Multi-modality imaging is a possible solution for overcoming individual modality limitations. With the use of modality specific contrast agents, contrast-enhanced multi-modality imaging may provide a more comprehensive evaluation of tumour characteristics. This may be possible by combining ultrasound and magnetic resonance imaging, whose contrast agents behave differently within the microvasculature. A novel, microvascular, and leaky phantom is presented that permits ultrasound contrast agents to remain entirely within the mimicking vascular compartment while the magnetic resonance contrast agents may freely diffuse between the mimicking vasculature and tissue compartments. The results show that the phantom is a useful tool for investigating the combination of contrast-enhanced ultrasound and magnetic resonance imaging. This work motivates further combined contrast-enhanced imaging studies, with future work to incorporate additional modalities.

Interferometry and holography are two well-known methods for measuring distances, positions, vibrations, index of refraction etc. In these methods a coherent light source is used to create interference between different parts of the light. Since the wavelength of the light is used as reference it is possible to achieve very good accuracy in the measurements. The need of small and cheap light sources for these applications is large and an interesting alternative would be to use ordinary semiconductor diode lasers. These are unfortunately not designed to give sufficiently good coherence. In this Master Thesis work investigations of how the coherence of semiconductor diode lasers is affected by changes in temperature, injection current and between different individuals are performed. A Michelson interferometer is used to create an interference pattern where the contrast then can be analyzed. The contrast is related to the coherence of the laser, i.e., good coherence will give high contrast. The results show that in order to drive the laser in a stable way it is better to hold the temperature constant and varying the injection current until the wanted output power is achieved instead of doing the opposite. The results also indicate that the best coherence is achieved for low temperatures (around 10 OC) and high injection currents (around 80 mA). During these conditions a contrast of 70 % -80 % is achieved. The result of this Master Thesis work gives a hint on how to run a semiconductor diode laser in a stable way.

Frederic Francois Chopin was the first composer to write a Ballade as an instrumental musical work. From 1831 to 1843 he wrote a total of four Ballades. This study primarily discusses Chopin's use of contrast in the Ballade in G minor, opus 23 and in the Ballade in F minor, opus 52. First, it discusses the background of Chopin's life and his composition of the Ballades. Second, it reviews the origin and development of those genres of poetry and music called "ballad" or "ballade" that relate to Chopin's Ballades. Finally, it focuses on the ways that Chopin utilizes contrast in the G minor Ballade and the F minor Ballade, on whether or not the contrasts appear differently in different musical forms, and on allowing the performer to understand the unique kinds of writing in the Ballades. It is hoped that the performer who plays the Ballades, in addition to having the required technical ability, is also able to understand in more depth the content of these Ballades and the ideas they are meant to express.

Diss. (sammanfattning) Uppsala : Univ., 2001. / Härtill 4 uppsatser.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 39-45). Also available via the Internet.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 43-46). Also available via the Internet.

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 176-185).

