La thérapie de resynchronisation cardiaque (CRT) est une thérapie électrique reconnue pour le traitement de l'insuffisance cardiaque liée à un asynchronisme cardiaque. Toutefois, environ un tiers des patients traités s'avèrent non-répondeurs à la CRT. Les travaux présentés dans cette thèse portent sur l'optimisation de la CRT par un meilleur positionnement de la sonde de stimulation du ventricule gauche (VG). L'approche proposée se décompose en deux temps. Une analyse pré-opératoire permet d'abord de définir les sites du VG optimaux et de caractériser leurs accès grâce à plusieurs étapes de recalage et fusion d'informations multimodales. Ensuite, un système d'assistance per-opératoire, basé sur la fusion des données pré- et per-opératoire, est proposé aux cliniciens afin de guider le geste vers les sites de stimulation pré-définis. L'analyse pré-opératoire utilisée pour la planification de la CRT s'inscrit dans la continuité des travaux menés au LTSI depuis plusieurs années. Dans ces travaux, de nouvelles méthodes pour la segmentation semi-interactive des veines coronaires en imagerie TDM ainsi que pour la caractérisation de la fibrose diffuse en IRM ont été proposées puis l'ensemble des méthodes développées au laboratoire ont été intégrés dans un même outil logiciel. Dans un second temps, une assistance per-opératoire est fourni à l'aide d'un recalage 3D/2D entre un modèle 3D de planification, issu de l'analyse pré-opératoire, et les images angiographiques 2D utilisées en routine clinique. Afin de permettre ce recalage, des méthodes d'extraction des images télé-systoliques et de segmentation automatique des veines coronaires dans ces dernières ont d'abord été définies. Ensuite, le recalage 3D/2D, effectué entre les veines coronaires 3D extraites en imagerie TDM et leur équivalent 2D dans les images angiographiques, permet la fusion des données pré- et per-opératoire. / Cardiac Resynchronization Therapy (CRT) is a recognized electrical therapy to correct cardiac asynchronism. However, about one third of implanted patients do not respond properly to the therapy. This thesis is focused on the improvement of the CRT through the optimization of the left ventricular lead placement. The proposed approach here is defined in two parts. Firstly, a pre-operative analysis defines the best left ventricle sites to stimulate thanks to several steps of registration and fusion of multimodales informations. Secondly, a per-operative assistance system is proposed in order to guide clinicians to use these pre-defined implantation sites. The CRT planification is a research theme in the LTSI for many years. In this thesis, novel semi-automatic segmentation methods have been developed for both the coronary veins in CT and diffuse fibrosis characterization in MRI. The previous developments and these novel methods have been gathered and integrated in one software. Then, a 2D/3D registration between angiographic frames, used in clinical routine, and a 3D model produced by the pre-operative analysis is used to assist the implantation. To perform the registration, dedicated methods to extract end-systolic images and segment coronary veins in these images have been developed. Next, the registration is performed between the 3D coronary veins (extracted from the CT volumes) and their 2D equivalent which allows the pre- and per-operative data to be fused.

Thesis advisor: Ana M. Martinez-Aleman / This qualitative study employed a Critical Race Theory (CRT) lens to gather a deeper understanding the racialized experiences of students of color (SOC) at a PWI, and how these experiences impact the way in which they understand, conceptualize, and/or actualize student leadership on campus. This study presents the lived experiences of twenty-five SOC. Participants shared their experiences and perceptions through individual semi-structured interviews, with an opportunity to also participate in a focus group. Findings revealed that the ways in which participants view how race is socially constructed on campus and their encounters with normalized racism (such as their experiences with microaggressions, the lack of diversity, the negative racial climate, and the racial segregation on campus) seemed to profoundly impact participants lived experiences and perceptions. Participants in this study exhibited a strong pull towards SOC groups (both for participation and leadership expression), citing a desire to seek involvement with individuals of similar/racial and ethnic background, a responsibility to give back to their racial/ethnic group, and seeking a group that affirmed their sense of identity as some of the top reasons they joined SOC groups. However, participants’ perceptions of predominately White groups on campus, encounters with normalized racism, and the way they view student groups are valued (or undervalued) on campus seems to suggest that the campus racial climate may play a powerful role in students’ decision making around co-curricular involvement and leadership expression. The findings strongly intimate that the college campus remains a microcosm of larger society in that it continues to perpetuate normalized racism as a product of inherent (and biased structures), influencing students’ leadership perceptions and expression. This study recommends that institutions assess the racial landscape on campus in terms of perceived and actualized student leadership, be willing to engage in experimentation on different practices that will foster a greater sense of inclusivity within student leadership, and take active steps towards creating permanent inclusive change. / Thesis (PhD) — Boston College, 2016. / Submitted to: Boston College. Lynch School of Education. / Discipline: Educational Leadership and Higher Education.

