6,921 research outputs found

    The application of clinical simulation in crisis management training.

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    Since it was first introduced more than 30 years ago, clinical simulation has become a popular tool for medical training, particularly in crisis management. The modern high-fidelity patient simulator consists of a whole-body mannequin with integrated electronic patient monitoring; it is controlled by computers capable of simulating numerous clinical scenarios and patient characteristics, and reacting to various interventions appropriately. Simulator training is theoretically superior to conventional training in management of rare crisis situations, as it allows unlimited practice in a safe yet familiar environment. Training in clinical skills can be developed, together with competency in crisis management behaviours such as leadership and communication skills. Although there is evidence demonstrating the popularity, reliability, and validity of simulator training, its superiority over conventional training has not been proven, and research in this area is required.published_or_final_versio

    Reproducibility of transmission line measurement of bipolar I-V characteristics of MOSFET's

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    Reproducibility of transmission line (TL) measurement of bipolar current-voltage (I-V) characteristics of grounded gate MOSFET's has been examined. It is observed that the reproducibility is related to the duration of the pulses generated by the transmission line, and a longer pulse duration gives a better reproducibility. For a short pulse duration, it is more difficult to reproduce the I-V characteristics in the triggering region than in other regions (i.e., the pretriggering and snapback regions).published_or_final_versio

    Interface trap generation by FN injection under dynamic oxide field stress

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    Interface trap generation under dynamic (bipolar and unipolar) and dc oxide field stress has been investigated with the charge pumping technique. It is observed that regardless of stress type, whether dc or dynamic (bipolar or unipolar), and the polarity of stress voltage, interface trap generation starts to occur at the voltage at which Fowler-Nordheim (FN) tunneling through the oxide starts to build up. For positive voltage, interface trap generation is attributed to the recombination of trapped holes with electrons and to the bond breaking by the hydrogen (H and H+) released during stressing. For negative voltage, in addition to these two mechanisms, the bond breaking by energetic electrons may also contribute to interface trap generation. The frequency dependence of interface trap generation is also investigated. Interface trap generation is independent of stressing frequency for unipolar stress but it shows a frequency dependence for bipolar stress. ©1998 IEEE.published_or_final_versio

    Maximizing the network outage rate for fast fluid antenna multiple access systems

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    Using reconfigurable fluid antennas, it is possible to have a software-controlled position-tuneable antenna to realize spatial diversity and multiplexing gains that are previously only possible using multiple antennas. Recent results illustrated that fast fluid antenna multiple access (f-FAMA) which always tunes the antenna to the position for maximum signal-to-interference ratio (SIR) on a symbol-by-symbol basis, could support hundreds of users on the same radio channel, all by a single fluid antenna at each user without complex coordination and optimization. The network outage rate, nevertheless, depends on the SIR threshold chosen for each user. Motivated by this, this paper adopts a first-order approximation to obtain the outage probability expression from which a closed-form solution is derived for optimizing the SIR threshold in maximizing the network outage rate. Moreover, a closed-form expression is provided to estimate the number of users in the f-FAMA network in which the outage rate begins to plateau. Numerical results show that the proposed SIR threshold achieves near-maximal outage rate performance

    Exercise-Induced Changes in Exhaled NO Differentiates Asthma With or Without Fixed Airway Obstruction From COPD With Dynamic Hyperinflation.

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    Asthmatic patients with fixed airway obstruction (FAO) and patients with chronic obstructive pulmonary disease (COPD) share similarities in terms of irreversible pulmonary function impairment. Exhaled nitric oxide (eNO) has been documented as a marker of airway inflammation in asthma, but not in COPD. To examine whether the basal eNO level and the change after exercise may differentiate asthmatics with FAO from COPD, 27 normal subjects, 60 stable asthmatics, and 62 stable COPD patients were studied. Asthmatics with FAO (n = 29) were defined as showing a postbronchodilator FEV(1)/forced vital capacity (FVC) ≤70% and FEV(1) less than 80% predicted after inhaled salbutamol (400 μg). COPD with dynamic hyperinflation (n = 31) was defined as a decrease in inspiratory capacity (ΔIC%) after a 6 minute walk test (6MWT). Basal levels of eNO were significantly higher in asthmatics and COPD patients compared to normal subjects. The changes in eNO after 6MWT were negatively correlated with the percent change in IC (r = −0.380, n = 29, P = 0.042) in asthmatics with FAO. Their levels of basal eNO correlated with the maximum mid-expiratory flow (MMEF % predicted) before and after 6MWT. In COPD patients with air-trapping, the percent change of eNO was positively correlated to ΔIC% (rs = 0.404, n = 31, P = 0.024). We conclude that asthma with FAO may represent residual inflammation in the airways, while dynamic hyperinflation in COPD may retain NO in the distal airspace. eNO changes after 6MWT may differentiate the subgroups of asthma or COPD patients and will help toward delivery of individualized therapy for airflow obstruction

