Dissertations / Theses on the topic 'Breast region of interest'

Image compression based on Region of Interest (ROI) has been one of the hot topics of interest in image processing. There is not a single widely accepted method for detecting the ROI automatically form an image. To reduce the transmission bandwidth and storage space requirements of gray scale images, an algorithm is suggested for detecting the ROI automatically based on Tsallis entropy method. Tsallis entropy method is used to segment the image into two segments, the ROI and the background. These two segments can then be compressed at different rates, to avoid losing information in the ROI while achieving a good compression. Different approaches of compression based on wavelets and use of various compression methods are also discussed.

Thesis (M.S. in Electrical Engineering)--S.M.U., 2007.
Title from PDF title page (viewed Mar. 18, 2008). Source: Masters Abstracts International, Volume: 45-03, page: 1615. Adviser: Scott C. Douglas. Includes bibliographical references.

In video transmission at low bit rates the challenge is to compress the video with a minimal reduction of the percieved quality. The compression can be adapted to knowledge of which regions in the video sequence are of most interest to the viewer. Region of interest (ROI) video coding uses this information to control the allocation of bits to the background and the ROI. The aim is to increase the quality in the ROI at the expense of the quality in the background. In order for this to occur the typical content of an ROI for a particular application is firstly determined and the actual detection is performed based on this information. The allocation of bits can then be controlled based on the result of the detection.

In this licenciate thesis existing methods to control bit allocation in ROI video coding are investigated. In particular pre-processing methods that are applied independently of the codec or standard. This makes it possible to apply the method directly to the video sequence without modifications to the codec. Three filters are proposed in this thesis based on previous approaches. The spatial filter that only modifies the background within a single frame and the temporal filter that uses information from the previous frame. These two filters are also combined into a spatio-temporal filter. The abilities of these filters to reduce the number of bits necessary to encode the background and to successfully re-allocate these to the ROI are investigated. In addition the computational compexities of the algorithms are analysed.

The theoretical analysis is verified by quantitative tests. These include measuring the quality using both the PSNR of the ROI and the border of the background, as well as subjective tests with human test subjects and an analysis of motion vector statistics.

The qualitative analysis shows that the spatio-temporal filter has a better coding efficiency than the other filters and it successfully re-allocates the bits from the foreground to the background. The spatio-temporal filter gives an improvement in average PSNR in the ROI of more than 1.32 dB or a reduction in bitrate of 31 % compared to the encoding of the original sequence. This result is similar to or slightly better than the spatial filter. However, the spatio-temporal filter has a better performance, since its computational complexity is lower than that of the spatial filter.

Automatic extraction of focused regions from images with low depth-of-field (DOF) is a problem without an efficient solution yet. The capability of extracting focused regions can help to bridge the semantic gap by integrating image regions which are meaningfully relevant and generally do not exhibit uniform visual characteristics. There exist two main difficulties for extracting focused regions from low DOF images using high-frequency based techniques: computational complexity and performance. A novel unsupervised segmentation approach based on ensemble clustering is proposed to extract the focused regions from low DOF images in two stages. The first stage is to cluster image blocks in a joint contrast-energy feature space into three constituent groups. To achieve this, we make use of a normal mixture-based model along with standard expectation-maximization (EM) algorithm at two consecutive levels of block size. To avoid the common problem of local optima experienced in many models, an ensemble EM clustering algorithm is proposed. As a result, relevant blocks, i.e., block-based region-of-interest (ROI), closely conforming to image objects are extracted. In stage two, two different approaches have been developed to extract pixel-based ROI. In the first approach, a binary saliency map is constructed from the relevant blocks at the pixel level, which is based on difference of Gaussian (DOG) and binarization methods. Then, a set of morphological operations is employed to create the pixel-based ROI from the map. Experimental results demonstrate that the proposed approach achieves an average segmentation performance of 91.3% and is computationally 3 times faster than the best existing approach. In the second approach, a minimal graph cut is constructed by using the max-flow method and also by using object/background seeds provided by the ensemble clustering algorithm. Experimental results demonstrate an average segmentation performance of 91.7% and approximately 50% reduction of the average computational time by the proposed colour based approach compared with existing unsupervised approaches.

Notre travail s’inscrit dans le cadre de la biométrie par la rétine. La rétine est la couche sensorielle de l’œil, elle présente une texture riche et unique même chez les jumeaux. Ses propriétés ont fait de la biométrie par la rétine un axe de recherche actif. En effet, de nombreuses méthodes ont été proposées pour les différentes étapes de la méthode biométrique allant du prétraitement de l’image rétinienne à son analyse, en passant par sa caractérisation, afin d’identifier et authentifier un individu. Nous nous intéressons dans ces travaux de thèse, à l’étude, la conception, le développement et l’évaluation d’une nouvelle méthode biométrique basée sur la rétine. Notre première contribution réside dans la conception d’une méthode d’analyse d’image rétinienne saine et pathologique, suivie d’une sélection d’une région d’intérêt autour du disque optique. Cette méthode améliore la qualité de l’image rétinienne et extrait une région d’intérêt la plus stable de la rétine afin de maintenir une densité d’information satisfaisante, pour assurer une meilleure qualité de reconnaissance. Notre deuxième contribution porte sur la proposition d’une nouvelle méthode d’extraction de caractéristiques locales basée sur le descripteur standard SIFT. Elle applique une nouvelle approche reposant sur la suppression des points d’intérêt non informatifs extraits par le descripteur standard SIFT. Cette nouvelle méthode d’extraction des caractéristiques locales réduit le nombre des points d’intérêt redondants tout en maintenant la qualité de la description. Nous avons validé, la méthode biométrique proposée sur différentes bases comprenant des images saines et pathologiques. Les résultats obtenus montrent des performances encourageantes. Ces résultats indiquent, que la méthode que nous avons proposée, localise correctement la région d’intérêt rétinienne. En mode identification, un taux d’identification correcte d’environ 99.8% est atteint. En mode vérification, nous avons obtenu un taux FRR de 0.12% quant aux taux FAR et EER (erreur), ils sont de 0%. L’étude comparative a montré que notre méthode est plus discriminative que d’autres méthodes de l’état de l’art, notamment celles basées sur la segmentation et l’extraction de l’arbre vasculaire
Our work is part of the retina biometrics. The retina is the sensory layer of the eye; it has a rich and unique texture even in twins. Its properties have made the retina biometrics an active research area. Indeed, numerous methods have been proposed for the various stages of the biometric method, from pretreatment of the retinal image to its analysis, through its characterization, in order to identify and authenticate an individual. We are interested in this work in these thesis works, the study, design, development and evaluation of a new biometric method based on the retina. This thesis presents our contributions for each stage of the proposed biometric method. Our first contribution lies in the proposition of a healthy and pathological retinal image analysis method, followed by a selection of a region of interest around the optical disc. This method improves the quality of the retinal image and extracts a more stable region of interest from the retina to maintain a satisfactory information density, to ensure a better quality of recognition. Our second contribution consists in proposing a new method for extracting local characteristics based on the standard SIFT descriptor. It applies a new method based on the removal of non-informative points of interest extracted by the standard SIFT descriptor. This new method of extracting local features reduces the number of redundant points of interest while maintaining the quality of the description. We validated, the proposed biometric method on different bases including healthy and pathological images. This biometric method has yielded encouraging results on healthy and pathological retinal images. The results obtained show encouraging performances. These results indicate that the method we have proposed, correctly locates the retinal region of interest. In identification mode, a correct identification rate of approximately 99.8% is reached. In verification mode, we obtained 0.12% as FRR error rate and 0% for the FAR and EER error rates. The comparative study showed that our method is more discriminative than other state-of-the-art methods, especially those based on segmentation and extraction of the vascular tree

Video is the most demanding modality from the viewpoints of bandwidth, computational complexity, and resolution. Thus, there has been limited progress in the field of mobile video technology. In the research, the focus is on elastic wireless video technology, and its adaptation to diagnostic application requirements in real-time clinical assessment. It is important and timely to apply wireless video technology to real-time remote diagnosis of emergent medical events. This premise comes from initial successes in telehealth based on wired networks. The enablement of mobility (for the physician and/or the patient) by wireless communication will be a next major step, but this advance will depend on definitive and compelling demonstrations of reliability. Thus, an important goal of the research is to develop a complete methodology that will be embraced by physicians. Acute pediatric asthma has been identified as a domain where this new capability will be highly welcome. The research uses flexible and interactive algorithms for Region-of-Interest (ROI) processing. ROI processing is a useful approach to achieve the optimal balance in the quality-bandwidth tradeoff characteristic of visual communication services. The notion of ROI has been traditionally used mostly for foreground-background separation in scene rendering and manipulation, and only more recently for variably quality compression. Even when the latter goal is considered, quality criteria have been ad-hoc and at best useful for video conferencing, given that the medical domain has its own fidelity criteria. The research thus focuses on the design of an elastic ROI-based compression paradigm with medical diagnosis as a central criterion. The research describes the methodology to achieve elasticity through rate control algorithms at the encoder. An elastic non-parametric approach is proposed that uses a priori user-specified video quality information, quantifies this information, and incorporates this into the encoder in the form of region-quality mappings. This method is compared to a parametric bit allocation approach that is based on region-features and a set of tuning weights. A number of videos of actual patients were filmed and used as the video database for the developed algorithms. In testing the elastic non-parametric and parametric algorithms, both objective measures in the form of Peak Signal to Noise Ratio (PSNR), and subjective evaluations were used. Thus, in this work, the focus is on domain relevance of the algorithms developed, as opposed to network related issues such as packet losses. This is justified in that these may have broader value with other applications, and continuation of this work will include realistic network conditions. To summarize, the research shows the usefulness of ROI processing as a means of achieving a gain (in a bits per pixel sense) over uniform compression at the same bitrate. It also shows how quantifying a notion of functionally lossless video quality diagnostically lossless video quality in a video-based telehealth system, in a bits per pixel sense is useful from an applications and bitrate perspective. Finally, a combination of these two concepts is advantageous i.e. diagnostically lossless ROI video quality is achievable over bitrate limited channels.

While the games industry grows, the need for visually appealing graphics increase. This drives the demand for new hardware and the development of new techniques forward. With the latest generation of 3D graphic APIs the new rendering pipeline technique tessellation was announced. With each generation of games getting more advanced, the demand for highly detailed models increase. This leads to a higher workload for the GPU. The purpose of this thesis is to research the fi eld of tessellation and develop a prototype to optimize the tessellation pipeline. The prototype is designed to help reduce the number of generated triangles by dividing the mesh into regions, each region with its own tessellation factor. The prototype implementation supports both manual and automatic generation of these regions. A new fi le format was developed to support the region data. The implementation was split into three parts; one Python based Maya plug-in used for preparing the model for exporting, one exporter for Maya that generated the output fi le, and one viewer application capable of rendering the resulting mesh. The geometry output of the proposed technique was evaluated by comparing it to uniformly tessellated reference mesh geometry. Measurements show that the proposed technique is capable of reducing the face count with minor or maintained correlation to the reference geometry.
Medans spelindustrin växer ökar behovet av visuellt tilltalande grafik. Detta driver utvecklingen av hårdvara och nya tekniker framåt. Med den senaste generationens 3D grafik API kom renderingssteget tesselering. Eftersom varje generation av spel blir mer avancerat ökar efterfrågan på detaljerade modeller. Detta leder till en högre arbetsbörda för GPUn. Syftet med denna avhandling är att undersöka tesselering och utveckla en prototyp för att optimera tesseleringspipelinen. Prototypen är utformad för att hjälpa till att minska antalet genererade trianglar genom att dela upp figuren i regioner, varje region med egen tesseleringsfaktor. Prototypen stödjer både manuell och automatisk generering av dessa regioner, ett nytt filformat utvecklades för att stödja dessa. Prototypen delades upp i tre delar, ett Python baserat Maya plug-in som används för att förbereda modellen för export, en Maya exportör som genererar filerna, och ett visningsprogram som kan rendera den färdiga figuren. Figuren från den föreslagna tekniken utvärderades genom att jämföra den med motsvarande figur med universal tesseleringsfaktor. Mätningar visar att den föreslagna tekniken klarar att reducera antalet trianglar med låg felmarginal.

This thesis describes research work undertaken in the field of image mining. More specifically, the research work is directed at image classification according to the nature of a particular Region Of Interest (ROI) that appears across a given image set. Four approaches are described in the context of the classification of medical images. The first is founded on the extraction of a ROI signature using the Hough transform, but using a polygonal approximation of the ROI boundary. The second approach is founded on a weighted subgraph mining technique whereby the ROI is represented using a quad-tree structure which allows the application of a weighted subgraph mining technique to identify feature vectors representing these ROIs; these can then be used as the foundation with which to build a classifier. The third uses an efficient mechanism for determining Zernike moments as a feature extractor, which are then translated into feature vectors to which a classification process can be applied. The fourth is founded on a time series analysis technique whereby the ROI is represented as a pseudo time series which can then be used as the foundation for a Case Based Reasoner. The presented evaluation is directed at MRI brain scan data where the classification is focused on the corpus callosum, a distinctive ROI in such data. For evaluation purposes three scenarios are considered: distinguishing between musicians and non-musicians, left handedness and right handedness, and epilepsy patient screening.

Panoramic virtual reality is an emerging technology that has recently gained the attention of both the research community and regular consumers. It allows the users to immerse themselves in omnidirectional videos with the help of a virtual reality headset : thanks to an increasing amount of affordable head-mounted-displays, any recent smartphone can offer a decent panoramic virtual reality experience. However since omnidirectional videos are videos with a large field-of-view that covers the entire sphere around the camera, they require large resolutions and thus high bitrates. This master degree project conducted at RE’FLEKT GmbH is an exploratory work that seeks to reduce the panoramic video bitrate. Because of the nature of omnidirectional videos, the user can only see a subpart of each video frame, and thus some zones of the video can attract more attention than others. The purpose of this study is to introduce the concept of region-of-interest encoding in panoramic VR. The main contribution is a method to encode panoramic videos in an H.264 video format stream with a space-variant level of details depending on the zones that attract the most the viewers’ interest. First, the region-of-interest are detected through a head-tracking module combined with a Gaussian attention model. Then, the reference video is encoded with the open source x264 encoder, with a quantization step adjusted to the region-of-interest information. The International Telecommunications Union standard subjective tests show that this method can perform better than classic H.264 encoding only in specific cases.
Panoramisk virtuell verklighet (VR) är en kommande teknik som nyligen har mött intresse från forskarsamhället och vanliga konsumenter. Det gör det möjligt för användarna att fördjupa sig i videor upptagna från flera riktningar, med hjälp av ett VR-headset : tack vare ett växande antal billiga och huvudburna bildskärmar, erbjuder alla nya smarttelefoner en passande panoramisk VR-erfarenhet. Men på grund av den breda synvinkeln i flerriktade media behöver videor med 360 graders synfält stor upplösning och därför höga bithastigheter. Detta masterexamensarbete som utförts på RE’FLEKT GmbH är ett utforskande arbete som strävar efter att reducera panoramabildens bithastighet. I flerriktade videoklipp kan användaren bara se en del av varje bildruta, härigenom får somliga zoner mer uppmärksamhet än andra. Syftet med denna studie är att introducera begreppet region-av-intresse (ROI) kodning i panoramisk VR. Huvudbidraget är en metod för att koda panoramisk video i en H.264-ström med en varierande nivå av detaljer som beror på de zoner som får mest av tittarnas intresse. Först detekteras ROI genom en huvudspårningsmodul kombinerad med en gaussisk uppmärksamhetsmodell. Därefter kodas referensvideoen med x264-kodaren (öppen källkod) med hjälp av ROI-informationen. ITU-standardens subjektiva test visar att den här metoden kan fungera bättre än klassisk H.264-kodning i enskilda fall.

