Abstract: A digital twin based method for monitoring behavior of a passenger on an escalator includes: first, constructing a digital twin virtual scene of the escalator carrying the passenger; constructing a virtual person model in a physics engine, generating various types of risky behavior in reality, and outputting different types of behavior of a virtual person; second, through a human posture recognition method for monitoring behavior of a passenger, extracting a feature map as an input by means of a visual geometry group 19 (VGG19) pre-training network, to enter part affinity fields (PAFs) and a part confidence map (PCM), so as to complete recognition of human postures; classifying the human postures with a support vector machine; and performing emergency stop control on the escalator under risky behavior of the passenger according to a result of posture classification.

Abstract: A physiological detection device includes system including a first array PPG detector, a second array PPG detector, a display and a processing unit. The first array PPG detector is configured to generate a plurality of first PPG signals. The second array PPG detector is configured to generate a plurality of second PPG signals. The display is configured to show a detected result of the physiological detection system. The processing unit is configured to convert the plurality of first PPG signals and the plurality of second PPG signals to a first 3D energy distribution and a second 3D energy distribution, respectively, and control the display to show an alert message.

Abstract: A floating structure and basic module of a floating structure are presented. The floating structure includes multiple lower floating bodies, an upper structure, and intermediate connection structures. The multiple lower floating bodies include multiple distributed elongated floating bodies. The floating bodies are spaced from each other by a certain distance. The sum of the displacement volumes of the floating bodies is greater than the displacement volume when the floating structure as a whole is fully loaded. The intermediate connection structures include at least multiple connection structures in a first direction, the first direction intersecting the horizontal plane. A connection structure in the first direction corresponds to a single elongated floating body connected to three or more spaced structures. The cross-section width of each intermediate connection structure in the horizontal direction is less than the width of the corresponding elongated floating body.

Abstract: A highly safe large floating structure, and a basic module of a very large floating structure, includes multiple lower floating bodies, an upper structure, and intermediate connection structures. The multiple lower floating bodies include multiple distributed strip-shaped floating bodies. The floating bodies are spaced from each other by a certain distance. The sum of the displacement volumes of the floating bodies is greater than the displacement volume when the floating structure as a whole is fully loaded. The intermediate connection structures include at least multiple connection structures in a first direction, the first direction intersecting the horizontal plane. A connection structure in the first direction corresponds to a single strip-shaped floating body connected to three or more spaced structures. The cross-section width of each intermediate connection structure in the horizontal direction is less than the width of the corresponding strip-shaped floating body.

Abstract: A head-up display with variable focal length includes a projector which provides a beam with image, a magnifier lens module which is disposed on the route of the beam, and an array of lens which is movably disposed between the projector and the magnifier lens module. The beam forms an inter-image after passing the array of lens, then forms a virtual image after passing the magnifier lens module. To change the position of the virtual image, adjust the relative position between the array of lens and the magnifier lens module. A dispersion angle of the array of lens is ?d, a magnification of the magnifier lens module is M, a distance between the virtual image and user's eyes is VID, a visible range of user's eyes is Et, and satisfies the relationship as following: ?d=M*2*cot?1 (2VID/Et).

Abstract: A head-up display with variable focal length includes a projector which provides a beam with image, a magnifier lens module which is disposed on the route of the beam, and an array of lens which is movably disposed between the projector and the magnifier lens module. The beam forms an inter-image after passing the array of lens, then forms a virtual image after passing the magnifier lens module. To change the position of the virtual image, adjust the relative position between the array of lens and the magnifier lens module. A dispersion angle of the array of lens is ?d, a magnification of the magnifier lens module is M, a distance between the virtual image and user's eyes is VID, a visible range of user's eyes is Et, and satisfies the relationship as following: ?d=M*2*cot?1 (2VID/Et).