects of these factors. The proposed optimized MCA based on the GA is implemented using the MATLAB/Simulink software. The results show the effectiveness of the proposed GA-based method in enhancing human sensation, maximizing the reference shape tracking, and reducing the workspace usage.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

To engage in the practice of photojournalism is to occupy a position of privilege, because the practice involves entering, albeit for a short while, the lives of others. But with this privilege comes the burden of representation. In this sense I believe that photojournalism is currently in crisis. This crisis concerns the decontextualization of the image in media outlets and the relegation of the photojournalist to the role of merely a hunter/gatherer rather than a storyteller. In other words, photojournalists have become alienated from the process of re-presentation of their own stories. To some extent it has always been thus.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Objective
This study examines the influence of posture on the range of axial rotation of the thorax and the range and direction of the coupled lateral flexion.

Methods

The ranges of mid thoracic axial rotation and coupled lateral flexion were measured in 52 asymptomatic subjects (aged 18-43 years) using an optical motion analysis system. To examine the influence of posture on primary and coupled motion, we initiated axial rotation from a neutral sitting posture and from end-range thoracic flexion and extension.

Results
There was a significant decrease in the range of thoracic rotation in flexion compared with the neutral and extended postures (P < .001). The mean range of coupled lateral flexion was 8.9% of the axial rotation range in the neutral posture and increased to 14.3% and 23.2% in the extended and flexed postures, respectively. Patterns of coupled motion varied between subjects, but an ipsilateral pattern was more common in the flexed posture, whereas a contralateral pattern was more common in the neutral and extended postures.

Conclusions

The ranges and patterns of coupled motion of the thorax appear to be strongly influenced by the posture from which the movement is initiated. This has important implications in relation to the interpretation of clinical tests of thoracic motion and in consideration of mechanisms of development of thoracic pain disorders.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Motion is a fundamental activity for the healthy functioning human organism. Its importance, however, is increasingly de-valued in Western cultures as they speed toward adopting technologies and virtual experiences as adjuncts to, and even replacements for7 traditional educational structures and processes that involve physical activity. Organised and reflective experience of human motion is becoming increasingly marginalised in teaching methodologies and learning programs in educational institutions at all levels around the globe. This inquiry sets out to gain a greater understanding of why people and human motion become disconnected, particularly during periods of formal education. A central question and two sub-questions form the basis of the inquiry. The central question asks why human motion is not valued and more utilised in education. In particular, why do learning areas that directly represent involvement with human motion, such as physical education, continually struggle in education programs. It directs the investigation to focus on the causes rather than the symptoms of the disuse and devaluation of human motion in Australian education. The two sub-questions split the praxis of the study. The first seeks to understand how the causes of devaluation work in the educational context lo affect the lack of acknowledgement; and the second considers ways to counter the disuse of human movement in education programs. To address these questions, the research focuses on rebutting the notion of a mind-body dualism. Rather, it seeks to better understand how humans learn and function as monists - integrated beings, acquiring self-knowledge in their 'world of being' in which bodily and emotional experiences, and reasoning are inextricably intertwined. I have approached this qualitative research as an ethnographic sociologist examining the issues from a critical high modernist perspective in order to demonstrate the pervading influence in Australian education of strong beliefs and values from the era of Enlightenment. Narrative analysis of 'memoir' in the form of self-defining memories was selected to gain a sensibility of the connectedness between human emotion, motion and reasoning in the lived experiences of students in three primary and three secondary schools across Years 2-12. An opportunity for human movement to be more valued and utilised in emerging educational frameworks that have life knowledge, dispositions and capabilities at their core is identified. The inquiry proposes a conceptualisation of human motion in education for new times characterised by the need for people to develop personal resources and strong positive identities in order to cope with a world of rapid change and uncertainty.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper presents experimental and computational results obtained on the Ford Barra 190 4.0 litres I6 gasoline engine and on the Ford Falcon car equipped with this engine. Measurements of steady engine performance, fuel consumption and exhaust emissions were first collected using an automated test facility for a wide range of cam and spark timings vs. throttle position and engine speed. Simulations were performed for a significant number of measured operating points at full and part load by using a coupled Gamma Technologies GT-POWER/GT-COOL engine model for gas exchange, combustion and heat transfer. The fluid model was made up of intake and exhaust systems, oil circuit, coolant circuit and radiator cooling air circuit. The thermal model was made up of finite element components for cylinder head, cylinder, piston, valves and ports and wall thermal masses for pipes. The model was validated versus measured steady state air and fuel flow rates, cylinder pressure parameters, indicated and brake mean effective pressures, and temperature of metal, oil and coolant in selected locations. Computational results agree well with experiments, demonstrating the ability of the approach to produce fairly accurate steady state maps of BMEP and BSFC, as well as to optimize engine operation changing geometry, throttle position, cam and spark timing. Measurements of the transient performance and fuel consumption of the full vehicle were then collected over the NEDC cycle. Simulations were performed by using a coupled Gamma Technologies GT-POWER/GT-COOL/GT-DRIVE model for instantaneous engine gas exchange, combustion and heat transfer and vehicle motion. The full vehicle model is made up of transmission, driveshaft, axles, and car components and the previous engine model. The model was validated with measured fuel flow rates through the engine, engine throttle position, and engine speed and oil and coolant temperatures in selected locations. Instantaneous engine states following a time dependent demand for torque and speed differ from those obtained by interpolating steady state maps of BSFC vs. BMEP and speed. Computational results agree well with experiments, demonstrating the utility of the approach in providing a more accurate prediction of the fuel consumption over test cycles.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In the present study we expand our analysis of using two contrasting organic solvent additives (toluene and THF) in an ionic liquid (IL)/Li NTf 2 electrolyte. Multinuclear Pulsed-Field Gradient (PFG) NMR, spin-lattice (T1) relaxation times and conductivity measurements over a wide temperature range are discussed in terms of transport properties and structuring of the liquid. The conductivity of both additive samples is enhanced the most at low temperatures, with THF slightly more effective than toluene. Both the anion and lithium self-diffusivity are enhanced in the same order by the additives (THF > toluene) while that of the pyrrolidinium cation is marginally enhanced. 1H spin-lattice relaxation times indicate a reasonable degree of structuring and anisotropic motion within all of the samples and both 19F and 7Li highlight the effectiveness of THF at influencing the lithium coordination within these systems.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In recent years, a narrative has emerged in the Australian popular media about the box office 'unpopularity' of Australian feature films and the 'failure' of the domestic screen industry. This article explores the recent history of Australian screen policy with particular reference to the '10BA' tax incentive of the 1980s; the Film Finance Corporation of Australia (FFC), a government screen agency established in 1988 to bring investment bank-style portfolio management to Australia's screen industry; and local production incentive policies pursed by Australian state governments in a chase for Hollywood's runaway production.

