Littérature scientifique sur le sujet « Thomson's multitaper »

The Mel Frequency Cepstral Coefficients (MFCCs) are widely used in order to extract essential information from a voice signal and became a popular feature extractor used in audio processing. However, MFCC features are usually calculated from a single window (taper) characterized by large variance. This study shows investigations on reducing variance for the classification of two different voice qualities (normal voice and disordered voice) using multitaper MFCC features. We also compare their performance by newly proposed windowing techniques and conventional single-taper technique. The results demonstrate that adapted weighted Thomson multitaper method could distinguish between normal voice and disordered voice better than the results done by the conventional single-taper (Hamming window) technique and two newly proposed windowing methods. The multitaper MFCC features may be helpful in identifying voices at risk for a real pathology that has to be proven later.

Digital natives’ generation is inseparable from gadgets, less socializing, lack of creativity and being an individualist. The digital native’s generation wants things that are instant and lack respect for the process. The preoccupation of children with gadgets makes children socially alienated or known as anti-social. Preschool play an important role in the development of the digital native’s generation and in the future can help children use gadgets with parents. As it is known, the digital native’s generation is a kindergarten child. This study aims to determine the role of preschools in helping the use of gadgets in the digital native generation. This study used a descriptive quantitative approach with simple random sampling technique was obtained 25 kindergarten principals in Pekanbaru City. Data was collected in the form of a questionnaire via google form. Data analysis uses percentages and is presented in the tabular form. The results of the study indicate that the role of preschools in the use of gadgets in digital native generation children in Pekanbaru City is included in the low category. Only a few preschools have organized parenting education for parents. There are almost no rules governing children's use of gadgets at home, and few preschools educate children on how to use gadgets properly. It is expected for teachers and preschools to add special programs in the curriculum to provide information about positive gadget use and parenting programs that discuss digital native generation and collaborate with parents to establish rules such as frequency, duration and content of children using gadgets. Keywords: Digital Native, Preschool, Gadgets References: Alia, T., & Irwansyah, I. (2018). Pendampingan orang tua pada anak usia dini dalam penggunaan teknologi digital [parent mentoring of young children in the use of digital technology]. Polyglot: Jurnal Ilmiah, 14(1), 65–78. Allen, K. A., Ryan, T., Gray, D. L., McInerney, D. M., & Waters, L. (2014). Social Media Use and Social Connectedness in Adolescents: The Positives and the Potential Pitfalls. The Australian Educational and Developmental Psychologist, 31(1), 18–31. https://doi.org/10.1017/edp.2014.2 Berlin, A., Törnkvist, L., & Barimani, M. (2016). Content and Presentation of Content in Parental Education Groups in Sweden. The Journal of Perinatal Education, 25(2), 87–96. https://doi.org/10.1891/1058-1243.25.2.87 Chapman, G., & Pellicane, A. (2014). Growing up social: Raising relational kids in a screen-driven world. Moody Publishers. Cho, K.-S., & Lee, J.-M. (2017). Influence of Smartphone Addiction Proneness of Young Children on Problematic Behaviors and Emotional Intelligence. Comput. Hum. Behav., 66(C), 303–311. https://doi.org/10.1016/j.chb.2016.09.063 Coie, J. D., & Dodge, K. A. (1988). Multiple sources of data on social behavior and social status in the school: A cross-age comparison. Child Development, 815–829. Crouch, A. (2017). Tech-Wise Family. Everyday Steps for Putting Technology in Its Proper Place. Baker Books. De Lima, L., & Castronuevo, E. (2016). Perception of parents on children’s use of gadgets. The Bedan Journal of Psychology, II, 26–34. Gani, S. A. (2017). Parenting Digital Natives: Cognitive, Emotional, and Social Developmental Challenges. Guralnick, M. J. (1999). Family and child influences on the