Use of Mel Frequency Cepstral Coefficients for Automatic Pathology Detection on Sustained Vowel Phonations: Mathematical and Statistical Justification

This paper presents a justification for the use of MFCC parameters in automatic pathology detection on speech. While such an application has produced good results up to now, only partial explanations to this good performance had been given before. The herein exposed explanation consists of an interpretation of the mathematical transformations involved in MFCC calculation and a statistical analysis that confirms the conclusions drawn from the theoretical reasoning

Use of Cepstrum-based parameters for automatic pathology detection on speech. Analysis of performance and theoretical justification

The majority of speech signal analysis procedures for automatic pathology detection mostly rely on parameters extracted from time-domain processing. Moreover, calculation of these parameters often requires prior pitch period estimation; therefore, their validity heavily depends on the robustness of pitch detection. Within this paper, an alternative approach based on cepstral-domain processing is presented which has the advantage of not requiring pitch estimation, thus providing a gain in both simplicity and robustness. While the proposed scheme is similar to solutions based on Mel-frequency cepstral parameters, already present in literature, it has an easier physical interpretation while achieving similar performance standards

Detección del espacio glotal en imágenes laríngeas mediante transformada Watershed y Merging JND

El presente artículo describe un nuevo método para la detección del espacio glotal en imágenes laríngeas obtenidas de vídeos de alta o baja velocidad. El proceso de detección basa su eficacia en la combinación de varias técnicas de gran relevancia en el campo del tratamiento digital de imágenes. Una de estas técnicas es la transformada Watershed que junto con varios tipos de Merging y un proceso final de predicción lineal, hacen posible la detección automática en un 99% de las imágenes analizadas. La potencia del método se ve incrementada por la ausencia de cualquier tipo de inicialización y por no necesitar condiciones estrictas sobre las características de las imágenes a procesar. Evidentemente es importante que el algoritmo integre información a priori del espacio glotal, pero este conocimiento es bastante relajado comparado con las condiciones impuestas por otros trabajos que también intentan la segmentación

Screening voice disorders with the glottal to noise excitation ratio

This work evaluates the capabilities of the Glottal to Noise Excitation Ratio for the screening of voice disorders. A lot of effort has been made using this parameter to evaluate voice quality, but there do not exist studies that evaluate the discrimination capabilities of this acoustic parameter to classify between normal and pathological voices. A set of 226 speakers (53 normal and 173 pathological) taken from a voice disorders database were used to evaluate the usefulness of this parameter for discriminating normal and pathological voices. In order to evaluate this parameter, the effect of the bandwidth of the Hilbert envelopes and the frequency shift have been analyzed, concluding that a good discrimination is obtained with a bandwidth of 1000 Hz and a frequency shift of 300 Hz. The results confirm that the Glottal to Noise Excitation Ratio provides reliable measurements in terms of discrimination among normal and pathological voices, comparable to other classical long-term noise measurements found in the literature, such as Normalized Noise Energy or Harmonics to Noise Ratio, so this parameter is a good candidate to be used for screening purposes

An error based mathematical module to enhance learning in signals and systems

During the last years, the lecturers at the Circuits and Systems Engineering Department at the E.U.I.T. de Telecomunicación at the Universidad Politécnica de Madrid are observing more and more serious mathematical errors in the different exams and exercises taken by the students. Although some of these mistakes can be considered unacceptable in engineering disciplines, it is possible for a student to pass the final exam regardless of these mistakes. In this scenario, and aware that results were getting worse and worse year after year, it was considered convenient, and almost indispensable, to develop math exercises that students must practice if they want to progress following a continuous and formative assessment method along their engineering studies. The first part of this work is to analyze basic mathematical errors in final exam exercises of the course “Signals and Systems”. We present and illustrate the most relevant errors detected during the last two years final exams of that course. The information obtained permits us to identify the main lacks, difficulties and defaults of the students. The second part of this work is to develop a training module in order to the students can practice as many times as they want with simple exercises dealing with the topics where frequent errors are detected. After practicing they must pass an initial test to make sure that students have acquired the adequate basic mathematical background and skills to progress successfully in the mentioned course. The questions and exercises have been written using different formats, most of them to be compatible with Moodle platform requirements

Preprocesado Avanzado de Imágenes Laríngeas para Mejorar la Segmentación del Área Glotal

