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Al-Murani, Thabit. "The Deliberate Use of Variation to Teach Algebra: A Realistic Variation Study." Thesis, University of Oxford, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.486965.
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This thesis investigates the effect(s) that deliberate and systematic use of dimensions of variation (DoV) in the teaching of mathematics can have for the students' learning. Variation theory, together with its practical application as an educational approach, is introduced (Marton and Booth, 1997). A realistic quasi-experimental longitudinal intervention called the Dimensions of Variation Programme, DVP, was designed and implemented to examine how this approach can potentially influence the understanding of students in algebra classrooms. The design was realistic because careful consideration was given to how the realities of the educational environment 'could be appropriately incorporated into the intervention in order to increase pragmatic validity. Convenience sampling was used to obtain a cohort of approximately 300 students. This sample corresponded to ten intact classes drawn from eight Oxfordshire schools. Six of the classes were taught by intervention teachers with the remaining four classes being taught by comparison teachers. The students were followed over a 14 month period between Year 7 and Year 8. The intervention teachers formed a research community which met regularly to discuss and jointly plan how the algebra content could be handled with awareness to dimensions of variation. o Classes were observed for eight lessons in total during the 14 months, four consecutive algebra lessons at the beginning of the intervention and four consecutive lessons toward .the end of the intervention. During these observations the mathematical dimensions of variation, together with some contextual details, were recorded. This formed the predictive data for the study. The students were pre-, post-, and delayed post-tested using national SAT exams. Scores from these were used as the primary outcome measure. These data were subsequently analysed both qualitatively and quantitatively in order to identify any differences that might exist between the intervention and comparison groups. The findings suggest that the intervention teachers handled the content in qualitatively different ways to the comparison teachers. The principle distinguishing characteristic between groups was that the intervention teachers exhibited an awareness for 'systematicity of inference' while the comparison teachers did not. There is some evidence to suggest that the intervention significantly affected students' learning outcomes in algebra between Year 7 and Year 8.
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Klein, Yolandi. "Syntactic variation in Afrikaans : an empirical study." Master's thesis, University of Cape Town, 2009. http://hdl.handle.net/11427/3604.
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Includes bibliographical references (leaves 114-122).This dissertation presents a variationist analysis of syntactic variation and change in modern spoken Afrikaans. The Afrikaans language community is heterogeneous, and can be divided into different communication communities according to patterns of segregated residential settlement and limited social interaction (linked to South Africa's history of apartheid). The selection of a sample for the study is informed by these realities and the sample is kept deliberately homogenous (following Barbiers, Cornips and Van der Kleij, 2000): participants (N=34) are White middle-class speakers of Afrikaans who are under 36 years of age and have been residing in Cape Town for at least the past seven to ten years. In addition, all participants are bilingual in English (as established through an electronically administered language use survey).In order to combine formal theory (generative linguistics) withΓÇó empirical analysis (sociolinguistics), the methodology follows a bi-modal approach. Both performance and competence are considered, and arguments are based on two types of data: speech data (interviews, narrative picture descriptions) and grammaticality judgements (elicited by means of an oral questionnaire). Grosjean's (2001) language mode model assists in refining the methodology of the study, because it recognises the fact that a bilingual speaker is a unique speaker-hearer (Chomsky, 1965). The empirical data are elicited in near-monolingual Afrikaans language modes. The results are quantified according to token frequencies and analyzed in comparison to other studies; significance tests are carried out using Chi-square and Fisher's exact tests. From the literature, the consensus seems to be that the word order in Afrikaans (XV structure) is changing to resemble an English frame (VX structure) because of language contact (cf, inter alia, Conradie, 2004; Donaldson, 1991). Two syntactic variables are studied to investigate variation in word order and verb placement: firstly, changes from XV to VX in subordinate clauses are explored by looking at the use of specific types of subordinate clauses, and the impact of matrix clause bridge verbs on complementizer omission and dependent/independent word order in the speech corpora. Secondly, the study examines the use of direct linking verbs and the role that complex verb initials play in proliferating VX structures. The findings are as follows: with embedded clause word order, the corpus data provides evidence of the frequent use of complementizer-less VX subordinate clauses that were not formally elicited in the questionnaire. These clauses have an important impact on variation in Afrikaans word order, leading to the proliferation of VX embedded clauses. Contributing factors are the weakening of the complementizer's semantic strength, and the role of the bridge verb as quotative marker in the matrix clause. Furthermore, the corpus data shows high frequencies of non-standard complementizer-led VX clauses, especially when compared to their low meta-linguistic acceptance in the questionnaires. The data thus shows significant variation in embedded clause word order and suggests that we are witnessing a change in progress for this variable. With respect to complex verb initials, the study finds a high acceptance rate in the questionnaires, as well as regular use in the spoken language corpus. By comparing the use of complex verb initials to a previous study (Ponelis, 1993) the study establishes a change in real time where an increase in the use of complex verb initials promotes the suspension of the main verb in clause-final position (V-final). The study recommends that that the bi-modal approach of considering both performance and competence data should be applied to similar studies of other groups in the Afrikaans language community.
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Guo, Kunde. "Plasma lipoprotein metabolism and genetic variation of fatness in broilers." Thesis, University of Edinburgh, 1988. http://hdl.handle.net/1842/13966.
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Khan, Farhat. "Linguistic variation in Indian English : a sociolinguistic study." Thesis, University of Reading, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328649.
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The present study responds to the longstanding need within the field of applied sociolinguistics for a better understanding of L2 variability. The study is concerned with the nature of phonological variation in the use of English by Indians. It is an attempt to use sociolinguistic methodology In examInIng a second language situation and to investigate: 1. Whether L2 variability is conditioned by linguistic constraints, and 2. Whether there is any social significance associated with L2 variability. The study is based on the data collected from 44 educated speakers of English in Aligarh (North India). The data was analysed by means of a variety of statistical and computer based programmes. Forty five minutes long interview was conducted by means of a questionnaire. The tasks, ranging from the informal to the most formal, were: (i) casual speech, (ii) short responses or interview style, (iii) reading passage and sentences, and (iv) reading minimal paIrs. There was, of course, no way to eliminate completely the influence of the interview situation, which generally causes speech to be more formal than casual. However, a number of techniques were used to enable the informants to relax and speak more casually. The first chapter deals with the socio-cultural and historical aspect of English in India. The second chapter looks at various theoretical approaches to the study of linguistic variability. The third chapter discusses the research methodology adopted for the present study. The fourth chapter examines the linguistic variants in different phonolog'ical environments and confirms our hypothesis that linguistic variation in second language IS systematic at the level of both the individual and the group. In the fifth chapter phonological variables have been analysed in relation to social demographic variables, such as schooling, education, age, sex and social class. The analysis in the sixth chapter deals with stylistic variation and shows a wide variation in different styles of speech. The seventh chapter very briefly examines intelligibility of Indian English and suggests that a change is probably taking place in Indian English due to social and political pressures within the country, particularly affecting younger generation. The last chapter begins with a brief discussion of the major findings and their social and linguistic implications and suggests ways in which the insights gained from the study can be utilised in the teaching of English as a second language.
