Dissertations / Theses on the topic 'Mean length of utterances'

Data for this study were derived from videotapes of 26 father-infant dyads, specifically from a five minute period of free-play. The first step was the creation of a literal transcription of the father-infant dyads interaction. Subsequently, nine variables of fathers' language characteristics and one infant characteristic were coded employing the literal transcriptions and observing the videotapes. The fathers' language variables were number of : (1) father utterances, (2) father words, (3) father contingent responses, (4) father teaching utterances, (5) father descriptive teaching utterances, (6) father directive teaching utterances - making commands, (7) father directive teaching utterance  asking questions, (8) percentage of father teaching utterances, and (9) mean length of father utterances (MLU). The infant variable was number of vocalizations. Eight out of the nine variables were positively correlated to infant vocalizations, indicating the importance of fathers input in child language development. The only negative correlation in the present study was between Mean Length of Utterance (MLU) and infant vocalizations and the possible reasons are discussed. The findings support the idea that there are positive relationships between fathers' language characteristics and infant vocalizations. Recommendations are made that fathers should be involved in early intervention programs.
M.A.
Department of Child, Family and Community Sciences
Education
Early Childhood Development and Education MS

Factors influencing language development and use are many. Teacher influences such as teacher:child ratio and teaching experience can affect the types of language children produce. Classroom influences including activities , size of the room, and length of the day also play a role in the development of language. All of these areas need to be considered in order to provide the best possible language environment for the preschool child. In this study, the researchers examined the mean length of utterance (MLU) values of preschool children while participating at three areas in a preschool classroom : art, dramatic play, and snack. Gender differences in MLU were also studied. Sixteen children (8 females, 8 males), ranging in age from 50 to 66 months, participated in the study . The children were currently attending the Child Development Laboratory at Utah State University. For the collection of data , the children wore a tape recorder with a microphone until a 5-minute sample from each of the areas was obtained . These audio recordings were then transcribed and calculated into MLU values. Findings from the analysis of variance tests (3[activity : art , dramatic p l ay, snack] X 2 [gender: male , female]) demonstrated that the children had larger MLU values at snack than at art or dramatic play. Snack time has not always been recognized as an activity area for young children to display typical language use. Overall , and at the three individual areas , there were no gender differences found in MLU. Results of this study may be used in planning how to arrange and organize an environment in which the children are comfortable and have opportunities to converse with both adults and other children.

Mean length of utterance (MLU) is widely used in child language sample analysis as a way to quantify language development. The current study examines the split-half reliability of MLU and two alternative measures: MLU2 and median length of utterance (MdLU). The effects of utterance segmentation into phonological units (P-units) or communication units (C-units) on reliability were also studied. Sixty conversational child language samples were used which included ten children with language impairment. All measures were found to have high levels of split-half reliability, with MLU and MLU2 having higher levels of reliability than MdLU. There was no significant difference between MLU and MLU2. The differences in reliability when segmented into P-units or C-units were inconsistent. Overall, MLU and MLU2 are adequately reliable measures for clinical use.

Developmental Sentence Scoring (DSS) is a standardized language sample analysis procedure that uses complete sentences to evaluate and score a child’s use of standard American-English grammatical rules. Automated DSS software can potentially increase efficiency and decrease the time needed for DSS analysis. This study examines the accuracy of one automated DSS software program, DSSA Version 2.0, compared to manual DSS scoring on previously collected language samples from 30 children between the ages of 2;5 and 7;11 (years;months). The overall accuracy of DSSA 2.0 was 86%. Additionally, the present study sought to determine the relationship between DSS, DSSA Version 2.0, the mean length of utterance (MLU), and age. MLU is a measure of linguistic ability in children, and is a widely used indicator of language impairment. This study found that MLU and DSS are both strongly correlated with age and these correlations are statistically significant, r = .605, p < .001 and r = .723, p < .001, respectively. In addition, MLU and DSSA were also strongly correlated with age and these correlations were statistically significant, r = .605, p < .001 and r = .669, p < .001, respectively. The correlation between MLU and DSS was high and statistically significant r = .873, p < .001, indicating that the correlation between MLU and DSS is not simply an artifact of both measures being correlated with age. Furthermore, the correlation between MLU and DSSA was high, r = .794, suggesting that the correlation between MLU and DSSA is not simply an artifact of both variables being correlated with age. Lastly, the relationship between DSS and age while controlling for MLU was moderate, but still statistically significant r = .501, p = .006. Therefore, DSS appears to add information beyond MLU.

Dissertação de Mestrado em Desenvolvimento e Perturbações da Linguagem na Criança
A Extensão Média do Enunciado (EME) é um índice que resulta do rácio entre o número de morfemas (EME-m) ou número de palavras (EME-p) e o número de enunciados produzidos pela criança. Este índice tem vindo a ser estudado e utilizado em diferentes países e línguas, e, apesar de muitos estudos o apontarem como um bom indicador de desenvolvimento gramatical e linguístico, outros são controversos, principalmente quando aplicados a línguas com morfologia flexional mais rica, como o caso do português. Dada a escassez de dados para o português europeu, confinados a duas faixas etárias, e atendendo às evidências de que a EME-m e a EME-p apresentam uma boa correlação, neste estudo procurou-se analisar a EME-p, dos três aos sete anos. Os principais objetivos da presente dissertação são verificar se a EME-p será um bom indicador de desenvolvimento gramatical e linguístico, através da sua correlação com a idade e analisando diferenças entre faixas etárias, entre contextos de discurso (narrativo e espontâneo) e o nível de escolaridade (pré-escolar e escolar). Participaram no estudo cinquenta crianças, monolingues do português europeu e com desenvolvimento típico de linguagem, a frequentar centros educativos do Concelho de Santa Comba Dão. Foram gravadas, em dois momentos, amostras de discurso, espontâneo e narrativo, perfazendo, pelo menos, cem enunciados, que, posteriormente, foram transcritos através do Software Computerized Language Analysis (CLAN), que também realizou, de forma automática, o cálculo da EME-p. Os resultados indicam uma associação forte entre a idade e a EME-p, apesar de não existirem diferenças entre todas as faixas etárias, e uma correlação positiva entre a EME-p e o desenvolvimento da linguagem de crianças monolingues do português europeu. O valor da EME-p em discurso narrativo é estatisticamente superior ao seu valor em discurso espontâneo e o grupo em idade pré-escolar apresentou menor desempenho do que o grupo escolar. Em suma, considera-se que a EME-p pode fornecer informação pertinente sobre o desenvolvimento expressivo morfossintático da criança, contudo não poderão ser considerados valores padrão nem se poderá utilizar este índice como critério de diagnóstico.
The Mean Length of Utterance (MLU) is an index that results from the ratio between the number of morphemes (MLUm) or number of words (MLUw) and the number of utterances produced by the child. This index has been studied and used in different countries and languages and although many studies tell us that it is a good grammatical and linguistic development indicator, others are controversial, especially when applied to languages with richer inflectional morphology, such as Portuguese. Given the lack of data for European Portuguese confined to two age groups, and given the evidence that MLUm and MLUw have a good correlation, in this study we tried to analyze the MLUw in a group from three to seven years old. The main objectives of this dissertation are to check if the MLUw is a good indicator of grammatical and linguistic development, verifying its correlation with age and analyzing differences between age groups, discourse contexts (narrative and spontaneous) and the level of education (pre -school and school-age). In this study participated fifty children. They all were monolingual speakers of European Portuguese with typical language development, attending educational centers of the municipality of Santa Comba Dão. Speech samples were recorded in two different moments, in spontaneous speech and narrative context, making at least an hundred utterances which were later transcribed through Computerized Language Analysis Program (CLAN) which also calculated automatically the MLUw. The results indicate a strong association between age and the MLUw, although there are no significant differences between all age groups, and a positive correlation between MLUw and the development of European Portuguese children. The value of the MLUw in narrative discourse is statistically higher than in spontaneous speech and the group of pre-school age showed lower performance than the school-age group. In short, it is considered that the MLUw can provide relevant information on child development of morphosyntactic expressive competence, but cannot be considered as normative data or for diagnostic criterion.

