E-government simulation tool for accounting education: personal income tax simulator

This chapter describes a simulator used by accounting students to mimic the official process of filling out a Personal Income Tax form. According to the Portuguese law, this form describes the amount of the employees’ Personal Income Tax withheld within a company, which must be submitted periodically to the Portuguese Tax Administration. This process is accomplished through an E-government tool accessed by only authorized company staff, which makes it impossible for accounting students to use it. This presents an obstacle for students who are learning about accounting because they cannot experiment with the “real” process in the courses they are studying. By using the proposed simulator that imitates the behavior and interface of the official tools, students can “learn by doing.

Modulation Methods for Direct and Indirect Matrix Converters: A Review

Matrix converters (MCs) allow the implementation of single-stage AC/AC power conversion systems (PCS) with inherent bidirectional power flow capability. By avoiding the typical DC-link capacitor, MCs have the potential to achieve higher power density with a more reliable operation and less maintenance when compared with conventional two-stage AC/DC/AC PCS. For these reasons, matrix converters have been receiving significant attention from the academic sector but have not yet been implemented on a large industrial scale. This article reviews the Direct Matrix Converter (DMC) and the Indirect Matrix Converter (IMC) along with the respective actual and most important modulation methods. Simulation results are provided to validate the theoretical analysis and to get a deep insight about the implementation of space vector modulation (SVM) and respective switching pattern generator

EMI Filter Design for a Single-stage Bidirectional and Isolated AC–DC Matrix Converter

This paper describes the design of an electromagnetic interference (EMI) filter for the high-frequency link matrix converter (HFLMC). The proposed method aims to systematize the design process for pre-compliance with CISPR 11 Class B standard in the frequency range 150 kHz to 30 MHz. This approach can be extended to other current source converters which allows time-savings during the project of the filter. Conducted emissions are estimated through extended simulation and take into account the effect of the measurement apparatus. Differential-mode (DM) and common-mode (CM) filtering stages are projected separately and then integrated in a synergistic way in a single PCB to reduce volume and weight. A prototype of the filter was constructed and tested in the laboratory. Experimental results with the characterization of the insertion losses following the CISPR 17 standard are provided. The attenuation capability of the filter was demonstrated in the final part of the paper

Anurofauna do noroeste paulista: lista de espécies e chave de identificação para adultos

A correta identificação de espécies normalmente é um obstáculo para estudos de conservação, manejo e licenciamento ambiental. Atualmente 37 espécies de cinco famílias de anfíbios anuros são registradas na área que abrange integralmente as Unidades de Gerenciamento dos Recursos Hídricos (UGRHIs) do Turvo-Grande e São José dos Dourados e parte das UGHRIs do Baixo Pardo, Baixo Tietê e Tietê-Batalha. Embora esta fauna venha sendo objeto de estudos quase ininterruptos desde a metade da década de 1960, nenhuma chave de identificação que incluísse todas as espécies reconhecidas na região estava disponível. Embora desenvolvida para uma anurofauna regional, esta chave tem ampla aplicação porque as espécies encontradas na área de abrangência do estudo são associadas à áreas abertas e apresentam ampla distribuição geográfica. Este estudo visa preencher esta lacuna e apresentar uma lista ilustrada e uma chave dicotômica artificial para as 37 espécies de anuros conhecidas para esta região.The correct identification of species is a common impediment for studies of conservation, management and environmental licensing. Currently, 37 species from five families of anuran amphibians are recorded in the region that includes the Turvo-Grande, São José dos Dourados and parts of the Low Pardo, Low Tietê and Tietê-Batalha Hydric Resources Management Unit (UGRHIs). Despite of being studied since de mid-1960's, none identification key that included all the species recognized was available. Although developed for a regional anuranfauna, this key has wide application because the species found in the studied region are associated to open areas and have wide geographical distribution. This study aims to fill this gap presenting an illustrated list about species' biology, and a dichotomous key that comprises 37 anuran species.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq