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Publications

2016

Software Readability Practices and the Importance of their Teaching

Authors
Sampaio, IB; Barbosa, L;

Publication
2016 7TH INTERNATIONAL CONFERENCE ON INFORMATION AND COMMUNICATION SYSTEMS (ICICS)

Abstract
It is known that code readability has an impact on software quality. This paper introduces a preliminary list of 33 good practices for code readability that could be taught in object oriented programming courses of informatics programs. In this set are included practices with both positive and negative impact, the latter mainly from bad smells. A survey was made with OOP teachers in order to assess the significance of teaching a set of good practices. The results showed that teachers consider it important to teach the defined set. Such result was statistically significant. Still, the same level of significance was not awarded to all practices. Some additional results are presented.

2016

An Adaptive Model Approach for Quantitative Wrist Rigidity Evaluation during Deep Brain Stimulation Surgery

Authors
Assis, S; Costa, P; Rosas, MJ; Vaz, R; Silva Cunha, JPS;

Publication
2016 38TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)

Abstract
Intraoperative evaluation of the efficacy of Deep Brain Stimulation includes evaluation of the effect on rigidity. A subjective semi-quantitative scale is used, dependent on the examiner perception and experience. A system was proposed previously, aiming to tackle this subjectivity, using quantitative data and providing real-time feedback of the computed rigidity reduction, hence supporting the physician decision. This system comprised of a gyroscope-based motion sensor in a textile band, placed in the patients hand, which communicated its measurements to a laptop. The latter computed a signal descriptor from the angular velocity of the hand during wrist flexion in DBS surgery. The first approach relied on using a general rigidity reduction model, regardless of the initial severity of the symptom. Thus, to enhance the performance of the previously presented system, we aimed to develop models for high and low baseline rigidity, according to the examiner assessment before any stimulation. This would allow a more patient-oriented approach. Additionally, usability was improved by having in situ processing in a smartphone, instead of a computer. Such system has shown to be reliable, presenting an accuracy of 82.0% and a mean error of 3.4%. Relatively to previous results, the performance was similar, further supporting the importance of considering the cogwheel rigidity to better infer about the reduction in rigidity. Overall, we present a simple, wearable, mobile system, suitable for intra-operatory conditions during DBS, supporting a physician in decision-making when setting stimulation parameters.

2016

Efficient SQL Adaptive Query Processing in Cloud Databases Systems

Authors
Costa, CM; Maia Leite, CRM; Sousa, AL;

Publication
PROCEEDINGS OF THE 2016 IEEE CONFERENCE ON EVOLVING AND ADAPTIVE INTELLIGENT SYSTEMS (EAIS)

Abstract
Nowadays, many companies have migrated their applications and data to the cloud. Among other benefits of this technology, the ability to answer quickly business requirements has been one of the main motivations. Thereby, in cloud environments, resources should be acquired and released automatically and quickly at runtime. This way, to ensure QoS, the major cloud providers emphasize ensuring of availability, CPU instance and cost measure in their SLAs (Service Level Agreements). However, the QoS performance are not completely handled or inappropriately treated in SLAs. Although from the user's point of view, it is considered one of the main QoS parameters. Therefore, the aim of this work consists in development of a solution to efficient query processing on large databases available in the cloud environments. It integrates adaptive re-optimization at query runtime and their costs are based on the SRT (Service Response Time) QoS performance parameter of SLA. Finally, the solution was evaluated in Amazon EC2 cloud infrastructure and the TPC-DS like benchmark was used for generating a database.

2016

Multi-sensor InSAR deformation monitoring over urban area of Bratislava (Slovakia)

Authors
Bakon, M; Papco, J; Perissin, D; Sousa, JJ; Lazecky, M;

Publication
INTERNATIONAL CONFERENCE ON ENTERPRISE INFORMATION SYSTEMS/INTERNATIONAL CONFERENCE ON PROJECT MANAGEMENT/INTERNATIONAL CONFERENCE ON HEALTH AND SOCIAL CARE INFORMATION SYSTEMS AND TECHNOLOGIES, CENTERIS/PROJMAN / HCIST 2016

Abstract
The integrated use of multiple Synthetic Aperture Radar (SAR) platforms for the deformation monitoring via satellite radar interferometry offers several perspectives for investigation of the behaviour of new and ageing structures, such as buildings and infrastructures, under varying or hazardous environment. Spanning almost 24 years of space-borne radar observations, this study aims to perform classical PSInSAR (Persistent Scatterer Interferometric Synthetic Aperture Radar) analysis incorporating measurements of ERS, Envisat, TerraSAR-X, Sentinel-1A and Radarsat-2 satellites. The results from the processing of different sensing geometries over Bratislava (Slovakia) urban area are presented, focusing on the description of characteristics associated with the specifics of every satellite platform in use. The discussion over technical feasibility of infrastructure monitoring is accompanied by the outline of possible future needs for the utilisation of the wealth source of information provided by the satellite radar imagery. (C) 2016 The Authors. Published by Elsevier B.V.

2016

Perceiving Depth: Optical versus Video See-through

Authors
Medeiros, D; Sousa, M; Mendes, D; Raposo, A; Jorge, J;

Publication
22ND ACM CONFERENCE ON VIRTUAL REALITY SOFTWARE AND TECHNOLOGY (VRST 2016)

Abstract
Head-Mounted Displays (HMDs) and similar 3D visualization devices are becoming ubiquitous. Going a step forward, HMD seethrough systems bring virtual objects to real world settings, allowing augmented reality to be used in complex engineering scenarios. Of these, optical and video see-through systems differ on how the real world is captured by the device. To provide a seamless integration of real and virtual imagery, the absolute depth and size of both virtual and real objects should match appropriately. However, these technologies are still in their early stages, each featuring different strengths and weaknesses which affect the user experience. In this work we compare optical to video see-through systems, focusing on depth perception via exocentric and egocentric methods. Our study pairs Meta Glasses, an off-the-shelf optical see-through, to a modified Oculus Rift setup with attached video-cameras, for video see-through. Results show that, with the current hardware available, the video see-through configuration provides better overall results. These experiments and our results can help interaction designers for both virtual and augmented reality conditions.

2016

Differences between stayers, switchers, and heavy switchers A study in the telecommunications service market

Authors
Moreira, AC; Silva, PM; Moutinho, VF;

Publication
MARKETING INTELLIGENCE & PLANNING

Abstract
Purpose - The purpose of this paper is to identify and compare different groups of customers' perceptions (i.e. stayers, switchers, and heavy switchers) of several loyalty antecedents such as satisfaction, trust, service quality, switching costs, marketing communication, and loyalty itself. Design/methodology/approach - This study was carried out based on data collected through a questionnaire from 353 telecommunication services users in Portugal and using confirmatory factor analysis (CFA) and analysis of variance. Findings - The three types of customers - stayers, switchers, and heavy switchers - clearly differ among themselves. Stayers differ from switchers regarding their communication efforts perceptions, and from heavy switchers in their loyalty, satisfaction, and trust levels. Switchers differ from heavy switchers in their loyalty levels. Research limitations/implications - Future research should examine differences between customers taking into account the impact of their personality, price sensitiveness, and orientation toward the adoption of new technologies. Practical implications - As there are several differences among stayers, switchers, and heavy switchers, companies should not only recognize the heterogeneity of their customer base, but also target their marketing efforts accordingly. Originality/value - This study is one of the few identifying groups of customers perception's toward service providers. It also complements previous research by splitting them intro three different groups and by analyzing their behaviors across a set of previously unexamined marketing variables.

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