946 resultados para Fast virtual stenting method


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This study is dedicated to search engine marketing (SEM). It aims for developing a business model of SEM firms and to provide explicit research of trustworthy practices of virtual marketing companies. Optimization is a general term that represents a variety of techniques and methods of the web pages promotion. The research addresses optimization as a business activity, and it explains its role for the online marketing. Additionally, it highlights issues of unethical techniques utilization by marketers which created relatively negative attitude to them on the Internet environment. Literature insight combines in the one place both technical and economical scientific findings in order to highlight technological and business attributes incorporated in SEM activities. Empirical data regarding search marketers was collected via e-mail questionnaires. 4 representatives of SEM companies were engaged in this study to accomplish the business model design. Additionally, the fifth respondent was a representative of the search engine portal, who provided insight on relations between search engines and marketers. Obtained information of the respondents was processed qualitatively. Movement of commercial organizations to the online market increases demand on promotional programs. SEM is the largest part of online marketing, and it is a prerogative of search engines portals. However, skilled users, or marketers, are able to implement long-term marketing programs by utilizing web page optimization techniques, key word consultancy or content optimization to increase web site visibility to search engines and, therefore, user’s attention to the customer pages. SEM firms are related to small knowledge-intensive businesses. On the basis of data analysis the business model was constructed. The SEM model includes generalized constructs, although they represent a wider amount of operational aspects. Constructing blocks of the model includes fundamental parts of SEM commercial activity: value creation, customer, infrastructure and financial segments. Also, approaches were provided on company’s differentiation and competitive advantages evaluation. It is assumed that search marketers should apply further attempts to differentiate own business out of the large number of similar service providing companies. Findings indicate that SEM companies are interested in the increasing their trustworthiness and the reputation building. Future of the search marketing is directly depending on search engines development.

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Deep cannulation is a prerequisite for successful endoscopic retrograde cholangiopancreatography (ERCP) procedures. Of the biliary procedures, stenting is one of the most common. This study was carried out to investigate current and controversial issues regarding biliary cannulation and stenting. The double guidewire (DGW) technique was studied to analyze its safety and feasibility in biliary cannulation as a single procedure and as a part of the novel three-step cannulation protocol. Female gender was evaluated in regard to difficult cannulation. The use of an angled and a straight tipped guidewire in biliary cannulation was studied in a prospective, randomized trial. Additionally, the patency of the novel antireflux plastic biliary stent was compared to the patency of the conventional plastic biliary stent in a prospective, randomized setting. The DGW method seems safe and feasible as an alternative cannulation technique in biliary cannulation. Female gender was not associated significantly with difficult biliary cannulation in our study, although the cannulation times seemed to be longer and the alternative cannulation techniques seemed to be needed more often in females than males. According to the results of this thesis, an angled tipped guidewire may facilitate biliary cannulation. In controversy to the previous result presented in the literature, the antireflux plastic biliary stent tested herein should not be used, as the patency of the stent was significantly shorter compared to the conventional plastic stent.

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This study discusses the procedures of value co-creation that persist in gaming industry. The purpose of this study was to identify the procedures that persist in current video gaming industry which answers the main research problem how value is co-created in video gaming industry followed by three sub questions: (i) What is value co-creation in gaming industry? (ii) Who participates in value co-creation in gaming industry? (iii) What are the procedures that are involved in value co-creation in gaming industry? The theoretical background of the study consists of literature relating to the theory of marketing i.e., notion of value, conventional understanding of value creation, value chain, co-creation approach, co-production approach. The research adopted qualitative research approach. As a platform of relationship researcher used web 2.0 tool interface. Data were collected from the social networks and netnography method was applied for analyzing them. Findings show that customer and company both co-create optimum level of value while they interact with each other and within the customers as well. However mostly the C2C interaction, discussions and dialogues threads that emerged around the main discussion facilitated to co-create value. In this manner, companies require exploiting and further motivating, developing and supporting the interactions between customers participating in value creation. Hierarchy of value co-creation processes is the result derived from the identified challenges of value co-creation approach and discussion forums data analysis. Overall three general sets and seven topics were found that explored the phenomenon of customer to customer (C2C) and business to customer (B2C) interaction/debating for value co-creation through user generated contents. These topics describe how gamer contributes and interacts in co-creating value along with companies. A methodical quest in current research literature acknowledged numerous evolving flows of value in this study. These are general management perspective, new product development and innovation, virtual customer environment, service science and service dominant logic. Overall the topics deliver various realistic and conceptual implications for using and handling gamers in social networks for augmenting customers’ value co-creation process.

