259 research outputs found
Genetic algorithms for the scheduling in additive manufacturing
[EN] Genetic Algorithms (GAs) are introduced to tackle the packing problem. The scheduling in Additive Manufacturing (AM) is also dealt with to set up a managed market, called “Lonja3D”. This will enable to determine an alternative tool through the combinatorial auctions, wherein the customers will be able to purchase the products at the best prices from the manufacturers. Moreover, the manufacturers will be able to optimize the production capacity and to decrease the operating costs in each case.This research has been partially financed by the project: “Lonja de Impresión 3D para la Industria
4.0 y la Empresa Digital (LONJA3D)” funded by the Regional Government of Castile and Leon and
the European Regional Development Fund (ERDF, FEDER) with grant VA049P17Castillo-Rivera, S.; De Antón, J.; Del Olmo, R.; Pajares, J.; López-Paredes, A. (2020). Genetic algorithms for the scheduling in additive manufacturing. International Journal of Production Management and Engineering. 8(2):59-63. https://doi.org/10.4995/ijpme.2020.12173OJS596382Ahsan, A., Habib, A., Khoda, B. (2015). Resource based process planning for additive manufacturing. Computer-Aided Design, 69, 112-125. https://doi.org/10.1016/j.cad.2015.03.006Araújo, L., Özcan, E., Atkin, J., Baumers, M., Tuck, C., Hague, R. (2015). Toward better build volume packing in additive manufacturing: classification of existing problems and benchmarks. 26th Annual International Solid Freeform Fabrication Symposium - an Additive Manufacturing Conference, 401-410.Berman, B. (2012). 3-D printing: The new industrial revolution. Business Horizons, 55: 155-162. https://doi.org/10.1016/j.bushor.2011.11.003Canellidis, V., Dedoussis, V., Mantzouratos, N., Sofianopoulou, S. (2006). Preprocessing methodology for optimizing stereolithography apparatus build performance. Computers in Industry, 57, 424-436. https://doi.org/10.1016/j.compind.2006.02.004Chergui, A., Hadj-Hamoub, K., Vignata, F. (2018). Production scheduling and nesting in additive manufacturing. Computers & Industrial Engineering, 126, 292-301. https://doi.org/10.1016/j.cie.2018.09.048Demirel, E., Özelkan, E.C., Lim, C. (2018). Aggregate planning with flexibility requirements profile. International Journal of Production Economics, 202, 45-58. https://doi.org/10.1016/j.ijpe.2018.05.001Fera, M., Fruggiero, F., Lambiase, A., Macchiaroli, R., Todisco, V. (2018). A modified genetic algorithm for time and cost optimization of an additive manufacturing single-machine scheduling. International Journal of Industrial Engineering Computations, 9, 423-438. https://doi.org/10.5267/j.ijiec.2018.1.001Hopper, E., Turton, B. (1997). Application of genetic algorithms to packing problems - A Review. Proceedings of the 2nd Online World Conference on Soft Computing in Engineering Design and Manufacturing, Springer Verlag, London, 279-288. https://doi.org/10.1007/978-1-4471-0427-8_30Ikonen, I., Biles, W.E., Kumar, A., Wissel, J.C., Ragade, R.K. (1997). A genetic algorithm for packing three-dimensional non-convex objects having cavities and holes. ICGA, 591-598.Kim, K.H., Egbelu, P.J. (1999). Scheduling in a production environment with multiple process plans per job. International Journal of Production Research, 37, 2725-2753. https://doi.org/10.1080/002075499190491Lawrynowicz, A. (2011). Genetic algorithms for solving scheduling problems in manufacturing systems. Foundations of Management, 3(2), 7-26. https://doi.org/10.2478/v10238-012-0039-2Li, Q., Kucukkoc, I., Zhang, D. (2017). Production planning in additive manufacturing and 3D printing. Computers and Operations Research, 83, 157-172. https://doi.org/10.1016/j.cor.2017.01.013Milošević, M., Lukić, D., Đurđev, M., Vukman, J., Antić, A. (2016). Genetic Algorithms in Integrated Process Planning and Scheduling-A State of The Art Review. Proceedings in Manufacturing Systems, 11(2), 83-88.Pour, M.A., Zanardini, M., Bacchetti, A., Zanoni, S. (2016). Additive manufacturing impacts on productions and logistics systems. IFAC, 49(12), 1679-1684. https://doi.org/10.1016/j.ifacol.2016.07.822Wilhelm, W.E., Shin, H.M. (1985). Effectiveness of Alternate Operations in a Flexible Manufacturing System. International Journal of Production Research, 23(1), 65-79. https://doi.org/10.1080/00207548508904691Xirouchakis, P., Kiritsis, D., Persson, J.G. (1998). A Petri net Technique for Process Planning Cost Estimation. Annals of the CIRP, 47(1), 427-430. https://doi.org/10.1016/S0007-8506(07)62867-4Zhang, Y., Bernard, A., Gupta, R.K., Harik, R. (2014). Evaluating the design for additive manufacturing: a process planning perspective. Procedia CIRP, 21, 144-150. https://doi.org/10.1016/j.procir.2014.03.17
