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Links between Subjective Assessments and Objective Metrics for SteeringSu, He, Zhicheng, Xuxin January 2012 (has links)
The characteristics of vehicle steering perception are decisive factors concerning vehicle safety and overall pleasure behind the wheel. It is a challenge for vehicle manufacturers to achieve these features and qualities, because usually vehicle tuning almost only relies on subjective evaluation of test drivers, which is costly and time consuming. In order to optimize suspension design and develop a tool that can be used to evaluate steering with objective metrics instead of subjective assessment, links between them must be confirmed. In this master thesis, both objective and subjective testing data of over 20 vehicles across four different segments are introduced in linear and nonlinear analysis. Linear regression analysis is applied to investigate simply positive or negative correlation between a pair of subjective-objective parameters. However, even if certain linear correlations are obtained, it is still hard to define the optimal value for objective metrics. Considering that the general shape of a correlation function can reveal which objective range give higher subjective rating, it is possible to define these preferred ranges with Neural Network (NN). The best data available is adopted from three drivers who tested 15 sedans, and some interesting results are found. The initial results demonstrate that NN is a powerful tool to uncover and graphically illustrate the links between objective metrics and subjective assessments, i.e., the specific range leading to better steering feel. Given a larger sample size, more reliable and optimal links can be defined by following the same method. These confirmed links would enable vehicle dynamics engineers to more effectively develop new vehicles with nearly perfect steering feel.
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Design of Multi-Platform Control Software for Telemetry SystemsMahini, Farid 10 1900 (has links)
International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / This paper discusses the requirements and design of a multi-platform system software for control, status, calibration and testing of a telemetry system.
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Criteria for acceptable stick force gradients of a light aeroplaneBromfield, Michael January 2012 (has links)
During the period 1980 to 2008 there were 359 fatal accidents involving UK registered light aeroplanes of which 36% occurred in visual meteorological conditions. In all, 216 lives were lost with accidents being attributed to the pilot 'failing to maintain proper control resulting in a stall or spin'. Dissimilar fatal stallrelated accident rates are evident for aeroplane makes & models of similar design. During the course of this programme of research, flight testing of two similar aeroplane models using a case study method showed marked differences in the variation of stick force with airspeed or stick force gradient in all flight conditions. This suggested that 'control feel' was a contributory factor towards the pilot’s failure to maintain proper control. Current certification standards for light aeroplanes rely upon the subjective assessment of stick force gradients by test pilots, requiring that substantial changes in airspeed are accompanied by clearly perceptible changes in stick force with no specified minimum gradient. This programme of research has been carried out to determine acceptable criteria for stick force gradients of a light aeroplane in all flight conditions. Criteria has been determined from flight tests of aeroplanes with different in-service safety records and subjective pilot workload assessment using simulated flying tasks with different stick force gradients performed by twenty GA pilots. Simulation tests indicated that pilot mental demand increased significantly (p > 0.05) when stick force gradient was reduced to ‘zero’, representing an aeroplane with neutral longitudinal static stability. A predictive model has been developed to estimate stick force gradients for a light aeroplane in any flight condition under quasi-static, longitudinal, non-manoeuvring flight and 1-g loading conditions. The model builds upon previous published work limited to cruising flight, and enables the estimation of stick forces and gradients due to high lift devices in the climb and landing condition by consideration of the combined effects of wing loading, CG, elevator gearing, flaps and elevator trim setting. Implemented using MATLAB, the model has been validated by comparing with flight test results for the case study aeroplanes and showed mean differences of ±0.025 daN/kt. The predictive model should be used in preliminary aeroplane design to assess tendencies towards neutral stability in high workload, safety critical flight conditions such as the take-off and landing. In addition, the model should be used to analyse existing aeroplanes with comparatively low or neutral stick force gradients in safety critical flight phases and to predict the effects of changing CG and/or flap limits to increase stick force gradient and improve control feel. The combined results of these studies suggest that a minimum acceptable stick force gradient for a non-aerobatic light aeroplane in all flight conditions should be nonzero and between 0.10~0.13 daN/kt. A stable and predictable stick force variation with airspeed will ensure that any substantial deviation from trimmed airspeed is accompanied by a stick force change clearly perceptible to the pilot and also provide additional warning of the proximity to the stall. The use of specific criteria to complement qualitative test pilot opinion, will assist in confirming compliance and provide consistency with current standards for sailplanes/powered sailplanes and large commercial aeroplanes, both of which already have defined minimum acceptable gradients.
