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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.
441

A design method for morphological filters

Lui, Guan-Liang 23 August 2010 (has links)
The purpose of Morphology is to capture features and attributes of image, such as boundaries and contours. It has been widely applied to computer vision, the analysis and processing of image and even industry examinations and medical image processing. The reason why the Morphology is widely applied is that we can use its simple structure elements to process images, and get up to our requirements. Therefore, it¡¦s become our primary study to find out those suitable structure elements. In this paper, we used the laws of judging the multiple mask relationship to find out filters which came up to the condition that we set, and also came up with an efficient way to find out filters that we want to get.
442

Phylogenetic reconstruction of the tussock moth tribe Nygmiini (Lepidoptera: Lymantriidae) based on morphological characters

Liao, Shih-ruei 24 August 2010 (has links)
The Nygmiini is a tussock moth tribe which is redominantly distributed in most regions of the Old World. It was established in order to accommodate several genera that were previously associated with the polyphyletic genus Euproctis Hübner, 1819, which was erected upon the western European Euproctis chrysorrhoea (Linnaeus, 1758)(=Phalaena chrysorrhoea) and has included 682 valid specific names since the early 19th century. The caterpillars of Nygmiini are fairly polyphagous on various woody plant families, and thus many of them are considered as pests with significant importance. They are also known for having importance in public health due to the strong allergic reaction caused by the urticating setae. Although the tribe Nygmiini as well as the core genus Euproctis has such importance in various aspects, it¡¦s monophyletic status and phylogenetic relationships have never been tested using modern phylogenetic methods. I therefore sampled 175 lymantriid species representing most of the potential members of Nygmiini plus one arctiid species as the outgroup taxon to reconstruct the phylogeny of this tribe based on morphological characters from all development stages. The results suggest that the tribe Orgyiini forms a monophyletic clade with the Nygmiini, while neither the Nygmiini sensu Holloway nor the genus Euproctis sensu auctorum is monophyletic, and thus the taxonomic boundary of the tribe should be redefined in accordance to the hypothesis proposed by the present study. On the other hand, larval characters become the major source of the synapomorphies of the Nygmiini. The adult wing patterns which are used to taxonomic identification, however, are highly convergent among genera and thus these characters are not supposed to be informative in systematic research.
443

The study of electrospun nanofibers and the application of electrospinning in engineering education

Call, Christopher Calvin 15 May 2009 (has links)
During electrospinning, a polymer solution becomes an electrically driven jet as it travels to a grounded plate. While the behavior of pressure-driven liquid jets has been extensively studied in fluid mechanics, none of the characteristics of fluid jet break up have been applied to electrospinning. Calculating Weber number can describe what type of breakup occurs as the polymer jet travels to the plate, which could also predict the surface morphology of electrospun fibers. Polyethylene oxide (PEO) solution was electrospun at different voltages to test whether the morphology of the electrospun fibers can be predicted through calculating Weber number. While the continuing research of electrospinning is important, the subject of electrospinning can be used as a course to teach students engineering principals over a semester. Due to the vast interdisciplinary subjects associated with electrospinning, teaching the subject as a course will give students an understanding of critical thinking skills as well as first hand accounts of research. Four weight percent PEO solution was electrospun at a range of testing parameters until the desired results were achieved, beaded or non-beaded fibers. The Weber numbers were calculated and compared to the electrospun material created. Analyzing the surface morphology revealed a beaded to non-beaded trend in nanofibers corresponding to high-to-low Weber numbers. The same trend continued for higher weight percents of PEO solutions electrospun. The course will have many learning objectives the instructor is expected to have the students achieve, building the objectives to help the students become better researchers and to learn the material. Splitting the course into three five week sections will help students understand each component of the electrospinning process, as well as fundamental engineering equations and theories. The students at the end of the semester should be able to recreate the electrospinning process on their own and create nanofibers of varying sizes. The course should also excite students about pursuing more advanced degrees in scientific fields.
444

An ecophysiological framework for the morphological evolution of bluegill sunfish

