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

Eugenio Imaz: el fondo espiritual de un pensador.

Sin resume

Collective risk assessment in Affordable Care Act markets : a Bayesian hierarchical model

Mestrado em Actuarial ScienceThe changes that the Affordable Care Act introduced to the US health insurance market have entirely altered the traditional ratemaking process. Precisely, the cre ation of statewide community rating schemes and a guaranteed issue has facilitated insurance coverage to the high-risk population, leading to massive changes in risk pool compositions. The implementation of Risk Adjustment has neutralized some of the consequences of limiting premium variation in the market. However, setting appropriate rate levels has remained cumbersome due to the uncertainty about the statewide risk pool. Many insurers, who could not quantify the health risk associ ated with the statewide yearly enrollment, had to face unexpectedly high payments on risk equalization. Natsis (2019) stated that in this environment, the use of tradi tional univariate techniques to project statewide health care costs could be potentially misleading. This thesis proposes a Bayesian approach to reflect important sources of uncertainty over statewide actuarial estimates. The aggregate loss is modeled with a novel collective risk model based on a Generalized Beta Prime (GBP) distribution, accounting for long tail risks and changes in risk pool compositions. The GBP is presented with a mean-dispersion parametrization, which allows the introduction of a hierarchical prior specification over the state-specific means. This parameter struc ture, responsible of quantifying uncertainty and sharing information among states, is a cornerstone of the adopted collective risk model. Using the Commercial Health Care data extract published by the Society of Actuaries (2019), the model is applied on the Surgical and Transplant service category. The resulting heavy-tailed posteri ors of the nationwide service means illustrate the high variation of inpatient medical costs. Moreover, the posteriors of the statewide aggregate claims remain highly right skewed, reflecting the risk of facing sicker populations and high-cost treatments at individual claim level.As alterações que o Affordable Care Act introduziu tiveram um impacto significativo no processo de tarifação de seguros de saúde nos Estados Unidos. De forma mais precisa, a criação de um sistema de tarifação regulado, e com cobertura garantida, facilitou o acesso de seguro à população de risco. A inclusão destes indivıduos originou grandes alterações na composição dos grupos de risco de cada estado. A implementação da metodologia do Risk Adjustment neutralizou algumas das consequências de restringir as variações de prémios no mercado. No entanto, a estimativa dos níveis de prémios permaneceu complicada devido à incerteza dos riscos coletivos. Muitas seguradoras, que não foram capazes de quantificar corretamente o risco de saúde associado à carteira anual do estado, depararam-se inesperadamente com pagamentos muito altos do Risk Adjustment. De facto, Natsis (2019) afirmou que a utilização de técnicas univariadas para projectar os custos médicos neste novo panorama pode produzir resultados enganadores. Nesta tese propomos uma abordagem bayesiana ao problema que pretende incorporar as diversas formas de incerteza presentes em estimativas actuariais ao nível estadual. Implementamos um modelo de risco inovador, baseado na distribuição beta-linha generalizada (BLG), distribuição esta que é capaz de acomodar caudas pesadas e heterogeneidade na composição dos grupos de risco. Apresentamos uma parametrização da distribuição BLG baseada na média e na dispersão, o que permite introduzir uma estrutura paramétrica hierárquica no custo médio. Esta estrutura de parâmetros é a base do modelo para quantificar a incerteza e partilhar informações entre diferentes estados. Utilizando um subconjunto dos dados publicados pela Society of Actuaries em 2019, denominados Commercial Health Care Data, implementamos o nosso modelo no contexto dos custos associados à categoria Surgical and Transplant. Mostramos que a variabilidade nos custos médicos hospitalares de doentes internados conduz a distribuições das médias nacionais a posteriori com caudas mais pesadas. Adicionalmente, as distribuições a posteriori dos sinistros agregados apresentam um enviezamento à direita muito pronunciado, reflectindo a inclusão no mercado de indivíduos pouco saudáaveis e com custos de tratamentos muito altos.info:eu-repo/semantics/publishedVersio