This paper studies the interval estimation of three discrete distributions: thebinomial distribution, the Poisson distribution and the negative-binomialdistribution. The problem is the chaotic behavior of the coverage probabilityfor the Wald interval. To solve this problem, alternative confidence intervals areintroduced. Coverage probability and expected length are chosen to be thecriteria evaluating the intervals.In this paper, I firstly tested the chaotic behavior of the coverageprobability for the Wald interval, and introduced the alternative confidenceintervals. Then I calculated the coverage probability and expected length forthose intervals, made comparisons and recommended confidence intervals forthe three cases. This paper also discussed the relationship among the threediscrete distributions, and in the end illustrated the applications on binomialand Poisson data with brief examples.

A variety of tools have been developed to assist in the quantification and analysis of naturalistic language samples. In recent years, computer technology has been employed in language sample analysis. This study compares a new automated index, Scoring Sentences Developmentally (SSD), to two existing measures. Eighty samples from three corpora were manually analyzed using DSS and MLU and the processed by the automated software. Results show all three indices to be highly correlated, with correlations ranging from .62 to .98. The high correlations among scores support further investigation of the psychometric characteristics of the SSD software to determine its clinical validity and reliability. Results of this study suggest that SSD has the potential to compliment other analysis procedures in assessing the language development of young children.

For data-limited fisheries, length-based mortality estimators are attractive as alternatives to age-structured models due to the simpler data requirements and ease of use of the former. This dissertation develops new extensions of mean length-based mortality estimators and applies them to federally-managed stocks in the southeastern U.S. and U.S. Caribbean. Chapter 1 presents a review of length-based methods from the literature. Common themes regarding the methodology, assumptions, and diagnostics in these length-based methods are discussed. In Chapter 2, a simulation study evaluates the performance of the length-converted catch curve (LCCC), Beverton-Holt equation (BHE), and Length Based-Spawner Potential Ratio (LB-SPR) over a range of scenarios. Although the LCCC and BHE are older methods than LB-SPR, the former outperformed LB-SPR in many scenarios in the simulation. Overall, it was found that the three length-based mortality estimators are less likely to perform well for low M/K stocks (M/K is the ratio of the natural mortality rate and the von Bertalanffy growth parameter; this ratio describes different life history strategies of exploited fish and invertebrate populations), while various decision rules for truncating the length data for the LCCC and BHE were less influential. In Chapter 3, a multi-stock model is developed for the non-equilibrium mean length-based mortality estimator and then applied to the deepwater snapper complex in Puerto Rico. The multispecies estimator evaluates synchrony in changes to the mean length of multiple species in a complex. Synchrony in mortality can reduce the number of estimated parameters and borrows information from more informative species to lesser sampled species in the model. In Chapter 4, a new method is developed to estimate mortality from both mean lengths and catch rates (MLCR), which is an extension of the mean length-only (ML) model. to do so, the corresponding behavior for the catch rate following step-wise changes in mortality is derived. Application of both models to Puerto Rico mutton snapper shows that the MLCR model can provide more information to support a more complex mortality history with the two data types compared to the ML model. In Chapter 5, a suite of mean length-based mortality estimators is applied to six stocks (four in the Gulf of Mexico and two in the U.S. Atlantic) recently assessed with age-structured models. There was general agreement in historical mortality trends between the age-structured models and the mean length-based methods, although there were some discrepancies which are discussed. All models also agreed on the overfishing status in the terminal year of the assessment of the six stocks considered here when the mortality rates were compared relative to reference points. This dissertation develops new length-based assessment methods which consider multiple sources of data. The review guides prospective users on potential choices for assessment with length-based methods. Issues and diagnostics associated with the methods are also discussed in the review and highlighted in the example applications.

Hurricanes are one of the deadliest and costliest natural hazards affecting the Gulf coast and Atlantic coast areas of the United States. An effective way to minimize hurricane damage is to strengthen structures and buildings. The investigation of surface level hurricane wind behavior and the resultant wind loads on structures is aimed at providing structural engineers with information on hurricane wind characteristics required for the design of safe structures. Information on mean wind profiles, gust factors, turbulence intensity, integral scale, and turbulence spectra and co-spectra is essential for developing realistic models of wind pressure and wind loads on structures. The research performed for this study was motivated by the fact that considerably fewer data and validated models are available for tropical than for extratropical storms. Using the surface wind measurements collected by the Florida Coastal Monitoring Program (FCMP) during hurricane passages over coastal areas, this study presents comparisons of surface roughness length estimates obtained by using several estimation methods, and estimates of the mean wind and turbulence structure of hurricane winds over coastal areas under neutral stratification conditions. In addition, a program has been developed and tested to systematically analyze Wall of Wind (WoW) data, that will make it possible to perform analyses of baseline characteristics of flow obtained in the WoW. This program can be used in future research to compare WoW data with FCMP data, as gust and turbulence generator systems and other flow management devices will be used to create WoW flows that match as closely as possible real hurricane wind conditions. Hurricanes are defined as tropical cyclones for which the maximum 1-minute sustained surface wind speeds exceed 74 mph. FCMP data include data for tropical cyclones with lower sustained speeds. However, for the winds analyzed in this study the speeds were sufficiently high to assure that neutral stratification prevailed. This assures that the characteristics of those winds are similar to those prevailing in hurricanes. For this reason in this study the terms tropical cyclones and hurricanes are used interchangeably.

