Aggregation Problems in Estimates of Armington Elasticities and Pass-Through Effects

This article examines the level of aggregation problem for which Armington price elasticity of substitution and pass-through effects are usually estimated. On the basis of U.S. import data from 1995 to 2004 of wood products from Brazil and Mexico, it is argued that the usuallevels of aggregation used in the estimates for the elasticity of substitution are too high, since they tend to aggregate perfectly elastic products together with products whose elasticities vary from zero to any negative number. Analogously, the elasticity of relative prices with respect to the exchange rate, a measure of the pass-through effect, tends to be underestimated in the U.S. by the presence of homogeneous products whose prices are set in dollars and tend to equalize through arbitrage. Therefore, pricing-to-market estimates may be grossly overestimated for some industries in the U.S.Homogeneous Products, Differentiated Product, Pass-Through, Pricing-to-Market, Law of One Price

Reforma da Educação Superior Brasileira: Uma Contribuição ao Debate

Um dos grandes desafios da universidade, hoje, é estar em sintonia com os novos tempos. As tendências de futuro devem ser consideradas, para que a universidade seja capaz de responder às novas demandas, criando novos cursos, inventando novos processos pedagógicos e gerando conhecimentos. A vocação original da universidade, sua característica com uma das mais respeitáveis instituições sociais da sociedade moderna, bem como a trajetória institucional das reformas da educação superior no Brasil são fatores relevantes e indispensáveis para melhor compreensão da atual Reforma da Educação Superior proposta pelo Governo Federal e, ainda em processo de discussão com a comunidade universitária brasileira. Por último, a luz dos resultados de uma pesquisa mais ampla que envolveu dirigentes de uma instituição publica estadual de ensino superior, destila-se as principais recomendações oferecidas por esses informantes-chaves, visando suscitar o debate sobre os rumos da Educação Superior no Brasil

Darrieus vertical axis wind turbines: methodology to study the self-start capabilities considering symmetric and asymmetric airfoils

The rapid growth of wind power generation and the need for a smarter grid with decentralized energy generation has increased the interest in vertical axis wind turbines (VAWT), especially for the urban areas. For the urban areas the VAWT offer several advantages over the horizontal ones, so their acceptance is rising. The lift-type VAWT (Darrieus wind turbines) have a natural inability to self-start without the help of extra components. The existing methodologies are usually used to optimize the wind turbine performance, but not its ability to self-start. Indeed, studying the aerodynamic behavior of blade profiles is a very complex and time-consuming task, since blades move around the rotor axis in a three-dimensional aerodynamic environment. Hence, a new methodology is presented in this paper to study the self-start ability of VAWT, which offers a substantial time reduction in the first steps of new blade profiles development. Both symmetrical and asymmetrical airfoils are targeted in our study, presenting comprehensive results to validate our methodology

Large Geographical Area Aerial Surveillance Systems Data Network Infrastructure Managed by Artificial Intelligence and Certified Over Blockchain: a Review

This paper proposes an aerial data network infrastructure for large geographical area surveillance systems. The work presents a review of previous works from the authors, existing technologies in the market and other scientific work, with the goal of creating a data network supported by Autonomous Tethered Aerostat Airships used for sensor fixing, drones deployment base and meshed data network nodes installation. The proposed approach for data network infrastructure supports several independent and heterogeneous services from independent, private and public companies. The presented solution employs Edge Artificial Intelligence (AI) systems for autonomous infrastructure management. The Edge AI used in the presented solution enables the AI management solution to work without the need of a permanent connection to cloud services and is constantly feed by the locally generated sensor data. These systems interact with other network AI services to accomplish coordinated tasks. Blockchain technology services are deployed to ensure secure and auditable decisions and operations, validated by the different involved ledgers

Wireless technologies for Controlling a Traffic Lights Prototype

This paper presents a traffic light control system based on wireless communication technologies. Traffic density is increasing at an alarming rate in developing countries which calls for intelligent dynamic traffic light control systems to replace the conventional manual and time based ones. The approach followed in this paper is based in a secure wireless sensor network to feed real time data to the intelligent traffic light control. A physical prototype was implemented for experimental validation. The physical prototype showed robustness against local failures or unforeseen cases showing that the communication between modules keeps an acceptable packets received ratio

Upgrading a legacy manufacturing cell to IoT

Many industries, like aeronauting construction are still equipped with legacy machines and are not keen to change old, however fully functional, equipment to new ones. Hence, an upgrade must be found to cope the legacy and fully functional machines to IOT technologies. This paper is a contribution to embrace those challenges in a new IoT architecture able to support the creation of solutions for Smart Industries. Internet of Things is increasing acceptance and the infrastructure for them is becoming available. This leads to an insurgence on investments and development of new dedicated IoT infrastructures. Industries need to adapt quickly to this constant technological evolution, implementing measures and connecting machines and robots at critical points to the Internet, instrumenting them using the concept of IoT, with the major goal of implementing a flexible, secure, easy to maintain and capable to evolve infrastructure, when legacy equipment is involved. The availability of machines and other critical assets directly affects the effectiveness of manufacturing operations. The architecture design offers security, flexibility, simplicity of implementation and maintenance, and is resilient to failures or attacks and technologically independent. Field tests are reported to evaluate key aspects of the proposed architecture

Traffic Light Using Multiple Wireless Technologies

This paper presents the study and experimental tests for the viability analysis of using multiple wireless technologies in urban traffic light controllers in a Smart City environment. Communication drivers, different types of antennas, data acquisition methods and data processing for monitoring the network are presented. The sensors and actuators modules are connected in a local area network through two distinct low power wireless networks using both 868 MHz and 2.4 GHz frequency bands. All data communications using 868 MHz go through a Moteino. Various tests are made to assess the most advantageous features of each communication type. The experimental results show better range for 868 MHz solutions, whereas the 2.4 GHz presents the advantage of self-regenerating the network and mesh. The different pros and cons of both communication methods are presented

Wireless networks for traffic light control on urban and aerotropolis roads

This paper presents a traffic lights system based on wireless communication, providing a support infrastructure for intelligent control in smart cities and aerotropolis scope. An aerotropolis is a metropolitan subregion which infrastructure is centered around an airport [1]. Traffic intensity is increasing all over the world. Intelligent dynamic traffic lights system control are sought for replacing classic conventional manual and time based systems. In this work a wireless sensors network is designed and implemented to feed real time data to the intelligent traffic lights systems control. A physical prototype is implemented for experimental validation outside laboratory environment. The physical prototype shows robustness against unexpected issues or local failures. Results are positive in the scope of the experiences made and promising in terms of extending the tests to larger areas