针对地质灾害易发性评价因子分级数不确定的问题,引入自适应膨胀因子模糊覆盖分级方法(fuzzy cover approach for clustering based on adaptive inflation factor,AIFFC)对易发性评价因子分级进行优化。以湖南省湘乡市为研究区,提取了...针对地质灾害易发性评价因子分级数不确定的问题,引入自适应膨胀因子模糊覆盖分级方法(fuzzy cover approach for clustering based on adaptive inflation factor,AIFFC)对易发性评价因子分级进行优化。以湖南省湘乡市为研究区,提取了坡度、坡向、高程、年平均降雨量、归一化植被指数、道路、断层、岩性和土地利用9类评价因子,运用AIFFC及自然断点法(natural breakpoint classification,NBC)对连续型因子进行分级,并分别代入加权信息量模型和随机森林模型,获取研究区易发性区划图。采用单因子分级结果精度、灾积比分析和易发性分区结果对AIFFC分级法的优越性进行检验,结果表明:各因子采用AIFFC算法分级的AUC值均高于自然断点法;基于AIFFC的随机森林模型及加权信息量模型的高易发区灾积比分别提升了56.3%、74.6%,低易发区灾积比分别降低了48%、58.1%,AUC值分别提升了7.6%、2.7%。采用AIFFC分级方法优化了地质灾害易发性评价因子分级,显著提高了地质灾害易发性评价的合理性。展开更多
现阶段我国节能减排的具体工作逐渐展开,机械设计中节能减排的研究方向主要围绕机械元件性能提升等方面开展。本文通过数字化平台实现无纸化高效设计,减少重复性开发,提升设计效率,达到减少碳排放的目标。动力头是旋挖钻机的核心部件,...现阶段我国节能减排的具体工作逐渐展开,机械设计中节能减排的研究方向主要围绕机械元件性能提升等方面开展。本文通过数字化平台实现无纸化高效设计,减少重复性开发,提升设计效率,达到减少碳排放的目标。动力头是旋挖钻机的核心部件,具有结构紧凑、噪声小和效率高的特点。针对动力头设计中计算复杂、效率低的问题,开发了旋挖钻机数字化设计平台系统,简化设计流程,缩短设计周期。系统基于Visual Studio 2019平台开发,采用MFC(Microsoft Foundation Classes)框架C++语言编写,将参数化设计、参数传递、参数化分析、工程图管理和数据库管理划分为不同的模块进行设计,实现了零部件参数化设计、有限元分析与工程图自动生成与管理功能的集成。通过调用APDL程序语言,将命令流整合进而构建了完整的有限元分析中的建模、分析、后处理的流程,将传统较为复杂的机械设计流程用程序编写的方式集成到平台,实现部分设计参数的平台自动选取。经验证,设计与测试结果一致,提高了数字化平台的自动化水平和设计效率,通过高效的设计流程实现节能减排的目标。展开更多
The anti-aging effects of a cream containing L-carnosine and ginseng root extract to provide a reference for the evaluation and development of anti-aging cosmetics were tested. Sixty healthy females, aged 35-60,were g...The anti-aging effects of a cream containing L-carnosine and ginseng root extract to provide a reference for the evaluation and development of anti-aging cosmetics were tested. Sixty healthy females, aged 35-60,were grouped into test sample and placebo groups. Skin elasticity, gloss, and wrinkles of the participants were analyzed before use and after use for 8 weeks. Instrument measurement results showed that after 8 weeks,skin elasticity, gloss, and wrinkles in the members of the test sample group obviously improved relative to those of the placebo group. Clinical effect assessment results showed that subjects did not experience adverse skin reactions, and their skin gloss showed obvious improvement. Self-assessment results showed that 87%subjects are satisfied with the test sample. Cream containing L-carnosine and ginseng root extract has a certain anti-aging effect.展开更多
In complex systems,functional dependency and physical dependency may have a coupling effect.In this paper,the reliability of a k-out-of-n system is analyzed considering load-sharing effect and failure mechanism(FM)pro...In complex systems,functional dependency and physical dependency may have a coupling effect.In this paper,the reliability of a k-out-of-n system is analyzed considering load-sharing effect and failure mechanism(FM)propagation.Three types of FMs are considered and an accumulative damage model is proposed to illustrate the system behavior of the k-out-of-n system and the coupling effect between load-sharing effect and FM propagation effect.A combinational algorithm based on Binary decision diagram(BDD)and Monte-Carlo simulation is presented to evaluate the complex system behavior and reliability of the k-out-of-n system.A current stabilizing system that consists of a 3-out-of-6 subsystem with FM propagation effect is presented as a case to illustrate the complex behavior and to verify the applicability of the proposed method.Due to the coupling effect change,the main mechanism and failure mode will be changed,and the system lifetime is shortened.Reasons are analyzed and results show that different sensitivity factors of three different FMs lead to the change of the development rate,thus changing the failure scenario.Neglecting the coupling effect may lead to an incomplete and ineffective measuring and monitoring plan.Design strategies must be adopted to make the FM propagation insensitive to load-sharing effect.展开更多
