Material sound source localization through headphones

[EN] In the present paper a study of sound localization is carried out, considering two different sounds emitted from different hit materials (wood and bongo) as well as a Delta sound. The motivation of this research is to study how humans localize sounds coming from different materials, with the purpose of a future implementation of the acoustic sounds with better localization features in navigation aid systems or training audio-games suited for blind people. Wood and bongo sounds are recorded after hitting two objects made of these materials. Afterwards, they are analysed and processed. On the other hand, the Delta sound (click) is generated by using the Adobe Audition software, considering a frequency of 44.1 kHz. All sounds are analysed and convolved with previously measured non-individual Head-Related Transfer Functions both for an anechoic environment and for an environment with reverberation. The First Choice method is used in this experiment. Subjects are asked to localize the source position of the sound listened through the headphones, by using a graphic user interface. The analyses of the recorded data reveal that no significant differences are obtained either when considering the nature of the sounds (wood, bongo, Delta) or their environmental context (with or without reverberation). The localization accuracies for the anechoic sounds are: wood 90.19%, bongo 92.96% and Delta sound 89.59%, whereas for the sounds with reverberation the results are: wood 90.59%, bongo 92.63% and Delta sound 90.91%. According to these data, we can conclude that even when considering the reverberation effect, the localization accuracy does not sig- nificantly increase. © Pleiades Publishing, Ltd., 2012.This research was supported by Research Center in Graphic Technology from the Universidad Politecnica de Valencia.Dunai, L.; Peris Fajarnes, G.; Lengua, I.; Tortajada Montañana, I. (2012). Material sound source localization through headphones. Acoustical Physics. 58(5):610-617. doi:10.1134/S1063771012050077S610617585D. S. Brungart and W. M. Rabinowitz, J. Acoust. Soc. Am. 106, 1465 (1999).D. S. Brungart, I. Nathaniel, and W. R. Rabinowitz, J. Acoust. Soc. Am. 106, 1956 (1999).H. Bruce and D. Hirsh, J. Acoust. Soc. Am. 31, 486 (1959).D. I. Shore, S. E. Hall, and R. M. Klein, J. Acoust. Soc. Am. 103, 3730 (1998).J. C. Kidd and J. H. Hogloben, J. Acoust. Soc. Am., 116, 1116 (2004).L. Dunai, G. P. Fajarnes, B. D. Garcia, N. O. Araque, and F. B. Simon, Acoust. Phys. 55, 448 (2009).L. Dunai, G. P. Fajarnes, B. D. Garcia, and V. S. Praderas, Acoust. Phys. 56, 348 (2010).M. Gröhn, Proc. Int. Conf. on Auditory Display, Kyoto, 2002.E. S. Malinina and I. G. Andreeva, Acoust. Phys. 56, 576 (2010).E. D. Shabalina, N. V. Shirgina, and A. V. Shanin, Acoust. Phys. 56, 525 (2010).A. Pompey, M. A. Sumbatyan, and N. F. Todorov, Acoust. Phys. 55, 760 (2009).R. L. Klatzky, D. K. Pai, and E. P. Krotkov, Presence: Teleoperators and Virtual Environments 9, 399 (2000).M. Aramaki, M. Besson, R. Kronland-Martinet, and S. Ystad, Proc. 5th Int. Symp. on Comp. Music Model. Retriev. (CMMR 2008), Copenhagen, 2008, pp. 1–8.W. Gaver, PhD Dissertation, Univ. California, San Diego, 1988.N. I. Durlach, A. Rigapolus, X. D. Pang, W. S. Woods, A. Kulkarni, H. S. Colburn, and E. M. Wenzel, Presence: Teleoperators and Virtual Environments 1, 251 (1992).S. A. Gelfand, Essentials of Audiology, 3rd ed. (Thieme Medical Publishers, New York, 2009).J. Jerger, ASHA 4, 139 (1962).H. Mershon, W. L. Ballenger, A. D. Little, P. L. McMurtry, and J. L. Buchanan, Perception 18, 403 (1989).D. O. Kim, A. Moiseff, T. J. Bradley, and J. Gull, Acta Otolaryngologica 128, 328 (2008).P. Zahorik, Proc. Int. Conf. on Auditory Display, Kyoto, 2002

