Cayetano Guerra Artal

Universidad de Las Palmas de Gran Canaria | ULPGC · Department of Computer Sciences and Systems

In task-oriented dialogue systems, the ability for users to effortlessly communicate with machines and computers through natural language stands as a critical advancement. Central to these systems is the dialogue manager, a pivotal component tasked with navigating the conversation to effectively meet user goals by selecting the most appropriate res...

The use of Transformer based architectures has been extended in recent years, reaching the level of State of the Art (SOTA) in numerous tasks in the field of Natural Language Processing (NLP). However, despite the advantages of this architecture, it has some negative factors, such as the high number of parameters it uses. That is why the use of thi...

The learning effectiveness of video lectures has been extensively studied by the scientific community, but research on their cost-effectiveness and sustainable production is still very scarce. To shed light on these aspects, this study has measured the useful life span and cost-effectiveness of a large catalog of video lectures produced for undergr...

Monolithic neural networks and end-to-end training have become the dominating trend in the field of deep learning, but the steady increase in complexity and training costs has raised concerns about the effectiveness and efficiency of this approach. We propose modular training as an alternative strategy for building modular neural networks by compos...

Training a Neural Network (NN) with lots of parameters or intricate architectures creates undesired phenomena that complicate the optimization process. To address this issue we propose a first modular approach to NN design, wherein the NN is decomposed into a control module and several functional modules, implementing primitive operations. We illus...

Purpose: This paper offers an account of the current usage of communication styles and features in MOOC instructional videos. The aim of the study is to provide a better understanding of instructional video patterns and typologies and to find associations between video style usage and course attributes such as the MOOC platform and course subjects....

The use of instructional videos to support the teaching-learning process in higher education has been increasing in recent years. Videos and all other kinds of audiovisual objects are being published on online learning platforms and MOOCs. In this context, a noticeable concern is how to produce quality material that maximizes its learning effective...

Nowadays, it is not possible to think about teaching and learning processes without the use of some kind of digital technology. Computers, digital networks, software applications, multimedia objects and learning management systems conform a new technological environment that has to be understood by the community of teachers, students and education...

"Prometeo" is an innovative online platform at the Universidad de Las Palmas de Gran Canaria (ULPGC, Spain) that combines multimedia content with digital mediated learning. A team of computer specialists has worked on the audiovisual production, programming systems and graphic design in order to help teachers create multimedia material for their st...

Currently, there are a lot of educational materials like texts, presentations, graphics, audios and videos that teachers can produce by themselves. Probably, video production is the most complicated kind because it involves more technical knowledge. "Picasst" is an innovative web-based software tool that facilitates both the creation of audio-visua...

To develop and assess the technical validity of new computer-aided diagnostic software (CAD) for automated analyses of optical coherence tomography (OCT) images for the purpose of screening for neovascular age-related macular degeneration. Artificial visual techniques were used to develop the CAD in two steps: normalisation and feature vector extra...

In this paper, we present the modelling of a real-time tracking system on a Multi-Processor System on Chip (MPSoC). Our final goal is to build a more complex computer vision system (CVS) by integrating several applications in a modular way, which performs different kind of data processing issues but sharing a common platform, and this way, a soluti...

In this paper, we present the strategy for evaluating the performance of a variety of configurations of an architecture template for a computer vision system (CVS). For this study a generic model of an architecture is used to address the modular design of the CVS. This modular nature approach could be used to build a more complex system by integrat...

In the same manner that e-learning applications are becoming increas-ingly important at the university, there are still some critical questions that should be solved with the objective of making use of the potential offered by current Web Tech-nologies. The creation of contents that are able of capturing the attention of interest of the students an...

The advance of Internet towards Web 2.0 conveys the potential it has in a wide range of scopes. The ongoing progress of the Web technology and its availability in teaching and learning, as well as a students' profile increasingly more used to managing an important amount of digital information, offers lecturers the opportunity and challenge of putt...

This paper describes a face detection system which goes beyond traditional face detection approaches normally designed for still images. The system described in this paper has been designed taking into account the temporal coherence contained in a video stream in order to build a robust detector. Multiple and real-time detection is achieved by mean...

This work presents a comparison among different focus measures used in the literature for autofocusing in a non previously explored application of face detection. This application has different characteristics to those where traditionally autofocus methods have been applied like microscopy or depth from focus. The aim of the work is to find if the...

This paper presents a system for hand posture recognition that works with colour video streams under varying light conditions for human-machine interaction in vision-based interface tasks. No initialization of the system is required and no user dependence is involved. With this aim, we first model on-line each user’s skin colour from the skin cue i...

RESUMEN Este trabajo presenta un simulador de vuelo que permite una experiencia de vuelo virtual en tiempo real sobre la isla de "El Hierro" (Islas Canarias). Características como precisión y gradualidad en el movimiento son determinantes en el simulador de vuelo. Se describen las tareas de desarrollo y los resultados que demuestran las etapas del...

The main goal of this project1 has been the development of an application that allows flying virtually over El Hierro Island (Canary Islands), showing the building structures of a hydroelectric power station that is in construction. Input data consisted of: • Aerial photos at 1:5.000 scale of the island surface (1 m2 each pixel). • Height map of th...