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R,S-sotalol, a ß-blocker drug with class III antiarrhythmic properties, is prescribed to patients with ventricular, atrial and supraventricular arrhythmias. A simple and sensitive method based on HPLC-fluorescence is described for the quantification of R,S-sotalol racemate in 500 µl of plasma. R,S-sotalol and its internal standard (atenolol) were eluted after 5.9 and 8.5 min, respectively, from a 4-micron C18 reverse-phase column using a mobile phase consisting of 80 mM KH2PO4, pH 4.6, and acetonitrile (95:5, v/v) at a flow rate of 0.5 ml/min with detection at lex = 235 nm and lem = 310 nm, respectively. This method, validated on the basis of R,S-sotalol measurements in spiked blank plasma, presented 20 ng/ml sensitivity, 20-10,000 ng/ml linearity, and 2.9 and 4.8% intra- and interassay precision, respectively. Plasma sotalol concentrations were determined by applying this method to investigate five high-risk patients with atrial fibrillation admitted to the Emergency Service of the Medical School Hospital, who received sotalol, 160 mg po, as loading dose. Blood samples were collected from a peripheral vein at zero, 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0, 8.0, 12.0 and 24.0 h after drug administration. A two-compartment open model was applied. Data obtained, expressed as mean, were: CMAX = 1230 ng/ml, TMAX = 1.8 h, AUCT = 10645 ng h-1 ml-1, Kab = 1.23 h-1, a = 0.95 h-1, ß = 0.09 h-1, t(1/2)ß = 7.8 h, ClT/F = 3.94 ml min-1 kg-1, and Vd/F = 2.53 l/kg. A good systemic availability and a fast absorption were obtained. Drug distribution was reduced to the same extent in terms of total body clearance when patients and healthy volunteers were compared, and consequently elimination half-life remained unchanged. Thus, the method described in the present study is useful for therapeutic drug monitoring purposes, pharmacokinetic investigation and pharmacokinetic-pharmacodynamic sotalol studies in patients with tachyarrhythmias.

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Virtual environments and real-time simulators (VERS) are becoming more and more important tools in research and development (R&D) process of non-road mobile machinery (NRMM). The virtual prototyping techniques enable faster and more cost-efficient development of machines compared to use of real life prototypes. High energy efficiency has become an important topic in the world of NRMM because of environmental and economic demands. The objective of this thesis is to develop VERS based methods for research and development of NRMM. A process using VERS for assessing effects of human operators on the life-cycle efficiency of NRMM was developed. Human in the loop simulations are ran using an underground mining loader to study the developed process. The simulations were ran in the virtual environment of the Laboratory of Intelligent Machines of Lappeenranta University of Technology. A physically adequate real-time simulation model of NRMM was shown to be reliable and cost effective in testing of hardware components by the means of hardware-in-the-loop (HIL) simulations. A control interface connecting integrated electro-hydraulic energy converter (IEHEC) with virtual simulation model of log crane was developed. IEHEC consists of a hydraulic pump-motor and an integrated electrical permanent magnet synchronous motorgenerator. The results show that state of the art real-time NRMM simulators are capable to solve factors related to energy consumption and productivity of the NRMM. A significant variation between the test drivers is found. The results show that VERS can be used for assessing human effects on the life-cycle efficiency of NRMM. HIL simulation responses compared to that achieved with conventional simulation method demonstrate the advances and drawbacks of various possible interfaces between the simulator and hardware part of the system under study. Novel ideas for arranging the interface are successfully tested and compared with the more traditional one. The proposed process for assessing the effects of operators on the life-cycle efficiency will be applied for wider group of operators in the future. Driving styles of the operators can be analysed statistically from sufficient large result data. The statistical analysis can find the most life-cycle efficient driving style for the specific environment and machinery. The proposed control interface for HIL simulation need to be further studied. The robustness and the adaptation of the interface in different situations must be verified. The future work will also include studying the suitability of the IEHEC for different working machines using the proposed HIL simulation method.

