9,103 research outputs found

    An Application of Lorentz Invariance Violation in Black Hole Thermodynamics

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    In this paper, we have applied the Lorentz-invariance-violation (LIV) class of dispersion relations (DR) with the dimensionless parameter n = 2 and the "sign of LIV" {\eta}_+ = 1, to phenomenologically study the effect of quantum gravity in the strong gravitational field. Specifically, we have studied the effect of the LIV-DR induced quantum gravity on the Schwarzschild black hole thermodynamics. The result shows that the effect of the LIV-DR induced quantum gravity speeds up the black hole evaporation, and its corresponding black hole entropy undergoes a leading logarithmic correction to the "reduced Bekenstein-Hawking entropy", and the ill defined situations (i.e. the singularity problem and the critical problem) are naturally bypassed when the LIV-DR effect is present. Also, to put our results in a proper perspective, we have compared with the earlier findings by another quantum gravity candidate, i.e. the generalized uncertainty principle (GUP). Finally, we conclude from the inert remnants at the final stage of the black hole evaporation that, the GUP as a candidate for describing quantum gravity can always do as well as the LIV-DR by adjusting the model-dependent parameters, but in the same model-dependent parameters the LIV-DR acts as a more suitable candidate.Comment: 18 pages, 7 figure

    What Motivates People to Donate in Medical Charitable Crowdfunding Projects? A Trust Theory Perspective

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    In recent years, the micro-public welfare model based on social network has been widely used in medical crowdfunding, providing a novel solution for patients facing financial difficulties. Using social networks to eliminate time and space constraints on offline donations, more potential donors can be found. Based on the trust theory, this paper collected the medical crowdfunding projects data of public welfare on Weibo from 2012 to 2018, combined with the number of followers, regions and identity information of the project promoters on Weibo social media, and explored the influencing factors of the amount of public crowdfunding projects by using multi-source data. In the fundraising process of medical crowdfunding projects, the subject of trust construction is the donors, and the object of trust includes not only the relevant information of the patient, but also the promoter and the information characteristics of the project. This paper aims to build a theoretical model of trust from promoters, patients, project information characteristics, so as to explore the factors influencing the fundraising ability of medical projects under the micro-public welfare model. The results show that promoters, patients and project information characteristics can affect the trust of donors, and thus affect the amount of money raised by medical crowdfunding projects. On the basis of the above empirical research, this paper also puts forward some suggestions for the healthy development of micro-public welfare based on the problems found

    Assessment of diagnostic value of age for meridional amblyopia with Logistic regression and receiver operating characteristic curve

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    AIM: To assess the diagnostic value of age for meridional amblyopia by Logistic regression and receiver operating characteristic(ROC)curve.<p>METHODS: A total of 1 005 children(1 910 eyes)with unknown ocular abnormalities other than with-the-rule astigmatism(aged 4-8 years)were recruited. Astigmatism >or =1.00D and sphere < or = 3.00D were present in one or both eyes. The difference of sphere between both eyes was less 1.50D. The difference of astigmatism between both eyes was less 1.00D. All astigmatism was calculated by the absolute value. By analyzing age, sex, astigmatism type, diopter of cylinder and diopter of sphere with Logistic regression, two mathematical models were established. Then the diagnostic efficacy of the model was assessed using the ROC curve.<p>RESULTS: The model 1 included 4 parameters(sex, astigmatism type, diopter of cylinder and diopter of sphere). The model 2 included 5 parameters(the 4 parameters of the model 1 adding age). Using Logistic regression, the diopter of cylinder had an influence on the diagnosis of meridional amblyopia in two models. In model 2, age was another influencing factor on the diagnosis of meridional amblyopia. The model 1 area under ROC curve(AUC)was 0.64, and the model 2 was 0.74. The area of model 2 was greater than the model 1. There was statistical difference in the AUC of two models(<i>P</i><0.05).<p>CONCLUSION: Age might be an influential factor on the diagnosis of meridional amblyopia using Logistic regression and ROC curve
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