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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Validity of a New Measure of Phonemic Awareness that Does Not Require Spoken Responses in Children with Complex Communication Needs

Chavers, Tiffany 19 June 2017 (has links)
Children with complex communication needs (CCN) routinely have difficulty attaining appropriate literacy skills. Two indicators of literacy development are the alphabetic principle and phonemic awareness (Byrne & Fielding-Barnsley, 1989). The acquisition of minimal literacy skills such as letter sound knowledge can give children with CCN the opportunity to communicate and generate their own messages, instead of being reliant on vocabulary provided by others. In order to identify appropriate intervention approaches, nonverbal assessments of phonological and phonemic awareness for individuals with CCN are needed. The purpose of this study was to determine the reliability of the Dynamic Assessment of the Alphabetic Principle, as well as determine to what extent the performance of DAAP was associated with other measures of phonological and phonemic awareness and emergent reading skills. The DAAP was administered over the course of one to five session to seven participants with an assortment of developmental and language disorders. In addition to the DAAP, participants were administered a letter-sound knowledge task, a sound matching task that evaluated awareness of first sounds of words and separately evaluated awareness of the last sounds of words (i.e., either sound matching from the Comprehensive Test of Phonological Processing – 2nd edition [CTOPP-2; Wagner, Torgesen, Reshotte, & Pearson, 2013] or initial sound matching and final sound matching from the Phonological and Print Awareness Scale [PPA; Williams, 2014]). The reliability of the DAAP was calculated in two different ways. First, Cronbach alphas were calculated to estimate the reliability of items within subscales and between the subscales. Reliability of the items within each subscale ranged from .96 to .99 and the reliability of the items between each subscale ranged from .87 to .99. Overall the alpha between all four of the subscales was .96. Next, bivariate correlations were calculated between each subscale score. Values ranged from .82 to .99, and all were significant according to bootstrapped 95% confidence intervals that did not contain 0. This information indicated that there was a high degree of internal consistency for the items and the subtests for the DAAP. To evaluate the extent to which performance on the DAAP was associated with other measures of phonemic awareness, Bivariate Pearson correlations with standard significance values and bootstrapped 95% confidence intervals were calculated. The scores on the onset, rime, coda, and vowel subtests of the DAAP were correlated with sound matching first (SM-First), sound matching last (SM-Last) and sound matching chance (SM-chance) variables. The rime subtest of the DAAP was found to be significantly correlated with SM-First variable. Furthermore, the rime and vowel subscales of the DAAP were found to be significantly correlated with SM-Last variable. All four subtests of DAAP were significantly correlated to SM-chance variable. Lastly, to evaluate the performance on the DAAP in association to other measures of emergent reading skills, bivariate Pearson correlations were calculated between the subtests of the DAAP and letter sound knowledge (LSK). Scores on LSK was significantly related to rime, coda, and vowel. The data suggest that the DAAP is a reliable assessment. Furthermore, many conventional measures of phonological awareness and emergent reading skills were significantly correlated with subtests of DAAP. The pattern of the results suggests that the DAAP may be a reliable tool for measuring acquisition of the alphabetic principle in children with CCN.
52

Perceptual Differences in Natural Speech and Personalized Synthetic Speech

Overton, Katherine 28 June 2017 (has links)
The purpose of this study was to determine what perceptual differences existed between a natural recorded human voice and a synthetic voice that was created to sound like the same voice. This process was meant to mimic the differences between a voice that would be used for Message Banking and a voice that would be created by the ModelTalker system. Forty speech pathology graduate students (mean age = 23 years) rated voices on clarity, naturalness, pleasantness, and overall similarity. Analysis of data showed that the natural human voice was consistently rated as more natural, clear, and pleasant. In addition, participants generally rated the two voices as very different. This demonstrates that, at least in terms of perception, using the method of Message Banking results in a voice that is overall perceived more positively than the voice created using ModelTalker.
53

Children’s attitudes toward interaction with an unfamiliar peer with little or no functional speech : comparing high- and low- technology devices

