<p>Nowadays biometric identification is used in a variety of applications-administration, business and even home. Although there are a lot of biometric identifiers, fingerprints are the most widely spread due to their acceptance from the people and the cheap price of the hardware equipment. Fingerprint recognition is a complex image recognition problem and includes algorithms and procedures for image enhancement and binarization, extracting and matching features and sometimes classification. In this work the main approaches in the research area are discussed, demonstrated and tested in a sample application. The demonstration software application is developed by using Verifinger SDK and Microsoft Visual Studio platform. The fingerprint sensor for testing the application is AuthenTec AES2501.</p>

The number of newly developed chemical entities exhibiting poor water solubility has increased dramatically in recent years. In many cases this intrinsic property results in poor or erratic dissolution in biological fluids. Improving aqueous solubility of these compounds, even temporarily, can have a significant impact on in vivo performance. Single phase amorphous solid dispersions of a drug and polymer have emerged as a technique to not only increase the level of drug supersaturation but also maintain these levels for extended periods of time. Hot-melt extrusion (HME) has become the preferred processing technique to prepare systems such as these but has a number of limitations that prevent the successful formulation of many drug substances. Within this dissertation, the use of concentration enhancing polymers was investigated in parallel with a thorough evaluation of a novel fusion-based processing technique, KinetiSol® Dispersing (KSD), to prepare single phase amorphous solid dispersions that could not be successfully prepared by HME. Studies showed that the KSD technique is suitable for rendering thermally labile and high melting point drug substances amorphous through a combination of frictional and shearing energy. Compounds such as these were shown to degrade during HME processing due to relatively long residence times and low shear forces. Similarly, the KSD process was shown to successfully process solid dispersion compositions containing a high viscosity polymer with significantly lower levels of polymer degradation than obtained by HME processing. In the final study, KSD processing was used to prepare solid dispersions containing the hydrophilic polymer Soluplus[superscript TM] and methods were evaluated to formulate a tablet with rapid tablet disintegration characteristics, a requirement for sufficient dissolution enhancement. Combined, the studies demonstrated the effectiveness of combining proper polymer selection and formulation approaches with a suitable processing technique to form solid dispersion systems that provide rapid and extended durations of supersaturation. / text

This PhD work was partially supported by the European LIREC project (Living with robots and interactive companions) a collaboration of 10 EU partners that aims to develop a new generation of interactive and emotionally intelligent companions able of establishing and maintaining long-term relationships with humans. The project takes a multi-disciplinary approach towards investigating methods to allow robotic companions to perceive, remember and react to people in order to enhance the companion’s awareness of sociability in domestic environments. (e.g. remind a user and provide useful information, carry heavy objects etc.). One of the project's scenarios concerns remote human-human communication enhancement utilising autonomous robots as social mediators which is the focus of this PhD thesis. This scenario involves a remote communication situation between two distant users who wish to utilise their robot companions in order to enhance their communication and interaction experience with each other over the internet. The scenario derived from the need of communication between people who are separated from their relatives and friends due to work commitments or other personal obligations. Even for people that live close by, communication mediated by modern technologies has become widespread. However, even with the use of video communication, they are still missing an important medium of interaction that has received much less attention over the past years, which is touch. The purpose of this thesis was to develop autonomous robots as social mediators in a remote human-human communication scenario in order to allow the users to use touch and other modalities on the robots. This thesis addressed the following research questions: Can an autonomous robot be a social mediator in human-human remote communication? How does an autonomous robotic mediator compare to a conventional computer interface in facilitating users’ remote communication? Which methodology should be used for qualitative and quantitative measurements for local user-robot and user-user social remote interactions? In order to answer these questions, three different communications platforms were developed during this research and each one addressed a number of research questions. The first platform (AIBOcom) allowed two distant users to collaborate in a virtual environment by utilising their autonomous robotic companions during their communication. Two pet-like robots, which interact individually with two remotely communicating users, allowed the users to play an interactive game cooperatively. The study tested two experimental conditions, characterised by two different modes of synchronisation between the robots that were located locally with each user. In one mode the robots incrementally affected each other’s behaviour, while in the other mode, the robots mirrored each other’s behaviour. This study aimed to identify users’ preferences for robot mediated human-human interactions in these two modes, as well as investigating users’ overall acceptance of such communication media. Findings indicated that users preferred the mirroring mode and that in this pilot study robot assisted remote communication was considered desirable and acceptable to the users. The second platform (AiBone) explored the effects of an autonomous robot on human-human remote communication and studied participants' preferences in comparison with a communication system not involving robots. We developed a platform for remote human-human communication in the context of a collaborative computer game. The exploratory study involved twenty pairs of participants who communicated using video conference software. Participants expressed more social cues and sharing of their game experiences with each other when using the robot. However, analysis of the interactions of the participants with each other and with the robot show that it is difficult for participants to familiarise themselves quickly with the robot while they can perform the same task more efficiently with conventional devices. Finally, our third platform (AIBOStory) was based on a remote interactive story telling software that allowed users to create and share common stories through an integrated, autonomous robot companion acting as a social mediator between two people. The behaviour of the robot was inspired by dog behaviour and used a simple computational memory model. An initial pilot study evaluated the proposed system's use and acceptance by the users. Five pairs of participants were exposed to the system, with the robot acting as a social mediator, and the results suggested an overall positive acceptance response. The main study involved long-term interactions of 20 participants in order to compare their preferences between two modes: using the game enhanced with an autonomous robot and a non-robot mode. The data was analysed using quantitative and qualitative techniques to measure user preference and Human-Robot Interaction. The statistical analysis suggests user preferences towards the robot mode. Furthermore, results indicate that users utilised the memory feature, which was an integral part of the robot’s control architecture, increasingly more as the sessions progressed. Results derived from the three main studies supported our argument that domestic robots could be used as social mediators in remote human-human communications and offered an enhanced experience during their interactions with both robots and each other. Additionally, it was found that the presence of intelligent robots in the communication can increase the number of exhibited social cues between the users and are more preferable compared to conventional interactive devices such as computer keyboard and mouse.