This thesis is based on three different focus groups held in the summer of 2018 with a total of twelve Black students. It examines a group of Black students’ experiences of racist microaggressions on the campus of a large comprehensive Canadian university situated in an urban setting. Using Critical Race Theory it analyzes how seemingly neutral comments, slights, snubs or representations by white students and professors contributes to a culture of anti-Black racism on this campus. Key to this analysis is the shift from traditional forms of racism to more subtle forms of racism in contemporary society, and the role that institutions play in reproducing racism. Microaggressions thus characterise the subtle way in which racism is perpetuated in contemporary society. The experiences described by the twelve students in this research study demonstrate the prevalence of microaggressions in the lives of Black students in this Canadian university. Furthermore, the four broad themes emerge from the focus group discussions: the lack of diversity in the student population and faculty, the invalidation of Black experiences, stereotypical representations of Black people and cultures, and gendered racism, give further nuance to the types of messages that Black students are exposed to at this university. This analysis produces a deeper understanding of how these micro-level interactions contribute to the broader culture of racism on campuses.

Introduction Nearly all flat panel video display monitors have luminance and colour variations as the angle of view varies from the monitor’s perpendicular. The new MicrotileTM displays developed by Christie Digital are no exception to this general finding. A review of any book on colour science will show that there is substantial amount of literature on just noticeable colour differences within various colour spaces. Despite the wealth of data on the topic, there is no general consensus across different industries as to which colour space and colour difference equations are appropriate. Several factors like the background colour, object size, texture of the stimulus are different for different studies; these factors make it very difficult to determine precisely the effect of viewing angle on the perception of coloured images on the Microtiles display based on previous research. Hence, the objective of this thesis was to quantify the measured colour shifts of a Microtile display at different viewing angles, in steps of perceptible thresholds and to evaluate the acceptability of distortions at different viewing angles for complex scenes. Methods A preliminary experiment was setup to study the behaviour of Microtile display primaries as a function of viewing angle. The aim was to measure the shift in hue and luminance of the three primaries at different eccentricities (from 0o to 40o). The measured trend was used to simulate Microtile shifts on complex images for the rating task. In the first part of the perceptibility experiment, three reference colours were picked and 12 vectors heading towards the blue-yellow region of the L*a*b* colour space (pertaining to the colour shifts noticed with the Microtile displays). A uniform reference colour was presented in three of the four quadrants on the CRT monitor and one quadrant changed colour in the direction of the sampled vector. An adaptive, four alternate forced choice procedure was employed to determine thresholds for each of the 3 reference colours. The adaptive technique used was a ZEST paradigm. In the second part of the perceptibility experiment, eighteen directions were sampled around each reference colour. The rating task was based on simulating the measured attenuations of the Microtile primaries on complex scenes. Subjects rated the images both in terms of acceptability/unacceptability and as percentage image degradation. The simulation was presented on three static complex images, car, landscape and portrait. A total of 60 subjects participated in the study, 20 subjects for each experiment. All subjects were between the age group of 15 to 35 years of age and underwent battery of colour vision tests before being included in the study. All subjects included had average to superior colour discrimination as categorized using the FM-100 Hue discrimination test. Results Study1: The preliminary study on Microtile display