A Hybrid Real-Time Vision-Based Person Detection Method

[EN] In this paper, we introduce a hybrid real-time method for vision-based pedestrian detection made up by the sequential combination of two basic methods applied in a coarse to fine fashion. The proposed method aims to achieve an improved balance between detection accuracy and computational load by taking advantage of the strengths of these basic techniques. Haar-like features combined with Boosting techniques, which have been demonstrated to provide rapid but not accurate enough results in human detection, are used in the first stage to provide a preliminary candidate selection in the scene. Then, feature extraction and classification methods, which present high accuracy rates at expenses of a higher computational cost, are applied over boosting candidates providing the final prediction. Experimental results show that the proposed method performs effectively and efficiently, which supports its suitability for real applications.This work is supported by CASBLIP project 6-th FP\cite{RefCASBLIP}. The authors acknowledge the support of the Technological Institute of Optics, Colour and Imaging of Valencia - AIDO. Dr. Samuel Morillas acknowledges the support of Generalitat Valenciana under grant GVPRE/2008/257 and Universitat Politècnica de València under grant Primeros Proyetos de Investigación 13202. }Oliver Moll, J.; Albiol Colomer, A.; Morillas, S.; Peris Fajarnes, G. (2011). A Hybrid Real-Time Vision-Based Person Detection Method. Waves. 86-95. http://hdl.handle.net/10251/57676S869

Virtual Sound Localization by Blind People

[EN] The paper demonstrates that blind people localize sounds more accurately than sighted people by using monaural and/or binaural cues. In the experiment, blind people participated in two tests; the first one took place in the laboratory and the second one in the real environment under different noise conditions. A simple click sound was employed and processed with non-individual head related transfer functions. The sounds were delivered by a system with a maximum azimuth of 32◦ to the left side and 32◦ to the right side of the participant s head at a distance ranging from 0.3 m up to 5 m. The present paper describes the experimental methods and results of virtual sound localization by blind people through the use of a simple electronic travel aid based on an infrared laser pulse and the time of flight distance measurement principle. The lack of vision is often compensated by other perceptual abilities, such as the tactile or hearing ability. The results show that blind people easily perceive and localize binaural sounds and assimilate them with sounds from the environment.Dunai Dunai, L.; Lengua Lengua, I.; Peris Fajarnes, G.; Brusola Simón, F. (2015). Virtual Sound Localization by Blind People. Archives of Acoustics. 40(4):561-567. doi:10.1515/aoa-2015-0055S56156740

Minimizing Shadow Area in Mountain Roads for Improving the Sustainability of Infrastructures

[EN] The lack of sunlight on mountain roads in the wintertime leads to an increase in accidents. In this paper, a methodology is presented for the use of sunny and shady areas to be included as a parameter in road design. The inclusion of this parameter allows for the design of an iterative method for the projected infrastructures. The parameterization of the road layout facilitates the possibility of applying an iterative process of modifying the geometric elements that constitute it, examining different layout alternatives until a layout is achieved in which the surface area in the shady area is minimized, increasing the road safety and minimizing environmental impact. The methodology has been defined, generating and analyzing the results of the solar lighting study using a file in IFC format capable of integrating with the rest of the design elements (platform, signaling, structures, etc.) and thus obtaining a BIM format which allows the model to be viewed in three dimensions and moves towards 4D and 5D. The model used for the study was a high mountain road located in the province of Teruel (Spain). It is a road section characterized by successive curves in which several traffic accidents have occurred due to running off the road, partly because of the presence of ice on the platform.Aranda Domingo, JÁ.; Moncho-Santonja, M.; Gil Sauri, MA.; Peris Fajarnes, G. (2021). Minimizing Shadow Area in Mountain Roads for Improving the Sustainability of Infrastructures. Sustainability. 13(10):1-16. https://doi.org/10.3390/su13105392S116131

