Symbulator : un simulador simbólico de circuitos para calculadora

Peer Reviewe

Symbulator : un simulador simbólico de circuitos para calculadora

Peer Reviewe

El día de las moscas

Cuando la tercera mosca cayó en su taza de café, Ceferino se decidió a romper finalmente el silencio. —Ya no se aguantan las moscas en esta casa. Aunque habló en el mismo tono cortante que había venido usando por años, le pareció notar algo nuevo en su propia voz. El trío de moscas seguía girando sobre el espiral de espuma, batiendo sus patitas negras como un diminuto ballet fúnebre. Ceferino repasó en su mente el sonido de sus palabras. No había hablado en meses, desde la última pelea con su mujer. Tal vez la falta de ejercicio de sus cuerdas vocales las había atrofiado

Replanteando la Estrategia de Cadena de Suministro: Una Guía Breve

Si usted es un gerente de cadena de suministro, es posible que sepa por experiencia, que una variedad de eventos pueden hacerle preguntarse si es el momento de revisar la estrategia que implementa en ella. Sea por cambios internos, como una revisión fundamental de la estrategia de negocio de la empresa oel lanzamiento de nuevos productos, o sea por cambios exter-nos como la entrada en vigor de regulaciones más estrictas, lallegada al mercado de tecnologías disruptivas, u otros cambiosexternos que alteran el entorno de la organización. Inclusopuede ser el cambio natural del ciclo de vida de un producto.Cada uno de estos eventos determina la necesidad de hacer unalto, y replantear la estrategia de cadena de suministro em-pleada por su organización hasta ese momento, para asegu-rarse que esta sigue siendo válida. Sin embargo, replantear una estrategia de cadena de sumi-nistro no es un problema trivial. Las cadenas de suministro tien-den a ser estructuras bastante complejas, y el acto de pensar estratégicamente sobre ellas, lo que en inglés se denomina, análogamente, “estrategizar” la cadena de suministro, refleja esta complejidad. La ausencia de una respuesta clara en la lite-ratura de gestión de la cadena de suministro, sobre cómo replan-tear la estrategia de cadena de suministro de una organización, complica aún más lo que es de por sí un problema desafiante. Entre 2006 y 2016, un equipo de investigadores del Centro de Transporte y Logística (CTL) del MIT exploró el problema de la estrategia de la cadena de suministro, como parte del Proyecto Supply Chain 2020. Luego de una década de investi-gación en colaboración con organizaciones de clase mundial, se lograron avances significativos. Todavía existen muchas pregun-tas que siguen sin responderse y seguirán siendo exploradas por una rama del Proyecto Supply Chain 2020, llamado “Laboratorio de Estrategia de la Cadena de Suministro” del MIT. Pero cree-mos que es hora de compartir con la comunidad de gerentes de cadena de suministro los conocimientos que hemos adquirido hasta el momento sobre cómo replantear la estrategia de cadena de suministro de una organización. Ése precisamente es el propósito de este libro. Aunque re-conocemos que es una obra en progreso, abarca gran parte de nuestras consideraciones sobre el tema. Nuestro plan es conti-nuar actualizando este documento a medida que se llevan a cabo nuevos proyectos y se abordan nuevas preguntas. Pero, como una primera versión, debería funcionar

Planeamiento estratégico para Agroforestal Selva Peruana S.A.C.

