140 research outputs found

    Speaker Identity Indexing In Audio-Visual Documents

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    International audienceThe identity of persons in audiovisual documents represents very important semantic information for content-based indexing and retrieval. The task of speaker's identity detection can be carried out by exploiting data elements resulting from different modalities (text, image and audio). In this article, we propose an approach for speaker identity indexing in broadcast news using audio content. After a speaker segmentation phase, an identity is given to speech segments by applying linguistic patterns to their transcription from speech recognition. Three types of patterns are used to predict the speaker in the previous, current and next speech segments. Predictions are then propagated to other segments by similarity at the acoustic level. Evaluations have been conducted on part of the TREC 2003 corpus: a speaker identity could be assigned to 53% of the annotated corpus with an 82% precision

    Helicobacter pylori: types of diseases, diagnosis, treatment and causes of therapeutic failure

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    Acute upper gastrointestinal lesions have a multifactorial etiology but, regardless of the cause, they are related to mucosal barrier destruction. Since Helicobacter pylori induces a superficial chronic gastritis with the infiltration of neutrophils in the mucosa, it was speculated that Helicobacter pylori infection could also cause bleeding lesions. The diagnosis, the proper treatment and the revaluation of its effectiveness actually represent the prophylaxis of some diseases such as peptic ulcer, gastric lymphoma or mucosa-associated lymphoid tissue (MALT) and gastric cancer. These diseases and their severe complications are life-threatening for the patient. Periodic renewal of the treatment and knowing the real causes of Helicobacter pylori resistance to various antibiotics must always be understood by the clinician. Although Helicobacter pylori treatment fails in about 20% of cases, moral support of the patient by the clinician, information about possible evolutional complications of Helicobacter pylori infection, and periodic evaluation of the patient during therapy, are important tools on which the therapeutic success depends

    Inelastic Cotunneling Resonances in the Coulomb-Blockade Transport in Donor-Atom Transistors

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    We report finite-bias characteristics of electrical transport through phosphorus donors in silicon nanoscale transistors, in which we observe inelastic-cotunneling current in the Coulomb blockade region. The cotunneling current appears like a resonant-tunneling current peak emerging from the excited state at the crossover between blockade and non-blockade regions. These cotunneling features are unique, since the inelastic-cotunneling currents have so far been reported either as a broader hump or as a continuous increment of current. This finding is ascribed purely due to excitation-related inelastic cotunneling involving the ground and excited states. Theoretical calculations were performed for a two-level quantum dot, supporting our experimental observation

    Neuropsychological symptoms related to the COVID-19 pandemic experienced by the general population and particularly by the healthcare personnel

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    Undoubtedly, the outbreak of COVID-19 still represents an overanxious event for both society and population. The fear of getting infected is ubiquitous in the time of the pandemic. The population presented worrying thoughts related to the fact that the health care system was not able to provide enough services during the COVID-19 pandemic. The number of the hospital beds and ventilators was insufficient in order to ensure enough care, considering the increased number of COVID-19 cases that were admitted to the hospitals. Furthermore, people were fearful about the possibility of the global economy becoming decimated. The fright and also the feelings of anxiety related to the COVID-19 pandemic can become overpowering and create negative psychological states. In addition, mental health can be affected and influenced during outbreaks of infectious diseases and can be related to the misconception of symptoms, for example perception related phenomenon and corporal modifications. The population that could experiment these feelings, could instantly relate them to the coronavirus infection and express furthermore unpleasant sensations, in connection to more expressed anxiety and fear. Particularly affected were the healthcare workers of the medical system, who were the main combatants in this pandemic. The neuropsychological problems were difficult to avoid by the general population and this became even more difficult to be dealt with by the medical personnel

    Observation of Photovoltaic Effect and Single-photon Detection in Nanowire Silicon Pn-junction

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    We  study  nanowire  silicon  pin  and  pn-junctions  at  room  and  low  temperature.  Photovoltaic  effects  are  observed  for both devices at room temperature. At low temperature, nanowire pn-junction devices show their ability to detect single photon. This ability was not been observed for pin devices. Phosphorus-boron dopant cluster in the depletion region is considered  to  have  the  main  role  for  single-photon  detection  capability.  Fundamental  mechanism  of  dopant-based single-photon detection in nanowire pn-junction is described in details

    Atom devices based on single dopants in silicon nanostructures

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    Silicon field-effect transistors have now reached gate lengths of only a few tens of nanometers, containing a countable number of dopants in the channel. Such technological trend brought us to a research stage on devices working with one or a few dopant atoms. In this work, we review our most recent studies on key atom devices with fundamental structures of silicon-on-insulator MOSFETs, such as single-dopant transistors, preliminary memory devices, single-electron turnstile devices and photonic devices, in which electron tunneling mediated by single dopant atoms is the essential transport mechanism. Furthermore, observation of individual dopant potential in the channel by Kelvin probe force microscopy is also presented. These results may pave the way for the development of a new device technology, i.e., single-dopant atom electronics

    Observation of Photovoltaic Effect and Single-photon Detection in Nanowire Silicon pn-junction

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    We  study  nanowire  silicon  pin  and  pn-junctions  at  room  and  low  temperature.  Photovoltaic  effects  are  observed  for both devices at room temperature. At low temperature, nanowire pn-junction devices show their ability to detect single photon. This ability was not been observed for pin devices. Phosphorus-boron dopant cluster in the depletion region is considered  to  have  the  main  role  for  single-photon  detection  capability.  Fundamental  mechanism  of  dopant-based single-photon detection in nanowire pn-junction is described in details.Keywords: dopant cluster, nanowire pn-junction, single dopant, single photo

    Functional model for determining the optimal duration of use of fixed assets

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    The purpose of this paper was to present a functional model for determining the duration of use of fixed assets based on the relationship between the average fixed cost of depreciation of the fixed medium and the opportunity cost determined by the market of the respective product. The objectives of the paper included: 1. determining the correlation between the duration of use, the total distance travelled and the price of fixed assets; 2. determining the optimal duration of use of the fixed assets based on the relationship between the average fixed cost and the opportunity cost. In order to determine the optimal duration of use, the minimum marginal cost of depreciation was calculated as the ratio of the difference between the prices between moments n and n + 1 and the length or kilometres travelled in the range n and n + 1. Also, the marginal opportunity cost for the remaining transport capacity to be used was determined starting from the hypothesis that the market assigns a price to a usable capacity and to a capacity too old to be used, the price is nil. As a result, we identified the average price for the maximum duration or distance of use. The marginal opportunity cost was determined as the ratio between the price at one point and the remaining difference to be used by kilometres or old. The remaining difference to be used was calculated as the difference between the maximum duration that can be used and the time at time i or the maximum distance travelled and the distance travelled at price i. The average cost with the depreciation of the fixed means analysed is determined by the distance travelled and its age. The proposed model allows to determine an optimal duration of use of the fixed means according to their age and the transport distance. This model can be easily adapted to other types of fixed assets and the quality of the results is given by the existence of a significant number of data on their selling prices

    Physics of Strongly-coupled Dopant-atoms in Nanodevices

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    In silicon nanoscale transistors, dopant atoms can significantly affect the transport characteristics, in particular at low temperatures. Investigation of coupling between neighboring dopants in such devices is essential in defining the properties for transport. In this work, we present an overview of different regimes of inter-dopant coupling, controlled by doping concentration and a selective doping process. Tunneling-transport spectroscopy can reveal the fundamental physics of isolated dopants in comparison with strongly-coupled dopants. In addition, observations of surface potential for Si nano-transistors can provide direct access to understanding the behavior of coupled dopants
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