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Al-Tahir, H. A. M. "Linguistic variation in Khartoum Arabic : A sociolinguistic study." Thesis, University of Reading, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374867.
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This thesis 1S a data-oriented sociolinguistic study of linguistic variation 1n the spoken variety of the Arabic-speaking speech community of Khartoum (capital of the Sudan). It sets out to investigate some salient phonological and morphological variables and their correlation with some social parameters. The reciprocal influences of the Classical and the Colloquial Arabic varieties are measured quantitatively in the data elicited through structured interviews from specific social groups whose members were randomly selected. Relation of norms of appropriateness' to actual linguistic behaviour is also investigated. Chapter One provides a brief account on the general characteristics of the linguistic situation in the country, a short review of the previous dialectological studies, the range and social evaluation of the major varieties of Arabic and a discussion of the theoretical problems involved in the distinction of context-specific varieties in Arabic. Chapter Two gives a brief survey of the major approaches to the study of linguistic variation and describes the theoretical framework of the study. Chapter Three discusses the methodological questions pertaining to data collection in the relevant area and describes the method followed in the study. Chapter Four presents the phonological variables and discusses their variants. Chapter Five deals with results and analysis of each phonological variable for each social group. Explanations are attempted as to the different patterning of variables in the linguistic behaviour of the different social groups. A small unquantified data on the 'feminine variety' is presented with reference to the lexical and supra-segmental features. Chapter Six discusses two grammatical features: the future tense marker and the demonstrative. Results and analysis of the study are presented with discussion. Chapter Seven provides a summary of the major types of variation in Sudanese Arabic with discussion of the main findings of the study and some of their methological and theoretical implications. These are then followed by appendices presenting questionnaires relevant to the study.
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Bourgerie, Dana Scott. "A quantitative study of sociolinguistic variation in Cantonese." The Ohio State University, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=osu1272299172.
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Bourgerie, Dana Scott. "A quantitative study of sociolinguistic variation in Cantonese /." The Ohio State University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487684245465545.
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Stopford, Cheryl Lee. "Phenotypic variation in Alzheimer's disease : A neuropsychological study." Thesis, University of Manchester, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.517369.
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Teacher, Amber. "Population and Immunocompetent Genetic Variation : A Field-Based Study." Thesis, Queen Mary, University of London, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.522329.
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Gettings, Karen Mercedes González-Valentín. "Study of CMOS process variation by multiplexing analog characteristics." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40499.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.Includes bibliographical references (p. 149-152).
Aggressive technology scaling raises the need for efficient methods to characterize and model circuit variation at both the front and back end of line, where critical parameters such as threshold voltage and parasitic capacitance must be carefully modeled for accurate circuit performance. This thesis addresses this need by contributing a test circuit methodology for the extraction of spatial, layout and size dependent variations at both device and interconnect levels. The test chip uses a scan chain approach combined with low-leakage and low-variation switches, and Kelvin sensing connections, providing access to detailed analog device characteristics in large arrays of test devices. Front end of line (FEOL) test structures include transistors of different sizes, number of polysilicon fingers, polysilicon fingers proximity, and orientation, for both NMOS and PMOS MOSFETs. Back end of line (BEOL) test structures include parasitic coupling, plane to plane and crossover capacitances, measured using a charge-based capacitive measurement (CBCM) methodology integrated with switches in the scan chain. The testing of the designed test chip has proven successful for both device and interconnect test structures.
(cont.) Different layout practices in both NMOS and PMOS transistors are seen to result in significant differences in mean and standard deviation of measured output current, with 95% confidence or more. The FEOL structure analysis shows strong dependencies between layout practices: orientation offers a consistent but opposite offset in NMOS and PMOS transistors and variation increases for gate lengths split among fingers. Variation due to sizing follows Pelgrom's model, showing that variation increases for smaller gate lengths and widths, in both NMOS and PMOS transistors. Threshold voltage extraction and variation analysis also demonstrate how variation increases for smaller features. BEOL capacitances were extracted and sub-femto Farad changes were detected for capacitive test structures. Spatial analysis reveals a large die-to-die trend in device performance. The parameter extraction and variation analyses made possible by the variation test chip enable the identification of likely variation sources, quantification of circuit impact and sensitivity, and specification of layout practices for variation minimization.
by Karen Mercedes González-Valentín Gettings.
Ph.D.
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Close, Joanne. "English auxilliaries : a syntactic study of contraction and variation." Thesis, University of York, 2004. http://etheses.whiterose.ac.uk/9870/.
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Whistler, Toni. "A study of the molecular variation between orbivirus proteins." Thesis, Rhodes University, 1985. http://hdl.handle.net/10962/d1003290.
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The aim of this study was to initiate a structural analysis of the capsid polypeptides from several serotypes of bluetongue virus in order to provide insight into the relatedness and possible origins of the different serotypes. Tryptic peptide mapping of ¹²⁵I-labelled group antigen by ion exchange chromatography was used to assess the structural relatedness of seven BTV serotypes from Southern Africa, North America and Australia. Each serotype had several tyrosine containing tryptic peptides which were unique, but approximately 35% of the peptides analyzed were found to be highly conserved between all 7 serotypes. BTV-20 appeared to be closely related to BTV-B and these two serotypes with BTV-4 and BTV-17 appeared to form a closely knit central cluster.KMBT_363
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Roberts, Nicholas Stephen. "A sociolinguistic study of grammatical variation in Martinique French." Thesis, University of Newcastle upon Tyne, 2015. http://hdl.handle.net/10443/2871.
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This thesis is the first quantitative sociolinguistic study of grammatical variation in the French département et région d’outre-mer (DROM) of Martinique. Although Canadian varieties of French have been extensively studied within a Labovian framework, there is currently a dearth of variationist research focusing on varieties genetically related to European French. My doctoral work aims to address this gap in the research literature by presenting a sociolinguistic description of selected aspects of the variable grammar in a previously under-researched variety of French. The data for the present study were extracted from a corpus of spoken Martinique French which comprises approximately 16 hours of semi-directed sociolinguistic interviews conducted between December 2010 and February 2011. The analysis is based on a judgment sample of 32 native islanders from the Saint-Pierre arrondissement in the Northwest of Martinique, who were stratified by age, sex and educational level. Due to high levels of French/créole martiniquais bilingualism, informants’ frequency of use of French in interpersonal communication was measured using a modified version of Mougeon and Beniak’s (1991) languagerestriction index. My thesis specifically focuses on three morphosyntatic variables, namely the alternation between doubled and non-doubled subject NPs, the use/non-use of the morpheme ne in verbal negation and the variable expression of future temporal reference. I investigate the overall distribution of variant forms and determine whether the constraint systems for other varieties of French also hold in a Caribbean context. I also test and compare a range of statistical methods currently used in variationist research with the aim of providing a more comprehensive picture of the variable grammar in this regional DROM variety. Fixed-effects logistic regression models demonstrate that this Caribbean variety exhibits patterns of variation that distinguish it from other French speech communities. Mixed models further reorder and refine the respective constraint hierarchies, demonstrating the importance of considering random effects—such as individual speaker or lexical verb—when analysing sociolinguistic data. The combination of these statistical tools thus allows me to assess the extent to which such random effects constrain variation in Martinique French grammar. By contrasting variable usage in Martinique with that reported for communities in mainland France and francophone Canada, my doctoral thesis provides a localised as well as a global perspective on French morphosyntactic variability. This study therefore contributes to our understanding of the linguistic and social factors that unite and divide the French-speaking world. As such, it adds a French perspective to the extant literature on global linguistic trends (Meyerhoff & Niedzielski 2003; Buchstaller & D’Arcy 2009).
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Lam, Tat-ho, and 林達豪. "Using variation theory to enhance students' capability in solving pedigree problems." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/208606.
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This thesis reports on a learning study that employed variation theory to enhance a domain-specific generic-capability pedigree analysis of Hong Kong secondary five students so as to help them develop their capability to solve pedigree problems. Pedigree analysis is a study of inheritance in genetics, which includes the deduction of dominant and recessive characters. The literature and local examination reports suggested that solving pedigree problems is difficult for students, as the process of deduction demands conceptual understanding and use of scientific language.
Three biology teachers participated in this learning study using variation theory. Teachers shifted the focus of lesson observation from teaching performance to student learning, to how students deduced the dominant character from pedigree problems, which was the object of learning. To explore the effectiveness of such teaching and learning to solve pedigree problems through different patterns of variation, two cycles of learning study were conducted in two senior biology classes. Results showed that students were more able to deduce the dominant character with relevant genetic principles by experiencing the variations. Both conceptual understanding and scientific language are critical aspects of solving pedigree problems. This study also suggests that explanatory scientific writing needs to be broken down into different components and then differentiated patterns of variation designed to let students discern those components and their relationships; in that way their writing can be ‘scaffolded’ in a stepwise manner rather than giving them the whole writing framework at once. However, the identification of critical features and patterns of variation and their relevance to the object of learning should be considered carefully and explored further.published_or_final_version
Education
Doctoral
Doctor of Philosophy
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Lindroos, Katarina. "Accessing Genetic Variation by Microarray Technology." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2002. http://publications.uu.se/theses/91-554-5251-5/.
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Tsoi, Hack-kie Philip, and 蔡克己. "Sources of variation in science achievement of Form two students." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1986. http://hub.hku.hk/bib/B42128304.
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Mahoney, Catherine R. "Anthropometric Variation in California: A Study of Native American Populations." The University of Montana, 2008. http://etd.lib.umt.edu/theses/available/etd-05082008-132023/.
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Physical anthropologists study the patterns of human morphology to observe the influence of genetics and environment on cranial form. The following study compares cephalic and nasal index means from four Native American populations using modern statistical methods, including one-way ANOVA tests and Games-Howell comparison tests. The individuals used were of only Native American ancestry, over the age of seventeen when the data was collected, and were divided into male and female samples. The climatic conditions of each of the regions are compared to examine the relationship between the mean cranial and nasal indices and the environments in which the populations lived. Previous research suggests that larger cephalic indices should be found in populations from colder climates and larger nasal indices should be found in populations from warmer climates. Some cases in which a significant difference in means was found between populations it followed the pattern predicted from the environmental differences, though one population (the Miwok) provided an exception.
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Mahoney, Catherine Rose. "Anthropometric variation in California a study of Native American populations /." CONNECT TO THIS TITLE ONLINE, 2008. http://etd.lib.umt.edu/theses/available/etd-05082008-132023/.
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Mitchell, Rebecca Alexandra. "A study in syntactic variation : mood usage in Gabonese French." Thesis, University of Cambridge, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.615819.
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Armstrong, Nigel Robert. "A study of phonological variation in French secondary school pupils." Thesis, University of Newcastle Upon Tyne, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358079.
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Klemola, K. J. "Non-standard periphrastic DO : a study in variation and change." Thesis, University of Essex, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336883.
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Karthigesu, Vassandra Devi. "A study of hepatitis B virus variation and antigenic variants." Thesis, Royal Veterinary College (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309416.
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Yu, Li S. M. Massachusetts Institute of Technology. "A study of through-silicon-via (TSV) induced transistor variation." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/66483.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2011.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 83-85).
As continued scaling becomes increasingly difficult, 3D integration has emerged as a viable solution to achieve higher bandwidth and power efficiency. Through-siliconvias (TSVs), which directly connect stacked structures die-to-die, is one of the key techniques enabling 3D integration. The process steps and physical presence of TSVs, however, may generate a stress-induced thermal mismatch between TSVs and the silicon bulk. These effects could further perturb the performance of nearby electronic structures, particularly transistors, diodes, and associated circuits. This thesis presents a comprehensive study to characterize, analyze and model the impact of TSV-induced stress impact on device and circuit performance and its interaction with polysilicon and shallow-trench-isolation (STI) layout pattern density. A test chip is designed with multiplexing test circuits providing measurements of key parameters of a large number of devices. These devices under test (DUTs) have layouts that explore a range of TSV and device layout choices in the design of experiments (DOEs). The test chip uses a scan chain approach combined with low-leakage and low-variation switches and Kelvin sensing connections, which provide access to detailed analog device characteristics in large arrays of test devices. A test circuit and an Ioff measurement method is designed to perform off-chip wafer probe testing measurement. In addition, a finite element analysis model is constructed to mimic realistic TSV structures and processes. A complete flow and methodology to analyze transistor characteristics and circuit performance under the influence of TSV stress is proposed. An efficient algorithm is also proposed to simulate full-chip circuit variation under the impact of TSV stress based on a grid partition approach. Test cases corresponding to the aforementioned test chip are simulated for comparison with measurement data.
by Li Yu.
S.M.
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Mokhberi, Shiva. "ELECTRICAL BIOIMPEDANCE CEREBRAL MONITORING : A Study of Cerebral Impedance Variation." Thesis, KTH, Skolan för teknik och hälsa (STH), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-190876.
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Stroke is amongst the leading causes of death and disability worldwide. Today diagnosis of Stroke is restricted to fixed imaging facilities which do not provide a rapid diagnostic. A portable device which could provide a non invasive assessment of stroke would therefore decrease the time of diagnosis and increase the chance of survival. Recent studies have confirmed that Implementing Electrical Bioimpedance in a portable device could provide a reliable means for Stroke diagnostic. However in order to be able to use the brain impedance as an indicator of Stroke, the invariance of brain impedance with time in healthy individuals should be studied first. Experimental Bioimpedance Spectroscopy (BIS) measurements from a healthy control group of 10 subjects have been used in this study to inspect the variation of brain impedance in the span of two weeks. The results of this study suggest that the cap which was used for brain impedance measurements together with the available device have not been an optimal way of measuring the brain impedance and therefore have affected the data by causing artifacts for the results. With the artifacts available in the data acquired in this study it is not possible to make any statements about the variation of brain impedance and therefore a deeper analysis of collected data using descriptive analysis is required in order to be able to judge on the significance of the obtained errors. In the future a larger study group should be considered in order to increase the predictive power of the observations.Stroke är bland de ledande orsakerna till död och funktionshinder i hela världen.I dagsläget är diagnos av stroke begränsad till fasta bildenheter som inte möjliggör en snabb diagnos. En bärbar enhet som möjliggör en icke invasiv bedömning av sjukdomen skulle minska diagnos tiden och följaktligen öka chansen att överleva sjukdomen. Genomförda studier i ämnet har bekräftat att implementering av Electrical Bioimpedance i en bärbar enhet kan räknas som ett effektivt sätt för Stroke diagnostik. För att kunna använda hjärnans impedans för Stroke diagnostik, bör först en studie av hjärnans impedans på friska individer utföras för att kunna visa att impedansen är oförändrad med tiden. Experimentell Bioimpedans Spektroskopi (BIS) mätningar från en frisk kontrollgrupp av 10 försökspersoner har utförts i denna studie för att inspektera variationen av hjärnans impedans under två veckor. Resultaten från denna studie tyder på att sättet av impedans mätningen i dagsläget är inte optimalt. Artefakter presenterad i resultatet gör det omöjligt för att kunna komma till ett beslut om hjärnans impedans variation . För fortsätta studier bör man överväga en större kontrollgrupp och även en analysering av data med hjälp av t-statistik som var inte inom ramen av denna studie.
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Malhotra, Anita. "What causes geographic variation? : a case study of Anolis oculatus." Thesis, University of Aberdeen, 1992. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU065684.
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The lizard Anolis oculatus, endemic to the small Lesser Antillean island of Dominica, was selected as a model to study the causes of geographic variation. Patterns of geographic variation were investigated using a variety of univariate, bivariate and multivariate numerical methods. Patterns were found to be predominately clinal, with some incongruence within and between the character systems (body proportions, scalation, and colour pattern), and included altitudinal, east-west and (on the Caribbean coast) north-south clines. Overall four ecotypic groups were recognisable, and the current subspecies were invalidated. Simultaneous Mantel tests pointed strongly to adaptation to various environmental factors (both biotic and physical) as the cause of variation in most of the characters studied. Canonical correlation analysis was used to study the covariance of character constellations and their relationship to environmental variation. A closely related species from a neighbouring island with an independent evolutionary history, A. marmoratus from Basse Terre (Guadeloupe) showed many parallels, both in patterns of geographic variation and associations with environmental variation, which can be attributed solely to the effect of current ecology. A direct test of the action of natural selection was then provided by a translocation experiment in Dominica, where representative populations of the four ecotypes were translocated into a single habitat. In a very short period, evidence was obtained of strong directional selection acting proportionately to the extent of ecological change experienced by the different ecotypes.
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Lundmark, Per Erik. "Genetic and Genomic Analysis of DNA Sequence Variation." Doctoral thesis, Uppsala universitet, Molekylär medicin, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-158486.
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The studies in this thesis describe the application of genotyping and allele specific expression analysis to genetic studies. The role of the gene NPC1 in Triglyceride metabolism was explored in mouse models and in humans on the population level in study I. NPC1 was found to affect hepatic triglyceride metabolism, and to be relevant for controlling serum triglyceride levels in mice and potentially in humans. In study II the utility of the HapMap CEU samples was investigated for tagSNP selection in six European populations. The HapMap CEU was found to be representative for tagSNP selection in all populations while allele frequencies differed significantly in the sample from Kuusamo, Finland. In study III the power of Allele specific expression as a tool for the mapping of cis-regulatory variation was compared to standard eQTL analysis, ASE was found to be the more powerful type of analysis for a similar sample size. Finally ASE mapping was applied to regions reported to harbour long non-coding RNAs and associated SNPs were compared to published trait-associations. This revealed strong cis-regulatory SNPs of long non-coding RNAs with reported trait or disease associations.
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Lam, Siu-yan, and 林少欣. "The use of variation theory to improve student understanding of acids and bases." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B30192341.
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Pang, Ming-fai, and 彭明輝. "Making learning possible: the use of variation in the teaching of school economics." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31243502.
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Huang, Rongjin, and 黃榮金. "Mathematics teaching in Hong Kong and Shanghai: a classroom analysis from the perspective of variation." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31244245.
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Kwong, Siu-po Eve, and 鄺小寶. "The use of variation theory in developing students' critical thinking skills." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B3554207X.
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Beswick, Jaine Elizabeth. "The velar nasal in Galicia : case-study of a linguistic variable in a bilingual community." Thesis, University of Bristol, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311340.
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Rollins, Sarah. "The Salt Lake Tabernacle : acoustic characterization and study of spatial variation /." Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd1113.pdf.
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Brato, Thorsten [Verfasser]. "Variation and Change in Aberdeen English : A Sociophonetic Study / Thorsten Brato." Frankfurt a.M. : Peter Lang GmbH, Internationaler Verlag der Wissenschaften, 2016. http://d-nb.info/1123420548/34.
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Sangster, Catherine M. "Inter- and intra-speaker variation in Liverpool English : a sociophonetic study." Thesis, University of Oxford, 2002. http://ora.ox.ac.uk/objects/uuid:6d5cbd34-73ab-4c22-b341-9253eac94b3c.
