167 research outputs found
Augmented and Virtual Reality techniques for footwear
The use of 3D imaging techniques has been early adopted in the footwear industry. In particular, 3D imaging could be used to aid commerce and improve the quality and sales of shoes. Footwear customization is an added value aimed not only to improve product quality, but also consumer comfort. Moreover, customisation implies a new business model that avoids the competition of mass production coming from new manufacturers settled mainly in Asian countries. However, footwear customisation implies a significant effort at different levels. In manufacturing, rapid and virtual prototyping is required; indeed the prototype is intended to become the final product. The whole design procedure must be validated using exclusively virtual techniques to ensure the feasibility of this process, since physical prototypes should be avoided. With regard to commerce, it would be desirable for the consumer to choose any model of shoes from a large 3D database and be able to try them on looking at a magic mirror. This would probably reduce costs and increase sales, since shops would not require storing every shoe model and the process of trying several models on would be easier and faster for the consumer. In this paper, new advances in 3D techniques coming from experience in cinema, TV and games are successfully applied to footwear. Firstly, the characteristics of a high-quality stereoscopic vision system for footwear are presented. Secondly, a system for the interaction with virtual footwear models based on 3D gloves is detailed. Finally, an augmented reality system (magic mirror) is presented, which is implemented with low-cost computational elements that allow a hypothetical customer to check in real time the goodness of a given virtual footwear model from an aesthetical point of view
Efeitos da Pandemia COVID-19 no Risco de Desenvolvimento de Psicopatologia das Crianças em Portugal: Um Estudo com Dados Seccionais
Introduction: This study is based on preliminary data from a 2021 survey of parents of children aged 3-13 years atthe time of SARS-CoV-2 infection. The aim is to understand the consequences of SARS-CoV-2 infection on children\u27s mental health.
Methods: Using the Strengths and Difficulties Questionnaire (SDQ) and survey data, we specified multiple linear regression models to explain the variation in the total SDQ and the variation in its five components â emotional symptoms, conduct problems, hyperactivity, peer relationship problems, and prosocial behaviour. We used explanatory variables selected according to current literature and other empirical studies, such as age, gender, household changes, confinement, hospitalization time, previous mental health care and longâCOVID symptoms (headache, sleep problems, concentration problems, fatigue).
Results: The results showed that age was not statistically significant in any of the estimated models. The gender variable proved to be significant in three models (total SDQ, conduct problems, hyperactivity) and the results show that girls have fewer problems when compared to boys.Conclusion: Results suggest that intensive care hospitalisation and long-COVID symptoms increase the risk of psychopathology.IntroduçaÌo: Este estudo baseia-se nos dados preliminares de um inqueÌrito feito no ano 2021 aos pais de crianças com idades compreendidas entre os 3 e os 13 anos aÌ data da infeçaÌo por SARS-CoV-2. O objetivo eÌ compreender os efeitos da infeçaÌo por SARS-CoV-2 na sauÌde mental das crianças.
MeÌtodos: Utilizando o QuestionaÌrio de Capacidades e Dificuldades e os dados do inqueÌrito, especificaÌmos modelosde regressaÌo linear muÌltipla para explicar a variaçaÌo do SDQ total e a variaçaÌo das suas cinco componentes - sintomas emocionais, problemas de comportamento, hiperatividade, problemas de relacionamento, comportamento proÌ-social. Foram utilizadas variaÌveis explicativas consideradas relevantes pela teoria e por outros estudos empiÌricos, tais como: idade, geÌnero, alteraçaÌo familiar, confinamento, tempo de internamento, seguimento de sauÌde mental preÌvio e sintomas long-COVID (cefaleias, problemas do sono, da concentraçaÌo, fadiga).
Resultados: Os resultados evidenciaram que a idade naÌo se revelou estatisticamente significativa em nenhumdos modelos estimados. A variaÌvel geÌnero revelouâse significativa em treÌs modelos (SDQ total, problemas do comportamento, hiperatividade) e os resultados evidenciam que raparigas teÌm menos problemas quando comparadas com os rapazes.