Papadopoulos, Anthony 15 May 2009 (has links)
Body shape affects the capacity and efficiency of swimming in fishes, and places constraints on foraging and reproductive performance. Hence, fitness components, such as aerobic swimming capacity and efficiency, can be determined from analysis of swimming energetics using active respirometry. In particular, body shape adaptations, such as streamlining, aim at reducing hydrodynamic drag (resistance), thereby increasing swimming efficiency in the presence of water flow, which is a principal contributor to resistance for fish inhabiting rivers. For two populations of bluegill sunfish, one from the Brazos River and the other from Moelman’s Slough (a Brazos River oxbow lake), the metabolic transport rate (MTR) was determined to evaluate differences in swimming efficiency. The standard cost of swimming (SCOS) was also determined to evaluate differences in swimming capacity, which represents the overall capacity of the skeletal muscles to generate mechanical power to overcome hydrodynamic resistance. The MTR and the SCOS describe holistic swimming performance, where the MTR specifies the hydrodynamic response due to swimming, and the SCOS specifies the physiologic response due to swimming. The differences in swimming performance are mainly attributed to factors affecting hydrodynamic resistance and could be predicted by morphology; because body shape, like water flow, is also a principal contributor to resistance. Multivariate body shape, from generalized Procrustes analysis, was used to assess the influence of multiple shape traits on swimming costs. This measure of shape related to swimming performance using partial least-squares analysis showed the two bluegill populations to be significantly different. The results were as follows: the shallow-bodied condition in bluegills was highly correlated with efficient swimming and low swimming capacities; whereas, deep-bodied bluegills were highly correlated with inefficient swimming and high swimming capacities. This is an empirical case of divergent natural selection. For convergence, however, the position of the caudal peduncle is consistent with optimal swimming speed (Um), which depends on standard metabolic rate (SMR), or metabolic maintenance. Bluegills with erect caudal peduncles have a high range of swimming speeds without suffering much cost of swimming ability compared to bluegills with prone caudal peduncles. The adaptive physiological response to high Um is due to a low SCOS because swimming efficiency is low and metabolic maintenance is high. In other words, bluegills that are inefficient swimmers and require a high energy intake cannot survive unless they gain the ability to increase their foraging capacity by thrust or metabolic power reduction. This is perhaps one of the most remarkable adaptive physiological responses due to the joint effects of shape and SMR.
445

Improving spelling ability among speakers of African American vernacular English: an intervention based on phonological, morphological, and orthographic principles

Pittman, Ramona Trinette 15 May 2009 (has links)
Given the importance of the role of spelling in literacy, it is important to have knowledge of the linguistic features that allow students to be successful spellers. Having phonological, morphological, and orthographic knowledge is essentially important to spell conventionally. In the United States, the standard language is Academic English (AE). African American Vernacular English (AAVE) is considered a deviation from AE, with its own sound system. AAVE is the most widely used form of dialect in the United States. Many students who speak AAVE may have difficulties in producing the correct spelling of AE words. The overall purpose of this study was to provide sixth-grade students, who are speakers of AAVE, with an eight-week intervention in the principles of phonology, morphology, and orthography that would assist them in improving their spelling performance. Students had similar scores on all spelling and dialect pretest measures before the intervention began. The research design was a pretest/posttest/posttest design using waitlist- control. This study included 142 students divided into 14 class sections taught by two teachers. The two teachers provided the intervention to the students. The experimental group consisted of seven classes, and the control group consisted of seven classes. After the first implementation of the intervention, the study was replicated with the control group of students. MANOVA was utilized to determine the effect of the intervention. The intervention produced large effects for the students who received the spelling instruction. The results from the criterion-referenced spelling assessments and a sentence writing task revealed that students who received explicit instruction from the intervention made gains in their spelling performance from pretest/posttest 1/posttest 2 and maintained these gains after being tested eight weeks later. Practical and theoretical recommendations are provided for teachers and researchers. Suggested recommendations include: providing teacher training that will enable teachers to be more linguistically aware of AAVE and its features, making students aware of the difference in the AAVE and the AE sound system, and conducting more research-based studies that will assist speakers of AAVE in literacy and spelling.
446

Algorithms and Software Tools for Extracting Coastal Morphological Information from Airborne LiDAR Data

