混凝土泵车浇筑过程机器人化探讨

对混凝土泵车布料机构的运动姿态调整采取了最优控制 ,解决了泵车机器人化的运动分析的臂解问题 ,论述了泵车动态分析中应解决和注意的问题 ,给出了泵车控制自动化的程序流程图和控制系统图 ,从而为提高泵车施工过程的自动化和泵车的机器人化提出了新的思路

Sobrecargas posturais

Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária

Inferring Body Pose without Tracking Body Parts

A novel approach for estimating articulated body posture and motion from monocular video sequences is proposed. Human pose is defined as the instantaneous two dimensional configuration (i.e., the projection onto the image plane) of a single articulated body in terms of the position of a predetermined set of joints. First, statistical segmentation of the human bodies from the background is performed and low-level visual features are found given the segmented body shape. The goal is to be able to map these, generally low level, visual features to body configurations. The system estimates different mappings, each one with a specific cluster in the visual feature space. Given a set of body motion sequences for training, unsupervised clustering is obtained via the Expectation Maximation algorithm. Then, for each of the clusters, a function is estimated to build the mapping between low-level features to 3D pose. Currently this mapping is modeled by a neural network. Given new visual features, a mapping from each cluster is performed to yield a set of possible poses. From this set, the system selects the most likely pose given the learned probability distribution and the visual feature similarity between hypothesis and input. Performance of the proposed approach is characterized using a new set of known body postures, showing promising results.

Estimating Human Body Pose from a Single Image via the Specialized Mappings Architecture

A non-linear supervised learning architecture, the Specialized Mapping Architecture (SMA) and its application to articulated body pose reconstruction from single monocular images is described. The architecture is formed by a number of specialized mapping functions, each of them with the purpose of mapping certain portions (connected or not) of the input space, and a feedback matching process. A probabilistic model for the architecture is described along with a mechanism for learning its parameters. The learning problem is approached using a maximum likelihood estimation framework; we present Expectation Maximization (EM) algorithms for two different instances of the likelihood probability. Performance is characterized by estimating human body postures from low level visual features, showing promising results.

(Un)veiling desire: re-defining relationships between gendered adult education subjects and adult education programmes

My underlying argument, in this paper, is that conceptualisations of power as a commodity, through which the 'disempowered-as-illiterate' subject moves towards becoming an 'empowered-as-literate' subject, forces constructs of identities into a powerful/powerless dichotomy which does not always do justice to diverse experiences. The claimed 'empowering' intentions of adult education programme and policy practice may, in reality, contribute to the dominance of restrictive disciplining and regulatory discursive practices. Moving away from emancipatory trajectories of adult education programmes that allege only liberation from domination, through 'literacy', can promise freedom points to another position of hope. Drawing on Foucauldian analysis, I explore sites of resistance as possibilities of transforming 'structures of understanding' at different levels. Officially validated and recognised transformations, in adult education programme as well as policy understandings, of the 'illiterate' subject may also hope to include choices in postures of autonomy (see Spivak 1996) made by programme participants in other 'fields' of socio-cultural practice linked to their material realities. Subsequently, 'empowerment' of the 'illiterate Indian village woman' cannot solely be imagined as a product of laws, policies and institutional discursive practices (see, for example, Gouws 2005; Rai 2003 on gender mainstreaming and Mosse 2005 on aid policy and practice). The 'illiterate Indian village woman' represented as a site of resistance, throughout this paper, displaces homogeneous representations of the 'illiterate' which situate her in the role of 'dependent' or 'victim', as failed attempts to rob her of her historical and political agency (Mohanty 1996). Through narrating other 'images' of refusal in my ethnographic vignettes, I hope to recognise different individuals' sense of agency, at all levels, as embedded in and evolving through forms of collective action that activate differences in order to develop possibilities and sustain hope for transforming historically rooted discursive practices of inequality. I provide ethnographic accounts of resisting 'literacy' programme participants, based in different villages in Bihar (Northern India), as accounts of resistance impacted on by notions of norms, translating and interpreting Others, networks and empowerment.

"Angels and Demons in Cromwellian and Restoration Ireland: Heresy and the Supernatural"

This essay explores accounts of supernatural activity in Cromwellian and Restoration Ireland. Religious life in Cromwellian Ireland was driven by expectations of the unusual—including audible voices from heaven, material encounters with angels, and spiritual encounters with demons. Some conservative Protestants linked this activity to the development and dissemination of heretical belief, while some who had such encounters were confident that it was compatible with the Cromwellian religious mainstream. Crawford Gribben explores the flexibility in the discourse of the marvelous in Ireland and the ways in which the administration contributed to it, and the alignment of the supernatural with various confessional convictions and postures, as well as theological radicalism. After the Restoration, accounts of supernatural encounters were remembered as ghost stories, not as matters for theological debate, a cultural transition linked to the development of a historiography that has continued to invest the Irish Cromwellian past with Gothic tropes.

