Academic literature on the topic 'Function-task-behaviour'
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Journal articles on the topic "Function-task-behaviour"
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Flanagan, J. Randall, Gerben Rotman, Andreas F. Reichelt, and Roland S. Johansson. "The role of observers' gaze behaviour when watching object manipulation tasks: predicting and evaluating the consequences of action." Philosophical Transactions of the Royal Society B: Biological Sciences 368, no. 1628 (October 19, 2013): 20130063. http://dx.doi.org/10.1098/rstb.2013.0063.
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When watching an actor manipulate objects, observers, like the actor, naturally direct their gaze to each object as the hand approaches and typically maintain gaze on the object until the hand departs. Here, we probed the function of observers' eye movements, focusing on two possibilities: (i) that observers' gaze behaviour arises from processes involved in the prediction of the target object of the actor's reaching movement and (ii) that this gaze behaviour supports the evaluation of mechanical events that arise from interactions between the actor's hand and objects. Observers watched an actor reach for and lift one of two presented objects. The observers' task was either to predict the target object or judge its weight. Proactive gaze behaviour, similar to that seen in self-guided action–observation, was seen in the weight judgement task, which requires evaluating mechanical events associated with lifting, but not in the target prediction task. We submit that an important function of gaze behaviour in self-guided action observation is the evaluation of mechanical events associated with interactions between the hand and object. By comparing predicted and actual mechanical events, observers, like actors, can gain knowledge about the world, including information about objects they may subsequently act upon.
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Johnson, Leif, Brian Sullivan, Mary Hayhoe, and Dana Ballard. "Predicting human visuomotor behaviour in a driving task." Philosophical Transactions of the Royal Society B: Biological Sciences 369, no. 1636 (February 19, 2014): 20130044. http://dx.doi.org/10.1098/rstb.2013.0044.
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The sequential deployment of gaze to regions of interest is an integral part of human visual function. Owing to its central importance, decades of research have focused on predicting gaze locations, but there has been relatively little formal attempt to predict the temporal aspects of gaze deployment in natural multi-tasking situations. We approach this problem by decomposing complex visual behaviour into individual task modules that require independent sources of visual information for control, in order to model human gaze deployment on different task-relevant objects. We introduce a softmax barrier model for gaze selection that uses two key elements: a priority parameter that represents task importance per module, and noise estimates that allow modules to represent uncertainty about the state of task-relevant visual information. Comparisons with human gaze data gathered in a virtual driving environment show that the model closely approximates human performance.
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MARUFF, P., R. PURCELL, P. TYLER, C. PANTELIS, and J. CURRIE. "Abnormalities of internally generated saccades in obsessive–compulsive disorder." Psychological Medicine 29, no. 6 (November 1999): 1377–85. http://dx.doi.org/10.1017/s0033291799008843.
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Background. We aimed to utilize tests of saccadic function to investigate whether cognitive abnormalities in obsessive–compulsive disorder (OCD) arise from a dysfunction of inhibitory processes or whether they reflect a more general difficulty in guiding behaviour on the basis of an internal representation of task goal.Methods. Twelve patients with OCD and 12 matched controls performed a visually-guided saccade task, a volitional prosaccade task and an antisaccade task. The latency and gain of saccades was compared between groups for the three saccade tasks. The number of antisaccade errors was also calculated and compared between groups.Results. There was no difference for antisaccade error rates between the groups. The latency of visually guided saccades did not differ between groups, however the latency of both volitional prosaccades and antisaccades was significantly slower in the patients with OCD than in controls. The difference in latency between volitional prosacades and antisaccades, however, was equal between groups.Conclusions. These results suggest that patients with OCD have an abnormality in guiding behaviour on the basis of an internal representation of the task goal, rather than a problem with inhibiting reflexive behaviour.
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Waller, B. M., A. Misch, J. Whitehouse, and E. Herrmann. "Children, but not chimpanzees, have facial correlates of determination." Biology Letters 10, no. 3 (March 2014): 20130974. http://dx.doi.org/10.1098/rsbl.2013.0974.
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Facial expressions have long been proposed to be important agents in forming and maintaining cooperative interactions in social groups. Human beings are inordinately cooperative when compared with their closest-living relatives, the great apes, and hence one might expect species differences in facial expressivity in contexts in which cooperation could be advantageous. Here, human children and chimpanzees were given an identical task designed to induce an element of frustration (it was impossible to solve). In children, but not chimpanzees, facial expressions associated with effort and determination positively correlated with persistence at the task. By contrast, bodily indicators of stress (self-directed behaviour) negatively correlated with task persistence in chimpanzees. Thus, children exhibited more behaviour as they persisted, and chimpanzees exhibited less. The facial expressions produced by children, could, therefore, function to solicit prosocial assistance from others.
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Sun, Xiaoguang, Rémy Houssin, Jean Renaud, and Mickaël Gardoni. "Towards a human factors and ergonomics integration framework in the early product design phase: Function-Task-Behaviour." International Journal of Production Research 56, no. 14 (February 13, 2018): 4941–53. http://dx.doi.org/10.1080/00207543.2018.1437287.
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Ma, Jasmin K., Lucy Le Mare, and Brendon J. Gurd. "Four minutes of in-class high-intensity interval activity improves selective attention in 9- to 11-year olds." Applied Physiology, Nutrition, and Metabolism 40, no. 3 (March 2015): 238–44. http://dx.doi.org/10.1139/apnm-2014-0309.
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The amount of time allocated to physical activity in schools is declining. Time-efficient physical activity solutions that demonstrate their impact on academic achievement-related outcomes are needed to prioritize physical activity within the school curricula. “FUNtervals” are 4-min, high-intensity interval activities that use whole-body actions to complement a storyline. The purpose of this study was to (i) explore whether FUNtervals can improve selective attention, an executive function posited to be essential for learning and academic success; and (ii) examine whether this relationship is predicted by students’ classroom off-task behaviour. Seven grade 3–5 classes (n = 88) were exposed to a single-group, repeated cross-over design where each student’s selective attention was compared between no-activity and FUNtervals days. In week 1, students were familiarized with the d2 test of attention and FUNterval activities, and baseline off-task behaviour was observed. In both weeks 2 and 3 students completed the d2 test of attention following either a FUNterval break or a no-activity break. The order of these breaks was randomized and counterbalanced between weeks. Neither motor nor passive off-task behaviour predicted changes in selective attention following FUNtervals; however, a weak relationship was observed for verbal off-task behaviour and improvements in d2 test performance. More importantly, students made fewer errors during the d2 test following FUNtervals. In supporting the priority of physical activity inclusion within schools, FUNtervals, a time efficient and easily implemented physical activity break, can improve selective attention in 9- to 11-year olds.