Gao, Yige 2009 May 1900 (has links)
With the ever increasing population and economic activities in coastal areas, coastal hazards have become a major concern for coastal management. The fundamental requirement of coastal planning and management is the scientific knowledge about coastal forms and processes. This research aims at developing algorithms for automatically extracting coastal morphological information from LiDAR data. The primary methods developed by this research include automated algorithms for beach profile feature extraction and change analysis, and an object-based approach for spatial pattern analysis of coastal morphologic and volumetric change. Automated algorithms are developed for cross-shore profile feature extraction and change analysis. Important features of the beach profile such as dune crest, dune toe, and beach berm crest are extracted automatically by using a scale-space approach and by incorporating contextual information. The attributes of important feature points and segments are derived to characterize the morphologic properties of each beach profile. Beach profiles from different time periods can be compared for morphologic and volumetric change analysis. An object-oriented approach for volumetric change analysis is developed to identify and delineate individual elevation change patches as discrete objects. A set of two-dimensional and three-dimensional attributes are derived to characterize the objects, which includes planimetric attributes, shape attributes, surface attributes, volumetric attributes, and summary attributes. Both algorithms are implemented as ArcGIS extension modules to perform the feature extraction and attribute derivation for coastal morphological change analysis. To demonstrate the utility and effectiveness of algorithms, the cross-shore profile change analysis method and software tool are applied to a case study area located at southern Monterey Bay, California, and the coastal morphology change analysis method and software tool are applied to a case study area located on Assateague Island, Maryland. The automated algorithms facilitate the efficient beach profile feature analysis over large geographical area and support the analysis of the spatial variations of beach profile changes along the shoreline. The explicit object representation of elevation change patches makes it easy to localize erosion hot spots, to classify the elevation changes caused by various mechanisms, and to analyze spatial pattern of morphologic and volumetric changes.
447

The Effects of Probiotic and Eimeria on Gut Morphology and Humoral Immunity in Broilers

Horrocks, Sadie Lyn 2010 December 1900 (has links)
Coccidiosis has a negative economic impact on the commercial poultry industry, and probiotics are beneficial bacteria that aid in maintaining healthy gut microflora. We hypothesized that probiotic administration would positively affect gut morphology and increase IgG secretion during an Eimeria challenge, which was evaluated by measuring total chicken IgG and gut morphology (villus height, villus width, villus surface area, crypt depth, villus height to crypt depth ratio and lamina propria thickness). On day-of-hatch, broilers were placed into floor pens with 50 percent pine shavings and 50 percent used litter. The broilers were exposed to Eimeria oocysts via the feed on day 14 and challenged on day 36. On days 6, 22, 36, and 43, tissue samples from the intestine were collected for morphological evaluation, and blood samples were taken to quantify chicken IgG from serum. Data were measured using a factorial ANOVA and main effect means were deemed significant at P ≤ 0.05. In cases where significant interactions were observed, data was subjected to a one-way ANOVA. All means were separated using a Duncan’s Multiple Range Test. On day 6 in the duodenum, a significant interaction was observed regarding vaccination and probiotic administration (Coccivac®-B, Intervet/Schlering-Plough Animal Health/Merck and Co., Inc., Whitehouse Station, NJ). Villus height to crypt depth ratio decreased in ionophore treated birds compared to control birds in the duodenum and lower ileum on day 6, 36, and 43. Villus crypt depth in vaccinated birds decreased in the duodenum after the challenge. On day 43, the ionophore treated birds had less villus height and surface area compared to control and vaccinated birds, while lamina propria thickness increased in the duodenum, and non probiotic birds had longer villi than probiotic birds. On day 22, vaccinated birds had significantly increased chicken IgG levels compared to the control and ionophore birds, and the non probiotic birds had significantly increased IgG secretion compared to probiotic fed birds. On day 36, the ionophore birds had significantly increased levels of IgG compared to the control birds, which could also support that the ionophore delayed exposure to the parasite. These results suggest that gut morphology and humoral immunity are affected by probiotic administration, coccidiosis vaccination, ionophore application and Eimeria challenge. Both the day 43 morphology results and day 36 chicken IgG results for the ionophore treated birds demonstrates that ionophore administration delays exposure of the avian gut to invasive coccidia. More research is necessary to evaluate how probiotics influence coccidiosis vaccination and humoral immunity, so that probiotics may be used to improve the effectiveness of coccidiosis vaccination and to evaluate if probiotics aid in ameliorating the effects of an Eimeria infection.
448

The systematic studies of morphology, molecular phylogeography, and reproductive biology within Cobitis sinensis complex in Taiwan and east southern China

