Development of competitive high-entropy alloys using commodity powders

One of the main drawbacks of the powder metallurgy route for High-Entropy Alloys (HEAs) is the unavailability of fully pre-alloyed powders in the market. Using commodity powders (commercial Ni, Fe and Co base fully pre-alloyed powders, fully available in large quantities and at competitive prices) to produce HEAs presents a completely new and competitive scenario for obtaining viable alloys for high-performance applications

Labour productivity in mixed-model manual assembly 4.0

Manual assembly lines productivity is threatened by the increased complexity brought by mass customisation demand trends. Industry 4.0 offers potential solutions to address this situation, but the methodology to implement it is still a subject of study. As a preliminary step, this article aims to identify the dominant factors affecting the Key Performance Indicators of mixed-model assembly lines. To do so, parametric and discrete-events simulation models were developed, and Design of Experiments techniques were used. The results show that the key drivers for assembly line performance are number of work stations and batch size, and that increasing the work content ratio of the products assembled does not interact negatively with other factors. The results presented here pave the way for developing Industry 4.0 projects that address specifically the most relevant factors that affect assembly lines performance

Lean manual assembly 4.0: A systematic review

In a demand context of mass customization, shifting towards the mass personalization of products, assembly operations face the trade-off between highly productive automated systems and flexible manual operators. Novel digital technologies—conceptualized as Industry 4.0—suggest the possibility of simultaneously achieving superior productivity and flexibility. This article aims to address how Industry 4.0 technologies could improve the productivity, flexibility and quality of assembly operations. A systematic literature review was carried out, including 234 peer-reviewed articles from 2010–2020. As a result, the analysis was structured addressing four sets of research questions regarding (1) assembly for mass customization; (2) Industry 4.0 and performance evaluation; (3) Lean production as a starting point for smart factories, and (4) the implications of Industry 4.0 for people in assembly operations. It was found that mass customization brings great complexity that needs to be addressed at different levels from a holistic point of view; that Industry 4.0 offers powerful tools to achieve superior productivity and flexibility in assembly; that Lean is a great starting point for implementing such changes; and that people need to be considered central to Assembly 4.0. Developing methodologies for implementing Industry 4.0 to achieve specific business goals remains an open research topic

Operator-centred Lean 4.0 framework for flexible assembly lines

This article provides a starting point for developing a methodology to successfully implement Industry 4.0 technology for assembly operations. It presents a novel multi-layer human-centred conceptual model in line with Lean philosophy which identifies the assembly operator functions and relates them to other production departments, identifying how they would be affected by incorporating new digital technologies. The model shows that assembly operators would only be directly supported by hardware digital technologies, while the production support departments would mainly employ Industry 4.0 software technologies. The work presented here paves the way for developing a methodology for implementing Lean Assembly 4.0

What are the shapes of response time distributions in visual search?

Many visual search experiments measure response time (RT) as their primary dependent variable. Analyses typically focus on mean (or median) RT. However, given enough data, the RT distribution can be a rich source of information. For this paper, we collected about 500 trials per cell per observer for both target-present and target-absent displays in each of three classic search tasks: feature search, with the target defined by color; conjunction search, with the target defined by both color and orientation; and spatial configuration search for a 2 among distractor 5s. This large data set allows us to characterize the RT distributions in detail. We present the raw RT distributions and fit several psychologically motivated functions (ex-Gaussian, ex-Wald, Gamma, and Weibull) to the data. We analyze and interpret parameter trends from these four functions within the context of theories of visual search

Efficient On-the-fly Category Retrieval using ConvNets and GPUs

We investigate the gains in precision and speed, that can be obtained by using Convolutional Networks (ConvNets) for on-the-fly retrieval - where classifiers are learnt at run time for a textual query from downloaded images, and used to rank large image or video datasets. We make three contributions: (i) we present an evaluation of state-of-the-art image representations for object category retrieval over standard benchmark datasets containing 1M+ images; (ii) we show that ConvNets can be used to obtain features which are incredibly performant, and yet much lower dimensional than previous state-of-the-art image representations, and that their dimensionality can be reduced further without loss in performance by compression using product quantization or binarization. Consequently, features with the state-of-the-art performance on large-scale datasets of millions of images can fit in the memory of even a commodity GPU card; (iii) we show that an SVM classifier can be learnt within a ConvNet framework on a GPU in parallel with downloading the new training images, allowing for a continuous refinement of the model as more images become available, and simultaneous training and ranking. The outcome is an on-the-fly system that significantly outperforms its predecessors in terms of: precision of retrieval, memory requirements, and speed, facilitating accurate on-the-fly learning and ranking in under a second on a single GPU.Comment: Published in proceedings of ACCV 201

The grumpy bin:reducing food waste through playful social interactions

Domestic food waste is a world-wide problem that is complex and difficult to tackle as it touches diverse habits and social behaviors. This paper introduces the Grumpy Bin, a smart food waste bin designed for the context of student housing. The Grumpy Bin1 contributes to the state of the art of food waste prevention solutions by challenging the traditional approach on pervasive technology, which is commonly based on system-driven judgements and persuasive data representations. Instead, this design empowers users and their social acquaintances to collectively judge their actions, hence adding a layer of social mediation that is likely to increase the chance for behavior change.</p

Assessment of motor coordination in primary education of Barcelona and province

El presente estudio tiene por objetivo valorar la coordinación motora de estudiantes de primaria de Barcelona y provincia. Para la evaluación se ha utilizado el test KTK en el que participaron 1254 personas, 670 niños y 584 niñas, de edades entre 7 y 10 años. Se realizó el análisis descriptivo y la comparación entre género y edad. Los resultados indican que más del 40% de la población estudiada presenta una coordinación por debajo de la normalidad, cerca de un 57% de la muestra fue clasificado con coordinación normal y solamente el 4,6% lo ha sido por encima de esta clasificación. Los chicos han presentado resultados significativamente mejores que las chicas. Los datos del estudio no permiten generalizar los resultados, sin embargo como es una muestra representativa, nos lleva a creer que la población de alumnos en educación primaria de Barcelona y su provincia tiene un nivel coordinativo por debajo del esperado para su edadThe present study aims to assess motor coordination of primary-school students of Barcelona and its province. For evaluation we used the KTK test. 1254 people, 670 boys and 584 girls with ages between 7 and 10 years participated in the study. Descriptive analysis and the comparison between gender and age were performed. The results indicate that about 40% of the population studied presents results below normal, around 57% were classified with normal coordination and only 4.6% has been above this rating. The boys have presented significantly better results than girls. The study data do not permit to generalize the results, however as a representative sample, it leads us to believe that the student population in elementary education from Barcelona and its province has a coordinative level below expected for their ageAgrupació de Recerca en Ciències de l’Educació. U

Analysis of surface extraction methods based on gradient operators for computed tomography in metrology applications

Among the multiple factors influencing the accuracy of Computed Tomography measurements, the surface extraction process is a significant contributor. The location of the surface for metrological applications is generally based on the definition of a gray value as a characteristic of similarity to define the regions of interest. A different approach is to perform the detection or location of the surface based on the discontinuity or gradient. In this paper, an adapted 3D Deriche algorithm based on gradient information is presented and compared with a previously developed adapted Canny algorithm for different surface types. Both algorithms have been applied to nine calibrated workpieces with different geometries and materials. Both the systematic error and measurement uncertainty have been determined. The results show a significant reduction of the deviations obtained with the Deriche-based algorithm in the dimensions defined by flat surfaces