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Towards efficient vehicle dynamics development : From subjective assessments to objective metrics, from physical to virtual testingGil Gómez, Gaspar January 2017 (has links)
Vehicle dynamics development is strongly based on subjective assessments (SA) of vehicle prototypes, which is expensive and time consuming. Consequently, in the age of computer- aided engineering (CAE), there is a drive towards reducing this dependency on physical test- ing. However, computers are known for their remarkable processing capacity, not for their feelings. Therefore, before SA can be computed, it is required to properly understand the cor- relation between SA and objective metrics (OM), which can be calculated by simulations, and to understand how this knowledge can enable a more efficient and effective development process. The approach to this research was firstly to identify key OM and SA in vehicle dynamics, based on the multicollinearity of OM and of SA, and on interviews with expert drivers. Sec- ondly, linear regressions and artificial neural network (ANN) were used to identify the ranges of preferred OM that lead to good SA-ratings. This result is the base for objective require- ments, a must in effective vehicle dynamics development and verification. The main result of this doctoral thesis is the development of a method capable of predicting SA from combinations of key OM. Firstly, this method generates a classification map of ve- hicles solely based on their OM, which allows for a qualitative prediction of the steering feel of a new vehicle based on its position, and that of its neighbours, in the map. This prediction is enhanced with descriptive word-clouds, which summarizes in a few words the comments of expert test drivers to each vehicle in the map. Then, a second superimposed ANN displays the evolution of SA-ratings in the map, and therefore, allows one to forecast the SA-rating for the new vehicle. Moreover, this method has been used to analyse the effect of the tolerances of OM requirements, as well as to verify the previously identified preferred range of OM. This thesis focused on OM-SA correlations in summer conditions, but it also aimed to in- crease the effectiveness of vehicle dynamics development in general. For winter conditions, where objective testing is not yet mature, this research initiates the definition and identifica- tion of robust objective manoeuvres and OM. Experimental data were used together with CAE optimisations and ANOVA-analysis to optimise the manoeuvres, which were verified in a second experiment. To improve the quality and efficiency of SA, Volvo’s Moving Base Driving Simulator (MBDS) was validated for vehicle dynamics SA-ratings. Furthermore, a tablet-app to aid vehicle dynamics SA was developed and validated. Combined this research encompasses a comprehensive method for a more effective and ob- jective development process for vehicle dynamics. This has been done by increasing the un- derstanding of OM, SA and their relations, which enables more effective SA (key SA, MBDS, SA-app), facilitates objective requirements and therefore CAE development, identi- fies key OM and their preferred ranges, and which allow to predict SA solely based on OM. / <p>QC 20170223</p> / iCOMSA
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Effect of Reduced-Fee Dental Hygiene Treatment and Oral Health Perceptions Among Socioeconomically Deprived PersonsAsbury, Janeime Necole 01 January 2016 (has links)
Access to oral health care remains problematic for millions of Americans. Factors such as socioeconomic status, age, race, and lack of dental insurance benefits inhibit the ability of many to obtain preventative oral health care. The aim of this study was to explore the effect of preventive oral health treatment and education at reduced-fee dental hygiene facilities on the oral health behaviors and perceptions of socioeconomically deprived persons within the state of Georgia. This study was based on the health belief model constructs. A convenience sample of 102 participants was recruited from the individuals who visited two dental hygiene colleges to seek treatment for the first time. The independent variable was the receipt of reduced-fee dental hygiene treatment/education. The dependent variables were the oral health perceptions and behaviors of socioeconomically deprived persons, as well as the perceptions and behaviors of patients provided with a referral for follow-up treatment with a dentist. Mediating variables were sex, age, race, and socioeconomic status. Wilcoxon Signed Rank test and logistic regression were applied to detect potential differences in the dependent variables before and after treatment. The most significant changes were found in categories dealing with self-efficacy measures that patients could take to improve their own oral health. Also, the oral health behaviors and perceptions of younger, African-American of low educational and financial background were significantly more improved after treatment. The social change implication of this research may be that oral health practitioners can use these results to create preventative interventions more tailored for socioeconomically deprived persons who face complicated oral health issues.
