A game-based approach to the teaching of object-oriented programming languages

Students often have difficulties when trying to understand the concepts of object-oriented programming (OOP). This paper presents a contribution to the teaching of OOP languages through a game-oriented approach based on the interaction with tangible user interfaces (TUIs). The use of a specific type of commercial distributed TUI (Sifteo cubes), in which several small physical devices have sensing, wireless communication and user-directed output capabilities, is applied to the teaching of the C# programming language, since the operation of these devices can be controlled by user programs written in C#. For our experiment, we selected a sample of students with a sufficient knowledge about procedural programming, which was divided into two groups: The first one had a standard introductory C# course, whereas the second one had an experimental C# course that included, in addition to the contents of the previous one, two demonstration programs that illustrated some OOP basic concepts using the TUI features. Finally, both groups completed two tests: a multiple-choice exam for evaluating the acquisition of basic OOP concepts and a C# programming exercise. The analysis of the results from the tests indicates that the group of students that attended the course including the TUI demos showed a higher interest level (i.e. they felt more motivated) during the course exposition than the one that attended the standard introductory C# course. Furthermore, the students from the experimental group achieved an overall better mark. Therefore, we can conclude that the technological contribution of Sifteo cubes – used as a distributed TUI by which OOP basic concepts are represented in a tangible and a visible way – to the teaching of the C# language has a positive influence on the learning of this language and such basic concepts

Influence of Input/output Operations on Processor Performance

Nowadays, computers are frequently equipped with peripherals that transfer great amounts of data between them and the system memory using direct memory access techniques (i.e., digital cameras, high speed networks, . . . ). Those peripherals prevent the processor from accessing system memory for significant periods of time (i.e., while they are communicating with system memory in order to send or receive data blocks). In this paper we study the negative effects that I/O operations from computer peripherals have on processor performance. With the help of a set of routines (SMPL) used to make discrete event simulators, we have developed a configurable software that simulates a computer processor and main memory as well as the I/O scenarios where the periph-erals operate. This software has been used to analyze the performance of four different processors in four I/O scenarios: video capture, video capture and playback, high speed network, and serial transmission

TPU Cloud-Based Generalized U-Net for Eye Fundus Image Segmentation

Medical images from different clinics are acquired with different instruments and settings. To perform segmentation on these images as a cloud-based service we need to train with multiple datasets to increase the segmentation independency from the source. We also require an ef cient and fast segmentation network. In this work these two problems, which are essential for many practical medical imaging applications, are studied. As a segmentation network, U-Net has been selected. U-Net is a class of deep neural networks which have been shown to be effective for medical image segmentation. Many different U-Net implementations have been proposed.With the recent development of tensor processing units (TPU), the execution times of these algorithms can be drastically reduced. This makes them attractive for cloud services. In this paper, we study, using Google's publicly available colab environment, a generalized fully con gurable Keras U-Net implementation which uses Google TPU processors for training and prediction. As our application problem, we use the segmentation of Optic Disc and Cup, which can be applied to glaucoma detection. To obtain networks with a good performance, independently of the image acquisition source, we combine multiple publicly available datasets (RIM-One V3, DRISHTI and DRIONS). As a result of this study, we have developed a set of functions that allow the implementation of generalized U-Nets adapted to TPU execution and are suitable for cloud-based service implementation.Ministerio de Economía y Competitividad TEC2016-77785-

Application of bus emulation techniques to the design of a PCI/MC68000 bridge

Bridges easy the interconnection and communication of devices that operate using different buses. In fact, we can see a computer as a hierarchy of buses to which devices are connected. In this paper we design a PCI/MC68000 bridge in order to improve communications between a Personal Computer and a MC68000 based system. The previous interface between both devices was based on the old 16-bit ISA bus, which represented a bottleneck in their communication. However, the methodology described here is generic and can be applied to the design of PCI bridges to other buses. We finish this work with an analysis of the bridge performance improvement which can also be easily adapted to other situations. As an example our interface is used in an interesting situation, i.e., updating the obsolete control unit of a highly valuable system (an industrial robot)

Radio-frequency heating of the cornea: theoretical model and in vitro experiments

