To see the other types of publications on this topic, follow the link: Morphological features of ECG.
Dissertations / Theses on the topic 'Morphological features of ECG'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Morphological features of ECG.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Lei, Wai Kei. "An exploration of intelligent ECG interpretation using morphological feature characterization and support vector machine classification." Thesis, University of Macau, 2007. http://umaclib3.umac.mo/record=b1692866.
Full text
2
Gawde, Purva R. "INTEGRATED ANALYSIS OF TEMPORAL AND MORPHOLOGICAL FEATURES USING MACHINE LEARNING TECHNIQUES FOR REAL TIME DIAGNOSIS OF ARRHYTHMIA AND IRREGULAR BEATS." Kent State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=kent1544106866041632.
Full text
3
Tichý, Pavel. "Detekce ischemie v EKG záznamech." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-220839.
Full textAbstract:
This paper describes the manifestations of ischemia in the ECG signals and summarizes some methods allowing automatic detection of ischemia. Morphological features were then calculated from ECG signals available from UBMI and statistically evaluated to select features appropriate for further automatic classification. Multilayer feedforward neural network was used for classification of heart beats. The neural network was designed in Matlab. Classification performance up to 99.9% was obtained on available dataset.
4
Newell, John T. "Pixel classification by morphological granulometric features /." Online version of thesis, 1991. http://hdl.handle.net/1850/11210.
Full text
5
Noyer, Robert Rolf. "Features, positions and affixes in autonomous morphological structure." Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/12895.
Full text
6
Bozed, Kenz Amhmed. "Detection of facial expressions based on time dependent morphological features." Thesis, University of Bedfordshire, 2011. http://hdl.handle.net/10547/145618.
Full textAbstract:
Facial expression detection by a machine is a valuable topic for Human Computer Interaction and has been a study issue in the behavioural science for some time. Recently, significant progress has been achieved in machine analysis of facial expressions but there are still some interestes to study the area in order to extend its applications. This work investigates the theoretical concepts behind facial expressions and leads to the proposal of new algorithms in face detection and facial feature localisation, design and construction of a prototype system to test these algorithms. The overall goals and motivation of this work is to introduce vision based techniques able to detect and recognise the facial expressions. In this context, a facial expression prototype system is developed that accomplishes facial segmentation (i.e. face detection, facial features localisation), facial features extraction and features classification. To detect a face, a new simplified algorithm is developed to detect and locate its presence from the fackground by exploiting skin colour properties which are then used to distinguish between face and non-face regions. This allows facial parts to be extracted from a face using elliptical and box regions whose geometrical relationships are then utilised to determine the positions of the eyes and mouth through morphological operations. The mean and standard deviations of segmented facial parts are then computed and used as features for the face. For images belonging to the same class, thses features are applied to the K-mean algorithm to compute the controid point of each class expression. This is repeated for images in the same expression class. The Euclidean distance is computed between each feature point and its cluster centre in the same expression class. This determines how close a facial expression is to a particular class and can be used as observation vectors for a Hidden Markov Model (HMM) classifier. Thus, an HMM is built to evaluate an expression of a subject as belonging to one of the six expression classes, which are Joy, Anger, Surprise, Sadness, Fear and Disgust by an HMM using distance features. To evaluate the proposed classifier, experiments are conducted on new subjects using 100 video clips that contained a mixture of expressions. The average successful detection rate of 95.6% is measured from a total of 9142 frames contained in the video clips. The proposed prototype system processes facial features parts and presents improved results of facial expressions detection rather than using whole facial features as proposed by previous authors. This work has resulted in four contributions: the Ellipse Box Face Detection Algorithm (EBFDA), Facial Features Distance Algorithm (FFDA), Facial features extraction process, and Facial features classification. These were tested and verified using the prototype system.
7
Han, Richard I.-Ming. "Morphological, cellular and proteomic features of canine myxomatous mitral valve disease." Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/4286.
Full textAbstract:
Myxomatous mitral valve degeneration (MMVD) is the single most common cardiac disease of the dog, and is analogous to Mitral Valve Prolapse in humans. Very little is known about the aetiopathogenesis of this disease or the changes in valvular interstitial cell populations in diseased valves. The aim of this study was to identify morphological, cellular and molecular changes associated with MMVD. Mitral valve leaflets from both normal and varying grades (Whitney’s 1-4) of diseased dogs were subject to image analysis, immunophenotyping, proteomics and RT-PCR. Image analysis - leaflet thickening due to accumulation of glycosaminoglycan was significant in this disease. MMVD is associated with loss of connective tissue, reduction in cell numbers but no change in cell shape in the overtly myxomatous area. Near the surface, increase in valvular interstitial cells (VIC) towards the damaged endothelium in concert with destruction of collagen and building up of ground substance was manifested during the disease process. Immunophenotyping - activated myofibroblasts were increased and fibroblast-like VICs were reduced without any change in desmin and myosin expression in MMVD compared to clinical normal dogs. In addition, other cell types like macrophage, adipocyte, chondrocyte, mast cell, and stem cell were identified and their possible role in MMVD is discussed. Proteomics - a protein expression profile was established, with 64 proteins being positively identified from dog’s mitral valve using 1-D SDS PAGE LC/MS. Amongst them 44 proteins were differentially expressed comparing normal and severely diseased. Two actin binding proteins, tropomyosin alpha and myosin light chain-2 were found to be differentially expressed in the normal but down regulated in the diseased. RT-PCR was used to assess the expression of 8 genes of interest. Their expression was compared with 3 different housekeeping genes.
8
De, Klerk Willouw. "A study of morphological, immunohistochemical and histochemical features of ampullary carcinomas." Master's thesis, University of Cape Town, 2005. http://hdl.handle.net/11427/3075.
Full textAbstract:
Includes bibliographical references (leaves 66-75).The aim of the first study was to examine clinical, histopathological and immunohistochemical features of ampullary carcinomas and to determine whether any of these features had significant prognostiC value. The immunohistochemical panel was selected after a literature review and included p53, Ki-67, MUC1, MUC1core, MUC2 and CA 19.9. The data was analyzed by multivariate analysis.
9
Di, Fusco Greta. "A Reliable Downscaling of ECG Signals for the Detection of T wave Heterogeneity Features." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016.
Find full textAbstract:
In cardiovascular disease the definition and the detection of the ECG parameters related to repolarization dynamics in post MI patients is still a crucial unmet need. In addition, the use of a 3D sensor in the implantable medical devices would be a crucial mean in the assessment or prediction of Heart Failure status, but the inclusion of such feature is limited by hardware and firmware constraints.
The aim of this thesis is the definition of a reliable surrogate of the 500 Hz ECG signal to reach the aforementioned objective. To evaluate the worsening of reliability due to sampling frequency reduction on delineation performance, the signals have been consecutively down sampled by a factor 2, 4, 8 thus obtaining the ECG signals sampled at 250, 125 and 62.5 Hz, respectively. The final goal is the feasibility assessment of the detection of the fiducial points in order to translate those parameters into meaningful clinical parameter for Heart Failure prediction, such as T waves intervals heterogeneity and variability of areas under T waves.
An experimental setting for data collection on healthy volunteers has been set up at the Bakken Research Center in Maastricht. A 16 – channel ambulatory system, provided by TMSI, has recorded the standard 12 – Leads ECG, two 3D accelerometers and a respiration sensor. The collection platform has been set up by the TMSI property software Polybench, the data analysis of such signals has been performed with Matlab.
The main results of this study show that the 125 Hz sampling rate has demonstrated to be a good candidate for a reliable detection of fiducial points. T wave intervals proved to be consistently stable, even at 62.5 Hz. Further studies would be needed to provide a better comparison between sampling at 250 Hz and 125 Hz for areas under the T waves.
10
Abu, Dalou Ahmad Y. "The validity of morphological features and osteological markers in reconstructing habitual activities." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/4877.
Full textAbstract:
Thesis (Ph.D.)--University of Missouri-Columbia, 2007.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (July 17, 2008) Includes bibliographical references.
11
Chamani, Alireza. "Development of computational image processing algorithms for detecting morphological features of melanoma." Thesis, University of Maryland, Baltimore County, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1583869.
Full textAbstract:
This thesis research is focused on advancing image processing techniques and algorithms used for detecting skin melanoma. We have modified previous image processing approaches and developed computational algorithms for quantifying morphological features of a mole image. Applying the algorithms to 20 mole images downloaded from educational websites, we have identified three cut-off ratios to distinguish melanoma images from benign mole images. More specifically, the higher the boundary irregularity ratio, and/or the asymmetry ratio, and/or the color variation ratio, the high chance the mole is melanoma leading. The irregularity ratio cutoff is identified as 1.96, suggesting 96% more circumference length than that of a circle with the same area. One finds that the cut-off ratio for assessing asymmetry of the mole image is 0.109, representing the degree of asymmetry as approximately 11% to place a mole image into the melanoma group. Evaluation of the color variation of the moles leads to a cut-off ratio of the color variation as 0.334. Statistical analyses have been performed to determine the confidence of cut-off ratios, varying from 63% to 81%, for placing a mole image into its correct groups. The algorithms have also been implemented to assess "changes" of mole images over time observed by a dermatologist. Using a ±14% as the definition of changes, the algorithm identifies 9 of the 10 mole images as changed over time. Among the irregularity, asymmetry, color variation, and size ratios, 5 out of the 9 moles have shown changes in one ratio, 2 out the 9 moles have experience changes in two ratios, 1 mole has shown changes in three ratios, and only 1 mole shows changes in all four ratios. The computational results are consistent with the general observations that human eyes are sensitive to size changes and color variation changes, and may not be very good to distinguish changes in border irregularity and asymmetry. The developed algorithms can be helpful to assist a physician in evaluating subtle changes of mole images that may not be very sensitive to the eyes.
12
Murphy, Liam. "Morphological and Physiological Features of Selected Acanthamoeba Strains: Clues to Opportunistic Pathogenicity." NSUWorks, 2009. http://nsuworks.nova.edu/occ_stuetd/230.
