A Political-Economy Theory of Trade Agreements

This paper presents a theory of trade agreements where "politics" play an central role. This stands in contrast with the standard theory, where even politically-motivated governments sign trade agreements only to deal with terms-of-trade externalities. We develop a model where governments may be motivated to sign a trade agreement both by the presence of standard terms-of-trade externalities and by the desire to commit vis-a-vis domestic industrial lobbies. The model is rich in implications. In particular, it predicts that trade agreements result in deeper trade liberalization when governments are more politically motivated (provided capital mobility is sufficiently high) and when capital can move more freely across sectors. Also, governments tend to prefer a commitment in the form of tariff ceilings rather than exact tariff levels. In a fully dynamic specification of the model, trade liberalization occurs in two stages: an immediate slashing of tariffs and a subsequent gradual reduction of tariffs. The immediate tariff cut is a reflection of the terms-of-trade motive for the agreement, while the domestic-commitment motive is reflected in the gradual phase of trade liberalization. Finally, the speed of trade liberalization is higher when capital is more mobile across sectors.

Study of the lateral pass width for conventional and ultrasonic vibrations-assisted ball burnishing on Ti-6Al-4V specimens

Ball burnishing is a technological finishing process based on plastic deformation of the objective surface by means of a hard ball gliding over it. Along with its easiness of application, possible on the same machine where machining was performed [1], burnishing is a comprehensive process able to achieve surface roughness improvements, and compressive residual stresses up to deep layers of the material [2]. Burnishing results have proved to be depending of a proper selection of parameters, which must be correctly controlled during the process. That is the case of burnishing force or the number of passes [3]. Among these parameters, the lateral pass width has proved to be influential on the surface roughness results, due to the behavior that most materials show when being plastically deformed. In effect, the applied force makes the material to flow to the borders of the burnishing imprint, giving way to a pile-up effect. This paper deals with indentation experiments on Ti-6Al-4V to deepen in the burnishing process of this material. Single burnishing imprints are geometrically characterized combining different levels of force, number of passes, and comparing the conventional process with that assisted with vibrations. An optimal lateral pass width is thus determined, and technological recommendations are made for future applications of the process.Peer ReviewedPostprint (author's final draft

Who's afraid of a globalized world? Foreign Direct Investments, local knowledge and allocation of talents

We study the distributional effects of globalization within a model of heterogeneous agents where both managerial talent and knowledge of the local economic environment are required in order to become a successful entrepreneur. Agents willing to set up a firm abroad incur a learning cost that depends on how different the foreign and domestic entrepreneurial environments are. In this context, we show that globalization fosters FDI and raises wages, output and productivity. However, not everybody wins. The steady state relationship between globalization and income is U-shaped: high- and low-income agents are better off in a globalized world, while middle-income agents (domestic entrepreneurs) are worse off. Thus, consistently with recent empirical evidence, the model predicts globalization to increase inequality at the top of the income distribution while decreasing it at the bottom

Enhancing Coexistence in the Unlicensed Band with Massive MIMO

We consider cellular base stations (BSs) equipped with a large number of antennas and operating in the unlicensed band. We denote such system as massive MIMO unlicensed (mMIMO-U). We design the key procedures required to guarantee coexistence between a cellular BS and nearby Wi-Fi devices. These include: neighboring Wi-Fi channel covariance estimation, allocation of spatial degrees of freedom for interference suppression, and enhanced channel sensing and data transmission phases. We evaluate the performance of the so-designed mMIMO-U, showing that it allows simultaneous cellular and Wi-Fi transmissions by keeping their mutual interference below the regulatory threshold. The same is not true for conventional listen-before-talk (LBT) operations. As a result, mMIMO-U boosts the aggregate cellular-plus-Wi-Fi data rate in the unlicensed band with respect to conventional LBT, exhibiting increasing gains as the number of BS antennas grows.Comment: To appear in Proc. IEEE ICC 201