El trastorno por déficit de atención e hiperactividad (TDAH) es un trastorno del neurodesarrollo caracterizado por síntomas de inatención, hiperactividad e impulsividad. Los modelos clásicos acerca de la neuroanatomía del trastorno apuntan a alteraciones en los circuitos fronto-estriado-cerebelares. Los estudios de neuroimagen estructural apoyan parcialmente estos modelos. Sin embargo, casi todos estos estudios se basan en el análisis de regiones seleccionadas a priori (procedimiento que se conoce como ROI, acrónimo inglés de regiones de interés: "region of interest"). Estudios más recientes basados en aproximaciones globales apuntan a que las alteraciones estructurales no se limitan a los circuitos fronto-estriado-cerebelares, sino que también afectan las regiones temporales, parietales y cinguladas.
El objetivo de la presente tesis es el de redefinir y aplicar dos métodos de análisis estructural complementarios para identificar los circuitos cerebrales alterados en el TDAH así como para relacionar dichos circuitos con los diferentes subtipos clínicos. Para tal fin, presentaremos y discutiremos dos estudios de resonancia magnética estructural (Carmona et al. 2005; Tremols et al. 2008). Estos dos estudios representan una novedad y mejora de estudios de TDAH previos, por dos razones principales: a) la aplicación por primera vez un estudios basado en la morfometría de vóxeles para comparar el cerebro de niños con TDAH con el cerebro de niños controles no relacionados familiarmente; b) el diseño e implementación de un nuevo método, fácil de aplicar, de segmentación manual del núcleo caudado.
Los resultados confirman los datos obtenidos en estudios previos acerca de menor volumen cerebral en niños con TDAH, y localizan esta reducción en determinadas regiones de sustancia gris. A parte de confirmar las alteraciones fronto-estriado-cerebelares hayamos reducciones en áreas parietales, cingulares y temporales. En concreto observamos decrementos volumétricos de sustancia gris en la corteza frontal inferior, el estriado dorsal, la corteza parietal inferior y la corteza cingulada posterior, regiones clásicamente relacionadas con problemas de inhibición, deficits de memoria de trabajo y alteraciones en tareas de atención visuoespacial, respectivamente. También observamos reducciones volumétricas en áreas típicamente emocionales, como la corteza orbitofrontal, el estriado ventral y las estructurales temporales mediales deficits que podrían explicar las disfunciones motivacionales así como las alteraciones en el procesamiento del refuerzo. Curiosamente, las reducciones de sustancia gris en áreas relacionadas con el procesamiento emocional son más pronunciadas en el subtipo hiperactivo-impulsivo, algo menos en el subtipo combinado y casi inexistentes en el subtipo inatento. Esta diferente afectación en función de los subtipos va en la línea de teorías neuroanatómicas actuales acerca del TDAH (Castellanos and Tannock 2002). También observamos déficits de sustancia gris en áreas sensorio-motoras (específicamente en la corteza perirrolándica y el área motora suplementaria), y en el cerebelo. Por un lado, los déficits en áreas sensorio-motoras probablemente reflejan los problemas de psicomotricidad fina que presentan muchos de los niños con TDAH. Sin embargo, el hecho de que estas reducciones sean especialmente prominentes en los subtipos combinado e inatento, sugieren la posibilidad de que estas alteraciones estén especialmente relacionadas con los déficits atencionales. En base a esto, hipotetizamos que las alteraciones en estas regiones producirían un déficit para integrar y actualizar la información procedente del mundo exterior y, a su vez darían lugar a un sesgo a favor del procesamiento de los estados internos resultando en inatención. Por otro lado, las reducciones cerebelares (extensamente observadas en la literatura del TDAH) parecen están relacionadas con los déficits cognitivos, los afectivos y los emocionales. Creemos que la implicación del cerebelo en estas disfunciones estaría vehiculada por el papel de esta estructural como moduladora del flujo de información entre los circuitos fronto-estriatales. Finalmente nuestros hallazgos son los primeros en demostrar alteraciones diferenciales en la cabeza y el cuerpo del núcleo caudado en el TDAH. Esta desigual implicación de las diferentes partes del núcleo caudado explicaría en parte la heterogeneidad de los estudios previos.
Como conclusión, las reducciones volumétricas de sustancia gris en áreas cognitivas y emocionales apoyan la implicación de disfunciones en los circuitos fronto-estriatales llamados cool (cognitivos) y hot (emocionales) respectivamente. Hasta la fecha este es el primer estudio neuroanatómico que apoya la existencia de disfunciones tanto cognitvas como emocionales en niños con TDAH. Nuestros hallazgos constituyen la primera evidencia neuroanatómica a favor de los modelos de doble ruta porpuestos por Sonuga-Barke (Sonuga- Barke 2002; Sonuga-Barke 2003).
REFERENCIAS:
1. Tremols V, Bielsa A, Soliva JC, Raheb C, Carmona S, Tomas J, et al. (2008): Differential abnormalities of the head and body of the caudate nucleus in attention deficit-hyperactivity disorder. Psychiatry Res. 163:270-278.
2. Carmona S, Vilarroya O, Bielsa A, Tremols V, Soliva JC, Rovira M, et al. (2005): Global and regional gray matter reductions in ADHD: a voxel-based morphometric study. Neurosci Lett. 389:88-93.
3. Castellanos FX, Tannock R (2002): Neuroscience of attention-deficit/hyperactivity disorder: the search for endophenotypes. Nat Rev Neurosci. 3:617-628.
4. Sonuga-Barke EJ (2003): The dual pathway model of AD/HD: an elaboration of neuro-developmental characteristics. Neurosci Biobehav Rev. 27:593-604.
5. Sonuga-Barke EJ (2002): Psychological heterogeneity in AD/HD--a dual pathway model of behaviour and cognition. Behav Brain Res. 130:29-36.
Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disease characterized by symptoms of inattention, hyperactivity and impulsivity. Data from different studies point to ADHD abnormalities in fronto-striatal circuits. Structural neuroimaging studies partially support fronto-striatal abnormalities and suggest an important role of the cerebellum. However, nearly all these studies are based on the analysis of apriori selected regions of interest (known as ROI approaches). Recent studies, using more global approaches, found that ADHD structural abnormalities were not limited to fronto-striatal-cerebellar circuits, but also affect temporal, parietal and cingulate regions.
The aim of the present dissertation is to refine and apply two complementary methods of structural neuroimaging, in order to identify the brain circuits altered in
ADHD and relate them to different clinical ADHD subtypes and to known ADHD neuropsychological deficits. For that purpose, two structural MRI studies will be presented and discussed (Carmona et al. 2005; Tremols et al. 2008). The differential contributions of these studies, which represent a novelty and an improvement of previous ADHD studies, are: a) the application for the first time of
voxel-based morphometry analysis to compare ADHD children with non family related control children; b) the design and application of a new, easy to apply, manual method of caudate nucleus segmentation.
The results confirm previous findings about smaller brain volume in ADHD children, and refine this reduction by attributing it to grey matter (GM) volume. We also confirm abnormalities in fronto-striatal-cerebellar circuits as well as in parietal, cingulate and temporal regions. Specifically, we observed reductions in inferior frontal cortex, dorsal striatum, inferior parietal cortex and posterior cingulate cortex; thus explaining inhibition problems, spatial working memory deficits and visuospatial attentional alterations. We also observed GM volume reductions in emotionally driven areas such as orbitofrontal cortex, ventral striatum and middle temporal structures; thus accounting for dysfunctional delayed reward and motivational deficits. Interestingly, GM volume reductions, related to emotional processes are more prominent in H-I subtype, more preserved in combined subtypes, and relatively undisrupted in inattentive subtypes, which is in agreement with previous ADHD theories (Castellanos and Tannock 2002). We have also found GM deficits in "sensori-motor" areas (specifically in perirolandic cortex and supplementary motor area), and in the cerebellum. On the one hand, deficits in sensori-motor areas probably reflect problems in fine motor coordination. However, the fact that these reductions are especially prominent in combined and inattentive subtypes brings up the possibility that they may be related to attentional dysfunctions.
I hypothesized that deficits in these regions may produce a deficit when integrating and updating information from the external world and, in turn, produce a bias toward internal world focusing, thus, resulting in inattention. On the other hand, cerebellar reductions (which are extensively reported in ADHD literature) seem to be related to all cognitive, affective and sensorimotor deficits. The implication of cerebellum in all these dysfunctions may arise from its role as a modulator of the flow of information between fronto-strital circuits. Finally, our findings are also the first to show caudate head and body differential abnormalities in ADHD, which explain previous heterogeneous results, providing a new and reliable method to study striatal structures.
As a conclusion, GM volume reductions in emotional and cognitive areas support the implication of both hot (emotional) and cool (cognitive) functions, which agrees with most neuropsychological accounts of ADHD. To our knowledge this is the first time that a neuroanatomical study provides support for the existence of both cognitive and emotional dysfunctions in ADHD children. If these findings are replicated, they will constitute critical evidence for Sonuga-Barke's theory (Sonuga- Barke 2002; Sonuga-Barke 2003) about the dual route model.
REFERENCIAS:
1. Tremols V, Bielsa A, Soliva JC, Raheb C, Carmona S, Tomas J, et al. (2008): Differential abnormalities of the head and body of the caudate nucleus in attention deficit-hyperactivity disorder. Psychiatry Res. 163:270-278.
2. Carmona S, Vilarroya O, Bielsa A, Tremols V, Soliva JC, Rovira M, et al. (2005): Global and regional gray matter reductions in ADHD: a voxel-based morphometric study. Neurosci Lett. 389:88-93.
3. Castellanos FX, Tannock R (2002): Neuroscience of attention-deficit/hyperactivity disorder: the search for endophenotypes. Nat Rev Neurosci. 3:617-628.
5. Sonuga-Barke EJ (2003): The dual pathway model of AD/HD: an elaboration of neuro-developmental characteristics. Neurosci Biobehav Rev. 27:593-604.
6. Sonuga-Barke EJ (2002): Psychological heterogeneity in AD/HD--a dual pathway model of behaviour and cognition. Behav Brain Res. 130:29-36.