Este plan estratégico se ha elaborado para la empresa Agroforestal Selva Peruana S.A.C., siguiendo la metodología del Proceso Estratégico, diseñado por D’Alessio (2013). La organización se encuentra ubicada en la provincia de Oxapampa, departamento de Pasco, en un terreno de 100 hectáreas a 2,400 m.s.n.m. En la actualidad tienen 28,000 cafetos sembrados en un espacio de siete hectáreas. La diferenciación de esta empresa está en producir café orgánico, con la visión de generar alta productividad, con calidad y acceso directo al mercado extranjero. De esta forma brindará rentabilidad a sus accionistas, siendo socialmente responsables. Los objetivos de largo plazo establecen que la empresa exportará 60 toneladas de café orgánico en el año 2025, ya que contará con un rendimiento de 655 kilogramos por hectárea de cultivo. Todo esto bajo las condiciones de la certificación Bird Friendly, con empleados capacitados, a quienes se les brindará seguridad en el desempeño de sus labores. A lo largo de este documento se presentaron 15 estrategias que fueron evaluadas para determinar cuáles contribuían con el logro de los objetivos y cuáles no, seleccionando seis de ellas. En los próximos 10 años, Agroforestal Selva Peruana deberá beneficiar, tostar y empacar café para la exportación, con una marca propia. Estas exportaciones estarán enfocadas no solo al consumo de café en el hogar sino a cafeterías y restaurantes, utilizando los servicios de un bróker especializado en cada mercado de destino, siendo Estados Unidos el principal. De esta manera se adquiere conocimiento sobre dichos mercados y la empresa tendrá la capacidad de innovar y mejorar continuamente. Al eliminar el uso de un acopiador local, se incrementa el precio que se recibirá y por lo tanto el rendimiento sobre la inversión. Pero para ello es necesario contar con procesos estandarizados y personal calificado, que preferiblemente será reclutado en la misma zona del cultivo para promover el desarrollo económico de la regiónThis strategic plan has been developed for Agroforestal Selva Peruana S.A.C., using the Strategic Process, created by D’Alessio (2013). This company that is located in the province of Oxapampa, Department of Pasco, in an area of 100 acres at 2,400 meters above sea level. Currently owns 28,000 coffee trees planted on an area of seven acres. Differentiation of this company is to produce organic coffee, with a view to generate high productivity, quality and access to the foreign market. This will provide returns to its shareholders, being socially responsible. The long-term objectives state that the company will export 60 tons of organic coffee in 2025, because it will have a yield of 655 kg per hectare of crop. All this under the conditions of the Bird Friendly certification, with trained employees, working under safe conditions. Throughout this document 15 strategies were evaluated to determine that six eight contribute to achieve the goals of the organization, according to its vision and mission. Over the next 10 years, Agroforestal Selva Peruana will process, roast and package coffee for exports, with its own recognized brand. These exports will focus not only coffee consumption at home but to cafes and restaurants, using the services of a specialized broker each target market. In this way knowledge is acquired on such markets and the company will have the ability to innovate and continually improve. By eliminating the use of a local gatherer, the price to be received and therefore the return on investment increases. But for this you need to have standardized processes and qualified personnel, which will preferably be recruited in the same area of cultivation to promote economic development in the regionTesi

Application of Pulsed Electric Fields for Obtaining Antioxidant Extracts from Fish Residues

Fish processing has serious economic and environmental costs in the food supply chain. It is necessary to find new ways to convert fish residue to added-value products, especially for main aquaculture species. In this study, a pulsed electric field (PEF) process for antioxidant extract production from three residues (gills, bones, and heads) of two commercial species (sea bream and sea bass) was tested. Three methods of extraction using two solvents (water and methanol) and a water extraction assisted by PEF were assessed. Chemical and mineral compositions, as well as amino acid profile of the by-products, were determined. In addition, four in vitro antioxidant methods, 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH), 2,2-azinobis-(3-ethyl-benzothiazoline-6-sulphonate radical (ABTS), ferric reducing antioxidant power assay (FRAP), and oxygen radical absorbance capacity assay (ORAC), were used to evaluate the extracts. Antioxidant activity was confirmed by DPPH and ABTS and FRAP tests, obtaining the highest values for residues from the sea bream species. ORAC values were higher in methanol than in water solvent. In general, gills were the residues with the greatest antioxidant activity for the four antioxidant assays employed. For DPPH assay, the extracts of water assisted by PEF from heads, bones, and gills yielded significant increases of 35.8%, 68.6%, and 33.8% for sea bream and 60.7%, 71.8%, and 22.1% for sea bass, respectively, with respect to water extracts. Our results suggest that PEF would be an environmentally friendly and economic choice for antioxidant-extract production from low-value by-products from fish processingHis research received external funding by the EU Commission through the BBI-JU H2020 Project AQUABIOPRO-FIT “Aquaculture and agriculture biomass side stream proteins and bioactives for feed, fitness and health promoting nutritional supplements” (Grant Agreement no. 790956). Authors would like to acknowledge to GAIN (Axencia Galega de Innovación, Xunta de Galicia, Spain) for supporting this review (grant number IN607A2019/01). Paulo E.S. Munekata acknowledges postdoctoral fellowship support from the Ministry of Economy and Competitiveness (MINECO, Spain) “Juan de la Cierva” program (FJCI-2016-29486)S

DESARROLLO MODULAR DE UN MODELO GENÉRICO PARA LA DOMÓTICA MEDIANTE COMUNICACIÓN INALÁMBRICA BASADA EN EL PROTOCOLO ZIGBEE