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Barkus, Chris, Jacqueline-Marie N. Ferland, Wendy K. Adams, Grant C. Churchill, Philip J. Cowen, David M. Bannerman, Robert D. Rogers, Catharine A. Winstanley, and Trevor Sharp. "The putative lithium-mimetic ebselen reduces impulsivity in rodent models." Journal of Psychopharmacology 32, no. 9 (July 10, 2018): 1018–26. http://dx.doi.org/10.1177/0269881118784876.
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Background: Deficits in impulse control feature in many psychiatric conditions including bipolar disorder, suicidality and addictions. Lithium lowers impulsivity in clinical populations and decreases pathological gambling in experimental medicine studies, but suffers from adverse effects, poor compliance and a low therapeutic index. Aims: Recently we identified that the neuroprotective agent ebselen, which is reportedly safe in humans, inhibited inositol monophosphatase (IMPase), a candidate lithium mechanism. Ebselen also reduced 5-HT receptor (5-HT2A) function which predicts impulsivity lowering properties. Here we investigated the effect of ebselen in rat models of impulsive behaviour. Methods: Ebselen was tested in two models of impulsivity with human analogues: the five-choice serial reaction time task (5-CSRTT) and rodent gambling task (rGT). The main outcome measures were premature responses (5-CSRTT and rGT) and choice behaviour (rGT), which model motor impulsivity and choice impulsivity, respectively. Results: At doses that decreased 5-HT2A receptor function (DOI-induced wet dog shakes), ebselen decreased premature responding in the 5-CSRTT both in the absence and presence of cocaine. The 5-HT2A receptor antagonist MDL 100,907 also reduced premature responding in the 5-CSRTT although not in the presence of cocaine. In the rGT ebselen showed a tendency to reduce premature responding but had no effect on choice behaviour. Conclusions: These findings suggest that ebselen preferentially reduces motor impulsivity over choice impulsivity, and that inhibition of 5-HT2A receptor function is a contributing mechanism. Collectively, these data support the repurposing of ebselen as an anti-impulsive treatment and fast-tracking to clinical trials in patient groups characterised by poor impulse control.
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Pascual-Leone, Alvaro. "Transcranial magnetic stimulation: studying the brain--behaviour relationship by induction of ‘virtual lesions’." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 354, no. 1387 (July 29, 1999): 1229–38. http://dx.doi.org/10.1098/rstb.1999.0476.
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Transcranial magnetic stimulation (TMS) provides a non-invasive method of induction of a focal current in the brain and transient modulation of the function of the targeted cortex. Despite limited understanding about focality and mechanisms of action, TMS provides a unique opportunity of studying brain-behaviour relations in normal humans. TMS can enhance the results of other neuroimaging techniques by establishing the causal link between brain activity and task performance, and by exploring functional brain connectivity.
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Filippi, Roberto, Andrea Ceccolini, Eva Periche-Tomas, and Peter Bright. "Developmental trajectories of metacognitive processing and executive function from childhood to older age." Quarterly Journal of Experimental Psychology 73, no. 11 (June 13, 2020): 1757–73. http://dx.doi.org/10.1177/1747021820931096.
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The modern understanding of the term metacognition encompasses two levels of processing: a lower level awareness or knowledge of one’s own thoughts and a higher level regulation or control of our thinking. Metacognition, therefore, bears conceptual similarity with executive function: both are concerned with top-down monitoring and control of cognition in the service of ongoing goal-directed behaviour. Previous studies have shown a possible executive function advantage in multilingual speakers but also a possible disadvantage in metacognitive processing. To progress theory on metacognitive processing and the relationship with executive function and linguistic experience across the lifespan, we conducted a study testing 330 healthy individuals in four age groups from 7 to 80 years old. All participants performed a metacognition task and two measures of executive function, which included the Simon task and the Tower of London task. Half the participants were multilingual speakers since birth. We built developmental trajectories of metacognitive and executive function across the lifespan. The best metacognitive efficiency was observed in mid-adulthood, whereas the best executive function processing reached its peak in young adulthood. A steep cognitive decline was observed in older age, while metacognitive efficiency was preserved. Exploratory factor analysis indicated that metacognition and executive function are served by different factors across all ages. Contrary to previous findings in the bilingual literature, a multilinguistic experience conferred neither any significant advantage nor disadvantage in both executive function and metacognitive processing across the lifespan.
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Lambert, Megan L., Martina Schiestl, Raoul Schwing, Alex H. Taylor, Gyula K. Gajdon, Katie E. Slocombe, and Amanda M. Seed. "Function and flexibility of object exploration in kea and New Caledonian crows." Royal Society Open Science 4, no. 9 (September 2017): 170652. http://dx.doi.org/10.1098/rsos.170652.
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A range of non-human animals frequently manipulate and explore objects in their environment, which may enable them to learn about physical properties and potentially form more abstract concepts of properties such as weight and rigidity. Whether animals can apply the information learned during their exploration to solve novel problems, however, and whether they actually change their exploratory behaviour to seek functional information about objects have not been fully explored. We allowed kea ( Nestor notabilis ) and New Caledonian crows ( Corvus moneduloides ) to explore sets of novel objects both before and after encountering a task in which some of the objects could function as tools. Following this, subjects were given test trials in which they could choose among the objects they had explored to solve a tool-use task. Several individuals from both species performed above chance on these test trials, and only did so after exploring the objects, compared with a control experiment with no prior exploration phase. These results suggest that selection of functional tools may be guided by information acquired during exploration. Neither kea nor crows changed the duration or quality of their exploration after learning that the objects had a functional relevance, suggesting that birds do not adjust their behaviour to explicitly seek this information.
Dissertations / Theses on the topic "Function-task-behaviour"
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Sun, Xiaoguang. "Une approche innovante basée sur un cadre de fonction-tâche-comportement pour intégrer les facteurs humains et l'ergonomie dès la première phase de conception." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAD044/document.
