Browsing by Subject "tone"
Now showing items 1-5 of 5
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(2009)The purpose of this study was to investigate the usability of aerial images and Landsat TM in estimating Scots pine defoliation. Estimation methods tested were unsupervised classification, maximum likelihood method, mixed model and linear regression model. Image features for needle loss detection were selected with stepwise linear regression and mixed model technique. As a part of the study the relationship between needle loss and leaf area index (LAI) was examined. The relationship between image features, needle loss and leaf area index was also examined. Numerical aerial images and Landsat TM satellite images were used. Textural features were calculated from aerial images and spectral vegetation indices from the satellite image. The study site was located in Ilomantsi, Finland. 71 field sample plots were measured and located with GPS. Field plots were circular plots. Trees with diameter brest height (dbh) over 13,9 cm were measured from 13 meter radius and trees with dbh 5,0 - 13,8 cm were measured from 7 meter radius. Needle loss of all pines was estimated. Needle loss for the plot was calculated as an average weighted by tree height. Four different class combinations were tested in classification. Plots were divided in 2, 3, 4 and 9 classes depending on their needle loss. Different image feature combinations and classification methods were tested. Classification was done by cross validation. Classification results were compared with original classes. The reliability of the classification was tested using accuracy matrix and kappa value. A mixed model was also used for aerial image features. The best image feature combination with all classification methods was the aerial image feature combination selected with stepwise selection method. Both spectral and textural features were included in the stepwise selection result. Classification accuracy varied between 38,0 % (9 classes) and 88,7 % (2 classes). The best explanatory variable for needle loss was the aerial image NIR channel maximum radiation (r2=0,69). However, unsupervised and supervised classification might have produced too positive results because of correlation in the data. Mixed model technique was used to select the variables for the linear model. Mixed model was used to reduce the effects of the correlation. The model classification accuracy varied between 35,2 % (9classes) and 87,3 % (2classes). According to mixed model selection result no textural features were significant predictors for needle loss. Classification results with Landsat image features were slightly poorer than with the best aerial image feature set (accuracy between 25,4 % and 88,7 %). The relationship between needle loss and LAI was poor (r2=0,27). Needle loss and LAI also correlated with different image features. LAI correlated slightly better with textural features than needle loss. Spectral vegetation indices calculated from Landsat TM correlated moderately with both needle loss and LAI. Indices VI3 (r2=0,56), MIR/NIR (r2=0,51) and RSR (r2=0,44) had the strongest connection to needle loss. Spectral vegetation indices could be a potential way for large area needle loss detection.
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(2021)This thesis investigates the interaction between lexical tones and pitch reset in Akan, a Kwa language with about 8.1 million native speakers in Ghana (Eberhard et al., 2020). Experimental studies on Akan prosody are limited, although the language has a large first and second language speakers. This study seeks to increase our knowledge of the tone-intonation structure of the Akan language. In an earlier study on Akan complex declarative sentences, pitch reset occurred at the beginning of the content word that followed the clausal marker of an embedded clause (Kügler, 2016). Following a pilot study, a hypothesis was formed for the present study that pitch reset in complex declarative utterances in Akan also occurs within the clausal marker of the dependent clause and not only in the following content word. Focusing on the Asante Twi dialect, a controlled material consisting of 64 complex sentences were created. Five native speakers of Asante Twi were recorded as they produced the 64 sentences and additional 32 complex sentences used as fillers. The Mean f_0 values of the syllables of the subordinate conjunction and the syllables of the word before and after the conjunction were extracted and analysed in R; the statistical analysis was based on a linear mixed model. As expected, a reset in the pitch contour consistently occurred within the subordinate conjunction, contrasting the earlier study. The conjunction was phrased prosodically with the dependent clause to signal the syntactic relationship between the two. The degree of pitch register reset was also dependent on the tonal structure; reset was more significant when the initial tone of the conjunction was High but lesser when the conjunction began with a Low tone. Thus, the results show that lexical tones interact to determine the f_0 contour of Akan utterances and that the intonational contour of utterances is complex in the Akan language.
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(2021)This thesis investigates the interaction between lexical tones and pitch reset in Akan, a Kwa language with about 8.1 million native speakers in Ghana (Eberhard et al., 2020). Experimental studies on Akan prosody are limited, although the language has a large first and second language speakers. This study seeks to increase our knowledge of the tone-intonation structure of the Akan language. In an earlier study on Akan complex declarative sentences, pitch reset occurred at the beginning of the content word that followed the clausal marker of an embedded clause (Kügler, 2016). Following a pilot study, a hypothesis was formed for the present study that pitch reset in complex declarative utterances in Akan also occurs within the clausal marker of the dependent clause and not only in the following content word. Focusing on the Asante Twi dialect, a controlled material consisting of 64 complex sentences were created. Five native speakers of Asante Twi were recorded as they produced the 64 sentences and additional 32 complex sentences used as fillers. The Mean f_0 values of the syllables of the subordinate conjunction and the syllables of the word before and after the conjunction were extracted and analysed in R; the statistical analysis was based on a linear mixed model. As expected, a reset in the pitch contour consistently occurred within the subordinate conjunction, contrasting the earlier study. The conjunction was phrased prosodically with the dependent clause to signal the syntactic relationship between the two. The degree of pitch register reset was also dependent on the tonal structure; reset was more significant when the initial tone of the conjunction was High but lesser when the conjunction began with a Low tone. Thus, the results show that lexical tones interact to determine the f_0 contour of Akan utterances and that the intonational contour of utterances is complex in the Akan language.
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(2023)This thesis investigates the realisation of tone in dialects of Southern Angami, a language of Tibeto-Burman family spoken in the state of Nagaland, North-East India. The audio recordings of native speakers are analysed to determine how the tones differ in pitch movement patterns, accounting for context and dialect variation. The research questions concern the significance of pitch contours and duration in a level tone system, as well as tone unit interaction. It was concluded that the fundamental frequency is the main determining factor, and neither pitch contour nor duration have a more prominent effect than pitch value; however, it is possible that duration plays a role in discerning tones 2 and 3, and a pitch curve is a consistent feature of tones 1 and 4. No significant difference was found in tone systems of Jotsoma and Kigwema.
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(2023)This thesis investigates the realisation of tone in dialects of Southern Angami, a language of Tibeto-Burman family spoken in the state of Nagaland, North-East India. The audio recordings of native speakers are analysed to determine how the tones differ in pitch movement patterns, accounting for context and dialect variation. The research questions concern the significance of pitch contours and duration in a level tone system, as well as tone unit interaction. It was concluded that the fundamental frequency is the main determining factor, and neither pitch contour nor duration have a more prominent effect than pitch value; however, it is possible that duration plays a role in discerning tones 2 and 3, and a pitch curve is a consistent feature of tones 1 and 4. No significant difference was found in tone systems of Jotsoma and Kigwema.
Now showing items 1-5 of 5