characteristics as a function of viewing angle showed that all the three primaries decreased in luminance with change in viewing angle. The red primary decreased at a faster rate compared to the other two primaries. The trend presents as a decrease in luminance with the hue shifting towards the blue-green region of the CIE1974 L*a*b* space. Study 2: Results from both the first and second parts of the perceptibility experiment showed that the vectors sampled in different directions approximated to ellipsoids in the L*a*b* colour space. This finding was consistent with the colour discrimination literature. Vectors on the equi-luminance plane were significantly longer than the vectors on the non equi-Luminance plane. Results showed that the average perceptibility thresholds in the non equi-luminance direction were lower than 1∆ELab¬¬¬¬. Study 3: Results from the rating experiments showed that irrespective of the complexities in the images, distortions greater than five times thresholds were less than 50% acceptable and were rated to be at least 30% degraded. This corresponds to a viewing angle greater than 10o for a Microtile display. The relationship between the stimulus (ΔE) and subjective Image degradation judgements followed a linear relationship, with the portrait and landscape having similar functions, whereas the car was rated more degraded at lower ΔEs and less degraded at higher ΔEs compared with the other two scenes. Conclusion Perceptibility thresholds for different reference colours showed that the conventionally used calibration precision of 1 ΔELab is a lenient criterion. Perceptibility thresholds are at least 25% less for the Microtile display reference condition. From the results of the rating data a distortion greater than five times thresholds is less than 50% acceptable and appears to be at least 30% degraded for static complex images. However, the image quality judgments appear to be related to scene context, which requires further study.

Much research suggests that there exist universal colour names. Investigations involving paint and paper media have revealed co-incidence of especially salient names and their concomitant sensations, within and between cultures. These names have been called Basic Colour Terms (BCfs), and their prototypical sensations focal colours (or foci). The highest levelof colour name development within cultures includes eleven BCfs. A literature review revealed certain omissions in the colour naming work. Firstly was a lack of usage of CRT-baseddisplay of colours. This was considered an important omission given the implicit, but largely untested assumption that CRT and surface media may be equivalent. A second omission identified was a lack of detailed quantification of realistic naming behaviour. Two CRT-based experiments were then devised to quantify colour naming, one involving unconstrained naming of colours, one involving selection of which colours were exemplars of (thirteen) pre-generated colour names. These experiments revealed certain regularities in naming within a (perceptually uniform) colour space. Thus a naming space and its underlying structure was obtained. Naming space was found to be a composite of they way membership of (BCf) categories was expressed, and an underlying set of five fundamental colour sensations. Evidencewas then forthcoming that this structure might be modelable. The quantified data obtained was then used to investigate the search-efficacy of easy to name colours. Such easy to name palettes were generated, based on the data obtained, and compared with colorimetrically matched, and highly discriminable palettes. It was found that easy to name as a colour palette variable was meaningful, and capable of adjusting user performance, despite evidence that individuals may possess relatively stable, idiosyncratic colour vocabularies. That CRT work has generality was verified by comparison of foci obtained from a series of studies involving different media. Although some differences were evident, these followed clear patterns which were not inconsistent with universal colour naming. This thesis suggests that there exist complex aspects of colour naming behaviour which are nevertheless understandable, and largely predictable. Such theoretical data should allow for improvements in certain human-interactions, where tasks involve naming colours.