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Les facteurs humains et l’ergonomie (HF/E) sont devenus une discipline scientifique fournissant des contraintes pour la conception d’interaction entre l’homme et le système (le produit). La plupart des études sur HF/E couvrent non seulement les aspects d’ergonomie physique, mais aussi les sciences cognitives et organisationnelle. De nombreux travaux attestent que l’intégration insuffisante d’informations HF/E mène à une conception « pauvre ». Intégrer que ces informations de la phase de conception peuvent améliorer la performance du produit ou du système et de l’expérience utilisateur. Les méthodes existantes pour l’intégration de l’information HF/E (HF/EII) sont catégorisées par deux types de conception : la conception Centrée sur la Technologie (TCD) et la conception Centrée sur l’Utilisateur (UCD). Les méthodes TCD intègrent des informations HF/E dans la phase de conception détaillée ou plus tard, ce qui peut causer des modifications et des itérations de conception. Par contre, les approches UCD prennent en considération les informations HF/E dès la première phase de conception et sont consommatrices de temps à cause de l’intégration des exigences HF/E. L’objectif de cette thèse est de développer une nouvelle méthodologie de conception et un outil pour l’intégration de HF/E dès la première phase de conception dans le but de réduire le temps de conception, notamment en ayant moins de boucles itératives. Au cours de ce travail de recherche, un cadre « fonction-tâche-comportement » (FTB) a été développé, fournissant un guide systématique et détaillé pour l’intégration de HF/E dès la première phase de conception. Une étude de cas est présentée pour valider la faisabilité de la méthode et permettre une assistance pour la mise en œuvre. Ainsi, un module de Centre de Conception d’Interaction (IDC) a été développé et intégré dans un logiciel de CAO pour aider le travail de conception, en fournisant une procédure pratique de mise en œuvre du cadre FTB. Il permet aux concepteurs (1) d’intégrer les exigences fonctionnelles et non fonctionnelles dès la première phase de conception, et (2) de les convertir en des paramètres de conception pour effectuer au mieux le travail de conception. En utilisant le module d’IDC, les modifications et les boucles d’itération de conception peuvent être significativement réduits, fournissant ainsi une expérience utilisateur plus satisfaisante lors du respects les exigences fonctionnelles. De plus, les méthodologies actuelles de génération de solutions de conception s’appuient trop sur l’expérience des concepteurs, c’est pourquoi un « modèle de d’aide à la génération de solution » a commencé à être développé pour produire les solutions de conception recherchées. Différentes approches de résolution de problèmes existent, ce modèle proposé est plus facile à appréhender et à utiliser par les concepteurs. Ce modèle offre une pensée divergente pour la génération de solution de conception basée sur la tâche de conception individuelle. En résumé, dans les conclusions, les contributions majeures et les limitations de notre étude sont présentées et les perspectives de recherche future sont proposéesHuman factors and ergonomics (HF/E) as a scientific discipline provide constraints for the engineering design of human and system (product) interactions. Most existing studies on HF/E cover the specialization of physical, cognitive, and organizational ergonomics. Numerous evidences show that insufficient consideration of HF/E information leads to poor design, and fully considering this information in the design phase can improve both the user experience and system performance. Existing methods for HF/E information integration (HF/EII) can be categorized into two types: Technology-Centred Design (TCD) and User-Centred Design (UCD). TCD methods integrate HF/E information from the detailed design phase or later, which may cause design modifications and iterations. UCD approaches address HF/E information from the early design phase, which are time-consuming for HF/E requirements collection. The objective of this thesis is dedicated to a new design methodology and tool for HF/EII from the early design phase in a systematic, time-saving, less expensive, and less iteration way. In this thesis, a function-task-behaviour framework has been developed, which provides a systematic and detailed guide for HF/EII from the early design phase. A case study has been presented to validate its feasibility, which offers the theoretical support for method implementation. Thus, an Interaction Design Centre (IDC) module was developed and integrated in CAD software to aid the design work, which provides a practical way for the implementation of FTB framework. It enables designers to (1) catch both functional requirements and non-functional requirements from the early design phase, and (2) convert them into design parameters to carry out the design work. By using IDC module, design modifications and iterations due to belated effort for HF/E consideration can be significantly reduced, thereby providing a satisfactory user experience in the case of meeting the functional requirements. Regarding current method of design solution generation overly relies on designers’ experience, a design solution generation model is developed for producing design solution. Different from current problem solving approaches, this model is easy for designers to cognize and operate. It offers a divergent thinking for design solution generation based on the individual design task. Finally, the major contributions and limitations of our study are presented and the future studies are previewed
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Popken, Anke. "Drivers’ reliance on lane keeping assistance systems as a function of the level of assistance." Doctoral thesis, Universitätsbibliothek Chemnitz, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-201000382.
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Fahrerassistenzsysteme werden zunehmend in Fahrzeuge eingebaut mit dem Ziel, den Fahrer beim Fahren zu unterstützen, Fahrfehler zu vermeiden und damit die Fahrsicherheit zu erhöhen. Derzeit sind häufig Systeme im Einsatz, die den Fahrer vor bestimmten Sicherheitsrisiken warnen (z.B. vor einem unbeabsichtigten Verlassen der Fahrspur). Der Trend geht aber hin zu Systemen, die stärker ins Fahrgeschehen eingreifen und somit Teile der Fahraufgabe automatisieren (z.B. selbständig die Spurhaltung des Fahrzeugs übernehmen). Aus der Forschung zur Mensch-Maschine Interaktion ist jedoch bekannt, dass Automatisierung nicht zwangsläufig zur Erhöhung von Sicherheit führt, sondern dass sie vielmehr auch unerwünschte Nebeneffekte für Performanz und Sicherheit mit sich bringen kann in dem Maße, wie Menschen an die veränderten Aufgabenanforderungen adaptieren. Im Straßenverkehr wird insbesondere befürchtet, dass Fahrer sich zu stark auf Fahrerassistenzsysteme verlassen, sich teilweise aus der Fahraufgabe zurückziehen („abschalten“) und ihre Aufmerksamkeit fahrfremden Dingen widmen. Dies kann unter Umständen dazu führen, dass Fahrer im Falle von Systemfehlern oder –ausfällen nicht mehr in der Lage sind rechtzeitig und angemessen einzugreifen bzw. die Kontrolle über das Fahrzeug zu übernehmen. Ziel der Dissertation war es zu untersuchen, inwieweit sich die Involviertheit von Fahrern in die Fahraufgabe verändert je stärker sie durch ein Assistenzsystem unterstützt werden (d.h., je stärker das System Teile der Fahraufgabe automatisiert). Um dies zu untersuchen wurden zwei theoretische Konzepte herangezogen: a) das Verlassen