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The application of pulp and paper mill (PPM) sludge in agriculture and forestry has been acknowledged as soil amendments and a plant nutrient source. The main objectives of this study were to evaluate the total cost of the use of recycled nutrients from PPM sludge in fast growing pulpwood production, and the financial profitability of fast growing pulpwood production with the use of these recycled nutrients. The investment and production costs of fast growing pulpwood plantation were directly acquired from a previous research, while the other data was compiled through different studies. The total cost of the use of PPM sludge was evaluated based on assumed factors. Discounted cash flow method was used to evaluate the financial profitability, using NPV and IRR as indicators. The results of estimated sludge nutrient contents were 16.2 g N, 2.9 g P, and 2.4 g K kg-1 of dry sludge. The sludge application rate was estimated at 1.36 Mg/ha in the first year. The total cost of the use of PPM sludge involved transport and spreading cost of US$49.15/dry ton. The fertilization cost applied in the financial model was designed in 3 different options and their results were as follows: option (1) was taken directly from the reference research (US$97/ha); option (2) was the use of sludge alone (US$66.75/ha); and option (3) was the use of sludge and TSP fertilizer (US$83.80/ha). The average NPV without discounting was US$248,180 while the IRRs ranged between approximately 3-4% with an average of 3.63%. Although option (2) and (3) contributed to higher IRRs compared to option (1), this increase was still not significant as the IRR was not sensitive to the total fertilization cost. The advantages are that this practice can be performed at a lower cost and the application rate can be still increased if necessary. It is better for forest plantations compared to agriculture and consequently supports reforestation program. In addition, it can be similarly applied in wood biomass production. A disadvantage is that the IRRs were not very favorable compared to the criterion of 11%. The sludge high in C:N ratio can cause nitrogen immobilization, and regulatory concerns may restrict and complicate the use of sludge landspreading and contribute to additional costs and processes.

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The autonomic nervous system plays an important role in physiological and pathological conditions, and has been extensively evaluated by parametric and non-parametric spectral analysis. To compare the results obtained with fast Fourier transform (FFT) and the autoregressive (AR) method, we performed a comprehensive comparative study using data from humans and rats during pharmacological blockade (in rats), a postural test (in humans), and in the hypertensive state (in both humans and rats). Although postural hypotension in humans induced an increase in normalized low-frequency (LFnu) of systolic blood pressure, the increase in the ratio was detected only by AR. In rats, AR and FFT analysis did not agree for LFnu and high frequency (HFnu) under basal conditions and after vagal blockade. The increase in the LF/HF ratio of the pulse interval, induced by methylatropine, was detected only by FFT. In hypertensive patients, changes in LF and HF for systolic blood pressure were observed only by AR; FFT was able to detect the reduction in both blood pressure variance and total power. In hypertensive rats, AR presented different values of variance and total power for systolic blood pressure. Moreover, AR and FFT presented discordant results for LF, LFnu, HF, LF/HF ratio, and total power for pulse interval. We provide evidence for disagreement in 23% of the indices of blood pressure and heart rate variability in humans and 67% discordance in rats when these variables are evaluated by AR and FFT under physiological and pathological conditions. The overall disagreement between AR and FFT in this study was 43%.

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Abstract An accurate, reliable and fast multianalyte/multiclass ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method was developed and validated for the simultaneous analysis of 23 pharmaceuticals, belonging to different classes amphenicols, sulfonamides, tetracyclines, in honey samples. The method developed consists of ultrasonic extraction followed by UPLC–ESI–MS/MS with electrospray ionization in both positive mode and negative mode. The influence of the extraction solvents and mobile phase composition on the sensitivity of the method, and the optimum conditions for sample weight and extraction temperature in terms of analyte recovery were extensively studied. The identification of antibiotics is fulfilled by simultaneous use of chromatographic separation using an Acquity BEH C18 (100 mm x 2.1 mm, 1.7 µm) analytical column with a gradient elution of mobile phases and tandem mass spectrometry with an electrospray ionization. Finally, the method developed was applied to the determination of target analytes in honey samples obtained from the local markets and several beekeepers in Muğla, Turkey. Ultrasonic-extraction of pharmaceuticals from honey samples is a well-established technique by UPLC–ESI–MS/MS, the uniqueness of this study lies in the simultaneous determination of a remarkable number of compounds belonging to 23 drug at the sub-nanogram per kilogram level.