El presente trabajo describe un método avanzado de preprocesado de imagen para mejorar la detección automática del espacio glotal en imagines laríngeas. El sistema puede aplicarse a imágenes obtenidas a partir de exploraciones de alta velocidad o a partir de exploraciones estroboscópicas (baja velocidad), aunque es en estas últimas donde se observan las mayores ventajas, al tratarse de grabaciones de inferior calidad. Con esta nueva técnica de preprocesado se logran resolver ciertos fallos de segmentación producidos por un sistema previo basado en transformada “Watershed” y “Merging”. En resumen, se consiguen arreglar o mejorar el 38% de los errores de delineado de la glotis que aparecían en 29 imágenes de un total de 111 segmentadas

Learning English is fun! Increasing motivation through video games

In this paper we present a study made with 16 university students with different levels of proficiency in English, who were divided into two groups: those with a basic level (B1 or lower) and those who had an advanced one (B2 or higher). These two groups had the opportunity to get to know and interact with a serious game developed in the ?Universidad Politécnica de Madrid? with the aim of helping in the teaching-learning process of English as a foreign language. Before and after the interaction, all students were interviewed on various aspects related to the English learning process. Although the results show some differences in the two groups, they mainly agree in that the use of the video game greatly increases their motivation to learn English, even though they also consider that they would be able to reach the same English level studying in a more traditional way. In addition, when the students were straightly asked about the usefulness of the video game to learn English, their answers in a graded scale of agreement, ranging from 1 to 5, had an average value of 3.76

Cheating and learning through web based tests

The use of web-based tests delivered through learning management systems has grown at university level in the last years. One of their key advantages is the possibility of creating tests with some degree of randomness that are automatically assessed in real time. Although the access to the learning management system resources is controlled for each student by means of personal username and password, the cheating among students when doing the tests cannot be avoided. However, if the students finally learn, in spite of cheating, the process could still be considered to be successful. In this work, the date, the required time to solve the test and the grades of quizzes undertaken by students through a web based learning management system are analyzed and they are compared to the grades obtained by the same students in a written test solved in an examination classroom under the supervision of the teacher. The course in which this study has been developed (Signals and Systems for Electrical and Electronics Engineering undergraduate students) is organized in 5 subjects and the students make a quiz on the web for each subject. At the end of the course the students make a final written exam that includes a true/false test. Around 50 questions for each subject of the course have been created. The questions are organized in 5 to 8 categories for each subject. The learning management system generates quizzes by arbitrarily selecting 1 or 2 items from the 5 to 8 categories in a given subject to complete a 10-item quiz. Due to the reduced number of items for each category and the large number of students that attend the course, several questions are repeated in quizzes generated for different students. The authors have noticed that some students work in groups to solve the quizzes. Some of them answer all the questions in a quiz in few minutes (less than 20 % of the time used by the most of their mates) and obtain high scores. When the scores of the same students in the final exam are analyzed, it is found that they also obtain good results. Then, it could be concluded that although they have found a way of cheating to solve the web quizzes, this is still pedagogically valid because they have learnt about the subject (they also obtain good results in the written test)

MedivozCaptura. Una aplicación en red segura de ayuda al profesional de ORL

MedivozCaptura es una herramienta informática desarrollada para asistir al análisis y detección de patologías vocales. Se basa en el almacenamiento en una base de datos relacional de señales de voz, electroglotogramas (EGG) y vídeoendoscopias, además de otros datos sobre los pacientes que los especialistas puedan considerar relevantes. El presente documento describe el funcionamiento de la aplicación de forma distribuida en red, con la base de datos centralizada, así como la problemática de seguridad y rendimiento que supone la distribución a través de la red o Internet y cómo se solventa en MedivozCaptur

Development of a puncture electronic device for electrical conductivity measurements throughout meat salting

Conductivity measurements of food systems are of high interest because they are related with food characteristics such as free water and salt content. Nevertheless, as far as now no devices have been developed for punctual conductivity measurements inside solid foods. The aim of this work was to develop a conductimeter which allows obtaining punctual measurements in different locations of solid foods. The sensor consists of a coaxial needle while an electrical sign controlled by microcontroller is applied. The preliminary results indicate that the obtained response is proportional to the conductivity and the salt content in the zone of measurement of the food, being possible its use for salted food analysis and control