der Fahrer (auf ein System) und b) das Situationsbewusstsein der Fahrer. Basierend auf einer umfassenden Analyse der Forschungsliteratur zum Thema Automatisierung wurde ein theoretisches Rahmenmodell entwickelt, welches Veränderungen in der Involviertheit des Fahrers in die Fahraufgabe auf menschliche Adaptationsprozesse auf verschiedenen Ebenen zurückführt, die sich in Folge der veränderten Aufgabenanforderungen durch zunehmende Automatisierung ergeben. Dazu zählen Veränderungen in Einstellungen, sowie in kognitiven, energetischen, und motivationalen Prozessen. Um Veränderungen in diesen Prozessen zu untersuchen, wurde eine Vielzahl an objektiven und subjektiven Maßen erhoben. Hauptgegenstand der Dissertation ist eine umfangreiche Fahrsimulatorstudie im Fahrsimulator mit Bewegungsplattform bei VTI (Swedish National Road and Transport Research Institute) in Linköping, Schweden. Dabei kamen zwei Querführungsassistenzsysteme (ein Heading Control System und ein Lane Departure Warning System) zum Einsatz, die den Fahrer in unterschiedlichem Maße bei der Spurhaltung unterstützten. Im Gegensatz zu einem Großteil der bisherigen Studien wurden prozessorientierte Performanzmaße zur Erfassung des Verlassens der Fahrer auf die Assistenzsysteme und des Situationsbewusstseins der Fahrer verwendet. Das Verlassen der Fahrer auf die Querführungsassistenzsysteme wurde durch Blickverhaltensmaße über die Bereitschaft der Fahrer erfasst, ihre visuelle Aufmerksamkeit von der Straße ab hin zu einer Zweitaufgabe im Fahrzeuginnenraum zu wenden. Zur Messung des Situationsbewusstseins der Fahrer wurden Fahrverhaltensmaße herangezogen welche als Indikator für die Schnelligkeit und Abruptheit der Reaktionen der Fahrer auf unerwartete kritische Fahrsituationen dienten. Ein Hauptbefund der Dissertation war, dass die Fahrer sich signifikant im Ausmaß ihres Verlassens auf einen hohen Grad an Assistenz unterschieden. Diese interindividuelle Varianz im Verlassen der Fahrer auf einen hohen Grad an Assistenz konnte am besten durch das Vertrauen der Fahrer in das Querführungsassistenzsystem und ihr Aktivierungsniveau erklärt werden: Je höher das Vertrauen der Fahrer in das System und je geringer ihr Aktivierungsniveau, desto stärker verließen sie sich auf das System. Individuelle Fahrermerkmale (Fahrstil) erklärten einen signifikanten Anteil der Varianz im Vertrauen der Fahrer in die Spurhalteassistenzsysteme. (ersetzt wegen neuem Herausgeber)Advanced driver assistance systems are increasingly built in vehicles with the aim to support drivers while driving, to reduce driver errors and thereby to increase traffic safety. At present, these systems are often designed to warn drivers of specific safety risks (e.g., of an imminent departure from the driving lane). However, there is a trend towards systems that more strongly intervene in driving and that hence, automate parts of the driving task (e.g., autonomously keep the vehicle within the driving lane). However, research on human-machine interaction has shown that automation does not necessarily increase safety, but that it may also lead to unanticipated side effects on performance and safety to the extent that humans adapt to the changing task demands. A major concern in road traffic is that drivers rely too heavily on driver assistance systems, become less actively involved in the driving task, and divert their attention to things unrelated to driving. Thus, in the case of system malfunctions or failures, drivers possibly may not be prepared to intervene timely and accordingly and to regain control over the vehicle, respectively. The aim of this dissertation was to investigate changes in drivers’ active engagement in the driving task as a function of the degree to which they are supported by a driver assistance system (i.e., as a function of the degree to which the system automates the driving task). Drivers’ active task engagement was studied by referring to two theoretical concepts: a) drivers’ reliance (on a system) and b) drivers’ situation awareness. Based on an extensive review of previous research on automation, a conceptual theoretical framework was developed that links changes in operators’ active task engagement to human adaptation processes on different levels in response to the changing task demands due to automation. Among them are changes in human attitudes as well as in cognitive, motivational and energetic processes. In order to determine the relative influence of these processes, a range of objective and subjective measures was collected. The essential part of the dissertation is an extensive driving simulator study in an advanced moving-base driving simulator at VTI (Swedish National Road and Transport Research Institute) in Linköping, Sweden. Two lateral support systems (a Heading Control system and a Lane Departure Warning system) were implemented which assisted drivers to different degrees in lane keeping. Contrary to most previous automation studies, drivers’ reliance on the lane keeping assistance systems and their situation awareness were studied by using process-oriented performance-based measures. Drivers’ reliance on the lane keeping assistance systems was assessed by eye glance behaviour measures indicating drivers’ preparedness to allocate their visual attention away from the road scene to an in-vehicle secondary task. Drivers’ situation awareness was assessed by behavioural measures of the latency and magnitude of drivers’ initial reactions to unexpected critical driving situations. A major finding of the study was that drivers differed significantly in their reliance on a high level of lane keeping assistance. This interindividual variance in drivers’ reliance on higher-level assistance could be best explained by drivers’ trust in the system and their energetic arousal: The greater drivers’ trust in the system and the lower their arousal, the more did they rely on the system. Individual driver variables (driving style) explained a significant proportion of the variance in drivers’ trust in the lane keeping assistance systems. (replaced because a new publisher)
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Popken, Anke. "Drivers’ reliance on lane keeping assistance systems as a function of the level of assistance." Doctoral thesis, 2009. https://monarch.qucosa.de/id/qucosa%3A19288.
Full textAbstract:
Fahrerassistenzsysteme werden zunehmend in Fahrzeuge eingebaut mit dem Ziel, den Fahrer beim Fahren zu unterstützen, Fahrfehler zu vermeiden und damit die Fahrsicherheit zu erhöhen. Derzeit sind häufig Systeme im Einsatz, die den Fahrer vor bestimmten Sicherheitsrisiken warnen (z.B. vor einem unbeabsichtigten Verlassen der Fahrspur). Der Trend geht aber hin zu Systemen, die stärker ins Fahrgeschehen eingreifen und somit Teile der Fahraufgabe automatisieren (z.B. selbständig die Spurhaltung des Fahrzeugs übernehmen). Aus der Forschung zur Mensch-Maschine Interaktion ist jedoch bekannt, dass Automatisierung nicht zwangsläufig zur Erhöhung von Sicherheit führt, sondern dass sie vielmehr auch unerwünschte Nebeneffekte für Performanz und Sicherheit mit sich bringen kann in dem Maße, wie Menschen an die veränderten Aufgabenanforderungen adaptieren. Im Straßenverkehr wird insbesondere befürchtet, dass Fahrer sich zu stark auf Fahrerassistenzsysteme verlassen, sich teilweise aus der Fahraufgabe zurückziehen („abschalten“) und ihre Aufmerksamkeit fahrfremden Dingen widmen. Dies kann unter Umständen dazu führen, dass Fahrer im Falle von Systemfehlern oder –ausfällen nicht mehr in der Lage sind rechtzeitig und angemessen einzugreifen bzw. die Kontrolle über das Fahrzeug zu übernehmen.