A large amount of information concerning interatomic distances in the solid state is available, but little has been done in recent times to comprehensively filter, summarize and analyze this information. Here, I examine the distribution of bond lengths for 135 ions bonded to oxygen, using 180,331 bond lengths extracted from 9367 refined crystal structures collected from the Inorganic Crystal Structure Database (ICSD). The data are used to evaluate the parameterization of the bond-length—bond-valence relation of the bond-valence model. Published bond-valence parameters for 135 cations bonded to oxygen, and the various methods used in their derivation, are evaluated. New equations to model the relation are tested and the common form of the equation is found to be satisfactory. A new method (the Generalized Reduced Gradient Method, GRG method) is used to derive new bond-valence parameters for 135 cations bonded to oxygen, leading to significant improvements in fit for many of the ions. The improved parameterization is used to gain crystal-chemical insight into the milarite structure. A literature review of 350+ published compositions is done to review the end-members of the milarite group and to identify compositions that should have been described as distinct minerals species. The a priori bond-valences are calculated for minerals of this structure, and are used to examine the controls of bond topology on site occupancy, notably by localizing the major source of strain of the structure (the B site). Examination of the compositions of all known milarite-group minerals shows that compositions with a fully occupied B site are less common than those with a vacant B site, in accord with the idea that the B site is a local region of high strain in the structure. The bond-length distributions for the ions of the alkali and alkaline-earth metal families are examined. Variations in mean bond-lengths are only partly explained by the distortion theorem of the bond-valence model. I have found that bond length also correlates with the amount of vibrational displacement of the constituent ions. The validity of some uncommon coordination numbers, e.g., [3]-coordinated Li+, [3]-coordinated Be2+, is confirmed.
October 2016

Fracture systems or networks always control the stability, deformability, fluid and gas storage capacity and permeability, and other mechanical and hydraulic behavior of rock masses. The characterization of fracture systems is of great significance for understanding and analyzing the impact of fractures to rock mass behavior. Fracture trace data have long been used by engineers and geologists to character fracture system. For subsurface fractures, however, boreholes, wells, tunnels and other cylindrical samplings of fractures often provide high quality fracture trace data and have not been sufficiently utilized. The research work presented herein is intended to interpret fracture traces on borehole walls and other cylindrical surfaces by using stereology. The relationships between the three-dimension fracture intensity measure, P32, and the lower dimension fracture intensity measures are studied. The analytical results show that the conversion factor between the three-dimension fracture intensity measure and the two-dimension intensity measure on borehole surface is not dependent on fracture size, shape or circular cylinder radius, but is related to the orientation of the cylinder and the orientation distribution of fractures weight by area. The conversion factor between the two intensity measures is determined to be in the range of [1.0, π/2]. The conversion factors are also discussed when sampling in constant sized or unbounded fractures with orientation of Fisher distribution. At last, the author proposed estimators for mean fracture size (length and width) with borehole/shaft samplings in sedimentary rocks based on a probabilistic model. The estimators and the intensity conversion factors are tested and have got satisfactory results by Monte Carlo simulations.
Ph. D.

Fractures and fracture networks govern the mechanical and fluid flow behavior of rock masses. Tunneling and other rock mechanics applications therefore require the characterization of rock fractures based on geological data. Field investigations produce only a limited amount of data from boreholes, outcrops, cut slopes, and geophysical surveys. In tunneling, the process of excavation creates a priceless opportunity to gather more data during construction. Typically, however, these data are not utilized due to the impedance of sampling and analysis on the flow of construction, and safety concerns with sampling within unlined tunnel sections. However, the use of this additional data would increase the overall safety, quality, and cost savings of tunneling. This study deals with several aspects of the above, with the goal of creating methods and tools to allow engineers and geologists to gather and analysis fracture data in tunnels without interrupting the excavation and without compromising safety. Distribution-independent trace density and mean trace length estimators are developed using principles of stereology. An optimization technique is developed utilizing Differential Evolution to infer fracture size and shape from trace data obtained on two or more nonparallel sampling planes. A method of producing nearly bias free empirical trace length CDF's is also introduced. These new methods and tools were validated using Monte Carlo simulations. A field study was conducted in an existing tunnel allowing the above methods and tools to be further validated and tested. A relational database was developed to aid in storage, retrieval, and analysis of field data. Fracture models were built and updated using fracture data from within the tunnel. Utilization of state of the art imaging techniques allowed for remote sampling and analysis, which were enhanced by the use of 3d visualization techniques.
Ph. D.

碩士
朝陽科技大學
幼兒保育系碩士班
93
In this study, we set three experiments on detecting Mandarin-English bilingual children and monolingual children’s use of word-learning strategies and mean length of utterances. In these experiments, we use 4-year-old and 6-year-old Mandarin-English bilingual and Mandarin monolinguals children to discuss these experiments. In the first experiment, we focus on the mutual exclusivity constraint across children’s word-learning and compare the different performance between two groups of children. We found that both monolinguals and bilingual children would choose the referent objects correctly when different language inputs and 6-year-old children tendency stronger to use the mutual exclusivity constraint than 4-year-old children. In the second experiment, we add social context in a sentence to investigate whether influence inference of the word-meaning in monolinguals and bilingual or not. We found that both monolinguals and bilingual children would choose the referent objects correctly when they encountered stronger referential intention. These results show that Mandarin-English bilingual and Mandarin monolinguals children would adopt both the mutual exclusivity constraint and social-pragmatic cues to interpret the meanings of new words. In the final experiment, we show picture to children and to detecting children’s mean length of utterances. Results indicate that performance of speech productivity in 6-year-old children are better then 4-year-old and 4-year-old Mandarin-English bilingual children’s MLU are better than 4-year-old Mandarin children’s, but 6-year-old Mandarin children’s MLU are better than 6-year-old Mandarin-English bilingual children''s.

