This study presents the development and characterization of a nanomechanical gas sensor array with piezoresistive detectors for a wide range of applications.The sensors,made of silicon and polymers and integrated with...This study presents the development and characterization of a nanomechanical gas sensor array with piezoresistive detectors for a wide range of applications.The sensors,made of silicon and polymers and integrated with the piezoresistive sensors on a silicon-on-insulator wafer,convert to electrical signals the stress caused by volume change of polymer induced by gas absorption.The fabrication of the sensors incorporates a process where Polymer A(Polyolefin),Polymer B(Fluorocarbon polymer)Polymer C(Acrylic resin),and Polymer D(Amino polymer),are deposited within silicon slits,demonstrating their distinct responses to various vapor species.These sensors show swift response times and efficient recovery periods,which makes them promising for real-time multiple gas and smell monitoring applications.An array of four nanomechanical sensors with polymers shows high repeatability and sensitivity when subjected to multiple gas exposure and turn-off cycles.The gas sensor arrays,effectively monitoring fish quality over several days,suggest a potential for determining optimal storage and early spoilage detection in perishables.The study demonstrates that the nanomechanical sensor array can accurately distinguish between different gas concentrations using principal component analysis,paving the way for real-time,automated multiple gas detection and analysis without human intervention.展开更多
This paper presents a new face detection approach to real-time applications, which is based on the skin color model and the morphological filtering. First the non-skin color pixels of the input image are removed based...This paper presents a new face detection approach to real-time applications, which is based on the skin color model and the morphological filtering. First the non-skin color pixels of the input image are removed based on the skin color model in the YC rC b chrominance space, from which we extract candidate human face regions. Then a mathematical morphological filter is used to remove noisy regions and fill the holes in the candidate skin color regions. We adopt the similarity between the human face features and the candidate face regions to locate the face regions in the original image. We have implemented the algorithm in our smart media system. The experiment results show that this system is effective in real-time applications.展开更多
A new type of intelligent recolser controller installed on the outdoor rod is developed, which is mainly composed of microcontroller of Intel 87C196KC 20 and CPLD devices. This controller integrates all the functions ...A new type of intelligent recolser controller installed on the outdoor rod is developed, which is mainly composed of microcontroller of Intel 87C196KC 20 and CPLD devices. This controller integrates all the functions of measuring, controlling, protection, fault diagnosis, communication, remote controlled operation and self power devices with infra red remote control devices as a unit. The controller applies the distributed structure, field concentration line and intelligent technology to seal up the synthetic servomechanisms such as the microcomputer based protection and measuring devices in the second stage of the mini out door transformer substation, which are distributed on the outdoor circuit switches on the spot and formed as a whole. Therefore, this technology can transform a large number of ordinary homemade SF 6 circuit beaker and vacuum circuit breaker into intelligent circuit recloser, thus replacing the expensive imported automatic circuit recolser.展开更多
Accurately identifying the location and type of internal defects in gas-insulated switchgear(GIS)is a challenge.To address this challenge,this study proposes a novel method for the nondestructive detection of GIS inte...Accurately identifying the location and type of internal defects in gas-insulated switchgear(GIS)is a challenge.To address this challenge,this study proposes a novel method for the nondestructive detection of GIS internal defects.This method is based on x-ray digital radiography(X-DR)technology and an improved real-time models for object detection(RTMdet)algorithm,namely GIS-specific localised internal defect-RTMdet.Firstly,the X-DR images of GIS are preprocessed by dynamic limit adaptive histogram equalisation algorithm to improve the images contrast.Then,a convolution shuffle upsample module for upsampling is proposed,which enlarges the defect feature map by multi-convolution and pixel shuffling,reduces the information loss,and enhances the interaction between the feature information.Finally,both the multi-channel attention net and the global attention mechanism are integrated into the neck network for enhancing local feature extraction and global information association.Experiments demonstrate that the pro-posed method achieves a mean average precision@0.5:0.95 of 94.9%,showcasing excellent overall performance and generalisation ability,and is more suitable for accurate nondestructive detection of internal defects of GIS in complex scenarios.展开更多