Despite the lack of clarity on how sport delivers the benefits intended, sport continues to be positioned as a panacea for social disparities (Coalter, 2010). The inconsistent and sometimes nonexistent evaluation of sport has raised doubt about sport’s capacity to deliver the benefits desired (Broh, 2002; Chalip, 2006; Coakley, 1979; Coakley, 1993). In worse cases, sport has been considered complicit in reinforcing the same oppressive social structures that created the initial need for its intervention (Hartmann & Depro, 2006; Hartmann, 2003; Shaw, Frisby, Cunningham, & Fink, 2006; Spaaij, 2009). The belief that sport can provide benefits stems from the recognition that there are two groups of people: the empowered (i.e., those who employ sport for development), and the disempowered (i.e., those who are targeted to participate in these programs). Darnell (2007) asserts that “within the development through sport movement, a well-intentioned and benevolent ‘mission’ of training, empowering, and assisting is not only based upon, but to an extent requires, the establishment of a dichotomy between the empowered and the disempowered, the vocal and the silent, the ‘knowers’ and the known” (561). The crux of this assertion lies in the notion that the benefits provided through sport serve as social control mechanisms by reifying the values of the empowered as those that should be desired and reinforcing the social hierarchies that oppress the disempowered through the controlled (unequal) allocation of resources. Latent in the intent of these sport-for-development programs is the need to continually identify and socially anchor the historically disempowered. Social myths about their inferiority overshadow how social class, further distinguished by race and gender, was historically fashioned by the unequal distribution of resources and overpower the voices of those who are marginalized through this process. Therefore, what is considered “beneficial” becomes a contest between which group can put the most resources behind their ideals as opposed to the expressed needs of the participants (Coalter, 2007; Darnell, 2007; Spaaij, 2009). To better understand what shapes perceptions about the benefits obtained from sport participation, the purpose of this study was threefold: (1) to determine what players and coaches perceive as the benefits obtained by players through basketball and what benefits they perceive to be important; (2) to determine whether players and coaches perceive that players obtain benefits to the same degree that they feel they are important; and (3) to understand the differences in these perceptions based on gender, race, SES, and role (i.e., player or coach). Upon receiving IRB approval, a pilot study was conducted on high school athletes (N= 450) to ascertain the benefits they obtained from high school basketball. In SPSS, exploratory factor analyses with varimax rotation were conducted on 109 benefits identified in the literature to determine which groups of benefits were salient to high school basketball players. From the initial factor analysis, 23 factors emerged. In addition to feedback from sport-for-development researchers, coaches, and players, a second pilot study (N= 69) was conducted to refine the categories of benefits players obtained. The final instrument contained 41 items in ten categories of benefits: Academic Resiliency, Self-Expansion, Self-Discipline, Analytical Thinking Skills, Moral Value Development, College Preparation, Leadership Training, and Relationships with Others, Sense of Community, and Career Development. Cronbach’s alpha was used to test reliability of each category and all were found to be acceptable for this study Nunnally (1978). The instrument was available in paper form and electronic form for players and coaches to complete in a four-week period. The final sample included 237 high school basketball players and 164 high school basketball coaches from Texas. First, two MANOVAs (one for benefits obtained and one for importance) were conducted to examine the potential interactions among gender, race, SES, and role in perceptions of benefits obtained and the importance of those benefits. Results of the MANOVAs were considered significant at α = .10. Next, paired-sample t-tests were conducted to determine whether players and coaches perceived that players received the same benefits that were deemed important. Finally, one sample t-tests (against the neutral point of the scale, 4) were used to determine which benefits were perceived to be obtained and which were considered important by players and coaches. T-tests were considered significant using Bonferroni criteria. The results of the MANOVAs included a three-way interaction between race, gender, and role that was significant in determining the perceived benefits obtained through sport. These results reinforce the need to analyze sport from a transdisciplinary lens to understanding the personal and structural factors shaping the needs of sport participants and subsequently creating culturally responsive sport component to provide the desired benefits. SES was used as a proxy for social class, more specifically, for one's access to resources, and was not found to be significant in determining the perception of benefits obtained from sport. This finding suggests that people marginalized by class differences may have a false consciousness about the benefits sport can provide despite the evidence that these individuals are not receiving benefits at levels comparable to more privileged groups and even worse, that sport participation can be detrimental to their development. In light of the findings that African-American women perceive more strongly that they obtain benefits from sports than do