ConclusaÌo: Os resultados sugerem que o internamento em cuidados intensivos e os sintomas long-COVID aumentam o risco de psicopatologi
Decentralized ellipsoidal state estimation for linear model predictive control of an irrigation canal
A centralized linear MPC is used to stabilize an irrigation system whose operation is represented by an integrator-delay model. Since not all the state variables can be measured, a decentralized ellipsoidal estimation strategy is proposed. This approach keeps the quality of a centralized estimation and reduces significantly the computation time for the systems considered. An adaptation of Test Canal 1, developed by the ASCE Task Committee on Canal Automation Algorithms, is used as a case study to show the performance of the proposed methodology.Fil: Rodriguez Aguilar, Leandro Pedro Faustino. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - San Juan; ArgentinaFil: Maestre, J. M.. Universidad de Sevilla. Escuela TĂ©cnica Superior de IngenierĂa; EspañaFil: Camacho, E. F.. Universidad de Sevilla. Escuela TĂ©cnica Superior de IngenierĂa; EspañaFil: Sanchez, Mabel Cristina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - BahĂa Blanca. Planta Piloto de IngenierĂa QuĂmica. Universidad Nacional del Sur. Planta Piloto de IngenierĂa QuĂmica; Argentin
Control Based on Linear Algebra for Trajectory Tracking and Positioning of Second-Order Chained Form System
The development of controllers for underactuated systems with nonholonomic constraints has been a topic of significant interest for many researchers in recent years. These systems are hard to control because their linearization transform them into uncontrollable systems. The proposed approaches involve the use of a permanent excitation in the reference trajectory; coordinate transformation; discontinuities; or complex calculations. This paper proposes the design of the controller of the second-order chained form system for trajectory tracking by using a simpler approach based on linear algebra. Up to the present time, no controllers based on this approach have been designed for that system. The control problem is solved by setting two of the three systems variables as a reference, while the remaining variable is calculated imposing the condition that the equations system has an exact solution to ensure that tracking errors go to zero. The stability of the proposed controller is theoretically demonstrated, and simulations results show a suitable control system performance. Also, no coordinate transformation is necessary.Fil: Rodriguez Aguilar, Leandro Pedro Faustino. Universidad Nacional de San Juan. Facultad de IngenierĂa. Instituto de IngenierĂa QuĂmica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - San Juan; ArgentinaFil: Serrano, Mario Emanuel. Universidad Nacional de San Juan. Facultad de IngenierĂa. Instituto de IngenierĂa QuĂmica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - San Juan; ArgentinaFil: Sanchez, Mabel Cristina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - BahĂa Blanca. Planta Piloto de IngenierĂa QuĂmica. Universidad Nacional del Sur. Planta Piloto de IngenierĂa QuĂmica; ArgentinaFil: Scaglia, Gustavo Juan Eduardo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de IngenierĂa. Instituto de IngenierĂa QuĂmica; Argentin
Automation of the shoe last grading process according to international sizing systems
The last is the basic industrial component in footwear manufacturing, from which product development starts. Correct last grading ensures the best fit for the intended group of users of the footwear model to be produced. The size marked on the last should respect the specific intervals defined in the different international sizing systems, like the European, UK, US or Mondopoint systems, which are all described in international standards. New approaches in the field of CAD/CAM have emerged over recent years towards the automation of this process. However, these are partial approaches that neither address the grading process according to the different standards nor consider the various parts of the shoe that are not affected by size increments. This paper presents a new accurate and efficient technique for the automation of the shoe last grading process based on the conjugate gradient method. Through this method, it is possible to obtain a graded shoe last that conforms to the international standards in force relative to shoe sizing and allows for the shoe parts that are not affected by size increments. This technique is based on the target measures of length and perimeter of the last to be graded and aims to minimise the quadratic difference between these values and those obtained from the graded last. This method has been evaluated through a battery of tests performed on a geometrically heterogeneous group of shoe lasts. The results obtained were accurate and the execution time was fast enough to be used for mass production