文摘针对地质灾害易发性评价因子分级数不确定的问题,引入自适应膨胀因子模糊覆盖分级方法(fuzzy cover approach for clustering based on adaptive inflation factor,AIFFC)对易发性评价因子分级进行优化。以湖南省湘乡市为研究区,提取了坡度、坡向、高程、年平均降雨量、归一化植被指数、道路、断层、岩性和土地利用9类评价因子,运用AIFFC及自然断点法(natural breakpoint classification,NBC)对连续型因子进行分级,并分别代入加权信息量模型和随机森林模型,获取研究区易发性区划图。采用单因子分级结果精度、灾积比分析和易发性分区结果对AIFFC分级法的优越性进行检验,结果表明:各因子采用AIFFC算法分级的AUC值均高于自然断点法;基于AIFFC的随机森林模型及加权信息量模型的高易发区灾积比分别提升了56.3%、74.6%,低易发区灾积比分别降低了48%、58.1%,AUC值分别提升了7.6%、2.7%。采用AIFFC分级方法优化了地质灾害易发性评价因子分级,显著提高了地质灾害易发性评价的合理性。
文摘现阶段我国节能减排的具体工作逐渐展开,机械设计中节能减排的研究方向主要围绕机械元件性能提升等方面开展。本文通过数字化平台实现无纸化高效设计,减少重复性开发,提升设计效率,达到减少碳排放的目标。动力头是旋挖钻机的核心部件,具有结构紧凑、噪声小和效率高的特点。针对动力头设计中计算复杂、效率低的问题,开发了旋挖钻机数字化设计平台系统,简化设计流程,缩短设计周期。系统基于Visual Studio 2019平台开发,采用MFC(Microsoft Foundation Classes)框架C++语言编写,将参数化设计、参数传递、参数化分析、工程图管理和数据库管理划分为不同的模块进行设计,实现了零部件参数化设计、有限元分析与工程图自动生成与管理功能的集成。通过调用APDL程序语言,将命令流整合进而构建了完整的有限元分析中的建模、分析、后处理的流程,将传统较为复杂的机械设计流程用程序编写的方式集成到平台,实现部分设计参数的平台自动选取。经验证,设计与测试结果一致,提高了数字化平台的自动化水平和设计效率,通过高效的设计流程实现节能减排的目标。
文摘The anti-aging effects of a cream containing L-carnosine and ginseng root extract to provide a reference for the evaluation and development of anti-aging cosmetics were tested. Sixty healthy females, aged 35-60,were grouped into test sample and placebo groups. Skin elasticity, gloss, and wrinkles of the participants were analyzed before use and after use for 8 weeks. Instrument measurement results showed that after 8 weeks,skin elasticity, gloss, and wrinkles in the members of the test sample group obviously improved relative to those of the placebo group. Clinical effect assessment results showed that subjects did not experience adverse skin reactions, and their skin gloss showed obvious improvement. Self-assessment results showed that 87%subjects are satisfied with the test sample. Cream containing L-carnosine and ginseng root extract has a certain anti-aging effect.
基金This work was supported by the National Natural Science Foundation of China(61503014).
文摘In complex systems,functional dependency and physical dependency may have a coupling effect.In this paper,the reliability of a k-out-of-n system is analyzed considering load-sharing effect and failure mechanism(FM)propagation.Three types of FMs are considered and an accumulative damage model is proposed to illustrate the system behavior of the k-out-of-n system and the coupling effect between load-sharing effect and FM propagation effect.A combinational algorithm based on Binary decision diagram(BDD)and Monte-Carlo simulation is presented to evaluate the complex system behavior and reliability of the k-out-of-n system.A current stabilizing system that consists of a 3-out-of-6 subsystem with FM propagation effect is presented as a case to illustrate the complex behavior and to verify the applicability of the proposed method.Due to the coupling effect change,the main mechanism and failure mode will be changed,and the system lifetime is shortened.Reasons are analyzed and results show that different sensitivity factors of three different FMs lead to the change of the development rate,thus changing the failure scenario.Neglecting the coupling effect may lead to an incomplete and ineffective measuring and monitoring plan.Design strategies must be adopted to make the FM propagation insensitive to load-sharing effect.