Biopolítica del niño sano: procreación biológica, social y jurídica

La biopolítica refiere al ejercicio del poder sobre el ser humano en tanto ser viviente y constructo subjetivo. El trabajo en pediatría supone la tensión entre la nuda vida del zoé y y el bios, o vida relacional del ciudadano, es una constante. Los programas pediátricos que tipifican los cuidados y atención que se han de desplegar sobre el niño sano representan la versión socialmente más legitimada y técnicamente más desarrollada de un modelo de control sobre la procreación individual y la reproducción colectiva. El saber pediátrico sanciona los cánones de la parentalidad normalizada proponiendo las bases de las dimensiones fisiológicas, psicosociales y ciudadanas de niños y niñas. Bilogía y crianza quedan entreveradas inextricablemente. La pediatría reconoce la encomienda de gestionar el niño entendido como ente previo a un adulto, supervisando su crecimiento y desarrollo cognitivo, fisiológico y emocional de forma que su normalidad psicofisiológica adelante los límites a su normalidad social. Se propone aquí cartografiar los campos escolar, legal y social resultantes de dicho modelo normativo.Palabras clave: Biopolítica, procreación, normalización, crianza , parentalidad.AbstractBiopolitics refers to the exercise of power over the human being as a living being and to the construction of subjectivity. Pediatrics portrays a tension between the bare life of zoe and the relational life of bios as a constant. Pediatrics programs that typify the care and attention given to healthy children represent the most socially legitimized and the most technically developed model of control over individual and collective procreation and reproduction. Pediatric knowledge legitimates the canons of standardized parenting and sets the baseline for our understanding of the physiological, psychosocial and civic dimensions of children. Nature and nurture become mutually embedded. Pediatrics recognizes its task as handling the child, understood as an entity prior to the adult. It supervises the child’s growth and cognitive, physiological and emotional development, such that the child’s psychophysiological normality points out the limits of his or her social normality. I map the scholarly, legal and social fields that result from this normative model.Keywords: Biopolitics, procreation, normalization, nurture, parenting

Trichoderma koningii as a biomineralizing fungous agent of calcium oxalate crystals in typical Argiudolls of the Los Padres Lake natural reserve (Buenos Aires, Argentina)

The aim of the present study, performed on typical Argiudolls in a natural reserve with little or no anthropic impact, was to characterize the fungous biomineralizing process of calcium oxalate crystals in organic horizons of the soil. The chosen sites possessed different plant cover, identified as acacia woods and grassy meadows with particular micro environmental conditions that have differing effects in the process of biomineralization. The contribution of the plant material in the soil is a key factor since 1) it generates the particular composition of the organic horizons, 2) it determines the nature of decomposing organisms, and 3) it affects the presence, composition and development of biominerals. According to the results obtained, the acacia woods prove to be a site comparatively more favorable to the fungous biomineralizing process. This makes itself manifest in the greater abundance and development of crystals in the organic horizons of the soil, resulting in whewellite (CaC2O4 · H2O) and weddellite (CaC2O4 · (2 + x) H2O) regarding biomineral species developed, the latter being the major component. The observation of both species of biominerals is noteworthy since it represents the first cited in the country. The isolated fungous organisms were Trichoderma koningii, and Absidia corymbifera. T. koningii was identified as the most active biomineralizing organism thus constituting the first reference to indicate this species as a biomineral producing agent.Facultad de Ciencias Naturales y MuseoInstituto de Botánica "Dr. Carlos Spegazzini

Sperm and northern bottlenose whale interactions with deep-water trawlers in the western North Atlantic

An emerging explorer grant from National Geographic (#4711-6) and funding from Fisheries and Oceans Canada supported fieldwork conducted by LF in the study area between 2015-2017.Commercial fisheries have increased in all the world’s oceans with diverse unintended impacts on marine ecosystems. As a result of resource overlap, interactions between cetaceans and fisheries are a common occurrence and, in many cases, can give rise to significant conservation issues. Research on the distribution and types of such interactions is important for efficient management. In this study, we describe the behaviors of two whale species: sperm whales (Physeter macrocephalus) and northern bottlenose whales (Hyperoodon ampullatus), interacting with benthic trawlers fishing off the eastern Grand Banks of the western North Atlantic in 2007. Whale interactions were only observed when vessels were targeting Greenland halibut (Reinhardtius hippoglossoides) in deep-water fishing areas and were most common during net hauling. Sperm whales and northern bottlenose whales appeared to engage in feeding behavior close to the surface during hauling, especially during the latter stages, suggesting they targeted fish escapees rather than discards. Using photo-identification methods, seven individual sperm whales were identified with multiple resights of six individuals being recorded over an almost two month period. The maximum distance between two resights was 234 km, suggesting individual sperm whales were repeatedly targeting and even following fishing vessels over multiple days and between fishing areas. By contrast, there were no photographic resights of individual northern bottlenose whales within this study, or with substantial photo-identification catalogues from other adjacent high density areas, suggesting that individuals of this species may be less likely to follow vessels or move between areas. This study documents the earliest confirmed records of northern bottlenose whales in this remote region. These interactions and high encounter rates may indicate that adjacent populations are recovering from the previous century of commercial whaling. Our study provides new insights and details on whale-fisheries interactions, which can inform future research and help managers understand the real and perceived impacts of depredation behaviour on fisheries and whales.Publisher PDFPeer reviewe

