Creating A Cause For Sustainability: A Practice-Based Research Project For Undergraduate Students

Corporate social responsibility (CSR) and corporate sustainability (CS) practices have an influence on the image and profitability of any business. As business schools attempt to mold future leaders, schools have found exploring the topic of CSR and CS into their business curriculum. While many theoretical approaches have been taken, there are few examples of practical projects that professors can utilize in the classroom. Here, the authors present an example of a semester-long project that forces students to examine and reflect upon their own personal consumption habits and create a personal CSR report. The authors describe the project, expected outcomes, and the narratives that are created in the project and the course. Finally, the paper examines the importance of personal reflection on the development of personal cause and responsibility, which can help to develop future socially responsible leaders

Improvement in dc-link utilization with reduced current and torque deterioration for five-phase drives by combination of circulating-current filters and simple carrier-based PWM based on closed-form expressions

Multiphase drives offer important advantages over three-phase ones. With pulsewidth modulation (PWM), zero-sequence and x-y signals can be injected to enhance dc-link utilization (DLU). For example, in five-phase drives, for given dc-link voltage, the fundamental is raised by 23.1%. For sinusoidally distributed windings, although x-y currents increase losses, torque is unaffected. However, no simple carrier-based PWM methods based on closed-form expressions have been presented for this purpose so far. Most importantly, x-y currents may be unacceptably large, due to the small x-y impedance. This is particularly troublesome when high fundamental voltage is needed continuously. Applying square waveform instead of PWM raises the fundamental from 23.1 to 27.3%. Given the square-voltage distortion, filters with large x-y impedance were devised for this approach. However, some square-waveform harmonics map into the torque-producing plane without attenuation, generating torque ripple. This article proposes to use a simple carrier-based PWM method in five-phase drives combined with a circulating-current filter. The x-y voltages, which see large filter impedance, are exploited to achieve a high DLU similar to previous solutions, but without torque ripple or excessive x-y currents. Guidelines are given for designing the filter when used with the presented PWM strategy. Experimental results verify the proposalAgencia Estatal de Investigación | Ref. RYC2018-024407-IAgencia Estatal de Investigación | Ref. DPI2016-75832-

Strategy with smooth transitions and improved torque–speed region and stator copper loss for two-level asymmetrical six-phase induction motor drives under switch faults

Asymmetrical six-phase drives are very attractive to obtain fault tolerance. Most faults arise in the power electronics. Two conventional methods to handle switch/diode faults in two-level converters are keeping the corresponding phases open (in two-level multiphase drives) or connecting them to the dc-link midpoint (in two-level three-phase drives) through a bidirectional switch (e.g., triac/relay). However, the former yields larger stator copper loss (SCL) for given torque and smaller maximum torque, because of current constraints; on the other hand, the latter reduces the maximum speed, due to voltage constraints, and has not been considered for two-level multiphase drives. This article presents several proposals to improve fault-tolerant behavior in two-level asymmetrical six-phase induction motor drives. First, to adequately combine and alternate said two approaches in these particular drives, depending on the speed, neutral-point configuration, and faulty legs. In this manner, the SCL-per-torque decreases and the total torque-speed region of the drive is extended, i.e., the maximum torque and maximum speed rise compared with each of the aforementioned conventional strategies. Second, to also turn on/off a switch between stator neutral points for further improvement in this regard. Third, a pulsewidth modulation procedure to ensure smooth transitions between drive configurations. Experimental results confirm the theory.Agencia Estatal de Investigación | Ref. RYC2018-024407-

LyS at TASS 2015: Deep Learning Experiments for Sentiment Analysis on Spanish Tweets

[Abstract]: This paper describes the participation of the LyS group at tass 2015. In this year’s edition, we used a long short-term memory neural network to address the two proposed challenges: (1) sentiment analysis at a global level and (2) aspect-based sentiment analysis on football and political tweets. The performance of this deep learning approach is compared to our last-year model, based on a square-regularized logistic regression. Experimental results show that strategies such as unsupervised pre-training, sentiment-specific word embedding or modifying the current architec- ture might be needed to achieve state-of-the-art results.[Resumen]: Este art´ıculo describe la participaci´on del grupo LyS en el tass 2015. En la edici´on de este a˜no, hemos utilizado una red neuronal denominada long short- term memory para abordar los dos retos propuestos: (1) an´alisis del sentimiento a nivel global y (2) an´alisis del sentimiento a nivel de aspectos sobre tuits futbol´ısticos y de pol´ıtica. El rendimiento obtenido por esta red de aprendizaje profundo es comparado con el de nuestro sistema del a˜no pasado, una regresi´on log´ıstica con una regularizaci´on cuadr´atica. Los resultados experimentales muestran que es necesario incluir estrategias como pre-entrenamiento no supervisado, t´ecnicas espec´ıficas para representar palabras como vectores o modificar la arquitectura actual para alcanzar resultados acordes con el estado del arte.This research is supported by the Ministerio de Economía y Competitividad y FEDER (FFI2014-51978-C2) and Xunta de Galicia (R2014/034). The first author is funded by the Ministerio de Educación, Cultura y Deporte (FPU13/01180).Xunta de Galicia; R2014/03

Analysis of Undergraduate Dermatology Syllabi at Spanish Universities: Does the Weight of Theoretical Content Match the Skin Conditions Seen in Primary Care and General Dermatology Practices?

Introduction: Undergraduate dermatology courses vary in the nearly 50 Spanish medical faculties that teach the subject. This study aimed to describe the characteristics of these courses and to analyze whether the weight assigned to dermatology topics reflects the caseloads of primary care physicians and general dermatologists in the Spanish national health system. Material and methods: Cross-sectional study of syllabi used in Spanish medical faculties during the 2021---2022 academic year. We determined the number of teaching hours in public and private university curricula and compared the weight of dermatology topics covered to the dermatology caseloads of primary care physicians and general dermatologists as reported in published studies. Results: Most medical faculties taught dermatology for one semester. The median number of credits offered was 4.5. On average, lectures covered 24 theoretical topics, and seminars and workshops covered 9 topics. We identified a clear disparity between the percentage of time devoted to dermatology topics in course lectures and the skin conditions usually managed in primary care and general dermatology practices

Comparison of stator winding connections in multiphase drives under healthy operation and with one open converter leg

Multiphase machines with symmetrical windings offer various stator winding configurations (SWCs). It is known that, for a given five-phase machine, the pentagon SWC implies, compared with star, smaller voltage rating and greater current rating of the converter. For healthy conditions, the stator copper loss (SCL) and maximum achievable torque (MAT) are almost identical for both SWCs, provided such converter-rating adjustments and negligible circulating currents. Regarding the operation of five-phase machines under open converter leg (especially common fault), the pentagon SWC attains lower SCL (for given torque) and larger MAT than star. However, it is unknown if these characteristics hold (and to which extent) for other phase numbers and SWCs. This study compares for multiple phase numbers the SWCs in terms of converter rating, MAT and SCL, under healthy operation and with an open converter leg. Most importantly, it is shown that, for phase numbers higher than five (the case previously studied), the improvement in performance (especially postfault MAT) by resorting to SWCs other than star can be much larger than for five phases, and it is thus of considerable interest. The most convenient alternatives (often different from the five-phase case) are established. Experimental results with two multiphase drives are included