Indoor Massive MIMO Deployments for Uniformly High Wireless Capacity

Providing consistently high wireless capacity is becoming increasingly important to support the applications required by future digital enterprises. In this paper, we propose Eigen-direction-aware ZF (EDA-ZF) with partial coordination among base stations (BSs) and distributed interference suppression as a practical approach to achieve this objective. We compare our solution with Zero Forcing (ZF), entailing neither BS coordination or inter-cell interference mitigation, and Network MIMO (NeMIMO), where full BS coordination enables centralized inter-cell interference management. We also evaluate the performance of said schemes for three sub-6 GHz deployments with varying BS densities -- sparse, intermediate, and dense -- all with fixed total number of antennas and radiated power. Extensive simulations show that: (i) indoor massive MIMO implementing the proposed EDA-ZF provides uniformly good rates for all users; (ii) indoor network densification is detrimental unless full coordination is implemented; (iii) deploying NeMIMO pays off under strong outdoor interference, especially for cell-edge users

Comparison of thermal performance of 3D printer liquefiers through finite element models

Open source 3D printers have experienced an intense expansion during the last years, mainly because of their accessibility and the vast availability of information thanks to user communities. This fact presents researchers with a perfect context for hardware innovation, by improving the overall printing process, also in terms of durability of the printing machine. A 3D printer liquefier must transmit heat to the thermoplastic material in order to extrude it, reaching temperatures above 200 degrees for some materials like ABS on the tip of the nozzle. The design of the heating process must comply with keeping the balance between proper heating of the material and controlling the temperature along the extruding body, so that the printer itself is not harmed for overtemperature. On the other hand, the design must guarantee that the melting front is located in an intermediate point between the nozzle tip and the entrance of the raw material, to minimize pressure drops in the system, and so decreasing the demanding energy to the feeding motors. An alternative design of the heating system, Twist3D, is proposed in this paper.Peer ReviewedPostprint (published version

Material Didático para as sessões de TANDEM: elaboração, aplicação e análise

VII Seminário de Extensão Universitária da UNILA (SEUNI); VIII Encontro de Iniciação Científica e IV Encontro de Iniciação em Desenvolvimento Tecnológico e Inovação (EICTI 2019) e Seminário de Atividades Formativas da UNILA (SAFOR)Com o propósito de possibilitar uma abordagem linguístico-cultural, o ​ Projeto TANDEM: aproximando línguas-culturas latino-americanas e caribenhas foi criado como parte integrante do ensino e aprendizagem de espanhol e português na Universidade Federal da Integração Latino-Americana (UNILA). A partir do ensino, pesquisa e extensão, o projeto desenvolve uma exaustiva exploração de materiais didáticos para promover o uso efetivo da língua estrangeira/adicional. A pesquisa teve como objetivo criar materiais didáticos com um enfoque na abordagem comunicativa e na gramática contrastiva, para encontros de tandem entre brasileiros aprendizes de espanhol e hispanofalantes aprendizes de português. A pesquisa foi orientada por três objetivos: a) Descrever o funcionamento do Tandem em relação à aprendizagem de Português e Espanhol; b) Averiguar a relevância de abordar aspectos gramaticais em materiais didáticos para a prática de Tandem; c) Analisar os materiais didáticos propostos, expondo os resultados da aplicação. Logo, tendo como norte os pressupostos da pesquisa-ação, é possível planejar, descrever, avaliar mudanças e promover melhorias. Assim, buscamos descrever os desafios de abordar a gramática de forma didática e da mesma forma monitorar e avaliar o processo de aprendizagem. Diante da falta de ferramentas ou métodos para aprimorar o ensino-aprendizagem da oralidade e da gramática, constatamos que as práticas de Tandem trazem resultados favoráveis para o desenvolvimento do conhecimento gramatical junto com o aperfeiçoamento de habilidades orais. Os resultados apontam que o uso da pesquisa-ação na elaboração, aplicação e análise das atividades mostrou-se adequado ao caso estudado. Os materiais desenvolvidos estimularam a participação dos estudantes melhorando seu nível de proficiência na língua-alvo, além de proporcionar reflexão crítica sobre questões gramaticais tanto na língua materna como na língua a ser aprendidaAgradecemos à UNILA e a Pró-Reitoria de Pesquisa e Pós-Graduação (PRPPG) pela concessão de bolsa que permitiu a realização da presente pesquis