Chin-Wen, Wang 31 January 2005 (has links)
Chinese spined loach, Cobitis sinensis complex are primary benthic fishwater fishes with inhabiting on the substratum of small pebbles or coarse sand in mountain streams. In Taiwan, C. sinensis complex has been recorded from most drainages of western side of the Central Mountain Ridge including from Ilan, Taipei, even to Pingtung County. In Taiwan, all Cobitis populations have been considered as C. sinensis which types assigned from the Szechuan province, Yangtsi River basin by Sauvage and Dabry de Thiersant (1874). Due to very limited diagnostic morphological features can be detected and studied in detail, it¡¦s more important for reconstructing the molecular phylogenetic relationship by DNA sequences. We also study in the reproductive biology by the samples in Kao-ping River, and to compare the realationship by the samples in Tan-shuei River. By morphological analysis and mtDNA D-loop sequences clustering, we can recognize the C. sinensis complex of Taiwan and southern China into three group: (1) northern and middle Taiwan (NT) (as typical C. sinensis); (2) three River basins in southern Taiwan (ST) (C. sp1); (3) other samples from the Fujian provinces (ST) (C. sp2). They can be distinguished by very distinct differentiations of the scale of Canestrini. The type of NJ tree and MP tree are the overall same topology, mean that the trees of result are the stable phylogenetic tree of the whole C. sinensis complex. By the result of reproductive biological study, GSI index rise in May and drop off in September, the high peak time is close to five months. The increasing tendency of GSI is later than the temperature rising, but earlier than the rainfall begin in July. They share the similar trend among the comparison of the mature of gonad¡Bthe distribution of egg diameter and GSI index.
449

Effects of light intensity on the morphology and physiology of the soft coral (Pachyclavularia violacea ).

Tsai, Chi-Han 03 March 2005 (has links)
The present study was undertaken to determine the effects of varying light intensities on the morphology and physiology of the soft coral Pachyclavularia violacea. The soft corals P. violacea were treated by LED light and the illumination ranged from 50 to 200 £gmol photon m-2 s-1, i.e. high light (200 £gmol photon m-2 s-1), medium light (140 £gmol photon m-2 s-1), medium-low light (100 £gmol photon m-2 s-1 and low light (50 £gmol photon m-2 s-1). The theca length, the density of zooxanthellae and the concentrations of chlorophyll a and proteins were measured to evaluate the response of P. violacea to different light intensities. A significant longer theca length was found in the group of medium-low light (5¡V 9mm) than the groups of high and low light intensities (1-2mm) (p<0.001). And, the theca length in the groups of medium and medium-low was more close to their source population. Over the 6-month experimental periods, the densities of zooxanthellae in the groups of medium and medium-low were in the range of 1.5 ~3.8 x 105 (N/mg) which were significantly higher than other groups (p<0.01). The concentrations of chlorophyll a in the low light group were 0.5~ 2.0 (ng/mg) during the experimental periods which were significantly higher than other groups (p<0.05). In the fifth and sixth months, the concentrations of chlorophyll a per zooxanthellae in the group of medium-low were in the range of 0.4~5.8 Chl. a ¡Ñ 10-5 (ng/zoox.) which were significantly higher than other groups (p<0.01). The protein content in the group of low light was significantly lower than other groups in the fifth month. And, the protein contents were decreased significantly in all groups in the sixth month. Based on the results, it is concluded that theca length and the density of zooxanthellae were sensitive responses to light adaptation. The light intensity about 100 £gmol photon m-2 s-1 might be an appropriate range to culture the soft coral P. violacea because the theca length in the group was close to its source population.
450

Deposition of AlN Thin Films by Coherent Magnetron Sputtering

Lee, Feng-Zhi 22 June 2005 (has links)
Polycrystalline AlN thin films were reactively deposited onto Al layers on negatively biased glass and Si substrates at temperatures < 80 oC by coherent magnetron sputtering. The target-to-substrate distance is 17 cm. The microstructures and morphology of the films grown at different bias voltages on the substrates were investigated. Typical thickness of the deposited film is 600 nm. The films were amorphous when no bias was applied to the substrates. Diffraction peak of AlN (002) direction was observed at bias voltages of -180 and -210 V. At a bias voltage of -210 V, the (002) granular crystal with the maximum diameter of 80 nm was obtained. In addition to the AlN (002) direction, AlN (100) direction was observed when the bias voltage was increased to -240 and -270 V. The peak of (002) plane vanished at a bias voltage of -320 V. Moreover, the deposited AlN films have specular reflectance owning to the large target-to-substrate distance. The maximum roughness of the films was 47.2¡Ó5.0 nm at a bias voltage of -210 V. The hardness and microstructure of aluminum nitride (AlN) thin films prepared by long-distance magnetron sputtering at room temperature has been investigated. The hardness and microstructure of the films were found to vary greatly with different substrate biases. At a bias voltage of ¡V210 V, the (002) polycrystalline AlN with the maximum hardness of 17.5 GPa was observed. The water droplet contact angle under this bias condition is larger than 90¢X indicating that hydrophobicity can be obtained at the film surface. In addition, hardness of (002) AlN films prepared by sputtering of AlN target at room temperature and by reactive sputtering of Al target at 400¢XC were discussed and compared with that of AlN films prepared by long-distance reactive sputtering.

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