The usefulness of mesocosms for ecotoxicity testing with lacertid lizards
Mesocosms (i.e., outdoor, man-made representations of natural ecosystems) have seldom been used to study the impact of contaminants on terrestrial ecosystems. However, mesocosms can be a useful tool to provide a link between field and laboratory studies. We exposed juvenile lacertid lizards for a period of over one year to pesticides (herbicides and insecticides) in mesocosm enclosures with the intention of validating field observations obtained in a previous study that examined the effects of corn pesticides in Podarcis bocagei. Our treatments replicated field conditions and consisted of a control, an herbicides only treatment (alachlor, terbuthylazine, mesotrione and glyphosate) and an herbicides and insecticide treatment (including chlorpyrifos). We used a multi-biomarker approach that examined parameters at an individual and sub-individual level, including growth, locomotor performance, standard metabolic rate, biomarkers of oxidative stress, esterases and liver histopathologies. Although mortality over the course of the exposures was high (over 60%), surviving individuals prospered relatively well in the mesocosms and displayed a broad range of natural behaviours. The low numbers of replicate animals compromised many of the statistical comparisons, but in general, surviving lizards exposed to pesticides in mesocosm enclosures for over one year, thrived, and displayed few effects of pesticide exposure. Despite the difficulties, this work acts as an important stepping-stone for future ecotoxicology studies using lizards.publishe
A strategy for scaling up access to comprehensive care in adults with Chagas disease in endemic countries: The Bolivian Chagas Platform
BACKGROUND: Bolivia has the highest prevalence of Chagas disease
(CD) in the world (6.1%), with more than 607,186 people with
Trypanosoma cruzi infection, most of them adults. In Bolivia CD
has been declared a national priority. In 2009, the Chagas
National Program (ChNP) had neither a protocol nor a clear
directive for diagnosis and treatment of adults. Although
programs had been implemented for congenital transmission and
for acute cases, adults remained uncovered. Moreover, health
professionals were not aware of treatment recommendations aimed
at this population, and research on CD was limited; it was
difficult to increase awareness of the disease, understand the
challenges it presented, and adapt strategies to cope with it.
Simultaneously, migratory flows that led Bolivian patients with
CD to Spain and other European countries forced medical staff to
look for solutions to an emerging problem. INTERVENTION: In this
context, thanks to a Spanish international cooperation
collaboration, the Bolivian platform for the comprehensive care
of adults with CD was created in 2009. Based on the
establishment of a vertical care system under the umbrella of
ChNP general guidelines, six centres specialized in CD
management were established in different epidemiological
contexts. A common database, standardized clinical forms, a and
a protocolized attention to adults patients, together with
training activities for health professionals were essential for
the model success. With the collaboration and knowledge transfer
activities between endemic and non-endemic countries, the
platform aims to provide care, train health professionals, and
create the basis for a future expansion to the National Health
System of a proven model of care for adults with CD. RESULTS:
From 2010 to 2015, a total of 26,227 patients were attended by
the Platform, 69% (18,316) were diagnosed with T. cruzi, 8,567
initiated anti-parasitic treatment, more than 1,616 health
professionals were trained, and more than ten research projects
developed. The project helped to increase the number of adults
with CD diagnosed and treated, produce evidence-based clinical
practice guidelines, and bring about changes in policy that will
increase access to comprehensive care among adults with CD. The
ChNP is now studying the Platform's health care model to adapt
and implement it nationwide. CONCLUSIONS: This strategy provides
a solution to unmet demands in the care of patients with CD,
improving access to diagnosis and treatment. Further scaling up
of diagnosis and treatment will be based on the expansion of the
model of care to the NHS structures. Its sustainability will be
ensured as it will build on existing local resources in Bolivia.