碩士
國立中正大學
語言學研究所
102
This study aims to make use of the mean length of utterances (MLU) to examine the ability of narrative of Taiwanese elderly adults. According to previous studies, firstly, older elderly adults’ MLU of narrative was shorter than younger, and which showed the tendency of different MLU produced by different age groups (Kynette & Kemper, 1986). Secondly, it showed the tendency that elderly adults with higher educational level produced longer MLU (Cheung & Kemper, 1992). And thirdly, the genre of narrative could affect significantly different MLU by elderly adults (Kemper, Kynette, Rash, O’Brien & Sprott, 1989). Thus, three major issues about this study are listed as the following. (1) Would age significantly affect elderly adults’ MLU? (2) Would educational level affect elderly adults’ MLU? (3) Would genre of narrative affect elderly adults’ MLU? The way of calculating MLU in Mandarin is based on words and syllables (Cheung, 1998). And the method of this study in Taiwanese Southern Min is to utilize MLU both by words (MLUw) and by syllables (MLUs) (Cheung, 1998), to examine the ability of 20 elderly adults, aged 65-85, from Minxiong Township in Chiayi County, in narrating their own experiences or stories and describing a story from wordless pictures in Taiwanese Southern Min. Besides the genre of narrative, the factors of age and education were manipulated, and the wordless picture book “Frog, where are you?” (Mayer, 1969) was used in the picture description. All the data were transcribed using the Adult-Corpus Romanization Input Program (Ruan, Hsu, Myers, & Tsay, 2012) of National Chung Cheng University, and IBM SPSS statistics V.21 was used to statistically analyze all the data, which amounted to 1,000 complete utterances from the narrative and 1,671 complete utterances from the picture description. The results showed (1) that age significantly affected MLUs in the narrative, and the older participants produced a significantly higher MLUs than the younger participants in the narrative; (2) that education level significantly affected MLUw and MLUs in the picture description, and the participants who had received six years of formal school education produced a significantly higher MLUs than the participants who were illiterate; and (3) that there was a significant difference between the MLUs of the narrative and the MLUs of the picture description, and the participants produced a significantly higher MLUs in the narrative than in the picture description. According to the results above, it can be inferred that elderly adults’ language performance may not undergo age-related decline. In some respects, the older participants’ language performance was even better than that of the younger participants. In addition, education level is perhaps a more significant factor in spontaneous picture descriptions than in narratives. The educated participants’ language performance in the picture description was better than that of the illiterate participant’s. However, education level may not predict a participant’s mean length of utterances in narratives.

The purpose of this analysis was to define norms for grammatical morpheme development in Spanish for Spanish-English bilingual children ages 4;0-7;6. This study uses secondary data analysis based on two existing datasets. Participants included 334 Spanish-English bilingual children that were recruited from school districts in Texas, Utah, and Pennsylvania. Grammatical morpheme accuracy was determined by performance on the BESA (Bilingual English Spanish Assessment) (Peña, Gutiérrez-Clellen et al., in preparation). Mean length of utterance in words (MLUw) data was collected from language samples. The average percent accuracy of grammatical morphemes was calculated and analyzed as a function of MLUw in Spanish. Results show that the percentage of accurately produced morphemes has a general upward trend as MLUw increases. Clinical and research implications are discussed.
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碩士
朝陽科技大學
幼兒保育系碩士班
94
This research was aimed to investigate the differences of mean utterance length and grammatical classes analysis between preschool children with Viefnames mothers and local native children. 63 research participants were selected from kindergartens within Taichung and Chunghua County. There children were divided into groups of four-year-old, five-year-old and six-year-old. By the approach of “read book and tell the story” these children were given a wordless picture book to read. The stories these children told were to be their language samples for carrying out measurement of language production: mean length of utterance and grammatical classes analysis. In mean length of utterance measuring with syllables (MLUs), children with Vietnamese mothers in four-year-old, five-year-old and six-year-old group were measured to be 5.00, 6.16 and 7.55, where children with native mothers in four-year-old, five-year-old and six-year-old groups were measured to be 7.00, 8.92 and 8.34. In mean length of utterance measuring with words (MLUw), children with Vietnamese mothers in four-year-old, five-year-old and six-year-old group were measured to be 3.00, 3.72 and 4.87, where children with native mothers in four-year-old, five-year-old and six-year-old group were measured to be 4.46, 5.21, and 4.94. The results of analysis indicated statistical native children was significant suspension to that children with Vietnamese mother and six-year-old group better then four-years-old group. In aspect of grammatical classes analysis, that children with Vietnamese mother were Noun and Verb statistical more then others, native children were Verb statistical more then others.

