Search

近年来，数字金融蓬勃发展，金融科技日趋成熟，信息技术的发展对社会产生巨大积极作用的同时也带来了新型风险，网络黑产呈爆发式增长，电信网络诈骗给人民群众造成了巨大的财产损失。在数字金融时代，商业银行既迎来了新的机遇与动力，又面临着新的挑战和数字化变革的要求，线上金融业务已经成为新的主战场。在此背景下，基于 RFM 高维衍生特征和对机器学习算法的研究，构建了基于高维交易行为画像的事中反欺诈机器学习模型。依托大数据、流计算等技术，通过在系统化部署、应用策略以及模型迭代优化等环节的实践，形成了一套基于机器学习模型的事中风控方案。实践证实，该模型的AUC达到了0.972，可以敏锐洞察欺诈风险，实现毫秒级的欺诈交易识别，对于提升线上数字金融业务的事中风控能力具有一定的推广价值和借鉴意义。

Objectives: The Turkey-Syria earthquake occurred on February 6th, 2023, and caused heavy casualties and property losses. This paper used high-resolution night-time light images to assess the damage of the affected cities. Methods: A multivariate power function regression model was used for intercalibration between sustainable development goals satellite-1(SDGSAT-1) and Yangwang-1 night-time light images. And the disaster assessment was carried out in the cities of Adiyaman and Antakya-Defne in Turkey. Results: The results show that the power facilities of Adiyaman and Antakya-Defne were severely damaged in the earthquake. The light loss rate of more than half of the building area exceeded 80%, and the overall light loss rate of the building area exceeded 70%. Additionally, the light loss rate in the east of Adiyaman was higher than that in the west, and the light loss rate in the downtown area of Antakya-Defne was higher than that in the suburbs. Conclusions: The high-resolution night-time light images can effectively assess the impact caused by natural disasters, and the assessment results can also help local government departments guide emergency relief and reconstruction work after the earthquake. [ABSTRACT FROM AUTHOR]

Copyright of Geomatics & Information Science of Wuhan University is the property of Geomatics & Information Science of Wuhan University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shandong Medical Journal is the property of Shandong Medical Health Newspapers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Progress in Modern Biomedicine is the property of Publishing House of Progress in Modern Biomedicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Modern Medicine & Health is the property of Journal of Modern Medicine & Health and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A series of gas flow tests using He and CO2 are conducted on shale samples in triaxial flow equipment for rock to investigate the influencing mechanisms of pore pressure and temperature on permeability. The experimental results show that non-sorbing He permeability increases with pore pressure. However, the permeability evolution of sorbing CO2 first decreases and then recovers as pore pressure increases. Then, a theoretical model is proposed to predict the permeability change induced by effective stress, matrix swelling and gas slippage. Furthermore, the validation of the proposed model is conducted by fitting the experimental results from this paper. The flow tests under variable temperatures demonstrate that the shale permeability declines first at low temperature, and then increases at high temperature. It is observed that temperature has a stronger impact on permeability under lower confining pressure. With the increase of temperature, the slippage effects on the permeability become stronger. The effect of temperature on gas permeability is altered as a combined action of the thermal expansion of grains, gas slippage, the thermal motion of gas molecular and the matrix swelling induced by adsorption. At last a theoretical model is built with the consideration of temperature effects, and is validated by comparing the experimental results and analytic results, which gives satisfactory agreements between each other. [ABSTRACT FROM AUTHOR]

Through the test of specific surface area, total pore volume and adsorption characteristic of soft and hard coal, it is found that for the same metamorphic degree, the specific surface area and total pore volume of soft coal is several times to that of hard coal, but the adsorption capacity of soft and hard coal is equivalent. In order to solve this problem, according to the thermodynamic principle and methane adsorption mechanism in coal, adsorption layer thickness theory in coal body pore was established to numerically calculate and analyzed adsorption layer thickness (adsorption layer number), which is effected by pore and adsorption equilibrium pressure. At the same time, pore size and pore volume distribution were measured by mercury injection test, and adsorption isotherms of methane in coal was calculated. The results show that based on the adsorption layer thickness theory, the methane adsorption layer thickness decreases with negative index relation to pore diameter at the same adsorption equilibrium pressure, which indicates that methane adsorption in coal has different molecular layer. The relation of pore size and its pore volume can be fitted by piecewise functions. Gas adsorption isotherms in different coal samples are calculated based on the layer thickness, and both the change trend and quantify are consistent with the measured results, the error is less than 6.5%. Therefore, the adsorption layer thickness theory reveals the methane adsorption characteristics of soft and hard coal. Thus, as long as the pore size distribution characteristics of coal is measured, adsorption quantify can be calculated by adsorption layer thickness theory, which provides a new method for the gas content prediction in coal seam. [ABSTRACT FROM AUTHOR]