The energy transition towards increased electric power production from renewable energy (RE) resources creates new challenges to ensure the stability of power grids. In conventional power grids voltage fluctuations can be controlled locally. Here, it is explored whether this may be changed by the energy transition. It is well established that the increase of RE resources in power grids increases the amplitude of frequency deviations and the velocity with which these deviations spread throughout the power grid. However, its effect on voltage dynamics and propagation has not been systematically studied. Here, a systematic study is carried out of the transients of voltage amplitude, phase and frequency deviations due to local contingencies in dependence on system inertia, heterogeneity and topology. The 3rd order dynamic power grid model is studied numerically and analytically and compared with real grid simulations for the Nigerian (330 kV) power grid and other grid models, using DigSILENT PowerFactory software. A quantitative analysis of the parametric dependence of the velocity with which a disturbance propagates throughout the grid and of the period of oscillations of the frequency and voltage transients is provided. Beating patterns are found in the transients and are identified as footprints of the location of the fault bus, as caused by multiple reflections of propagating disturbances from the grid boundary. These may result in interarea oscillations. It is confirmed that voltage deviations remain local for realistic ranges of parameters, but that it can propagate by literally surfing on the frequency deviation wave. However, it is found that this no longer holds true when the electrical power in the grid approaches its critical value beyond which no stationary solution exists. Furthermore, time dependent second moments of the geodesic distance weighted with frequency deviations $S_{\delta \omega }(t)$ and voltage deviations $S_{\delta V}(t)$ , respectively are evaluated, confirming a ballistic disturbance propagation in homogeneous model grids. However, in real grid simulations, a linear time dependence of $S(t)$ is observed, indicating a diffusive propagation due to multiple scattering from the inhomogeneities in these power grids.
Background: Medical decision making represent a branch of medical informatics. Our decisions and actions are based not only on relevant information but also on our knowledge of the nature of problem that is being solved. Objective: The aim of this study was to describe and explaine the importance of medical decision making in physician's practice with information technology support. Methods: This is cross-sectional study based on reviewing of apropriate scientific literaure stored in scientific databases like PubMed, PubMed Central, Scopus, Embase, Hinary, etc, Results and Discussion: The reality is that the physician very often makes the decisions on the basis of the incomplete information. Besides that, the value of the available information for the processes of decision making is always relative regarding to the basis on the base of knowledge of the decision carrier. Medical decision making certainly be continuously exposed to it, which is the reason why it could not be of more important. The intricate aspects of medical decision making has been discussed in this article. A decision is a choice varying between several different courses of action that may be pursued. Each decision comes as a result of complex processes which provide two or more options providing results, as well as intro and retrospection, and examination or perspective into the future. As is in everyday life, the principles of decision making are present in medicine as well. Conclusion: Medical decision-making is a process of continuous balancing of concrete risks in which doctors show "loss aversion". Medical decisions are vital - to medical professionals, patients and society. They are difficult, and may provide positive outcomes, or poor complications. They test doctors maximally, and provide insight into the effectiveness of doctors. Doctors do not enter into a “business but social contract” with the patient. Additionally, it may ease and expedite the process of medical decision making, a luxury which was not always present for physicians.
Background: Everyday, doctors and individuals in the field of healthcare must make calculated decisions which have important consequences, impacting patients on the individual level, and communities and nations on a more global level. Healthcare professionals must at times make these choices with limited information, resources, and knowledge, and yet is is expected that these decisions are highly calculated and accurate. Objective: The aim of this study was to describe and explaine the importance of medical decision making in physician's practice. Methods: It is cross-sectional study based on reviewing of apropriate scientific literaure stored in scientific databases like PubMed Central Scopus, Embase, Hinary, etc, Results and Discussion: Medical decision making certainly be continuously exposed to it, which is the reason why it could not be of more important. The intricate aspects of medical decision making has been discussed in this article. A decision is a choice varying between several different courses of action that may be pursued. Each decision comes as a result of complex processes which provide two or more options providing results, as well as intro and retrospection, and examination or perspective into the future. As is in everyday life, the principles of decision making are present in medicine as well. In the world of biomedicine, decisions may rely on the available systems of information provided to the decision maker through medical documentation. Additionally, it may ease and expedite the process of medical decision making, a luxury which was not always present for physicians. Conclusion: Medical decision making is highly important to doctors and patients alike, as well as the broader population. Medical decisions are vital - to medical professionals, patients and society. They are difficult, and may provide positive outcomes, or poor complications. They test doctors maximally, and provide insight into the effectiveness of doctors. And finally, from the presented strategy, we can conclude that the mathematical models provides support in diagnosis and therapeutic selection in patients with heart damage by cardiovascular diseases and its helped to pysician, as decision maker, to decide which and when appropriate decision will be used. In health care, shared decision-making is increasingly embraced and recommended. It is important to involve patients in health care decisions, to communicate with them, and to provide patient-centered care, however formal models and evaluations in cardiovascular care are still in their infancy.
