Incorporation of form deviations into the matrix transformation method for tolerance analysis in assemblies

Comunicación presentada a MESIC 2019 8th Manufacturing Engineering Society International Conference (Madrid, 19-21 de Junio de 2019)Mathematical models for tolerance representation are used to assess how the geometrical variation of a specific component feature propagates along the assembly, so that tolerance analysis in assemblies can be carried out using a specific tolerance propagation method. Several methods for tolerance analysis have been proposed in the literature, being some of them implemented in CAD systems. All these methods require modelling the geometrical variations of the component surfaces: parametric models, variational models, DoF models, etc. One of the most commonly used models is the DoF model, which is employed in a number of tolerance analysis methods: Small Displacement Torsor (SDT), Technologically and Topologically Related Surfaces (TTRS), Matrix Transformation, Unified Jacobian–Torsor model. However, none of the DoF-based tolerance analysis methods incorporates the effect of form deviations. Among the non DoF-based methods, there are two that include form tolerances: the Vector Loop or Kinematic method and the Tolerance Map (T-Map) model, although the latter is still under development. In this work, a proposal to incorporate form deviations into the matrix transformation method for tolerance analysis in assemblies is developed using a geometrical variation model based on the DoF model. The proposal is evaluated applying it to a 2D case study with components that only have flat surfaces, but the proposal can be extrapolated to 3D cases

PRODUCT DESIGN, DEVELOPMENT AND VIABILITY ANALYSIS MOTORCYCLE HELMET. LIGHT SECURITY SYSTEM “DragonFlight”

Every single one of us have heard ones or know someone who have had a bad experience with a motorbike, maybe it was his or her fault, perhaps it was originated due to the mistake of other vehicle or just was a simple distraction that caused as a result that small fright or that horrible accident. All the people who ride motorcycles assume that when an impact comes, our body is the chassis, our own body is in jeopardy to the unexpected just protected with a helmet and some protection clothes. The main goal of this project will be to try to reduce the possibilities of motorcycle users of having a fatality accident or at least reduce the gravity of them. We are going to create and develop a device to install in our helmets that turn on lights if the helmet and obviously “the biker” is decelerating. We will set up an emergency system as well in cases when the biker falls when we’ll show up as much lights as possible. The number of lights and as a result the intensity of the view are going to increase with the percentage of deceleration, this means that if the biker do an small deceleration we are just going to show a little light up however if the biker do a huge deceleration we will show an alarming and easy to see light in our helmet reducing then the perception and reaction time of the vehicles behind us. Our objective is to create a portable dispositive to be able to use it in more than one helmet so you as biker only have to buy one for all your helmets or to share with your family and friends

Algoritmos para el problema de Flujo Máximo

En el presente trabajo se introduce la teoría y herramientas correspondientes para presentar el algoritmo de Ford y Fulkerson y el algoritmo de preflujo. También se muestra un pequeño ejemplo para cada tipo de algoritmo en el que se puede observar ambos procedimientos.Posteriormente se realiza un estudio experimental para comparar los tiempos de ejecución de ambos algoritmos y se presentan las tablas y gráficas de tiempo correspondientes. <br /

Towards Data-driven Software-defined Infrastructures

Abstract The abundance of computing technologies and devices imply that we will live in a data-driven society in the next years. But this data-driven society requires radically new technologies in the data center to deal with data manipulation, transformation, access control, sharing and placement, among others. We advocate in this paper for a new generation of Software Defined Data Management Infrastructures covering the entire life- cycle of data. On the one hand, this will require new extensible programming abstractions and services for data-management in the data center. On the other hand, this also implies opening up the control plane to data owners outside the data center to manage the data life cycle. We present in this article the open challenges existing in data-driven software defined infrastructures and a use case based on Software Defined Protection of data

Arritmias ventriculares en el reinfarto agudo de miocardio : comparación entre reinfarto a distancia y alrededor de la cicatriz antigua /