This study examines the dynamic interaction between housing prices, stock prices and the repo rate in the Stockholm region by using the Johansen tests for cointegration. Several studies have been done on this topic, but the results are mixed across the world, and not many have been done in Scandinavia. This study contributes to the literature by examining eleven years of monthly data for the housing prices in the Stockholm region. We find evidence of a long-run relationship between housing prices, stock prices and the interest rate. There is a negative relationship between housing prices and the interest rate as well as between stock prices and the interest rate, but a positive relationship between housing prices and stock prices.  However, the results are somewhat sensitive to model specification and therefore further studies on the topic are encouraged.

The objective of this thesis is to carry out a survival analysis for patients with breast cancer. Using data from the Nanakaly and Hewa hospitals in the cities of Erbil and Suleimaniah, respectively, cases where there is hidden censoring on survival time were investigated. The aim of this study was to identify the main risk factors and quantify the overall risk for breast cancer. We developed a new Markov chain-based method for generating survival curves and hazard functions. In particular we adjusted the Kaplan Meier analysis to find a survival curve with hidden censoring of the data, and also estimated a survival function from the biased one obtained directly from the data by generating new models in two cases; with and without censoring. To ensure the validity of the suggested model we considered different simulation techniques applied to the Nanakaly data. Because of the availability of a good survival function, we chose to work with a German data set. As a result we conclude that our model performs well in many circumstances, and its predictions, even when less accurate, are always an improvement on considering the apparent survival curves from the unadjusted data. For the data from Nanakaly hospital, the only variable we had to consider was age at diagnosis and the survival results showed that this was a significant variable. With far more detailed reports available for Hewa hospital, we were able to identify estrogen abundance, smoking habits and tumour grade, as having a statistically significant impact on the incidence of breast cancer. On the other hand, when analysing the Nanakaly and Hewa data for comparison with German data, in all three cases the survival curve is greater among younger patients. The suggested models may be verified using cross validation or by using new data. Finally, we note that it would be preferable to have accurate data to applying our methods to imperfect data. Therefore we established both a general and a specific flowchart to collect the data in the future. Encouraging the implementation of the recommended procedures might serve to obtain the data needed to develop a more comprehensive understanding of breast cancer in Kurdistan.

Mammographic techniques used for screening programmes need to be of the highest quality; hence, the need of a good phantom to mimic breast response to radiation. The phantom materials must be sensitive to small changes in the mammography system and provide a means of evaluating the absorbed dose to the breast. These materials have to provide the same attenuation properties as the real tissues being simulated, for the radiation modalities being investigated. Cross-linked hydrophilic copolymers have the potential to be good phantom materials for the breast as their elemental compositions are similar to soft tissue. Two types of hydrophilic copolymer materials used in this study were designated as ED1S and ED4C. They were made from a certain proportionate mixture of methyl methacrylate and vinyl pyrrolidone. The physical properties of the materials such as liquid uptake and dimensional changes in hydration and dehydration processes were studied. The equilibrium water content of ED1S and ED4C fully hydrated in water was 55% and 70% respectively. The samples underwent distortion when dehydrated and a volume approximation formula for the dehydrated samples was derived. The linear attenuation coefficient and the mass attenuation coefficient of the hydrophilic copolymer materials at photon energies in the mammographic energy region were determined. Both a single beam transmission method and a photon transmission tomography method were used. The results were compared with XCOM calculated attenuation coefficients of water and average breasts using the elemental composition found in the literature. It was found that the mass attenuation coefficient of dry hydrophilic copolymer samples closely fit the XCOM calculated old-age breast (Breast 3) and samples fully hydrated in water fit the calculated young-age breast (Breast 1). Measurements were also carried out to determine the linear attenuation coefficient of normal and abnormal breast tissues at four photon energies in the mammographic energy region. The values found were in good accord with calculated average breast values. However, more studies need to be done as only three samples were used. The electron density of the hydrophilic copolymer materials was determined by using the Compton scattering technique. The electron density for dry ED1S sample was (3.1 +/- 0.4) x 1023 electrons per cm3 and for dry ED4C was (4.4 +/- 0.4) x 1023 electrons per cm3.

As there is a rapid growth in the field of wireless communications, the demand for various multimedia services is also increasing. The data that is being transmitted suffers from distortions through source encoding and transmission over errorprone channels. Due to these errors, the quality of the content is degraded. There is a need for service providers to provide certain Quality of Experience (QoE) to the end user. Several methods are being developed by network providers for better QoE.The human tendency mainly focuses on distortions in the Region of Interest(ROI) which are perceived to be more annoying compared to the Background(BG). With this as a base, the main aim of this thesis is to get an accurate prediction quality metric to measure the quality of the image over ROI and the BG independently. Reduced Reference Image Quality Assessment (RRIQA), a reduced reference image quality assessment metric, is chosen for this purpose. In this method, only partial information about the reference image is available to assess the quality. The quality metric is measured independently over ROI and BG. Finally the metric estimated over ROI and BG are pooled together to get aROI aware metric to predict the Mean Opinion Score (MOS) of the image.In this thesis, an ROI aware quality metric is used to measure the quality of distorted images that are generated using a wireless channel. The MOS of distorted images are obtained. Finally, the obtained MOS are validated with the MOS obtained from a database [1].It is observed that the proposed image quality assessment method provides better results compared to the traditional approach. It also gives a better performance over a wide variety of distortions. The obtained results show that the impairments in ROI are perceived to be more annoying when compared to the BG.

Satellite formation missions allow for scientific measurement opportunities that are only otherwise possible with the use of unrealistically large satellites. This work applies the Evolutionary Algorithm (EA), Differential Evolution (DE), to a 4-satellite mission design that borrows heavily from the mission specifications for Phase 1 of NASA's Magnetospheric Multi-Scale Mission (MMS). This mission specifies goals for formation "quality" and size over the arc when scientific measurements are to be taken known as the Region of Interest (ROI). To apply DE to this problem a novel definition of fitness is developed and tailored to trajectory problems of the parameter scales of this mission. This method uses numerical integration of evolved initial conditions for trajectory determination. This approach allows for the inclusion of gravitational perturbations without altering the method. Here, the J2 oblateness correction is considered but other inclusions such as solar radiation pressure and other gravitational bodies are readily possible by amending the governing equations of integration which are stored outside of the method and called only during evaluation. A set of three launch conditions is evaluated using this method. Due to computational limitation, the design is restricted to only single-impulse maneuvers at launch and the ROI is initially restricted but then expanded through a process known here as "staging". The ROIs of tests are expanded until they fail to meet performance criteria; no result was able to stage to the full MMS specified $\pm20^\circ$ ROI but this is a result of the single-impulse restriction. The number of orbits a launch condition is able to meet performance criteria is also investigated. Revolutions considered and the ROIs therein contained are staged to investigate if the method is able to handle this additional problem space. Evidence of suitable formation trajectories found by this method is here presented.

17q23 amplicon is one of the many chromosomal regions that undergo amplification in breast tumors. Such amplicons harbor proto-oncogenes that may be overexpressed due to gene amplifications. Copy number analysis in breast cancer cell lines and breast tumors identified several independently amplified regions within the 17q23 amplicon, suggesting that a number of genes are selected for amplification as they may independently contribute to tumor formation and progression. To characterize distinct amplicons on 17q23 and localize putative oncogenes, various studies are done on this region. In order to better understand the role of 17q23 amplification in breast cancer, characterizing unidentified genes or ESTs (Expressed Sequence Tags) on the 17q23 amplicon is crucial. In this study, in silico analysis of human (H.sapiens), chimpanzee (P.troglodytes), and mouse (M.musculus) genomes were performed to examine sequence homology between these 3 species for the purpose of identifying novel genes. The objective of this study was to analyze a 50 kb region between TBX2 and TBX4 genes and characterize the EST T02811 located on that region. Analysis and comparisons of these three genomes were established based on genomic sequences and availability of ESTs with gene prediction programs (BLAST, Pipmaker, Vista, GENSCAN etc.). Based on our results, we prepared a homology map between these 3 species, including positions of ESTs that may indicate novel genes. In this 50 kb region, we found in silico and experimantal evidence for the presence of an unidentified gene. We managed to extend the 313 bp EST T02811 size to 1423 bp which we think is as of yet incomplete. Further studies are needed to characterize this novel gene as a potential oncogene candidate. Characterizing the roles of such candidate oncogenes in amplicons will provide a better understanding of genomic amplicon regions and their roles in tumorigenesis.