their male counterparts, further exploration is needed on how the experience of sport is influenced by hegemonic structures based on race and gender. To this end, practical implications for implementing sport-for-development programs including promoting culturally responsive training and implementation of programs (Ladson-Billings, 1990) that employ the resources available to foster the intended benefits and more importantly, to create more sustainable programs. Another key finding was that race, gender, role, and SES were significant in influencing the benefits perceived to be important. While the results showed that "sport is good" for providing the benefits observed, the differences in how well these benefits are obtained by race and gender suggest that further investigation is needed in understanding what are the mechanisms that allow sport to be "good" in providing these groups with benefits and in determining how athletes perceive sport as the channel for receiving benefits. Both findings push for more organic and long-term studies in the benefits of sport participation. Using the tenets of Critical Race Theory, theoretical implications include employing a socioecological approach to understanding how needs and benefits are conceptualized, the use of more emic approaches to studying these concepts, and providing more agency to the individuals in researching and understanding their needs and the benefits they desire from sport (along with the potentially negative implications of sport participation). The results promote the need to look specifically at one's access to resources, race, and gender in determining the components necessary and sufficient to providing benefits through sport. The concept of hegemony posits that these factors are not conditions inherent to an individual but identities and social positions constructed by the larger society. Therefore, sport researchers must create concepts of researching "needs" and "benefits" that are reflective of the individual as well as cultural and environmental factors that shape sport participation. These concepts must also be organic, taking into consideration that factors influencing the needs of participants are changing in concert with social norms and their effects on one's identity and access to resources. The results of this study also provide practical implications for recognizing that sport does not exist in vacuum and to be effective in providing participants with the intended benefits, sport must be culturally responsive (Gay, 2000; Ladson-Billings, 1992). To this end, sport administrators should be mindful of the cultural and structural factors that shape the students’ environment and consequently their identities and needs, by implementing sport components that work on multiple levels. Administrators and participants should also examine the ways that sport may impact them in negative ways, particularly if those negative impacts are masked by potential benefits (Bruening, 2005; Glover, 2007; Harrison, Sailes, Rotich, & Bimper, 2011). Giving voice to the participants, engaging school and community officials in providing access to resources, and using goal-setting to help students exercise more agency in shaping their sport experience were also practical implications from this study. / text

Over the last decade, the demand for privacy and data confidentiality in communication and storage processes have increased exponentially. Cryptography can be the solution for this demand. However, the critical issue occurs when there is a need for computing publicly on sensitive information or delegating computation to untrusted machines. This must be done in such a way that preserves the information privacy and accessibility. For this reason, we need an encryption algorithm that allows computation on information without revealing details about them. In 1978 Rivest, Adleman and Dertouzos raised a crucial question: can we use a special privacy homomorphism to encrypt the data and do an unlimited computations on it while it remains encrypted without the necessity of decrypting it? Researchers made extensive efforts to achieve such encryption algorithm. In this paper, we introduce the implementation of the CRT-based somewhat homomorphic encryption over the integers scheme. The main goal is to provide a proof of concept of this new and promising encryption algorithm. / Graduate

The purpose of this study is to re-analyze existing findings in order to demonstrate and summarize relationships between criteria and the sub-scales/dimensions of the Conditional Reasoning Test for Aggression (CRT-A): Externalizing, Internalizing, and Powerlessness. A CRT-A sub-scale was expected to relate more strongly with criteria categorized as being more relevant to the dimension that is represented by that sub-scale. For criteria that were categorized as relevant to only a subset of the dimensions represented by CRT-A sub-scales, the regression of a criterion on all three sub-scales was expected to create a better fitting model than the regression of a criterion on the CRT-A total score alone. Scales were also expected to interact to predict criteria. This was expected to be most likely when multiple dimensions of implicit aggression were activated by environmental factors to influence specific behaviors. Support was found for all expectations