Consultable des del TDXTítol obtingut de la portada digitalitzadaIntroducción: El miocardio alrededor de una cicatriz de infarto experimenta alteraciones a nivel electrofisiológico y neuro-autonómico que pueden interactuar con un nuevo episodio isquémico para generar arritmias. De este modo, una isquemia periinfarto puede llegar a ser más arritmogénica que una isquemia a distancia de la zona del infarto, pero este hecho es desconocido. Métodos: El estudio se realizó en 42 animales de experimentación (cerdos) con un infarto de miocardio de 1 mes de antigüedad que se provocó con una ligadura permanente de la arteria descendente anterior distal. Posteriormente se llevó a cabo una reoclusión coronaria a nivel de la arteria descendente anterior proximal (grupo I: isquemia periinfarto, n=21), o bien a nivel de la arteria circunfleja (grupo II: isquemia a distancia, n=21). Se analizaron las arritmias ventriculares durante 60 minutos tras la reoclusión y durante estimulación eléctrica programada. Se midió el tamaño del infarto, y la hipoperfusión del área ocluida fue estimada registrando la actividad de 99mTc-tetrofosmín. Resultados: El peso del área de isquemia aguda (23±9 versus 21±9 g), del área de necrosis (10±6 versus 10±3 g), la presión arterial sistólica, la frecuencia cardiaca, la presión basal ventricular izquierda, el pico dP/dt y la actividad del radiotrazador en el área ocluida (3±2% versus 5±2% de tejido normal) fueron comparables entre los dos grupos. El grupo I (isquemia periinfarto) presentó más extrasístoles ventriculares (mediana 136 versus 59, p=0.008), mayor incidencia de TV sostenida espontánea (57% versus 19%, p=0.02) y de FV espontánea (76% versus 47%, p=0.05), y más inducibilidad eléctrica de TV sostenida (65% versus 28%, p=0.03), pero una inducción eléctrica similar de FV, comparado con el grupo II (isquemia a distancia). Conclusiones: 1) La isquemia aguda periinfarto en el modelo porcino es más arritmogénica que la isquemia aguda a distancia de un infarto antiguo. 2) El distinto patrón arritmogénico de los dos grupos experimentales no se explica por diferencias en los parámetros hemodinámicos, en la extensión del área isquémica o en el flujo colateral.Background The myocardium bordering a healed infarction undergoes electrophysiological and autonomic neural derangements that may interact with a new ischemic episode to promote arrhythmias. Therefore, peri-infarction ischemia may be more arrhythmogenic than ischemia at a distance from the infarct zone, but this is not known. Methods Forty-two anesthetized open-chest pigs with a 1-month-old myocardial infarction induced by permanent ligature of the distal left anterior descending coronary artery (LAD) uderwen: a coronary reocclusion at either the proximal LAD (group 1, peri-infarction ischemia, n=21) or at the circumflex coronary artery (group 2, ischemia at a distance, n=21). Ventricular arrhythmias were analysed during 60 minutes of coronary reocclusion and during programmed electrical stimulation. Infarct size was measured, and underperfusion at the occluded area was estimated by recording 99m-Tc-tetrofosmin activity. Results Weights of acute ischemic (23±9 versus 21±9 g) and healed infarction (10±6 versus 10±3 g), baseline LV pressure and peak of LV dP/dt, and radiotracer activity at the occluded area (3±2% versus 5±2 % of normal tissue) were comparable between the two groups. Compared with group 2, group 1 showed more ventricular premature beats (median, 136 versus 59; p=0.008), a higher incidence of spontaneous sustained ventricular tachycardia (57% versus 19%, p=0.02) and ventricular fibrillation (76% versus 47%, p=0.05), and greater electrical inducibility of sustained ventricular tachycardia (65% versus 28%, p=0.03), but comparable induction of ventricular fibrillation. Conclusions Ischemia superimposed at the border of a 1-month-old myocardial infarction is more arrythmogenic than ischemia at a distance from the infarction zone in swine. Data suggest the presence of electrophysiological instability at the peri-infarction zone

Causes of damage to industrial brick masonry chimneys

[EN] From the early 19th to the middle of the 20th century, brick chimneys formed part of the industrial landscape. As technology advanced, factories were abandoned and became absorbed by the cities growing around them but masonry brick chimneys found a new role as part of the historical heritage. A large number of these structures are now protected buildings, which means they have to be maintained in a good state of conservation. Architects and engineers who have to assess the condition or retrofit these structures therefore need to be familiar with the different types of damage that can affect brickwork chimneys, and having access to a classification of the different types of damage they are prone to would be very useful to them. This paper classifies and describes the most common defects found in these structures, compiled after a close inspection of 538 Spanish industrial chimneys. The types of damage were classified according to: a) changes in the materials used in their construction, b) damage caused by repeated actions, c) damage due to extraordinary events, and d) damage caused by living organisms.López Patiño, MG.; Adam Martínez, JM.; Verdejo Gimeno, P.; Milani, G. (2017). Causes of damage to industrial brick masonry chimneys. Engineering Failure Analysis. 74:188-201. doi:10.1016/j.engfailanal.2017.01.014S1882017

Sulphite-free lamb burger meat: antimicrobial and antioxidant properties of green tea and carvacrol

BACKGROUND Sulfite is commonly used to preserve lamb burger meat in the EU. Nevertheless, its consumption has been related to certain health problems, which has increased consumer demand for sulfite-free products. Natural compounds with antioxidant and antimicrobial properties may be a feasible alternative to preserve lamb burger meat. This study evaluated the antimicrobial and antioxidant properties of carvacrol, green tea and their combination in preserving lamb burger meat. Their effect was also compared with that of 400¿ppm sulfite. RESULTS Lamb burger meat was mixed with different concentrations of the extracts, packaged aerobically and displayed for 8 days at 4 °C. Total polyphenols, thiobarbituric acid reactive substances, colour, and microbial and sensory analyses were performed. Both green tea and carvacrol avoided lipid oxidation even at 300¿ppm, while only carvacrol, which showed a concentration-dependent action, delayed discolouration and microbial growth. Carvacrol and green tea also limited the development of oxidation odour and flavour, but the former brought about herbal odours and flavours to the meat. On the other hand, sulfite provided a higher colour stability and lower microbial counts than both natural compounds but presented a higher lipid oxidation. CONCLUSION Carvacrol seems to be a promising alternative to replace sulfite in lamb burger meat, whereas green tea should be combined with an antimicrobial agent. © 2018 Society of Chemical Industr

