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The widespread use of computing and communications technologies has enabled the popularity of social networks oriented to learn. In this work, we study the nature and strength of associations between students using an online social network embedded in a learning management system. With datasets from two offerings of the same course, we mined the sequences of questions and answers posted by the students...
Quality assurance techniques have been developed to supervise the service quality (QoS) agreed between service-based systems (SBSs) consumers and providers. Such QoS is usually included in service level agreements (SLAs) and thus, SLA monitoring platforms have been developed supporting violation detection. However, just a few of them provide explanation of the violations caused by observed QoS at...
Academic Integrity is a fundamental condition for the mission of any university. Ethical problems undermine academic integrity and thus the mission of the university. The College of Engineering at the University of Puerto Rico-Mayagu??ez (UPRM) has developed an ethics across the engineering curriculum program as a space for students and professors to connect engineering and its ethical implications...
This paper presents a novel approach to the problem of discovering and ranking the characteristics of the data sources and query processing sites in a distributed database system. We model the network as a graph with nodes representing data sources and query processing sites, some of which might be replicated.We introduce a heuristic technique inspired in Ant Colony Theory to dynamically discover,assess...
Geocasting is the delivery of messages to all recipients within a specific geospatial region. While good algorithms exist to provide geocasting services, they do not perform well in the presence of large obstacles. We define an obstacle as any region of the network through which a message may not be directly transmitted. Given this definition, we developed a simple mechanism that allows messages to...
If a power factor corrector (PFC) is designed with a fast output-voltage feedback loop, both the steady-state and the dynamic behaviour of this PFC vary in comparison with that obtained when its output-voltage feedback is slow. This is a consequence of the voltage ripple that appears on the control signal, which modifies the converter operation. This voltage ripple is quantified by defining two parameters:...
The expansion of information and communication technology (ICT) infrastructure in the developing world has considerably increased opportunities for people to connect. Today, people can better maintain long-distance relationships as well as be better informed of how their family, close friends, and emotional partners are doing. As a result, many migrants use ICTs to maintain and strengthen ties to...
The envelope tracking technique is used to increment the efficiency of modern radiofrequency transmitters. It is based on supplying the linear radiofrequency power amplifier of the transmitter with a time-varying voltage that tracks the envelope of the information signal being transmitted. These systems require a converter capable of varying its output voltage very fast and a control system able to...
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