Ziel der Dissertation war es zu untersuchen, inwieweit sich die Involviertheit von Fahrern in die Fahraufgabe verändert je stärker sie durch ein Assistenzsystem unterstützt werden (d.h., je stärker das System Teile der Fahraufgabe automatisiert). Um dies zu untersuchen wurden zwei theoretische Konzepte herangezogen: a) das Verlassen der Fahrer (auf ein System) und b) das Situationsbewusstsein der Fahrer. Basierend auf einer umfassenden Analyse der Forschungsliteratur zum Thema Automatisierung wurde ein theoretisches Rahmenmodell entwickelt, welches Veränderungen in der Involviertheit des Fahrers in die Fahraufgabe auf menschliche Adaptationsprozesse auf verschiedenen Ebenen zurückführt, die sich in Folge der veränderten Aufgabenanforderungen durch zunehmende Automatisierung ergeben. Dazu zählen Veränderungen in Einstellungen, sowie in kognitiven, energetischen, und motivationalen Prozessen. Um Veränderungen in diesen Prozessen zu untersuchen, wurde eine Vielzahl an objektiven und subjektiven Maßen erhoben.
Hauptgegenstand der Dissertation ist eine umfangreiche Fahrsimulatorstudie im Fahrsimulator mit Bewegungsplattform bei VTI (Swedish National Road and Transport Research Institute) in Linköping, Schweden. Dabei kamen zwei Querführungsassistenzsysteme (ein Heading Control System und ein Lane Departure Warning System) zum Einsatz, die den Fahrer in unterschiedlichem Maße bei der Spurhaltung unterstützten. Im Gegensatz zu einem Großteil der bisherigen Studien wurden prozessorientierte Performanzmaße zur Erfassung des Verlassens der Fahrer auf die Assistenzsysteme und des Situationsbewusstseins der Fahrer verwendet. Das Verlassen der Fahrer auf die Querführungsassistenzsysteme wurde durch Blickverhaltensmaße über die Bereitschaft der Fahrer erfasst, ihre visuelle Aufmerksamkeit von der Straße ab hin zu einer Zweitaufgabe im Fahrzeuginnenraum zu wenden. Zur Messung des Situationsbewusstseins der Fahrer wurden Fahrverhaltensmaße herangezogen welche als Indikator für die Schnelligkeit und Abruptheit der Reaktionen der Fahrer auf unerwartete kritische Fahrsituationen dienten.
Ein Hauptbefund der Dissertation war, dass die Fahrer sich signifikant im Ausmaß ihres Verlassens auf einen hohen Grad an Assistenz unterschieden. Diese interindividuelle Varianz im Verlassen der Fahrer auf einen hohen Grad an Assistenz konnte am besten durch das Vertrauen der Fahrer in das Querführungsassistenzsystem und ihr Aktivierungsniveau erklärt werden: Je höher das Vertrauen der Fahrer in das System und je geringer ihr Aktivierungsniveau, desto stärker verließen sie sich auf das System. Individuelle Fahrermerkmale (Fahrstil) erklärten einen signifikanten Anteil der Varianz im Vertrauen der Fahrer in die Spurhalteassistenzsysteme.
(ersetzt wegen neuem Herausgeber)Advanced driver assistance systems are increasingly built in vehicles with the aim to support drivers while driving, to reduce driver errors and thereby to increase traffic safety. At present, these systems are often designed to warn drivers of specific safety risks (e.g., of an imminent departure from the driving lane). However, there is a trend towards systems that more strongly intervene in driving and that hence, automate parts of the driving task (e.g., autonomously keep the vehicle within the driving lane). However, research on human-machine interaction has shown that automation does not necessarily increase safety, but that it may also lead to unanticipated side effects on performance and safety to the extent that humans adapt to the changing task demands. A major concern in road traffic is that drivers rely too heavily on driver assistance systems, become less actively involved in the driving task, and divert their attention to things unrelated to driving. Thus, in the case of system malfunctions or failures, drivers possibly may not be prepared to intervene timely and accordingly and to regain control over the vehicle, respectively. The aim of this dissertation was to investigate changes in drivers’ active engagement in the driving task as a function of the degree to which they are supported by a driver assistance system (i.e., as a function of the degree to which the system automates the driving task). Drivers’ active task engagement was studied by referring to two theoretical concepts: a) drivers’ reliance (on a system) and b) drivers’ situation awareness. Based on an extensive review of previous research on automation, a conceptual theoretical framework was developed that links changes in operators’ active task engagement to human adaptation processes on different levels in response to the changing task demands due to automation. Among them are changes in human attitudes as well as in cognitive, motivational and energetic processes. In order to determine the relative influence of these processes, a range of objective and subjective measures was collected. The essential part of the dissertation is an extensive driving simulator study in an advanced moving-base driving simulator at VTI (Swedish National Road and Transport Research Institute) in Linköping, Sweden. Two lateral support systems (a Heading Control system and a Lane Departure Warning system) were implemented which assisted drivers to different degrees in lane keeping. Contrary to most previous automation studies, drivers’ reliance on the lane keeping assistance systems and their situation awareness were studied by using process-oriented performance-based measures. Drivers’ reliance on the lane keeping assistance systems was assessed by eye glance behaviour measures indicating drivers’ preparedness to allocate their visual attention away from the road scene to an in-vehicle secondary task. Drivers’ situation awareness was assessed by behavioural measures of the latency and magnitude of drivers’ initial reactions to unexpected critical driving situations. A major finding of the study was that drivers differed significantly in their reliance on a high level of lane keeping assistance. This interindividual variance in drivers’ reliance on higher-level assistance could be best explained by drivers’ trust in the system and their energetic arousal: The greater drivers’ trust in the system and the lower their arousal, the more did they rely on the system. Individual driver variables (driving style) explained a significant proportion of the variance in drivers’ trust in the lane keeping assistance systems. (replaced because a new publisher)
Books on the topic "Function-task-behaviour"
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Catney, Ruth. Emotion as context in the A-not-B task: Infants' search behaviour as a function of distress. Ottawa: National Library of Canada, 1996.
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Birch, Jonathan. Conceptualizing Social Behaviour. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198733058.003.0001.
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Hamilton classified social behaviours by the sign of their effects on the reproductive success of the actor and the recipient, leading to a four-part schema that categorizes behaviour as altruistic, selfish, mutually beneficial, or spiteful. While broadly endorsing Hamilton’s approach, this chapter argues that we should categorize social behaviour in terms of the selection processes that have maintained the behaviour in recent evolutionary history. Given its close affinity with a recent history theory of function, this approach faces objections that parallel the well-known objections to that theory, but parallel responses are also available. This chapter further argues that the classification of an action should be (i) strategy-relative and (ii) task-relative.
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Kar, Robin Bradley, and John Lindo. Race and the Law in the Genomic Age. Edited by Roger Brownsword, Eloise Scotford, and Karen Yeung. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780199680832.013.55.
