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

Study on the adaptation to impacts of land subsidence in Chiangyuan area, Pingtung, Taiwan

Chi, Chia-Fa 26 August 2009 (has links)
Land subsidence is a common phenomenon worldwide. When mitigation has approached a limitation, adaptation becomes an important strategy for sustainable development. Specially, climate variability and changes can make more serious impacts on coastal areas. This study focused on adaptation to land subsidence in Chiangyuan area consisting of several coastal villages, Pingtung county, Taiwan. Little research about the adaptations had been done in this area, except there was some studies for its awareness. Using a case study approach with questionnaires, in-depth interview, direct observation, this study explored past and existed adaptation behaviour in different categories of stakeholders. Moreover, we also tried to analyze the capacity of these adaptation for future impacts from land subsidence and flood made by climate change, and could increase the capacity. The results have revealed local people in Chiangyuan area had abundant experiences on adaptations to land subsidence and flood. They used different kinds of adaptation at same time to cope with flooding, land loss, and salted land problems. The followings have summarized the adaptation of four categories of stakeholders. 1. for local citizen, the major adaptation is house-elevating, who didn¡¦t adopt house elevating were without budget or planning to move out. 2. for farmer, planting economic fruits with higher tolerance to salt-water. 3. for aquaculture, fish-pond elevating, harvesting earlier, or building fish-pond on higher land. 4. for school, using water-proof gates or no classes during flooding. Some suggestion focused on adaptation to land subsidence was also given in this study, specially for government.
52

Digital Timing Control in SRAMs for Yield Enhancement and Graceful Aging Degradation

Neale, Adam January 2010 (has links)
Embedded SRAMs can occupy the majority of the chip area in SOCs. The increase in process variation and aging degradation due to technology scaling can severely compromise the integrity of SRAM memory cells, hence resulting in cell failures. Enough cell failures in a memory can lead to it being rejected during initial testing, and hence decrease the manufacturing yield. Or, as a result of long-term applied stress, lead to in-field system failures. Certain types of cell failures can be mitigated through improved timing control. Post-fabrication programmable timing can allow for after-the-fact calibration of timing signals on a per die basis. This allows for a SRAM's timing signals to be generated based on the characteristics specific to the individual chip, thus allowing for an increase in yield and reduction in in-field system failures. In this thesis, a delay line based SRAM timing block with digitally programmable timing signals has been implemented in a 180 nm CMOS technology. Various timing-related cell failure mechanisms including: 1). Operational Read Failures, 2). Cell Stability Failures, and 3). Power Envelope Failures are investigated. Additionally, the major contributing factors for process variation and device aging degradation are discussed in the context of SRAMs. Simulations show that programmable timing can be used to reduce cell failure rates by over 50%.
53

The influence of task variables on psychomotor performance variability

Maxwell, Randy Clyde 08 1900 (has links)
No description available.
54

Does the memory effect influence individual exponents in psychophysical power functions?

Wall, David C. January 1977 (has links)
Two groups of subjects made magnitude estimations of a series of eight circles, each of which had its own color. All subjects received the same number of presentations in both sessions, with half the subjects receiving the same size-color pairing of the first session, and the remaining subjects receiving a different size-color pairing, in the second session, one week later. Interrepetition correlations of exponents for the middle four adjacent presentations were computed. All of the correlations were significantly different from zero with the exception of the intersession correlation of the control group. The control group exhibited a significant decrease in correlation across sessions while the experimental group remained stable. These findings were totally unexpected. A test of difference between intersession correlations was not significant. The results can not easily be explained within the framework of either the response bias or memory hypotheses.
55

Blastocystis u prasat / Blastocystis in pigs

HORSKÁ, Ivana January 2011 (has links)
Blastocystis is an obligately anaerobic protist, commonly found in intestinal tract of numerous animals and humans across whole world. It is genetically very variable and rather enigmatic organism. Many aspects of its biology need to be further studied and clarified. On a chosen farm were during the year 2010 collected samples of pig faeces for parasitological survey. A total number of 40 samples was collected and cultivated by the method of Dobel-Leidlaw (1926). Of them, 19 was positive for Blastocystis. Other samples were checked by molecular methods (PCR). Using them, five Blastocystis sequences were obtained, which clearly belong to subtypes 1 and 5.
56

Characterisations of different El Nino types, their physical causes and predictions

Lai, Wang Chun January 2018 (has links)
El Niño Southern Oscillation (ENSO) is the most important interannual mode of climate variability in the tropical Pacific affecting the globe through teleconnections. The evolution of ENSO is studied with focus on individual El Nino (EN) events; factors and processes explaining the behaviours of different EN flavours are identified. The comparison to model simulations reveals a number of biases that explain differences in model behaviour. Based on reanalysis data, ENs are divided into Central Pacific (CPEN), Eastern Pacific (EPEN), and Hybrid (HBEN). ENs are found to form a continuous spectrum of events with CPEN and EPEN as its end members depending on: (1) the Western Pacific subsurface potential temperature anomaly (PTA) about 1 year before the EN peak, and (2) the Western to Central Pacific cumulative zonal wind anomaly (ZWA) between the onset and peak of the EN. Using these two parameters, about 70% of the total variance of the maximum EN SSTA can be explained up to 6 months in advance. ZWA describes the potential for triggering Kelvin waves for a given initial West Pacific recharge state as captured by PTA. A cross-validated statistical model is developed to hindcast the 1980-2016 Nov-Dec-Jan (NDJ) mean Niño3.4 SSTA based on the two parameters. The model is comparable to, or even outperforms, many NOAA Climate Prediction Centre's statistical models during the boreal spring predictability barrier. The explained variance between observed and predicted NDJ Niño3.4 SSTA at a lead-time of 8 months is 57% using five years for cross-validation. Predictive skills are lower after 2000 when the mean climate state is more La Niña-like due to stronger equatorial easterly ZWA caused by an intensification of both, Walker and Hadley cell. The ability of climate models to simulate and predict EN is assessed with data from the Climate Model Inter-comparison Project 5 (CMIP5). Most models are able to capture the main features of different EN types. But models struggle to reproduce large intensity ENs as found in observations. This issue can be traced back to a failure to realistically simulate the oceanic recharged state and the subsequent Kelvin waves for intense EN. Causes of EN involve Kelvin waves that are triggered by westerly wind bursts (WWB). From higher temporal resolution of reanalysis data, WWBs above a certain threshold are required to trigger a Kelvin wave. Kelvin waves are triggered in locations of positive Ocean Heat Content (OHC) anomalies. Intensity, longitudinal coverage and duration of a WWB, the strength of the OHC anomaly and gradient influence the amplitude of Kelvin waves as they propagate. Synoptic pattern analysis suggests that most WWBs are caused by cyclones with the combination of an active Madden-Julian Oscillation. The NorESM is able to reproduce many characteristics of observed WWBs, OHC anomalies and their relation to Kelvin waves. However, differences are noticeable for the distribution of synoptic patterns causing WWBs in the model. In future work, climate models can be used to disentangle causes and effects of EN for correlations identified here with the ultimate goal to advance our understanding of ENSO, its variability and future changes.
57

Studium genetické variability a diverzity u populací prasat plemene české bílé ušlechtilé

Černošková, Barbora January 2014 (has links)
The aim of this thesis was to analyze populations of pigs of breed Czech Large White and to evaluate their genetic variability and diversity. Eleven single-nucleotide polymorphisms (SNPs) were analyzed in porcine candidate genes. In total, 139 individuals from two populations of different status in breeding program were evaluated. Polymorphisms were genotyped by PCR-RFLP in loci: HMGCR, TCF7L2, MC4R, EDG4, HFABP, FTO, LEPR6, LEPR18, PDK4, PLINHin, PLINNIa. Population-genetic analysis was done in program POPGENE 1.31. All observed loci were polymorphic. The occurrence of rare allele T of locus EDG4 in population of breeding program was considered. Genetic diversity in population of commercial breed was higher than diversity of breeding population. All observed populations were in Hardy-Weinberg equation.
58

An analysis for the determination of the best measure of precipitation for the estimation of bankfull width

SHRESTHA, SURAJ 01 August 2015 (has links)
It has been demonstrated in past studies that drainage area (Ada) and mean annual precipitation depth (Pmean) are significant independent variables for predicting bankfull channel geometry. Bankfull width (Wbf), a particularly useful measure of bankfull channel geometry, is used in hydrology, fluvial geomorphology and stream ecology applications. Since precipitation depth does not generally have a normal distribution over a basin it is reasonable to question whether or not Pmean is the best measure of precipitation across a basin. That is, perhaps the median precipitation depth (P50) or the mean annual precipitation depth at the basin outlet (Poutlet) is more representative of precipitation in a basin. The objective of the study is to see if Pmean, P50, or Poutlet is a significantly better measure of precipitation in a watershed. Along with Ada, each of these precipitation measures was used to develop relationships for predicting Wbf for basins located across the continental U.S. Using several goodness-of-fit statistics i.e., coefficient of determination(R2), Standard error of estimates(SEE) and Akaike Information Criterion(∆AIC), the relationships were compared to determine which one had the greatest predictive strength. Estimates of Pmean, P50, and Poutlet were derived from a precipitation model developed by PRISM. Results from this study tentatively indicate that all three measures of precipitation depth yield models for predicting Wbf that have comparable goodness-of-fit statistics.
59

Variabilidade genética para o teor de óleo entre progênies autofecundadas de mamona (Ricinus cummunis L.) da cultivar guarani /

Myczkowski, Mirina Luiza, 1978- January 2003 (has links)
Orientador: Maurício Dutra Zanotto / Resumo: O presente trabalho teve como objetivo avaliar a variabilidade genética para teor de óleo entre progênies autofecundadas da cultivar de mamona Guarani. O material utilizado foi constituído de 135 progênies obtidas de plantas individuais, por meio de autofecundações artificiais, divididas em três experimentos e parcelas com 10m2. As avaliações foram realizadas em duas localidades, em Araçatuba - SP e em São Manuel - SP, na Fazenda Experimental São Manuel, da Faculdade de Ciências Agronômicas - UNESP/Botucatu. Foi avaliado o teor de óleo obtido por meio do método químico Soxhlet. Para cada localidade foram realizadas análises estatísticas segundo o delineamento de blocos ao acaso e também uma análise conjunta para os dois locais. Foram determinados os parâmetros genéticos, variância genética e coeficiente de herdabilidade. Os quadrados médios da interação de progênies por locais avaliadas na análise conjunta foram significativos a 5% de probabilidade pelo teste F em todos os experimentos, o que define a existência de comportamento diferencial de progênies em relação aos locais quanto ao teor de óleo. Os quadrados médios da análise de variância entre progênies dentro de locais apresentaram significância a 5% de probabilidade pelo teste F em todos os experimentos de Araçatuba, mostrando a existência de diferenças genéticas entre progênies, já nos experimentos de São Manuel os quadrados médios não foram significativos indicando assim ausência ou baixa variabilidade genética para teor de óleo. A média de teor de óleo, em São Manuel foi 43,22%, variando de 34,87% a 49,24%. Em Araçatuba, a média foi 43,59%, variando de 30,24% a 53,60%. A variância genética e o coeficiente de herdabilidade foram, respectivamente 0.32 e 0,10 para São Manuel e 4,87 e 0,44 para Araçatuba. Estes valores mostram a possibilidade de sucesso na seleção para teor de óleo nas condições de Araçatuba. / Abstract: The purpose of the research was to evaluate the genetic variability for oil content among lines of castor bean, cv. Guarani. Using artificial self- fertilizations, 135 lines were obtained from individual plants and tested in two locations in the state of São Paulo : Araçatuba and São Manuel, utilizing randomized block design with three replications and plots with 10m2. Oil content was determined by the Soxhlet chemical method. Individual and joint analysis of variance were made to estimate genetic parameters. The mean squares of the line x location interaction were significant by the F test with 5% of probability, that demonstrated the existence of differential behavior of lines due locations for oil content. The mean squares of the variance analysis among lines were significant by the F test with 5% of probability in Araçatuba, showing the existence of genetic differences among lines. However, in São Manuel, the mean squares were not significant, showing absence or low genetic variability for oil content. Average of line oil content, in São Manuel was 43.22% (from 34.87% to 49.24%). In Araçatuba the oil content mean was 43.59% (from 30.24% to 53.6%). Genetic variance and heritability coefficients were respectively 0.32 and 0.10 for São Manuel and 4.87 and 0.44 for Araçatuba. Those values show the possibility to improve the oil content by selection in Araçatuba conditions. / Mestre
60

Bootstrap Exploration of the Duration of Surface Electromyography Sampling in Relation to the Precision of Exposure Estimation

Fethke, Nathan B., Anton, Dan, Cavanaugh, Joseph E., Gerr, Fred, Cook, Thomas M. 01 January 2007 (has links)
Objectives: This study examined the effect of sampling duration, in units of work cycles, on the precision of estimates of exposure to forceful exertion obtained with surface electromyography (EMG). Methods: Recordings of the activity of the flexor digitorum superficialis, extensor digitorum, and upper trapezius muscles over 30 consecutive work cycles were obtained for a random sample of 25 manufacturing workers, each of whom was performing a unique production task representing a portion of the whole job. The mean root-meansquare amplitude and the 10th, 50th, and 90th percentiles of the distribution function of the amplitude probability were calculated for each cycle. Bootstrap analyses were used to examine the precision of the summary measures as the sampling duration increased incrementally from 1 to 30 work cycles. Precision was estimated by calculating the coefficient of variation (CV) of the bootstrap distributions at each sampling duration increment. Results: The average minimum sampling duration for a bootstrap distribution CV of 15% ranged from 2.0 (SD 1.5) cycles to 7.5 (SD 9.6) cycles, depending on muscle and summary measure. For a 5% CV, the average minimum sampling duration ranged from 11.9 (SD 9.0) to 20.9 (SD 10.5) cycles. Conclusions: The results suggest that sampling as few as three work cycles was sufficient to obtain a bootstrap distribution CV of 15% for some of the muscles and summary measures examined in this study. While limited to machine-paced, cyclic manufacturing work, these results will assist the development of exposure assessment strategies in future epidemiologic studies of physical risk factors and musculoskeletal disorders.

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