peer‐related social competence of young children with developmental delays. Mental Retardation and Developmental Disabilities Research Reviews, 5(1), 21–29. Hosokawa, R., & Katsura, T. (2018). Association between mobile technology use and child adjustment in early elementary school age. PloS One, 13(7), e0199959. Jonathan, L. P., & Andrew, L. F. (2016). Depression in children and adolescents. University of Kansas, Clinical Child Psychology Program. Kabali, H. K., Irigoyen, M. M., Nunez-Davis, R., Budacki, J. G., Mohanty, S. H., Leister, K. P., & Bonner, R. L. (2015). Exposure and Use of Mobile Media Devices by Young Children. PEDIATRICS, 136(6), 1044–1050. https://doi.org/10.1542/peds.2015-2151 Kirschner, P. A., & De Bruyckere, P. (2017). The myths of the digital native and the multitasker. Teaching and Teacher Education, 67, 135–142. https://doi.org/10.1016/j.tate.2017.06.001 Kurniawan, A. R., Chan, F., Sargandi, M., Yolanda, S., Karomah, R., Setianingtyas, W., & Irani, S. (2019). Kebijakan Sekolah Dalam Penggunaan Gadget di Sekolah Dasar [School Policy on the Use of Gadgets in Elementary Schools]. Jurnal Tunas Pendidikan, 2(1), 72–81. Martin, D. J. (2001). Constructing Early Childhood Science. Delmar Thomson Learning, Inc,. Morrongiello, B. A., McArthur, B. A., Goodman, S., & Bell, M. M. (2015). Don’t touch the gadget because it’s hot! Mothers’ and children’s behavior in the presence of a contrived hazard at home: Implications for supervising children. Journal of Pediatric Psychology, 40 1, 85–95. Mueller, S., Remaud, H., & Chabin, Y. (2011). How strong and generalisable is the Generation Y effect? A cross‐cultural study for wine. International Journal of Wine Business Research, 23(2), 125–144. https://doi.org/10.1108/17511061111142990 NAEYC. (2012). Technology and interactive media as tools in early childhood programs serving children from birth through age 8. National Institute for Educational Policy Research. (2014). Zenkoku Gakuryoku Gakusyu Jyokyo Cyosa [Japanese]. Nielsen Company. (2009). Television, Internet, and mobile usage in the U.S.: A2/M2 Three Screen Report. Nielsen Company. Nielsen, M. (2012). Imitation, pretend play, and childhood: Essential elements in the evolution of human culture? Journal of Comparative Psychology, 126(2), 170–181. https://doi.org/10.1037/a0025168 Novianti, R., Febrialismanto, F., Puspitasari, E., & Hukmi, H. (2020). Meningkatkan pengetahuan orang tua dalam mendidik anak di era digital di Kecamatan Koto Gasib Kabupaten Siak Provinsi Riau [Increasing parental knowledge in educating children in the digital era in Koto Gasib Sub-district, Siak Regency, Riau Province]. Riau Journal of Empowerment, 3(3), 183–190. https://doi.org/10.31258/raje.3.3.183-190 Novianti, R., & Garzia, M. (2020). Penggunaan Gadget pada Anak; Tantangan Baru Orang Tua Milenial[Use of Gadgets in Children; Millennial Parents' New Challenge]. Jurnal Obsesi: Jurnal Pendidikan Anak Usia Dini, 4(2), 1000–1010. Pediatrics, A. A. O. (2016). American Academy of Paediatrics announces new recommendations for children’s media use. Advocacy & Policy. Radesky, J. S., & Christakis, D. A. (2016). Increased Screen Time: Implications for Early Childhood Development and Behaviour. Paediatric Clinics of North America, 63(5), 827–839. https://doi.org/10.1016/j.pcl.2016.06.006 Ransdell, S., Kent, B., Gaillard-Kenney, S., & Long, J. (2011). Digital immigrants fare better than digital natives due to social reliance: Digital immigrants and social reliance. British Journal of Educational Technology, 42(6), 931–938. https://doi.org/10.1111/j.1467-8535.2010.01137.x Rideout, V., &. Robb, M. B., & Robb, M. B. (2020). The commonsense census: Media use by kids aged zero to eight. Common Sense Media. Scott, F. L. (2021). Family mediation of preschool children’s digital media practices at home. Learning, Media, and Technology, 1–16. https://doi.org/10.1080/17439884.2021.1960859 Setianingsih, S. (2018). Dampak penggunaan gadget pada anak usia prasekolah dapat meningkatan resiko gangguan pemusatan perhatian dan hiperaktivitas [The impact of using gadgets on preschool-aged children can increase the risk of attention deficit disorder and hyperactivity]. Gaster, 16(2), 191–205. Sharkins, K. A., Newton, A. B., Albaiz, N. E. A., & Ernest, J. M. (2016). Preschool Children’s Exposure to Media, Technology, and Screen Time: Perspectives of Caregivers