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Despite the ‘Age of Genomics’, many scholars who study race and the law resist biological insights into human psychology and behaviour. Contemporary developments make this resistance increasingly untenable. This chapter synthesizes recent findings in genomics and evolutionary psychology, which suggest cause for concern over how racial concepts function in the law. Firstly, racial perceptions engage a ‘folk-biological’ module of psychology, which generates inferences poorly adapted to genomic facts about human populations. Racial perceptions are, therefore, prone to function in ways more prejudicial than probative of many issues relevant to criminal and civil liability. Secondly, many folk biological inferences function automatically, unconsciously, and without animus or discriminatory intent. Hence, current equal protection doctrine, which requires a finding of discriminatory intent and is a central mechanism for guaranteeing people equal treatment under the law, is poorly suited to that task. These facts support but complicate several claims made by Critical Race Theorists.
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Shea, Nicholas. Standard Objections. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198812883.003.0006.
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Varitel semantics has several resources for dealing with indeterminacy. It gives rise to more determinate contents than informational semantics or consumer-based teleosemantics. The remaining indeterminacy is a virtue: it is what we should expect in simpler systems with fewer interacting components. Some of the non-conceptual representations in our case studies exhibit some features exemplified by concepts: semantically significant constituent structure; unsaturated components; and limited, domain-specific generality. A historical component is needed to bring into view the explanandum to which representational explanation is directed, namely successful and unsuccessful behaviour. We should not expect representational explanation to get a grip, in these simple cases, without some period in which behavioural outcomes have been stabilized. Even a short period of interaction will establish some task functions and contents. Varitel semantics does not reduce misrepresentation to malfunction. Misrepresentation does not imply failure to perform a task function, nor the converse.
Book chapters on the topic "Function-task-behaviour"
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Swift, Ellen. "Behaviour/Experience." In Roman Artefacts and Society. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198785262.003.0007.
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This chapter explores in depth the way in which the affordances of artefacts constrain or enable specific uses and/or experiences. In the first half of the chapter, we will consider a range of objects and materials from this perspective. We have seen from the previous chapter that evaluating use and behaviour from artefact affordances is not always a straightforward process. Affordances may suit a range of functions. Apparently functional features of artefacts may become redundant as the use of the artefact changes. Use of functional features can change even though the features themselves remain the same—for instance if they afford a range of functions. Aspects of artefact form may relate to task efficiency, rather than whether or not a task can be performed, and so may be ignored when quality of performance is less important. Any attempt to study behaviour through artefact design must engage with these issues, and I have chosen to do this mainly through careful selection of objects. Firstly, we can choose artefacts that performonly a very narrow range of functions in normative use, and in which system function uses may be identifiable through wear marks or changes to the artefact. Secondly, artefact forms can be selected that constrain or enforce particular behaviour, or affect experience in a predictable way. Evidence of affordances will also be studied alongside other types of evidence such as visual sources or contextual information. The objects chosen for investigation in this chapter are cone cups, drinking horns, spoons, strigils, styli, locks and keys (including key finger-rings), and dice. Most of these are artefacts that also exist in modern or more recent historical material culture, and while the benefits of this are obvious in terms of comparisons and an understanding of artefact features through direct experience of similar modern items, we will also need to be aware of any assumptions about the performance of artefacts that may be conditioned by modern perceptions of what an artefact is for, and how it can or should be used.
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Ross, Alf. "[416]Legal Politics: Province and Task." In On Law and Justice, 412–25. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780198716105.003.0015.
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This chapter begins by discussing the line of demarcation between legal politics and other politics. It then covers the theoretical foundation and tasks of legal politics. With regard to the theoretical foundations, it argues that the necessary insight is the juridico-sociological knowledge of the causal connection between legal regulation and human behaviour; or the insight into the issue of how it is possible to influence human behaviour through the function of legal machinery—which, in turn, is determined by legal regulations. With regard to the tasks of legal politics, it argues that the first task is to examine the attitudes and objectives that are currently prevalent in influential social groups, and thereby determinative of the organs that have the formal power to legislate. The next step in a juridico-political inquiry is to describe the juridico-sociological facts and contexts operative in relation to the premise. The third and last step in the juridico-political investigation is the formulation of conclusions in the form of instructions to the legislator or the judge.
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Barnes, Jonathan. "17. Teleology." In Aristotle: A Very Short Introduction, 116–22. Oxford University Press, 2000. http://dx.doi.org/10.1093/actrade/9780192854087.003.0017.
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Aristotle had a teleological view of nature. Natural behaviour and natural structure usually have final causes, but these are constrained by necessity: nature does the best she can ‘in the circumstances’. Aristotle’s teleology is sometimes summed up in the slogan ‘Nature does nothing in vain’, and he himself frequently uses similar aphorisms. ‘Nature does nothing in vain’ is a regulative principle for scientific enquiry. ‘Teleology’ asserts that, even though Aristotle knew that some aspects of nature are functionless, he recognized that a grasp of function is crucial to understanding nature. References to the prudence of nature are not childish superstition, but reminders of a central task of the natural scientist.
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Oberauer, Klaus. "Towards a Theory of Working Memory." In Working Memory, 116–49. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780198842286.003.0005.
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Working memory provides a medium for building and manipulating new representations that control our thoughts and actions. To fulfil this function, a working memory system needs to meet six requirements: (1) it must have a mechanism for rapidly forming temporary bindings to combine elements into new structures; (2) it needs a focus of attention for selectively accessing individual elements for processing; (3) it must hold both declarative representations of what is the case, and procedural representations of how to act on the current situation; (4) it needs a process for rapid updating, including rapid removal of outdated contents. Moreover, contents of working memory (5) need to be shielded from interference from long-term memory, while (6) working memory should be able to use information in long-term memory when it is useful. This chapter summarizes evidence in support of these mechanisms and processes. It presents three computational models that each implement some of these mechanisms, and explains different subsets of empirical findings about working memory: the SOB-CS model accounts for behaviour in tests of immediate serial recall, including complex-span tasks. The interference model explains data from a common test of visual working memory, the continuous-reproduction task. The set-selection model explains how people learn memory sets and task sets, how these sets are retrieved from long-term memory, and how these mechanisms enable switching between memory sets and task sets.
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Ptak, Radek, and Armin Schnider. "Neuropsychological rehabilitation of higher cortical functions after brain damage." In Oxford Textbook of Neurorehabilitation, edited by Volker Dietz, Nick S. Ward, and Christopher Kennard, 291–304. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780198824954.003.0022.