Despite extensive research, the pathways of breast cancer development remain largely unknown. Identification of key genetic alterations, particularly at early stages of the disease, are central to elucidating the development of the disease.;Analyses for abnormal forms of the oestrogen receptor (ER) were performed to determine if they may be functionally important in the evolution of breast cancer. Forty four mammographically detected, node negative, 15mm of less, moderately or well differentiated, invasive carcinomas were screened b RT-PCR and single stranded conformational Polymorphism analysis, identifying variant forms of exon 3, 5 and 7 in addition to 3 missense mutations. ER splice variants were detected in 15/44 tumours and included exon 5 (2/44), exon 3 (4/44) and exon 7 (13/44). 10/37 grade I and II tumours had variants compared with 5/7 grade III tumours. In addition, 11/39 ER+ and either progesterone (PgR)+ or PgR- tumours had variants compared with 4/5 ER-/PgR-tumours.;Pure populations of tumour cells were microdissected from well defined groups of breast lesions including ductal carcinoma in situ (DCIA), tubular carcinomas, and a similar tumour group screened for variant ERs, and analysed for alterations to polymorphic microsatellite sequences within, and flanking the ER gene (6q25.1-27) itself. This enabled evaluation of loss of heterozygosity (LOH) indicating the presence of tumour suppressor genes, and microsatellite instability (MI) indicative of a mutator phenotype in colorectal cancers.;Frequent LOH, apart from the M6P/IGF2R locus, was observed for all types and grades of disease studied; identifying loss in this region as an early event involved in breast development/progression. In comparison, MI at multiple loci and LOH at the M6P/IGF2R were only found in high grade DCIS. LOH at this chromosomal interval in all types and grade of disease suggests inactivation of other as of yet uncharacterised tumour suppressor genes mapped on chromosome 6q25.1-27.

Abstract Minimally invasive surgery (MIS) techniques have seen rapid growth as methods for improved operational procedures. The main technology of MIS is based on image guided surgery (IGS) devices, namely surgical navigators, surgical robotics and image scanners. With their widespread use in various fields of surgery, methods and tools that may be used routinely in the hospital setting for “real world” assessment of the accuracy of these devices are lacking. In this thesis the concept of accuracy testing was developed to meet the needs of quality assurance of navigators and robots in a hospital environment. Thus, accuracy was defined as the difference between actual and measured distances from an origin, also including determination of directional accuracy within a specific volume. Two precision engineered accuracy assessment phantoms with assessment protocols were developed as advanced materials and methods for the community. The phantoms were designed to include a common region of surgical interest (ROSI) that was determined to roughly mimic the size of the human head. These tools and methods were utilized in accuracy assessment of two commercial navigators, both enabling the two most widely used tracking modalities, namely the optical tracking system (OTS) and the electromagnetic tracking system (EMTS). Also a study of the accuracy and repeatability of a prototype surgical interactive robot (SIRO) was done. Finally, the phantoms were utilized in spatial accuracy assessment of a commercial surgical 3D CT scanner, the O-Arm. The experimental results indicate that the proposed definitions, tools and methods fulfill the requirements of quality assurance of IGS devices in the hospital setting. The OTS and EMTS tracking modalities were nearly identical in overall accuracy but had unique error trends. Also, the accuracy of the prototype robot SIRO was in the range recommended in the IGS community. Finally, the image quality of the O-Arm could be analyzed using the developed phantoms. Based on the accuracy assessment results, suggestions were made when setting up each IGS device for surgical procedures and for new applications in minimally invasive surgery
Tiivistelmä Mini-invasiivisen eli täsmäkirurgian tekniikoita ja teknologioita on alettu hyödyntää viime aikoina yhä enemmän. Tavoitteena on ollut parantaa kirurgisten operaatioiden tarkkuutta ja turvallisuutta. Täsmäkirurgiassa käytetyt teknologiat pohjautuvat kuvaohjattuihin kirurgisiin paikannuslaitteisiin. Kuvaohjattuihin laitteisiin kuuluvat navigaattorit, kirurgiset robotit ja kuvantalaitteet. Näiden laitteistojen kehittyminen on mahdollistanut tekniikoiden hyödyntämisen monialaisessa kirurgiassa. Paikannuslaitteistojen ja robottien yleistyminen on kuitenkin nostanut sairaaloissa esiin yleisen ongelman paikannustarkkuuden määrittämisessä käytännön olosuhteissa. Tässä väitöskirjassa esitetään kirurgisten yksiköiden käyttöön menetelmä sekä kaksi uutta fantomia ja protokollaa käytössä olevien paikannuslaitteistojen tarkkuuden määrittämiseen. Fantomit suunniteltiin sisältämään ennalta määritetty kirurginen kohdealue, mikä rajattiin käsittämään ihmisen kallon tilavuus. Fantomeita ja protokollaa hyödynnettiin kahden kaupallisen paikannuslaitteen tarkkuuden määrityksessä. Navigaattorit käyttivät optiseen ja elektromagneettiseen paikannukseen perustuvaa tekniikkaa. Lisäksi työssä kehitetyillä menetelmillä tutkittiin prototyyppivaiheessa olevan kirurgisen robotin paikannus- ja toistotarkkuutta sekä tietokonetomografialaitteen O-kaaren kuvan tarkkuuden määritystä. Kokeellisten tulosten perusteella työssä kehitetyt fantomit ja protokollat ovat luotettavia ja tarkkoja menetelmiä kirurgisten paikannuslaitteistojen tarkkuuden määrittämiseen sairaalaoloissa. Kirurgisten navigaattoreiden tarkkuuden määritystulokset osoittivat optisen ja elektromagneettisen paikannustekniikan olevan lähes yhtä tarkkoja. Prototyyppirobotin tarkkuus oli tulosten perusteella kirjallisuudessa esitettyjen suosituksien mukainen. Lisäksi O-kaaren kuvanlaatua voitiin tutkia kehitetyillä fantomeilla. Tarkkuudenmääritystulosten perusteella työssä ehdotetaan menetelmiä laitteistojen optimaalisesta käytöstä leikkaussalissa sekä laajennetaan niiden käyttömahdollisuuksia. Tuloksia voidaan hyödyntää myös paikannuslaitteistojen kehittämistyössä

Thesis (M.A.)--University of Cincinnati, 2006.
Title from electronic thesis title page (viewed Aug. 31, 2007). Includes abstract. Keywords: Episodic memory; Child; Functional magnetic resonance imaging (fMRI). Includes bibliographical references.

Includes abstract.
Includes bibliographical references (leaves 140-144).
Automated microscopy for the detection of tuberculosis (TB) in sputum smears seeks to address the strain on technicians in busy TB laboratories and to achieve faster diagnosis in countries with a heavy TB burden. As a step in the development of an automated microscope, the project described here was concerned with microscope auto-positioning; this primarily involves generating a point of reference on a slide, which can be used to automatically bring desired fields on the slide to the field-of-view of the microscope for re-examination. The study was carried out using a conventional microscope and Ziehl- Neelsen (ZN) stained sputum smear slides. All images were captured at 40x magnification. A digital replication, the virtual slide map, of an actual slide was constructed by combining the manually acquired images of the different fields of the slide. The geometric hashing scheme was found to be suitable for auto-stitching a large number of images (over 300 images) to form a virtual slide map. An object recognition algorithm, which was also based on the geometric hashing technique, was used to localise a query image (the current field-of-view) on the virtual slide map. This localised field-of-view then served as the point of reference. The true positive (correct localisation of a query image on the virtual slide map) rate achieved by the algorithm was above 88% even for noisy query images captured at slide orientations up to 26°. The image registration error, computed as the average mean square error, was less than 14 pixel2 (corresponding to 1.02 μm2 and 0.001% error in an image measuring 1030 x 1300 pixels) corresponding to a root mean square registration error of 3.7 pixels. Superior image registration accuracy was obtained at the expense of time using the scale invariant feature transform (SIFT), with a image registration error of 1 pixel2 (0.07 μm2). The object recognition algorithm is inherently robust to changes in slide orientation and placement, which are likely to occur in practice as it is impossible to place the slide in exactly the same position on the microscope at different times. Moreover, the algorithm showed high tolerance to illumination changes and robustness to noise.

