26 research outputs found

    Dynamic Biomechanical Analysis of Vocal Folds Using Pipette Aspiration Technique

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    The voice producing process is a complex interplay between glottal pressure, vocal folds, their elasticity and tension. The material properties of vocal folds are still insufficiently studied, because the determination of material properties in soft tissues is often difficult and connected to extensive experimental setups. To shed light on this less researched area, in this work, a dynamic pipette aspiration technique is utilized to measure the elasticity in a frequency range of 100–1000 Hz. The complex elasticity could be assessed with the phase shift between exciting pressure and tissue movement. The dynamic pipette aspiration setup has been miniaturized with regard to a future in-vivo application. The techniques were applied on 3 different porcine larynges 4 h and 1 d postmortem, in order to investigate the deterioration of the tissue over time and analyze correlation in elasticity values between vocal fold pairs. It was found that vocal fold pairs do have different absolute elasticity values but similar trends. This leads to the assumption that those trends are more important for phonation than having same absolute values

    A Quasi-Static Quantitative Ultrasound Elastography Algorithm Using Optical Flow

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    Ultrasound elastography is a constantly developing imaging technique which is capable of displaying the elastic properties of tissue. The measured characteristics could help to refine physiological tissue models, but also indicate pathological changes. Therefore, elastography data give valuable insights into tissue properties. This paper presents an algorithm that measures the spatially resolved Young’s modulus of inhomogeneous gelatin phantoms using a CINE sequence of a quasi-static compression and a load cell measuring the compressing force. An optical flow algorithm evaluates the resulting images, the stresses and strains are computed, and, conclusively, the Young’s modulus and the Poisson’s ratio are calculated. The whole algorithm and its results are evaluated by a performance descriptor, which determines the subsequent calculation and gives the user a trustability index of the modulus estimation. The algorithm shows a good match between the mechanically measured modulus and the elastography result—more precisely, the relative error of the Young’s modulus estimation with a maximum error 35%. Therefore, this study presents a new algorithm that is capable of measuring the elastic properties of gelatin specimens in a quantitative way using only the image data. Further, the computation is monitored and evaluated by a performance descriptor, which measures the trustability of the results

    SARS-CoV-2, a Threat to Privacy?

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    The global SARS-CoV-2 pandemic is currently putting a massive strain on the world's critical infrastructures. With healthcare systems and internet service providers already struggling to provide reliable service, some operators may, intentionally or unintentionally, lever out privacy-protecting measures to increase their system's efficiency in fighting the virus. Moreover, though it may seem all encouraging to see the effectiveness of authoritarian states in battling the crisis, we, the authors of this paper, would like to raise the community's awareness towards developing more effective means in battling the crisis without the need to limit fundamental human rights. To analyze the current situation, we are discussing and evaluating the steps corporations and governments are taking to condemn the virus by applying established privacy research

    A procedural approach to automate the manual design process in analog integrated circuit design

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    This paper presents a novel approach to automating the design of analog integrated circuits: (1) the Expert Design Plan (EDP), a procedural generator, and (2) the EDP Language, a high-level description language for writing an EDP. An EDP is a parameterizable, executable script, which reproduces a designer’s course of action when designing a circuit. Thus, an EDP formalizes the design expert’s knowledge-based strategy and makes it reusable. Since it is essential that an EDP represents a circuit designers’ way of thinking and working as close as possible, the designers themselves should be enabled to create the EDP. Therefore, our approach provides a input method through a domain-specific language called EDP Language (EDPL). Using this language is intuitive and requires no special training. In an exemplary implementation of our approach, a common-source amplifier is automatically sized using a set of only 10 instructions. Even in the first usage our EDP approach has appeared to be more efficient than the manual sizing process

    Kinetic Façade, Theme Pavilion Expo 2012 Yeosu, South Korea

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    Conference book please see: http://www.buildingcentre.co.uk/events/event_diary_details.asp?id=863 and http://vimeo.com/6082155

    Comparison of Multiple Moisture-Measurement Techniques Applied on Biological Tissue

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    Abstract This papers presents a measurement setup which combines three different methods indicating the moisture fraction of a sample. This is managed by measuring the weight, the absolute electrical impedance with a harmonic excitation between 10 Hz to 1000 Hz and the surface reflectance of the sample with a spectroscope between 160nm to 1100nm. The measurements are carried out over 50 h every 5 min using a piece of porcine meat. The results show clear evidences that the dehydration occurs on the surface until the water inside is diffused to the surface completely. This can be seen on significant wavelengths of absorption bands in the reflected spectrum like 540nm, 575nm and 970nm (oxyhaemobglobin and water) and in the impedance measurement that are both set into ratio with the weight loss of the sample.</jats:p
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