Fault Modeling of Graphene Nanoribbon FET Logic Circuits

[EN] Due to the increasing defect rates in highly scaled complementary metal-oxide-semiconductor (CMOS) devices, and the emergence of alternative nanotechnology devices, reliability challenges are of growing importance. Understanding and controlling the fault mechanisms associated with new materials and structures for both transistors and interconnection is a key issue in novel nanodevices. The graphene nanoribbon field-effect transistor (GNR FET) has revealed itself as a promising technology to design emerging research logic circuits, because of its outstanding potential speed and power properties. This work presents a study of fault causes, mechanisms, and models at the device level, as well as their impact on logic circuits based on GNR FETs. From a literature review of fault causes and mechanisms, fault propagation was analyzed, and fault models were derived for device and logic circuit levels. This study may be helpful for the prevention of faults in the design process of graphene nanodevices. In addition, it can help in the design and evaluation of defect- and fault-tolerant nanoarchitectures based on graphene circuits. Results are compared with other emerging devices, such as carbon nanotube (CNT) FET and nanowire (NW) FET.This work was supported in part by the Spanish Government under the research project TIN2016-81075-R and by Primeros Proyectos de Investigacion (PAID-06-18), Vicerrectorado de Investigacion, Innovacion y Transferencia de la Universitat Politecnica de Valencia (UPV), under the project 200190032.Gil Tomás, DA.; Gracia-Morán, J.; Saiz-Adalid, L.; Gil, P. (2019). Fault Modeling of Graphene Nanoribbon FET Logic Circuits. Electronics. 8(8):1-18. https://doi.org/10.3390/electronics8080851S11888International Technology Roadmap for Semiconductors (ITRS) 2013http://www.itrs2.net/2013-itrs.htmlSchuegraf, K., Abraham, M. C., Brand, A., Naik, M., & Thakur, R. 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Scalable Electrical Compact Modeling for Graphene FET Transistors. IEEE Transactions on Nanotechnology, 12(4), 539-546. doi:10.1109/tnano.2013.2257832Chen, Y.-Y., Sangai, A., Rogachev, A., Gholipour, M., Iannaccone, G., Fiori, G., & Chen, D. (2015). A SPICE-Compatible Model of MOS-Type Graphene Nano-Ribbon Field-Effect Transistors Enabling Gate- and Circuit-Level Delay and Power Analysis Under Process Variation. IEEE Transactions on Nanotechnology, 14(6), 1068-1082. doi:10.1109/tnano.2015.2469647Ferrari, A. C., Bonaccorso, F., Fal’ko, V., Novoselov, K. S., Roche, S., Bøggild, P., … Pugno, N. (2015). Science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems. Nanoscale, 7(11), 4598-4810. doi:10.1039/c4nr01600aHong, A. J., Song, E. B., Yu, H. S., Allen, M. J., Kim, J., Fowler, J. D., … Wang, K. L. (2011). Graphene Flash Memory. ACS Nano, 5(10), 7812-7817. doi:10.1021/nn201809kJeng, S.-L., Lu, J.-C., & Wang, K. (2007). 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Improving Error Correction Codes for Multiple-Cell Upsets in Space Applications

© 2018 IEEE. Personal use of this material is permitted. Permissíon from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertisíng or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.[EN] Currently, faults suffered by SRAM memory systems have increased due to the aggressive CMOS integration density. Thus, the probability of occurrence of single-cell upsets (SCUs) or multiple-cell upsets (MCUs) augments. One of the main causes of MCUs in space applications is cosmic radiation. A common solution is the use of error correction codes (ECCs). Nevertheless, when using ECCs in space applications, they must achieve a good balance between error coverage and redundancy, and their encoding/decoding circuits must be efficient in terms of area, power, and delay. Different codes have been proposed to tolerate MCUs. For instance, Matrix codes use Hamming codes and parity checks in a bi-dimensional layout to correct and detect some patterns of MCUs. Recently presented, column¿line¿code (CLC) has been designed to tolerate MCUs in space applications. CLC is a modified Matrix code, based on extended Hamming codes and parity checks. Nevertheless, a common property of these codes is the high redundancy introduced. In this paper, we present a series of new lowredundant ECCs able to correct MCUs with reduced area, power, and delay overheads. Also, these new codes maintain, or even improve, memory error coverage with respect to Matrix and CLC codes.This work was supported by the Spanish Government under the research Project TIN2016-81075-R.Gracia-Morán, J.; Saiz-Adalid, L.; Gil Tomás, DA.; Gil, P. (2018). Improving Error Correction Codes for Multiple-Cell Upsets in Space Applications. IEEE Transactions on Very Large Scale Integration (VLSI) Systems. 26(10):2132-2142. https://doi.org/10.1109/TVLSI.2018.2837220S21322142261