4,182 research outputs found
Raising awareness of smartphone overuse among university students: a persuasive systems approach
Smartphone overuse can lead to a series of physical, mental and social disturbances.
This problem is more prevalent among young adults as compared to other demographic groups.
Additionally, university students are already undergoing high cognitive loads and stress conditions;
therefore, they are more susceptible to smartphone addiction and its derived problems. In this
paper, we present a novel approach where a conversational mobile agent uses persuasive messages
exploring the reflective mind to raise users’ awareness of their usage and consequently induce
reduction behaviors. We conducted a four-week study with 16 university students undergoing
stressful conditions—a global lockdown during their semester—and evaluated the impact of the
agent on smartphone usage reduction and the perceived usefulness of such an approach. Results
show the efficacy of self-tracking in the behavior change process: 81% of the users reduced their
usage time, and all of them mentioned that having a conversational agent alerting them about their
usage was useful. Before this experiment, only 68% of them considered such an approach could be
useful. In conclusion, users deemed it essential to have an engaging conversational agent on their
smartphones, in terms of helping them become more aware of usage times.info:eu-repo/semantics/publishedVersio
A study of insulated glazing unit surface temperature profiles using two-dimensional computer simulation
© 1996. American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (www.ashrae.org). Published in ASHRAE Transactions, Vol. 102, Part 2. For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE’s prior written permission.This paper describes one part of a collaborative research project, including both measurement and simulation studies, aimed at determining the surface temperature of a set of insulated glazing units (IGUs). In this study computer simulation was used to determine the vertical surface temperature profiles of seven air-filled glazing units. Glazing system design options included variations in edge-seal type, pane spacing, low-e coating, and number of glazings. Two approaches were taken: one, a simulation of the complete problem domain using a fully detailed two-dimensional numerical simulation program (BRAVO); the second, a simplified approach using the VISION4 program for one-dimensional center-glass analysis and the FRAME 4.0 program for analysis of the remaining sections. This study serves as an important step in the development of alternative methods for evaluating condensation resistance. The present study significantly extends the database of two-dimensional simulation results. Details regarding the other parts of this project can also be found in the literature.CANMET (Natural Resources Canada || Natural Sciences and Engineering Research Council of Canad
Project management practices in private Portuguese organizations
Organizations are experiencing increasing pressure that is amplified by the current economic crises we are
facing, where innovation, cost reduction, resource optimization, quality and customer satisfaction are
increasingly even more important issues. Likewise, project management appears as a subject that has been
growing over the years helping organizations to meet their goals, through the implementation of their projects,
following good practices that are documented in various standards and methodologies. This research focuses
on such practices. The goal was to find which are the most used project management tools and techniques in
Portuguese Private Organizations and what factors influence their use
Project management practices in private organizations
This article aims to make a contribution to theory, as well as to practice, by identifying which project management practices are used by most private organizations in general and by sector of activity. The influence of practitioners' characteristics in the choice of project management practices and their use in groups are also analyzed. The results show that the most used project management practices are kick-off meetings, activity lists, progress meetings, Gantt charts, and baseline plans; however, differences between activity sectors and practitioners' characteristics were found. The results also indicate that the most used project management practices are, in fact, used as toolsets.The authors received financial support for the research, authorship, and/or publication of this article: This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT - Fundacao para a Ciencia e Tecnologia within the Project Scope: UID/CEC/00319/2013
Colon cancer chemoprevention by sage tea drinking: decreased DNA damage and cell proliferation
Salvia officinalis and some of its isolated compounds have been found to be preventive of DNA damage and increased proliferation in vitro in colon cells. In the present study, we used the azoxymethane model to test effects of S. officinalis on colon cancer prevention in vivo. The results showed that sage treatment reduced the number of ACF formed only if administered before azoxymethane injection, demonstrating that sage tea drinking has a chemopreventive effect on colorectal cancer. A decrease in the proliferation marker Ki67 and in H2O2-induced and azoxymethane-induced DNA damage to colonocytes and lymphocytes were found with sage treatment. This confirms in vivo the chemopreventive effects of S. officinalis. Taken together, our results show that sage treatment prevented initiation phases of colon carcinogenesis, an effect due, at least in part, to DNA protection, and reduced proliferation rates of colon epithelial cell that prevent mutations and their fixation through cell replication. These chemopreventive effects of S. officinalis on colon cancer add to the many health benefits attributed to sage and encourage its consumption.Fundação para a Ciência e a Tecnologia (FCT) - grant SFRH/BD/35672/2007, SFRH/BD/64817/200
Tool for applying mathematical morphology operators to grayscale images