Mid-infrared(MIR)spectroscopy is instrumental in addressing gas molecule-related environmental and ecologi-cal challenges.Especially,massively parallel sensing capability is critical to multi-species molecules analysi...Mid-infrared(MIR)spectroscopy is instrumental in addressing gas molecule-related environmental and ecologi-cal challenges.Especially,massively parallel sensing capability is critical to multi-species molecules analysis,en-abling the demands for various MIR gas characterizations.However,real-time,high-accuracy parallel sensing for multiple gases remains a significant challenge due to the limitations in laser bandwidth and sampling speed.Here,we present a broadband MIR dual-comb spectrometer for the simultaneous detection of multiple greenhouse gases.This MIR spectrometer employs a scheme of difference frequency generation(DFG),directly producing a wide spectrum spanning 3.2–4.7μm with over 300,000 comb-tooth-resolved frequency lines at a 100 MHz resolution.In addition,we demonstrated the parallel detection of four mixed gas molecules(CH_(4),C_(2)H_(2),CO,and N_(2)O),in which the absorptions were in excellent agreement with HITRAN database.This broadband MIR dual-comb spectrometer is promising to be integrated with only fiber devices and periodically poled lithium niobate waveguides,providing a high-precision,high-efficiency approach for massively parallel sensing in atmos-pheric or industrial monitoring.展开更多
Background:Despite the high prevalence of strongyloidiasis in the Laotian population,Laotian hospitals still lack diagnostic capacity to appropriately diagnose Strongyloides stercoralis infections.This cross-sectional...Background:Despite the high prevalence of strongyloidiasis in the Laotian population,Laotian hospitals still lack diagnostic capacity to appropriately diagnose Strongyloides stercoralis infections.This cross-sectional hospital-based study was conducted to assess the prevalence of Strongyloides stercoralis infection among hospitalized patients treated at Mahosot Hospital,the primary reference hospital of Lao People’s Democratic Republic(Lao PDR),and to validate feasible methods for diagnosing S.stercoralis infection at hospital’s laboratory.Methods:Between September and December 2018,stool samples of 104 inpatients were investigated for S.stercoralis infection by wet smear,Baermann technique,Koga Agar plate culture(KAPC),and real-time detection polymerase chain reaction(RTD-PCR)at the Infectious Diseases Ward of the Mahosot Hospital in Vientiane.The sensitivity,the specificity,the negative predictive value(NPV)of each diagnostic test,as well as their combination(s)was calculated using a composite reference standard(CRS).The correlation of the different test methods was assessed by chi-square or Fisher’s exact test.Cohen’s kappa coefficient was used to assess the diagnostic agreement of the different test methods.Results:The overall prevalence of S.stercoralis infections among the study population was 33.4%.The cumulative infection prevalence statistically significantly increased from the lowest age group of 40 years and below(22.4%),to the medium(40.0%)and to the oldest age group of 61 year and above(72.7%)(P=0.003).The cumulative infection prevalence of CRS was considerably higher in male(40.4%)compared to female patients(28.1%),but not statistically different(P=0.184).The diagnostic sensitivity of Baermann technique,KAPC,RTD-PCR,and the combination of Baermann technique and KAPC were 60.0,60.0,74.3,and 77.1%,respectively.Only 13 patients(37.1%)of the total 35 S.stercoralis patients diagnosed with any technique had a simultaneously positive diagnostic test with Baermann,KAPC and RTD-PCR.Conclusions:We identified Baermann technique and KAPC to be currently the most feasible and implementable standard methods for diagnosing S.stercoralis at a hospital setting such as Mahosot Hospital and provincial and district hospitals in Lao PDR and other low-and middle income countries in Southeast Asia.Trial registration:This study was approved by the National Ethics Committee for Health Research in Lao PDR(reference no.083/NECHR)and by the Ethics Committee Northwest and Central Switzerland(reference no.2018–00594).展开更多
基金supported partly by Grant-in-Aid for Transformative Research Areas,Grant No.24H02231the Japan Agency for Medical Research and Development(AMED),Grant No.JP21zf0127001+1 种基金Cross-Ministerial Strategic Innovation Promotion Program(SIP),with funding provided by the New Energy and Industrial Technology Development Organization(NEDO)supported in part by the Micro/Nanomachining Education Center,Tohoku University.