Horn, Tenille January 2014 (has links)
Augmentative and Alternative Communication (AAC) provides many individuals with little or no functional speech (LNFS) with a means to function within their daily environments and lives. AAC comprises the use of either or both unaided (the individual with LNFS‘s body) and aided (high- and low-technology devices) methods for communicating. High-technology non-dedicated devices like the iPad™ with Proloquo2Go have changed the future of augmentative and alternative communication. This study aimed to determine and compare the attitudes of typically developing children towards an unfamiliar peer with LNFS who uses a high-technology nondedicated communication device, namely the iPad™ with Proloquo2Go (Video 1), and the same unfamiliar peer with LNFS using a low-technology communication board (Video 2). Seventy-eight (78) children between the ages of 9; 00 -12; 11, participated in the study. The participants were divided into two groups and a 2 x 2 crossover design was utilized. Group 1 was required to watch two videos in a specific sequence, one video of an unfamiliar peer with LNFS communicating with the high-technology non-dedicated iPad™ with Proloquo2Go, followed by a video of the same unfamiliar peer with LNFS in a communication interaction using a low-technology communication board. Participants were required to complete a Communication Aid/Device Attitudinal Questionnaire (CADAQ) after viewing each video. Participants in Group 2 watched the same videos in an alternating sequence in order to counterbalance effects of order. Results revealed that the video of the unfamiliar peer with LNFS using the iPad™ with Proloquo2Go was perceived more positively by the participants within certain dimensions of the CADAQ and the possible reasons are described. This is followed by a critical evaluation of the study and recommendations for future research. / Dissertation (MA)--University of Pretoria, 2014. / gm2014 / Centre for Augmentative and Alternative Communication (CAAC) / Unrestricted
54

Biological studies on the lepidopteran egg parasitoid Trichogrammatoidea lutea Girault (Hymenoptera : Trichogrammatoidae) at various temperatures

Mawela, Khethani Vincent 16 May 2011 (has links)
The African bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), is a polyphagous pest that attacks many crops in sub-Saharan Africa. The pest is currently managed through chemical control, and by planting Bt-transgenic cotton. Trichogrammatoidea lutea Girault (Hymenoptera: Trichogrammatidae) is an indigenous egg parasitoid of H. armigera in southern Africa. The study was undertaken to determine the potential of T. lutea as a biological control agent for augmentative releases as an alternative to chemical control, and to pave the way for the development of a mass-rearing method. The biology of T. lutea was examined in the laboratory on H. armigera, Chilo partellus (Swinhoe), and Cadra (formerly Ephestia) cautella (Walker) (Lepidoptera: Pyralidae). The objectives of the study were to determine (i) the exposure time of UV-irradiation required for killing the embryos of the hosts and the effect of UV-irradiated eggs on life history parameters of T. lutea, (ii) which host(s) and temperature(s) (18, 21, 24, 27, 30 and 35 °C) are suitable for mass-rearing of T. lutea, and (iii) the longevity and age-related reproductive biology of T. lutea on H. armigera. Findings of this study showed that 13 minutes of UV-irradiation were sufficient to kill embryos of all three host species. Life history parameters were not influenced by UV-irradiation but by host species. Parasitism, number of progeny per parasitized egg, proportion of females, and developmental time of T. lutea aried on different host species at temperatures ranging from 18 to 30 °C. Trichogrammatoidea lutea did not develop at 35 °C. Overall parasitism by T. lutea was higher on H. armigera and Cadra cautella compared to Chilo partellus. The number of progeny per parasitized egg was highest on H. armigera compared to Cadra cautella and Chilo partellus. The proportion of females was highest on Chilo partellus, intermediate on Cadra cautella, and lowest on H. armigera. For all species and temperatures tested, parasitism and number of progeny per parasitized egg by T. lutea was highest on H. armigera at 27 °C. The lower threshold for development of T. lutea on all hosts was approximately 12 °C. Female T. lutea parasitized eggs of H. armigera soon after eclosion, with the highest parasitism achieved on the day of eclosion. Though T. lutea parasitized eggs for up to 14 days, it may not be economically viable to keep them in cultures for more than three days since progeny became male biased three days after eclosion. The average longevity of female and male T. lutea was 9 and 6 days, respectively. The life table parameters of T. lutea, the net replacement rate (Ro), mean generation time (T), and instantaneous rate of population increase (rm) were 25.5, 9.79, and 0.33, respectively. The timing of inundative releases of T. lutea must be synchronised with the time that eggs of H. armigera are abundant in the field. The results of this study indicate that T. lutea is a good candidate for further testing for augmentative biological control of H. armigera in the field. If successful, T. lutea may provide opportunities for expanding tactics in the management of H. armigera in southern Africa. Copyright / Dissertation (MSc)--University of Pretoria, 2011. / Zoology and Entomology / unrestricted
55

The effect of sequential exposure of colour conditions on rate and accuracy of graphic symbol location