Extended Enolates: Versatile Intermediates for Asymmetric C-H Functionalization via Noncovalent Catalysis

Catalyst-controlled functionalization of unmodified carbonyl compounds is a relevant operation in organic synthesis, especially when high levels of site- and stereo-selectivity can be attained. This objective is now within reach for some subsets of enolizable substrates using various types of activation mechanisms. Recent contributions to this area include enantioselective transformations that proceed via transiently generated noncovalent di(tri)enolate-catalyst coordination species. While relatively easier to form than simple enolate congeners, di(tri)enolates are ambifunctional in nature and so control of the reaction regioselectivity becomes an issue. This Minireview discusses in some detail this and other problems, and how noncovalent activation approaches based on metallic and metal free catalysts have been developed to advance the field.We thank the University of the Basque Country UPV/EHU (UFI QOSYC 11/22), the Basque Government (grant IT-1236-19) and Ministerio de Ciencia e Innovation (grant PID2019109633GB C21), Spain, for their continuous financial support. Documen

Nonlinear implementable control of a dual active bridge series resonant converter

This paper presents a novel control strategy for a Dual Active Bridge Series Resonant Converter (DAB-SRC). The strategy seeks to ensure the stability of the converter over its entire dynamic range while enhances the transient response. Both properties allow the use of the converter in new applications where fast dynamics are required, surpassing the performance of existing feedback loops. Starting from the generalized averaged model of the converter, we propose a nonlinear control strategy by means of Lyapunov's stability theory. After that, we derive a series of modifications in order to implement the strategy in a microcontroller or a DSP, including a sensorless method to tackle the lack of measurements of certain variables and an adaptive control law to deal with uncertain parameters in the model. The strategy is evaluated in simulations and experiments, employing a commercial converter and comparing the results with other control policies

Diseño de ondulador de 1kW para alimentación de maniobra de ascensor desde baterías de 48V

De la necesidad por parte de la empresa Epic Power por reducir costes, éste trabajo de fin de grado ha cobrado forma. Se busca a partir de este trabajo la consecución de un ondulador de bajo coste y alta eficiencia cumplir todos los requerimientos que demanda el mercado. Por ello se ha hecho un estudio de los diseños de onduladores actuales para su compresión y posterior desarrollo y cálculo. Además dimensionamiento de los componentes, simulación de las topologías y cálculo de eficiencias y costes se han llevado a cabo. Todo ello llevará a la selección de una de las topologías como más adecuada para la aplicación

Trichoderma koningii as a biomineralizing fungous agent of calcium oxalate crystals in typical Argiudolls of the Los Padres Lake natural reserve (Buenos Aires, Argentina)

The aim of the present study, performed on typical Argiudolls in a natural reserve with little or no anthropic impact, was to characterize the fungous biomineralizing process of calcium oxalate crystals in organic horizons of the soil. The chosen sites possessed different plant cover, identified as acacia woods and grassy meadows with particular micro environmental conditions that have differing effects in the process of biomineralization. The contribution of the plant material in the soil is a key factor since 1) it generates the particular composition of the organic horizons, 2) it determines the nature of decomposing organisms, and 3) it affects the presence, composition and development of biominerals. According to the results obtained, the acacia woods prove to be a site comparatively more favorable to the fungous biomineralizing process. This makes itself manifest in the greater abundance and development of crystals in the organic horizons of the soil, resulting in whewellite (CaC2O4 · H2O) and weddellite (CaC2O4 · (2 + x) H2O) regarding biomineral species developed, the latter being the major component. The observation of both species of biominerals is noteworthy since it represents the first cited in the country. The isolated fungous organisms were Trichoderma koningii, and Absidia corymbifera. T. koningii was identified as the most active biomineralizing organism thus constituting the first reference to indicate this species as a biomineral producing agent.Facultad de Ciencias Naturales y MuseoInstituto de Botánica "Dr. Carlos Spegazzini