A new fast and progressive set-partitioning image compression parallel algorithm with Region Of Interest (ROI) which outputs an embedded bit oriented rate-distortion optimized stream and addresses very low bit rate compression is presented.User defined variable packet sizes make it suitable for the implementation of any communications protocols, either underwater or in any other scenario, while remaining competitive with current state-of-the-art compressors at higher bit rates.A parallel algorithm for the Discrete Wavelet Transform (DWT) based on the lifting scheme is also presented and it is shown to be optimal in the sense that no other implementation may be faster if memory saturation is achieved.The best ordering for the significant and refinement bits of the transform coefficients is derived, using the Mean Squared Error (MSE) as the error measure, by fitting a Probability Density Function (PDF) to the transform coefficients and weighting the error for each range of coefficients by its respective DWT subband gain.A general scheme for Region Of Interest (ROI), including a non-linear scaling ROI, is presented in which the lower bitplanes of the foreground coefficients are delayed in exchange for better background reconstruction, achieving a more effective blending of foreground and background information.Finally, an implementation for both 32-bit and 64-bit ARM and x86 architectures was validated in an actual wireless underwater robotic teleoperation context.
Se presenta un nuevo algoritmo rápido y progresivo de compresión de imagen con Region De Interés (ROI) que emite un flujo optimizado de distorsión y trata una compresión de tasa de bits muy baja. Los tamaños de paquete variables definidos por el usuario lo hacen adecuado para el implementación de cualquier protocolo de comunicación, ya sea bajo el agua o en cualquier otro escenario, sin dejar de ser competitivo con los actuales compresores de última generación a mayores tasas de bits. Un algoritmo paralelo para la Transformada Wavelet Discreta (DWT) basado en el esquema de lifting es también presentado y se muestra como óptimo en el sentido de que ninguna otra implementación puede ser más rápida si se logra la saturación de la memoria. Se obtiene el mejor orden para los bits significativos y de refinamiento de los coeficientes de transformación, usando el Error Cuadrático Medio (MSE), al ajustar una función de densidad de probabilidad (PDF) a los coeficientes de transformación y ponderar el error para cada rango de coeficientes por su respectiva ganancia de subbanda DWT. Se presenta un esquema general para la Región de Interés (ROI), incluyendo un ROI de escalado no lineal, en el cual los planos de bit más bajos de los coeficientes de primer plano se retrasan a cambio de una mejor reconstrucción de fondo, logrando una efectiva combinación de información de fondo y de frente. Finalmente, se validó una implementación para las arquitecturas ARM y x86 de 32 bits y de 64 bits en un contexto de teleoperación robótica bajo el agua real.

Small animal positron emission tomography (PET) image analysis can be particularly challenging with heavily-lesioned animal disease models with limited tracer uptake such as the 6-hydroxydopamine (OHDA) lesioned rat model of Parkinson's disease. Methodology-related variations in measured values of 10% or 15% can obscure meaningful biological differences, so accurate analysis methods are essential. However, placing regions of interest (ROIs) on these images without additional guidance is unreliable, and can lead to significant errors in results. To address this problem, this work develops a partly atlas-guided method place ROIs on structures that lack specific binding with presynaptic dopaminergic tracers. The method is tested by correlation of PET binding potential (BP) with autoradiographic binding measurements, and with repeated PET scans of the same subjects, both with the presynaptic tracer ¹¹C-dihydrotetrabenazine (DTBZ). The method is found to produce reliable results. When directly comparing PET images of the same subject to detect changes, it is essential to minimize variations due to analysis method. To this end, a masking method for automated image registration (AIR) of PET images with dopaminergic tracer rat images is developed. Coregistration with AIR and separate ROI placement are compared and tested with repeated scans of the same rat with DTBZ, and are found to be equivalent. Kinetic modelling algorithms may also introduce bias or scatter to binding potentials (BP) calculated from TACs or in parametric images. To determine the optimal method for this step, algorithms for dopaminergic tracers are compared for small animal DTBZ, ¹¹C-methylphenidate (MP), and ¹¹C-raclopride (Rac) data. Among the tested methods is a new variant of the Logan graphical kinetic modelling method, developed in this work, that issignificantly less biased by target tissue TAC noise than the standard Logan approach. The modified graphical method is further compared with the Logan graphical algorithms with added-noise simulations. The simplified reference tissue model (SRTM) is found to have the best method for ROI TAC data, while the modified graphical algorithm may be preferred when generating parametric images.

Recent interest has emerged in microsensor platforms that are capable of supporting reconnaissance, surveillance and target acquisition operations. These devices typically consist of one or more sensors, signal conditioning and processing subsystems, a radio link and a power source. Sensors employed can range from acoustic, to seismic, to magnetic, to visible/infrared imagers.

A notable shortcoming of these systems is the fact that they are battery powered. The use of a finite power source places an upper limit on the lifespan of such a system. Thus, a major thrust in the development and usage of these microsensor platforms lies in the conservation of their limited energy resources. In attempt to reduce power consumption and hence extend the system's lifespan, communication bandwidths are often limited. In order to reduce the required bandwidth, much of the signal processing necessary to achieve a desired functionality must be performed within the microsensor platform itself.

This thesis effort provides this crucial bandwidth reduction by implementing in hardware an algorithm developed by the University of Maryland, which limits transmissions to the best view Regions-of-Interest (ROI) data, on the CAuS platform by BAE Systems. The hardware implementation was verified with a Matlab script that compared its results with those of the original algorithm. It was shown that these implementations were consistent for all of the data sets tested. Moreover, a subjective analysis, in which the detected ROIs were visually inspected, was performed to corroborate the former quantitative results.
Master of Science

El principal objetivo de esta tesis es analizar el proceso de Europeización de los grupos de interés regionales (GIRs), explorando de qué manera, en qué medida y debido a que razones los GIRs han transformado sus valores, su organización y sus estrategias, adaptándolas a la lógica y formas de la Unión Europea (UE). Un GIR europeizado tiene valores y objetivos que son promovidos por la UE y los comparte con organizaciones similares alrededor del continente. Tiene una organización que le da preeminencia a los asuntos relativos a la UE, y es capaz de buscar, recibir y administrar fondos de la UE con eficacia. Finalmente, posee estrategias que superan las fronteras nacionales y regionales, lo que no solo significa trabajar en organizaciones pan-Europeas sino también acercarse a instituciones y actores mas allá de las arenas regionales y nacionales para intentar influenciar el desarrollo de las políticas de la UE. El estudio de la Europeización de los GIRs presenta un interés teórico y empírico para la ciencia política, dado que se encuentra en la intersección entre los estudios sobre Europeización, grupos de interés y regiones, donde la investigación es aún incipiente (Roller & Sloat, 2002; Constantelos, 2004; McCauley, 2010). Al parecer la Europeización de los GIRs varía dependiendo de la región que se observe, lo que lleva a nuestro interés en explicar de qué manera ocurren estas variaciones, y cuál puede ser su motive. Con este objetivo, planeamos primero medir el grado de Europeización, de los GIRs, lo que nos permitirá comparar e identificar variaciones entre ellos. En segundo lugar intentaremos explicar esas variaciones, haciendo uso de la variable de autoridad regional creada por Marks et al (2008), y teniendo en cuenta los factores intervinientes (Risse et al, 2001; Borzel & Risse, 2003) que pudiesen mediar en esta Europeización. Para analizar la Europeización de los GIRs, esta tesis propone un estudio comparativo de los GIRs en tres regiones diferentes de Europa. Cataluña, Toscana y Gales fueron elegidas por sus similitudes (Keating, 2009; Keating & Wilson, 2009; 2010) y su diferencia en la variable independiente de la autoridad regional (Hooghe et al, 2008). Para evitar la interferencia de las características de la política analizada, esta investigación se enfoca solo en la política ambiental, en la cual la UE tiene una capacidad regulativa considerable, y que es implementada no solo a nivel nacional sino principalmente a nivel regional. España, Italia y el Reino Unido están involucrados en procesos de descentralización desde hace cuatro décadas, así como en recientes reformas estatutarias (Keating, 2009). Este estudio espera encontrar diferencias en la Europeización de los GIRs de estas tres regiones. En este sentido, Cataluña, Toscana y Gales presentan una oportunidad invaluable para la comparación.
The main objective of this thesis is to analyse the process of Europeanization of regional interest groups (RIGs), exploring in which way, to which measure and due to which reasons RIGs have transformed their values, organization and strategies, adapting them to the logic and ways of the European Union (EU). A europeanized RIG has values and objectives that are championed by the EU and shares them with similar organizations around the continent. It has an organization that gives EU issues a prominent position, and is capable of searching for, receiving and administering EU funds with efficiency. Finally, it has strategies broader than the regional and national frontiers, which not only means working on pan-European organization, but also approaching actors and institutions beyond the regional and national arenas to try and influence EU policy-making. The study of the Europeanization of RIGs presents an empirical and theoretical interest for political science, as it stands in the intersection of the studies of Europeanization, interest groups and regions, where research is still incipient (Roller & Sloat, 2002; Constantelos, 2004; McCauley, 2010). It would appear that the Europeanization of RIGs varies depending on the region we observe, which leads to our interest in explaining in which way these variations occur, and which could be its driving force. For this purpose, we first plan to measure the degree of Europeanization of RIGs, which will allow us to compare and identify variations amongst them. Secondly, we will try to explain those variations, making use of the variable of regional authority created by Marks et al (2008), and taking account of the mediating factors (Risse et al, 2001; Borzel & Risse, 2003) that could intervene in this Europeanization. To analyse the Europeanization of RIGs, this thesis proposes a comparative study of the RIGs in three different regions of Europe. Catalonia, Tuscany and Wales were chosen for their similarities in many of their characteristics (Keating, 2009; Keating & Wilson, 2009; 2010) but their difference in relation to the independent variable of regional authority (Hooghe et al, 2008). In order to avoid an interference of the features of the policy analysed, this research was designed to focus on only one policy. We have selected the environmental policy, in which the EU has a considerable regulative capacity, and which is implemented not only on the national level but mainly on the regional level. Spain, Italy and the United Kingdom have been involved for the last four decades in processes of devolution and decentralization, as well as recent statute reforms (Keating, 2009).The study expects to find differences in the Europeanization of RIGs from these three regions. The fact that they are similar in most other aspects helps minimize the possibility of other explanations. In this sense, Catalonia, Tuscany and Wales present an invaluable possibility for comparison.