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Assessment of crosswind performance of busesJuhlin, Magnus January 2009 (has links)
When driving a vehicle on the road, the driver has to compensate continuously for small directional deviations from the desired course due to disturbances such as crosswinds, road irregularities and unintended driver inputs. These types of deviations have a tiring effect on the driver and should therefore be minimised. When the magnitude of these disturbances increases, especially with crosswind, the directional deviation might become so large that the driver will have difficulties in compensating for it, and will thereby affect the traffic safety. The objective of this research work is to increase the understanding of the crosswind sensitivity of buses and to find solutions to the problem of improving the safety of buses with respect to crosswind performance. The work presented in this thesis contributes to increased knowledge about the directional stability of buses under the influence of crosswind gusts through parameter studies using detailed vehicle simulation models, through full-scale experiments and through studies of the effect of steering feel on the subjective and objective evaluation of crosswind performance. A natural crosswind gust model has been derived from wind tunnel measurements and implemented in a multi-body dynamics simulation tool. The aerodynamic loads of the crosswind gust model have been applied on a detailed vehicle model and the behaviour of the vehicle model has been studied for various vehicle configurations in both open- and closed-loop manoeuvres. The vehicle model, with parameters corresponding to real vehicle data, has been validated and the agreement with measurements is good. A method for estimating the aerodynamic loads on a bus due to crosswind on a road section is also presented. Aerodynamic loads under real conditions were estimated using this method and these data were thereafter used in a study where the effect of steering feel on the subjective and objective evaluation of crosswind performance was investigated using a moving-base driving simulator, with the aim of finding a relationship between steering feel and crosswind sensitivity. The thesis covers the influence of changing chassis-related parameters and aerodynamics-related parameters on the crosswind sensitivity, as well as the influence of the setting of the steering system on the crosswind performance of the driver-vehicle system. The results identify areas of high potential for improving the crosswind sensitivity of buses, such as the centre of gravity location and the yaw moment overshoot at gust entry. Furthermore, the study shows the importance of having a vehicle that facilitates prompt driver corrections for reducing the lateral deviation under crosswind excitation; i.e. it is shown that a steering system with the possibility of changing the yaw rate gradient referencing the steering-wheel input when the vehicle is subjected to a sudden crosswind has a good potential for improving the crosswind performance of the driver-vehicle system. / QC 20100722
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Wo ist das Gefühl?Freitag, Georg, Wacker , Markus 27 May 2014 (has links) (PDF)
"Das Programm sieht ja nicht nur gut aus, es macht auch genau das was ich will!" - solche oder ähnliche Aussagen liest man oft, wenn Software-Programme von Anwendern beurteilt werden. Was Nutzer damit beschreiben ist weitestgehend als Look & Feel einer Anwendung bekannt. Der Begriff Look bezieht sich dabei auf die visuellen Bestandteile der Anwendung, wie die genutzten Medienelemente und deren Layout. Das Themenfeld Feel umfasst das interaktive Verhalten einer Anwendung, die auf Eingaben des Nutzers reagiert (Feedback) oder bereits vorher Hinweise auf die eigene Verwendbarkeit gibt (Feed-Forward). Allgemein gilt, je interaktiver eine Anwendung, desto wichtiger ist das "Gefühl" im Look & Feel. Als Beispiel dienen die sogenannten natürlichen Benutzerschnittstellen (NUI), wie die sich in den letzten Jahren enorm verbreitende Form des Multi-Touches. Bei dieser interagiert der Nutzer direkt mit der Anwendung ohne separate Eingabegeräte als Vermittler seiner Aktionen. Eine weitere Charakteristik dieser Benutzerschnittstellen ist deren intuitive Verwendbarkeit. Dies bedeutet, dass sich während der Interaktion mit den Programmen deren Strukturen und Funktionen von selbst erschließen. Um dies zu gewährleisten ist die sorgsame Gestaltung des Feels von Beginn der Entwicklung an bedeutsam. Umso überraschender ist das Ergebnis unseres Vergleichs aktueller Prototyping-Werkzeuge für Benutzeroberflächen, die den Aspekt Feel oftmals nicht oder nur unzureichend berücksichtigen und stattdessen das Aussehen (Look) einer Anwendung fokussieren. In unserer kürzlich erschienenen Arbeit "Look without Feel - A Basal Gap in the Multi-Touch Prototyping Process", die wir auf der Konferenz "Mensch und Computer 2013" in Bremen präsentierten und die mit dem Honorable Mention Paper Award ausgezeichnet wurde, untersuchten wir diesen Sachverhalt für den Prototyping-Prozess von Multi-Touch Anwendungen genauer.