from Three Early Childcare Settings. Early Childhood Education Journal, 44(5), 437–444. https://doi.org/10.1007/s10643-015-0732-3 Sheedy, A. J., Brent, J., Dally, K., Ray, K., & Lane, A. E. (2021). Handwriting Readiness among Digital Native Kindergarten Students. Physical & Occupational Therapy In Pediatrics, 41(6), 655–669. https://doi.org/10.1080/01942638.2021.1912247 Steiner-Adair, C., & Barker, T. H. (2013). The Big Disconnect (1st ed.). Harper Collins. Strasburger, V. C., Jordan, A. B., & Donnerstein, E. (2010). Health effects of media on children and adolescents. Pediatrics, 125(4), 756–767. Sugiyono. (2017a). Statistika untuk Penelitian[Statistics for Research]. Alfabeta. Sugiyono, P. (2017b). Metode Penelitian Pendidikan: Pendekatan Kuantitatif, Kualitatif, R&D [Educational Research Methods: Quantitative, Qualitative, R&D Approach]. Cetakan Ke-25. Bandung: CV Alfabeta. Suhana, M. (2018). Influence of Gadget Usage on Children’s Social-Emotional Development. 169(Icece 2017), 224–227. https://doi.org/10.2991/icece-17.2018.58 Sylva, K. (1994). School Influences on Children’s Development. Journal of Child Psychology and Psychiatry, 35(1), 135–170. https://doi.org/10.1111/j.1469-7610.1994.tb01135.x Takeuchi, H., Taki, Y., Hashizume, H., Asano, K., Asano, M., Sassa, Y., Yokota, S., Kotozaki, Y., Nouchi, R., & Kawashima, R. (2016). Impact of videogame play on the brain’s microstructural properties: Cross-sectional and longitudinal analyses. Molecular Psychiatry, 21(12), 1781–1789. Test, J. E., Cunningham, D. D., & Lee, A. C. (2010). Talking With Young Children: How Teachers Encourage Learning. Dimensions of Early Childhood, 38(3), 3–14. Tootell, H., Freeman, M., & Freeman, A. (2014). Generation Alpha at the Intersection of Technology, Play and Motivation. 2014 47th Hawaii International Conference on System Sciences, 82–90. https://doi.org/10.1109/HICSS.2014.19 Twenge, J. M. (2017). IGen: Why today’s super-connected kids are growing up less rebellious, more tolerant, less happy—And completely unprepared for adulthood—And what that means for the rest of us. Simon and Schuster. UNESCO. (2014). Information and Communication Technology (ICT) In Education in Asia. Information Papers, 6(22), 6. UNICEF. (2017). UNICEF for Every Child. The State of The World’s Children 2017. Children in a Digital World. Valkenburg, P. M., Peter, J., & Schouten, A. P. (2006). Friend Networking Sites and Their Relationship to Adolescents’ Well-Being and Social Self-Esteem. CyberPsychology & Behavior, 9(5), 584–590. ht

L'échographie est aujourd'hui une technique d'imagerie de diagnostic répandue. Si l'imagerie dite ‘classique' basée sur la réponse linéaire des tissus est couramment utilisée, l'imagerie harmonique, basée sur la réponse non linéaire des tissus, est maintenant aussi utilisée en routine clinique. L'estimation du paramètre de non linéarité d'un milieu par une technique ultrasonore amène de nouvelles perspectives en termes d'imagerie et de diagnostic. Cependant, la méthode de mesure du paramètre de non linéarité est limitée par deux facteurs, la présence du speckle et la concentration de l'énergie à une profondeur donnée (la zone focale). Cette thèse a pour objectifs de répondre aux deux limitations mentionnées précédemment en proposant de nouvelles méthodes de lissage de l'image pour réduire le speckle et d'améliorer l'estimation du paramètre de non linéarité en mode écho par de nouvelles méthodes d'émission. Dans un premier temps, il a été proposé d'utiliser une méthode de filtrage spatiale basée sur des filtres orthogonaux (filtres de Thomson) lors de la formation de voie en réception pour lisser le speckle. Ce filtrage spatiale intervient après la transmission d'ondes planes sous différents angles pour améliorer la résolution spatiale et le contraste tout en accélérant la cadence d'imagerie. Dans un deuxième temps, l'estimation du paramètre de non linéarité est faite avec une méthode comparative. Le champ de pression du second harmonique d'une zone de référence est comparé avec le champ de pression d'une zone dont le paramètre de non linéarité est inconnu. Cependant, dans le cas des images échographiques, le champ de pression du second harmonique n'est pas accessible. Nous faisons l'hypothèse que la pression acoustique locale est liée à l'intensité de l'image échographique si le speckle est réduit et lissé. La transmission d'ondes planes et l'application de filtres orthogonaux permet de mieux délimiter le paramètre de non linéarité par rapport à une transmission focalisée