Kolatsis, Anna 12 February 2009 (has links)
There has been limited research done to determine the impact of the use of colour on communication displays in the facilitation of graphic symbol location within an overlay. As many Augmentative and Alternative Communication systems are pictorial in nature, it is of importance that interventionists are aware of the potential impact that colour can have on the accuracy and rate of symbol location. The present study is based on a study by Wilkinson, Carlin and Jagaroo (2006) and used the same testing material (colour conditions) whilst modifying the type of exposure to these colour conditions. This study investigated the effect of sequential exposure of colour conditions on the rate and accuracy of graphic symbol location. The study used a comparative, non-experimental group design using sixty participants who conformed to specific selection criteria. Each participant was exposed to three colour conditions that were placed in a specific sequential order. The participants were required to match a target, graphic symbol within an array of symbols in the differing colour conditions. Two different types of graphic symbols were used meaningful (Type A) and arbitrary (Type B). Two different colour sets were also used with the colour conditions varying in each set. Set 1 were the sequentially ordered colour conditions of same colour, mixed colour and unique colour symbols (difficult to easy) while Set 2 were the sequentially ordered colour conditions of unique colour, mixed colour and same colour symbols (easy to difficult). The major findings of the study were as follows. In terms of rate, there was a significant interaction noted between the two symbol types and their sequential ordering. The time taken (rate) for the location of the nonreferential forms was slower than that taken for the meaningful symbols. The reasoning behind this result could be that the non-referential forms were not as familiar to the participants as the meaningful symbols were. Thus, the rate recording of the meaningful symbols and the non-referential forms described in the three colour conditions was different and could be noted in the results. In terms of accuracy, a significant impact was noted between the two symbol types when the first manner of sequential ordering was used, however, there were no significant differences noted when the second manner of sequential ordering was used. This implies greater accuracy was recorded when the second manner of sequential ordering was used as this ordering appeared to be “visually easier” for the location of symbols. / Dissertation (MA)--University of Pretoria, 2009. / Centre for Augmentative and Alternative Communication / unrestricted
56

The iconicity and learnability of selected picture communication symbols : a study on Afrikaans-speaking children

Basson, Hester Magdalena 04 October 2005 (has links)
Everyday communication occurs mostly through speech, thus learners who have little or no functional speech (LNFS) need to augment their communication by using additional communication strategies to ensure that they are able to participate in the interaction process. The use of Augmentative and Alternative Communication (AAC) can and should play an important role in assisting learners with LNFS to access information and services and to communicate. Graphic symbols form an important part of most AAC users’ communication systems. Therefore studies which focus on increasing understanding of the way different graphic symbols are learnt and retained by children and adults, are pivotal for a better understanding of the processes involved in graphic symbol learning. Iconicity and learnability of symbols are two important factors to consider when choosing an appropriate graphic symbol set/system. The purpose of the current study was to determine how accurately typically developing urban, 6-year-old Afrikaans-speaking children could firstly, identify 16 PCS presented thematically on a commercially available communication overlay, and secondly, recognize these symbols following exposure to a learning experience. Forty-six participants, divided into 2 cohorts, were each presented with 16 copies of a 16-matrix overlay and required to match a symbol with a spoken Afrikaans label. The participants were then divided into two groups, one group receiving training in the meaning of the symbols and the other group receiving no training. Finally the test-procedure was repeated with the cohorts. The results indicated that the 16 PCS symbols had an iconicity of between 12.5 % (accuracy score > 50 %) and 25 % (accuracy score > 75 %) for the combined group. Results further indicated a significant improvement in both the experimental and the control groups’ post-test results. The significant difference between the two groups’ post-test results does, however, indicate that the experimental group recognized more symbols during the post-test administration than the control group and they had thus benefited from the training session. The control group’s better post-test results can be attributed to the single exposure through the pre-test procedure. The participants made use of the information afforded them by the postural cues implying motion. They did not, however, make full use of the arrow cues or the direction of the arrows, which also implied motion. Once the participants of the experimental group were made aware of the arrows, they seemed to use the information the arrows offered to help them remember the symbol meanings during the post-test procedure. Copyright 2004, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Basson, HM 2004, The iconicity and learnability of selected picture communication symbols : a study on Afrikaans-speaking children, MA dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-10042005-155306/ > / Dissertation (M (Alternative and Augmentative Communication))--University of Pretoria, 2006. / Centre for Augmentative and Alternative Communication / unrestricted
57

Advanced Augmentative and Alternative Communication System Based in Physiological Control

