Set-based approach to passenger aircraft family design

Presented is a method for the design of passenger aircraft families. Existing point-based methods found in the literature employ sequential approaches in which a single design solution is selected early and is then iteratively modified until all requirements are satisfied. The challenge with such approaches is that the design is driven toward a solution that, although promising to the optimizer, may be infeasible due to factors not considered by the models. The proposed method generates multiple solutions at the outset. Then, the infeasible solutions are discarded gradually through constraint satisfaction and set intersection. The method has been evaluated through a notional example of a three-member aircraft family design. The conclusion is that point-based design is still seen as preferable for incremental (conventional) designs based on a wealth of validated empirical methods, whereas the proposed approach, although resource-intensive, is seen as more suited to innovative designs

A manufacturing model to support data-driven applications for design and manufacture

This thesis is primarily concerned with conceptual work on the Manufacturing Model. The Manufacturing Model is an information model which describes the manufacturing capability of an enterprise. To achieve general applicability, the model consists of the entities that are relevant and important for any type of manufacturing firm, namely: manufacturing resources (e.g. machines, tools, fixtures, machining cells, operators, etc.), manufacturing processes (e.g. injection moulding, machining processes, etc.) and manufacturing strategies (e.g. how these resources and processes are used and organized). The Manufacturing Model is a four level model based on a de—facto standard (i.e. Factory, Shop, Cell, Station) which represents the functionality of the manufacturing facility of any firm. In the course of the research, the concept of data—driven applications has emerged in response to the need of integrated and flexible computer environments for the support of design and manufacturing activities. These data—driven applications require the use of different information models to capture and represent the company's information and knowledge. One of these information models is the Manufacturing Model. The value of this research work is highlighted by the use of two case studies, one related with the representation of a single machining station, and the other, the representation of a multi-cellular manufacturing facility of a high performance company

Optimization of Fuzzy Logic Controllers by Particle Swarm Optimization to Increase the Lifetime in Power Electronic Stages

In recent years, brushless direct current motor (BLDCM) applications have been increased due to their advantages as low size, mechanical torque, high-speed range, to mention some. The BLDCM control is required to operate at high frequency, high temperature, large voltage, and quick changes of current; as a result of this kind of operation, the power drive lifetime is affected. The power drives commonly utilized insulated gate bipolar transistors (IGBTs) and metal oxide semiconductor field effect transistors (MOSFETs), which present power losses, on-state losses, and switching losses caused by temperature oscillations. Hence, the power losses are related to the command signals generated by the controller. In this sense, the BLDC motor drive controller design, frequently, does not take into account the power losses and the temperature oscillations, which cause the IGBT lifetime decrease or premature fail. In this chapter, a brushless DC motor drive is designed based on a fuzzy controller tuned with the particle swarm optimization algorithm, where the temperature oscillations and speed set points are considered in order to increase IGBT module lifetime. The validation of the proposed fuzzy-PSO controller is carried out by the co-simulation between LabVIEW™ and Multisim™ and finally analysis and conclusion of the work

An integrated model of social media brand engagement

Despite the increasing use of social media sites to engage consumers, the consumer brand engagement construct is still in its infancy. This study aims to contribute to existing social media research by proposing and empirically testing a model in which social media brand involvement and social media brand communication are the main precursors and brand relationship quality is a relevant outcome of social media brand engagement. The findings show that the influence of social media brand involvement on social media brand engagement is stronger than the influence of social media brand communication. The latter is due to the co-creation of users and firms. Furthermore, interaction and attention are the most relevant components of social media brand engagement, followed by enthusiasm, identification, and absorption. Social media brand engagement is a useful tool for companies to gain competitive advantages. Thus, the findings could help firms better manage their social media tools in the context of social media communication

Artificial Hydrocarbon Networks Fuzzy Inference System

This paper presents a novel fuzzy inference model based on artificial hydrocarbon networks, a computational algorithm for modeling problems based on chemical hydrocarbon compounds. In particular, the proposed fuzzy-molecular inference model (FIM-model) uses molecular units of information to partition the output space in the defuzzification step. Moreover, these molecules are linguistic units that can be partially understandable due to the organized structure of the topology and metadata parameters involved in artificial hydrocarbon networks. In addition, a position controller for a direct current (DC) motor was implemented using the proposed FIM-model in type-1 and type-2 fuzzy inference systems. Experimental results demonstrate that the fuzzy-molecular inference model can be applied as an alternative of type-2 Mamdani’s fuzzy control systems because the set of molecular units can deal with dynamic uncertainties mostly present in real-world control applications

Inestabilidad institucional, evidencia para Colombia: la violencia y el crecimiento económico en el periodo 1950-2010.

La incertidumbre bajo periodos de inestabilidad institucional, traducida en violencia, puede destruir las dotaciones de capital físico y humano de la economía y, desestimular la inversión. En este trabajo se analiza el impacto de largo plazo de la violencia en el crecimiento económico de Colombia, en el período 1950-2010. La evidencia econométrica apoya la existencia de una relación negativa entre la violencia, medida por la tasa de homicidios, y el crecimiento económico. Los resultados sugieren que se debe realizar un esfuerzo institucional concertado para mejorar la inversión en educación y seguridad con el fin de acelerar el crecimiento.The uncertainty in periods of institutional instability, reflected in violence, can destroy the endowments of physical and human capital in the economy and, discourage investment. The paper analyses the long-run impact of the violence on the Colombia’s economic growth, using annual time series data from 1950 to 2010. The negative relationship between violence, as measured by homicide rate, and economic growth is supported econometrically. The findings have a strong implication on educational and security policies in Colombia. The results suggest that it must make a concerted effort to improve institutional investment in education and safety in order to accelerate growth

Selected abstracts of “Bioinformatics: from Algorithms to Applications 2020” conference

El documento solamente contiene el resumen de la ponenciaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Centro de Investigación en Enfermedades Tropicales (CIET)UCR::Vicerrectoría de Docencia::Salud::Facultad de Microbiologí

A case study of urban wastewater reclamation in Spain: comparison of water quality produced by using alternative processes and related costs

In Spain, and particularly in the Valencia Region, the scarcity of water resources means that water resource exploitation must be optimized. In this light, reusing the large amounts of treated wastewater is a top priority, especially in agriculture, urban use and the irrigation of golf courses. Rincón de León wastewater treatment plant–water reclamation plant (Alicante, Spain) supplies reclaimed flow to a number of users according to the guidelines stated in the Royal Decree 1620/2007. Reclamation treatment includes: coagulation + flocculation + filtration (sand bed), ultrafiltration, ultraviolet disinfection and desalination (reverse osmosis). By combining these processes, three tertiary treatment alternatives were configured, and for each of them the quality of effluents, treatment costs, energy consumption and the uses of treated water were analysed. The results show that the quality of the water treated using the three alternatives is suitable for different uses. Moreover, the costs resulting from the tertiary treatment processes, their energy consumption and the final price of the treated water paid by farmers have been obtained.This study was partially financed by the Ministry of Education via the projects ‘Treatment of superficial water and wastewater by membrane technologies to obtain high quality effluents' (CTM2010-15348) and ‘Treatment and wastewater reuse for a sustainable management’ (CONSOLIDER) (CSD200644), as well as by the Ministry of Science and Innovation via the project ‘Quality of Aquifers and agricultural impacts' (DER2011-27765), and the Council for Education, Formation and Occupation of the Government of Valencia (ACOMP 2012/136)