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Neuropsychological interventions for impairments of higher cognitive functions can be divided into four different approaches: restoration of function, compensation, physiological stimulations, and metacognitive strategies. Training that aims to restore an impaired function or to increase processing speed or capacity is repetitive and often stereotyped. Such training may lead to task-specific learning with little generalization, as may be observed in particular in the domain of attention rehabilitation. However, it remains a matter of debate whether such practice effects really reflect the restoration of function or improved processing due to preserved procedural learning skills. For some cognitive domains (such as memory), restoration of function is mostly impossible; consequently, training mainly relies on compensatory strategies. For example, enhancement of learning may be achieved by improving memory encoding with mental imagery, while everyday memory is supported with systematic training of external aids, such as, memory notebooks. A third approach is applied in neglect rehabilitation and uses physiological stimulations to bias attention and sensory representations (e.g. optokinetic stimulation) or decrease interhemispheric inhibition (transcranial magnetic stimulation). Finally, the fourth approach is to structure behaviour and to enhance metacognitive abilities; this strategy is applied in the rehabilitation of complex problem-solving skills and impaired emotional regulation. Although it is difficult to control experimental biases in intervention studies targeting cognitive and behavioural disturbances, an increasing number of controlled clinical trials provide evidence for the efficacy of each of the four therapeutic approaches.
Conference papers on the topic "Function-task-behaviour"
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Beretta, A., V. Marchis, and R. Sinatra. "Robot Task Oriented Dexterity and Dynamic Performance: A Statistical Approach." In ASME 1991 Design Technical Conferences. American Society of Mechanical Engineers, 1991. http://dx.doi.org/10.1115/detc1991-0219.
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Abstract Robot task oriented dexterity has recently reached a well-known acknowledgment for its capability of definig robot arm manipulability figures, over the working space. Because it seemed to the authors that not yet robot dynamic performances have been taken into account in defining its local properties, it has been studied a simple 2R robot arm, in order to identify the most siutable parameters for this scope. By simulating a mathematical model forced with random input signals (forces), its dynamic behaviour has been investigated with a Monte Carlo approach. Without willing to obtain a complete modal analysis, some numerical parameters have been found as capable to identify system dynamics, e.g. the principal direction of system free oscillations, and its eigenfrequency value. Discussion of the results over the workspace and as a function of system mechanical stiffness properties is also performed.
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Brinkschulte, Lars, and Marcus Geimer. "Intelligent Machine Operator Identification to Develop Damage-Reducing Operating Strategies for Mobile Machines." In ASME/BATH 2019 Symposium on Fluid Power and Motion Control. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/fpmc2019-1643.
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Abstract Mobile machines are exposed to a multitude of influencing factors, such as the working task, the operator and the environmental conditions. This leads to a broad spectrum of load collectives for the machine components. In many cases it is difficult to influence the working task and the environmental conditions under the objective function of achieving the required work goals optimally while at the same time minimizing the component load. The operation of the machine offers a more evident degree of freedom to minimize the component damage. With control systems adapted to the operator, the external environmental conditions and the working task, which instructs the operator to a less damaging operating behaviour or override the damage-initiating control signals, the loads and damage can be reduced. An explicit operator identification is the basis for such control approaches. This paper presents a method for machine operator identification (MOI) based on Hidden Markov Models (HMM). Through a parameter influence analysis and a combination with operation state recognition (OSR), a machine operator can be successfully identified among others. To create and validate the method, measurement data from 150 work cycles of seven different operators are analysed. Based on the MOI, a method for an operator-specific damage reduction using adaptive control strategies is developed. The results and limits of this strategy are presented and discussed by means of a complete machine simulation, considering the traction drive and function drives (working hydraulics), a multi-body simulation and the driving dynamics. The conclusion is made by considering predictive operating strategies to avoid damage-intensive operating points.
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Wilkin, Tim, Yakov Frayman, and Bernard Rolfe. "Adaptive Control of the Closed Loop Behaviour of Manufacturing Processes." In ASME 8th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2006. http://dx.doi.org/10.1115/esda2006-95444.
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An open problem in manufacturing control is the design of controllers with guaranteed closed loop performance on plants subject to unmeasurable disturbances and changing dynamics. Existing methods for Adaptive Control of these plants typically rely on system identification techniques, which lead to a multi-objective optimisation task that offers no explicit guarantee regarding the stability of the closed loop system or the quality of its output. Robust Control design guarantees stability in the presence of unmeasured disturbances, although at the expense of sub-optimal control performance. We propose a control architecture and methodology for online adaptation of the process behavior that does not require explicit identification of the plant or disturbance dynamics. An arbitrary function approximator is used for control of the plant and the closed loop behaviour of this coupled system is adapted to that of a generic performance target. No exogenous signal is required for excitation of the adaptation, which instead used the inherent variability in the plant output. The use of a closed loop performance target for adaptation is practical, simple to implement and does not require a knowledge of either the plant dynamics or the disturbances acting on the process, since the controller is only concerned with maintaining transient process behavior within acceptable bounds. The resulting controller is capable of achieving a specified closed loop performance in the presence of unmeasurable, bounded disturbances, making the proposed scheme a viable candidate for disturbance rejection tasks.
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Henson, Brian W., Neal P. Juster, and Alan de Pennington. "Towards a Product Model for Virtual Prototyping." In ASME 1995 15th International Computers in Engineering Conference and the ASME 1995 9th Annual Engineering Database Symposium collocated with the ASME 1995 Design Engineering Technical Conferences. American Society of Mechanical Engineers, 1995. http://dx.doi.org/10.1115/cie1995-0823.
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Abstract Most virtual prototypes used within the domain of mechanical engineering are well defined geometric representations loosely linked to analysis packages. By taking a holistic, top-down view of the product introduction process this paper argues that virtual prototypes should be based upon product models that allow for the representation of more than just geometric information. A methodology based upon the reference model for open distributed processing is presented that simplifies the task of deciding what information should be supported. The paper argues that virtual prototypes should use product models that integrate the representation of the geometry, function and behaviour of a product. A case study is presented to show how experimental virtual prototyping software, based on such a product model, can aid the product introduction process.
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Lotfi, O., J. A. Teixeira, P. C. Ivey, G. Sheard, and I. R. Kinghorn. "Aerodynamic Optimization of Industrial Fan Blade Cascades." In ASME Turbo Expo 2005: Power for Land, Sea, and Air. ASMEDC, 2005. http://dx.doi.org/10.1115/gt2005-68385.
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The paper describes the application of a Genetic Algorithm (GA) to the aerodynamic shape optimization of a low speed fan cascade. This task is accomplished by modifying the blade camber line while keeping the same blade thickness distribution and mass flow rate. A number of design examples have been studied and the behaviour of the genetic algorithm has been tested. The fitness value of the objective function is evaluated using the commercial turbomachinery CFD code CFX-TASCflow. In this work Bezier curves were used for the description of the blade camber line. Specific interfaces were developed in order to link the optimization code, the grid generator TASCgrid utilized to define the computational meshes and the commercial flow solver TASCflow employed within an automated design loop. The obtained results show that the genetic algorithm is capable of automatically improving the design of axial fan blade profiles.