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This thesis presents experiments and interviews which investigate pronunciation variation in the Liverpool accents of young speakers. Experiment One investigates inter-speaker variation, Experiment Two investigates intra-speaker variation, and Experiment Three investigates both inter- and intra-speaker variation. These three experiments are conducted from a sociophonetic perspective, with controlled elicitation of natural speech and acoustic analysis of speech data. The experimental investigations are complemented by interviews, which incorporate the perceptions and opinions of speakers of Liverpool English into the study. The study makes several contributions to the field of sociolinguistic research. It provides a new examination of Liverpool English. Experiment One is specifically designed to explore one of its most complex and ill-defined phonetic features, the realisation of plosives as affricates or fricatives. In addition to this phonetic investigation, Experiment One also examines sociolinguistic variation in this feature, and shows that speakers' individual attributes (such as their social networks and their plans for the future) are as relevant to variation as their socio-economic status. The study also makes important methodological contributions. Instrumental phonetic techniques and standards are successfully applied to sociolinguistic investigation conducted in the field. An interdisciplinary approach, bringing together qualitative interviews and sociophonetic experiments, is adopted. A new quiz-questionnaire technique for data collection, which should prove useful for many kinds of future sociolinguistic research, is developed for Experiment Three. Finally, Experiment Three tests many accounts and models of intra-speaker variation. Speakers are shown to vary their pronunciation as the speech situation varies, but not all the seven phonetic variables investigated show the same patterns of variation. Speakers vary their pronunciation according to audience, and also according to topic. Speakers with a high level of ambition vary their pronunciation of certain phonetic variables more than those with a lower level of ambition, and female speakers vary their pronunciation more than male speakers.
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Lockhart, Matthew S. M. Massachusetts Institute of Technology. "A transit-timing variation study of the extrasolar planet TrES-3." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/53108.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2009.Includes bibliographical references (p. 105-106).
Portable Occultation Eclipse and Transit System (POETS) detectors [7] mounted on the Wallace Astrophysical Observatory (WAO) 0.8m and NASA Infrared Telescope Facility (IRTF) 3m telescopes are used to observe five stellar transit events of the extrasolar planet TrES-3 [5]. Model light curves are fit to the five data sets and transit midtimes are determined. Midtimes obtained in this study, along with midtimes reported by Sozzetti et al. (2008) [8], are compared to the ephemeris of the planet. The transit timing variation (TTV) of each midtime is calculated. Based on these data the presence of a third body in the TrES-3 system cannot be determined. Mass and period of a hypothetical perturbing body are calculated for several illustrative cases.
by Matthew Lockhart.
S.M.
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DeLucia, Dominic. "A Parametric Study on Power Variation for Model Wind Turbine Arrays." PDXScholar, 2013. http://pdxscholar.library.pdx.edu/open_access_etds/1120.
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This thesis presents the results of wind tunnel experiments performed for various model wind turbine arrays. The aim is to understand how siting affects power output. To optimize wind farm efficiency the experiments vary the parameters of the model wind turbines and the layout of the wind turbine array. The parameters include the alignment, height, spacing, and the rotational direction of the model wind turbines. These experiments employ mechanical torque sensors to simultaneously measure the torque and rotor angular velocity, which yields a direct measurement of the fluid mechanical power extracted by the turbine at multiple locations. For a 4 × 3 array, the power is calculated at the center turbine in each of the rows. Variations in wind farm efficiency ranging from 55% to 90% are observed between the 13 different layouts tested. Modifications to the layout of the wind turbine array clearly affects the power output of the wind turbines downstream. The results of such experiments highlight the importance of studying the relationship between wind farm layout and power output.
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Yamamoto, Keiko. "Study on regional scale mass variation using GRACE satellite gravity data." 京都大学 (Kyoto University), 2007. http://hdl.handle.net/2433/59309.
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Trousdale, Graeme Murray. "Variation and (socio)linguistic theory : a case study of Tyneside English." Thesis, University of Edinburgh, 2000. http://hdl.handle.net/1842/22698.
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This thesis is concerned with the relationship between (a) patterns of sociolinguistic variation and (b) issues in theoretical linguistics. The patterns of sociolinguistic variation are derived from data collected from twenty speakers of Tyneside English. The recordings of the speakers were made broadly following a social network model, divided to sample the speech community along parameters of age and gender. The issues in theoretical linguistics concern the semantics and (morpho)syntax of modal verbs in English, and the phonological behaviour of the oral stops in specific linguistic environments. The thesis aims to show how a holistic approach to variation in the speech community, informed by knowledge of both sociolinguistic and formal linguistic theory, can best account for the data. The introduction expands on the aims of this thesis, and provides a more detailed synopsis of the materials in each chapter than is given in this abstract. Chapter 1 briefly summarises certain aspects of the historical evolution of the Tyneside English (TE) accent, along with some analysis of TE syntactic and morphological patterns, to set the main discussion of the variables in the following chapters within a wider context. Chapter 2 provides a discussion of the semantics and (morpho) syntax of the modal verbs in standard English, with some commentary on relevant aspects of the historical evolution of the modals, which draws on theoretical aspects of both the Principles-and-Parameters and Minimalist frameworks. Chapter 3 examines patterns of glottalisation and glottaling in English, with specific reference to previous studies of TE, as well as to relevant work in current phonological theory, particularly Lexical and Metrical Phonology, along with a selective investigation into the historical evolution of these phenomena in TE (using material from the Survey of English Dialects) and other varieties of British English. Chapter 4 considers the issue of gender-based variation and its implications for linguistic maintenance and change. Chapter 5 presents a detailed discussion of the methodology used for the collection of data for this thesis, as well as an analysis of the data itself, and how these data correlate with the various social groups.
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Kuo, Chia-Chi, and 郭家吉. "Gauge Variation Study for Ordinal Data." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/36277503622344684780.
Full textAbstract:
碩士國立成功大學
統計學系碩博士班
95
Recently, gauge variation study has been highly regarded by the quality practitioners when QS9000 and TS16949 become fashionable requirements for manufacturing industries. Measurement plays a significant role in helping organizations improve their product quality. Good quality of products is the key factor of business success. Therefore, how to ensure the quality of measurement becomes an important task for the quality practitioners. Gauge variation study can be divided into two parts by data types; continuous data and attribute data. Especially, attribute data also can be divided into three parts; ordinal data, binary data and the data follows Poisson distribution. Therefore, the main purpose of this research lays stress on ordinal data. In food industries, sensory evaluation is increasing in importance because of the present economic emphasis on consumer needs and wants. However, the consistency within panelists and between panelists may affect the reliability of sensory evaluation. Therefore, in performing the gauge variation study for ordinal data, most food industries are using Kappa and Kendall concordant coefficient stipulated by QS9000. A comparative analysis has been conducted for evaluating the accuracy of gauge variation study among two methods (Kappa and Kendall). Moreover, the rationale for a proper choice of the number of panelists (b), the sample size (n) and replicate measurement (r) is discussed. Hopefully, it can provide a useful reference for the food industries.
