To automatically detecting whether a person is wearing mask properly,we propose a face mask detection algorithm based on hue-saturation-value(HSV)+histogram of oriented gradient(HOG)features and support vector machine...To automatically detecting whether a person is wearing mask properly,we propose a face mask detection algorithm based on hue-saturation-value(HSV)+histogram of oriented gradient(HOG)features and support vector machines(SVM).Firstly,human face and five feature points are detected with RetinaFace face detection algorithm.The feature points are used to locate to mouth and nose region,and HSV+HOG features of this region are extracted and input to SVM for training to realize detection of wearing masks or not.Secondly,RetinaFace is used to locate to nasal tip area of face,and YCrCb elliptical skin tone model is used to detect the exposure of skin in the nasal tip area,and the optimal classification threshold can be found to determine whether the wear is properly according to experimental results.Experiments show that the accuracy of detecting whether mask is worn can reach 97.9%,and the accuracy of detecting whether mask is worn correctly can reach 87.55%,which verifies the feasibility of the algorithm.展开更多
The explosive demands for facial masks as vital personal protection equipment(PPE)in the wake of Covid-19 have challenged many industries and enterprises in technology and capacity,and the piezoelectric ceramic(PZT)tr...The explosive demands for facial masks as vital personal protection equipment(PPE)in the wake of Covid-19 have challenged many industries and enterprises in technology and capacity,and the piezoelectric ceramic(PZT)transducers for the production of facial masks in the welding process are in heavy demand.In the earlier days of the epidemic,the supply of ceramic transducers cannot meet its increasing demands,and efforts in materials,development,and production are mobilized to provide the transducers to mask producers for quick production.The simplest solution is presented with the employment of Rayleigh-Ritz method for the vibration analysis,then different materials can be selected to achieve the required frequency and energy standards.The fully tailored method and results can be utilized by the engineers for quick development of the PZT transducers to perform precise function in welding.展开更多
＂We Are the Furrow of His Brow＂ is the graffiti altered from ＂Beware of the Furrow of His Brow＂ or ＂The Furrow of His Brow＂ on the hood of an oven in a separated black town Ruby. Young people of Ruby change the ...＂We Are the Furrow of His Brow＂ is the graffiti altered from ＂Beware of the Furrow of His Brow＂ or ＂The Furrow of His Brow＂ on the hood of an oven in a separated black town Ruby. Young people of Ruby change the words because they feel regretted contriving to shoot an assumed guilty woman living in the nearby convent. However, whether the woman Consolata and the other four women at the convent are dead remains mysterious. There are some descriptions of magics in Paradise in which the most magical abilities are Connie＇s ＂bat vision＂ and ＂stepping in＂. This paper demonstrates the ways that Morrison manifests magic realism in Paradise including multiple narrative timelines, ambiguous writing, reconstituted marginal figures and naturally blended reality. Primarily in thefour ways Morrison presents how she utilizes magic realism genre to depict the changeable world penetrating through the appearance.展开更多
基金National Natural Science Foundation of China(No.519705449)。
文摘To automatically detecting whether a person is wearing mask properly,we propose a face mask detection algorithm based on hue-saturation-value(HSV)+histogram of oriented gradient(HOG)features and support vector machines(SVM).Firstly,human face and five feature points are detected with RetinaFace face detection algorithm.The feature points are used to locate to mouth and nose region,and HSV+HOG features of this region are extracted and input to SVM for training to realize detection of wearing masks or not.Secondly,RetinaFace is used to locate to nasal tip area of face,and YCrCb elliptical skin tone model is used to detect the exposure of skin in the nasal tip area,and the optimal classification threshold can be found to determine whether the wear is properly according to experimental results.Experiments show that the accuracy of detecting whether mask is worn can reach 97.9%,and the accuracy of detecting whether mask is worn correctly can reach 87.55%,which verifies the feasibility of the algorithm.
基金supported in part by the National Natural Science Foundation of China(No.11672142)the Technology Innovation 2025 Program of the Municipality of Ningbo(No.2019B10122)。
文摘The explosive demands for facial masks as vital personal protection equipment(PPE)in the wake of Covid-19 have challenged many industries and enterprises in technology and capacity,and the piezoelectric ceramic(PZT)transducers for the production of facial masks in the welding process are in heavy demand.In the earlier days of the epidemic,the supply of ceramic transducers cannot meet its increasing demands,and efforts in materials,development,and production are mobilized to provide the transducers to mask producers for quick production.The simplest solution is presented with the employment of Rayleigh-Ritz method for the vibration analysis,then different materials can be selected to achieve the required frequency and energy standards.The fully tailored method and results can be utilized by the engineers for quick development of the PZT transducers to perform precise function in welding.
文摘＂We Are the Furrow of His Brow＂ is the graffiti altered from ＂Beware of the Furrow of His Brow＂ or ＂The Furrow of His Brow＂ on the hood of an oven in a separated black town Ruby. Young people of Ruby change the words because they feel regretted contriving to shoot an assumed guilty woman living in the nearby convent. However, whether the woman Consolata and the other four women at the convent are dead remains mysterious. There are some descriptions of magics in Paradise in which the most magical abilities are Connie＇s ＂bat vision＂ and ＂stepping in＂. This paper demonstrates the ways that Morrison manifests magic realism in Paradise including multiple narrative timelines, ambiguous writing, reconstituted marginal figures and naturally blended reality. Primarily in thefour ways Morrison presents how she utilizes magic realism genre to depict the changeable world penetrating through the appearance.
