为了扩展高频水声换能器带宽,添加背衬是方法之一,然而针对水声换能器的激励信号形式和工作状态,当前缺少针对水声换能器背衬设计的准则,本文开展了水声换能器背衬参数的作用机制研究工作。基于KLM (krimholtz leedom and matthaei)传...为了扩展高频水声换能器带宽,添加背衬是方法之一,然而针对水声换能器的激励信号形式和工作状态,当前缺少针对水声换能器背衬设计的准则,本文开展了水声换能器背衬参数的作用机制研究工作。基于KLM (krimholtz leedom and matthaei)传输线模型研究了背衬厚度、衰减系数及特征阻抗对水声换能器性能的影响。研究结果表明:背衬在水声换能器中作为谐振体的一部分参与振动并形成了若干阶纵向振动模态,其作用是增加系统阻尼,而不是吸收声波。从扩展带宽的角度出发,背衬的衰减系数应尽量大,此时,发送电压响应波动减弱且对响应幅值影响很小;背衬特征阻抗能够调节两响应峰的相对幅值,阻抗过高或者过低都不利于宽带的形成,因此选择中等特征阻抗的背衬较为适宜。最后,基于上述的背衬优化方法,制备了水声换能器样机,其测试带宽为102%,与理论吻合较好。展开更多
In this paper,we propose an authentication method that use mouse and keystroke dynamics to enhance online privacy and security.The proposed method identifies personalized repeated user interface(UI)sequences by analyzi...In this paper,we propose an authentication method that use mouse and keystroke dynamics to enhance online privacy and security.The proposed method identifies personalized repeated user interface(UI)sequences by analyzing mouse and keyboard data.To this end,an Apriori algorithm based on the keystroke-level model(KLM)of the human–computer interface domain was used.The proposed system can detect repeated UI sequences based on KLM for authentication in the software.The effectiveness of the proposed method is verified through access test-ing using commercial applications that require intensive UI interactions.The results show using our cognitive mouse-and-keystroke dynamics system can com-plement authentication at the application level.展开更多
文摘为了扩展高频水声换能器带宽,添加背衬是方法之一,然而针对水声换能器的激励信号形式和工作状态,当前缺少针对水声换能器背衬设计的准则,本文开展了水声换能器背衬参数的作用机制研究工作。基于KLM (krimholtz leedom and matthaei)传输线模型研究了背衬厚度、衰减系数及特征阻抗对水声换能器性能的影响。研究结果表明:背衬在水声换能器中作为谐振体的一部分参与振动并形成了若干阶纵向振动模态,其作用是增加系统阻尼,而不是吸收声波。从扩展带宽的角度出发,背衬的衰减系数应尽量大,此时,发送电压响应波动减弱且对响应幅值影响很小;背衬特征阻抗能够调节两响应峰的相对幅值,阻抗过高或者过低都不利于宽带的形成,因此选择中等特征阻抗的背衬较为适宜。最后,基于上述的背衬优化方法,制备了水声换能器样机,其测试带宽为102%,与理论吻合较好。
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF),funded by the Ministry of Education(2021R1I1A3058103,2019R1A2C1002525).
文摘In this paper,we propose an authentication method that use mouse and keystroke dynamics to enhance online privacy and security.The proposed method identifies personalized repeated user interface(UI)sequences by analyzing mouse and keyboard data.To this end,an Apriori algorithm based on the keystroke-level model(KLM)of the human–computer interface domain was used.The proposed system can detect repeated UI sequences based on KLM for authentication in the software.The effectiveness of the proposed method is verified through access test-ing using commercial applications that require intensive UI interactions.The results show using our cognitive mouse-and-keystroke dynamics system can com-plement authentication at the application level.