文摘This study presents the development and characterization of a nanomechanical gas sensor array with piezoresistive detectors for a wide range of applications.The sensors,made of silicon and polymers and integrated with the piezoresistive sensors on a silicon-on-insulator wafer,convert to electrical signals the stress caused by volume change of polymer induced by gas absorption.The fabrication of the sensors incorporates a process where Polymer A(Polyolefin),Polymer B(Fluorocarbon polymer)Polymer C(Acrylic resin),and Polymer D(Amino polymer),are deposited within silicon slits,demonstrating their distinct responses to various vapor species.These sensors show swift response times and efficient recovery periods,which makes them promising for real-time multiple gas and smell monitoring applications.An array of four nanomechanical sensors with polymers shows high repeatability and sensitivity when subjected to multiple gas exposure and turn-off cycles.The gas sensor arrays,effectively monitoring fish quality over several days,suggest a potential for determining optimal storage and early spoilage detection in perishables.The study demonstrates that the nanomechanical sensor array can accurately distinguish between different gas concentrations using principal component analysis,paving the way for real-time,automated multiple gas detection and analysis without human intervention.
文摘This paper presents a new face detection approach to real-time applications, which is based on the skin color model and the morphological filtering. First the non-skin color pixels of the input image are removed based on the skin color model in the YC rC b chrominance space, from which we extract candidate human face regions. Then a mathematical morphological filter is used to remove noisy regions and fill the holes in the candidate skin color regions. We adopt the similarity between the human face features and the candidate face regions to locate the face regions in the original image. We have implemented the algorithm in our smart media system. The experiment results show that this system is effective in real-time applications.
文摘A new type of intelligent recolser controller installed on the outdoor rod is developed, which is mainly composed of microcontroller of Intel 87C196KC 20 and CPLD devices. This controller integrates all the functions of measuring, controlling, protection, fault diagnosis, communication, remote controlled operation and self power devices with infra red remote control devices as a unit. The controller applies the distributed structure, field concentration line and intelligent technology to seal up the synthetic servomechanisms such as the microcomputer based protection and measuring devices in the second stage of the mini out door transformer substation, which are distributed on the outdoor circuit switches on the spot and formed as a whole. Therefore, this technology can transform a large number of ordinary homemade SF 6 circuit beaker and vacuum circuit breaker into intelligent circuit recloser, thus replacing the expensive imported automatic circuit recolser.
基金National Engineering Research Center of UHV Technology and New Electrical Equipment Basis of China Southern Power Grid Research Institute Co.,Ltd,Grant/Award Number:NERCUTNEEB-2022-KF-08。
文摘Accurately identifying the location and type of internal defects in gas-insulated switchgear(GIS)is a challenge.To address this challenge,this study proposes a novel method for the nondestructive detection of GIS internal defects.This method is based on x-ray digital radiography(X-DR)technology and an improved real-time models for object detection(RTMdet)algorithm,namely GIS-specific localised internal defect-RTMdet.Firstly,the X-DR images of GIS are preprocessed by dynamic limit adaptive histogram equalisation algorithm to improve the images contrast.Then,a convolution shuffle upsample module for upsampling is proposed,which enlarges the defect feature map by multi-convolution and pixel shuffling,reduces the information loss,and enhances the interaction between the feature information.Finally,both the multi-channel attention net and the global attention mechanism are integrated into the neck network for enhancing local feature extraction and global information association.Experiments demonstrate that the pro-posed method achieves a mean average precision@0.5:0.95 of 94.9%,showcasing excellent overall performance and generalisation ability,and is more suitable for accurate nondestructive detection of internal defects of GIS in complex scenarios.