This thesis examines factors that determine household reliance on interlinked informal credit contracts for fish in the Peruvian Amazon, and the degree to which implicit interest rates in these contracts are explained by transaction costs, administrative costs and lender risk.
A probit model was used to determine household likelihood to borrow, using survey data collected in the region. This likelihood is found to depend on access to alternative activities to generate income, household resilience to income volatility, and demographics: age, education and mobility.
High implicit interest rates (112%) are not explained by the average costs (67%) incurred by local lenders. Market access and household demand elasticity seem to be the main factors determining the degree to which forest peasants are exploited. Local lenders are found to receive credit at rates below the cost to non-resident lenders who use the credit relationship to secure a supply of fish.

 

Buying a house is for most people the biggest investment they will ever make. A lot of factors are taken in to consideration when looking for the perfect house; location, size, what state it is in and so forth. But since most people’s budgets are limited, the price is probably the most important aspect in the decision making process of buying a house. It is therefore highly interesting to note that since 1981, house prices in Sweden have increased with almost 400 percent.

This thesis examines the relationship between small house prices and macroeconomic factors in the Stockholm region during the period 1991 to 2007. By using macro economic theories complemented by data for all Stockholm’s municipalities in a OLS regression, the thesis will explain how the variables affects the small house prices in a boom, recession and over time.

The results and analysis reveals that as house prices rises, people tend to increase their spending on interest costs and vice versa if the prices falls. Furthermore, results show that in a boom, an existence of speculation is contributing to the rise while convergence is an important factor in a recession. The most important conclusion from this thesis is the fact that the influence of macroeconomic variables on house prices differs significantly, depending on if the economy is in a recession or a boom. Finally, the influence on the economy that the house- and real estate market possesses cannot be underestimated with its important effect on the credit market, inflation and asset market.

 

 

Husköp är för de flesta människor deras livs största investering och det är därför många faktorer som först måste vägas in varav den viktigaste förmodligen är priset. Huspriserna i Sverige har sedan 1981 nästan fyrdubblats, en utveckling som är mycket kraftigare än inflationen samma tid.

Den här kandidatuppsatsen avser att undersöka Stockholmregionens småhuspriser åren 1981-2007 och dess relation till makroekonomiska faktorer. Genom att använda en OLS regression med insamlad data för Stockholms alla kommuner och makroekonomiska teorier, visar vi hur utvalda makroekonomiska variabler påverkar småhuspriserna generellt, i hög- samt lågkonjunktur.

Resultat och analys visar att om småhuspriserna går upp är tenderar Stockholms befolkning att lägga en större del av deras inkomst på räntekostnader och tvärtom när priserna går ner. En psykologisk aspekt har en viktig del i dessa upp och nedgångar, i en uppgång startar en spekulationsperiod då människor vill vara en del ägandet i den uppåtgående husmarknad medans i en nergång skapas en sorts konvergens och en rad faktorer påverkar varandra i en spiralliknande nedåt trend. Denna trend kan förklaras i DiPasquales och Wheatons assets market model där det positiva förhållandet mellan marknader som hyresmarknaden, kreditmarknaden, byggmarknaden och tillgångsmarknaden står i fokus. Den viktigaste slutsatsen i uppsatsen är att makroekonomiska faktorer påverkar småhuspriserna helt olika beroende på om ekonomin är i en hög eller lågkonjunktur. Slutligen bör nämnas hur viktigt hus- och fastighetsmarknaden är för en ekonomi genom dess påverkan på kreditmarknaden och inflationen.

 

In this document is presented the work developed in the master thesis on "Region of Interest LiDAR". The goal is to develop a LiDAR capable of characterizing a region of interest with high precision. Taking into account the high error in a triangulation LiDAR for great distances, an ROI LiDAR could be able to complement a triangulation LiDAR, making it possible to distinguish different spots at great distances. This LiDAR is validated using a simulation tool developed in Matlab throughout the thesis, based on a system consisting of a mirror, a lens and a sensor, where all defined parameters, from lens diameter, the focal length of the lens, the distance between mirror and lens and sensor size influence the results. These values were defined through different tests so that, with the defined values, it was possible to achieve the objectives of this thesis. This work theoretically shows that a LiDAR ROI is doable and feasible, being an option to consider for the automotive industry, completing a triangular LiDAR.
Neste documento é apresentado o trabalho desenvolvido na tese de mestrado sobre "LIDAR para regiões de interesse". O objetivo é desenvolver um LiDAR capaz de caracterizar uma região de interesse com elevada precisão. Tendo em conta o erro elevado num LiDAR por triangulação, para grandes distâncias, um LiDAR para regiões de interesse conseguiria complementar um LiDAR por triangulação fazendo, com que seja possível distinguir diferentes pontos a grandes distâncias. Este LiDAR é validado usando uma ferramenta de simulação desenvolvida em Matlab ao longo da dissertação, baseada num sistema constituido por um espelho, uma lente e um sensor, onde todos os parâmetros definidos, desde o diametro da lente, a distância focal da lente, a distância entre espelho e lente e tamanho do sensor influenciam os resultados, estes valores foram definidos através de diferentes testes de modo a que com os valores definidos fosse possível atingir os objetivos desta tese. Este trabalho mostra, teoricamente, que um ROI LiDAR é fazível e viável, sendo uma opção a considerar para a indústria automóvel, completando assim um LiDAR por triangulação.
Mestrado em Engenharia Eletrónica e Telecomunicações