Full textAbstract:
Acanthamoeba are common in all environments and are the cause of Acanthamoeba keratitis. Acanthamoeba keratitis is a sight threatening infection of the cornea commonly found in association with contact lens wear. Acanthamoeba isolates tested grew at temperatures up to 35°C. They were also shown to be capable of growth at low oxygen conditions. Comparison between known pathogenic isolates and environmental isolates showed no clear difference in ability to grow in these conditions. Five isolates, three pathogenic, NSU05023, NSU05012, and NSU06001; and two environmental ones BP and MS26 grew faster to 400 trophozoites in low oxygen conditions than in ambient air. This ability would allow the isolates to grow between the contact lens and the cornea. Five contact lens multi-purpose solutions (Clear Care®, Opti-Free®, Complete®, Renu®, and Aquify®) were tested against four isolates; two pathogenic isolates NSU06004 and P120 and two environmental isolates HK17P191 and FLA22. Results showed that the hydrogen peroxide solution (Clear Care®) was more effective against all strains at 78.75% and the remaining four MPS solutions were below 35%. Acanthamoeba are very common in all environments and are capable of infecting the eye. The currently available contact lens disinfecting solutions are not very effective in preventing Acanthamoeba growth.
13
Scharinger, Mathias. "The representation of vocalic features in vowel alternations phonological, morphological and computational aspects /." [S.l. : s.n.], 2006. http://nbn-resolving.de/urn:nbn:de:bsz:352-opus-24341.
Full text
14
Benson-Goldberg, Sofia. "Spelling of Derivationally Complex Words: The Role of Phonological, Orthographic, and Morphological Features." Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5182.
Full textAbstract:
Spelling ability is not static; rather, as children age, learning how to encode morphophonologically complex words in conventional ways is motivated by the increasingly complex demands imposed by academic experiences with morphologically complex words. Success requires ongoing integration of phonological (P), orthographic (O) and morphological (M) knowledge. However, current research on the development and assessment of spelling has not sufficiently accounted for the way word features and participant characteristics interact with students' POM knowledge in the spelling of derived words. This study used a linear mixed effects regression approach to provide new insights about how both word characteristics and students' linguistic knowledge affected the application of POM from grades 3-7 in the spelling of derived forms.
Spelling data (WIAT-II) were taken from a larger longitudinal study focused on reading development (Garcia et. al., 2010). Eleven words from the WIAT-II with derivational morphology (which included one inflected form with a derived homophone possibility) were analyzed first with the Phonological Orthographic Morphological Analysis of Spelling (POMAS; an unconstrained scoring system) in order to identify linguistic feature errors within misspellings. Next, misspellings were quantified with the POMplexity metric to evaluate the individual and combined influences of phonology (P), orthography (O), and morphology (M) to derivational misspellings over time.
A linear mixed effects regression approach evaluated the impact of item-level characteristics (derivational frequency and shifts), participant characteristics (rime, spelling choice and morphological awareness task scores), and time (grade level) on POMplexity scores. Results indicated item-level characteristics, participant characteristics and time significantly predicted variation in P, O, M, and total POMplexity scores. Frequency had a significant impact on scores, with high frequency words resulting in lower POMplexity scores than low frequency words and these effects were most obvious in grades 3 and 4. Slope differences between words suggested that low frequency misspellings resolve more rapidly than high frequency words.
Derivational shift was shown to have a significant interaction with time for O, M and Total scores, but not P scores. In all cases, the slopes for derived words with no shift improved more quickly than shift categories. Finally, performance on measures on the measures of linguistic skill correlated to improved scores for the related POMplexity code.
These results strongly suggest that the developmental course of learning to spell derivations is not a linear accumulation of POM knowledge, but instead is a recursive process with both general and word-specific knowledge affecting how an individual student produces a derivational spelling at any given point in time. Contributions of word characteristics, such as frequency and number/type of derivational shift, suggest that morphemic features challenge encoding; that is, increased complexity taxes the system's ability to represent both sound and meaning orthographically. Educational and clinical implications will be described.
15
Reem, Adel Roufail. "The effect of stirred mill operation on particles breakage mechanism and their morphological features." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/38190.
Full textAbstract:
Stirred milling is a grinding tool that is used extensively for mineral liberation, in order to achieve successful downstream processing such as flotation or leaching. The focus of this research is to understand the effect of different operating parameters on particle breakage mechanism. Operating parameters could be summarized as stress intensity on the particles which are varied by changing the mill’s agitator speed, and different ground material properties such as extreme hard/low density minerals like quartz versus soft/high density minerals like galena. Grinding performance is assessed by analysing particle size reduction and energy consumption. Breakage mechanism is evaluated using the state of the art morphological analysis and liberation. Finally, theoretical evaluation of particles flow, types of forces and energy distribution across the mill are investigated using Discrete Element Modelling (DEM).
It is observed that breakage mechanisms are affected by the type of mineral and stress intensities (agitator speed) in the mill. For example, galena, the soft/high density mineral, reaches its grinding limit very fast at high agitator speed and specific energy consumption increases exponentially with the increase of the agitator speed. On the other hand, for quartz, the hard/low density mineral, the breakage rate is very slow at low agitator speed and the specific energy consumption increases linearly with the increase of the agitator speed. Fracture mechanism of the particles is also a function of the agitator speed and type of mineral. At high agitator speed, galena fractures mostly along the grain boundaries, whereas quartz breaks across the grains, which is abrasion. The morphology observation is confirmed by the DEM model, which conveyed that at higher agitator speed, the normal forces were higher than tangential forces on the galena particles compared to the ceramic grinding media particles.
The core of this research is the morphology analysis, which is a novel approach to studying particle breakage mechanisms. More work is recommended in the field of morphology with other types of minerals to confirm the findings of this research. 3D liberation analysis was introduced in this research; a correlation to the conventional liberation methodology would be a major addition to the industry.
16
Marti, Puig Patricia <1985>. "Genetic and Morphological Features of Patella Caerulea and Patella Rustica across Mediterranean Marine Protected Areas." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amsdottorato.unibo.it/7570/.
Full textAbstract:
Marine Protected Areas (MPAs) were initially created to protect the living, non-living, cultural and/or historical values from human activities. The Convention on Biological Diversity (CBD; Earth Summit in Rio de Janeiro on 5 June 1992) has set a target of protecting 10% of the coastal and marine areas by 2020, which has led to a rapid increase in the creation of MPAs worldwide. Within this context, there is a growing concern regarding the number of efficient MPAs. One of the main issues is that biological or ecological features of marine species as well as ecosystem processes are not taken into account in MPA design. Deciding criteria for species management requires considerable information collected from a number of sources, including morphometric data, genetic data and distributional data. Morphometric tools are useful to study species taxonomy, or to provide information about the morphological variability, size and growth of the species, which is essential for MPA monitoring. Genetic tools can be use to resolve species taxonomy or population structure, allowing to estimate genetic diversity and connectivity of populations at different temporal and spatial scales. Both morphometric and genetic data used in combination provide a powerful tool that should be considered in MPA assessment. However, the accurate interpretation and the integration of this information into marine spatial planning is specially challenging. The aim of this PhD thesis was to develop a protocol for monitoring Marine Protected Areas by studying the morphology and genetics of two closely limpet species (Patella rustica and Patella caerulea) across MPAs in the Western Mediterranean sea. Overall, the results of this thesis provides support the inclusion of the morphological and genetic tools into management plans, and in the guidelines for the monitoring to improve and/or maintain MPA health and effectiveness.
17
Wang, Tonghe. "Identifying Base Noun Phrases by Means of Recurrent Neural Networks : Using Morphological and Dependency Features." Thesis, Uppsala universitet, Institutionen för lingvistik och filologi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-412778.
Full textAbstract:
Noun phrases convey key information in communication and are of interest in NLP tasks. A base NP is defined as the headword and left-hand side modifiers of a noun phrase. In this thesis, we identify base NPs in Universal Dependencies treebanks in English and French using an RNN architecture.The data of this thesis consist of three multi-layered treebanks in which each sentence is annotated in both constituency and dependency formalisms. To build our training data, we find base NPs in the constituency layers and project them onto the dependency layer by labeling corresponding tokens. For input features, we devised 18 configurations of features available in UD annotation. We train RNN models with LSTM and GRU cells with different numbers of epochs on these configurations of features.Tested on monolingual and bilingual test sets, our models delivered satisfactory token-based F1 scores (92.70% on English, 94.87% on French, 94.29% on bilingual test set). The most predicative configuration of features is found out to be pos_dep_parent_child_morph, which covers 1) dependency relations between the current token, its syntactic head, its leftmost and rightmost syntactic dependents; 2) PoS tags of these tokens; and 3) morphological features of the current token.
18
Omran, Abir. "Improving ligand-based modelling by combining various features." Thesis, Uppsala universitet, Institutionen för farmaceutisk biovetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-448769.
Full textAbstract:
Background: In drug discovery morphological profiles can be used to identify and establish a drug's biological activity or mechanism of action. Quantitative structure-activity relationship (QSAR) is an approach that uses the chemical structures to predict properties e.g., biological activity. Support Vector Machine (SVM) is a machine learning algorithm that can be used for classification. Confidence measures as conformal predictions can be implemented on top of machine learning algorithms. There are several methods that can be applied to improve a model’s predictive performance. Aim: The aim in this project is to evaluate if ligand-based modelling can be improved by combining features from chemical structures, target predictions and morphological profiles. Method: The project was divided into three experiments. In experiment 1 five bioassay datasets were used. In experiment 2 and 3 a cell painting dataset was used that contained morphological profiles from three different classes of kinase inhibitors, and the classes were used as endpoints. Support vector machine, liblinear models were built in all three experiments. A significant level of 0.2 was set to calculate the efficiency. The mean observed fuzziness and efficiency were used as measurements to evaluate the model performance. Results: Similar trends were observed for all datasets in experiment 1. Signatures+CDK13+TP which is the most complex model obtained the lowest mean observed fuzziness in four out of five times. With a confidence level of 0.8, TP+Signatures obtained the highest efficiency. Signatures+Morphological Profiles+TP obtained the lowest mean observed fuzziness in experiment 2 and 3. Signatures obtained the highest correct single label predictions with a confidence of 80%. Discussion: Less correct single label predictions were observed for the active class in comparison to the inactive class. This could have been due to them being harder to predict. The morphological profiles did not contribute with an improvement to the models predictive performance compared to Signatures. This could be due to the lack of information obtained from the dataset. Conclusion: A combination of features from chemical structures and target predictions improved ligand-based modelling compared to models only built on one of the features. The combination of features from chemical structures and morphological profiles did not improve the ligand-based models, compared to the model only built on chemical structures. By adding features from target predictions to a model built with features from chemical structures and morphological profiles a decrease in mean observed fuzziness was obtained.