Localización de sonidos en entorno abierto por personas ciegas

[EN] The paper describes the results of virtual sound localization via an object detector in laboratory setting and open environment with blind people. In the tests have been involved two groups of ten blind people. Participants were aged between 25 and 60. The obstacle detection device reproduced 64 sounds at an azimuth of 64° for a distance of between 0.5 m to 5m in a horizontal plane to the level of the eyes. Virtual sounds were reproduced through headphones. For the experiment we used a recorded sound which varies between ¿110dB and ¿23dB with frequency between 86Hz to 18.604Hz. The sound was reproduced 44.1kH frequency and 32 bits, and a duration of 0.04641s. The results show that blind people are able to locate objects by virtually simulated sounds and detect them with high accuracy.[ES] El artículo describe los resultados obtenidos en la localización de sonidos virtuales mediante un dispositivo detector de objetos en entorno de laboratorio y en entorno abierto con personas invidentes. En las pruebas han participado dos grupos de diez personas invidentes. Los participantes tenían edades comprendidas entre 25 y 60 años. El dispositivo detector de obstáculos reproducía 64 sonidos en un azimut de 64º para una distancia de entre 0,5m hasta 5m en un plano horizontal al nivel de los ojos. Los sonidos virtuales se reproducían mediante auriculares. Para el experimento se ha utilizado un sonido grabado que varía entre ¿110dB y ¿23dB con frecuencia entre 86Hz hasta 18.604Hz. El sonido se reprodujo a una frecuencia de 44.1kH y 32 bits, y con una duración de 0.04641s. Los resultados nos muestran que las personas invidentes son capaces de localizar objetos mediante sonidos simulados virtualmente y detectarlos con gran precisión.Lengua, I.; Dunai, L.; Peris Fajarnes, G.; Brusola Simón, F. (2013). Localización de sonidos en entorno abierto por personas ciegas. Revista de Acústica. 43.66:25-29. http://hdl.handle.net/10251/109824S252943.6

Design of a lower-limb exoskeleton

[EN] In recent years, many mechanisms have been developed to help people with reduced mobility, especially for people who have injuries that do not allow the mobility of the lower body of the human body. In the present work, the properties and mechanical movements of a human being, angles of movement, extension and flexion of the hip, knee, etc. are described. A device has also been designed, using aluminum elements to give lightness and robustness to the exoskeleton. At the same time, an external casing made of PLA plastic has been developed, with all of which it has been tried to make a light exoskeleton with a low volume, with the aim that be of daily use for people with mobility problems. Five young students tested the exoskeleton in laboratory conditions. Different parameters have been evaluated as design, range of movement and the functionality. A series of characteristics has been defined such as the design improvement, functionality and navigation, the operating time, speed and data reading with myoelectric sensors after trials[ES] ayuda a las personas con movilidad reducida, especialmente para personas con lesiones que impiden la movilidad de la parte inferior de su cuerpo. En el presente trabajo se revisan inicialmente los fundamentos de los movimientos mecánicos básicos de un ser humano, profundizando en aspectos tales como ángulos de movimiento, extensión y flexión de la cadera, rodilla, etc. Posteriormente, se diseña un exoesqueleto para uso diario por parte de personas con reducida movilidad. Éste está basado en motores de corriente continua (DC), tecnología arduino y en una aplicación móvil para Android. Se utilizan elementos de aluminio para dotar de ligereza y robustez al exoesqueleto y, al mismo tiempo, se elabora una carcasa externa de plástico PLA, con el fin de proveerlo de ligereza, reducido volumen y flexibilidad. El exoesqueleto ha sido ensayado en el laboratorio en cinco individuos. Se han evaluado distintos parámetros como diseño, rango de movimiento y funcionalidad. En base a los resultados obtenidos, se han definido una serie de características a mejorar en el diseño, tales como funcionalidad de navegación, tiempo de funcionamiento, velocidad y lectura de datos mediante sensores mioelectricos.Dunai, L.; Lengua, I.; Peris Fajarnes, G.; Defez Garcia, B. (2019). Diseño de un exoesqueleto de extremidades inferiores. DYNA Ingeniería e Industria. 94(3):297-303. https://doi.org/10.6036/9010S29730394