Nowadays, ultrasound imaging is a common diagnostic tool thanks to its non-invasive behavior and relatively cheap equipment. Classic medical echographic imaging is based on the linear response of the biological tissue. However harmonic imaging, based on the harmonic frequencies generated by the nonlinear properties of the tissue, is more and more used for clinical application. The quantification of nonlinearity is based on the evaluation of the nonlinearity parameter which strongly influences the harmonics generation. The nonlinearity parameter estimation using an echographic approach would bring new modalities for imaging and diagnosis. However the echographic method for nonlinearity estimation is limited by two factors: the presence of speckles in the image and the focalization used during transmission, which concentrates the energy at one particular depth. The objectives of this thesis work are developing novel approaches to reduce the speckle noise using original smoothing techniques and improving the nonlinearity parameter estimation in echo mode using new transmission-reception strategies. Firstly, new speckle noise reduction approaches were investigated. The Thomson’s multitaper approach was proposed, consisting in using several different orthogonal apodizations during beamforming. This method was combined to a coherent plane-wave compounding transmission-reception strategy improving the spatial resolution and the contrast while improving the frame rate. In a second time, the nonlinearity parameter was estimated using a comparative method. The second-harmonic pressure field of a reference area was compared to the pressure field of an area where the nonlinearity parameter is unknown. However in echo-mode, the pressure field of the medium is unknown. It is assumed in this thesis work that the local pressure can be derived from envelope image local amplitude if the speckle noise is smoothed. The nonlinearity parameter estimation has been improved using plane-wave transmission and orthogonal apodizations compared to the use of a single focalization transmission
Oggigiorno, le tecniche di imaging ad ultrasuoni sono un comune strumento di diagnosi, grazie alla loro non invasività e alla relativa economicità dei sistemi. La risposta lineare dei tessuti biologici è la base per le tecniche di imaging ecografico tradizionali. La generazione di frequenze ad armoniche superiori da parte dei tessuti può essere sfruttata per sviluppare tecniche di imaging innovative (i.e., imaging armonico), che sono sempre più utilizzate per applicazioni cliniche. Tali tecniche sono basate sul metodo di valutazione del parametro di non linearità che influenza fortemente la generazione delle armoniche all’interno dei tessuti. I metodi per la stima dei suddetti parametri sfruttano solitamente un approccio ecografico tradizionale. Di conseguenza, gli effetti legati alla focalizzazione impiegata durante la trasmissione, che concentra l’energia ad una particolare profondità, e la presenza di speckle nell’immagine finale, rendono più incerta la stima del parametro di non linearità. In questa tesi sono proposti metodi innovativi finalizzati a due scopi: ridurre, nelle immagini, il rumore dovuto a speckle, tramite l’adozione di nuove tecniche di smoothing; migliorare la stima dei parametri di non linearità, tramite l’impiego di nuove strategie di beamforming in trasmissione e ricezione. Per ridurre il rumore dovuto a speckle, è stato proposto un approccio di filtraggio spaziale basato sull’impiego dei filtri di Thomson. Tale tecnica consiste nell’impiego di numerose apodizzazioni ortogonali fra di loro in fase di beamforming. Il metodo è stato in particolare combinato con la tecnica di imaging coherent plane-wave compounding, con lo scopo di migliorare la risoluzione spaziale e il contrasto e, al contempo, incrementare il frame rate. Il parametro di non linearità è stato misurato tramite un approccio comparativo. Il campo di pressione della seconda armonica in un’area di riferimento dell’immagine è stato confrontato con quello di un’area in cui il parametro di non linearità è ignoto. In questa tesi, grazie alla riduzione del rumore speckle, è stato possibile assumere che il campo di pressione