294 research outputs found
Manufacturing systems simulation using the principles of system dy
Manufacturing is the largest single contributor to the global economy. The evolution of consumer demands has pressurised companies into producing a larger variety of products, with improved specifications, reduced costs, and shorter lead times. In this context, companies have found simulation techniques useful in their manufacturing systems design processes; simulation based on Discrete Event Simulation (DES) is the preferred technique. The complexity of manufacturing systems, and the mechanisms of DES, means that the simulation task often consumes excessive time and resources, such as data, software, and training.
Evidence suggests that an alternative modelling technique, named System Dynamics
(SD), is also appropriate for conducting this task. SD has been applied successfully in other fields, where its graphical notation is considered beneficial. However, the lack of an SD tool that is tailored toward manufacturing systems has prevented industry from
adopting this technique more extensively.
This thesis determines the extent to which SD can provide a credible alternative to DES in the manufacturing system design process. Information concerning DES, SD and practitioners' needs was gathered from published literature and from an interview
survey. A functional prototype of a tool based on the SD principles, but tailored to model manufacturing systems was then developed. Three case studies then provided valuable information concerning the requirements of industry and the capabilities of the SD technique.
This research programme has found SD to be sufficiently accurate and quicker than
DES tools under certain conditions, requiring less data and skills. In addition, the user interface appears to have had a significant impact on the lack of adoption of SD techniques within the manufacturing sector. Simp1ifications made by this technique can reduce both model building and model execution time, and thus, experimentation time.
However, evidence suggests that DES is still more prevalent, and that further work is required to develop SD based tools tailored to manufacturing systems. Therefore, this thesis provides a much improved understanding of the capabilities of SD as an aid to manufacturing systems design
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Analysis of playing area dimensions in Spanish professional soccer: extrapolation to the design of small-sided games with tactical applications
Caro, O, Zubillaga, A, Fradua, L, and Fernandez-Navarro, J. Analysis of playing area dimensions in Spanish professional soccer: Extrapolation to the design of small-sided games with tactical applications. J Strength Cond Res XX(X): 000–000, 2019—The aims of this study were to examine (a) the width and length dimensions of the playing area in 4v4 situations during competition, (b) the influence of the pitch zone where the ball is on 4v4 dimensions, and (c) the influence of match status on the dimensions of 4v4 situations. Data were collected from 25 matches from the Spanish La Liga of the 2007–2008 season using the Amisco system. Length, width, and individual playing area (IPA) of the rectangle that included the nearest 4 players to the ball from each team were collected in a total of 8,727 4v4 game situations. The pitch zone and match status were also considered for these 4v4 situations. To determine factors that affect 4v4 game situations, 1-way analysis of variance was used. The influence of the pitch zone where 4v4 situations took place showed significant differences (p < 0.001) between the zones where different principles of the game apply. The areas of the 4v4 situations ranged from 14.70 ± 4.69 × 17.18 ± 6 to 17.09 ± 5.16 × 20.34 ± 5.93 m, and the IPA of the 4v4 playing rectangle ranged from 46.33 ± 20 to 35.48 ± 16.95 m2, being larger in the central zones of the pitch. The length of the 4v4 rectangle showed a significant reduction in the closer zones to the goal. Match status did not affect the dimensions of these 4v4 game situations significantly. The findings of this study suggest that the size of 4v4 situations proposed for training should be designed according to the pitch zone where playing actions take place
Evaluating the effectiveness of styles of play in elite soccer
The aim of this study was to evaluate the effectiveness of styles of play in soccer and the influence of contextual variables (i.e. match status, venue and quality of opposition). Team possessions (n = 68,766) from the 380 matches of the 2015–2016 English Premier League season were collected for this study. The Possession Effectiveness Index, based on Expected Goals and Ball Movement Points metrics, was used to measure the effectiveness of team possessions. Linear mixed models were applied to analyse the influence of contextual variables on the effectiveness score for each style. Results showed that the effectiveness of Direct Play, Counterattack, Maintenance and Crossing significantly increased when teams were winning by two or more goals. Counterattack increased its effectiveness when teams were winning by one goal and reduced its effectiveness when losing by one goal. The effectiveness of Direct Play increased when losing by two goals or more. Playing away negatively affected the effectiveness of Direct Play, Maintenance and High Pressure. In addition, playing against a stronger opposition reduced the effectiveness of all styles of play. The results suggest that the effectiveness of styles of play changes under specific circumstances and that not all contextual variables affect them in the same way