Dans le cadre de cette thèse nous nous sommes intéressés à l’amélioration de la qualité visuelle des images, en rehaussant le contraste des images. Nous avons proposé, tout d’abord, une méthode de rehaussement simple et efficace s’inspirant du système visuel humain. Cette méthode est efficace,quand elle est appliquée aux images naturelles en couleur, ou monochromes. La méthode proposée est ensuite améliorée pour pouvoir rehausser d’autre type d’image comme les images médicale, telles que les images de rétine et l’endoscopie. Par la suite, nous nous sommes aussi intéressés aux rehaussements des images médicales et en particulier aux images de mammographie et nous avons donc proposé une méthode de rehaussement de contraste qui leur est spécifiquement dédiée. Au final,nous nous sommes intéressés à l’évaluation des méthodes de rehaussement proposées et aux différentes approches existantes dans la littérature. La méthode d’évaluation proposée s’appuie sur l’analyse radiale et angulaire du spectre d’énergie de Fourier. La validation de notre méthode de rehaussement de contraste a été faite en utilisant des échantillons d’images de 2 bases et en utilisant un test subjectif pour la comparer à d’autres méthodes de rehaussement. La note subjective finale de MOS, obtenue par la moyenne des notes des observateurs, montre la fiabilité de notre méthode de rehaussement de contraste et son intérêt par comparaison aux autres méthodes classiques. / The aim of this thesis is to propose new methods for image enhancement based on oriented and multi-scale transforms using some perceptual criteria. The first part of the thesis is devoted to the development of a simple and efficient contrast enhancement method inspired from the human visual system. This method is evaluated on a set of natural color and monochrome images. The obtained results are evaluated subjectively and by using objective measures based on energy spectrum analysis and perceptual criteria. The enhancement technique is also extended to some medical images, such as mammography and endoscopy images. A special contrast enhancement method adapted to mammography is then proposed. It is based on a segmentation process using a priori information on the mammography images. The last part of the thesis is devoted to image enhancement evaluation. A critical literature survey of image enhancement evaluation methods is provided. The evaluation method proposed in this thesis is based on the radial and angular analysis of the Fourier powerspectrum. Another perceptual approach is proposed to evaluate the output. This method is based on the analysis of the visibility map computed by using a pyramidal contrast. The evaluation is performed on some samples taken from two databases. Both subjective and objective evaluations demonstrate the efficiency of the proposed image enhancement methods.

archives@tulane.edu / 1 / Genevieve Mattei

In today's rapidly urbanized world, this paper expores the urgent need to reclaim tranquility and practice wellness through Architecture. Emphasizing the significance of reimagining communal spa experiences as sanctuaries for nurturing well-being and fostering genuine connections, it focuses on the symbiotic relationship between light and architecture. The thesis focuses on the therapeutic characteristics of light and space as it takes inspiration fromthe ancient Roman Bath, highlighting the calming effects of water features and mood-altering properties of light. Recognizing light as essential for survival and integral to our daily lives, the project seeks to harness its potential alongside water to create harmonious sensory experiences. In an endeavor to revive communal bonds and elevate collective wellness, this project embarks on a journey of contrast, juxtaposing light and water within spa design. Acknowledging the properties of light that play an indispensable role in human survival and its profound influence on our circadian rhythm, the project strategically integrates diverse lighting techniques. From natural daylight streaming through strategically positioned apertures to carefully curated artificial illumination, every aspect is orchestrated to evoke specific moods and enhance the sensory journey. Complementing this interplay of light, water features are strategically incorporated within the project. These elements are not merely aesthetic additions but are imbued with therapeutic properties, providing avenues for relaxation and rejuvenation. Through this integration of light and water, the spa becomes a canvas where contrasts converge, offering visitors a multifaceted experience that stimulates the senses and nurtures well-being. The juxtaposition of light and shadow, stillness and movement, creates dynamic spaces that encourage contemplation and connection. As individuals immerse themselves in this harmonious environment, they are invited to rediscover a sense of unity with their surroundings and with each other. Thus, the restoration of communal bonds and the enhancement of collective wellness emerge as inherent outcomes of this deliberate synthesis of contrasts within spa design. / Master of Architecture / In an era where the rush of modern life overwhelms our senses, designing a spa isn't merely an architectural endeavor; it's an act of reclaiming tranquility. The disappearance of communal spa experiences mirrors our detachment from shared spaces and genuine connections. In order to address the recurring issues, this thesis explores how we can resurrect the spa, we rekindle a sanctuary where people converge to nurture their well-being, fostering a sense of unity and rejuvenation. Beyond luxurious amenities, it's a symbol of restoring communal bonds and prioritizing collective wellness. As this thesis aims to tackle the connection between Light and Architecture, the core ideology is to find therapeutic spaces that are driven by light. Our sense of sight and touch has always been an intergral part of experiencing a space. Light can affect our mood, both its presence and absence has remarkable effects on our mind. As the primary source for photosynthesis, light is crucial to our food cycle, therefore is the major deciding factor for our survival. Our circadian rhythm is attuned to daylight and contributes to our biological clock. Understanding the importance of light and water in our everyday lives, as well as the importance of contrast to our sense of perception, this project aims to maximize their concerted effort to create a harmonious journey orchestrated to explore the full potential of the sensory experience.