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Russo, Davide, Tiziano Montecchi, and Ying Liu. "Functional-Based Search for Patent Technology Transfer." In ASME 2012 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/detc2012-70833.
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Patent literature contains over 70 million patent documents, so the amount of information available to companies and the opportunity to derive business value and market new products from this collection is huge. However, presently an effective information extraction is a difficult task because patentees typically write using their own lexicon, style and strategy in describing their inventions. This paper presents a discussion about open problems and a way to overcome them by a new functional search based on Function-Behaviour-Physical effect-Structure ontology. This ontology is used for a technology transfer activity by patents, with the aim of making users aware of how technologies, not yet exploited in their own field, have already been patented in other domains and exactly for achieving their same desired goal. To reach this objective a multidisciplinary approach is proposed, combining design ontologies with information retrieval tools. A case study has been presented to demonstrate how the conceived framework is strategic to search for patents and automatically classify them according to the proposed ontology.
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Oliveira, Ricardo F., Nelson Rodrigues, José Carlos Teixeira, Duarte Santos, Delfim Soares, Maria F. Cerqueira, and Senhorinha F. C. F. Teixeira. "A Numerical Study of Solder Paste Rolling Process for PCB Printing." In ASME 2018 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/imece2018-88035.
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The increasing demand for electronic devices associated with the increasing competitiveness between enterprises, pushes towards process automation to decrease production costs. The reflow soldering has proven to be effective in this regard. This is composed by a series of steps or processes, such as: (a) stencil printing, (b) component placement and (c) reflow oven soldering. Each process has its specific traits that contribute to the overall process efficiency. The present study is directed towards process (a), which includes the rolling of the solder paste over the stencil surface, followed by the subsequent filling of the stencil apertures. Several parameters influence the solder paste behaviour and thus the effectiveness of the rolling process. This work focuses on the solder paste non-Newtonian viscosity properties, with the solder paste presenting a thixotropic behaviour, necessary for the filling of the stencil apertures. Although the increase in the squeegee velocity causes extra shear in the solder paste and consequently lower viscosity, the excess of velocity may cause defects in the aperture filling process. In addition, during the rolling process, air may become entrapped in the solder paste. The complexity of this process is addressed by numerical simulation, in particular, using the work-package ANSYS to study the solder paste progress, during the rolling process, as well as the parameters influencing it. The fluid flow simulation is solved using the solver FLUENT®, a simplified 2D domain with real case dimensions, a transient prediction of the viscosity, which is a function of the solder paste solicitation, and finally by using the Volume of Fluid (VOF) method to track the solder-air interface boundary. Dynamic meshing methods are also employed to replicate the movement of the squeegee wall, in its task to push the solder paste tumble over the stencil. This study enlightens the role played by the printing velocity in the stencil aperture filling, a logarithm correlation can be found between them. It was found that lower print velocities provide better results than higher speeds. It was observed that the back tip of the squeegee blade causes a partial removal of the solder paste from the aperture, which is higher for faster print processes. An analysis of the filling process over time concluded that, independently of the printing velocity, 90% of the filling occurs in the first quarter of the process.
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Rajhi, Ramzi, Lakhdar Taleb, and Abdelkhalak Elhami. "Cyclic Thermoelastoplasticity Structural Calculation: Reliability and Sensitivity of Material Parameters." In ASME 2005 Pressure Vessels and Piping Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/pvp2005-71477.
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The essential cause of the ruptures of the structures under loadings is related most of times to the cyclical component of thermo-mechanical loadings. Forecasting the state of the structures is a very important task but simulating the structures behavior depends on a large data set of various parameters. In general, these parameters could be related to the geometry, loads and material characteristics or behavior law of the used phenomenological models. They are always known with a certain margin of incertitude that might have several origins such the experimental disparity in the material behavior or dependence on some physical variables like temperature. It is essential to measure degrees of influence of these parameters, thus the need for having analysis tools allowing the evaluation of the effects of parameters uncertainty on the structures behaviour. In this work, we study at first the reliability of the structural analyses making use of the Linear Kinematic Model of behavior in cyclic thermoelastoplasticity. Reliability will be applied to a first axis-symmetric structure. Then we propose a method based on the techniques of disturbances in order to determine the sensitivities of the phenomenological models with respect to the material parameters. This method will be applied through its two proposed approaches to a second structure. We made several assumptions. Deterministic calculations made it possible to validate the assuptions which relate to the choice of the absolute limit function. They also made it possible to confirm our expectations about the performance of the software package used (localization and values of the maximum plastic deformations). The assumption on the random variables laws are justified by the fact that the major part of the values taken are condensed around the mean value and that it is probably to exceed it as much than not to exceed it (normal law). The assumption on the value of the standard deviation holds all its validity owing to the fact that truncations must remain in conformity at the same time with the concept of density and physical limits of the variables. “The equations of dependences” make it possible to keep a sense which respects the relations of order that connects the random variables of the same nature as well reducing the cost of calculations.
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Fiorentino, Maria, and Giuseppe Starace. "A Numerical Model to Investigate Evaporative Condensers Behaviour at Tube Scale." In ASME 2014 12th Biennial Conference on Engineering Systems Design and Analysis. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/esda2014-20483.
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Evaporative condensers operate at lower temperatures and with a higher efficiency compared to air condensers, as heat rejection is limited by air wet bulb temperature and mainly caused by water vaporization. This reduces the compressor pressure-lift and improves refrigeration cycle performance. Due to complex phenomena of heat and mass transfer on the tube bundles, modeling the evaporative condensers is a hard task and fine grids in numerical simulations are requested to reach acceptable results. A two-dimensional steady state numerical model at the single tube scale has been developed in Ansys-Fluent (release- 14.5), adopting the VOF multiphase model. Moist air has been treated as a mixture of air and water vapor species, while water vaporization and latent heat have been modeled with a C++ User Defined Function. The tube wall temperature has been assumed constant. The aim of this work is to describe the developed numerical model and to validate it by comparing results obtained at different operating conditions with empirical relationships found in the literature in terms of combined and overall heat transfer coefficients. Combined heat transfer coefficient variation along the tube surface has been analyzed, observing that the heat transfer coefficient is higher in the impingement zone, becomes approximately uniform and rises approaching the trailing edge. Moisture content distributions at different sections through the heat exchanger have been examined in detail as well. This study will be the basis to investigate the performance of the whole condenser taking into account the real evolution of the operating conditions of each single tube in the bundle, whatever its arrangement.