    Closed-form expressions for spatial correlation parameters for performance analysis of fluid antenna systems

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    The emerging fluid antenna technology enables a high-density positionswitchable antenna in a small space to obtain enormous performance gains for wireless communications. To understand the theoretical performance of fluid antenna systems, it is important to account for the strong spatial correlation over the different positions (referred to as ‘ports’). Previous works used a classical, generalised correlation model to characterise the channel correlation among the ports but were limited by the lack of degree of freedom of the model to imitate the correlation structures in an actual antenna. In this letter, it is proposed to use a common correlation parameter and to choose it by setting the correlation coefficient of any two ports to be the same as the average correlation coefficient of an actual fluid antenna taking up a linear space. A closedform expression for the spatial correlation parameter is first derived assuming that the number of ports is large, and it is illustrated that the correlation parameter depends only on the size of the fluid antenna but not the port density. Simpler expressions are then obtained for small and large sizes of fluid antenna. The resulting model is finally used to study the performance of fluid antenna systems. Simulation results based on the proposed model are provided to confirm the promising performance of fluid antenna in single and multiuser environments

    Post-stress interface trap generation induced by oxide-field stress with FN injection

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    Interface trap generation in nMOS transistors during both stressing and post-stress periods under the conditions of oxide field (dynamic and dc) stress with FN injection is investigated with charge pumping technique. In contrast to the post-stress interface trap generation induced by hot carrier stress which is a logarithmical function of post-stress time, the poststress interface trap generation induced by oxide-field stress with FN injection first increases with post-stress time but then becomes saturated. The mechanisms for the interface trap generation in both stressing and post-stress periods are described. © 1998 IEEE.published_or_final_versio

    Acceptors in undoped gallium antimonide

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    Undoped GaSb materials were studied by temperature dependent Hall (TDH) measurements and photoluminescence (PL). The TDH data reveals four acceptor levels (having ionization energies of 7meV, 32meV, 89meV and 123meV) in the as-grown undoped GaSb samples. The 32meV and the 89meV levels were attributed to the GaSb defect and the VGa-related defect. The Ga Sb defect was found to be the important acceptor responsible for the p-type nature of the present undoped GaSb samples because of its abundance and its low ionization energy. This defect was thermally stable after the 500°C annealing. Similar to the non-irradiated samples, the 777meV and the 800meV PL signals were also observed in the electron irradiated undoped GaSb samples. The decrease of the two peaks' intensities with respect to the electron irradiation dosage reveals the introduction of a non-radiative defect during the electron irradiation process, which competes with the transition responsible for the 777meV and the 800meV PL peaks.published_or_final_versio

    Performance of Machine Learning Aided Fluid Antenna System with Improved Spatial Correlation Model

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    Fluid antenna has emerged as a new antenna technology that enables software-controllable position reconfigurability for great diversity and multiplexing benefits. The performance of fluid antenna systems has recently been studied for single and multiuser environments adopting a generalized spatial correlation model that accounts for the channel correlation between the ports of the fluid antenna. The recent work [1] further devised machine learning algorithms to select the best port of fluid antenna in a more practical setting in which only a small number of ports is observable in the selection process, and found that extraordinary outage probability performance can be obtained. However, there is a concern of how the spatial correlation parameters are set to reflect the actual correlation structure for accurately evaluating the system performance. In this paper, the method in [2] is used to set the correlation parameter so that the model can accurately characterize the correlation amongst the ports of a fluid antenna in a given space. This paper revisits the port selection problem for single-user fluid antenna system where learning-based algorithms are employed to select the best port when only a small subset of the channel ports are known. The new results demonstrate that the impact of spatial correlation on the performance becomes more pronounced but the machine learning aided fluid antenna system is still able to match the performance of maximum ratio combining (MRC) system with many uncorrelated antennas
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