Pasos previos a la medición y clasificación de rasgos y la posterior caracterización de imágenes, son el filtrado y la segmentación. Dada la utilidad de la morfología matemática en tales tareas, surgió la necesidad de incorporar una herramienta para la aplicación de operadores de morfología matemática sobre imágenes en escala de gris al prototipo Cimahis (Caracterización de imágenes histológicas), actualmente en desarrollo en la Universidad de Carabobo. La investigación se completó en tres etapas: un estudio del estado del arte del problema donde se revisaron las bases teóricas de la morfología matemática, sus aplicaciones prácticas y la documentación del Cimahis, seguida de una etapa de planificación y diseño usando la metodología Feature Driven Development (FDD) donde se crearon los artefactos de diseño y se hizo la planeación de actividades que guío la etapa de construcción y prueba en la cual se llevó a cabo la implementación e integración de la herramienta con el prototipo y se hicieron varios test para validar la correctitud en los operadores morfológicos y estimar la eficiencia relativa de la herramienta respecto de otros programas de procesamiento de imágenes. Al final se construyó una herrmienta funcional y eficiente que cuenta con doce operaciones morfológicas, entre las cuales están, el gradiente morfológico, las transformaciones top-hat, bottom-hat y dos operadores de reconstrucción morfológica. La mayoría de los resultados experimentales muestran tiempos de ejecución entre seis y treinta veces más bajos que los generados por las contrapartes disponibles en las herramientas de procesamiento morfológico usadas para hacer las pruebas.Steps prior to the measurement and classification of features and the subsequent characterization of images are filtering and segmentation. Given the usefulness of mathematical morphology in such tasks, the need arose to incorporate a tool for the application of mathematical morphology operators on grayscale images to the Cimahis prototype (Characterization of histological images), currently under development at the University of Carabobo . The research was completed in three stages: a study of the state of the art of the problem where the theoretical bases of mathematical morphology, its practical applications and the Cimahis documentation were reviewed, followed by a planning and design stage using the Feature Driven Development methodology. (FDD) where the design artifacts were created and the planning of activities was carried out that guided the construction and testing stage in which the implementation and integration of the tool with the prototype was carried out and several tests were carried out to validate the correctness in the morphological operators and estimate the relative efficiency of the tool compared to other image processing programs. In the end, a functional and efficient tool was built that has twelve morphological operations, among which are the morphological gradient, the top-hat, bottom-hat transformations and two morphological reconstruction operators. Most of the experimental results show execution times between six and thirty times lower than those generated by the available counterparts in the morphological processing tools used to do the tests
Influence of the microstructure on the creep behaviour of Tin-Silver-Copper solder
A common failure mode of electronic printed circuit boards (PCB’s) is the appearance of cold solder joints between the component and PCB, during product life. This phenomenon is related to solder joint fatigue and is attributed mainly to the mismatch of the coefficients of thermal expansion (CTE) of component-solder-PCB assembly. With today’s solder joint thickness decreasing and increasing working temperatures, among others, the stresses and strains due to temperature changes are growing, leading to limited fatigue life of the products. As fatigue life decreases with increasing plastic strain, creep occurrence should have significant impact, especially during thermal cycles and, thus, should be studied. Through the cooling phase, on the production of PCB assembly’s by the reflow technology, the hoven atmosphere temperature is adjusted in order to control the cooling rate. Narrow criteria is used so as to control the inter-metallic compounds (IMC) thickness, PCB assembly distortion and defects due to thermal shock. The cooling rate also affects solder microstructure, which has direct impact on creep behaviour and, thus, on the soldered joint reliability.
In this paper, a dynamic mechanical analyser (DMA) is used to study the influence of the solder cooling rate on its creep behaviour. SAC405 samples with two distinct cooling rates were produced: inside a hoven cooling and by water quenching. Creep tests were made on three-point-bending clamp configuration, isothermally at 25 °C, 50 °C and 75 °C and under three separate levels of stress, 3, 5 and 9 MPa. The results show that creep behaviour has a noticeable cooling rate dependence. It was also noticed that creep propensity is exacerbated by the temperature at which stresses are applied, especially for the slower cooling rates. Creep mechanisms were related to the solder microstructural constituents, namely by the amount of phases ant their morphology.The authors would like to express his acknowledgments for the
support given by the Portugal Incentive System for Research and
Technological Development. Project in co-promotion
This research is sponsored by the Portugal Incentive System for
Research and Technological Development.
This work is supported by: European Structural and Investment
Funds in the FEDER component, through the Operational
Competitiveness and Internationalization Programme
(COMPETE 2020) [Project nº 002814; Funding Reference:
POCI-01-0247-FEDER-002814]. This work was financed by
FCT, under the Strategic Project UID/SEM/04077/2013;
PEst2015-2020 with the reference UID/CEC/00319/2013 and
UID/FIS/04650/2013
Multiple Sclerosis Patient Management During the COVID-19 Pandemic: Practical Recommendations From the Portuguese Multiple Sclerosis Study Group (GEEM)
The spread of the COVID-19 pandemic has imposed significant challenges on healthcare provision, requiring changes in the conventional patient management, particularly in chronic diseases like multiple sclerosis (MS). To increase patient safety and reduce the risk of infection, while ensuring an appropriate and regular follow-up, tele-medicine gained prominence as a valid alternative to face-to-face appointments. However, the urgency of the implementation and the lack of experience in most MS centers led to "ad hoc" and extremely diverse approaches, which now merit to be standardized and refined. Indeed, while tele-consultation cannot fully replace face-to-face visits, it certainly can, and will, be incorporated as part of the routine care of MS patients in the near future. Bearing this in mind, the Portuguese Multiple Sclerosis Study Group (GEEM) has developed a set of recommendations for the usage of tele-medicine in the management of MS patients, both during the pandemic and in the future. The consensus was obtained through a two-step modified Delphi methodology, resulting in 15 recommendations, which are detailed in the manuscript.The consensus and the publication of this manuscript were supported by an educational grant from Novartis Portugal to the Grupo de Estudos de Esclerose Múltipla. These funds were used to pay the work of the consultancy MOAI, which set up the online questionnaire and helped with writing the summary of the meeting and the first draft of the consensus, and the publishing fee (article processing charge). The funding source had no role in the process and did not influence, by any means, the content of the consensus or the present manuscriptinfo:eu-repo/semantics/publishedVersio
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