19
Crole, Martina Rachel. "A gross anatomical and histological study of the oropharynx and proximal oesophagus of the emu (Dromaius novaehollandiae)." Diss., University of Pretoria, 2009. http://hdl.handle.net/2263/24625.
Full textAbstract:
This study describes the gross anatomical, histological and surface morphological features of the oropharynx and proximal oesophagus of the emu in order to address the scarcity of information on this region in this commercially important bird. Heads obtained from birds at slaughter (and a younger and older bird from emergency farm slaughter) were used for this study and described using basic gross anatomical and histological techniques, supplemented by scanning electron microscopy. The findings of the study were compared with the relevant literature. The oral and pharyngeal cavities could not be morphologically separated and formed a single cavity. This cavity was dorso-ventrally flattened and clearly divided, both on the floor and the roof, into rostral pigmented and caudal non-pigmented parts. The non-pigmented floor housed the tongue and laryngeal mound which had a wide glottis and no papillae. The choana was triangular-shaped, with a small caudo-lateral fold on either side, and was situated in the nonpigmented part of the roof. Caudal to the choana were two rounded pharyngeal folds with a pitted ventral surface. A small bilateral projection from the caudo-lateral edge consisted mainly of diffuse lymphoid tissue. The pharyngeal folds contained numerous large simple branched tubular mucus-secreting glands as well as large accumulations of lymphoid tissue. The pigmented regions of the roof and floor were aglandular and lined by a keratinised stratified squamous epithelium which, particularly in the roof, contained numerous Herbst corpuscles in the underlying connective tissue. SEM revealed the surface to be composed of sheets of desquamating flattened polygonal cells. The non-pigmented regions were glandular and lined by a non-keratinised stratified squamous epithelium. Surface cells displayed a pattern of microplicae or microvilli while individual surface cells were seen to desquamate. The connective tissue housed small, simple tubular and large, simple branched tubular mucus-secreting glands, Herbst corpuscles (only absent from the pharyngeal folds and proximal oesophagus), lymphoid tissue, blood vessels and nerves. The glands of the upper digestive tract were polystomatic and named as follows according to their location: Caudal intermandibular, lingual, crico-arytenoid, oral angular, caudal palatine, pharyngeal and oesophageal. The openings of the glands to the surface were seen on SEM as variably sized holes on the surface, some being obscured by mucus secretions from the underlying glands. Taste receptors were sparse and present only in the caudal non-pigmented oropharyngeal floor, tongue root and proximal oesophagus. Accumulations of lymphoid tissue were identified at the junction between the two regions of the roof, and in the non-pigmented roof, the non-pigmented floor, tongue ventrum, root and frenulum, proximal oesophagus and pharyngeal folds. The consistent dense accumulation of lymphoid tissue in the pharyngeal folds constituted pharyngeal tonsils (Lymphonoduli pharyngeales). The lymphoid tissue of the non-pigmented floor was visible macroscopically as round raised nodules. Specific, unnamed larger lymphoid tissue aggregations were located at the junction of the tongue ventrum and frenulum and in the small folds lateral to the choana. Surface morphology, as seen by SEM, revealed a pattern of microridges on the surface cells of the keratinised areas, whereas the surface cells of the non-keratinised areas displayed microplicae, microvilli and cilia. Microvilli and cilia were associated with the gland openings and ducts. The proximal oesophagus was a cylindrical tube with a longitudinally folded mucosa and displayed the typical tissue layers described in birds. The mucosa was formed by a nonkeratinised stratified epithelium which on SEM showed minimal surface desquamation. The lamina propria contained numerous simple tubular mucus-secreting glands which sometimes branched and occasional diffuse lymphoid tissue aggregations. The gland openings to the surface were seen on SEM as small and large dark holes. The muscularis mucosae was very prominent and was a longitudinal smooth muscle layer separating the mucosa from the submucosa. The tunica muscularis was composed of a thicker inner circular and a thinner outer longitudinal smooth muscle layer surrounded by the outer loose connective tissue forming the tunica adventitia. The emu tongue was divided into a body and a root. The body was triangular, dorso-ventrally flattened, pigmented and displayed caudally directed lingual papillae on both the lateral and caudal margins. The root, a more conspicuous structure in comparison to other ratites, was triangular, with a raised bulbous component folding over the rostral part of the laryngeal fissure. The lingual skeleton was formed by the triangular-shaped paraglossum (hyaline cartilage), forming the core of the tongue body, and the rostral projection of the basihyale, ventral to the paraglossum. Following the general trend in ratites, the emu tongue was greatly reduced in comparison to the bill length and specifically adapted for swallowing during the cranioinertial method of feeding employed by palaeognaths. The tongue was invested by a non-keratinised stratified squamous epithelium. The glands in the connective tissue formed the bulk of the parenchyma and were composed of both small simple tubular and large simple branched tubular mucus-secreting glands similar to those seen in the oropharynx. The lingual glands were grouped as follows: dorsal and rostro-ventral (large glands), caudo-ventral and radical (large and small glands) and frenular (small glands). The large glands were visible macroscopically as doughnut-shaped structures. Melanocytes were absent from the tongue ventrum and occasionally from the tongue root. Lymphoid tissue was absent from the tongue dorsum. Herbst corpuscles were present in the tongue body and root and generally closely associated with the large mucus-secreting glands. The surface morphology varied in the different regions of the tongue. The dorsal and rostro-ventral tongue body showed individual desquamating cells and large gland openings only, the caudo-lateral ventrum showed less desquamation and both large and small openings. The mid-ventral aspect had an undulating uneven appearance with round raised cells on the surface which were densely packed with microvilli. Very large, large and small openings were present in this region and ciliated cells occurred in the vicinity of gland openings. This study presented various unique findings regarding the morphology of the emu oropharynx compared to other ratites. Although the sense of taste has been confirmed in many avian species, this study presented the first evidence of taste in the emu and ratites in general and suggests the possibility of taste being previously overlooked in the other birds studied (ostrich and greater rhea). The tongue root of the emu was clearly defined and is unique in structure and possible function amongst the ratites and other birds. Previously unmentioned functions of the emu tongue revealed by this study include: touch (Herbst corpuscles), taste (taste bud), lubrication and mechanical protection (mucus-secreting glands), immunological (lymphoid tissue) and digestive (swallowing). It was also noted that the various structures and organs of the oropharynx revealed important and often interesting differences between the emu and the other ratites documented. The prominent serrations of the rostral mandibular tomia of the emu also appear to be unique amongst ratites. The presence and wide distribution of Herbst corpuscles within the emu oropharynx and tongue show these areas to be highly sensitive to touch. The caudo-lateral projections of the pharyngeal folds effectively formed pharyngeal tonsils, a feature not apparent in other ratites. Despite the differences noted between the emu and other ratites it was possible to discern a common pattern of structures and features, with their modifications, both within and forming the oropharynx in this group of birds.Dissertation (MSc)--University of Pretoria, 2009.
Anatomy and Physiology
unrestricted
20
Herrera, Endoqui M. (Martín). "Study of the morphological features in the Spitzer Survey of Stellar Structure in Galaxies (S⁴G)." Doctoral thesis, University of Oulu, 2016. http://urn.fi/urn:isbn:9789526213231.
Full textAbstract:
Abstract
Conspicuous morphological features such as rings, ringlenses, lenses, barlenses, and spiral arms are observed in many nearby disk galaxies. These features are believed to form due to the so-called secular evolution after the galaxies were formed, which means that their disks evolve in a more passive fashion and in longer timescales, compared to their formation processes. This slow evolution of disks is due to the effect of non-axisymmetric potentials, among which, a bar potential is perhaps the most effective of all. Strong rotating bars redistribute angular momentum and material through the disks of galaxies very effciently, and produce resonances. At these resonances the material is trapped and starts forming stars, creating beautiful rings. However, rings are not the only structure observed in disk galaxies. There are also spiral arms that, might or might not be created by bars. Other type of structures are lenses, which in images appear as flat light distributions with sharp edges, and ringlenses, whose appearance is intermediate between those of rings and lenses. Also, there are barlenses, which are conspicuous lens-like structures embedded in bars, and have been suggested to be the more face-on counterparts of Boxy/Peanut/X-shaped bulges. The study of the physical properties of all these structures provides a tool to investigate the mechanisms that create them and hence, to determine which are the processes that drive the slow evolution of galaxies.
In this thesis I study the morphological structures using mainly data from the Spitzer Survey of Stellar Structure in Galaxies (S⁴G), by means of their sizes, orientations, shapes and colors. The S⁴G contains images of ~ 2500 nearby galaxies of all Hubble types at 3.6 and 4.5 μm, allowing a dust free view of the old stellar population which is subject of the secular evolution.
Among the results presented in this thesis and the respective companion papers are the following. A catalog that contains the sizes, ellipticities and position angles of the morphological features in the S⁴G was created. This catalog also includes the measurements of the pitch angles of spiral arms. There is a corroboration of previous results showing that different types of morphological features appear in galaxies with different Hubble stages and bar families, and a confirmation of the resonant nature of rings but also of a high fraction of lenses and ringlenses. There is also an observation indicating that low mass galaxies lack nuclear structures such as nuclear rings due to the lack of inner Lindblad resonances caused by their low central mass concentrations. Observational evidence is presented indicating that a fraction of inner lenses in unbarred galaxies might be former barlenses of which the "thin bar" has probably dissolved or it is too faint to be detected.
The sizes of barlenses show a tight linear correlation with those of bars, being the size of the barlens typically half the size of the bar. The study of the optical colors of barlenses reveals their similarity with bars, giving observational evidence that their stellar populations are similar, and distinguishes them from disks and nuclear regions. The orientations of barlenses with respect to that of bars and disks reveal that barlenses are vertically thick structures. All these results support the idea that barlenses are the vertically thick inner parts of bars and hence relate them observationally to Boxy/Peanut/X-shaped bulges.
These results and others are published in a series of original papers in which I have collaborated and that are appended at the end of this work.
