285 research outputs found

    Analytical Studies on a Modified Nagel-Schreckenberg Model with the Fukui-Ishibashi Acceleration Rule

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    We propose and study a one-dimensional traffic flow cellular automaton model of high-speed vehicles with the Fukui-Ishibashi-type (FI) acceleration rule for all cars, and the Nagel-Schreckenberg-type (NS) stochastic delay mechanism. By using the car-oriented mean field theory, we obtain analytically the fundamental diagrams of the average speed and vehicle flux depending on the vehicle density and stochastic delay probability. Our theoretical results, which may contribute to the exact analytical theory of the NS model, are in excellent agreement with numerical simulations.Comment: 3 pages previous; now 4 pages 2 eps figure

    Wi-Fi Sniffer Based Commuters Statistics Collection System For Reliable Bus Scheduling System

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    Traffic congestion issues have always been a concern for the fast growing metropolitans in which more than 90 percent of trips are made entirely by private means of transportation i.e. by car and motorcycle. As the country is actively engaged in infrastructure development especially in the transportation network to facilitate the movements of people and goods, a high demand for better public transportation is needed to reduce the issue of road congestion (percentage of GDI lost due to man hour lost in the traffic). Therefore, a cost effective Wi-Fi sniffing based bus commuters’ statistic collection system is designed and developed to study the feasibility of predicting the necessity of scheduling additional bus services when the detected number of Wi-Fi enabled devices exceeded the bus capacity. The developed system is subsequently deployed to the busiest university bus stop and the obtained result shows that variation of sniffed MAC address exhibit parallelism to the actual number of commuters waiting at the bus station as observed in the captured bus station video images. Result also shows that the MAC address based counting system can help to alert the bus management for better scheduling when the commuter at the particular bus stop is traveling to the same destination

    The Vertical Distribution of Ice-Nucleating Particles over the North China Plain: A Case of Cold Front Passage

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    Ice-nucleating particles (INPs) are crucial for cloud freezing processes in the atmosphere. Given the limited knowledge about the vertical distribution of INPs and its relation to aerosols in China, we present two aircraft observations of INPs over the North China Plain on 23 October 2019 and 25 October 2019, before and after a cold front passage. We used a well-established method to identify the INPs on a silicon wafer and then performed single-particle chemical composition analysis using an environmental scanning electron microscope-energy dispersive spectrometer (ESEM-EDS). The INP concentrations range from 0.1 to 9.2 L1^{−1} within activation temperatures from −20 to −29 °C. INPs are mostly concentrated within the boundary layer, and their concentration shows a decreasing trend with height (0.5~6 km) before the cold front passage. However, the highest INP concentration always appears at higher altitudes (4~5 km) after the cold front passage. The cold front passage also significantly weakens the correlations between the concentrations of INPs and aerosol particles at different sizes. The activated fraction (AF) of total aerosols increases from 106^{−6} to 104^{−4} with height from near ground to 6 km, reflecting a better nucleating capacity of the aerosols at higher altitudes. There is no obvious variation in AF after the cold front passage. Chemical analysis reveals that the INPs containing mineral dust components comprise the majority of total INPs during both flights. The proportion of pure mineral dust declines from 52.2% to 43.5% after the cold front passage while the proportion of mixed mineral dust increases from 23.9% to 45.7%, suggesting that an increased probability of aging or coating of INPs is introduced by the cold front during their long-distance transport. In addition, 88% of INPs have a diameter larger than 1 μm. This indicates that larger aerosols (>1 μm) are the major contributors to INPs at high altitudes despite their relatively low abundance. Our results demonstrate a significant impact of transport events on the sources and vertical distribution of INPs in the atmosphere