We argue the 10BA incentive catalysed an unsustainable bubble in Australian production, while its policy successor, the FFC, fundamentally failed in its stated mission of 'commercial' screen financing (over its 20-year lifespan, the FFC invested 1.345 billion Australian dollars for 274.2 million Australian dollars recouped - a cumulative return of negative 80 percent). For their part, private investors in Australian films discovered that the screen production process involved high levels of risk.

Foreign-financed production also proved highly volatile, due to the vagaries of trade exposure, currency fluctuations and tax arbitrage. The result of these macro and micro-economic factors often structural and cross-border in nature was that Australia's screen industry failed to develop the local investment infrastructure required to finance a sustainable, non-subsidised local sector.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Achieving adequate visualisation of designs within CAD packages remains a challenge for designers with current methods of 3D CAD visualisation requiring either a high level of technical ability, or expensive hardware and software. The recent re-emergence of consumer VR has lowered the barrier for everyday developers wanting to visualise their designs in true 3D. This paper presents the CAD Interaction Lab (CIL) which employs the Oculus Rift Head Mounted Display (HMD) and Leap Motion Controller (LMC) to provide a low cost method enabling users to use their hands to dissect a mechanic model to manipulate and inspect individual components in realistic 3D. Qualitative observations of user interactions with the CIL show that users were able to intuitively manipulate the CAD model using natural hand movements with only minimal instruction.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A platform to move gait analysis, which is normally restricted to a clinical environment in a well-equipped gait laboratory, into an ambulatory system, potentially in non-clinical settings is introduced. This novel system can provide functional measurements to guide therapeutic interventions for people requiring rehabilitation with limited access to such gait laboratories. BioKin system consists of three layers: a low-cost wearable wireless motion capture sensor, data collection and storage engine, and the motion analysis and visualisation platform. Moreover, a novel limb orientation estimation algorithm is implemented in the motion analysis platform. The performance of the orientation estimation algorithm is validated against the orientation results from a commercial optical motion analysis system and an instrumented treadmill. The study results demonstrate a root-mean-square error less than 4° and a correlation coefficient more than 0.95 when compared with the industry standard system. These results indicate that the proposed motion analysis platform is a potential addition to existing gait laboratories in order to facilitate gait analysis in remote locations.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Our aim is to estimate the perspective-effected geometric distortion of a scene from a video feed. In contrast to most related previous work, in this task we are constrained to use low-level spatiotemporally local motion features only. This particular challenge arises in many semiautomatic surveillance systems that alert a human operator to potential abnormalities in the scene. Low-level spatiotemporally local motion features are sparse (and thus require comparatively little storage space) and sufficiently powerful in the context of video abnormality detection to reduce the need for human intervention by more than 100-fold. This paper introduces three significant contributions. First, we describe a dense algorithm for perspective estimation, which uses motion features to estimate the perspective distortion at each image locus and then polls all such local estimates to arrive at the globally best estimate. Second, we also present an alternative coarse algorithm that subdivides the image frame into blocks and uses motion features to derive block-specific motion characteristics and constrain the relationships between these characteristics, with the perspective estimate emerging as a result of a global optimization scheme. Third, we report the results of an evaluation using nine large sets acquired using existing closed-circuit television cameras, not installed specifically for the purposes of this paper. Our findings demonstrate that both proposed methods are successful, their accuracy matching that of human labeling using complete visual data (by the constraints of the setup unavailable to our algorithms).

