Adaptive SMC based on the dynamic containment of the sliding variable

Conventional Sliding Mode Controllers (SMCs) exhibit a robust performance against matched bounded uncertainties and disturbances by containing them under a fixed controller’s effort. Consequently, the controller is commonly found excessive, leading to chattering and straining the actuator. As a solution, the variable-gain SMCs adapt to the instantaneous system requirements, thus attenuating the aforesaid effects and keeping the SMC’s benefits. However, the reported adaptive laws underlying such behavior commonly require arbitrary design considerations and do not consider practical implementation. Unlikely, in this work, a hysteresis-based adaptability law to drive the sliding variable to a boundary layer around zero is proposed. The sliding boundary—hysteresis’ width—will consistently “bounce” over the sliding variable, trying to shrink against it while preserving the sliding mode. This behavior finds its steady-state once the sliding variable and the sliding boundary’s dynamics are synchronized, with no need of subjective or arbitrary adjustments. The close-loop tuning can be derived from the system’s parameters alone, and its steady-state performance can be quantitatively predicted. Furthermore, a method to adjust the sliding surface parameters according to the system’s desired behavior is provided, all in a closed, analytical way. Finally, the physical actuator limits are taken into account and never exceeded, and the discrete nature of the devices normally used for SMC implementation is incorporated throughout. Two examples are studied to portray the proposal’s advantages.     

Promoting communication skills for information systems students in Australian and Portuguese higher education: Action research study

This paper aims to examine the value of communication skills learning process through various assessments in Information Systems (IS) postgraduate units in Australia and Portugal. Currently, communication skills are indispensable to students in expanding their social networks and their knowledge at university and in the future workplace, since businesses expect their employees to have strong communication and presentation skills. This paper provides empirical evidence based on the anonymous quantitative and qualitative data collected during 2 years from 126 postgraduate students, which were collected via formal and informal feedback. Various assessment methods were used in Information Systems units to promote and develop the communication skills; these assessments are: reflective journal, business plan and prototype, discussion forum, presentation, and final examination. A Communication skills model (CSM) was developed based on Action research principles to promote the assessments which will assist IS students to enhance their communication skills. The research outcomes indicated that integrating communication skills in the assessments will allow students to promote their communication skills and boost their self-esteem skills. Furthermore, this paper added a new theoretical and practical contribution to higher-education teaching and learning literature, especially the action research for teachers to promote and develop communication skills among students. Finally, integrating these skills in the units should meet the objectives and aims of the units, Master’s degrees, universities, and businesses’ needs, and satisfy our student’s needs.     

The impact of a Curriculum for Resilience Promotion in Deaf Children and Adolescents

Resilience is an interactive process involving internal skills that should be promoted, especially in the early stages of development. This study aims to adapt and implement two themes from the European Curriculum for Resilience Promotion – RESCUR, namely, ‘Developing Communication Skills’ and ‘Establishing and Maintaining Healthy Relationships’, for deaf and hard-of-hearing (DHH) students. The study included 37 children and adolescents from three Portuguese regions and its impact was evaluated through the perspectives of the students, their guardians and their teachers. Each 90-minute session was implemented weekly. The sessions followed the RESCUR curriculum structure with necessary adaptations to the mindfulness activities, stories, role-play and worksheets. The mean scores increased from pre- to post-intervention assessment on all instruments, namely, KIDSCREEN-10 (children/adolescents), KIDSCREEN-10 (guardians) and CYRM-28 (teachers). The implementation of adapted curricula promoting resilience seems to be beneficial to DHH children, allowing the development of specific resilience-associated skills, and thus enhancing health, well-being and quality of life.     

Waiting for the Tide to Change? Strategies for Survival of Portuguese Private HEIs

The topic of declining private higher education (PHE) has become a timely one, especially for many countries that had previously experienced a rapid and massive expansion of their systems of higher education, and of PHE in particular. In the case of Portugal this was very likely due to the stabilisation and then the slight decline in the number of applicants and the steady expansion of the public system Thus, the Portuguese system has become an interesting case study of the several types of strategies that may be adopted by PHE institutions when facing a declining student demand.     

Application of the Rasch model to measuring the impact of scientific journals

This paper focuses on a fresh and fair way to determine a ranking of science journals according to the “number of citations-to and articles published,” data used by SCI Journal Citation Reports of ISI to determine journal ranking by “impact factor.” Impact is considered a latent variable defined by a set of items (citations and articles published). The theoretical background is Item Response Theory, which suggests that, if we can understand how each item in a set of items operates with an object, then we can estimate a measure for the object. The Rasch model is the most common formulation of that theory. This technique is here applied to the citations and articles published of 62 medical journals (objects) to provide a Rasch measure for these journals which is compared with the current “impact factor” computation.     

Analyzing false memories in children with associative lists specific for their age

Two experiments attempted to resolve previous contradictory findings concerning developmental trends in false memories within the Deese-Roediger-McDermott (DRM) paradigm by using an improved methodology--constructing age-appropriate associative lists. The research also extended the DRM paradigm to preschoolers. Experiment 1 (N=320) included children in three age groups (preschoolers of 3-4 years, second-graders of 7-8 years, and preadolescents of 11-12 years) and adults, and Experiment 2 (N=64) examined preschoolers and preadolescents. Age-appropriate lists increased false recall. Although preschoolers had fewer false memories than the other age groups, they showed considerable levels of false recall when tested with age-appropriate materials. Results were discussed in terms of fuzzy-trace, source-monitoring, and activation frameworks.     

A sense of place in the science classroom

Place‐based science education engages with the laboratories of complex reality where natural processes combine with social practice, going beyond the physical world, to encompass the meanings and sense of attachment local residents feel for places. This brief report describes how a university science methods class in a primary teacher training programme situated scientific understandings in the rich cultural context of the historically rural and socio‐economically disadvantaged area of Galicia in north‐western Spain, where agrarian traditions continue to influence local culture. Focusing on student responses to two assignments, this brief report explores how the preparation of lesson plans related to food and environmental investigation projects served to integrate aspects of the natural, social and cultural environment to foster a critical pedagogy of place.     

Regulation as both enabler of technology use and global competitive tool: The Gibraltar case

Distributed ledger technologies (DLTs) such as Blockchain appear to have disruptive economic potential to traditional finance-sector and non-financial markets as the success of crypto currencies demonstrates. While traditional financial and securities markets are highly regulated, DLT transactions and exchanges have so far widely remained unregulated, which potentially poses major threats to individual investors and, via money laundering, terrorist financing, and tax evasion, to society at large. Governments have been taking different approaches to monitoring and regulating the fledgling DLT provision arena. However, the small jurisdiction of Gibraltar, an affluent self-governed and self-financed British overseas territory with a population of 34,000 at the Southern tip of the Iberian Peninsula has taken a proactive approach. What makes this case stand out is that Gibraltar is not only is the first jurisdiction worldwide to regulate general DLT provision, but it is rather using the regulation as a competitive tool and a means for creating new public value. The study inquires the potential benefits and challenges to this particular approach to DLT provision regulation, and it investigates and presents the various facets of public value generation, which might serve as a poster child for fast and smart regulation in the digital age.