21
Johnson, Victoria Louise. "Regulation of biochemical and morphological features of chemical- and receptor-mediated apoptosis in Jurkat T cells." Thesis, University of Leicester, 2000. http://hdl.handle.net/2381/29651.
Full textAbstract:
Evidence suggests that the signalling events which occur after apoptotic stimulation, define two basic mechanisms for the induction of apoptosis. The first is dependent on signalling via the mitochondria and the second is dependent upon signalling directly from the death receptors. After induction of apoptosis, there is a convergence in signalling at the level of caspase activation and subsequent biochemical and morphological changes. Therefore the efficacy of various inhibitors of apoptosis is dependent upon the initiating signal. In order to understand the apoptotic pathway, the mechanisms by which these inhibitors regulate chemical- and receptor-mediated apoptosis must be understood. The anti-apoptotic oncoprotein, Bcl-2, was shown to inhibit both staurosporine and Fas-mediated apoptosis in a manner which was partially dependent upon the level of Bcl-2 protein expressed. During both staurosporine and Fas-induced apoptosis Bcl-2 acted downstream of caspase-8 activation. High levels of Bcl-2 expression did not effectively inhibit apoptosis induced by anti-Fas but inhibited AICD by inhibiting the secretion of sFasL at a level above caspase-8 activation. The peptide based caspase inhibitor z-VAD-FMK resulted in a novel nuclear morphological change, characterized by partially condensed nuclear morphology and could be dissociated from the externalisation of PS, HMW DNA fragmentation and preceded the appearance of a condensed nuclear morphology during staurosporine-induced apoptosis. Furthermore, the appearance of the partially condensed nuclear morphology was independent of effector caspases. The nuclear morphological change occurred downstream of cytochrome c release, disruption of mitochondrial membrane potential and could be inhibited by Bcl-2. Finally the role of caspase-3 and DFF40/45 were examined in staurosporine- and Fas-mediated apoptosis. Using the MCF-7 cell line, it was found that caspase-3 and DFF40/45 were dispensable for the formation of HMW DNA fragments. Furthermore, the serine protease inhibitor, TPCK which has been previously shown to inhibit oligonucleosomal-length DNA fragmentation, was found to exert this effect by acting downstream of DFF40 activation.
22
Muellerleile, Joan Thérèse Polesnak. "Crystallization behavior and morphological features of two LARC polyimides and local orientation studies of two semicrystalline model composites." Diss., Virginia Tech, 1991. http://hdl.handle.net/10919/39082.
Full textAbstract:
Results are presented for two unrelated studies. The primary topic involved the crystallization behavior and morphological features of two polyimides, namely LARCCPI (Langley Research .Center Crystalline folyimide) and LARC-TPI (Thermoplastic folyimide). The LARC-CPI study first considered feature~ affecting crystallization behavior including inherent viscosity, crystallization temperature, and melt temperature and time. Data were analyzed using the A vrami analysis. Morphological features were investigated using techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM), and small angle x-ray scattering (SAXS). Permanganic etching combined with SEM successfully revealed morphological detail, further supported by TEM data. These data support the Avrami analysis results. SAXS data reflected the influence of several crystalliz.ation variables on the long spacing. SAXS results also revealed the presence of a broad second scattering peak for semicrystalline samples appearing in the same position regardless of crystalliz.ation temperature or inherent viscosity. Molecular modelling predicted a low-energy helical conformation with a near-periodic repeat distance corresponding to the second SAXS peak. This conformation is offered as a tentative explanation for that peak. Finally, the effe.ct of nucleating agent on the recrystalliz.ability of a higher inherent viscosity LARC-CPI was considered. One of several nucleators appeared effective in enhancing recrystallization.
The LARC-TPI study involved the development of a thermal cycle based upon crystalliz.ation kinetics results, allowing the successful recrystallization of LARC-TPI following exposure to elevated temperatures. This cycle was then used to modify an existing composite fabrication process to produce semicrystalline composites. Two carbon fiber types were utilized to make composites via both fabrication cycles. These composites were evaluated using several techniques.
The second unrelated project examined very localized orientation behavior in two types of semi crystalline superstructure using FTIR microspectroscopy. Results were obtained utilizing linear dichroism for orientation within spherulitic and transcrystalline superstructure in poly(glycolide co-lactide) and isotactic polypropylene. An increase in orientation on an absolute basis as a function of position was successfully measured. Orientation function values were higher on an absolute basis for the transcrystalline superstructure. However, the sign of the isotactic polypropylene spherulite orientation function values was the opposite of what was anticipated. These results were considered in light of spherulite W AXS data also obtained.Ph. D.
23
Poškienė, Lina. "Gastrointestinės stromos navikų morfologinės charakteristikos ir ligos progresavimo sąsajų tyrimas." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140904_150128-30363.
Full textAbstract:
Gastrointestinės stromos tumorai (GIST) – dažniausi mezenchiminės kilmės virškinamojo trakto navikai, kurie pradėti identifikuoti ir diagnozuoti tik per pastaruosius 25 m. GIST, pagal ligos progresavimo reliatyvią riziką, klasifikuojami į rizikos kategorijas, kurių nustatymas 2002 m. Nacionalinių sveikatos institutų sutarimu (NSI) paremtas dviem kintamaisiais: naviko dydžiu ir navikinių ląstelių mitozių skaičiumi 50 DPRL, kurių apimamas plotas įvairių studijų ir rekomendacijų duomenimis varijuoja nuo 5 mm² iki 11,9 mm². Neaišku, kaip netikslus mitozių skaičius įtakoja rizikos kategorijos nustatymą bei jų sąsajas su ligos progresavimu. Nors atliktose didžiausiose GIST studijose teigiama, kad, esant identiškiems morfologiniams požymiams, skrandžio GIST prognozė geresnė, kiti tyrėjai nustatė morfologinius požymius lemiančius geresnę šių navikų prognozę. Esant prieštaringoms nuomonėms, tyrimo metu nustatėme ir palyginome skirtingų lokalizacijų GIST morfologinius požymius ir prognozę. NSI klasifikacijoje buvo pastebėta, kad ligos prognozę įtakoja ir GIST histologinis fenotipas, tačiau tuomet nebuvo pakankamai atliktų studijų, paneigiančių ar patvirtinančių šiuos teiginius, todėl detaliai nagrinėjome skirtingų histologinių fenotipų GIST morfologinius požymius ir jų įtaką ligos prognozei bei kitų morfologinių požymių: naviko dydžio, mitozių skaičiaus, ląstelingumo, branduolių polimorfizmo ir nekrozės sąsajas su ligos prognoze.Gastrointestinal stromal tumours (GIST) – the most common mesenchymal tumours of the gastrointestinal tract which have been identified and diagnosed in the past 25 years. GIST, according to relative risk of disease progression, are classified in risk categories which under the agreement of the National Institutes of Health (2002) were based on two variables: tumour size and mitotic count in 50 HPF, which total area varies from 5 mm² to 11.9 mm². There is no consensus what area is sufficient for the counting of mitoses. Thus, we compare number of GIST tumor cell mitoses in different sized areas and evaluated the impact of mitotic rate changes in determination of risk categories and their relation to the progression of the disease. According to the data of largest GIST study, disease prognosis is also influenced by tumour localization, other researchers found morphological features of these tumours leading to a better prognosis. Thus, we identified and compared the different localizations of GIST morphological features and prognosis. It was observed that disease prognosis is also determined by the tumour histological phenotype, but up till now the controversial results of histological phenotypes relationship to disease prognosis are published. We set morphological features of different GIST histological phenotypes and evaluate their relation to disease progression, evaluate the impact of GIST morphological features to disease prognosis.
24
Honjo, Kiyoko. "Development of a novel method for analyzing morphological features of wood fibers and its application to selected tree species." Kyoto University, 2009. http://hdl.handle.net/2433/123987.
Full textAbstract:
Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第14675号
農博第1757号
新制||農||969(附属図書館)
学位論文||H21||N4448(農学部図書室)
UT51-2009-D387
京都大学大学院農学研究科森林科学専攻
(主査)教授 中野 隆人, 教授 杉山 淳司, 准教授 髙部 圭司
学位規則第4条第1項該当
25
Kabir, Mitra. "Prediction of mammalian essential genes based on sequence and functional features." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/prediction-of-mammalian-essential-genes-based-on-sequence-and-functional-features(cf8eeed5-c2b3-47c3-9a8f-2cc290c90d56).html.
Full textAbstract:
Essential genes are those whose presence is imperative for an organism's survival, whereas the functions of non-essential genes may be useful but not critical. Abnormal functionality of essential genes may lead to defects or death at an early stage of life. Knowledge of essential genes is therefore key to understanding development, maintenance of major cellular processes and tissue-specific functions that are crucial for life. Existing experimental techniques for identifying essential genes are accurate, but most of them are time consuming and expensive. Predicting essential genes using computational methods, therefore, would be of great value as they circumvent experimental constraints. Our research is based on the hypothesis that mammalian essential (lethal) and non-essential (viable) genes are distinguishable by various properties. We examined a wide range of features of Mus musculus genes, including sequence, protein-protein interactions, gene expression and function, and found 75 features that were statistically discriminative between lethal and viable genes. These features were used as inputs to create a novel machine learning classifier, allowing the prediction of a mouse gene as lethal or viable with the cross-validation and blind test accuracies of ∼91% and ∼93%, respectively. The prediction results are promising, indicating that our classifier is an effective mammalian essential gene prediction method. We further developed the mouse gene essentiality study by analysing the association between essentiality and gene duplication. Mouse genes were labelled as singletons or duplicates, and their expression patterns over 13 developmental stages were examined. We found that lethal genes originating from duplicates are considerably lower in proportion than singletons. At all developmental stages a significantly higher proportion of singletons and lethal genes are expressed than duplicates and viable genes. Lethal genes were also found to be more ancient than viable genes. In addition, we observed that duplicate pairs with similar patterns of developmental co-expression are more likely to be viable; lethal gene duplicate pairs do not have such a trend. Overall, these results suggest that duplicate genes in mouse are less likely to be essential than singletons. Finally, we investigated the evolutionary age of mouse genes across development to see if the morphological hourglass pattern exists in the mouse. We found that in mouse embryos, genes expressed in early and late stages are evolutionarily younger than those expressed in mid-embryogenesis, thus yielding an hourglass pattern. However, the oldest genes are not expressed at the phylotypic stage stated in prior studies, but instead at an earlier time point - the egg cylinder stage. These results question the application of the hourglass model to mouse development.