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Bien que les champignons soient régulièrement utilisés comme modèle d'étude des systèmes eucaryotes, leurs relations phylogénétiques soulèvent encore des questions controversées. Parmi celles-ci, la classification des zygomycètes reste inconsistante. Ils sont potentiellement paraphylétiques, i.e. regroupent de lignées fongiques non directement affiliées. La position phylogénétique du genre Schizosaccharomyces est aussi controversée: appartient-il aux Taphrinomycotina (précédemment connus comme archiascomycetes) comme prédit par l'analyse de gènes nucléaires, ou est-il plutôt relié aux Saccharomycotina (levures bourgeonnantes) tel que le suggère la phylogénie mitochondriale? Une autre question concerne la position phylogénétique des nucléariides, un groupe d'eucaryotes amiboïdes que l'on suppose étroitement relié aux champignons. Des analyses multi-gènes réalisées antérieurement n'ont pu conclure, étant donné le choix d'un nombre réduit de taxons et l'utilisation de six gènes nucléaires seulement. Nous avons abordé ces questions par le biais d'inférences phylogénétiques et tests statistiques appliqués à des assemblages de données phylogénomiques nucléaires et mitochondriales. D'après nos résultats, les zygomycètes sont paraphylétiques (Chapitre 2) bien que le signal phylogénétique issu du jeu de données mitochondriales disponibles est insuffisant pour résoudre l'ordre de cet embranchement avec une confiance statistique significative. Dans le Chapitre 3, nous montrons à l'aide d'un jeu de données nucléaires important (plus de cent protéines) et avec supports statistiques concluants, que le genre Schizosaccharomyces appartient aux Taphrinomycotina. De plus, nous démontrons que le regroupement conflictuel des Schizosaccharomyces avec les Saccharomycotina, venant des données mitochondriales, est le résultat d'un type d'erreur phylogénétique connu: l'attraction des longues branches (ALB), un artéfact menant au regroupement d'espèces dont le taux d'évolution rapide n'est pas représentatif de leur véritable position dans l'arbre phylogénétique. Dans le Chapitre 4, en utilisant encore un important jeu de données nucléaires, nous démontrons avec support statistique significatif que les nucleariides constituent le groupe lié de plus près aux champignons. Nous confirmons aussi la paraphylie des zygomycètes traditionnels tel que suggéré précédemment, avec support statistique significatif, bien que ne pouvant placer tous les membres du groupe avec confiance. Nos résultats remettent en cause des aspects d'une récente reclassification taxonomique des zygomycètes et de leurs voisins, les chytridiomycètes. Contrer ou minimiser les artéfacts phylogénétiques telle l'attraction des longues branches (ALB) constitue une question récurrente majeure. Dans ce sens, nous avons développé une nouvelle méthode (Chapitre 5) qui identifie et élimine dans une séquence les sites présentant une grande variation du taux d'évolution (sites fortement hétérotaches - sites HH); ces sites sont connus comme contribuant significativement au phénomène d'ALB. Notre méthode est basée sur un test de rapport de vraisemblance (likelihood ratio test, LRT). Deux jeux de données publiés précédemment sont utilisés pour démontrer que le retrait graduel des sites HH chez les espèces à évolution accélérée (sensibles à l'ALB) augmente significativement le support pour la topologie « vraie » attendue, et ce, de façon plus efficace comparée à d'autres méthodes publiées de retrait de sites de séquences. Néanmoins, et de façon générale, la manipulation de données préalable à l'analyse est loin d’être idéale. Les développements futurs devront viser l'intégration de l'identification et la pondération des sites HH au processus d'inférence phylogénétique lui-même.

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L'interface cerveau-ordinateur (ICO) décode les signaux électriques du cerveau requise par l’électroencéphalographie et transforme ces signaux en commande pour contrôler un appareil ou un logiciel. Un nombre limité de tâches mentales ont été détectés et classifier par différents groupes de recherche. D’autres types de contrôle, par exemple l’exécution d'un mouvement du pied, réel ou imaginaire, peut modifier les ondes cérébrales du cortex moteur. Nous avons utilisé un ICO pour déterminer si nous pouvions faire une classification entre la navigation de type marche avant et arrière, en temps réel et en temps différé, en utilisant différentes méthodes. Dix personnes en bonne santé ont participé à l’expérience sur les ICO dans un tunnel virtuel. L’expérience fut a était divisé en deux séances (48 min chaque). Chaque séance comprenait 320 essais. On a demandé au sujets d’imaginer un déplacement avant ou arrière dans le tunnel virtuel de façon aléatoire d’après une commande écrite sur l'écran. Les essais ont été menés avec feedback. Trois électrodes ont été montées sur le scalp, vis-à-vis du cortex moteur. Durant la 1re séance, la classification des deux taches (navigation avant et arrière) a été réalisée par les méthodes de puissance de bande, de représentation temporel-fréquence, des modèles autorégressifs et des rapports d’asymétrie du rythme β avec classificateurs d’analyse discriminante linéaire et SVM. Les seuils ont été calculés en temps différé pour former des signaux de contrôle qui ont été utilisés en temps réel durant la 2e séance afin d’initier, par les ondes cérébrales de l'utilisateur, le déplacement du tunnel virtuel dans le sens demandé. Après 96 min d'entrainement, la méthode « online biofeedback » de la puissance de bande a atteint une précision de classification moyenne de 76 %, et la classification en temps différé avec les rapports d’asymétrie et puissance de bande, a atteint une précision de classification d’environ 80 %.

