The Internet of things (IoT) can be used in our daily life. Home area network (HAN) is one of the applications of loT. However, deploying HAN for underdeveloped countries in Africa is not easy due to the lack of Inter...The Internet of things (IoT) can be used in our daily life. Home area network (HAN) is one of the applications of loT. However, deploying HAN for underdeveloped countries in Africa is not easy due to the lack of Internet connectivity and stable electricity. First of all, Internet in Africa is growing fast but the majority of countries in Africa have Internet penetration of less than 10%. Furthermore, the problem of accessing electricity varies greatly across African countries, which is still less than 30% of the average usage rate. The aim of this paper is to model a secure HAN based on IoT for resource constraints environment, which are focused on both network connectivity and energy stability. Poor connectivity, the prevalence of low-end devices and several other obstacles should be considered for the secure HAN deployment in developing and underdeveloped countries. The proposed HAN model will provide the resource constraints module composed of network connectivity function and energy stability function to support the two constraints based on the IoT basic module and the security and privacy module. The proposed HAN model could be securely applied to various countries HAN applications with poor electricity supply and network connectivity.展开更多
Non-interleaved chiral metasurfaces for high-spatial-resolution polarimetry are proposed and demonstrated.Furthermore,a convolutional neural network is incorporated to analyze interferometric images with the polarizat...Non-interleaved chiral metasurfaces for high-spatial-resolution polarimetry are proposed and demonstrated.Furthermore,a convolutional neural network is incorporated to analyze interferometric images with the polarization state of light,and it results in accurate Stokes parameters.展开更多
Individuals who are unable to walk independently spend most of the day in a wheelchair.This population is at high risk for developing pressure injuries caused by sitting.However,early diagnosis and prevention of these...Individuals who are unable to walk independently spend most of the day in a wheelchair.This population is at high risk for developing pressure injuries caused by sitting.However,early diagnosis and prevention of these injuries still remain challenging.Herein,we introduce battery-free,wireless,multimodal sensors and a movable system for continuous measurement of pressure,temperature,and hydration at skin interfaces.The device design includes a crack-activated pressure sensor with nanoscale encapsulations for enhanced sensitivity,a temperature sensor for measuring skin temperature,and a galvanic skin response sensor for measuring skin hydration levels.The movable system enables power harvesting,and data communication to multiple wireless devices mounted at skin-cushion interfaces of wheelchair users over full body coverage.Experimental evaluations and numerical simulations of the devices,together with clinical trials for wheelchair patients,demonstrate the feasibility and stability of the sensor system for preventing pressure injuries caused by sitting.展开更多
Using meta-imagers composed of a meta-lens and a complex-amplitude meta-modulator,all-optical convolutional processing that arbitrarily reshapes the point spread function of an optical system can now be implemented.
文摘The Internet of things (IoT) can be used in our daily life. Home area network (HAN) is one of the applications of loT. However, deploying HAN for underdeveloped countries in Africa is not easy due to the lack of Internet connectivity and stable electricity. First of all, Internet in Africa is growing fast but the majority of countries in Africa have Internet penetration of less than 10%. Furthermore, the problem of accessing electricity varies greatly across African countries, which is still less than 30% of the average usage rate. The aim of this paper is to model a secure HAN based on IoT for resource constraints environment, which are focused on both network connectivity and energy stability. Poor connectivity, the prevalence of low-end devices and several other obstacles should be considered for the secure HAN deployment in developing and underdeveloped countries. The proposed HAN model will provide the resource constraints module composed of network connectivity function and energy stability function to support the two constraints based on the IoT basic module and the security and privacy module. The proposed HAN model could be securely applied to various countries HAN applications with poor electricity supply and network connectivity.
文摘Non-interleaved chiral metasurfaces for high-spatial-resolution polarimetry are proposed and demonstrated.Furthermore,a convolutional neural network is incorporated to analyze interferometric images with the polarization state of light,and it results in accurate Stokes parameters.
基金supported by the Technology Innovation Program(00144157,Development of Heterogeneous Multi-Sensor Micro-System Platform)funded By the Ministry of Trade,Industry&Energy(MOTIE,korea)and the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(no.2021R1A2C3008742)supported by the MSIT(Ministry of Science and ICT),Korea,under the Grand Information Technology Research Center support program(IITP-2022-2016-0-00318)supervised by the IITP(Institute for Information&communications Technology Planning&Evaluation)Z.X.acknowledges the support from the National Natural Science Foundation of China(Grant No.12072057).
文摘Individuals who are unable to walk independently spend most of the day in a wheelchair.This population is at high risk for developing pressure injuries caused by sitting.However,early diagnosis and prevention of these injuries still remain challenging.Herein,we introduce battery-free,wireless,multimodal sensors and a movable system for continuous measurement of pressure,temperature,and hydration at skin interfaces.The device design includes a crack-activated pressure sensor with nanoscale encapsulations for enhanced sensitivity,a temperature sensor for measuring skin temperature,and a galvanic skin response sensor for measuring skin hydration levels.The movable system enables power harvesting,and data communication to multiple wireless devices mounted at skin-cushion interfaces of wheelchair users over full body coverage.Experimental evaluations and numerical simulations of the devices,together with clinical trials for wheelchair patients,demonstrate the feasibility and stability of the sensor system for preventing pressure injuries caused by sitting.
文摘Using meta-imagers composed of a meta-lens and a complex-amplitude meta-modulator,all-optical convolutional processing that arbitrarily reshapes the point spread function of an optical system can now be implemented.