Díaz Pineda, Jaime Alberto 03 November 2017 (has links)
Dyskinetic Cerebral Palsy (DCP) is mainly characterized by alterations in muscle tone and involuntary movements. Therefore, these people present with difficulties in coordination and movement control, which makes walking difficult and affects their posture when seated. Additionally, their cognitive performance varies between being completely normal and severe mental retardation. People with DCP were selected as the objective of this thesis due to their multiple and complex limitations (speech problems and motor control) and because their capabilities have a great margin for improvement thanks to physiological control systems. Given their communication difficulties, some people with DCP have good motor con-trol and can communicate with written language. However, most have difficulty using Augmentative and Alternative Communication (AAC) systems. People with DCP gen-erally use concept boards to indicate the idea they want to communicate. However, most communication solutions available today are based on proprietary software that makes it difficult to customize the concept board and this type of control system. This is the motivation behind this thesis, with the aim of creating an interface with characteristics, able to be adapted to the user needs and limitations. Thus, this thesis proposes an Augmentative and Alternative Communication System for people with DCP based on physiological control. In addition, an innovative system for direct con-trol of concept boards with EMG is proposed. This control system is based on a physi-cal model that reproduces the muscular mechanical response (stiffness, inertia and viscosity). It allows for a selection of elements thanks to small pulses of EMG signal with sensors on a muscle with motor control. Its main advantage is the possibility of correcting errors during selection associated with uncontrolled muscle impulses, avoid-ing sustained muscle effort and thus reduced fatigue. / La Parálisis Cerebral de tipo Discinésica (DCP) se caracteriza principalmente por las alteraciones del tono muscular y los movimientos involuntarios. Por ello, estos pacientes presentan dificultades en la coordinación y en el control de movimientos, lo cual les dificulta el caminar y afecta su postura cuando están sentados. Cabe resaltar que la capacidad cognitiva de las personas con DCP puede variar desde completamente normal, hasta un retraso mental severo. Las personas con DCP han sido seleccionadas como objetivo de esta tesis ya el margen de mejora de sus capacidades es amplio gracias a sistemas de control fisiológico, debido a sus múltiples y complejas limitaciones (problemas de habla y control motor). Debido a sus dificultades de comunicación, algunas personas con DCP se pueden comunicar con lenguaje escrito, siempre y cuando tenga un buen control motor. Sin embargo, la mayoría tienen dificultades para usar sistemas de Comunicación Aumentativos y Alternativos (AAC). De hecho, las personas con DCP utilizan generalmente tableros de conceptos para indicar la idea que quieren transmitir. Sin embargo, la mayoría las soluciones de comunicación disponibles en la actualidad están basadas en software propietario que hacen difícil la personalización del tablero de conceptos y el tipo de sistema de control. Es aquí donde surge esta tesis, con el objetivo de crear una interfaz con esas características, capaz de adaptarse a las necesidades y limitaciones del usuario. De esta forma, esta tesis propone un sistema de comunicación aumentativo y alternativo para personas con DCP basado en control fisiológico. Además, se propone un Sistema innovador de control directo sobre tableros de conceptos basado en EMG. Este Sistema de control se basa en un modelo físico que reproduce la respuesta mecánica muscular (basado en parámetros como Rigidez, Inercia y Viscosidad), permitiendo la selección de elementos gracias a pequeños pulsos de señal EMG con sensores sobre un músculo con control motor. Sus principales ventajas son la posibilidad de corregir errores durante la selección asociado a los impulsos musculares no controlados, evitar el esfuerzo muscular mantenido para alcanzar un nivel y reducir la fatiga. / La Paràlisi Cerebral de tipus Discinèsica (DCP) es caracteritza principalment per les alteracions del to muscular i els moviments involuntaris. Per açò, aquests pacients presenten dificultats en la coordinació i en el control de moviments, la qual cosa els dificulta el caminar i afecta la seua postura quan estan asseguts. Cal ressaltar que la capacitat cognitiva de les persones amb DCP pot variar des de completament normal, fins a un retard mental sever. Les persones amb DCP han sigut seleccionades com a objectiu d'aquesta tesi ja el marge de millora de les seues capacitats és ampli gràcies a sistemes de control fisiològic, a causa dels seus múltiples i complexes limitacions (problemes de parla i control motor). A causa de les seues dificultats de comunicació, algunes persones amb DCP es poden comunicar amb llenguatge escrit, sempre que tinga un bon control motor. No obstant açò, la majoria tenen dificultats per a usar sistemes de Comunicació Augmentatius i Alternatius (AAC). De fet, les persones amb DCP utilitzen generalment taulers de conceptes per a indicar la idea que volen transmetre. No obstant açò, la majoria les solucions de comunicació disponibles en l'actualitat estan basades en programari propietari que fan difícil la personalització del tauler de conceptes i el tipus de sistema de control. És ací on sorgeix aquesta tesi, amb l'objectiu de crear una interfície amb aqueixes característiques, capaç d'adaptar-se a les necessitats i limitacions de l'usuari. D'aquesta forma, aquesta tesi proposa un sistema de comunicació augmentatiu i alternatiu per a persones amb DCP basat en control fisiològic. A més, es proposa un sistema innovador de control directe sobre taulers de conceptes basat en EMG. Aquest sistema de control es basa en un model físic que reprodueix la resposta mecànica muscular (basat en paràmetres com a Rigidesa, Inèrcia i Viscositat), permetent la selecció d'elements gràcies a xicotets polsos de senyal EMG amb sensors sobre un múscul amb control motor. Els seus principals avantatges són la possibilitat de corregir errors durant la selecció associat als impulsos musculars no controlats, evitar l'esforç muscular mantingut per a aconseguir un nivell i reduir la fatiga. / Díaz Pineda, JA. (2017). Advanced Augmentative and Alternative Communication System Based in Physiological Control [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/90418 / TESIS
58