[EN] We present a theoretical model for the study of cornea heating with radio-frequency currents. This technique is used to reshape the cornea to correct refractive disorders. Our numerical model has allowed the study of the temperature distributions in the cornea and to estimate the dimensions of the lesion. The model incorporates a fragment of cornea, aqueous humor, and the active electrode placed on the cornea surface. The finite element method has been used to calculate the temperature distribution in the cornea by solving a coupled electric-thermal problem. We analyzed by means of computer simulations the effect of: a) temperature influence on the tissue electrical conductivity; b) the dispersion of the biological characteristics; c) the anisotropy of the cornea thermal conductivity; d) the presence of the tear film; and e) the insertion depth of the active electrode in the cornea, and the results suggest that these effects have a significant influence on the temperature distributions and thereby on the lesion dimensions. However, the cooling of the aqueous humor in the endothelium or the realistic value of the cornea curvature did not have a significant effect on the temperature distributions. An experimental model based on the lesions created in rabbit eyes has been used in order to compare the theoretical and experimental results. There is a tendency toward the agreement between experimental and theoretical results, although we have observed that the theoretical model overestimates the lesion dimension.Berjano, E.; Saiz Rodríguez, FJ.; Ferrero Corral, JM. (2002). Radio-frequency heating of the cornea: theoretical model and in vitro experiments. IEEE Transactions on Biomedical Engineering. 49(3):196-205. doi:10.1109/10.983453S19620549

Block-Based Development of Mobile Learning Experiences for the Internet of Things

The Internet of Things enables experts of given domains to create smart user experiences for interacting with the environment. However, development of such experiences requires strong programming skills, which are challenging to develop for non-technical users. This paper presents several extensions to the block-based programming language used in App Inventor to make the creation of mobile apps for smart learning experiences less challenging. Such apps are used to process and graphically represent data streams from sensors by applying map-reduce operations. A workshop with students without previous experience with Internet of Things (IoT) and mobile app programming was conducted to evaluate the propositions. As a result, students were able to create small IoT apps that ingest, process and visually represent data in a simpler form as using App Inventor's standard features. Besides, an experimental study was carried out in a mobile app development course with academics of diverse disciplines. Results showed it was faster and easier for novice programmers to develop the proposed app using new stream processing blocks.Spanish National Research Agency (AEI) - ERDF fund

A Dynamic Equilibrium View of Caching Systems

In this paper, we present a simple analytical study of caching systems based on the idea of dynamic equilibrium of cache blocks, assuming the Independent Reference Model (IRM) of references. This method allows us to obtain simple closedform expressions for parameters that are usually excluded from cache studies, such as the mean number of reads or writes per cache block while in the cache. We finally present some simulation results in order to validate the analysis.Ministerio de Educación y Ciencia TIN2006-15617- C03-03Junta de Andalucía P06-TIC-229

Frequency Analysis of a 64x64 Pixel Retinomorphic System with AER Output to Estimate the Limits to Apply onto Specific Mechanical Environment

The rods and cones of a human retina are constantly sensing and transmitting the light in the form of spikes to the cortex of the brain in order to reproduce an image in the brain. Delbruck’s lab has designed and manufactured several generations of spike based image sensors that mimic the human retina. In this paper we present an exhaustive timing analysis of the Address-Event- Representation (AER) output of a 64x64 pixels silicon retinomorphic system. Two different scenarios are presented in order to achieve the maximum frequency of light changes for a pixel sensor and the maximum frequency of requested directions on the output AER. Results obtained are 100 Hz and 1.66 MHz in each case respectively. We have tested the upper spin limit and found it to be approximately 6000rpm (revolutions per minute) and in some cases with high light contrast lost events do not exist.Ministerio de Ciencia e Innovación TEC2009-10639- C04-0

Transfer of innovation - using research tools for engineering education

In this article, the authors show how, in the pursuit of research results, they can obtain excellent tools and data for engineering education. In particular, they describe one example of computer architecture in the Computer Engineering Degree Programme at the University of Cádiz in Spain. This research topic is of particular importance as it influences the execution of a range of the computer’s I/O operations, due to operations of peripherals and information devices, and determines processor performance. The simulator used in research and teaching in several engineering degree programmes at the University of Cádiz is also demonstrated in this article

Ejercicios de fundamentos de informática. Test y ejercicios resueltos

Esta obra pretende ser útil y práctica, no solo para nuestro alumnado, sino para los de otras Universidades, de Enseñanzas Medias e incluso personas que desearan prepararse una oposición en cuyos contenidos se incluyeran temas de Informática Básica. Ejercicios de Fundamentos de Informática se compone de cuatro capítulos, cada uno de los cuales consta de un conjunto de problemas resueltos y una serie de preguntas tipo test. Ejercicios de Fundamentos de Informática no es una obra acabada, sino que está abierta a sugerencias para futuras modificaciones y mejoras. Por ello, desde aquí animamos a los lectores a que nos hagan llegar todas las sugerencias que consideren oportunas, para que entre todos hagamos un libro cada vez más útil y mejor adaptado a nuestras necesidades