Improving MTM-UAS to predetermine automotive maintenance times

The preventive knowledge of serviceability times is a critical factor for the quantification of after-sales services costs of a vehicle. Predetermined motion time system are frequently used to set labor rates in industry by quantifying the amount of time required to perform specific tasks. The first such system is known as Methods-time measurement (MTM). Several variants of MTM have been developed differing from each other on their level of focus. Among them MTM-UAS is suitable for processes that average around 1-3 min. However experimental tests carried out by the authors in Elasis (Research Center of FIAT Group) demonstrate that MTM-UAS is not the optimal approach to measure serviceability times. The reason is that it doesn't take into account ergonomic factors. In the present paper the authors propose to correct the MTM-UAS method including in the task analysis the study of human postures and efforts. The proposed approach allows to estimate with an "acceptable" error the time needed to perform maintenance tasks since the first phases of product design, by working on Digital Mock-up and human models in virtual environment. As a byproduct of that analysis, it is possible to obtain a list of maintenance times in order to preventively set after-sales service costs. © 2012 Springer-Verlag.

Episodic Reasoning for Vision-Based Human Action Recognition

Smart Spaces, Ambient Intelligence, and Ambient Assisted Living are environmental paradigms that strongly depend on their capability to recognize human actions. While most solutions rest on sensor value interpretations and video analysis applications, few have realized the importance of incorporating common-sense capabilities to support the recognition process. Unfortunately, human action recognition cannot be successfully accomplished by only analyzing body postures. On the contrary, this task should be supported by profound knowledge of human agency nature and its tight connection to the reasons and motivations that explain it. The combination of this knowledge and the knowledge about how the world works is essential for recognizing and understanding human actions without committing common-senseless mistakes. This work demonstrates the impact that episodic reasoning has in improving the accuracy of a computer vision system for human action recognition. This work also presents formalization, implementation, and evaluation details of the knowledge model that supports the episodic reasoning.

Risk assessment of patient handling with ambulance stretcher systems (ramp/(winch), easi-loader, tail-lift) using biomechanical failure criteria

The research aims to carry out a detailed analysis of the loads applied by the ambulance workers when loading/unloading ambulance stretchers. The forces required of the ambulance workers for each system are measured using a load cell in a force handle arrangement. The process of loading and unloading is video recorded for all the systems to register the posture of the ambulance workers in different stages of the process. The postures and forces exerted by the ambulance workers are analyzed using biomechanical assessment software to examine if the work loads at any stage of the process are harmful. Kinetic analysis of each stretcher loading system is performed. Comparison of the kinetic analysis and measurements shows very close agreement for most of the cases. The force analysis results are evaluated against derived failure criteria. The evaluation is extended to a biomechanical failure analysis of the ambulance worker's lower back using 3DSSPP software developed at the Centre for Ergonomics at the University of Michigan. The critical tasks of each ambulance worker during the loading and unloading operations for each system are identified. Design recommendations are made to reduce the forces exerted based on loading requirements from the kinetic analysis. © 2006 IPEM.

Laughter Type Recognition from Whole Body Motion

Despite the importance of laughter in social interactions it remains little studied in affective computing. Respiratory, auditory, and facial laughter signals have been investigated but laughter-related body movements have received almost no attention. The aim of this study is twofold: first an investigation into observers' perception of laughter states (hilarious, social, awkward, fake, and non-laughter) based on body movements alone, through their categorization of avatars animated with natural and acted motion capture data. Significant differences in torso and limb movements were found between animations perceived as containing laughter and those perceived as nonlaughter. Hilarious laughter also differed from social laughter in the amount of bending of the spine, the amount of shoulder rotation and the amount of hand movement. The body movement features indicative of laughter differed between sitting and standing avatar postures. Based on the positive findings in this perceptual study, the second aim is to investigate the possibility of automatically predicting the distributions of observer's ratings for the laughter states. The findings show that the automated laughter recognition rates approach human rating levels, with the Random Forest method yielding the best performance.

Cadaveric fascia lata pubovaginal slings:early results on safety, efficacy and patient satisfaction

Objective To prospectively evaluate and quantify the efficacy of cadaveric fascia lata (CFL) as an allograft material in pubovaginal sling placement to treat stress urinary incontinence (SUI).

