Ryerson University

About: Ryerson University is a education organization based out in Toronto, Ontario, Canada. It is known for research contribution in the topics: Computer science & Population. The organization has 7671 authors who have published 20164 publications receiving 394976 citations. The organization is also known as: Ryerson Polytechnical Institute & Ryerson Institute of Technology.

A Novel Five-Level Voltage Source Inverter With Sinusoidal Pulse Width Modulator for Medium-Voltage Applications

Abstract: This paper proposes a new five-level voltage source inverter for medium-voltage high-power applications. The proposed inverter is based on the upgrade of a four-level nested neutral-point clamped converter. This inverter can operate over a wide range of voltages without the need for connecting power semiconductor in series, has high-quality output voltage and fewer components compared to other classic five-level topologies. The features and operation of the proposed converter are studied and a simple sinusoidal PWM scheme is developed to control and balance the flying capacitors to their desired values. The performance of the proposed converter is evaluated by simulation and experimental results.

Urban Governance for Food Security: The Alternative Food System in Belo Horizonte, Brazil

Abstract: With a population of 2.5 million people, the city of Belo Horizonte, Brazil, is a world pioneer in tackling food consumption, distribution and production as components of an integrated urban policy for food security. The paper gives a description of the main programmes and features of this policy arguing that over 15 years the city and its Municipal Secretariat for Food Policy and Supply have built a particular alternative food system. Marked by the comprehensive scope of its programmes; its urban/rural focus; the flexibility of the initiatives and, above all, by its commitment to social justice and equitable access to food, Belo Horizonte has developed a distinct mode of governance for food security. The unique ‘alterity’ of this food system is set further apart from those being attempted in Europe and in North America because it is government-driven. The paper discusses its strengths and current challenges.

Perceived Ethnic Discrimination and Social Exclusion: Newcomer Immigrant Children in Canada

Abstract: This article examines relationships between perceived ethnic discrimination, social exclusion, psychosocial functioning, and academic performance among newcomer immigrant children from the People’s Republic of China, Hong Kong, and the Philippines using a subsample from the New Canadian Children and Youth Study of children aged 11–13 years (1,053) living in Montreal, Toronto, Vancouver, and the Prairies. Bivariate analysis showed that 25% of children reported being treated unfairly by peers and 14% by teachers because of who they are. Regression analyses revealed that perceived ethnic discrimination by peers and teachers was negatively related to children’s sense of social competence in peer relationships. Children’s self-esteem and sense of academic competence were negatively related to perceived discrimination by teachers. One in 5 children reported feeling like an outsider, with boys revealing higher levels of psychological isolation than girls. More than 1 in 10 were socially isolated and reported never participating in organized activities. This may reflect economic exclusion, as over one third of respondents belonged to families living below the Canadian Income Adequacy Measure. Psychological isolation, social isolation, and economic exclusion were significant predictors of children’s sense of academic competence and actual academic grades. Variations exist across age, sex, ethnicity, family structure, parental education, region of settlement, and length of time since arrival in Canada.

Model Predictive Current Control of Two-Level Four-Leg Inverters—Part II: Experimental Implementation and Validation

Abstract: This paper describes the experimental implementation of the model predictive current control algorithm for a two-level four-leg inverter operating under balanced, unbalanced, and nonlinear loading conditions. The proposed scheme is designed to predict the future behavior of the load currents for each of the 16 possible switching states of the converter. The control method chooses a switching state that minimizes the error between the output currents and their references. The algorithm is embedded using a MATLAB/Simulink software environment, and experimental results based on the dSPACE DS1103 controller are provided. These results verify the advantages of the proposed control strategy in terms of robustness under filter and load parameter variations, average neutral-leg switching frequency reduction, reference tracking error, and percentage total harmonic distortion.