Health care in rural areas: proposal of a new telemedicine program assisted from the reference health centers, for a sustainable digitization and its contribution to the carbon footprint reduction

[EN] Introduction This paper studies and quantifies the environmental benefits of implementing a new telemedicine service for users of the public health system in a rural area of Alicante (Spain). The proposed telemedicine service is based on carrying out 20% of the follow-on consultations with a specialist virtually from the Reference Health Centres with the support of qualified staff. This way of providing medical care remotely will be a good transition to fully online medical services, especially for the elderly. The proposed model avoids the displacement of users to the Alcoy Hospital, reducing the distances to be travelled, which will be directly reflected in a reduction of the emission of pollutants (carbon footprint) generated by patients' vehicles. Methods Data from the Alcoy Health Department were used for 2019, the last year of normal activity of the health centres before Covid-19. Using data from the Department's health management report and the emission factors of the vehicles, we calculated the distances, hours, litres of fuel saved, as well as the tonnes of CO2 equivalent, CO2, CH4 and N2O. Results With the implementation of this type of telemedicine, journeys would be avoided, saving 447,279 km, 7,580 h and 38,019 L of fuel. The emission into the atmosphere of 79.26 metric tons of CO2, 74.5 kg of CH4 and 487.28 kg of N2O per year would be avoided. Conclusions The implementation of this telemedicine service contributes to a high degree to: (a) increasing the environmental sustainability of the rural health sector thanks to the reduction of traffic emissions (saving 9% of pollutants compared to the current system), (b) decongesting the health system by reducing face-to-face visits to specialists, (c) increasing the quality of life of patients by avoiding road travel (d) promoting the digitalisation of the rural population.Silvia Aparisi-Navarro was supported by Universitat Politecnica de Valencia [PAID-01-2020]. Maria Moncho-Santonja was supported by Conselleria d'Educacio, Investigacio, Cultura i Esport [ACIF-20].Moncho-Santonja, M.; Aparisi-Navarro, S.; Defez Garcia, B.; Davol, A.; Peris Fajarnes, G. (2022). Health care in rural areas: proposal of a new telemedicine program assisted from the reference health centers, for a sustainable digitization and its contribution to the carbon footprint reduction. Heliyon. 8(7):1-6. https://doi.org/10.1016/j.heliyon.2022.e09812168

Strip-pair comparison method for building threshold color-difference model: theoretical model validation

[EN] This paper presents a method for developing color-difference models near a threshold, based on the serial exploration method described by Torgerson [Theory and Methods of Scaling; Wiley & Sons (1958); Chap. 7], involving the construction of color-control strips of patches arranged in arrays of 2 x n, where n is the number of pairs in the strip. The patches in the lower row should be calorimetrically identical, while the color of the patches in the upper row should vary progressively in constant steps of CIELAB color difference along selected color space vector directions. Prospective observers are instructed to indicate the patch pair number for which they begin to perceive a slight color difference between corresponding patches. The frequency data obtained from the observers was used to build a threshold color-difference model. The intention was to validate the method with theoretical data to determine the effect of the precision with which the strips are constructed, on the accuracy of the estimated parameters. Theoretical frequency data was generated using the CIE94 color difference formula, whose associated color discrimination ellipsoid parameters are very easy to determine, associated with a hypothetical logistic psychometric curve for different color centers. The proposed method allows to determine color discrimination parameters with a precision nearby 4% and an accuracy of 3% with respect to the simulated theoretical parameters, for color samples generated with a standard deviation of Delta E*(ab)=0.2 of the superimposed error around the ideal color difference of pairs of patches.Brusola Simón, F.; Tortajada Montañana, I.; Lengua, I.; Jorda-Albiñana, B.; Peris Fajarnes, G. (2020). Strip-pair comparison method for building threshold color-difference model: theoretical model validation. Optics Express. 28(14):21336-21347. https://doi.org/10.1364/OE.395256S2133621347281