A novel algorithm for fingerprint template formation and matching in automatic fingerprint recognition has been developed. At present, fingerprint is being considered as the dominant biometric trait among all other biometrics due to its wide range of applications in security and access control. Most of the commercially established systems use singularity point (SP) or ‘core’ point for fingerprint indexing and template formation. The efficiency of these systems heavily relies on the detection of the core and the quality of the image itself. The number of multiple SPs or absence of ‘core’ on the image can cause some anomalies in the formation of the template and may result in high False Acceptance Rate (FAR) or False Rejection Rate (FRR). Also the loss of actual minutiae or appearance of new or spurious minutiae in the scanned image can contribute to the error in the matching process. A more sophisticated algorithm is therefore necessary in the formation and matching of templates in order to achieve low FAR and FRR and to make the identification more accurate. The novel algorithm presented here does not rely on any ‘core’ or SP thus makes the structure invariant with respect to global rotation and translation. Moreover, it does not need orientation of the minutiae points on which most of the established algorithm are based. The matching methodology is based on the local features of each minutiae point such as distances to its nearest neighbours and their internal angle. Using a publicly available fingerprint database, the algorithm has been evaluated and compared with other benchmark algorithms. It has been found that the algorithm has performed better compared to others and has been able to achieve an error equal rate of 3.5%.

The visual appearance of an image is a complex function of factors such as scene geometry, material reflectances and textures, illumination, and the properties of the camera used to capture the image. Understanding how these factors interact to produce an image is a fundamental problem in computer vision and graphics. This dissertation examines two aspects of this problem: models of visual appearance that allow us to recover scene properties from images and videos, and tools that allow users to manipulate visual appearance in images and videos in intuitive ways. In particular, we look at these problems in three different applications. First, we propose techniques for compositing images that differ significantly in their appearance. Our framework transfers appearance between images by manipulating the different levels of a multi-scale decomposition of the image. This allows users to create realistic composites with minimal interaction in a number of different scenarios. We also discuss techniques for compositing and replacing facial performances in videos. Second, we look at the problem of creating high-quality still images from low-quality video clips. Traditional multi-image enhancement techniques accomplish this by inverting the camera’s imaging process. Our system incorporates feature weights into these image models to create results that have better resolution, noise, and blur characteristics, and summarize the activity in the video. Finally, we analyze variations in scene appearance caused by changes in lighting. We develop a model for outdoor scene appearance that allows us to recover radiometric and geometric infor- mation about the scene from images. We apply this model to a variety of visual tasks, including color-constancy, background subtraction, shadow detection, scene reconstruction, and camera geo-location. We also show that the appearance of a Lambertian scene can be modeled as a combi- nation of distinct three-dimensional illumination subspaces — a result that leads to novel bounds on scene appearance, and a robust uncalibrated photometric stereo method. / Engineering and Applied Sciences