26
Vienažindytė, Sandra. "Kalninės pušies Pinus mugo Turra porūšių morfologinė ir genetinė įvairovė Kuršių nerijoje." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2012. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2012~D_20120620_151428-84554.
Full textAbstract:
Magistro darbe analizuojami Kalninės pušies Pinus mugo Turra Kuršių nerijoje morfologiniai ir genetiniai požymiai, galintys identifikuoti jų porūšius.
Tyrimo objektas – Kalninė pušis Pinus mugo Turra, auganti Kuršių nerijos teritorijoje.
Šio tyrimo tikslas – įvertinti Pinus mugo porūšių morfologinius požymius Kuršių nerijoje bei nustatyti, šioje teritorijoje labiausiai išplitusio Pinus mugo porūšio nothssp. rotundata Link įvairių morfotipų taksonominę priklausomybę pagal raktinius morfologinius ir genetinius požymius.
Tyrimo metodai – morfologinių ir genetinių požymių analizė.
Tyrimo rezultatai. Raktiniai morfologiniai požymiai rodo, kad Kuršių nerijoje auga pagrindiniai trys P. mugo Turra porūšiai: mugo (įskaitant pseudopumilio), nothssp. rotundata Link ir ssp. uncinata Ram. Labiausiai išplitęs ir morfologiškai įvairus yra nothssp. rotundata Link porūšis. Iš raktinių kankorėžių morfologinių požymių informatyviaisiais identifikuojant porūšius buvo kankorėžio apofizio gylis ir simetriškumas.
DNR tyrimas atskleidė, kad P. mugo porūšiai pagal savo per tėvinę liniją paveldimą chloroplasto DNR, iš esmės nesiskiria vienas nuo kito. Kiek ženkliau išsiskiria tik P. mugo ssp. mugo (krūmas) nuo P. mugo ssp. uncinata Ram (medžio), kas patvirtina P. mugo porūšių laisvo tarpusavio kryžminimosi hipotezę, taip pat tai, kad taksonomiškai tai yra vienos rūšies porūšiai, o ne skirtingos rūšys. Visi tirti P. mugo porūšiai laisvai kryžminasi tarp savęs, dalijasi bendru chloroplasto DNR genomu... [toliau žr. visą tekstą]Mountain pine Pinus mugo Turra subspieces morphological and genetic variety in Kursiu nerija, that can identify subspieces was investigated in the work of master thesis. Object of the work – Pinus mugo Turra growing in Kuršių nerija territory. Method of the work – morphological and genetic features analysis. The results of the work. Key morphological features showed that three Pinus mugo Turra main subspieces growing in Kursiu nerija: mugo (including pseudopumilio), nothssp. rotundata Link and ssp. uncinata. The most widespread and morphologically variable is nothssp. rotundata Link. The informative key morphological features to identify subspieces were cone apophyses depth and symmetry. DNA analysis revealed that P. mugo varieties according to their own through the parental line inherited chloroplast DNA are not significantly different from each other. More different by DNA analysis are Pinus mugo ssp. mugo (shrub) and Pinus mugo ssp. uncinata Ram (tree) which confirming hypothesis of Pinus mugo subspieces free interbreeding. Also it is confirming hypothesys that taxonomically it is one type of subspieces, but not diferrent species. All of the explored Pinus mugo subspieces are free interbreeding between each other, sharing a common chloroplast DNA genome and in evolution the origin is from one parental spiece which spread to different eco-climatic niches and evolved to subspieces reflected by morphotypes. It is likely that this morphotypical variety should be... [to full text]
27
Brucker, Julia [Verfasser], and Christian [Akademischer Betreuer] Stegmann. "Simultaneous Modelling of the Morphological and Spectral Features of the Pulsar Wind Nebula HESS J1825-137 in TeV Gamma rays / Julia Brucker. Betreuer: Christian Stegmann." Erlangen : Universitätsbibliothek der Universität Erlangen-Nürnberg, 2013. http://d-nb.info/1032393904/34.
Full text
28
Vayá, Salort Carlos. "Characterization and processing of atrial fibrillation episodes by convolutive blind source separation algorithms and nonlinear analysis of spectral features." Doctoral thesis, Universitat Politècnica de València, 2010. http://hdl.handle.net/10251/8416.
Full textAbstract:
Las arritmias supraventriculares, en particular la fibrilación auricular (FA), son las enfermedades cardíacas más comúnmente encontradas en la práctica clínica rutinaria. La prevalencia de la FA es inferior al 1\% en la población menor de 60 años, pero aumenta de manera significativa a partir de los 70 años, acercándose al 10\% en los mayores de 80. El padecimiento de un episodio de FA sostenida, además de estar ligado a una mayor tasa de mortalidad, aumenta la probabilidad de sufrir tromboembolismo, infarto de miocardio y accidentes cerebrovasculares. Por otro lado, los episodios de FA paroxística, aquella que termina de manera espontánea, son los precursores de la FA sostenida, lo que suscita un alto interés entre la comunidad científica por conocer los mecanismos responsables de perpetuar o conducir a la terminación espontánea de los episodios de FA.
El análisis del ECG de superficie es la técnica no invasiva más extendida en la diagnosis médica de las patologías cardíacas. Para utilizar el ECG como herramienta de estudio de la FA, se necesita separar la actividad auricular (AA) de las demás señales cardioeléctricas. En este sentido, las técnicas de Separación Ciega de Fuentes (BSS) son capaces de realizar un análisis estadístico multiderivación con el objetivo de recuperar un conjunto de fuentes cardioeléctricas independientes, entre las cuales se encuentra la AA. A la hora de abordar un problema de BSS, se hace necesario considerar un modelo de mezcla de las fuentes lo más ajustado posible a la realidad para poder desarrollar algoritmos matemáticos que lo resuelvan. Un modelo viable es aquel que supone mezclas lineales. Dentro del modelo de mezclas lineales se puede además hacer la restricción de que estas sean instantáneas. Este modelo de mezcla lineal instantánea es el utilizado en el Análisis de Componentes Independientes (ICA).Vayá Salort, C. (2010). Characterization and processing of atrial fibrillation episodes by convolutive blind source separation algorithms and nonlinear analysis of spectral features [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/8416
Palancia
29
Fusco, Roberta <1985>. "Lesion detection and classification in breast cancer: evaluation of approaches based on morphological features, tracer kinetic modelling and semi-quantitative parameters in MR functional imaging (DCE-MRI)." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5302/.
Full textAbstract:
The diagnosis, grading and classification of tumours has benefited considerably from the development of DCE-MRI which is now essential to the adequate clinical management of many tumour types due to its capability in detecting active angiogenesis.
Several strategies have been proposed for DCE-MRI evaluation. Visual inspection of contrast agent concentration curves vs time is a very simple yet operator dependent procedure, therefore more objective approaches have been developed in order to facilitate comparison between studies. In so called model free approaches, descriptive or heuristic information extracted from time series raw data have been used for tissue classification. The main issue concerning these schemes is that they have not a direct interpretation in terms of physiological properties of the tissues.
On the other hand, model based investigations typically involve compartmental tracer kinetic modelling and pixel-by-pixel estimation of kinetic parameters via non-linear regression applied on region of interests opportunely selected by the physician. This approach has the advantage to provide parameters directly related to the pathophysiological properties of the tissue such as vessel permeability, local regional blood flow, extraction fraction, concentration gradient between plasma and extravascular-extracellular space. Anyway, nonlinear modelling is computational demanding and the accuracy of the estimates can be affected by the signal-to-noise ratio and by the initial solutions.
The principal aim of this thesis is investigate the use of semi-quantitative and quantitative parameters for segmentation and classification of breast lesion. The objectives can be subdivided as follow: describe the principal techniques to evaluate time intensity curve in DCE-MRI with focus on kinetic model proposed in literature; to evaluate the influence in parametrization choice for a classic bi-compartmental kinetic models; to evaluate the performance of a method for simultaneous tracer kinetic modelling and pixel classification; to evaluate performance of machine learning techniques training for segmentation and classification of breast lesion.
30
Sejaphala, Makoma Doncy. "The morpheme le in Northern Sotho : a linguistic analysis." Thesis, University of Limpopo (Turfloop Campus), 2010. http://hdl.handle.net/10386/153.
Full textAbstract:
Thesis (M.ED.) --University of Limpopo, 2009.This study focuses on the morpheme le in Northern Sotho. It is sometimes confusing to establish the correct semantic function which the morpheme le expresses; and also to classify it into a certain word category. This study suggests the morphological features which the morpheme le bears in terms of its word categorization. The morpheme le in Northern Sotho can be used as a conjunction, a demonstrative pronoun, an agreement, a preposition, a copulative, an adverb and a complement as well. It is suggested in this study, ways of identifying the semantic function of the morpheme le in various contexts. This study reflects that the morpheme le in Northern Sotho can be used to denote: possession, accompaniment, location, additive focus, existentialism and honorifics.
31
Mackových, Marek. "Regresní analýza EKG pro odhad polohy srdce vůči měřicím elektrodám." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-220859.
Full textAbstract:
This work focuses on the regression analysis of morphological parameters calculated from the ECG for estimating the position of the heart to the measuring electrodes. It consists of a theoretical analysis of the problems of ECG recording and description of the data obtained from experiments on isolated animal hearts. On the theoretical part is followed by a description of the calculation parameters suitable for regression analysis and their application in the training and testing of the following regression models to estimate the position of the heart to the measuring electrode.
32
Colaninno, Nicola. "Semi-automatic land cover classification and urban modelling based on morphological features : remote sensing, geographical information systems, and urban morphology : defining models of land occupation along the Mediterranean side of Spain." Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/396219.
Full textAbstract:
From a global point of view, as argued by Levy (1999), the modern city has undergone radical changes in its physical form, either in terms of territorial expansion as well as in terms of interna! physical transformations. Today, approximately 75% of the European population lives in urban areas ,which makes the urban fulure of the conlinent a major cause of concern (Brazil, Cavalcanti, & Longo, 2014). lndeed, the demand for urban land, both within and around the cities, is becoming increasingly acule (European Environmenl Agency, 2006).