The advancement of medical imaging techniques such as fundus photography and breast magnetic resonance imaging (MRI) has shown tremendous improvement in the quality of multidimensional image produced. The image segmentation technology is used to partition the medical image into different regions for accurate identification and segregation of diseased area. Hence, the medical image is a vital entity to diagnose several pathological conditions. However, Multidimensional medical image analysis with automatic segmentation techniques these medical images have problems such as: 1. lack inherent spatial resolution; 2. contains different form of noise; 3. have boundary with the similar color intensity; and 4. populated with non-uniform illumination across the image and other imaging ambiguities. In many clinical studies, the segmentation process can be carried out either manually or automatically. Manual segmentation for the identification of several landmarks in medical images has been popularly considered, but is time consuming, tedious, error prone and observer-dependent. On the other hand, automatic segmentation technique are highly desirable because of its robustness, improved efficiency, reliability and faster computation. Therefore, the development of an automatic segmentation technique for the medical images has become an integral part of the medical diagnosis system that yields a practical insight. However, achieving a desirable result from automatic segmentation is still challenging. This is because; variation is seen in image features for different cases, even when produced with same imaging technique. The broad aim of this thesis is to identify the robust and automatic segmentation technique overcoming the issues seen in medical images and hence can assist doctors for the evaluation and detection of several pathologies. The objective is fulfilled by developing automatic segmentation algorithms and provide solutions to tackle challenges associated in two different imaging modalities: fundus photography (2D) and breast MRI (3D). The result is a series of work associated with the problem identification, analysis and a desirable solution with qualitative and quantitative validation. Specifically, we have strengthened the state-of-the-art by making the following novel contributions: 1. The analysis of retinal blood vessel is crucial for finding several pathological disorder that manifest through human eye. Therefore, blood vessel segmentation in fundus photography has great importance in medical image analysis. From the experiment, we observed that the retinal images with lesions, exudate’s, non-uniformed illuminations and pathological artefacts have intrinsic problems such as the absence of thin vessels and detection of false vessels. In our work, we developed an automatic blood vessel segmentation framework, which is effective in analysing retinal blood vessels on noisy, pathological and abnormal retinal images. Initially, the noise is minimized with image subtraction technique using morphological operation. Then, we investigated thin and thick blood vessels separately. Thin vessels are detected using local phase-preserving denoising, line detection, local normalization, and maximum entropy thresholding. Local phase-preservation denoising removes the additional noise while preserving phase information (detailed) of the image. Thick vessels are segmented using maximum entropy thresholding. The performance of the proposed methods is carried in four popular databases (DRIVE, STARE, CHASE DB1, HRF). The result shows that the proposed segmentation method is automatic, accurate and computationally efficient. Furthermore, the proposed methods is found to be superior when compared with the other methods in the state of art. 2. The automatic optic disc (OD) segmentation is a challenging task for the images, which are under the influence of noise, uneven illumination and pathologies. As per the state-of-art, development of OD segmentation is still a challenging task because of several reasons such as 1) Ophthalmic pathologies causes the change of color, shape or depth of OD 2) Retinal pathologies (exudate, lesion), sometimes possess similar properties causing a false identification of OD. 3) Different factors like illuminations and contrast irregularities, boundary artefacts and blurred image edges makes segmentation complicated and requires pixel to pixel analysis. 4) Also the texture feature of OD vary for different images, adding more challenges, thus requiring a pre-processing step prior to the segmentation. 5) If the vessels are dense and around OD, the identification the OD boundary becomes difficult. To solve the above-mentioned challenges, a new method for the accurate localization and detection of the optic disc is developed. The process utilizes kmeans clustering over foreground and background estimated images to obtain the brightest cluster. The obtained results are merged together to estimate the OD center. The OD boundary is then estimated using circular Hough transform (CHT) using the radius and center obtained in the initial step. The boundary estimation is also obtained from superpixels method. Finally, the OD boundary pixels are identified with the geometrical model over the edge information obtained from superpixels and CHT. The experiments carried out on seven publicly available database verify the efficiency of proposed methods. In addition, the outstanding results while compared with the other proposed methods in the current state of art proves the superiority of proposed methods. 3. A novel and accurate segmentation method of the breast region of interest (BROI) and breast density (BD) in breast MRI is proposed. The precise segmentation of BROI and BD is challenging, especially in noisy magnetic resonance images (MRI) due to similar intensity levels and the closely connected boundaries between BROI and other anatomical structure such as heart, lung and pectoral muscle. The segmentation of BROI is carried out in three major steps. Initially, we utilize adaptive wiener filtering and k-means clustering to denoised image by preserving edges and unwanted artefacts. Then, active contour based level sets is used to eliminate the heart area from the denoised image. Initial contour points for the active contour methods are determined by the maximum entropy thresholding and convolution method. Finally, a pectoral muscle is removed to obtain a BROI segmentation by using a morphological operations and local adaptive thresholding methods. The segmentation of BD is obtained with 4 level fuzzy c-means (FCM) thresholding methods on the result image obtained from BROI segmentation. The validation of proposed methods is performed using the 1350 breast images from 15 female subjects. The obtained result show that the proposed method is automatic, fast and efficient. 4. The segmentation of breast lesions in breast MRI is considered as a important and challenging task in medical image analysis. Noise, intensity similarity of lesions and other tissues, and variable shape and size of lesion are the primary challenges during the process of lesion segmentation. Hence, the framework for the accurate segmentation of breast lesion from the DCE MRI image is proposed. The framework is built using max flow and min cut problems in the continuous domain over the denoised image. The proposed method is achieved in three steps. Firstly, in the pre-processing step, the post contrast and pre-contrast image are subtracted. This is followed by image registration that benefits by enhancing the tumor area. Secondly, a phase preservation denoising and pixel-wise adaptive Wiener filtering technique are used which is followed by max flow and min cut problems in the continuous domain. A denoising mechanism clears the noise in the image by preserving the useful and detailed features such as edges. Then, a tumor detection is done using continuous max flow. Finally, morphological operation is used as a post-processing step to further delineate the obtained results. The efficiency of the proposed method is verified with the series of qualitative and quantitative experiments carried out on 21 cases with two different MR image resolution. The obtained results when compared with the manually segmented results demonstrates the quality of segmentation obtained from the proposed method. The segmentation experiments for all above-mentioned four proposed algorithms are performed on Matlab R2013b running under Intel(R) core(TM) i5-4570s CPU@ 2.90 Ghz with 8GB of RAM. In an effort to test the performance of the proposed algorithms, both the public and private datasets with the manually drawn ground truth image are used. Moreover, the qualitative and quantitative measurements were used as a way to verify the robustness of the proposed algorithms. Also, the result were compared with the recent state-of-art which demonstrate the enhanced performance and advancement of the proposed methods. Finally, our overall results on the proposed methods show that the proposed algorithms are automatic, accurate and computationally efficient.

碩士
國立成功大學
資訊工程學系
106
In these years, Location-Based Social Network, LBSN, becomes more and more popular. A platform for users to share their visits and experiences through check-ins records is provided and thereby many applications are being developed. Travel recommendation system is actually one of them. Users normally visit the spots in groups when they travel. They will only move to the next travel area after visited all their favorite spots and some nearby attractions in one area. We call this Region Of Interest (ROI). The recent travel recommendation systems (Point Of Interest, POI Recommendation) normal recommend the spots in amount of K to the users by the TOP-K calculation method. Users need to plan their trips from these results themselves. The POI Recommendation system does not help the users to plan a prefect visiting schedule entirely and thus cannot fulfill the purpose of personalized visiting schedule planning. Moreover, POIs recommended by the POI recommendation system are always too far away of each other or unsuitable for traveling. The planned schedules with these results are inaccurate. Therefore, we propose a scenic spot recommendation system which uses the LBSN's check-ins records to count every single-day schedule of the trips in different days in the offline section. Then divide the scenic spots in areas according to the days of trip by distance, probability and map. Finally recommend the suitable attraction areas to the users according to their preferences and the popularity of the attraction areas in the online section. So that such system is more in line with the two original intentions of the travel recommendation system: (1) in line with the users’ traveling behavior, (2) time-saving and personalized schedule planning.

碩士
國立東華大學
電機工程研究所
89
The ability to give higher priority to Region-of-Interest(ROI) is the emerging functionality for nowadays image/video coding. In this thesis, two different bit allocation strategies are proposed for Region-of-Interest(ROI) still image and video coding. Some improved issues are also proposed. For still image coding, we incorporate multiple ROI coding and data embedded functionalities into SPIHT codec with reversible Two-Ten integer wavelet transform, and propose two improvements of SPIHT algorithm and utilize context-based adaptive arithmetic coder to further enhance coding efficiency. Each ROI has individual ellipse or rectangle shape model and possesses own priority(reconstruction speed). The priority decides the order of processing for the coefficients at encoder and decoder. In addition, we propose a method called OENA to embed data. The data can be the meaningful image or the useful text for some special applications such as digital camera and digital library. We implement a remote monitor system to integrate all techniques of this portion. In this system, the luminance is compressed by an improved SPIHT codec, and the chrominance is embedded into the bitstream by OENA。The guarder can decide to use ROI or not, and the bit-rates to transmit to network. For video coding system, a region-based video codec based on the H.263+ video standard is set up. The associated rate control scheme is proposed for ROI coding through low bit-rate channels. The ROI can be defined statically or dynamically. A static ROI should be shaped to include the fixed space. The region of central rectangle is suitable for static ROI because the central region is usually more important than the surrounding region. The dynamic ROI is defined by a simple, fast, accurate face detection method that is used to locate the macroblocks that contain facial area in real time. We adjust the distortion weight parameter at macroblock layer by the rate control of TMN8 to ensure that the ROI gets better quality and more bits are allocated. From extensive experiment results, the proposed method can significantly improve subjective quality at facial region. It is very suitable for the applications of video conferencing and remote control.

碩士
國立臺北科技大學
電子電腦與通訊產業研發碩士專班
95
Image compression technique is categorized into two methods which are lossy and lossless. In general, the lossy compression method has higher compression ratio. The lossy compression method is used if the image coding does not require high quality. If the medical image loses precision, then maybe some errors will be generated. Therefore, the medical image needed to use lossless method for image compression. So, we use Region of Interest (ROI) technique to make the balance in image compression ratio and quality. Region of interest (ROI) is an image compression technology which is a new feature of JPEG2000 standard. The purpose of ROI is to transmit with better quality in needed image than other areas of the image. In this work, we propose a new flexible ROI image coding method, namely Two Steps Bitplanes Shifting (TSBS) algorithm, which can gain high image quality. The TSBS ROI method can adjust arbitrary the compression quality between ROI and background (BG) by setting scaling value. We compare Maxshift, BbBShift and TSBS methods with no ROI encoding under the bit rate used respectively. Compared with no ROI encoding, the bit rate increases average 4.5%, 2.37% and 0.36% by Maxshift, BbBShift and TSBS method, respectively. Therefore, the TSBS ROI coding method have lower bit rate than other methods.