Typically developing Spanish-English bilingual children's production of twelve grammatical morphemes was analyzed for accuracy and described as a function of their English mastery, as indexed by mean length of utterance (MLU). Results revealed positive trends in morpheme accuracy as MLU increased. Despite a large degree of between subject variability, the data demonstrated general patterns that were consistent with previous literature, namely that the rate and trajectory of morpheme acquisition differs from monolingual norms, and that particular morphemes are predictably more and less challenging for bilingual children to produce accurately. MLU "cut-points" were suggested based on functional breaks in accuracy for several morphemes.
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O presente trabalho tem como objetivo principal analisar os vários subsistemas da linguagem oral em crianças com surdez pré-lingual, severa a profunda, utilizadoras de Implante Coclear (IC), dispositivo que possibilita a aquisição e o desenvolvimento da linguagem oral através da via auditiva. Dados sobre esta matéria em crianças a adquirir o Português Europeu são escassos e, muitas vezes, circunscritos, apenas, a certos aspetos da linguagem. Para além do estudo empírico feito com crianças surdas com IC e seus pares normoouvintes, procurámos enquadrar o trabalho fazendo uma revisão da literatura sobre: a) anatomia e fisiologia da audição, avaliação audiológica, tipos de surdez, próteses auditivas e implantes cocleares; b) aquisição e desenvolvimento dos vários subsistemas da linguagem oral e formas de avaliação; e c) aquisição e desenvolvimento da linguagem oral em crianças surdas utilizadoras de IC. Neste estudo foi analisada a linguagem oral de 19 crianças surdas com IC, entre os três e os nove anos de idade cronológica e os dois e os sete anos de idade auditiva (isto é, tempo decorrido desde a ativação do processador do IC), e de 38 crianças normo-ouvintes, emparelhadas por idade auditiva e por idade cronológica, constituindo, assim, dois grupos de comparação com 19 crianças cada. De forma a estudar-se os diferentes subsistemas da linguagem foi necessário utilizar vários instrumentos como medidas de linguagem: o Teste Fonético-Fonológico ALPE (TFF-ALPE), que avalia o desenvolvimento fonológico através da nomeação de imagens; o Teste de Avaliação da Linguagem na Criança (TALC), que avalia componentes de compreensão (semântica e morfossintaxe) e expressão (semântico, morfossintaxe e pragmática), e foi ainda analisada a linguagem espontânea através da Extensão Média do Enunciado em palavras (EME-p). Foi também avaliado o impacto da idade auditiva e do modo de comunicação preferencial (comunicação oral ou comunicação total) nos resultados linguísticos alcançados pelas crianças surdas utilizadoras de IC. No geral, verificou-se nas crianças surdas com IC uma tendência para a estabilização tardia do inventário consonântico e a presença de processos fonológicos, a nível da sílaba e do segmento, que tendem a persistir ao longo do tempo. Os resultados revelaram também que as crianças da amostra com mais tempo de uso de IC, particularmente a partir dos 5;0 anos de idade auditiva, apresentavam um inventário consonântico mais completo e um decréscimo no uso de processos fonológicos. Paralelamente, os resultados obtidos no desenvolvimento semântico e no desenvolvimento da pragmática (TALC) foram adequados à sua idade auditiva. Por outro lado, verificou-se um fraco desenvolvimento na morfossintaxe (TALC), e valores na EME-p substancialmente inferiores, mesmo considerando a idade auditiva. O modo de comunicação preferencial não teve impacto no desenvolvimento da linguagem oral. A EME-p correlacionou-se positiva e significativamente com o TALC (compreensão e expressão), mostrando que esta medida de linguagem espontânea é também um indicador válido do desenvolvimento da linguagem para esta população infantil. Podemos concluir que o desenvolvimento da linguagem oral de crianças surdas com IC não é uniforme entre os vários subsistemas de linguagem avaliados, verificando-se níveis de proficiência idênticos aos de crianças com desenvolvimento típico (considerando a idade auditiva) na semântica e na pragmática, mas acompanhados de um sistema fonológico imaturo e de um desenvolvimento morfossintático inferior ao dos seus pares normo-ouvintes emparelhados por idade auditiva. Em adição, a EME p, enquanto medida global do desenvolvimento da linguagem, também revelou valores substancialmente inferiores, mesmo tendo em conta o tempo de audição robusta (i.e., tempo de uso de IC) destas crianças.
The main goal of the present work is to analyze the several oral language subsystems in children with prelingual severe-to-profound hearing loss who use cochlear implant (CI). The CI is a device that enables the acquisition and development of language through the auditory pathway. Data regarding children with CI, acquiring European Portuguese is limited and several times restricted to certain language matters. On top of the empiric study performed to deaf children with CI and their respective normally-hearing peers, we envisaged introducing the work by showing a literature revision regarding: a) anatomy and physiology of hearing, audiology evaluation, types of deafness, hearing aids and cochlear implants; b) acquisition and development of the several oral language subsystems and respective forms of assessment; and c) acquisition and development of oral language in deaf children with CI. In this study, we analyzed the language of 19 deaf children with CI with three to nine years of chronological age and two to seven years of hearing age (meaning the time elapsed since the activation of the CI processor). Additionally, we constitute two comparison groups, with 19 normal hearing children each (with a total of 38) paired by hearing age and chronological age, with the group of deaf children with cochlear implants. Moreover, we implement several instruments as language measures, to study the different language subsystems, namely: Teste Fonético-Fonológico ALPE (TFFALPE), that assesses phonological development through the naming of pictures; Teste de Avaliação da Linguagem na Criança (TALC), which encompass receptive language (semantics and morphosyntax) and expressive language (semantics, morphosyntax and pragmatics). Furthermore, it was also analyzed spontaneous speech samples through Mean Length of Utterance in words (MLU-w) and also, the impact of the hearing age and preferred communication mode (oral communication or total communication) on the linguistic results achieved by deaf children CI users. In general, deaf children with CI exhibit a tendency towards a late stabilization of the consonant inventory and the presence of phonologic processes, at the syllable and segment level, tend to persist over time. The results also revealed that the children in the sample with more extended use of CI, particularly from 5 years of hearing age on, had a more extensive consonant inventory and a decrease in the use of phonological processes when compared to deaf children with less time of implant experience. Moreover, the obtained results in the semantics and pragmatics (TALC) were adequate to their hearing age. On the other hand, there was a weak development in the morphosyntax (TALC), and the values in the EME-p were substantially lower, even considering the hearing age. The preferred communication method did not affect the development of oral language. The EME-p was positively and significantly correlated with TALC (comprehension and expression), illustrating that the measurement of spontaneous language through this index is also a valid indicator of language development in this population. In conclusion, language development in deaf children with CI was not uniform regarding the several language subsystems assessed. Moreover, we identify proficiency levels in deaf children with cochlear implants similar to their normal hearing peers (considering their hearing age) in the semantics and pragmatics; on the other hand, an immature phonological system and a morphosyntactic weak development were also attested in the group of deaf children, based on their hearing age. In addition, the EME-p, a global measure of language development, also revealed substantially lower values, even taking into account the length of children's robust auditory experience (i.e. hearing age).

Diversos estudos têm demonstrado que o nascimento pré-termo pode levar a alterações no desenvolvimento neurológico e a consequentes compromissos, nomeadamente do processamento e desenvolvimento linguístico. O presente estudo visa investigar se as crianças de nascimento muito prematuro a prematuro ligeiro (28 a 36 semanas) apresentam valores de Extensão Média do Enunciado em palavras (EME-p) mais baixos do que os considerados de referência aos 4 e 5 anos. Pretende-se também verificar no grupo de crianças prematuras se o número de semanas gestacionais e o peso à nascença influenciam os valores da EME-p e se existem diferenças condicionadas pelo género. Participaram no estudo 19 crianças prematuras (9 rapazes e 10 raparigas) matriculadas em jardins-de-infância da área da Grande Lisboa. O discurso destas crianças foi gravado durante 30 minutos e posteriormente transcrito para o software ELAN 4.1.2 para ser devidamente analisado. Verificou-se que os valores da EME-p de crianças prematuras são inferiores aos valores de referência aos 4 e 5 anos. Tanto o tempo de gestação como o peso à nascença se correlacionam de forma positiva e significativa com a EME-p. Não foram verificadas diferenças condicionadas pelo género nem pela escolaridade dos pais.
Several studies have shown that preterm birth can lead to abnormal neurological development that often leads to a compromise of processing and language development. Some studies also show that factors such as birth weight, parents' education and gender can significantly influence the language development of preterm infants. This work aims to verify whether children from very preterm birth to late preterm birth (28-36 weeks) present values of Mean Length of Utterance in words (MLU-w) lower than those considered in reference to the 4 and 5 years. We also intend to verify the group of premature children is the number of gestational weeks and birth weight influence the values of MLU-w and if there are differences conditioned by gender. Participated in this study 19 premature infants (9 boys and 10 girls) enrolled in kindergartens of the Greater Lisbon area. The speech of these children was recorded for 30 minutes and subsequently transcribed for ELAN 4.1.2 software to be properly analyzed. It was found that the values of MLU-w of preterm infants are lower than the reference values at 4 and 5 years. Both gestational age as birth weight correlated positively and significantly with the MLU-w. No differences conditioned by gender or by parental education were found.