Prevalence of depression during the COVID-19 outbreak: A meta-analysis of community-based studies
Introduction: COVID-19 pandemic, declared on March 11, 2020, constitute an extraordinary health, social and economic global challenge. The impact on people''s mental health is expected to be high. This paper sought to systematically review community-based studies on depression conducted during the COVID-19 and estimate the pooled prevalence of depression.
Method: We searched for cross-sectional, community-based studies listed on PubMed or Web of Science from January 1, 2020 to May 8, 2020 that reported prevalence of depression. A random effect model was used to estimate the pooled proportion of depression.
Results: A total of 12 studies were included in the meta-analysis, with prevalence rates of depression ranging from 7.45% to 48.30%. The pooled prevalence of depression was 25% (95% CI: 18% - 33%), with significant heterogeneity between studies (I2 = 99.60%, p < .001).
Conclusions: Compared with a global estimated prevalence of depression of 3.44% in 2017, our pooled prevalence of 25% appears to be 7 times higher, thus suggesting an important impact of the COVID-19 outbreak on people's mental health. Addressing mental health during and after this global health crisis should be placed into the international and national public health agenda to improve citizens’ wellbeing
Structural and magnetic properties of Ni0.8Fe0.2/Ti nanoscale multilayers
The influence of the thickness of the Ni0.8Fe0.2 (Permalloy, Py) layers on the structural and magnetic properties of magnetron sputtered Py/Ti multilayers was studied. The thickness of the Py layers was varied in the interval of 8 to 30 Å. X-ray reflectivity scans evidence the existence of a well-defined layered structure in all the samples considered, but also the presence of a complex intermixed interface. The shape of both the temperature dependence of magnetization and the hysteresis loops of the multilayered structures depends strongly on Py thickness. Magnetic and reflectivity measurements were comparatively analyzed in order to better understand the structure of the samples, and specifically, their interfaces. In particular, the presence of small superparamagnetic Py at the interfaces of the samples, especially evident in the samples with the thinnest Py layers, seems confirmed by the magnetic measurements, agreeing well with the reflectivity results. © 2018 by the authors.1 Instituto Regional de Investigación Científica Aplicada (IRICA) and Departamento de Física Aplicada, Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain; [email protected] (J.A.G.); [email protected] (J.P.A.) 2 Department of Solid State Magnetism, Institute of Natural Sciences and Mathematics, Ural Federal University, 620002 Ekaterinburg, Russia; [email protected] (A.V.S.); [email protected] (G.V.K.) 3 Departamento de Electricidad y Electrónica, Universidad del País Vasco (UPV/EHU), 48080 Bilbao, SpainFunding: The research was supported by the Ministry of Education and Science of the Russian Federation (Agreement no. 02.A03.21.0006) and by the Spanish projects MAT2014-58034-R (MINECO/AEI/FEDER, EU) and PEII-2014-042-P (JCCM/FEDER, EU)
One-year observation of leflunomide effectiveness and saftey in juvenile idiopathic arthritis : a clinical practice review (preliminary data)
The prevalence of depression, anxiety and stress and their associated factors in college students
Aim: To estimate the prevalence of symptoms of depression, anxiety, stress and associated factors in a population of college students.