Still human trained resources are scarce and the high staff
turnover in Bolivia is a limitation of the model. Nevertheless,
in a preliminary two-years-experience of scaling up this model,
this limitations have been locally solved together with the
health local authorities
Linear Algebra Based Control: Application to a Second Order Chained FormSystem
Control of underactuated systems with non-holonomic constraints has been an issue of interest in recent years. These systems are hard to control because their linearization makes them uncontrollable and current approaches generally involve complex calculations.In this manuscript,a controller for trajectory tracking and positioning for a second-order chained form system using a simple approach based on linear algebra is proposed.The control law is formulated by setting two of the six variables trajectories, while the other four are calculated assuming the equations system has an exact solution, and ensuring the error tendsto zero. The stability of the proposed control system is demonstrated through the KhalilLemma, and simulations show theperformance of the controller.Fil: Rodriguez Aguilar, Leandro Pedro Faustino. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de IngenierĂa. Instituto de IngenierĂa QuĂmica; ArgentinaFil: FernĂĄndez Puchol, MarĂa Cecilia. Universidad Nacional de San Juan. Facultad de IngenierĂa. Instituto de IngenierĂa QuĂmica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - San Juan; ArgentinaFil: Sanchez, Mabel Cristina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - BahĂa Blanca. Planta Piloto de IngenierĂa QuĂmica. Universidad Nacional del Sur. Planta Piloto de IngenierĂa QuĂmica; ArgentinaFil: Scaglia, Gustavo Juan Eduardo. Universidad Nacional de San Juan. Facultad de IngenierĂa. Instituto de IngenierĂa QuĂmica; Argentina. Universidad Nacional de San Juan. Facultad de IngenierĂa. Instituto de IngenierĂa QuĂmica; Argentin
Social and content hybrid image recommender system for mobile social networks
One of the advantages of social networks is the possibility to socialize and personalize the content created or shared by the users. In mobile social networks, where the devices have limited capabilities in terms of screen size and computing power, Multimedia Recommender Systems help to present the most relevant content to the users, depending on their tastes, relationships and profile. Previous recommender systems are not able to cope with the uncertainty of automated tagging and are knowledge domain dependant. In addition, the instantiation of a recommender in this domain should cope with problems arising from the collaborative filtering inherent nature (cold start, banana problem, large number of users to run, etc.). The solution presented in this paper addresses the abovementioned problems by proposing a hybrid image recommender system, which combines collaborative filtering (social techniques) with content-based techniques, leaving the user the liberty to give these processes a personal weight. It takes into account aesthetics and the formal characteristics of the images to overcome the problems of current techniques, improving the performance of existing systems to create a mobile social networks recommender with a high degree of adaptation to any kind of user
Derivation, validation, and clinical relevance of a pediatric sepsis phenotype with persistent hypoxemia, encephalopathy, and shock
OBJECTIVES: Untangling the heterogeneity of sepsis in children and identifying clinically relevant phenotypes could lead to the development of targeted therapies. Our aim was to analyze the organ dysfunction trajectories of children with sepsis-associated multiple organ dysfunction syndrome (MODS) to identify reproducible and clinically relevant sepsis phenotypes and determine if they are associated with heterogeneity of treatment effect (HTE) to common therapies.
DESIGN: Multicenter observational cohort study.
SETTING: Thirteen PICUs in the United States.
PATIENTS: Patients admitted with suspected infections to the PICU between 2012 and 2018.
INTERVENTIONS: None.
MEASUREMENTS AND MAIN RESULTS: We used subgraph-augmented nonnegative matrix factorization to identify candidate trajectory-based phenotypes based on the type, severity, and progression of organ dysfunction in the first 72 hours. We analyzed the candidate phenotypes to determine reproducibility as well as prognostic, therapeutic, and biological relevance. Overall, 38,732 children had suspected infection, of which 15,246 (39.4%) had sepsis-associated MODS with an in-hospital mortality of 10.1%. We identified an organ dysfunction trajectory-based phenotype (which we termed persistent hypoxemia, encephalopathy, and shock) that was highly reproducible, had features of systemic inflammation and coagulopathy, and was independently associated with higher mortality. In a propensity score-matched analysis, patients with persistent hypoxemia, encephalopathy, and shock phenotype appeared to have HTE and benefit from adjuvant therapy with hydrocortisone and albumin. When compared with other high-risk clinical syndromes, the persistent hypoxemia, encephalopathy, and shock phenotype only overlapped with 50%-60% of patients with septic shock, moderate-to-severe pediatric acute respiratory distress syndrome, or those in the top tier of organ dysfunction burden, suggesting that it represents a nonsynonymous clinical phenotype of sepsis-associated MODS.
CONCLUSIONS: We derived and validated the persistent hypoxemia, encephalopathy, and shock phenotype, which is highly reproducible, clinically relevant, and associated with HTE to common adjuvant therapies in children with sepsis
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