Ouring the last decades, also Spain has been undergoing an important process of urban growth, which has implied the consumption of a large amounl of land, al hough the overall population growth rale, mostly along certain specific geographic areas, has remained at least unchanged or even, in sorne cases, il has also decreased. Such a phenomenon has been quite remarkable along the Mediterranean side.
As argued by Gaja (2008), the urban development in Spain has been strongly linked to the model of economic development , which relies, since its launch in the 50's, onlhree main factors , i.e.:emigration, building, and mass tourism. Nowadays , in Spain, and mostly along the Medilerranean side, several urban areas are facing important phenomena of urban sprawl, also feared by he European Union.
An accurate information about the pattern of land use/land cover, over time, is a fundamental requirement for a better understanding of the urban models. Currently, even though plenty of approaches to the image classification, through Remote Sensing (RS) techniques, have been advanced, Land Cover/Land Use classification is still an exciting challenge (Weng, 2010).
Actually, the increasing development of RS and GIS technologies, during the last decades, has provided further capabiliies for measuring, analysing, understanding, modelling the "physical expressions" of urban growth phenomena, either in terms of pattern and process (Bhatta, 2012), and based on land use/land cover mapping and change delection over time.
Based on such a technological approach, here we first aim to set up a suitable methodology for detecting generalized land cover classes based on an assisted automatic (or semi-aulomatic) pixel-based approach, calibrated upon Landsat Thematic Mapper (TM) mullispectral imagery, at 30 meters of spatial resolution. Beside, through the use of Geographical lnformation Syslem (GIS) we provide a spatial analysis and modelling of different urban models, from a morphological standpoint, in order to define the main pattern of land occupation al municipal scale, and along the Mediterranean side of Spain, al the year 2011.
We focus on two main issues. On one hand, RS techniques have been used to set up a proper semi-automatic classification methodology, based on the use of Landsat imagery, capable of handling huge geographical areas quickly and efficiently. This process is basically aimed to detect the urban areas, at the year 2011, along the Mediterranean side of Spain, depending on the administrative division of Autonomous Communities. On the other hand, the spatial patterns of urban settlements have been analysed by using a GIS platform for quantifying a set of spatial metrics about the urban form. Hence, once get the quantification of different morphological features, including the analysis aboul either the urban profile, the urban texture, and the street network pattern, an automatic classification of different urban morphological models has been proposed, based on a stalistical approaches, namely factor and cluster analysisDesde un punto de vista global,como sostiene Levy (1999), la ciudad moderna ha experimentado cambios radicales en su forma física, ya sea en términos de expansión territorial, así como en términos de transformaci ones internas. Hoy en día, aproximadamente el 75% de la población europea vive en zonas urbanas, lo que hace del futuro urbano delcontinente, una causa importante de preocupación (Brasil, Cavalcanti, y Longo, 2014). De hecho, la demanda de suelo urbano, dentro y alrededor de las ciudades , es cada vez más aguda (Agencia Europea de Medio Ambiente,2006). Durante las últimas décadas, también España ha experimentado un importante proceso de crecimiento urbano que ha implicado el consumo de una gran cantidad de tierra, aunque la tasa de crecimiento de la población en general, sobre todo a lo largo de ciertas áreas geográficas específicas , se ha mantenido al menos sin cambios o incluso, en algunos casos, también ha disminuido. Este fenómeno ha sido muy evidente a lo largo de la vertiente mediterránea. Como sostiene Gaja (2008), el desarrollo urbano en España se ha visto fuertemente vinculado con el modelo de desarrollo económico, que se basa, desde su lanzamiento en la década de los 50,en tres factores principales, a saber: la emigración, la construcción y el turismo de masas. Hoy en día, en España, y sobre todo a lo largo de la vertiente mediterránea, varias zonas urbanas se enfrentan a fenómenos importantes de expansión urbana, también temidos por la Unión Europea. Al respecto,un requisito fundamental para mejorar la comprensión y el estudio de los modelos urbanos es obtener en eltiempo una información precisa sobre los patrones de cubiertas y uso de suelo. Actualmente, a pesar de la existencia de numerosos métodos para la clasificación de imágenes digitales a través de técnicas de teledetección, para ext raer información sobre cobertura/uso de suelo, este enfoque sigue siendo un reto apasionante (Weng, 2010). El creciente desarrollo de las tecnologías de RS y GIS, durante las últimas décadas, ha proporcionado nuevas capacidades para medir, analizar, comprender, y modelar las "expresiones físicas" de los fenómenos de crecimiento urbano, en términos de patrones y procesos (Bhatta, 2012), y con base en el mapeo y análisis de cambios de cobertura/uso de suelo a través el tiempo. Basándose en un enfoque tecnológico, el primero objetivo es establecer una metodología adecuada para la detección de clases de cobertura de la tierra generalizadas que encuentra su fundamento en una asistido automático (o semiautomático), enfoque basado en píxeles, calibradas en Landsat Thematic Mapper (TM) imágenes multiespectrales, a 30 metros de resolución espacial. Al lado, a través del uso del Sistema de Información Geográfica (SIG), es posible proveer un análisis espacial y la modelización de diferentes modelos urbanos, desde un punto de vista morfológico, con el fin de definir el patrón principal de la ocupación del suelo a escala municipal a lo largo de la vertiente mediterránea de España, en el año 2011. En particular no enfocamos en dos cuestiones principales. Por un lado, las técnicas de RS se han utilizado para establecer una metodología de clasificación semi-automático adecuada, basada en el uso de imágenes Landsat, capaz de manejar grandes zonas geográficas de forma rápida y eficiente. Este proceso, básicamente, va dirigido a detectar las áreas urbanas, en el año 2011, a lo largo de la vertiente mediterránea de España, según la división administrativa de las Comunidades Autónomas. Por otro lado, los patrones espaciales de asentamientos urbanos han sido analizados mediante el uso de una plataforma GIS para cuantificar un conjunto de métricas espaciales sobre la forma urbana. Finalmente, una vez obtenida la cuantificación de diferentes características morfológicas, se ha proporcionado una clasificación automática de los diferentes modelos morfológicos urbanos, basada en un enfoque estadístico, es decir, análisis factorial y clúster.
33
Helmling, Stephanie [Verfasser]. "Identification of Mixed Tropical Hardwood (MTH) by characteristic morphological features – a contribution to species protection : Identifizierung von Mixed Tropical Hardwood (MTH) mittels charakteristischer morphologischer Merkmale - ein Beitrag zum Artenschutz / Stephanie Helmling." Hamburg : Staats- und Universitätsbibliothek Hamburg Carl von Ossietzky, 2020. http://d-nb.info/1225481325/34.
Full text
34
Sunčica, Poček. "Specifičnosti antropološkog statusa mladih odbojkašica Vojvodine." Phd thesis, Univerzitet u Novom Sadu, Fakultet sporta i fizičkog vaspitanja u Novom Sadu, 2015. https://www.cris.uns.ac.rs/record.jsf?recordId=95381&source=NDLTD&language=en.
Full textAbstract:
Na uzorku od 358 devojčica sa teritorije Vojvodine, uzrasta od 11,50 – 16 decimalnih godina, od kojih 186 odbojkašica (najmanje tri godine u trenažnom procesu),i 172 devojčice koje se ne bave organizovanom fizičkom aktivnošću, sprovedeno je istraživanje morfoloških karakteristika, motoričkih i intelektualnih sposobnosti. Cilj istraživanja je bio da se utvrde specifičnosti mladih odbojkašica u odnosu na devojčice koje se ne bave organizovanom fizičkom aktivnošću, testiranjem kako kvantitativnih, tako i razlika u strukturi sposobnosti definisanih predmetom istraživanja. Uvidom u rezultate, možemo zaključiti da se devojčice koje se bave odbojkom odlikuju većim vrednostima telesne visine i telesne mase, obima grudi,nadlaktice i podlaktice u odnosu na devojčice koje se ne bave organizovanom fizičkom aktivnošću. Iako u varijablama za procenu potkožnog masnog tkiva nijedošlo do statistički značajnih razlika, u dve od tri grupe vidimo da su kod odbojkašica manje vrednosti varijabli kožnih nabora, ali ne i statistički značajno manje.Navedene razlike grupa devojčica u prostoru morfoloških karakteristika su proizašle na osnovu procesa selekcije i rasta i razvoja (telesna visina, volumen i masa tela), dok se manje vrednosti u potkožnom masnom tkivu odbojkašica mogu pripisatitrenažnom tretmanu bavljenja odbojkom. Na osnovu rezultata primenjene kongruencije ekstrahovanih faktora, možemo zaključiti da se grupe devojčica nerazlikuju u strukturi prvih izolovanih faktora – koji definišu strukturu morfološkog prostora, ali da postoji razlika u strukturi drugih i trećih faktora koji definišuvarijable za procenu motoričkih sposobnosti i inteligencije. Posebno je važno sagledati razliku u strukturi drugih faktora po uzrastu, odnosno važnostpojedinih motoričkih varijabli gde se vidi da je na uzorku odbojkašica motorički prostor mnogo homogeniji, jasnije definisan, sa dominacijom varijabliza procenu intenziteta i trajanja ekscitacije i struktuiranja kretanja. Na osnovu sprovedenog istraživanja o specifičnostima antropološkog prostoradve grupe devojčica starijeg školskog uzrasta, a u skladu sa postavljenim ciljevima i zadacima i u kome su proveravane definisane hipoteze, može se generalnozaključiti da se devojčice koje su u trenažnom programu – odbojkašice statistički značajno razlikuju u morfološkom i motoričkom prostoru od ispitanica kojese ne bave organizovanom fizičkom aktivnošću, dok u intelektualnom funkcionisanju dve grupe ispitanica nisu uočene statistički značajne razlike.A research of morphological features, motor abilities and intelligence was carried out on the sample of 358 girls from the territory of Vojvodina, 11, 50 – 16 years old, out of which 186 female volleyball players (at least three years in training process) and 172 girls that do not practice organized physical activities. The aim of this study was to determine the specificity of young volleyball players compared to girls who are not involved in physical activity, testing of quantitative as well as differences in the structure of skills defined by the subject of research. After examining the results, we can conclude that girls engaged in volleyball are characterized by higher values of body height and body weight, chest circumference, upper arm and forearm girth inrelation to girls who are not involved in physical activity. Although there were no statistically significant differences in the variables for estimating body fat, on the basis of the differences in two of the three groups, we see lower skin fold values of volleyball players, but not significantly lower. These differences of girls in the area of morphological characteristics are derived on the basis of the selection processand the growth and development (height, volume and mass of the body), while the lower values in the subcutaneous adipose tissue of volleyball players can be attributed to the training treatment practicing volleyball. Based on the results of applied congruence of factors extracted, it can be concluded that groups ofgirls do not differ in the structure of the first isolated factors - that define the structure of the morphological space, but there is a difference in the structure of the second and third factors that define the variables of motor abilities and intelligence. It is particularly important to see the difference in the structure of other factors,by age or importance of certain motor variables by which can be seen that the sample of volleyball players in the motor space is far more homogeneous, more clearly defined, with the domination of variables regarding the intensity and duration of excitation and structuring of movement. On the basis of the research on thespecificity of the anthropological area, two groups of girls of school age, in line with the set goals and tasks in which they checked defined hypotheses, a general conclusion is that girls who are in the training program - volleyball players differ significantly in morphology and motor area in respect of girls who are notinvolved in physical activity, while in the intellectual functioning of two groups ofsubjects were not observed statistically significant differences.