Influence of opposition team formation on physical and skill-related performance in a professional soccer team
This study examined the influence of opposition team formation on physical and skill-related performance in a professional soccer team. Performance in forty-five French League 1 matches played over three competitive seasons (2007-08, 2008-09, and 2009-10) was analysed using multi-camera computerised tracking. Players (n=21) in the reference team (using a 4-3-3/4-5-1 formation) were analysed in matches against three opposition team formations: 4-4-2 (11 games), 4-3-3/4-5-1 (16 games) and 4-2-3-1 (18 games). Performance was compared for defending and midfield units as a whole and individually across four positions: fullbacks, central-defenders and central- and wide-midfielders. Collectively, players covered a greater total distance (p<0.05) and distance in low/moderate-intensity running (0-14.3km/h) (p<0.05) in matches against a 4-2-3-1 compared to a 4-4-2 formation. Distance covered in high-intensity (14.4-19.7km/h) and very high-intensity running (≥19.8km/h) was not affected by opposition formation. In contrast, players covered more distance in total high-intensity performance (≥14.4km/h) when the reference team was in possession against a 4-4-2 compared to a 4-2-3-1 formation (p<0.05) while more distance was run at these speeds when the reference team was out of possession against a 4-2-3-1 (p<0.01) and a 4-3-3 (p<0.05) compared to a 4-4-2 formation. Players ran less distance at low/moderate intensities in the second- versus first-half of matches against all three formations (p<0.01 to p<0.05) whereas total distance and high-intensity performance was unaffected. None of the measures of physical performance across the individual playing positions were affected by opposition team formation. Skill-related performance varied according to opposition formation: players as a whole performed more passes versus a 4-4-2 than a 4-2-3-1 (p<0.01), ground and aerial duels versus a 4-2-3-1 compared to a 4-4-2 (both p<0.01); 1-touch passes versus a 4-2-3-1 compared to a 4-4-2 (p<0.01) and a 4-3-3/4-5-1 (p<0.05). The mean number of touches per possession was highest versus a 4-4-2 compared to a 4-3-3/4-5-1 (p<0.01) and a 4-2-3-1 (p<0.01). While skill-related performance across the four individual playing positions was generally unaffected by opposition team formation, mean pass length was greater in central-midfielders against a 4-4-2 compared to 4-3-3/4-5-1 (p<0.05) and 4-2-3-1 (p<0.01) formations. In general, these findings suggest that physical performance in the reference team was not greatly affected by opposition team formation. In contrast, skill-related demands varied substantially according to opponent formation and may have consequences for tactical and technical preparation and team selection policies
Los niveles glauconíticos de la Formación Salamanca, Chubut : su efectividad agronómica como fuente alternativa de fertilizante potásico
391-398The Maastrichtian-Early Palaeocene Salamanca Formation and equivalent marine sequences show several glaucony levels, which could be used as a source of potassium and could partially replace current fertilizer requirements met from import. First agronomic assays are shown comparing the efficiency of greensands (GL) with a traditional potassium fertilizer (KCl). Prospection and sampling took place in the heads of Rio Chico to east of Lago Colhué Huapi, Chubut, where glauconitic levels thickness reach to 20m. This research was separated in phases: phase 1, prospection, sampling, and sedimentological and chemical routine analyses, phase 2a, concentration and ore treatment assays, and phase 2b, agronomic assays. This last phase, was done in culture chamber, with 125 um and 250 um fractions (2,85 and 2,82 percent K 2O respectively) and KCl. Varying the dose, seven treatments were completed. In successive harvests (four in total) was observed that GL1 and GL2 (125), did not present a significantly differential behavior with the control. Both treatments of GL 250 um showed major accumulated biomass, overcoming the control in 44 and 60 percent respectively. As conclusion, better results were obtained by 250 um overcoming even to the KCl fertilization. Probably the major participation of K feldspars in the 125 um and fast leaching of K in this fraction during successive irrigations of soil would originate the minor observed yield. The great areal extension of the Salamanca Formation and the continuity of the glauconitic levels encourage continuing the evaluation as fertilizer or amendment
Los niveles glauconíticos de la Formación Salamanca, Chubut : su efectividad agronómica como fuente alternativa de fertilizante potásico