Tracking is a basic process for security and surveillance problems that need to follow an object of interest during a certain period of time. Visual tracking algorithms based on pattern matching techniques constitute the basis of many, and the most used, current tracking systems (Brown, 1992). However, the main drawback of template matching consist...

Many methods have been developed to calibrate cameras, but very few works have been done to compare such methods or to provide the user with hints on the suitability of certain algorithms under particular circum-stances. This work presents a comparative analysis of eight methods of calibration for cameras using a pattern as reference. This paper co...

This document presents an operating version of CoolBOT, a component oriented software framework for programming robotic systems, that was already presented in WAF'2002 [3] when it was at the beginning of its development. CoolBOT has been designed having in mind the idea of programming by integrating software components, in order to reduce the devel...

An emergent field of robotics, which we may call social robotics, aims at building robots that have abilities to interact with people. These robots have expressive power (i.e. they have an expressive face, voice, etc.) as well as abilities to locate, pay attention to, and address people. For this class of robots, the dominant design approach has be...

Visual tracking based on pattern matching is a very used computer vision technique in a wide range of applications [3]. Updating the template of reference is a crucial aspect for a correct working of this kind of algorithms. This work proposes a new approach to the updating problem in order to achieve a better performance and robustness of tracking...

The development and maintenance of software for robotic systems is a hard task due to the complexity inherent in these systems. Besides, the resulting applications have to deal with limited resources and variable execution conditions that must be considered in order to keep an acceptable system performance. To address both problems we have integrat...

This paper describes a face detection system which goes beyond traditional approaches normally designed for still images. First the video stream context is considered to apply the detector, and therefore, the resulting system is designed taking into consideration a main feature available in a video stream, i.e. temporal coherence. The resulting sys...

In this work an approach to an adaptive vision system is presented. It is based on a homeostatic approach where the system state is represented as a set of artificial hormones which are affected by the environmental changes. To compensate these changes, the vision system is endowed with drives which are in charge of modifying the system parameters...

Visual tracking based on pattern matching is a very used computer vision technique in a wide range of applications [4]. Updating the template of reference is a crucial aspect for a correct working of this kind of algorithms. This paper proposes a new approach to the updating problem in order to achieve a better performance and robustness of trackin...

Reliable and real-time face detection is a basic ability for any Vision Based Interface. This paper combines and exploits the benefits of two different face detectors specialized each one in a specific context. The resulting system improves their respective individual performances by means of their cooperation, the integration of temporal coherence...

Reliable and real-time face detection is a basic ability for any Vision Based Interface. This paper combines and exploits the bene¯ts of two di®erent face detectors specialized each one in a speci¯c context. The resulting system improves their respective individual performances by means of their cooperation, the integration of temporal coherence, p...

The physical appearance and behavior of a robot is an important asset in terms of Human-Computer Interaction. Multimodality is also fundamental, as we humans usually expect to interact in a natural way with voice, gestures, etc. People approach complex interaction devices with stances similar to those used in their interaction with other people. In...

In this paper we will present Eldi, a mobile robot that has been in operation at the Elder Museum of Science and Technology at Las Palmas de Gran Canaria since December 1999. This is an ongoing project that was organized in three different stages of which only the first one has been accomplished. The initial phase, termed “The Player”, the second s...

In this paper we will present Eldi, a mobile robot that has been in daily operation at the Elder Museum of Science and Technology at Las Palmas de Gran Canaria since December 1999. The system that controls Eldi and the rest of the installation has been conceived as a set of agents that interact by means of discrete events. This is an ongoing projec...

In this paper we will present Eldi, a mobile robot that has been in daily operation at the Elder Museum of Science and Technology at Las Palmas de Gran Canaria since December 1999. This is an ongoing project that was organized in three different stages, describing here the one that has been accomplished. The initial phase, termed "The Player", the...

In this paper, a basic conceptual architecture aimed at the design of Computer Vision System is qualitatively described. The proposed architecture addresses the design of vision systems in a modular fashion using modules with three distinct units or components: a processing network or diagnostics unit, a control unit and a communications unit. The...

This paper describes an Active Vision System whose design assumes a distinction between fast or reactive and slow or background processes. Fast processes need to operate in cycles with critical timeouts that may affect system stability. While slow processes, though necessary, do not compromise system stability if its execution is delayed. Based on...

This paper describes a face detection system conceived to process video streams in real-time. Cue combination allows the system to tackle the temporal restrictions achieving a notable detection rate. The system developed is able to detect simultaneously at different resolutions multiple individuals building a feature based model for each detected f...

In this paper, the introduction of a homeostatic regulation mechanism in a vision system is proposed. This homeostatic mechanism takes charge of controlling the luminance, white balance, contrast and size of the object of interest in the image, using naive methods except for the contrast, for which we have implemented a method that avoids the hill...

This document presents an operating version of CoolBOT, a component oriented software frame- work for programming robotic systems, that was al- ready presented in WAF'2002 (3) when it was at the beginning of its development. CoolBOT has been designed having in mind the idea of programming by integrating software components, in order to re- duce the...