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Investigation of the chemical and sensory properties of red wine pigments.Oberholster, Anita January 2008 (has links)
Phenolic compounds play an important role in red wine colour, bitterness, astringency, as well as a range of other tactile or 'mouth-feel' characteristics. Progressive changes of phenolic compounds, initially extracted from grapes, occur during the storage and aging of red wines. The decrease of astringency occurring during wine aging has been considered as a result of mainly anthocyanin-flavanol condensation either directly or mediated by aldehydes. The contribution of these polymeric pigments formed during wine aging to the unique properties of red wine is an important question still unanswered. Experiments were conducted to synthesise polymeric pigments in model wine solutions under different conditions in the absence of acetaldehyde to provide material for chemical and sensory studies. Only small amounts of polymeric pigments were formed in these experiments confirming that direct polymerisation is a slow process. The low yield of polymers made it necessary to investigate the isolation of polymeric pigments directly from wine. A preparative fractionation protocol was developed to obtain fractions enriched in different red wine pigment combinations for further investigation. A HPLC method was also developed that separated the pigmented and non-pigmented polymers, as well as the monomeric anthocyanins, flavanols (monomeric to trimeric), flavonols and hydroxycinnamic acids from each other. A 6 month old and a 5 year old Shiraz wine were fractionated and further analysed by acid hydrolysis in the presence of a nucleophile, gel permeation chromatography (GPC) and by different mass spectrometry techniques. The various fractions isolated from the 6 month old wine contained combinations of pentameric to dimeric pigments, while those from the 5 year old wine contained pigments with an average degree of polymerisation (DP) of at least 11 but possibly up to 32. Experiments were conducted to determine the sensorial contribution of anthocyanins to wine as well as the effect of anthocyanin-flavanol polymerisation reactions taking place during maturation. It was shown that significant changes occur in the polymeric phenol composition and in the mean degree of polymerisation of Shiraz wine during aging. With aging more skin tannin were incorporated in the pigmented polymers and the percentage of galloylation in these polymers decreased. In order to describe the sensory attributes of the polymeric pigments a refined vocabulary, describing the astringent and other mouth-feel sensations elicited by dry red table wines representing different styles was developed and called the mouth-feel wheel. The developed mouth-feel wheel was used in a study to investigate the contribution of anthocyanins and anthocyanin-proanthocyanidin reaction products to the mouth-feel properties of red wine. Wines were made from both red and white grapes with and without pomace contact, as well as with and without anthocyanin addition to the white grapes. The white wine made like a red wine did not exhibit the same mouth-feel sensory attributes of a red wine: it was lower in viscosity, less particulate in nature and lower in intensity for the astringency descriptors fine emery, dry and grippy. The presence of anthocyanins during fermentation appeared to increase the intensity of astringency related terms. Treatments with added anthocyanins increased the amount of polymeric phenols to twice that when compared to treatments without added anthocyanins. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1345103 / Thesis (Ph.D.) - University of Adelaide, School of Agriculture, Food and Wine, 2008
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Multi-sensory appreciation and practice : a somaesthetic approach to the exploration of taste smell and touch in food-based artNyangiro, Everlyn Akinyi January 2016 (has links)