35
Mushfieldt, Diego. "Robust facial expression recognition in the presence of rotation and partial occlusion." Thesis, University of Western Cape, 2014. http://hdl.handle.net/11394/3367.
Full textAbstract:
>Magister Scientiae - MScThis research proposes an approach to recognizing facial expressions in the presence of rotations and partial occlusions of the face. The research is in the context of automatic machine translation of South African Sign Language (SASL) to English. The proposed method is able to accurately recognize frontal facial images at an average accuracy of 75%. It also achieves a high recognition accuracy of 70% for faces rotated to 60◦. It was also shown that the method is able to continue to recognize facial expressions even in the presence of full occlusions of the eyes, mouth and left/right sides of the face. The accuracy was as high as 70% for occlusion of some areas. An additional finding was that both the left and the right sides of the face are required for recognition. As an addition, the foundation was laid for a fully automatic facial expression recognition system that can accurately segment frontal or rotated faces in a video sequence.
36
Brown, Dane. "Faster upper body pose recognition and estimation using compute unified device architecture." Thesis, University of Western Cape, 2013. http://hdl.handle.net/11394/3455.
Full textAbstract:
>Magister Scientiae - MScThe SASL project is in the process of developing a machine translation system that can translate fully-fledged phrases between SASL and English in real-time. To-date, several systems have been developed by the project focusing on facial expression, hand shape, hand motion, hand orientation and hand location recognition and estimation. Achmed developed a highly accurate upper body pose recognition and estimation system. The system is capable of recognizing and estimating the location of the arms from a twodimensional video captured from a monocular view at an accuracy of 88%. The system operates at well below real-time speeds. This research aims to investigate the use of optimizations and parallel processing techniques using the CUDA framework on Achmed’s algorithm to achieve real-time upper body pose recognition and estimation. A detailed analysis of Achmed’s algorithm identified potential improvements to the algorithm. Are- implementation of Achmed’s algorithm on the CUDA framework, coupled with these improvements culminated in an enhanced upper body pose recognition and estimation system that operates in real-time with an increased accuracy.
37
Krasovec, Gabriel. "Compréhension du rôle morphogénétique de l'apoptose et de son évolution : apports de l'étude de la métamorphose de Ciona intestinalis (Tunicata) et de Clytia hemisphaerica (Cnidaria)." Electronic Thesis or Diss., Sorbonne université, 2018. http://www.theses.fr/2018SORUS266.
Full textAbstract:
L'apoptose est une mort cellulaire très bien caractérisée d’un point de vue morphologique et biochimique mais dont le rôle morphogénétique a longtemps été restreint à une destruction des structures transitoires ou surnuméraires (Fonction Destructrice de l’Apoptose, FDA). Plus récemment une capacité des cellules apoptotiques à modifier le comportement (migration) ou le destin (prolifération, différenciation, survie) des cellules voisines a été mise en en évidence dans des modèles expérimentaux et des contextes morphogénétiques très divers. Nous avons décidé de regrouper et nommer ces capacités au sein d'une même fonction morphogénétique, la Fonction Constructrice de l'Apoptose (FCA). Afin de mieux comprendre le fonctionnement et l’évolution de la FCA, j'ai utilisé le cadre morphogénétique de la métamorphose, caractérisée par la présence simultanée d’apoptose et de l’ensemble des comportements et destins cellulaires, chez deux organismes éloignés phylogénétiquement, le cnidaire Clytia hemisphaerica et le tunicier Ciona intestinalis. Chez C. hemisphaerica, j’ai identifié et caractérisé dans la larve planula en métamorphose de l’apoptose ectodermique et endodermique, la prolifération et la différenciation des i-cells en nématocytes et la migration de ces derniers. Ces résultats confortent l’utilisation de ce modèle pour étudier la FCA. Chez C. intestinalis, j'ai démontré que la migration des Cellules Germinales Primordiales (PGC) est un exemple de FCA, permettant ainsi une caractérisation moléculaire de cette dernièreApoptosis has been considered as merely required for the removal of supernumerary cells or larval structures by dismantling cells with a characteristic and conserved set of morphological and biochemical features (Destructive Function of Apoptosis, DFA). Accumulating evidences show how apoptotic cells can trigger and modulate other cell behaviors (migration) or cell fates (proliferation, survival, differentiation) during very different morphogenetic events in numbers of animals. These studies led us to define a novel morphogenetic role of apoptosis, hereafter referred as the Constructive Function of Apoptosis (CFA). To investigate the CFA and its evolution in animals, I initiated characterization of CFA during metamorphosis of two distantly related species with a key phylogenetic position, the cnidarian Clytia hemisphaerica, and the tunicate, Ciona intestinalis. In C. hemisphaerica, I have identified and characterized endodermic and ectodermic apoptosis in planula larva. This apoptosis occurred in the larva at the same area and at the same time with the proliferation and differentiation of i-cells and nematocytes migration. All together, these results arguing in favor of planula metamorphosis as an excellent model to study CFA. In C. intestinalis, I have demonstrated that primordial germ cells migration is due to CFA during the tail regression process, leading to the molecular characterization of CFA in this model
38
Mackových, Marek. "Analýza experimentálních EKG." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-241981.
Full textAbstract:
This thesis is focused on the analysis of experimental ECG records drawn up in isolated rabbit hearts and aims to describe changes in EKG caused by ischemia and left ventricular hypertrophy. It consists of a theoretical analysis of the problems in the evaluation of ECG during ischemia and hypertrophy, and describes an experimental ECG recording. Theoretical part is followed by a practical section which describes the method for calculating morphological parameters, followed by ROC analysis to evaluate their suitability for the classification of hypertrophy and at the end is focused on classification.
39
Bellamy, Stephen, and steve bellamy@flinders edu au. "RESOURCE PARTITIONING BETWEEN TWO SYMPATRIC AUSTRALIAN SKINKS, EGERNIA MULTISCUTATA AND EGERNIA WHITII STEPHEN BELLAMY Thesis submitted in total fulfilment of the requirements of the degree of Doctor of Philosophy AUGUST 2006 SCHOOL OF BIOLOGICAL SCIENCES FLINDERS UNIVERSITY, ADELAIDE, SOUTH AUSTRALIA ________________________________________." Flinders University. Biological Sciences, 2007. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20070124.145924.
Full textAbstract:
When species compete for resources, in a stable homogeneous environment, there are two possible outcomes. The first is that one species will out-compete the other and exclude it from the environment. This is known as the competitive exclusion principle. The second is that both species will manage to coexist. Coexistence can only occur if the species niches are differentiated such that interspecific competition is minimised, or eliminated. This outcome is known as resource partitioning.
Two closely related Australian skink species of the Egernia genus, Egernia multiscutata and Egernia whitii, are abundant and sympatric on Wedge Island in South Australias Spencer Gulf. The species are morphologically very similar and appear to have very similar life histories and habitat requirements. Ostensibly, they would compete for limiting resources in this environment.
This thesis is the first investigation into resource partitioning in this previously unstudied model organism. I report the results of multi-faceted investigations into the coexistence of the skinks, E. multiscutata and E. whitii on Wedge Island and the evidence for, and mechanisms of, any facultative resource partitioning between them.
Study methods involved a transect survey of most of Wedge Island to determine the species distributions and any evidence for resource partitioning; a morphological comparison to investigate any potential competitive advantages of either species; a habitat choice experiment to establish retreat-site preferences in the absence of interspecific interference; and, a series of staged dyadic encounter experiments to investigate interspecific competitive interactions.
Resource partitioning was evidenced by differential distributions of the species among substrates containing the elements required for permanent refuge shelters. This partitioning was not mediated by avoidance of particular substrates but by the presence of the opponent species, combined with attraction to suitable substrates. Asymmetries in some morphological characters were found to confer a potential competitive advantage to E. multiscutata in agonistic encounters with E. whitii. Both species were found to have the same refuge site preferences when interference competition was experimentally removed. This result was not concordant with observed resource partitioning in the field and suggests that the habitat choices of both species are modified by the presence of the opponent species. Analyses of staged dyadic encounter experiments showed that E. multiscutata was more likely to gain greater access to a contested habitat resource and more likely to exclude E. whitii from the resource than vice-versa. Nevertheless, the outcome of competitive interactions was not completely deterministic and there was some tolerance of co-habitation. E. multiscutatas competitive advantage was attributable largely to its greater mass and head dimensions relative to snout to vent length. However, differential behavioural responses to the threat of larger opponent size also played an important part in resource partitioning between the species.
40
Láník, Aleš. "Detekce výrobků na pásovém dopravníku." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2008. http://www.nusl.cz/ntk/nusl-235894.
Full textAbstract:
In this master thesis, object's detection in image and tracking these objects in temporal area will be presented. First, theoretical background of the image's preprocessing, image filtration, the foreground extraction, and many others various image's features will be described. Next, design and implementation of detector will be processed. This part of my master thesis containes mainly information about detection of objects on belt conveyer Finally,results, conclusion and many supplementary data such as a photography camera's location will be shown.
41
Cokelaer, François. "Amélioration des ouvertures par chemins pour l'analyse d'images à N dimensions et implémentations optimisées." Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-00952306.