The Impact of Smart Home Technology on Independence for Individuals Who Use Augmentative and Alternative Communication

Corso, Christina L. 10 September 2021 (has links)
No description available.
59

The effect of frequency of augmented input on the auditory comprehension of narratives for persons with Wernicke’s aphasia

Leuvennink, Jacqueline Lisinda January 2019 (has links)
Augmented input refers to the support of any form of linguistic or visual strategies to enhance understanding during intervention. Previous research predominantly focused on the various types of augmented input that can be used, especially to support reading comprehension. The purpose of this study was to determine and compare the effect of varying amounts of augmented input using partner-pointing on the accuracy of auditory comprehension for persons with Wernicke’s aphasia specifically. The research was conducted with seven participants with Wernicke’s aphasia. The participants listened to three narratives in three conditions, namely 0%, 50% and 100% augmented input with partner-pointing, and then responded to comprehension items based on the narratives. Most participants had more accurate scores during the 50% augmented input condition. In addition, participants did significantly better in the 50% condition than in the 100% augmented input condition. The main clinical implication is that supporting narrative auditory comprehension with augmented input, used as pre-task and during-task stimulation, seems to facilitate the improved auditory comprehension of narratives for some persons with Wernicke’s aphasia. However, providing augmented input for all the content units of a narrative seems to have a negative effect on the auditory comprehension of some persons with Wernicke’s aphasia. Continued research is necessary to determine what types and frequency of augmented input will lead to improved auditory comprehension for persons with aphasia, specifically Wernicke’s aphasia. / Dissertation (MA)--University of Pretoria, 2019. / Centre for Augmentative and Alternative Communication (CAAC) / MA / Unrestricted
60

Effects of varied dosage of aided input on following directives that contain prepositions for children with Autism Spectrum Disorder (ASD)

Hassim, Rafeeyah January 2019 (has links)
Background: Some children with ASD have comprehension difficulties that affect their ability to follow directives that contain prepositions. Aided input has been known to facilitate improved comprehension skills when spoken language is used with graphic symbols. Aims: This study examined the effects that aided input presented at two levels (20% of aided input and 60% of aided input) has on children with ASD’s following of directives that contain prepositions. Methods: An experimental, within-subjects crossover design was utilised where all participants were exposed to each treatment condition at a different time period. Altogether 21 participants between 5.0 and 11.11 years of age were asked to follow 12 directives using aided input at two conditions. Participants first completed a pre-test task to confirm their noun knowledge, preposition knowledge and matching skills. Participants were described based on the CARS classification and their PPVT-4 scores. The effects of the aided input were measured and compared based on the accuracy of responses. Results: Descriptive statistics were used to describe the data, and multivariate analysis was used to analyse the data. Some children with ASD (n=9) who received a higher level of aided input (60%) were able to respond more accurately than those who received a lower level of aided input (20%). However, some children with ASD (n=4) responded more accurately to the lower level of aided input (20%) than the higher level of aided input (60%). Some children with ASD (n=5) responded in the same manner for both levels of aided input and some children with ASD (n=3) did not respond at all despite the level of aided input. The results showed no statistically significant difference between the higher (60%) and lower (20%) levels of aided input. Conclusion: It was concluded that the 60% aided input level yielded a higher accuracy of responses than the 20% aided input level in some children with ASD. In addition, the results suggest that augmenting spoken language was advantageous in some children with ASD. However, further research is needed to better describe the effects of aided input, using graphic symbols. Future research directions are suggested. / Dissertation (MA)--University of Pretoria, 2019. / Centre for Augmentative and Alternative Communication (CAAC) / MA / Unrestricted

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