A exposição de crianças à leitura de histórias infantis contribui para o desenvolvimento das suas habilidades narrativas, constituindo um importante indicador do desempenho escolar das mesmas (Verzolla, Isotani & Perissinoto, 2012). Existem também estudos que referem evoluções nas competências de atenção, escuta, sequencialização, vocabulário, organização de ideias e leitura e escrita (Reed, 1987; Speaker, Taylor & Kamen, 2004). A presente investigação, de caráter longitudinal, teve como objetivo principal analisar o contributo que um programa de leitura de histórias em contexto de grupo pode ter no desempenho linguístico de crianças entre os 4 e os 5 anos de idade, nomeadamente nos valores de Percentagem de Consoantes Corretas, Comprimento Médio de Enunciado, Memória Auditiva, assim como inteligibilidade da fala encadeada. O estudo foi realizado no Hospital-Escola da Universidade Fernando Pessoa, após parecer positivo da Comissão de Ética desta mesma instituição. A amostra foi constituída por 14 crianças com perturbação de linguagem primária, com idades compreendidas entre os 4 e os 5 anos, distribuídos por dois grupos de estudo, um experimental e um de controlo. O grupo experimental usufruiu de intervenção de um programa de leitura de contos infantis, juntamente com sessões individuais de terapia da fala. O grupo controlo recebeu sessões de terapia da fala individual. As crianças foram avaliadas relativamente às medidas: Percentagem de Consoantes Corretas, Comprimento Médio de Enunciado, Memória Auditiva e Inteligibilidade. Os resultados sugerem melhorias da Percentagem de Consoantes Corretas e do Comprimento Médio de Enunciado, contudo não se verificou efeito da eficácia de intervenção nestas medidas. Na memória auditiva os resultados parecem indicar um efeito de intervenção significativo nas tarefas de palavras e ordens. Relativamente à avaliação de inteligibilidade, constatou-se concordância elevada entre avaliadores, contudo os resultados no grupo experimental (antes e após avaliação) mostraram-se discutíveis. A opinião dos pais em relação à intervenção em contexto de grupo foi avaliada como favorável/muito favorável.
The children's exposure to reading stories contributes to the development of their narrative abilities, constituting an important indicator of their educational performance (Verzolla, Isotani & Perissinoto, 2012). There are also studies that show evolutions in attention, listening, sequencing, vocabulary, organization of ideas, reading and writing skills (Reed, 1987; Speaker, Taylor & Kamen, 2004). This study analyze the contribution of a group reading program can in the linguistic performance of children between 4 and 5 years old, measured by Percentage of Consonants Correct, Mean Length Utterance, Auditory Memory, and speech intelligibility. The study was carried out at Hospital-Escola Universidade Fernando Pessoa, after a positive opinion from the Ethics Committee of this institution. The sample consisted of 14 children with primary language disorder, aged between 4 and 5 years, divided into two study groups, one experimental and one control group. The experimental group benefited from an intervention program of children's storytelling, along with individual speech therapy sessions. The control group received individual speech therapy sessions. The children were evaluated for the measures: Percentage of Percentage of Consonants Correct, Mean Length Utterance, Auditory Memory, and speech intelligibility. The results suggest improvements in the percentage of correct consonants and the Mean Length Utterance, but there was no effect of intervention effectiveness on these measures. In auditory memory the results seem to indicate a significant intervention effect on words and order’s tasks. Regarding the intelligibility evaluation, there was a high agreement between evaluators, but the results in the experimental group (before and after evaluation) were questionable. The parents' opinion regarding the intervention in a group context was evaluated as favorable / very favorable.

Desired base upper half mean length (UHML) of upland cotton (G. hirsutum) in the U.S. has been set a 27.0 mm and is shorter than the standard set by the international community. Upland cotton genotypes from China, South Africa, West Africa, and the U.S. were test crossed to an extra long staple upland (ELSU) and a short staple upland (SSU) and selected genotypes that included both ELSU and MSU phenotypes were crossed in a half-diallel mating scheme to estimate general combing ability (GCA) effects and specific combining ability (SCA) effects. A recombinant inbred line (RIL) population was established to determine the narrow sense heritability (h^2) of AFIS short fiber content by weight (SFCw) and lower half mean length (LHML) and to estimate SFCw using HVI fiber properties. Obsolete cultivars from China are not likely sources for UHML improvement, cultivars from Africa and the U.S. could harbor alleles not being used in current elite short staple cultivars or modern ELSU cultivars. Two ELSU lines used in this study derived through interspecific hybridization with G. barbadense could contain alleles for UHML improvement in modern ELSU cultivars developed without any apparent G. barbadense introgression. A third line D&PL 45-867, might contain alleles for UHML improvement in long staple upland cotton genotypes. Narrow sense heritability estimates indicated a much higher heritability of LHML than AFIS SFCw. Correlation between AFIS SFCw and LHML did not agree with previous studies when using an ELSU X MSU cross. Further study is needed to understand this complex relationship.