ResumenEn este artículo se presenta el desarrollo y los resultados de un proyecto de investigación aplicada, vigente en el Departamento de Ingeniería Eléctrica y Electrónica del Instituto Tecnológico de Oaxaca.El proyecto consiste en integrar componentes de hardware y software para crear un sistema en domótica, que gestione los sensores y actuadores de manera inalámbrica mediante una red de equipos basados en el protocolo ZigBee perteneciente al grupo de Estándares del IEEE 802.15.4 en el área de redes inalámbricas personales(WPAN), utilizando la frecuencia de 2.4 GHz, en este se utilizan distintas herramientas tecnológicas para su implementación, digitalización, cuantificación, y transmisión; hasta llevar esos datos a un controlador que tiene la capacidad de generar el monitoreo y seguridad en nuestros hogares. El modelo de la arquitectura del proyecto corresponde a una topología estrella, en esta se establece el coordinador de la red, el cual con la instalación de sensores configurados con Arduino se manipularán con los dispositivos XBee, permitiendo así la creación de los circuitos y programación de los sensores.Palabras Claves: automatización, control, coordinador, monitoreo, señales. AbstractThis article describes the development and the results of a research project applied force at the Department of Electrical and Electronic Engineering Institute of Technology of Oaxaca.The project is to integrate hardware and software to create a system in home automation, which manages the sensors and actuators wirelessly through a network based on ZigBee protocol equipment belonging to the group of IEEE 802.15.4 standars in equipment wireless personal area networks (WPAN) using the 2.4 Ghz frequency in which various technological tools for implementation, digitization, quantification, and transmission are used; to bring that data to a controller that has the ability to generate monitoring and safety in our homes. The model of the project architecture corresponds to a star topology, where the network coordinator, which with installing configured with Arduino will be handled with XBee sensor devices is established, enabling the creation of circuits and programming sensors.Keywords: automation, control, coordinator, monitoring, signals

Stabilization of unstable reentrant atrial tachycardias via fractionated continuous electrical activity ablation (CHAOS study)

Background: Unstable reentrant atrial tachycardias (ATs) (i.e. those with frequent circuit modification or conversion to atrial fibrillation) are challenging to ablate. We tested a strategy to achieve arrhythmia stabilization into mappable stable ATs based on the detection and ablation of rotors. Methods: All consecutive patients from May 2017 to December 2019 were included. Mapping was performed using conventional high-density mapping catheters (IntellaMap ORION, PentaRay NAV or Advisor HD Grid). Rotors were subjectively identified as fractionated continuous (or quasi-continuous) electrograms on 1–2 adjacent bipoles, without dedicated software. In patients without detectable rotors, sites with spatiotemporal dispersion (i.e. all the cycle length comprised within the mapping catheter) plus non-continuous fractionation on single bipoles were targeted. Ablation success was defined as conversion to a stable AT or sinus rhythm. Results: Ninety seven patients with reentrant ATs were ablated. Of these, 18 (18.6%) presented unstable circuits. 13 (72%) patients had detectable rotors (median 2 [1–3] rotors per patient); focal ablation was successful in 12 (92%). In the other 5 patients, 17 sites with spatiotemporal dispersion were identified and targeted. Globally, and excluding 1 patient with spontaneous AT stabilization, ablation success was achieved in 16/17 patients (94.1%). One-year freedom from atrial arrhythmias was similar between patients with unstable and stable ATs (66.7% vs. 65.8%, p = 0.946). Conclusions: Most unstable reentrant ATs show detectable rotors, identified as sites with single-bipole fractionated quasi-continuous signals, or spatiotemporal dispersion plus non-continuous fractionation. Ablation of these sites is highly effective to stabilize the AT or convert it into sinus rhythm

Characterization of aerosol sources in León (Spain) using Positive Matrix Factorization and weather types

[EN] A one-year aerosol sampling campaign, between 2016 and 2017, was conducted in a suburban area of León city, Spain. An association between the Positive Matrix Factorization (PMF) results and air masses through circulation weather types was carried out, through the construction of linear models from the PM10 concentrations and its chemical composition. The aerosol sources, identified by PMF six-factor solution, were: traffic (29%), aged sea salt (26%), secondary aerosols (16%), dust (13%), marine aerosol (7%) and biomass burning (3%). Traffic and secondary factors showed the highest PM10 contribution in the hybrid cyclonic types with wind component from the first and second quadrant. Anticyclonic types with wind component from the first quadrant exhibited high values of secondary, aged sea salt and dust factors. The highest contributions of the dust factor were also associated with northerly types. The linear models built for estimating the source apportionment of PM10, from aerosol chemical composition and geostrophic flow, showed positive coefficients for: westerly flows (WF) in marine factor, southerly flows (SF) in secondary and traffic factors, and shear southerly vorticities (ZS) in dust factor. Negative dependences were observed for ZS in aged sea salt factor and for SF in dust factor. The PM10 mass concentration calculated by the linear models and by the PMF model were strongly correlated. This can be very useful to determine the contribution of a specific source to PM10 in León, only by knowing some meteorological and chemical variablesSIThis study was partially supported by the Spanish Ministry of Economy and Competitiveness (Grant TEC2014-57821-R), the University of León (Programa Propio 2015/00054/001 and 2018/00203/001) and the AERORAIN project (Ministry of Economy and Competitiveness, Grant CGL2014-52556-R, co-financed with European FEDER funds). F. Oduber acknowledges the grant BES-2015-074473 from the Spanish Ministry of Economy and Competitiveness. C. Blanco-Alegre acknowledges the grant FPU16-05764 from the Spanish Ministry of Education, Culture and Sport. Thanks are also due for the financial support to CESAM (UIDB/50017/2020+UIDP/50017/2020), to FCT/MCTES through national funds, and the co-funding by the FEDER, within the PT2020 Partnership Agreement and Compete 202