777 research outputs found

    BIOMECHANICAL STUDY ON AIM TECHNIQUE IN CHINESE ELITE FREE PISTOL ATHLETES.

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    INTRODUCTION: The purpose of this study was to analyze the aim technique of elite Chinese free pistol athletes. Pistol shooting in competition requires the athlete to complete 60 shots, consecutively and accurately. This provides a challenge for the marksmen, to maintain the high level of strength needed to perform the technical movements and under pressure. This paper presents a biomechanical study of the shooting techniques using the SELSPOT system. It was used to measure movements of the body-links and firearms in the aiming period in elite Chinese male pistol shooters

    AI-assisted Protective Action: Study of ChatGPT as an Information Source for a Population Facing Climate Hazards

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    ChatGPT has been emerging as a novel information source, and it is likely that the public might seek information from ChatGPT while taking protective actions when facing climate hazards such as floods and hurricanes. The objective of this study is to evaluate the accuracy and completeness of responses generated by ChatGPT when individuals seek information about aspects of taking protective actions. The survey analysis results indicated that: (1) the emergency managers considered the responses provided by ChatGPT as accurate and complete to a great extent; (2) it was statistically verified in evaluations that the generated information was accurate, but lacked completeness, implying that the extent of information provided is accurate; and (3) information generated for prompts related to hazard insurance received the highest evaluation, whereas the information generated related to evacuation received the lowest. This last result implies that, for complex, context-specific protective actions (such as evacuation), the information was rated as less complete compared with other protective actions. Also, the results showed that the perception of respondents regarding the utility of AI- assistive technologies (such as ChatGPT) for emergency preparedness and response improved after taking the survey and evaluating the information generated by ChatGPT. The findings from this study provide empirical evaluation regarding the utility of AI-assistive technologies for improving public decision-making and protective actions in disasters

    Lower Bound on Translative Covering Density of Tetrahedra

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    In this paper, we present the first nontrivial lower bound on the translative covering density of tetrahedra. To this end, we show the lower bound, in any translative covering of tetrahedra, on the density relative to a given cube. The resulting lower bound on the translative covering density of tetrahedra is 1+1.227×10−31+1.227\times10^{-3}

    Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for polymer analysis: solvent effect in sample preparation

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    AbstractThe success of matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry for the characterization of polymer structures and for the determination of average molecular weights and distributions depends on the use of a proper sample/matrix preparation protocol. This work examines the effect of solvents, particularly solvent mixtures, used to prepare polymer, matrix, and cationization reagent solutions, on MALDI analysis. It is shown that the use of solvent mixtures consisting of polymer solvents does not have a significant effect on the molecular weight determination of polystyrene 7000 and poly(methyl methacrylate) 3750. However, solvent mixtures containing a polymer nonsolvent can affect the signal reproducibility and cause errors in average weight measurement. This solvent effect was further investigated by using confocal laser fluorescence microscopy in conjunction with the use of a fluorescein-labeled polystyrene. It is demonstrated that sample morphology and polymer distribution on the probe can be greatly influenced by the type of solvents used. For sample preparation in MALDI analysis of polymers, it is important to select a solvent system that will allow matrix crystallization to take place prior to polymer precipitation. The use of an excess amount of any polymer nonsolvent should be avoided

    Lead to Elevate the Temperature and Speed of Emergency Rescue and Nursing Care of Common Carotid Artery Rupture and Massive Hemorrhage after Operation of Typical Esophageal Cancer

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    Objective: Objective To explore the first aid and nursing of patientswith anastomotic fistula after radical resection of esophagus carcinomacomplicated with major carotid hemorrhage. Methods: The clinical dataof anastomotic fistula complicated with carotid artery rupture and massivehemorrhage after radical resection of typical esophageal carcinoma wereanalyzed and summarized. Results: Through the close cooperation ofmedical care, the rescue was successful. Conclusion: Earlier preventionobservation, raising first aid consciousness and actively cooperating withdoctors can improve the success rate of rescue

    Road Network Vulnerability Analysis Based on Improved Ant Colony Algorithm

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    We present an improved ant colony algorithm-based approach to assess the vulnerability of a road network and identify the critical infrastructures. This approach improves computational efficiency and allows for its applications in large-scale road networks. This research involves defining the vulnerability conception, modeling the traffic utility index and the vulnerability of the road network, and identifying the critical infrastructures of the road network. We apply the approach to a simple test road network and a real road network to verify the methodology. The results show that vulnerability is directly related to traffic demand and increases significantly when the demand approaches capacity. The proposed approach reduces the computational burden and may be applied in large-scale road network analysis. It can be used as a decision-supporting tool for identifying critical infrastructures in transportation planning and management
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