Method: Cross-sectional study of psychological distress measured through the Depression, Anxiety and Stress Scale (DASS-21) in a sample of 1074 college students.
Results: We found a moderate prevalence of depression (18, 4%), anxiety (23, 6%) and stress (34, 5%) symptoms in our study population. Being <21, having problematic Internet use behavior, smoking, presenting insomnia and having a low self-esteem were independently associated with symptoms of depression, anxiety and stress. Being a woman, living with their family, having a stable partner, consuming alcohol frequently and having poor nutritional habits were significantly associated with symptoms of stress; lacking a stable partner was significantly associated with depressive symptoms; and frequent consumption of alcohol was significantly associated with symptoms of anxiety.
Conclusion: We found a moderate prevalence of depression, anxiety and stress symptoms in our population. Interventions aimed at promoting mental health among college students should be implemented
A child with resistant Kawasaki disease successfully treated with anakinra: a case report
Background: Kawasaki disease (KD) is an acute self-limited systemic vasculitis of unknown etiology. Intravenous immunoglobulin (IVIG) is an effective treatment and decreases the risk of cardiac complications to less than 5%. In spite of its effectiveness, some children do not respond to this therapy and still develop coronary aneurysms (CAA). The optimal treatment for IVIG non-responsive patients remains controversial although corticoids have been suggested to be an effective treatment in some patients. For those patients still resistant to IVIG and corticoids, interleukin-1 receptor antagonists (IL-1RA) such anakinra could be an alternative. Case presentation: We present a 3 year-old Caucasian patient with KD without cardiac complications but with important resistance to treatment. After becoming resistant to IVIG and corticoids, anakinra proved to be an effective treatment. Conclusions: To our knowledge, this is the first report of the utility of IL-1RA in refractory KD without coronary impairment. The patient fulfilled the classical criteria for KD and, after becoming resistant to first and second line treatments, anakinra proved to be an effective treatment. Further studies are required to determine if this is an effective treatment option for other cases of resistant Kawasaki disease
Validation of OMI-TOMS and OMI-DOAS total ozone column using five Brewer spectroradiometers at the Iberian peninsula
This article focuses on the comparison of the total ozone column data from the Ozone
Monitoring Instrument (OMI) flying aboard the NASA EOS-Aura satellite platform with
ground-based measurement recorded by Brewer spectroradiometers located at five
Spanish remote sensing ground stations between January 2005 and December 2007. The
satellite data are derived from two algorithms: OMI Total Ozone Mapping Spectrometer
(OMI-TOMS) and OMI Differential Optical Absorption Spectroscopy (OMI-DOAS).
The largest relative differences between these OMI total ozone column estimates reach 5%
with a significant seasonal dependence. The agreement between OMI ozone data and
Brewer measurements is excellent. Total ozone columns from OMI-TOMS are on average
a mere 2.0% lower than Brewer data. For OMI-DOAS data the bias is a mere 1.4%.