This thesis theoretically investigates the electronic transport properties of defective carbon nanotubes (CNTs). For the defects the focus is set to vacancy types. The calculations are performed using quantum transport theory and an underlying density-functional-based tight-binding method. Two algorithmic improvements are derived, which accelerate the common methods for quasi one-dimensional systems for the specific case of (i) randomly distributed defects and (ii) long unit cells. With this, the transmission spectrum and the conductance is calculated as a function of the CNT length, diameter, chiral angle, defect type, defect density, defect fraction, and temperature. The diffusive and the localized transport regime are described by extracting elastic mean free paths and localization lengths for metallic and semiconducting CNTs. Simple analytic models for estimating or even predicting the conductance dependence on the mentioned parameters are derived. Finally, the formation of defect-induced long-range deformations and its influence on the conductance are studied.:1 Introduction 2 Fundamentals 2.1 Carbon nanotubes 2.1.1 Structure 2.1.2 Properties 2.1.3 Defects 2.1.4 Synthesis 2.1.5 Characterization 2.1.6 Applications 2.2 Electron structure theory 2.2.1 Introduction 2.2.2 Density functional theory 2.2.3 Density-functional-based tight binding 2.2.3.1 First-order expansion 2.2.3.2 Creation of the parameter set 2.2.3.3 Second-order expansion 2.2.3.4 Usage 2.3 Electron transport 2.3.1 Equilibrium Green’s-function-based quantum transport theory 2.3.2 Transport regimes 2.3.3 Classical derivation: drift-diffusion equation with a sink 2.3.4 Quantum derivation: Dorokhov-Mello-Pereyra-Kumar theory A Improved recursive Green’s function formalism for quasi one-dimensional systems with realistic defects (J. Comput. Phys. 334 (2017), 607–619) A.1 Introduction A.2 Quantum transport theory A.3 Recursive Green’s function formalisms A.3.1 Forward iteration scheme A.3.2 Recursive decimation scheme A.3.3 Renormalization decimation algorithm A.4 Improved RGF+RDA A.5 Performance test A.5.1 Random test matrix A.5.2 Transport through carbon nanotubes A.6 Summary and conclusions B Strong localization in defective carbon nanotubes: a recursive Green’s function study (New J. Phys. 16 (2014), 123026) B.1 Introduction B.2 Theoretical framework B.2.1 Transport formalism B.2.2 Recursive Green’s function formalism B.2.3 Electronic structure B.2.4 Strong localization B.3 Modeling details of the defective system B.4 Results and discussion B.4.1 Single defects B.4.2 Randomly distributed defects B.4.3 Localization exponent B.4.4 Diameter dependence and temperature dependence of the localization exponent B.5 Summary and conclusions Supplementary material C Electronic transport in metallic carbon nanotubes with mixed defects within the strong localization regime (Comput. Mater. Sci. 138 (2017), 49–57) C.1 Introduction C.2 Theoretical framework C.3 Modeling details C.4 Results and discussion C.4.1 Conductance C.4.2 Localization exponent C.4.3 Influence of temperature C.4.4 Conductance estimation C.5 Summary and conclusions D An improved Green’s function algorithm applied to quantum transport in carbon nanotubes (arXiv: 1806.02039) D.1 Introduction D.2 Electronic transport D.3 Decimation technique and renormalization-decimation algorithm D.4 Renormalization-decimation algorithm for electrodes with long unit cells D.4.1 Surface Green’s functions D.4.2 Bulk Green’s functions and electrode density of states D.5 Complexity measure and performance test D.6 Exemplary results D.7 Summary and conclusions E Electronic transport through defective semiconducting carbon nanotubes (J. Phys. Commun. 2 (2018), 105012) E.1 Introduction E.2 Theoretical framework E.3 Modeling details E.4 Results and discussion E.4.1 Transmission and transport regimes E.4.2 Energy dependent localization exponent and elastic mean free path E.4.3 Conductance, effective localization exponent and effective elastic mean free path E.5 Summary and conclusions Supplementary material F Influence of defect-induced deformations on electron transport in carbon nanotubes (J. Phys. Commun. 2 (2018), 115023) F.1 Introduction F.2 Theory F.3 Results F.4 Summary and conclusions 3 Ongoing work 4 Summary and outlook 4.1 Summary 4.2 Outlook 5 Appendix 5.1 Bandstructure of graphene 5.2 Quantum transport theory and Landauer-Büttiker formula References List of figures List of tables Acknowledgement Selbstständigkeitserklärung Curriculum vitae List of publications
Diese Dissertation untersucht mittels theoretischer Methoden die elektronischen Transporteigenschaften von defektbehafteten Kohlenstoffnanoröhren (englisch: carbon nanotubes, CNTs). Dabei werden Vakanzen als Defekte fokussiert behandelt. Die Berechnungen werden mittels Quantentransporttheorie und einer zugrunde liegenden dichtefunktionalbasierten Tight-Binding-Methode durchgeführt. Zwei algorithmische Verbesserungen werden hergeleitet, welche die üblichen Methoden für quasi-eindimensionale Systeme für zwei spezifische Fälle beschleunigen: (i) zufällig verteilte Defekte und (ii) lange Einheitszellen. Damit werden das Transmissionsspektrum und der Leitwert als Funktion von CNT-Länge, Durchmesser, chiralem Winkel, Defekttyp, Defektdichte, Defektanteil und Temperatur berechnet. Das Diffusions- und das Lokalisierungstransportregime werden beschrieben, indem die elastische freie Weglänge und die Lokalisierungslänge für metallische und halbleitende CNTs extrahiert werden. Einfache analytische Modelle zur Abschätzung bis hin zur Vorhersage des Leitwertes in Abhängigkeit besagter Parameter werden abgeleitet. Schlussendlich werden die Bildung einer defektinduzierten, langreichweitigen Deformation und deren Einfluss auf den Leitwert studiert.:1 Introduction 2 Fundamentals 2.1 Carbon nanotubes 2.1.1 Structure 2.1.2 Properties 2.1.3 Defects 2.1.4 Synthesis 2.1.5 Characterization 2.1.6 Applications 2.2 Electron structure theory 2.2.1 Introduction 2.2.2 Density functional theory 2.2.3 Density-functional-based tight binding 2.2.3.1 First-order expansion 2.2.3.2 Creation of the parameter set 2.2.3.3 Second-order expansion 2.2.3.4 Usage 2.3 Electron transport 2.3.1 Equilibrium Green’s-function-based quantum transport theory 2.3.2 Transport regimes 2.3.3 Classical derivation: drift-diffusion equation with a sink 2.3.4 Quantum derivation: Dorokhov-Mello-Pereyra-Kumar theory A Improved recursive Green’s function formalism for quasi one-dimensional systems with realistic defects (J. Comput. Phys. 334 (2017), 607–619) A.1 Introduction A.2 Quantum transport theory A.3 Recursive Green’s function formalisms A.3.1 Forward iteration scheme A.3.2 Recursive decimation scheme A.3.3 Renormalization decimation algorithm A.4 Improved RGF+RDA A.5 Performance test A.5.1 Random test matrix A.5.2 Transport through carbon nanotubes A.6 Summary and conclusions B Strong localization in defective carbon nanotubes: a recursive Green’s function study (New J. Phys. 16 (2014), 123026) B.1 Introduction B.2 Theoretical framework B.2.1 Transport formalism B.2.2 Recursive Green’s function formalism B.2.3 Electronic structure B.2.4 Strong localization B.3 Modeling details of the defective system B.4 Results and discussion B.4.1 Single defects B.4.2 Randomly distributed defects B.4.3 Localization exponent B.4.4 Diameter dependence and temperature dependence of the localization exponent B.5 Summary and conclusions Supplementary material C Electronic transport in metallic carbon nanotubes with mixed defects within the strong localization regime (Comput. Mater. Sci. 138 (2017), 49–57) C.1 Introduction C.2 Theoretical framework C.3 Modeling details C.4 Results and discussion C.4.1 Conductance C.4.2 Localization exponent C.4.3 Influence of temperature C.4.4 Conductance estimation C.5 Summary and conclusions D An improved Green’s function algorithm applied to quantum transport in carbon nanotubes (arXiv: 1806.02039) D.1 Introduction D.2 Electronic transport D.3 Decimation technique and renormalization-decimation algorithm D.4 Renormalization-decimation algorithm for electrodes with long unit cells D.4.1 Surface Green’s functions D.4.2 Bulk Green’s functions and electrode density of states D.5 Complexity measure and performance test D.6 Exemplary results D.7 Summary and conclusions E Electronic transport through defective semiconducting carbon nanotubes (J. Phys. Commun. 2 (2018), 105012) E.1 Introduction E.2 Theoretical framework E.3 Modeling details E.4 Results and discussion E.4.1 Transmission and transport regimes E.4.2 Energy dependent localization exponent and elastic mean free path E.4.3 Conductance, effective localization exponent and effective elastic mean free path E.5 Summary and conclusions Supplementary material F Influence of defect-induced deformations on electron transport in carbon nanotubes (J. Phys. Commun. 2 (2018), 115023) F.1 Introduction F.2 Theory F.3 Results F.4 Summary and conclusions 3 Ongoing work 4 Summary and outlook 4.1 Summary 4.2 Outlook 5 Appendix 5.1 Bandstructure of graphene 5.2 Quantum transport theory and Landauer-Büttiker formula References List of figures List of tables Acknowledgement Selbstständigkeitserklärung Curriculum vitae List of publications