Introduction Nearly all flat panel video display monitors have luminance and colour variations as the angle of view varies from the monitor’s perpendicular. The new MicrotileTM displays developed by Christie Digital are no exception to this general finding. A review of any book on colour science will show that there is substantial amount of literature on just noticeable colour differences within various colour spaces. Despite the wealth of data on the topic, there is no general consensus across different industries as to which colour space and colour difference equations are appropriate. Several factors like the background colour, object size, texture of the stimulus are different for different studies; these factors make it very difficult to determine precisely the effect of viewing angle on the perception of coloured images on the Microtiles display based on previous research. Hence, the objective of this thesis was to quantify the measured colour shifts of a Microtile display at different viewing angles, in steps of perceptible thresholds and to evaluate the acceptability of distortions at different viewing angles for complex scenes. Methods A preliminary experiment was setup to study the behaviour of Microtile display primaries as a function of viewing angle. The aim was to measure the shift in hue and luminance of the three primaries at different eccentricities (from 0o to 40o). The measured trend was used to simulate Microtile shifts on complex images for the rating task. In the first part of the perceptibility experiment, three reference colours were picked and 12 vectors heading towards the blue-yellow region of the L*a*b* colour space (pertaining to the colour shifts noticed with the Microtile displays). A uniform reference colour was presented in three of the four quadrants on the CRT monitor and one quadrant changed colour in the direction of the sampled vector. An adaptive, four alternate forced choice procedure was employed to determine thresholds for each of the 3 reference colours. The adaptive technique used was a ZEST paradigm. In the second part of the perceptibility experiment, eighteen directions were sampled around each reference colour. The rating task was based on simulating the measured attenuations of the Microtile primaries on complex scenes. Subjects rated the images both in terms of acceptability/unacceptability and as percentage image degradation. The simulation was presented on three static complex images, car, landscape and portrait. A total of 60 subjects participated in the study, 20 subjects for each experiment. All subjects were between the age group of 15 to 35 years of age and underwent battery of colour vision tests before being included in the study. All subjects included had average to superior colour discrimination as categorized using the FM-100 Hue discrimination test. Results Study1: The preliminary study on Microtile display characteristics as a function of viewing angle showed that all the three primaries decreased in luminance with change in viewing angle. The red primary decreased at a faster rate compared to the other two primaries. The trend presents as a decrease in luminance with the hue shifting towards the blue-green region of the CIE1974 L*a*b* space. Study 2: Results from both the first and second parts of the perceptibility experiment showed that the vectors sampled in different directions approximated to ellipsoids in the L*a*b* colour space. This finding was consistent with the colour discrimination literature. Vectors on the equi-luminance plane were significantly longer than the vectors on the non equi-Luminance plane. Results showed that the average perceptibility thresholds in the non equi-luminance direction were lower than 1∆ELab¬¬¬¬. Study 3: Results from the rating experiments showed that irrespective of the complexities in the images, distortions greater than five times thresholds were less than 50% acceptable and were rated to be at least 30% degraded. This corresponds to a viewing angle greater than 10o for a Microtile display. The relationship between the stimulus (ΔE) and subjective Image degradation judgements followed a linear relationship, with the portrait and landscape having similar functions, whereas the car was rated more degraded at lower ΔEs and less degraded at higher ΔEs compared with the other two scenes. Conclusion Perceptibility thresholds for different reference colours showed that the conventionally used calibration precision of 1 ΔELab is a lenient criterion. Perceptibility thresholds are at least 25% less for the Microtile display reference condition. From the results of the rating data a distortion greater than five times thresholds is less than 50% acceptable and appears to be at least 30% degraded for static complex images. However, the image quality judgments appear to be related to scene context, which requires further study.

Many philosophers have worried about what philosophy is. Often they have looked for answers by considering what it is that philosophers do. Given the diversity of topics and methods found in philosophy, however, we propose a different approach. In this article we consider the philosophical temperament, asking an alternative question: what are philosophers like? Our answer is that one important aspect of the philosophical temperament is that philosophers are especially reflective: they are less likely than their peers to embrace what seems obvious without questioning it. This claim is supported by a study of more than 4,000 philosophers and non-philosophers, the results of which indicate that even when we control for overall education level, philosophers tend to be significantly more reflective than their peers. We then illustrate this tendency by considering what we know about the philosophizing of a few prominent philosophers. Recognizing this aspect of the philosophical temperament, it is natural to wonder how philosophers came to be this way: does philosophical training teach reflectivity or do more reflective people tend to gravitate to philosophy? We consider the limitations of our data with respect to this question and suggest that a longitudinal study be conducted.