However, the relative difference between OMI-TOMS and Brewer measurements shows
a notably lower seasonal dependence and variability than the differences between
OMI-DOAS and ground-based data. For both OMI ozone data products these relative
differences show significant dependence on the satellite ground pixel solar zenith angle
for cloud-free cases as well as for cloudy conditions. However, the OMI ozone data
products are shown to reveal opposite behavior with respect to the two antagonistic
sky conditions. No significant dependency of the ground-based to satellite-based
differences with respect to the satellite cross-track position is seen for either OMI retrieval
algorithm.This work was partially supported by Ministerio de Educación y Ciencia under Project CGL2005-05693-C03-03/CLI and by Ministerio de Ciencia e Innovación under project CGL2008-05939-C03-02/CLI
A novel score for predicting alzheimer’s disease risk from late life psychopathological and health risk factors
With the increasing size of the aging population, dementia risk reduction has become a main public health concern. Dementia risk models or indices may help to identify individuals in the community at high risk to develop dementia. We have aimed to develop a novel dementia risk index focused on the late-life (65 years or more) population, that addresses risk factors for Alz-heimer’s disease (AD) easily identifiable at primary care settings. These risk factors include some shown to be associated with the risk of AD but not featured in existing indices, such as hearing loss and anxiety. Our index is also the first to account for the competing risk of death. The Zaragoza Dementia and Depression Project (ZARADEMP) Alzheimer Dementia Risk Score predicts an indi-vidual´s risk of developing AD within 5 years. The probability of late onset AD significantly in-creases in those with risk scores between 21 and 28 and, furthermore, is almost 4-fold higher for those with risk scores of 29 or higher. Our index may provide a practical instrument to identify subjects at high risk of AD and to design preventive strategies targeting the contributing risk factors
Anhedonia as a potential risk factor of alzheimer’s disease in a community-dwelling elderly sample: Results from the zarademp project
(1) Introduction: Dementia is a major public health problem, and Alzheimer’s disease (AD) is the most frequent subtype. Clarifying the potential risk factors is necessary in order to improve dementia-prevention strategies and quality of life. Here, our purpose was to investigate the role of the absence of hedonic tone; anhedonia, understood as the reduction on previous enjoyable daily activities, which occasionally is underdetected and underdiagnosed; and the risk of developing AD in a cognitively unimpaired and non-depressed population sample.
(2) Method: We used data from the Zaragoza Dementia and Depression (ZARADEMP) project, a longitudinal epidemiological study on dementia and depression. After excluding subjects with dementia, a sample of 2830 dwellers aged =65 years was followed for 4.5 years. The geriatric mental state examination was used to identify cases of anhedonia. AD was diagnosed by a panel of research psychiatrists according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria. A multivariate survival analysis and Cox proportional hazards regression model were performed, and the analysis was controlled by an analysis for the presence of clinically significant depression.
(3) Results: We found a significant association between anhedonia cases and AD risk in the univariate analysis (hazard ratio (HR): 2.37; 95% CI: 1.04–5.40). This association persisted more strongly in the fully adjusted model.
(4) Conclusions: Identifying cognitively intact individuals with anhedonia is a priority to implement preventive strategies that could delay the progression of cognitive and functional impairment in subjects at risk of AD
Treatment patterns for metastatic colorectal cancer in Spain
Abstract Purpose The primary aim of this retrospective study was to describe the treatment patterns according to the type of treatment received by patients with metastatic colorectal cancer (mCRC) in Spain. Methods This was a retrospective, observational, multicenter study performed by 33 sites throughout Spain that included consecutive patients aged 18 years or older who had received or were receiving treatment for mCRC. Results At the time of inclusion, of the 873 evaluable patients, 507 (58%) had received two lines, 235 (27%) had received three lines, 106 (12%) had received four lines, and the remaining patients had received up to ten lines. The most frequent chemotherapy schemes were the FOLFOX or CAPOX regimens (66%) for frst-line treatment, FOLFOX, CAPOX or FOLFIRI (70%) for second-line treatment, and FOLFOX, FOLFIRI or other fuoropyrimidine-based regimens for third- and fourth-line (over 60%) treatment. Sixty percent of patients received targeted therapy as part of their frst-line treatment, and this proportion increased up to approximately 70% of patients as part of the second-line of treatment. A relevant proportion of patients were treated with unknown KRAS, and especially the BRAF, mutation statuses. Conclusions This study reveals inconsistencies regarding adherence to the recommendations of the ESMO guidelines for the management of mCRC in Spain. Improved adherence to the standard practice described in such guidelines for the determination of RAS and BRAF mutation statuses and the use of targeted therapies in frst-line treatment should be considered to guarantee that patients can beneft from the best therapeutic approaches available. Keywords Colorectal cancer · Metastatic · Treatment patterns · KRAS/BRAF mutation status · Clinical practice guidelin
- …