Navigation device for blind people based on Time-of-Flight technology

[EN] The paper presents a new navigation and object detector device for blind people based on Time-of-Flight technology and acoustic sounds. The device has been developed as a complementary device for blind people. Its main objective is to detect and localize the obstacles from the environment and inform to the user about their presence through acoustic sounds, both in distance and in azimuth. The device working area is from 0,5m up to 5m in distance and between 30º left and 30º right of the human head, with a precision of 0,9º. The device architecture is based on glasses which contain a 3D-CMOS sensor, an FPGA with the whole electronics and software. After a short experimental period it was possible to demonstrate the importance of the development of such device for the blind community. Due to the acoustic device, blind users were able to detect obstacles from the environment, localize and avoid them.[ES] El artículo presenta un nuevo dispositivo de navegación y detección de obstáculos para las personas ciegas, basado en la tecnología Time-of-Flight y en sonidos acústicos. El dispositivo se ha desarrollado como un dispositivo de ayuda, complementario al bastón, para las personas invidentes. Su objetivo primordial es detectar los obstáculos e informar al usuario mediante sonidos acústicos de la locación de los mismos, tanto en distancia como en dirección. El dispositivo tiene un rango de trabajo entre los 0.5 m y 5 m en distancia y entre 30º izquierda y 30º derecha en azimut, con una precisión de 0,9º. El dispositivo informa a los usuarios mediante auriculares estéreo, de la presencia de los obstáculos situados en su camino. Está compuesto por un sistema de sensores 3D-CMOS montado en un par de gafas de sol, un FPGA que se encarga de procesar la información recibida por los sensores y transformarla en sonidos acústicos, y un par de auriculares estéreo. Las pruebas experimentales llevadas a cabo demuestran el potencial que puede tener para las personas invidentes. Se prueba que con la ayuda del dispositivo acústico los usuarios se sienten más seguros a la hora de transitar por las calles, debido a que tienen una amplia información sobre el entorno que los rodea, más allá de la obtenida con el bastón.El trabajo ha sido apoyado por el proyecto Nº 2062 del programa PAID-06-11 de la Universitat Politècnica de València.Lengua, I.; Dunai, L.; Peris Fajarnes, G.; Defez Garcia, B. (2013). Dispositivo de navegación para personas invidentes basado en la tecnología Time of Flight. DYNA. 80(179):33-41. http://hdl.handle.net/10251/70683S33418017

Hough Transform Sensitivity Factor Calculation Model Applied to the Analysis of Acne Vulgaris Skin Lesions

[EN] The number of infectious spots or pathological structures recorded on dermatological images is a tool to aid in the diagnosis and monitoring of disease progression. Dermatological images for the detection and monitoring of the evolution of acne infections are evaluated globally, comparing whether the increase or decrease in infectious lesions appearing on an image is significant. This evaluation method is only indicative since its accuracy is low. The accuracy problem could be improved by an exact count of the number of structures and spots appearing on the image. The mathematical function circular Hough transform (CHT) function implemented in MATLAB is here applied to develop a procedure for counting these structures. CHT has been used in the recognition of benign and distorted red blood cells, in the detection of pellet sizes in industrial processes and in the automated detection and morphological characterization of breast tumor masses from infrared images, as well as for the detection of brain aneurysms and use in magnetic resonance imaging. The sensitivity factor is one of the many parameters required to feed the CHT algorithm. Its choice is unclear as there is no proper methodology to select an optimum value suitable for each image. In this work, a procedure for determining the optimal value of the sensitivity factor is proposed The approach is validated by comparison with the results of the manual counting of the points (ground truth).This work was supported for publication by the Conselleria de Innovación, Universidades, Ciencia y Sociedad Digital of the Generalitat Valenciana. All this work has been done in the CITG (Research Centre in Graphic Technologies) at the Universitat Politècnica de València.Moncho-Santonja, M.; Micó-Vicent, B.; Defez Garcia, B.; Jordán-Núñez, J.; Peris Fajarnes, G. (2022). Hough Transform Sensitivity Factor Calculation Model Applied to the Analysis of Acne Vulgaris Skin Lesions. Applied Sciences. 12(3):1-12. https://doi.org/10.3390/app12031691S11212