Developments in high throughput screening and combinatorial chemistry have contributed to the unprecedented success of the pharmaceutical industry over the last twenty years, leading to a multitude of blockbuster compounds that revolutionized treatment for a variety of clinical indications. This success, particularly in drug discovery, has been tempered by an increased number of moieties exhibiting delivery limitations due to molecular structure. One of the most pressing areas of pharmaceutical research today is addressing the reduced aqueous solubility of developmental chemical entities in pharmaceutical pipelines, which has been estimated to affect up to 90% of such compounds. Current technologies have focused on maximizing dissolution rates or equilibrium solubilities of such compounds using platforms such as microemulsions, polymorph engineering, particle size reduction, and complexation. While these technologies have been shown to improve oral bioavailability for a number of compositions, further improvement can be achieved by developing new production and formulation technologies for amorphous systems. Within the frame work of this dissertation, two unique technologies for bioavailability enhancement were investigated; formulation with concentration enhancing polymers to provide extended durations of supersaturation and the development of a novel fusion based solid dispersion production process based on thermo-kinetic mixing, termed KinetiSol® Dispersing, for the production of amorphous solid dispersions. Studies of solid dispersions containing concentration enhancing polymers prepared by ultra rapid freezing showed the ability of these formulations to provide improved oral bioavailability of itraconazole when compared to the currently marketed product, which is a conventional hydrophilic solid dispersion. KinetiSol® Dispersing was also extensively studied within this work and shown to be a viable platform for the production of hydrophilic solid dispersions, plasticizer free solid dispersions and solid dispersions containing heat sensitive active ingredients. In a culminating study, KinetiSol® Dispersing was utilized for the production of amorphous solid dispersions containing concentration enhancing polymers for improved oral bioavailability of itraconazole. Ultimately, this body of work demonstrated that concentration enhancing polymers could provide improved oral bioavailability for poorly water soluble compounds, while KinetiSol® Dispersing could be used for the production of such compositions, thereby presenting novel technologies for addressing future development of poorly water soluble active ingredients. / text

Poor aqueous solubility is one of the greatest barriers for new drug candidates to enter toxicology studies, let alone clinical trials. This thesis focuses on contributing to solving this problem, evaluating the oral toxicity of mesoporous silica particles, and enhancing the apparent solubility and bioavailability of active pharmaceutical ingredients in vitro and in vivo using mesoporous silica particles. Toxicological studies in rats showed that two types of mesoporous silica particles given by oral administration were well tolerated without showing clinical signs of toxicity. Solubility enhancement, including in vivo bioavailability and in vitro intracellular activity, has been evaluated for selected drug compounds. Mesoporous silica was shown to effectively increase drug solubility by stabilizing the amorphous state of APIs, such as itraconazole (anti-fungal), dasatinib (anti-cancer), atazanavir (anti-HIV) and PA-824 (anti-tuberculosis). Itraconazole was successfully loaded into a variety of porous silica materials showing a distinct improvement in the dissolution properties in comparison to non-porous silica materials (and the free drug). Microporosity in SBA-15 particles has advantages in stabilizing the supersaturation state of dasatinib. Small pore sizes show better confinement of atazanavir, contributing to a higher dissolution of the drug compound. In the in vivo animal studies, NFM-1 loaded with atazanavir shows a four-fold increase in bioavailability compared to free crystalline atazanavir. PA-824 has a higher dissolution rate and solubility after loading into AMS-6 mesoporous particles. The loaded particles show similar antibacterial activity as the free PA-824. This thesis aims at highlighting some of the important factors enabling the selection of adequate mesoporous structures to enhance the pharmacokinetic profile of poorly water-soluble compounds, and preparing the scientific framework for uncovering the effects of drug confinement within mesopores of varying structural properties. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Submitted. Paper 3: Submitted. Paper 5: Submitted.</p>