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LIU, WEI HSUAN, and 劉蔚萱. "A Study of Variation Technique and Interpretation in Copland 's Passacaglia and Piano Variations." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/64218994081737743675.
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"Developing approaches to study human epigenetic variation." THE JOHNS HOPKINS UNIVERSITY, 2007. http://pqdtopen.proquest.com/#viewpdf?dispub=3267881.
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Chen, Chia-Miao, and 陳佳妙. "Study on Somaclonal Variation of Phalaenopsis Orchid." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/32199096586823189693.
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Shu-Ching, Chang, and 章淑靜. "The Study of Renminbi Exchange Rate Variation." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/32711232748560400081.
Full textAbstract:
碩士淡江大學
中國大陸研究所
92
In recently, grows along with the China economy. The Renminbi exchange rate maintenance was invariable, also peg US dollar exchange rate system, enabled the Renminbi exchange rate to have underestimated. Since 2003, international funds have continued to flow in the Asian area. Besides the Renminbi, Asian currency gradually hastens the revaluation. The Renminbi exchange rate subject on international receives the attention. This research will make the induction and analysis in view of the international society regarding the Renminbi exchange rate commentary. And discussion the Renminbi exchange rate change will have the influence regarding the mainland China overall economy and the Taiwan merchant investment in mainland China. Viewed from the foreign exchange reserves that, grows along with the China economy, 2003 year''s end have amounted to 4,033 hundred million US dollars. Enables the Renminbi to have the revaluation pressure. The Chinese central bank for the maintenance Renminbi stabilization of exchange rate, release currency to purchase foreign exchange, causes M2 to grow excessively quickly in 2003. This situation will create the inflation pressure. The international society comments the aspect, because Renminbi exchange rate underestimating, the indirect exportation similar product national exportation drops. Exerts pressure in abundance to mainland China anticipated the Renminbi revaluation. This also makes the massive speculative capitals to enter the Chinese arbitrage. The Renminbi revaluation possibly exports the product to China to cause the damage. Because mostly are the labor force crowdedness commodity, wins by the price superiority. After the revaluation will be able to reduce its international competition strength. On the other hand, may reduce the import raw material price. From the experience of Asia''s crisis, the China government still controls its foreign exchange system strongly. At present the Chinese government also takes many related measures to reduce the revaluation pressure. Like relaxes the fund control, enhances the reserves rate, QDII and so on. At the beginning of 2004, to prevent economically excessively hot picks, takes macroeconomic regulation and control measures to reduce excessively invests. At present China still intended to maintain the stable exchange rate standard. And avoids the Renminbi exchange rate change having excessively many negative influences to the Chinese itself economy.
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Wu, Ming-Ju, and 吳明珠. "Moving and Variation—Study on Ink Paintings." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/z427s8.
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碩士國立臺中教育大學
美術學系碩士在職專班
107
The two concrete objectives of the study include: (I) to probe into the context and source of moving and variation and ideas related to the aesthetics of variation; (II) to experiment and create with multiple methods in the author's three series of ink paintings on the theme of moving and variation. The works of the study were created between 2014 and 2017, and they formally include the depiction and moving of characters whose faces are simplified or transformed and space-time motion. Additionally, they integrate cubism and surrealism and use block segmentation and deformation and misplacement to place her works between concrete and semi-concrete. The three series of the author’s creations include: (I) motion series—a total of six works in this series show movers that do not stop moving in space-time through philosophical thought in Book of Changes with variable and changeable divinatory symbols and colors representing five elements. (II) person and object series—a total of five works in this series blend Oriental and western artistic nutrients and transform them. Additionally, the methods of misplacement, moving, restructuring and segmentation are used to manifest the transfer and change of time, space and mental states with various symbols. (III) imperial book series—a total of six works in this series focus on the Chinese zodiac and express the idea of free thought with blank and concave-convex codes following the overlapping of kneading, papermaking and coloring. iii The accumulation of experience in this creation improved the author’s concepts as in the following three aspects: (I) as long as there is new thought, both old and new tools do not impede the development of creation, (II) from the level of “spirit of creation,” she can distinguish the styles and features of modern ink painting from those of traditional ink painting; (III) the first requirement of the expression of art is one’s inner thought, not merely practiced skills. Keywords: moving, variation, modern art.
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蔡佩珊. "A study of application of variation and interpretation in Martinů's variations on a Theme of Rossini." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/77265744372029516879.
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Ding, Jihui. "Experimental Study on Rock Deformation and Permeability Variation." Thesis, 2013. http://hdl.handle.net/1969.1/151377.
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The development of a petroleum reservoir would inevitably induce a rearrangement of the in-situ stress field. The rearrangement of the stress field would then bring about a deformation of the reservoir rock and a change of the permeability. This experimental study was carried out to investigate rock deformation and its impact on axial permeability. Triaxial compression tests were conducted on Berea sandstone, Indiana limestone, Westerly granite and tuff specimens. Axial permeability was continuously measured for Berea sandstone and Indiana limestone during triaxial compression tests. The axial permeability of fractured Westerly granite specimens was also measured during hydrostatic compression tests. Acoustic emission (AE) monitoring was performed to help improve the understanding of rock deformation. Results showed that Berea sandstone and Westerly granite were relatively brittle, while Indiana limestone and tuff were relatively ductile. Rock deformation altered pore structures and the change of pore structures considerably impacted fluid flow through rock. For porous Berea sandstone and Indiana limestone, the destruction of the pore structure by rock deformation led to a decrease in axial permeability. For tight Westerly granite, fractures created by rock deformation significantly improved the ease of fluid flow. Acoustic emission response was found to be strongly dependent on rock type. Brittle Berea sandstone and Westerly granite produced high AE rates during compression tests, while ductile Indiana limestone and tuff generated very low AE rates.
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Chang, Chien Shui-Wen, and 張簡水紋. "Study on Micro-scale Variation of Soil pH." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/80914822903018377636.