    Efficient routing on scale-free networks based on local information

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    In this letter, we propose a new routing strategy with a single free parameter α\alpha only based on local information of network topology. In order to maximize the packets handling capacity of underlying structure that can be measured by the critical point of continuous phase transition from free flow to congestion, the optimal value of α\alpha is sought out. By investigating the distributions of queue length on each node in free state, we give an explanation why the delivering capacity of the network can be enhanced by choosing the optimal α\alpha. Furthermore, dynamic properties right after the critical point are also studied. Interestingly, it is found that although the system enters the congestion state, it still possesses partial delivering capability which do not depend on α\alpha. This phenomenon suggests that the capacity of the network can be enhanced by increasing the forwarding ability of small important nodes which bear severe congestion.Comment: 4 pages, 7 figure

    Reverse micellar system in protein recovery - a review of the latest developments

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    Reversed micellar system (RMS) is an innovative technique used for the isolation, extraction and purification of proteins and enzymes. Studies have demonstrated that RMS is an efficient purification technology for extracting proteins and enzymes from natural plant materials or fermentation broth. Lately, reverse micelles have wider biological applications and the ease of scaling up and the possibility for the continuous process have made RMS a vital purification technique in various fields. In this study, an extensive review of RMS with the current application in biotechnology is examined. This review provides insights into the fundamental principles, key variables and parameters of RMS. In addition, a comparative study of RMS with other liquid-liquid extraction techniques is also included. The present review aims to provide a general overview of RMS by summarising the research works, since the introduction of the technology to current development

    A systematic review and meta-analysis comparing the efficacy and safety of ciprofol (HSK3486) versus propofol for anesthetic induction and non-ICU sedation

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    Background: Ciprofol (HSK3486) is a novel intravenous anesthetic agent that bears structural similarity to propofol and displays favorable pharmacodynamic characteristics such as rapid onset and offset. The meta-analysis aimed at comparing the efficacy and safety of ciprofol versus propofol in clinical practice.Methods: Medline, EMBASE, Google Scholar, Cochrane Library were searched from inception to April 2023. The primary outcome was success rate of sedation/anesthetic induction and differences in sedation/induction time. The secondary outcomes included risks of hemodynamic instability, respiratory complications, and pain on injection, as well as recovery profiles, satisfaction score, and top-up dose requirement.Results: Twelve RCTs (sedation: n = 6, anesthetic induction, n = 6, all conducted in China) involving 1,793 patients (age: 34–58 years) published from 2021 to 2023 were analyzed. Pooled results revealed no differences in success rate [risk ratio (RR) = 1, 95% confidence interval (CI): 0.99 to 1.01, I2 = 0%, 1,106 patients, p = 1] and time required for successful anesthetic induction/sedation [mean difference (MD) = 7.95 s, 95% CI: −1.09 to 16.99, I2 = 97%, 1,594 patients, p = 0.08]. The risks of top-up dose requirement (RR = 0.94, p = 0.48), cardiopulmonary complications [i.e., bradycardia (RR = 0.94, p = 0.67), tachycardia (RR = 0.83, p = 0.68), hypertension (RR = 1.28, p = 0.2), hypoxemia/pulmonary depression (RR = 0.78, p = 0.24)], and postoperative nausea/vomiting (RR = 0.85, p = 0.72), as well as discharge time (MD = 1.39 min, p = 0.14) and satisfaction score (standardized MD = 0.23, p = 0.16) did not differ significantly between the two groups. However, the ciprofol group had lower risks of hypotension (RR = 0.85, p = 0.02) and pain on injection (RR = 0.17, p < 0.00001) than the propofol group. The time to full alertness was statistically shorter in the propofol group (i.e., 0.66 min), but without clinical significance.Conclusion: Our results demonstrated similar efficacy between ciprofol and propofol for sedation and anesthetic induction, while ciprofol was associated with lower risks of hypotension and pain on injection. Future studies are warranted to evaluate the efficacy and safety of ciprofol in pediatric or the elderly populations.Systematic Review Registration: (https://www.crd.york.ac.uk/prospero/), identifier (CRD42023421278)
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