Στην παρούσα διπλωματική αναπτύχθηκε μια μέθοδος ψηφιακής επεξεργασίας σημάτων για ακουστικά σήματα συμβατή με πραγματικού χρόνου επεξεργασία. Αρχικά έγινε περίληψη των λειτουργιών των επεξεργαστών ειδικού σκοπου. Έγινε μελέτη της ανάλυσης στο πεδίο της συχνότητας καθώς και της συνάρτησης συνεκτικότητας. Για τους σκοπούς της διπλωματικής υλοποιήθηκε αλγόριθμος αφαίρεσης θορύβου από σήματα ομιλίας που αξιοποιεί την συνάρτηση συνεκτικότητας και χρησιμοποιεί είσοδο από δύο μικρόφωνα. Ο αλγόριθμος αυτός υλοποιήθηκε και δοκιμάστικε σε μη-πραγματικό χρόνο σε μαθηματικό λογισμικό , καθώς και σε πραγματικό χρόνο σε επεξεργαστή ειδικού σκοπού. / In this thesis, a method of digital signal processing for acoustic signals was developed, compatible with real-time processing. At first, a review of the operations that special purpose digital signal processors feature. We also studied the frequency domain analysis and the coherence function in depth. For the purposes of this thesis an algorithm of noise reduction from speech signals was implemented, that exploits the coherence function and takes two microphone signals as inputs. The algorithm was implemented offline in a mathematical software, as well as real time in a special purpose digital signal processor.

The goal of radiotherapy is to operate within the therapeutic window - delivering doses of ionizing radiation to achieve locoregional tumour control, while minimizing normal tissue toxicity. A greater therapeutic ratio can be achieved by utilizing radiosensitizing agents designed to enhance the effects of radiation at the tumour. Gold nanoparticles (AuNP) represent a novel radiosensitizer with unique and attractive properties. AuNPs enhance local photon interactions, thereby converting photons into localized damaging electrons. Experimental reports of AuNP radiosensitization reveal this enhancement effect to be highly sensitive to irradiation source energy, cell line, and AuNP size, concentration and intracellular localization. This thesis explored the physics and some of the underlying mechanisms behind AuNP radiosensitization. A Monte Carlo simulation approach was developed to investigate the enhanced photoelectric absorption within AuNPs, and to characterize the escaping energy and range of the photoelectric products. Simulations revealed a 10^3 fold increase in the rate of photoelectric absorption using low-energy brachytherapy sources compared to megavolt sources. For low-energy sources, AuNPs released electrons with ranges of only a few microns in the surrounding tissue. For higher energy sources, longer ranged photoelectric products travelled orders of magnitude farther. A novel radiobiological model called the AuNP radiosensitization predictive (ARP) model was developed based on the unique nanoscale energy deposition pattern around AuNPs. The ARP model incorporated detailed Monte Carlo simulations with experimentally determined parameters to predict AuNP radiosensitization. This model compared well to in vitro experiments involving two cancer cell lines (PC-3 and SK-BR-3), two AuNP sizes (5 and 30 nm) and two source energies (100 and 300 kVp). The ARP model was then used to explore the effects of AuNP intracellular localization using 1.9 and 100 nm AuNPs, and 100 and 300 kVp source energies. The impact of AuNP localization was most significant for low-energy sources. At equal mass concentrations, AuNP size did not impact radiosensitization unless the AuNPs were localized in the nucleus. This novel predictive model of AuNP radiosensitization could help define the optimal use of AuNPs in potential clinical strategies by determining therapeutic AuNP concentrations, and recommending when active approaches to cellular accumulation are most beneficial.

The recent invention of Google Glass has prompted me to contemplate how future technologies will affect the way we interact with one another. In this paper, I argue that Google Glass technology is the first sort of technology that will facilitate us to violate our genuine interactions with one another in a face-to-face setting. Once we diminish these types of interactions, we fail to respect one another on a fundamental level and as a result, we fail to genuinely pursue one of the most important classes of meaningful projects in our lives: developing and maintaining relationships.