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L’observation de l’exécution d’applications JavaScript est habituellement réalisée en instrumentant une machine virtuelle (MV) industrielle ou en effectuant une traduction source-à-source ad hoc et complexe. Ce mémoire présente une alternative basée sur la superposition de machines virtuelles. Notre approche consiste à faire une traduction source-à-source d’un programme pendant son exécution pour exposer ses opérations de bas niveau au travers d’un modèle objet flexible. Ces opérations de bas niveau peuvent ensuite être redéfinies pendant l’exécution pour pouvoir en faire l’observation. Pour limiter la pénalité en performance introduite, notre approche exploite les opérations rapides originales de la MV sous-jacente, lorsque cela est possible, et applique les techniques de compilation à-la-volée dans la MV superposée. Notre implémentation, Photon, est en moyenne 19% plus rapide qu’un interprète moderne, et entre 19× et 56× plus lente en moyenne que les compilateurs à-la-volée utilisés dans les navigateurs web populaires. Ce mémoire montre donc que la superposition de machines virtuelles est une technique alternative compétitive à la modification d’un interprète moderne pour JavaScript lorsqu’appliqué à l’observation à l’exécution des opérations sur les objets et des appels de fonction.

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Demonstration videos can be found on fr.linkedin.com/in/doriangomez/

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Ce mémoire s'intéresse à la reconstruction d'un modèle 3D à partir de plusieurs images. Le modèle 3D est élaboré avec une représentation hiérarchique de voxels sous la forme d'un octree. Un cube englobant le modèle 3D est calculé à partir de la position des caméras. Ce cube contient les voxels et il définit la position de caméras virtuelles. Le modèle 3D est initialisé par une enveloppe convexe basée sur la couleur uniforme du fond des images. Cette enveloppe permet de creuser la périphérie du modèle 3D. Ensuite un coût pondéré est calculé pour évaluer la qualité de chaque voxel à faire partie de la surface de l'objet. Ce coût tient compte de la similarité des pixels provenant de chaque image associée à la caméra virtuelle. Finalement et pour chacune des caméras virtuelles, une surface est calculée basée sur le coût en utilisant la méthode de SGM. La méthode SGM tient compte du voisinage lors du calcul de profondeur et ce mémoire présente une variation de la méthode pour tenir compte des voxels précédemment exclus du modèle par l'étape d'initialisation ou de creusage par une autre surface. Par la suite, les surfaces calculées sont utilisées pour creuser et finaliser le modèle 3D. Ce mémoire présente une combinaison innovante d'étapes permettant de créer un modèle 3D basé sur un ensemble d'images existant ou encore sur une suite d'images capturées en série pouvant mener à la création d'un modèle 3D en temps réel.

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The focus of this work is to provide authentication and confidentiality of messages in a swift and cost effective manner to suit the fast growing Internet applications. A nested hash function with lower computational and storage demands is designed with a view to providing authentication as also to encrypt the message as well as the hash code using a fast stream cipher MAJE4 with a variable key size of 128-bit or 256-bit for achieving confidentiality. Both nested Hash function and MAJE4 stream cipher algorithm use primitive computational operators commonly found in microprocessors; this makes the method simple and fast to implement both in hardware and software. Since the memory requirement is less, it can be used for handheld devices for security purposes.

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In this paper, a novel fast method for modeling mammograms by deterministic fractal coding approach to detect the presence of microcalcifications, which are early signs of breast cancer, is presented. The modeled mammogram obtained using fractal encoding method is visually similar to the original image containing microcalcifications, and therefore, when it is taken out from the original mammogram, the presence of microcalcifications can be enhanced. The limitation of fractal image modeling is the tremendous time required for encoding. In the present work, instead of searching for a matching domain in the entire domain pool of the image, three methods based on mean and variance, dynamic range of the image blocks, and mass center features are used. This reduced the encoding time by a factor of 3, 89, and 13, respectively, in the three methods with respect to the conventional fractal image coding method with quad tree partitioning. The mammograms obtained from The Mammographic Image Analysis Society database (ground truth available) gave a total detection score of 87.6%, 87.6%, 90.5%, and 87.6%, for the conventional and the proposed three methods, respectively.