abstract: In modern electric power systems, energy management systems (EMSs) are responsi-ble for monitoring and controlling the generation system and transmission networks. State estimation (SE) is a critical `must run successful' component within the EMS software. This is dictated by the high reliability requirements and need to represent the closest real time model for market operations and other critical analysis functions in the EMS. Tradi-tionally, SE is run with data obtained only from supervisory control and data acquisition (SCADA) devices and systems. However, more emphasis on improving the performance of SE drives the inclusion of phasor measurement units (PMUs) into SE input data. PMU measurements are claimed to be more accurate than conventional measurements and PMUs `time stamp' measurements accurately. These widely distributed devices meas-ure the voltage phasors directly. That is, phase information for measured voltages and currents are available. PMUs provide data time stamps to synchronize measurements. Con-sidering the relatively small number of PMUs installed in contemporary power systems in North America, performing SE with only phasor measurements is not feasible. Thus a hy-brid SE, including both SCADA and PMU measurements, is the reality for contemporary power system SE. The hybrid approach is the focus of a number of research papers. There are many practical challenges in incorporating PMUs into SE input data. The higher reporting rates of PMUs as compared with SCADA measurements is one of the salient problems. The disparity of reporting rates raises a question whether buffering the phasor measurements helps to give better estimates of the states. The research presented in this thesis addresses the design of data buffers for PMU data as used in SE applications in electric power systems. The system theoretic analysis is illustrated using an operating electric power system in the southwest part of the USA. Var-ious instances of state estimation data have been used for analysis purposes. The details of the research, results obtained and conclusions drawn are presented in this document.
Dissertation/Thesis
M.S. Electrical Engineering 2013

Splitter plates are passive flow control devices for reducing drag and suppressing vortex shedding from bluff bodies. Most studies of splitter plates involve the flow around an “infinite” circular cylinder, however, in the present study the flow around a surface-mounted finite-height circular cylinder, with a wake-mounted splitter plate, was studied experimentally in a low-speed wind tunnel using a force balance and single-component hot-wire anemometry. Four circular cylinders of aspect ratios AR = 9, 7, 5 and 3 were tested for a Reynolds number range of Re = 1.9×10^4 to 8.2×10^4. The splitter plates had lengths, relative to the cylinder diameter, of L/D = 1, 1.5, 2, 3, 5 and 7, thicknesses ranging from T/D = 0.10 and 0.15, and were the same height as the cylinder being tested. The cylinders were partially immersed in a flat-plate turbulent boundary layer, where the range of boundary layer thickness relative to the cylinder diameter was δ/D = 1.4 to 1.5. Measurements were made of the mean drag force coefficient, the Strouhal number at the mid-height position, and the Strouhal number and power spectra along the cylinder height. For all four finite circular cylinders, the splitter plates were effective at reducing the magnitude of the Strouhal number, and weakening or even suppressing vortex shedding, depending on the specific combination of AR and L/D. Compared to the case of an infinite circular cylinder, the splitter plate is less effective at reducing the mean drag force coefficient of a finite circular cylinder. The largest drag reduction was obtained for the cylinder of AR = 9 and splitter plates of L/D = 1 to 3, while negligible drag reduction occurred for the shorter cylinders.

Being able to extrapolate interaction values from a database of pullout resistance testing results may possibly help with narrowing down the most suitable reinforcement/fill material combinations for a Mechanically Stabilized Earth wall, thereby reducing the number of tests needed for a design and maximizing the efficiency of the system. The objectives of this thesis include the following: collect and organize a broad collection of data in a way that can assist in preliminary selection of interaction properties for uniaxial geogrids; analyze the collection of data for trends related to geogrid polymer type; analyze the collection of data for trends related to the presence of fines in the fill material; compare the collected data to previous studies on the effects of geogrid specimen length on pullout performance; and compare the collected data to previous studies on the effect of geogrid rib thickness to mean particle size ratio on normalized bearing stress and CI values. The data from 101 pullout tests are presented in tabular and graphic form so that the coefficient of interaction may be interpolated for many geogrid/fill material combinations. The effect of polymer type (PET vs HDPE) was shown to have little effect on how a geogrid performs in a fill material. In one case, the two polymer types exhibit differing trends within the same fill material. The presence of fines (>12% by weight) in the fill material results in a significant decrease in the coefficient of interaction when compared to clean granular fills. The effects of geogrid embedment length have significant effects on the results of geogrid pullout tests. Samples with shorter lengths were shown to carry a greater load per unit area than longer samples. Normalized bearing stress is shown to be heavily influenced by the geogrid transverse rib thickness to mean particle size ratio (B/D50). For a particular fill material, normalized bearing stress decreases linearly with increasing B/D50. For a particular geogrid, normalized bearing stress is shown to have a bi-linear behavior with increasing B/D50. Initially, normalized bearing stress increases with increasing B/D50. After reaching a peak, normalized bearing stress begins to decrease with increasing B/D50.
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Plasmonic properties and the related novel applications are studied on various types of metallic nano-structures in one, two, or three dimensions. For 1D nanostructure, the motion of free electrons in a metal-film with nanoscale thickness is confined in its normal dimension and free in the other two. Describing the free-electron motion at metal-dielectric surfaces, surface plasmon polariton (SPP) is an elementary excitation of such motions and is well known. When further perforated with periodic array of holes, periodicity will introduce degeneracy, incur energy-level splitting, and facilitate the coupling between free-space photon and SPP. We applied this concept to achieve a plasmonic perfect absorber. The experimentally observed reflection dip splitting is qualitatively explained by a perturbation theory based on the above concept. If confined in 2D, the nanostructures become nanowires that intrigue a broad range of research interests. We performed various studies on the resonance and propagation of metal nanowires with different materials, cross-sectional shapes and form factors, in passive or active medium, in support of corresponding experimental works. Finite- Difference Time-Domain (FDTD) simulations show that simulated results agrees well with experiments and makes fundamental mode analysis possible. Confined in 3D, the electron motions in a single metal nanoparticle (NP) leads to localized surface plasmon resonance (LSPR) that enables another novel and important application: plasmon-heating. By exciting the LSPR of a gold particle embedded in liquid, the excited plasmon will decay into heat in the particle and will heat up the surrounding liquid eventually. With sufficient exciting optical intensity, the heat transfer from NP to liquid will undergo an explosive process and make a vapor envelop: nanobubble. We characterized the size, pressure and temperature of the nanobubble by a simple model relying on Mie calculations and continuous medium assumption. A novel effective medium method is also developed to replace the role of Mie calculations. The characterized temperature is in excellent agreement with that by Raman scattering. If fabricated in an ordered cluster, NPs exhibit double-resonance features and the double Fano-resonant structure is demonstrated to most enhance the four-wave mixing efficiency.