Full textAbstract:
博士國立中興大學
土壤環境科學系
88
There are spatial variations of physical, chemical, and biological properties in soil environment. The growth and nutrient uptake of plant roots are directly influenced by soil pH. Additionally, growth and development of plant roots are mainly in soil’s macro-pores. Root excretions, organic matter decomposition, mineral weathering, and leaching are the four major factors affecting micro-scale soil pH variation. It is, thus, important to understand the micro-scale variations of soil pH. The pH of soil pastes measured by glass membrane electrodes can’t represent the micro-scale variation of pH in soil environment. In the present study, the soil pH in macro- and micro-pores were measured by an ISFET pH microelectrode. The associated physical and chemical properties were also determined. Further, the causes of variation, ranges of micro-scale soil pH variation at three major soil orders in central Taiwan were discussed. The effects of upland and paddy field cultivation on these distributions were also investigated. The results indicated that macro-pore soil pHs were significantly lower than those of micro-pores in long-term uncultivated lands as a result of cations leaching from macro-pores were greater than micro-pores. The macro-pore soil pHs were also lower than those measured by soil paste. Moreover, micro-scale variation of soil pH was greater at depth of 20-30 cm than at that of 30-40 cm. Due to the difference in rain infiltration, micro-scale variation of soil pH was greater in flat than in slope topography. The extents of micro-scale variation of soil pH of both upland and paddy fields were smaller than that of long-term uncultivated field. However, the pH of macro-pore was greater than paddy fields. This is due to the large amount cations input by irrigation water. The means of measured macro-pore pH of paddy soils of Ultisol, Oxisol, and Inceptisol were 0.5, 0.4, and 0.2 units higher than 1:1 soil paste, respectively. The pH of macro-pore was lower than upland fields. Due to lesser irrigation and fertilizer application, the means of measured macro-pores pH of dry farmland soils of Ultisol, Oxisol, and Inceptisol were 0.6, 0.5, and 0.4 units lower than 1:1 soil paste, respectively. The order of micro-scale soil pH variation of investigated soils were: TTr, TWz, and TCo series of Ultisol > TWt and CCe series of Oxisol > Eh, Ph, Cl, Co, Ts, and Sn series of Inceptisol. To sum up, leaching is the main mechanism causing micro-scale soil pH variation. Consequently, the related soil factors, such as bulk density, porosity, and base saturation of soils prominently affect micro-scale soil pH variation. Moreover, for non-calcareous soils, the variation of micro-scale soil pH increased as texture stratification and mottles in soil increased.
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Hsu, Shih-ming, and 許世明. "A study of variation order of construction contract." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/30401074748937083908.
Full textAbstract:
碩士東吳大學
法律學系
93
Disputes of construction variation order occur very often and become the major problem in practice. This paper starts with introducing basic concepts and key elements of construction contract. In further discusses about the rationale, purpose to form the legal system and its limitation. This paper attempts to distinguish the ambiguity concepts such as extras, change order claims, constructive change from variation order. As for differing site condition, this paper introduces the preliminary concepts as well. This paper begins to discuss the issue of risk management and risk allocation after the basic concepts was clearly distinguished. In generally, the owner should take the risk of variation order from the three major aspects discussed in the paper including change order, extras, and differing site condition（under the premise when the contractor can’t foresee the situation）. In further, this paper compares the standard form of contract form U.S.A and Japan to analyze the defects and advantage of each contract. This paper put emphasis on the extensively approach to the problems of substantial and procedural. The discussion of procedural issues mainly includes the start and end point of the variation order, the role of contracting officer and engineer, issues of the owner failure to fulfill its obligation, oral change, and issues of the permission of superior organization. The discussion of substantial issues mainly includes how to claim the owner and what kind of claim to adopt, deletion of contract work, the price adjustment of new contract items. In the end, this paper indicate the problems in practice about change variation and differing site condition concerning insurance and provide its opinion to be a reference in practice.
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陳猛飛. "Study of process variation on P3HT-Based OTFTs." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/85869978277581240961.
Full textAbstract:
碩士國立交通大學
電機學院微電子奈米科技產業專班
97
A procedure is studying and using the solution-process to fabricate P3HT-based organic thin film transistor. Using appropriated solvent and weight percentage is needed. And then the P3HT solution will be spun and deposited to be as active layer for organic electronic. P3HT organic material is to be classified to conjugated polymer. One of advantages is a property of self-organization and based on this structure to form a long chain. This long chain will be formed a lamella structure. If this lamella were packing closely, it would result a high regioregularity, which could obtain high mobility. Due to different process method, this lamella will be formed edge-on or face-on result. In my experiment, First of all, using chloroform to be a solvent with 0.1 weight percentages to fabricated OTFT can obtain better performance than xylene made, due to solubility and like dissolves like. Subsequently, we study the difference between regioregularity and molecular weight, two solutes were purchased from two different companies, dissolved them in the same solvent, chloroform. The result is that the difference of molecular weight is more importance than regioregularity. Moreover, fabricated by spin speed at 1500rpm and curing at 150℃ for 3 minutes can exhibit optimized result and in the meantime, observe that the oxygen concentration is less and less in the thin film analyzed by Auger electronic and ECSA surface elemental. Known a basic process procedure, there is a Schottky barrier between metal and organic material resulting less the current transport. However, S/D deposited with gold and an appropriated adhesion layer can reduce this barrier height, due to their closest work function and surface chemical property. In addition to previous results, to use surface treatment (HMDS) is a good idea to improve the packing and ordering for strong chain interaction and lead to exhibit high mobility and approximate to VG=0 of threshold voltage. In end of this thesis, we discuss about stability characteristics. Storage in the atmosphere, all of organic material will degrade as time goes by. This result is the same as P3HT polymer when it has been stored for one month. But the off current can be “healed” by annealing process at 180℃ for 30 minutes in furnace with N2 flow. Extra, low molecular weight comes to the same thing. Meanwhile, a device undergoing a serious process procedure can obtain a better performance, too. The on/off ratio is improved from 6x104 to 8~6x106; suspect that oxygen molecule can be driven off during annealing process. Unfortunately, the mobility is not to be improved and reduce down to 0.3x10-3 from 6x10-3 slightly and Vth is shifted to more negative, due to chain torsion. Last, constant voltage stress is applied to see how the drain current change. During stress, the drain increases with stress time going by when only drain electrode is applied at -60 voltages. There is no any gate current to be observed. We find out that the basic electrical result of the same device is changing after stress. A slight movement in off current, compared with just annealing one. So we suspect that the oxygen may diffuse into the film during stress.
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"Study of cosmic ray variation in Hong Kong." 2012. http://library.cuhk.edu.hk/record=b5549200.