Full textAbstract:
La détection de structures fines et orientées dans une image peut mener à un très large champ d'applications en particulier dans le domaine de l'imagerie médicale, des sciences des matériaux ou de la télédétection. Les ouvertures et fermetures par chemins sont des opérateurs morphologiques utilisant des chemins orientés et flexibles en guise d'éléments structurants. Ils sont utilisés de la même manière que les opérateurs morphologiques utilisant des segments orientés comme éléments structurants mais sont plus efficaces lorsqu'il s'agit de détecter des structures pouvant être localement non rigides. Récemment, une nouvelle implémentation des opérateurs par chemins a été proposée leur permettant d'être appliqués à des images 2D et 3D de manière très efficace. Cependant, cette implémentation est limitée par le fait qu'elle n'est pas robuste au bruit affectant les structures fines. En effet, pour être efficaces, les opérateurs par chemins doivent être suffisamment longs pour pouvoir correspondre à la longueur des structures à détecter et deviennent de ce fait beaucoup plus sensibles au bruit de l'image. La première partie de ces travaux est dédiée à répondre à ce problème en proposant un algorithme robuste permettant de traiter des images 2D et 3D. Nous avons proposé les opérateurs par chemins robustes, utilisant une famille plus grande d'éléments structurants et qui, donnant une longueur L et un paramètre de robustesse G, vont permettre la propagation du chemin à travers des déconnexions plus petites ou égales à G, rendant le paramètre G indépendant de L. Cette simple proposition mènera à une implémentation plus efficace en terme de complexité de calculs et d'utilisation mémoire que l'état de l'art. Les opérateurs développés ont été comparés avec succès avec d'autres méthodes classiques de la détection des structures curvilinéaires de manière qualitative et quantitative. Ces nouveaux opérateurs ont été par la suite intégrés dans une chaîne complète de traitement d'images et de modélisation pour la caractérisation des matériaux composite renforcés avec des fibres de verres. Notre étude nous a ensuite amenés à nous intéresser à des filtres morphologiques récents basés sur la mesure de caractéristiques géodésiques. Ces filtres sont une bonne alternative aux ouvertures par chemins car ils sont très efficaces lorsqu'il s'agit de détecter des structures présentant de fortes tortuosités ce qui est précisément la limitation majeure des ouvertures par chemins. La combinaison de la robustesse locale des ouvertures par chemins robustes et la capacité des filtres par attributs géodésiques à recouvrer les structures tortueuses nous ont permis de proposer un nouvel algorithme, les ouvertures par chemins robustes et sélectives.
42
Huang, Chiao-Wei, and 黃教暐. "Implementation of an Arrhythmia Detection System for Android-based Smartphones by Using the Morphological Features of ECG Signals." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/999qc6.
Full text
43
Chang, Zong-Yi, and 張宗毅. "Implementation of a Myocardial ischemia Detection System for Android-based Smartphones by using the Morphological Features of ECG signals." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/23gp5z.
Full text
44
Lin, Hsin-Hua. "AN INVESTIGATION OF PRESCHOOLERS' PREFERENCES ON MORPHOLOGICAL FEATURES OF MAMMALS." 2004. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-1607200411092400.
Full text
45
Huang, Li-An, and 黃立安. "Development of PC-Based ECG system and Image ECG Features Extraction." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/01214174034474159870.
Full textAbstract:
碩士國立陽明大學
醫學工程研究所
94
Abstract The image electrocardiogram (ECG) display method can give an integral view in temporal evolution and spatial distribution of cardiac signals, and provide 12-lead ECG to enhance the efficacy of differentiation of the signal relativity and variation. In this research, lead II was not only applied to detect P, R, and T wave, but also served as an assistant of localization by the spatial distribution of image ECG. The function of automatic spatial location can facilitate the amateur cardiology doctors understanding the location of waves in image ECG. The automatic locator prevents user from getting lost in image ECG and simultaneously extracts the features of image ECG, which provide user friendly interface and avoid the unpredictable user-dependent factor. It facilitate doctors more easily differentiate the normal and abnormal cardiac signals. In order to discriminate the shape of waves in the image ECG, the cardiac signals can be divided based on the image ECG automatic locator in the future. In this research, the PC-based 12 lead ECG acquisition system also has been developed. This system combines the ECG analog and digital signal processing system. In order to reduce the volume, weight, and noise interference of this system, the system uses battery to provide power and fiber to transmit signals, which also facilitate the convenience and portability in clinical.
46
Liang, Sz-Ying, and 梁思潁. "Wavelet-Based ECG Features Extraction and Noise Reduction." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/11716642464682328078.
Full text
47
Lin, Jun Rong, and 林俊榮. "The study of ECG features extraction and classification." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/60362558851765244178.
Full textAbstract:
碩士中原大學
醫學工程學系
83
For the purpose of real time ECG diagnostic, the paper discusses the method to recognize ECG pattern. The ECG is one of the main cardiac diagnosis tools. The abnormal ECG in the sequential Heart beat is the most difficult to identify, e.g. the data of Holter ECG recording, bedside monitor, or exercise ECG recording. When the training of SOM neural network finished, the output layer would classify pattern. The weighting values of the features vector and the center node would be fixed. We combined the weighting values with features vector using Euler distance equation to pick out the abnormal ECG signal. Using MIT/BIH arrhythmia database. The total of 1150 training samples has been used as training groups. The total of 923 samples has been used as to test the method. The feature of lead II ECG has been automatic extracted. A normalized data is fed to SOM neural network for pattern classification. From the classified pattern of SOM, the weighting value of the center node and features vector are forming a pattern distance equation(minimum Euler distance equation). Then, put in all training samples to normal equation that a interval range of NOR value can be obtained. In this thesis, five different ECG patterns has been tested which are normal(NOR), premature ventricular contraction(PVC), fusion premature ventricular contraction (FUS PVC), right bundle branch block(RBBB) and left bundle branch block(LBBB). To test the method, the study extracted 12 features of ECG. The SOM uses 400 processing elements. The neighborhood radius is 20. The learning cycle is 80 iterations. The learning rate coefficient is 0.5. Using ECG pattern in MIT/BIH database, the system demonstrates more than 98 percent correct classification. For the purpose of labeling the abnormal ECG, the equation can be further reduced to only 8 dominant features. Therefore, the method can be implemented into real time process to screen the ECG data. The method has been tested in screen 14 adult subjects to real
48
Yen, Shao-Yung, and 顏紹雍. "The ECG features detection and arrhythmia classification system." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/36848125095541950811.
Full textAbstract:
碩士元智大學
工業工程與管理學系
95
Automated diagnostic system has become an established component of medical technology. The main concept of the medical technology is an inductive engine that learns the decision characteristics of the diseases and then can be used to diagnose future patients with uncertain diseases states. Electrocardiogram (ECG) is an important tool in diagnosing the condition of the heart. It provides valuable information about the functional aspects of the heart and cardiovascular system. This research develops an algorithm to extract the QRS complex wave and combines the clinical judgment criterion of the cardiac arrhythmia to model a classification system. The system input data is ECG signal and output is the classification of cardiac arrhythmia. The method is forward-backward algorithm that is revised So and Chan method and augments forward and backward searching rules and also deletes lower R amplitude to improve the detection performance. The ECG signals are taken form MIT-BIH arrhythmia database, which are used to classify 4 different arrhythmias for training. There are normal, premature ventricular contraction, ventricular flutter/fibrillation and 2o heart block (Tsipouras, 2005). Regard MIT-BIH arrhythmia database as training data in order to set up the parameters, verifying and testing by real medical ECG data. According to QRS complex extraction and clinical judgment criterion of the cardiac arrhythmia, the proposed approach provided 96.3% accuracy of classification on MIT-BIH database and 90.38% accuracy of classification on empirical medical ECG data.
49
Lee, Wan-Jou, and 李宛柔. "Compressed Domain Biometric Identification Using Two-Lead ECG Features." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/quz75m.
Full textAbstract:
碩士國立交通大學
電機工程學系
104
In wireless telecardiology application, compressed ECG packets are often required for efficient transmission and storage purposes. Compressed ECG data must be decompressed first before applying existing biometric techniques that work on the original signal. In this work, we propose a new method which applies two-lead ECG signals to perform person identification in compressed domain. Incorporation of compressed domain ECG biometric enables faster person identification as it bypasses the full decompression. Compared to previous studies that focus on one limb lead, this study adds precordial lead as another source for person identification. Experiment results show that the combined use of two-lead features can improve the identification accuracy for the arrhythmia patients. First, we apply a preprocessor which converts two-lead 1-D ECG signals to 2-D image matrices and compress them by JPEG2000 image coding standard. Feature relating to ECG morphology were then extracted for indexing person identity by shape and texture content in a known enrollment database. Experiments on public ECG databases demonstrate the validity of the proposed method for biometric identification with an accuracy of 96.70% on both healthy and diseased subjects.
50
Chia, Yuan-Hsun, and 賈元勳. "An ECG Recognition System Using Features from Discrete Wavelet Transform." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/50453996997222074278.
Full textAbstract:
碩士國立中正大學
電機工程研究所
91
Abstract After human is entering the information age, more and more works have been taken over working chance which was replaced by computers. However, it is still our pursuing goal to have the work done even more quickly and accurately. Willem Einthoven discovered galvanometer in 1903 and then implemented that to record the electrical activity of the heart, the electrocardiogram, ECG. From then on, the diagnosis of ECG becomes an important issue in medical. The purpose of this study is to do systematic processing and analysis of the complicated and large quantity of ECG data. We use the wavelet transform to analyze ECG to build an auto-classification and recognition system for ECG. Four classification methods were tested in this study. They are Euclidean Nearest Neighbor method, Linear Discriminant analysis, Back-propagation Neural Networks, and Radial-Basis Function Network. The purpose of these comparisons is intending to look for more quick and accurate methods for ECG analysis. In this way, the users can easily get the embedded information and make judgments more efficiently, and much more medical resources can be saved. The performances of the classifier were evaluated by using half of the waves as training and the other half as testing (intra-data test), as well as using the total-leave-one (cross-validation) test. The best performance was achieved in using Radial-Basis Function Networks in the intra-data test. The recognition rate can be as high as 97.49%, which is comparable to the outstanding methods found in the literature while the computational load is extensively reduced.