基金National Natural Science Foundation of China(12134004,62425503,12204178,12274141).
文摘Mid-infrared(MIR)spectroscopy is instrumental in addressing gas molecule-related environmental and ecologi-cal challenges.Especially,massively parallel sensing capability is critical to multi-species molecules analysis,en-abling the demands for various MIR gas characterizations.However,real-time,high-accuracy parallel sensing for multiple gases remains a significant challenge due to the limitations in laser bandwidth and sampling speed.Here,we present a broadband MIR dual-comb spectrometer for the simultaneous detection of multiple greenhouse gases.This MIR spectrometer employs a scheme of difference frequency generation(DFG),directly producing a wide spectrum spanning 3.2–4.7μm with over 300,000 comb-tooth-resolved frequency lines at a 100 MHz resolution.In addition,we demonstrated the parallel detection of four mixed gas molecules(CH_(4),C_(2)H_(2),CO,and N_(2)O),in which the absorptions were in excellent agreement with HITRAN database.This broadband MIR dual-comb spectrometer is promising to be integrated with only fiber devices and periodically poled lithium niobate waveguides,providing a high-precision,high-efficiency approach for massively parallel sensing in atmos-pheric or industrial monitoring.
文摘Background:Despite the high prevalence of strongyloidiasis in the Laotian population,Laotian hospitals still lack diagnostic capacity to appropriately diagnose Strongyloides stercoralis infections.This cross-sectional hospital-based study was conducted to assess the prevalence of Strongyloides stercoralis infection among hospitalized patients treated at Mahosot Hospital,the primary reference hospital of Lao People’s Democratic Republic(Lao PDR),and to validate feasible methods for diagnosing S.stercoralis infection at hospital’s laboratory.Methods:Between September and December 2018,stool samples of 104 inpatients were investigated for S.stercoralis infection by wet smear,Baermann technique,Koga Agar plate culture(KAPC),and real-time detection polymerase chain reaction(RTD-PCR)at the Infectious Diseases Ward of the Mahosot Hospital in Vientiane.The sensitivity,the specificity,the negative predictive value(NPV)of each diagnostic test,as well as their combination(s)was calculated using a composite reference standard(CRS).The correlation of the different test methods was assessed by chi-square or Fisher’s exact test.Cohen’s kappa coefficient was used to assess the diagnostic agreement of the different test methods.Results:The overall prevalence of S.stercoralis infections among the study population was 33.4%.The cumulative infection prevalence statistically significantly increased from the lowest age group of 40 years and below(22.4%),to the medium(40.0%)and to the oldest age group of 61 year and above(72.7%)(P=0.003).The cumulative infection prevalence of CRS was considerably higher in male(40.4%)compared to female patients(28.1%),but not statistically different(P=0.184).The diagnostic sensitivity of Baermann technique,KAPC,RTD-PCR,and the combination of Baermann technique and KAPC were 60.0,60.0,74.3,and 77.1%,respectively.Only 13 patients(37.1%)of the total 35 S.stercoralis patients diagnosed with any technique had a simultaneously positive diagnostic test with Baermann,KAPC and RTD-PCR.Conclusions:We identified Baermann technique and KAPC to be currently the most feasible and implementable standard methods for diagnosing S.stercoralis at a hospital setting such as Mahosot Hospital and provincial and district hospitals in Lao PDR and other low-and middle income countries in Southeast Asia.Trial registration:This study was approved by the National Ethics Committee for Health Research in Lao PDR(reference no.083/NECHR)and by the Ethics Committee Northwest and Central Switzerland(reference no.2018–00594).