Although there is clear dose-dependence of pulmonary toxicity caused by inhalation of normobaric oxygen in animal studies, the threshold of toxicity in humans remains largely unknown. The aim of this systematic review of published clinical studies was to establish threshold in terms of total oxygen dose administered under normal pressure by inhalation that causes first clinical signs of toxicity. MEDLINE, EBSCO, The Cochrane Central Register of Controlled Trials (Central), SCIndeks, Scopus, Google Scholar, and ClinicalTrials.gov were searched from their foundation to April 2022. The systematic review was performed according to the pre-registered protocol at PROSPERO. The studies were included if describing toxic effects of normobaric oxygen therapy in humans. In total 11 human studies of poor quality were found, with either experimental or observational design. In none of the analyzed studies did oxygen therapy cause toxic effects on the respiratory tract if the concentration of oxygen in the inhaled air was below 50%, regardless of the rate of administration. The toxic consequences of inhaling oxygen at a concentration of more than 50% occurred only after oxygen was administered for more than 6 hours, at a rate of more than 7 L/min, and were mainly reflected in inflammation of the tracheobronchial mucosa, with epithelial erosions. Normobaric oxygen therapy can have toxic effects in humans if the oxygen concentration in the inhaled air is higher than 50%, if the administration rate is above 7 L/min, and if the application lasts at least 6 hours.
We present a resistance switching device that exhibits analogue potentiation and depression of conductance under the same voltage polarity. This contrasts with previously studied devices that potentiate and depress under opposite polarities. We refer to this mode of operation as the subthreshold regime due to it occurring at voltage or current biases that are insufficient to produce discrete or non-volatile switching. This behaviour has the potential to reduce the complexity of neuronal and synaptic circuitry in neuromorphic computing by removing the need for voltage pulses of both positive and negative polarities. The characteristically long timescales may also help replicate bio-realistic timings. In this article, we detail how to induce this unique behaviour, how to tune its properties to a desired response, and finally, we demonstrate one potential application.
Owing to the increasing engagement of service robots in everyday life, significant requirements are imposed on their control systems to ensure safe interaction between robots and humans. The stiffness of the motion executed by the service robots is not high, as with industrial robots, but has to be variable depending on the defined task. Therefore, a service robot needs to have soft actuation, delivering “human-like” motion dependant on the interaction force between the robot and its environment. Such an operation requires switching from the trajectory tracking (position control) mode to the interaction (force control) mode, and vice versa. Conventional control methods, based on hybrid position/force control, or switching between a position and force controller, may fail short in these cases. Thus, we have previously proposed a new control method, denoted as universal motion controller, that merges the position and force control into a single control structure. The control method is elaborated in this article, and its experimental validation is presented for the first time for multi-degree-of-freedom systems.
Intimacy is one of the fundamental aspects of our social life. It relates to intimate interactions with others, often including verbal self-disclosure. In this paper, we researched machine learning algorithms for quantification of the intimacy in the tweets. A new multilingual textual intimacy dataset named MINT was used. It contains tweets in 10 languages, including English, Spanish, French, Portuguese, Italian, and Chinese in both training and test datasets, and Dutch, Korean, Hindi, and Arabic in test data only. In the first experiment, linear regression models combine with the features and word embedding, and XLM-T deep learning model were compared. In the second experiment, cross-lingual learning between languanges was tested. In the third experiments, data was clustered using K-means. The results indicate that XLM-T pre-trained embedding might be a good choice for an unsupervised learning algorithm for intimacy detection.
In this paper we present VITAL-5G platform, a flexible 5G innovative infrastructure that can host Network Applications (NetApps) to optimize the performance and the efficiency of services in the Transport & Logistics (T&L) sector. It is a complete system that comprises hardware, software
From the pure health crisis that countries faced at the very beginning of the COVID-19 pandemic, in later stages it led to the creation of multiple economic and financial vulnerabilities. When the world economies started recovering from the pandemic negative impacts, Russia started its invasion of Ukraine. The study aims to add to the growing body of literature on the topic of crises caused by the COVID-19 and Russian–Ukraine war by analyzing and comparing the volatility of the world’s leading stock market performance benchmarks in the pre-crisis and crisis periods. For the analysis, Levene’s test is used to check the homogeneity/heterogeneity of variances of stock market returns. Analysis shows that all indexes performed better in the Russian–Ukraine crisis compared to the COVID-19 crisis, i.e., the volatility of returns of all indexes is significantly lower in the Russian-Ukraine crisis compared to the COVID-19 crisis.
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