Relevância:

100.00% 100.00%

Publicador:

Resumo:

An effective scheme for soccer summarization is significant to improve the usage of this massively growing video data. The paper presents an extension to our recent work which proposed a framework to integrate highlights into play-breaks to construct more complete soccer summaries. The current focus is to demonstrate the benefits of detecting some specific audio-visual features during play-break sequences in order to classify highlights contained within them. The main purpose is to generate summaries which are self-consumable individually. To support this framework, the algorithms for shot classification and detection of near-goal and slow-motion replay scenes is described. The results of our experiment using 5 soccer videos (20 minutes each) show the performance and reliability of our framework.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The thesis takes up the question of the representation of the migrant on the Australian screen in terms of a specific set of concerns around the notions of stereotype and self-reflexivity. The stereotype is read as a self-referential image: hence, as a question of film spectatorship and identity; in short as an unconscious reflex or self image. The text of the thesis is in two parts: part one, comprises the production of the film ‘Italians at home’. It is the major component of research and text which, for this purpose, has been copied and submitted hereto on VHS video cassette. Part two, includes an analysis and discussion of the television documentary ‘The migrant experience’, and an exegesis, of the production, narrative and reception of the film ‘Italians at home’. The migrant experience is read and discussed as an exemplary text of dominant, stereotyped discourse of cultural difference; while ‘Italians at home’ is proposed as a parallel text and a self-reflexive reading and criticism of such a text. Both the television documentary and the film, deal with the representation and problematic of homogenised representations of ethnicity. In the case of ‘The migrant experience’, it is argued, that the figure of the migrant as other and self-image, functions as an object of Australian culture and discourse of national identity within a logic of representation of binary structures; while the film ‘Italians at home’, the question of self-referentiality is seen in terms of the viewing subject and a problematic of film representation; thus, the film attempts to make such signifying structures, visual codes and agreed assumptions of otherness visible, while, at the same time, attempting to displace them or pose them as a problem of representation or reading for the viewer.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The aim of the research was to generate a cyclonic model for understanding the influences and processes of continuously improving management education in an environment rich in online learning technologies. The research questions were:
1. What is the nature of the cyclonic interactions observed in the transactions of a team of online management educators?
2. How might an understanding of cyclonic interactions
a. help refine action research, and
b. generate rich insight for online management education?
The methodology was an action research project. The research team worked in an online Master of Business Administration (MBA) to continuously develop teaching practice in one unit of the MBA. The methodology matched the objectives of the project, and the appropriate rigour associated with qualitative, interpretive research. The results showed that theories of systems and relational dynamics, adapted to hermeneutics and aligned with other learning theories, can be framed by the metaphor of a cyclone to conduct research into teaching practice and build upon the theory base in the field of online education.
Online management education is subject to reinterpretations. The cyclonic framework explains some of the changes. The project showed that a chaotic but organised cyclonic program development process in one particular MBA course was informative for and informed by the chaotic and cyclonic globalized business world. For the education of managers the cyclonic view was relevant. The approach was metaphorical and, therefore, opened new ways of seeing and speaking. Findings pertained to the nature of the cyclonic interactions, how an understanding of cyclonic interactions helped to refine action research, and how an understanding of cyclonic interactions helped generate rich insight for online management education.
It was found that it was the asymmetrical impetus of imperfection that created the examples of cyclonic learning spirals formed as double feedback loops for improved understanding. Online education in the action research required cyclical enhancement of connectedness by teachers, stronger emphasis on relational considerations in learning, and heightened expectations of collaboration by educators. It became possible to correlate earlier conceptions of action research with cyclonic categories and analyse the parallels with events in this action research project. Models were developed and presented to explain 3 cyclonic connections with hermeneutics, collaborative teaching, online resource
development, and the environment of online management.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Examines Terry Gilliam's cinema via his interest in systems: mechanical, philosophical, aesthetic, mythological and scientific. Argues for Gilliam as in interpreter of the late twentieth century experience, his films interweaving contemporary theory with archaic lore in dramatisation of the ongoing quest to apprehend the world's processes.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Kathryn Bigelow has undoubtedly been one of Hollywood's most significant female players, well known in popular terms for films such as Point Breakand Blue Steel, yet relatively unexplored in academia. Soundbites about women and guns and speculation about the role of ex-husband James Cameron ( Aliens, Titanic) in her career have often helped obscure rather than elucidate an understanding of her work. This collection explores how Bigelow can be seen to provide a point of intersection to a whole range of issues at the forefront of contemporary film studies and of the transformation of Hollywood into a post-classical cinema machine, with a particular emphasis on her most ambitious and controversial picture, Strange Days. Her place within new Hollywood is as a filmmaker that blurs genre conventions, reinscribes gender identites, and produces a breathless cinema of attractions.