Patients and methods Thirty-one women with SUI (25 type II and six type III; mean age 63 years, range 40-75) had a CFL pubovaginal sling placed transvaginally. The operative time, blood loss, surgical complications and mean hospital stay were all documented. Before and at 4 months and 1 year after surgery each patient completed a 3-day voiding diary and validated voiding questionnaires (functional inquiry into voiding habits, Urogenital Distress Inventory and Incontinence Impact Questionnaire, including visual analogue scales).

Results The mean (range) operative time was 71 (50-120) min, blood loss 78.7 (20-250) mL and hospital stay 1.2 (1-2) days; there were no surgical complications. Over the mean follow-up of 13.5 months, complete resolution of SUI was reported by 29 (93%) patients. Overactive bladder symptoms were present in 23 (74%) patients before surgery, 21 (68%) at 4 months and two (6%) at 1 year; 80% of patients with low (<15 cmH (2) O) voiding pressures before surgery required self-catheterization afterward, as did 36% at 4 months, but only one (3%) at 1 year. Twenty-four (77%) patients needed to adopt specific postures to facilitate voiding. After surgery there was a significant reduction in daytime frequency, leakage episodes and pad use (P <0.05). The severity of leak and storage symptoms was also significantly less (P <0.002), whilst the severity of obstructive symptoms remained unchanged. Mean subjective levels of improvement were 69% at 4 months and 85% at 1 year, with corresponding objective satisfaction levels of 61% and 69%, respectively. At 1 year, approximate to 80% of the patients said they would undergo the procedure again and/or recommend it to a friend.

Conclusion Placing a pubovaginal sling of CFL allograft is a highly effective, safe surgical approach for resolving SUI, with a short operative time and rapid recovery. Storage symptoms are significantly improved, and subjective improvement and satisfaction rates are high.

Perception and Automatic Recognition of Laughter from Whole-Body Motion: Continuous and Categorical Perspectives

Despite its importance in social interactions, laughter remains little studied in affective computing. Intelligent virtual agents are often blind to users’ laughter and unable to produce convincing laughter themselves. Respiratory, auditory, and facial laughter signals have been investigated but laughter-related body movements have received less attention. The aim of this study is threefold. First, to probe human laughter perception by analyzing patterns of categorisations of natural laughter animated on a minimal avatar. Results reveal that a low dimensional space can describe perception of laughter “types”. Second, to investigate observers’ perception of laughter (hilarious, social, awkward, fake, and non-laughter) based on animated avatars generated from natural and acted motion-capture data. Significant differences in torso and limb movements are found between animations perceived as laughter and those perceived as non-laughter. Hilarious laughter also differs from social laughter. Different body movement features were indicative of laughter in sitting and standing avatar postures. Third, to investigate automatic recognition of laughter to the same level of certainty as observers’ perceptions. Results show recognition rates of the Random Forest model approach human rating levels. Classification comparisons and feature importance analyses indicate an improvement in recognition of social laughter when localized features and nonlinear models are used.

Kinect and Episodic Reasoning for Human Action Recognition

This paper presents a method for rational behaviour recognition that combines vision-based pose estimation with knowledge modeling and reasoning. The proposed method consists of two stages. First, RGB-D images are used in the estimation of the body postures. Then, estimated actions are evaluated to verify that they make sense. This method requires rational behaviour to be exhibited. To comply with this requirement, this work proposes a rational RGB-D dataset with two types of sequences, some for training and some for testing. Preliminary results show the addition of knowledge modeling and reasoning leads to a significant increase of recognition accuracy when compared to a system based only on computer vision.

Contribuição parental do linguado do Senegal, Solea senegalensis (KAUP 1858), em aquacultura

Dissertação mest., Biologia Marinha, Universidade do Algarve, 2008

Les pratiques de différenciation d'enseignantes du primaire en classe multiethnique au Québec

Cette recherche a pour objectif principal d'analyser les pratiques de différenciation employées par des enseignants du primaire qui travaillent auprès de clientèles multiethniques. Appuyée sur un cadre de référence qui s'inspire des travaux de Payet, Sanchez-Mazas, Giuliani et Fernandez (2011) et de Prud'homme (2007) concernant les postures des acteurs scolaires face à la diversité, cette étude de cas multiples a analysé les postures et les pratiques différenciées de cinq enseignantes à partir de données provenant d'entrevues et d'observations en classe. Les résultats obtenus indiquent que, contrairement à la recherche et au discours officiel qui prônent une reconnaissance de la diversité ethnoculturelle comme une richesse à valoriser, les participantes de notre étude semblaient plutôt la considérer comme un déficit à combler et mettaient en place des interventions davantage individualisées que différenciées.Cette étude souligne donc la nécessité d'explorer le décalage entre le sens attribué à la différenciation pédagogique dans les écrits scientifiques et gouvernementaux et dans le milieu de pratique.