Full textAbstract:
以香港為重點，我們對於地表和地下中由地球圈內因子所引致的宇宙射線變化進行了研究。借用圖像重建演算方法，我們定立了一種可於格狀排列的宇宙射線探測器觀測中重塑宇宙射線分佈的方法，並將其用於香港仔隧道實驗室的渺子探測器中。其結果表明地形對地下宇宙射線分佈的影響。
在地面上，我們用微擾蒙地卡羅方法研究了大氣變化對地表宇宙射線的影響。由此我們得到了一考慮到所有高度的空氣密度以還原大氣變化對地表宇宙射線影響的修正方案。
我們亦演算了宇宙射線粒子在地球磁場內的軌跡，並以探測器收納向量的概念，表達地面儀器所觀測的宇宙射線量與地球以外的原初宇宙射線之關係。
最後，藉我們對地球圈內做成宇宙射線變化的眾因子之認識，我們試圖還原它們的作用，以使我們能於地表宇宙射線觀測中探測地外原初宇宙射線的變化。我們的結果表明，在地表宇宙射線中的晝夜變化，有部分是由宇宙中的原初宇宙射線淨流引起。
Cosmic ray (CR) variations of terrestrial origin were examined, with focus on Hong Kong at both the surface and underground.
Using image reconstruction algorithm, we developed a method to reconstruct CR distribution with measurement from a gridded CR detector, which we then applied to the muon tracker in the Aberdeen Tunnel Lab. The result demonstrated the eect of landscape on underground CR distribution. The good agreement between the measured CR distribution and MUSIC simulation validates the use of such simulation for other underground laboratories.
At the surface, we used perturbative Monte Carlo method to study the effect of atmospheric variations on surface CR counts. The result was a correction scheme to eliminate atmospheric variation in surface CR counts that took the air density at all height levels into consideration.
We also used particle tracing techniques to study the motion of CR particles in Earth’s magnetic field, and how CR counts from surface detectors are related to primary CR beyond Earth through the concept of detector acceptance vector.
With our understanding of CR variations of terrestrial origin, we attempted to undo their effects, and probe primary CR with surface CR observations. Our results suggested that parts of the diurnal variation in surface CR count are related to net streaming in the primary CR.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Chan, Yat Long = 在香港的宇宙射線變化研究 / 陳日朗.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2012.
Includes bibliographical references (leaves 91-95).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstracts also in Chinese.
Chan, Yat Long = Zai Xianggang de yu zhou she xian bian hua yan jiu / Chen Rilang.
Abstract --- p.i
Acknowledgement --- p.iii
Chapter 1 --- Introduction --- p.1
Chapter 2 --- Background --- p.3
Chapter 2.1 --- Primary and secondary cosmic ray --- p.3
Chapter 2.2 --- General review on CR variation --- p.5
Chapter 2.2.1 --- Variation in time --- p.5
Chapter 2.2.2 --- Variation in directions --- p.6
Chapter 2.3 --- CR variation of extra-terrestrial origin --- p.6
Chapter 2.3.1 --- Forbush decrease --- p.6
Chapter 2.3.2 --- CR co-rotation with sun --- p.7
Chapter 2.3.3 --- CR variations and periodic solar activities --- p.8
Chapter 2.3.4 --- Anisotropy of galactic origin --- p.9
Chapter 2.4 --- CR variations of geomagnetic origin --- p.9
Chapter 2.4.1 --- Geomagnetic cut off at different latitudes and longitudes --- p.9
Chapter 2.4.2 --- East-West asymmetry --- p.10
Chapter 2.4.3 --- Time variations of geomagnetic cut-off --- p.10
Chapter 2.5 --- CR variations of atmospheric origin --- p.12
Chapter 2.6 --- CR variations from lab overburden --- p.14
Chapter 2.7 --- Round Up --- p.15
Chapter 3 --- Muon directional variations in Aberdeen Tunnel Lab --- p.17
Chapter 3.1 --- Introduction --- p.17
Chapter 3.1.1 --- The Aberdeen Tunnel Lab --- p.17
Chapter 3.1.2 --- The muon tracker --- p.18
Chapter 3.2 --- Simulation of muon directional distribution --- p.19
Chapter 3.3 --- Reconstruction of muon directional distribution --- p.21
Chapter 3.3.1 --- Image restoration analogy --- p.21
Chapter 3.3.2 --- Damped Richardson-Lucy deconvolution algorithm --- p.23
Chapter 3.3.3 --- Obtaining the PSF --- p.24
Chapter 3.3.4 --- Reconstruction result --- p.25
Chapter 3.4 --- Comparison of simulation and reconstruction --- p.26
Chapter 3.5 --- Conclusion --- p.29
Chapter 4 --- Simulating Cosmic Ray variations at Ground Surface --- p.30
Chapter 4.1 --- Scope of study --- p.30
Chapter 4.1.1 --- Geomagnetic variation --- p.30
Chapter 4.1.2 --- Atmospheric variation --- p.31
Chapter 4.2 --- Layout of Simulation --- p.31
Chapter 4.3 --- Modelling of Primary CR --- p.32
Chapter 4.4 --- Modelling of Earth's magnetic field --- p.35
Chapter 4.5 --- Modelling of atmosphere --- p.36
Chapter 4.6 --- Modelling of lab overburden --- p.37
Chapter 4.7 --- Modelling of Physics in cosmic ray cascades --- p.37
Chapter 4.8 --- Counting considerations --- p.38
Chapter 4.9 --- Monte Carlo speed up --- p.39
Chapter 4.9.1 --- Primary particle event biasing --- p.41
Chapter 4.9.2 --- Weight window technique --- p.41
Chapter 4.10 --- Differential operator sampling --- p.44
Chapter 4.10.1 --- Finite perturbation --- p.44
Chapter 4.10.2 --- In nitesimal perturbation --- p.45
Chapter 4.11 --- Simulation Result --- p.48
Chapter 4.11.1 --- Rigidity map at HK --- p.48
Chapter 4.11.2 --- Zenith angle dependence of muon flux --- p.50
Chapter 4.11.3 --- Density correction coefficients --- p.51
Chapter 5 --- Analysis of surface CR data --- p.55
Chapter 5.1 --- Detector description --- p.55
Chapter 5.1.1 --- The CUHK Muon Telescope --- p.55
Chapter 5.1.2 --- The Nagoya Multi-Directional Muon Telescope --- p.56
Chapter 5.2 --- Characterizing the detectors --- p.58
Chapter 5.2.1 --- Coupling function for rigidity --- p.60
Chapter 5.2.2 --- Acceptance vectors of detectors --- p.60
Chapter 5.2.3 --- Sensitivity towards Atmospheric conditions --- p.64
Chapter 5.3 --- Time series of surface CR data --- p.65
Chapter 5.4 --- Diurnal variations in CR data --- p.67
Chapter 5.5 --- Inferring CR streaming from surface measurement --- p.69
Chapter 6 --- Conclusion --- p.75
Chapter A --- Density correction coefficients and averaged atmospheric profile --- p.77
Chapter B --- Acceptance vector of the detectors --- p.87
Bibliography --- p.91