Even though food-based artworks are no longer a new occurrence within art practice, the particular practice of food that uses taste, smell and touch as artistic medium is still relatively new. This practice poses new challenges at both the creative and receptive ends: for the audience the challenge is linked to understanding and relating with the artwork while for the artist it involves directing the audience’s engagement. Under the theoretical lens of Somaesthetics and Langer’s Mindfulness discourse, this thesis has examined what it means to appreciate food-based artworks through taste, smell and touch. It has also investigated ways in which this form of practice can be developed further. Practice within the research has been used as a means of thinking through the creative choices taken by artists with the purpose of understanding how perceptibility and engagement with food-based works through taste, smell and touch can be enhanced. Some of the key references include Miwa Koizumi’s NY flavors, Burkhard Bacher & Herbert Hinter’s Landscape, Maki Ueda’s Aromascape, and several works by Sam Bompas and Harry Parr amongst others. The outcome of the research include: the development of an attentive discourse of appreciation which outlines the conditions necessary for the appreciation of food-based artwork through its taste, smell and touch; and the articulation of creative strategies that can be used by artists to enhance the perceptibility of taste, smell and touch and encourage engagement. The contributions to knowledge made by this thesis include: The introduction of a new genre of food-based practice; the use of Somaesthetics and Mindfulness as a lens to examine the appreciation of food-based art; the identification of new concerns within practice facing artists using food’s taste, smell and touch as medium; and the new form of encounter with art that requires a mindful-somatic attentiveness.
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Wo ist das Gefühl?: Auf das Aussehen fokussierte Gestaltung interaktiver Anwendungen fim frühen EntwicklungsprozessFreitag, Georg, Wacker, Markus 27 May 2014 (has links)
"Das Programm sieht ja nicht nur gut aus, es macht auch genau das was ich will!" - solche oder ähnliche Aussagen liest man oft, wenn Software-Programme von Anwendern beurteilt werden. Was Nutzer damit beschreiben ist weitestgehend als Look & Feel einer Anwendung bekannt. Der Begriff Look bezieht sich dabei auf die visuellen Bestandteile der Anwendung, wie die genutzten Medienelemente und deren Layout. Das Themenfeld Feel umfasst das interaktive Verhalten einer Anwendung, die auf Eingaben des Nutzers reagiert (Feedback) oder bereits vorher Hinweise auf die eigene Verwendbarkeit gibt (Feed-Forward). Allgemein gilt, je interaktiver eine Anwendung, desto wichtiger ist das "Gefühl" im Look & Feel. Als Beispiel dienen die sogenannten natürlichen Benutzerschnittstellen (NUI), wie die sich in den letzten Jahren enorm verbreitende Form des Multi-Touches. Bei dieser interagiert der Nutzer direkt mit der Anwendung ohne separate Eingabegeräte als Vermittler seiner Aktionen. Eine weitere Charakteristik dieser Benutzerschnittstellen ist deren intuitive Verwendbarkeit. Dies bedeutet, dass sich während der Interaktion mit den Programmen deren Strukturen und Funktionen von selbst erschließen. Um dies zu gewährleisten ist die sorgsame Gestaltung des Feels von Beginn der Entwicklung an bedeutsam. Umso überraschender ist das Ergebnis unseres Vergleichs aktueller Prototyping-Werkzeuge für Benutzeroberflächen, die den Aspekt Feel oftmals nicht oder nur unzureichend berücksichtigen und stattdessen das Aussehen (Look) einer Anwendung fokussieren. In unserer kürzlich erschienenen Arbeit "Look without Feel - A Basal Gap in the Multi-Touch Prototyping Process", die wir auf der Konferenz "Mensch und Computer 2013" in Bremen präsentierten und die mit dem Honorable Mention Paper Award ausgezeichnet wurde, untersuchten wir diesen Sachverhalt für den Prototyping-Prozess von Multi-Touch Anwendungen genauer.
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