391-398The Maastrichtian-Early Palaeocene Salamanca Formation and equivalent marine sequences show several glaucony levels, which could be used as a source of potassium and could partially replace current fertilizer requirements met from import. First agronomic assays are shown comparing the efficiency of greensands (GL) with a traditional potassium fertilizer (KCl). Prospection and sampling took place in the heads of Rio Chico to east of Lago Colhué Huapi, Chubut, where glauconitic levels thickness reach to 20m. This research was separated in phases: phase 1, prospection, sampling, and sedimentological and chemical routine analyses, phase 2a, concentration and ore treatment assays, and phase 2b, agronomic assays. This last phase, was done in culture chamber, with 125 um and 250 um fractions (2,85 and 2,82 percent K 2O respectively) and KCl. Varying the dose, seven treatments were completed. In successive harvests (four in total) was observed that GL1 and GL2 (125), did not present a significantly differential behavior with the control. Both treatments of GL 250 um showed major accumulated biomass, overcoming the control in 44 and 60 percent respectively. As conclusion, better results were obtained by 250 um overcoming even to the KCl fertilization. Probably the major participation of K feldspars in the 125 um and fast leaching of K in this fraction during successive irrigations of soil would originate the minor observed yield. The great areal extension of the Salamanca Formation and the continuity of the glauconitic levels encourage continuing the evaluation as fertilizer or amendment
Filling pressures and collagen metabolism in hypertensive patients with heart failure and normal ejection fraction
This study was designed to evaluate the association between circulating biomarkers of collagen metabolism and elevated left-sided filling pressures (FPs), as assessed from elevated estimated pulmonary capillary wedge pressure (ePCWP), in hypertensive patients with heart failure with normal ejection fraction. Echocardiography was performed and ePCWP was calculated from the formula ePCWP=1.90+1.24(maximum early transmitral flow velocity in diastole:tissue Doppler early mitral annulus velocity). The biomarkers of collagen synthesis (carboxy-terminal propeptide of procollagen type I) and degradation (matrix metalloproteinase [MMP] 1 and tissue inhibitor of MMP-1 [TIMP-1]) were analyzed by ELISA methods. Seventy-eight patients with normal FPs (ePCWP 15 mm Hg) were included. Compared with controls, the levels of the 3 biomarkers were increased in the 2 groups of patients. The MMP-1:TIMP-1 ratio, an index of MMP-1 activity, was increased in patients with normal FPs and unchanged in patients with elevated FPs. Patients with elevated FPs exhibited higher TIMP-1 levels and a lower MMP-1:TIMP-1 ratio than patients with normal FPs. ePCWP was independently associated with TIMP-1 (r=0.349; P<0.001) and the MMP-1:TIMP-1 ratio (r=-0.240; P<0.01) in all of the patients. Receiver operating characteristic curves showed that a cutoff value of TIMP-1 of 1557 ng/mL provided 64% sensitivity and 67% specificity for predicting elevated FPs with a relative risk of 3.71 (95% CI: 1.91 to 7.22). These findings suggest that, in hypertensive patients with heart failure with normal ejection fraction and elevated FPs, collagen synthesis predominates over degradation because of a relative excess of TIMP-1. This imbalance can facilitate myocardial fibrosis, which, in turn, may contribute to the elevation of FPs in these patients
Development of New Drugs to Treat <em>Taenia solium</em> Cysticercosis: Targeting 26 kDa Glutathione Transferase
Taenia solium causes neurocysticercosis, a parasitic infection of the central nervous system in humans. The costs of management, treatment, and diagnosis of patients with neurocysticercosis are high, and some patients do not respond to the currently available treatments. Helminth cytosolic glutathione transferases (GSTs) are essential enzymes involved in the regulation of immune responses, transport, and detoxification. In T. solium, three cytosolic GSTs with molecular masses of 26.5 (Ts26GST), 25.5 (Ts25GST), and 24.3 kDa (TsMσGST), classified as mu-alpha, mu and sigma GST-classes, respectively, constitute the main detoxification system, and they may be immune targets for the development of vaccines and new anthelmintics. We performed a successful virtual screen, and identified I7, a novel selective inhibitor of Ts26GST that showed a non-competitive inhibition mechanism towards substrate glutathione with a Ki of 55.7 mM and mixed inhibition towards the electrophilic substrate 1-chloro-2,4-dinitrobenzene with a Ki of 8.64 mM. Docking simulation studies showed that I7 can bind to a site that is adjacent to the electrophilic site and the furthest from the glutathione site. This new inhibitor of Ts26GST will be used as a lead molecule to develop new effective and safe drugs against diseases caused by T. solium
Elaboración de una Unidad Didáctica de apoyo a la enseñanza presencial de programas y guías de aprendizaje a través de las TIC
Una de las muchas competencias que un docente debe desarrollar para realizar una docencia de calidad es la planificación de sus asignaturas, lo cual en la Universidad de Deusto se verifica a través del programa y de la guía de aprendizaje. La elaboración de estos dos instrumentos requiere contar, no solo con cursos presenciales, sino con documentación de apoyo actualizada y fácilmente accesible. A través de un proyecto de innovación y gracias a la utilización de las TIC se ha diseñado, implementado y validado una “asignatura para docentes”, que acompaña a dichos cursos presenciales, en la plataforma institucional. La novedad no es el uso de la plataforma en sí, sino la forma en que se ha diseñado la Unidad Didáctica: siguiendo el ciclo de aprendizaje establecido en la Universidad, y utilizando metodologías activas, recursos variados y un proceso de evaluación formativa y feedback. De este modo, no solo se forma en contenidos, sino que se ofrece al profesorado una Unidad que le sirve como ejemplo de lo que se le pide desarrollar en sus propias asignaturas. Los resultados en cuanto a seguimiento de fases, cumplimiento de objetivos e indicadores de impacto han sido muy satisfactorios
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