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    Abstract:
    To reduce the stitching error of circularity measurement of small cylindrical workpieces (Diameter less than 3 mm) by the segmenting-stitching method, arc contour extraction is analyzed in this paper. The coordinates of cross-sectional circle of a small cylindrical part are segmented into several equal arcs to be obtained by a two-dimensional coordinate measuring machine. The circularity contour of the small cylindrical part can be formed by stitching a series of arc contours which are calculated by the obtained arc coordinate data. Due to the different measuring pressure angles of different measuring positions, the accuracy of obtained arc coordinate points is different. The bigger the pressure angle is, the accurate the obtained arc coordinate data are. The ex-periments show that the accuracy of two ends of the arc data is not as good as the central part. Therefore, the two ends of the obtained arc data are appropriately to be cut off, namely, only the central part of the arc data are extracted to be used for the stitching. As a result, the mean value of the matching coefficient is enhanced by 12%, the deviation between the overlap part of the neighbouring arc contour is reduced by 26%, and the average curvature of the arc contours is improved with the extraction method. Thus, the accuracy of the stitched cir-cularity contour can be improved by this extraction procedure in the segmenting-stitching method for the cir-cularity measurement of the small cylindrical parts.
    Abstract:
    This study aims to develop a low-cost refractometer for measuring the sucrose content of fruit juice, which is an important factor affecting human health. While laboratory-grade refractometers are expensive and unsuitable for personal use, existing low-cost commercial options lack stability and accuracy. To address this gap, we propose a refractometer that replaces the expensive CCD sensor and light source with a conventional LED and a reasonably priced CMOS sensor. By analyzing the output waveform pattern of the CMOS sensor, we achieve high precision with a personal-use-appropriate accuracy of 0.1%. We tested the proposed refractometer by conducting 100 repeated measurements on various fruit juice samples, and the results demonstrate its reliability and consistency. Running on a 48 MHz ARM processor, the algorithm can acquire data within 0.2 seconds. Our low-cost refractometer is suitable for personal health management and small-scale production, providing an affordable and reliable method for measuring sucrose concentration in fruit juice. It improves upon the existing low-cost options by offering better stability and accuracy. This accessible tool has potential applications in optimizing the sucrose content of fruit juice for better health and quality control.
    Abstract:
    Rotational Vision System (RVS) is a common active vision system with only rotational degrees of freedom. Usually, the degree of freedom for rotation is provided by the turntable and pan head. Or the hand to eye (EIH) structure in articulated arm robots. Due to assembly deviations and manufacturing accuracy limitations, the ideal assumption that the rotation axis is fully aligned with the coordinate axis of the local camera is mostly violated. To address this issue, we propose a generalized deviation model that specifies a rotation axis that connects the rotational motion of the platform with the external orientation (EO) of the camera. On this basis, we propose a heuristic estimation algorithm to minimize global reprojection errors and fit circles in space under constraints of global optimization. The experiment shows that the translation and tilt average reprojection errors of dynamic EO reconstruction based on the reprojection error method are 0.14 and 0.08 pixels, respectively. In the absence of angle measurement, the results of the circle fitting method are similar to them (with a relative error of about 2%), meeting the application requirements of general visual measurement.
    Abstract:
    In order to allow the guardians to monitor the physiological parameters of the infant more intuitively and to be able to respond to sudden irregularities in the pulse rate, abnormal blood oxygen, high or low body temperature and other conditions, and to facilitate communication with the medical staff or to request assistance in treatment, an STM32 microcontroller-based infant health monitoring system is designed. The digital signal acquisition module for pulse, blood oxygen and body temperature acquire the raw data, and the microcontroller performs algorithmic processing to display the physiological parameters such as pulse, blood oxygen and body temper-ature of the infant, and configures the threshold alarms for the physiological parameters by means of a keypad module. Finally, the test results are compared and tested against the standard physiological parameters of infants and children to verify that the system meets the requirements of medical precision and accuracy.
    Abstract:
    In order to address the issues of the current sheep face pain detection algorithm under complex environments with poor detection accuracy and complex models, this paper proposes a two-stage method of sheep face pain detection based on light yolov5s. First, the weights of the yolov5s model are reduced by combining the Ghostnet structure, feature fusion is performed using the BiFPN structure and the ODConv join to improve detection accuracy. The experimental results show that the number of parameters and complexity of the optimized model are reduced by 38.03% and 50.94%, respectively, compared with the original model, and the accuracy of recognizing sheep faces is improved by 0.2% and the recall rate is increased by 1%. Compared to current mainstream algorithms such as yolov4 tiny and SSD, it not only significantly reduces the number of parameters but also has a better detection performance. Second, pain detection of sheep faces recognised by lightweight yolov5s was carried out by MobileNetV2, and experimental results showed that MobileNetV2 achieved a mean classification accuracy of over 98% for painful sheep, and this illustrates that this two-stage sheep face pain recognition research method has great application value for sheep health breeding.
    Abstract:
    With the improvement of the degree of aging, the traditional pension model can no longer meet the growing needs of the elderly. Therefore, it is necessary to use the intelligent means of information technology to improve the level of pension services. This paper will integrate multi-sensor fusion technology, NB-IoT communication technology and cloud platform technology to develop and design a smart pension online monitoring system to realize real-time collection of human health and motion status information and realize monitoring platform management. In this system, STM32 microcontroller will be used as the main control module, and MAX30102, ADXL345 and DS18B20 sensors will be used to collect the heart rate, blood oxygen, displacement and body temperature of the human body in real time. On the one hand, the communication part is completed by the BC20 Internet of Things module. The data transmission between the terminal detection device and the cloud platform, on the other hand, the HC-42 Bluetooth module is used to complete the data communication with the mobile phone. The test results show that the system can collect and process data accurately in real time and maintain good communication with the cloud platform and mobile phone. The designed system has strong pertinence, easy operation, high reliability and broad development prospects.
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    2017,4(3):14-23, DOI:
    [Abstract] (1708) [HTML] (0) [PDF 13.79 M] (4820)
    Abstract:
    Aiming at the problem of pedestrian bridge vibration measurement, a vibration measurement system of pedestrian bridge with dual magnetic suspension vibrator structure was designed according to absolute vibration measurement principle. The relationship between the magnetic repulsion force of vibrator and its displacement was obtained by the experimental method and the least square fitting method. The vibration equations of two magnetic suspension vibrators were deduced respectively, and the measurement sensitivity of the system was deduced. The amplitude-frequency characteristic of the system was studied. A simulation model of vibrator measurement system with double magnetic suspension vibrator was established. The analysis shows that the sensitivity of the vibration measurement system with double magnetic suspension vibrator is higher than that with single magnetic suspension vibrator. The four vibration waveforms were measured, that is, no one passes through a pedestrian bridge, there are cars running under the pedestrian bridge, single pedestrian passes through the pedestrian bridge and multiple pedestrians pass through the pedestrian bridge. The multi-scale one-dimensional wavelet decomposition function was used to analyze the vibration signals. The vibration characteristics were obtained using one dimension wavelet decomposition function under four different conditions. Finally, the vibration waveforms of four cases were reconstructed. The measured results show that the vibration measurement system of pedestrian bridge with double magnetic suspension vibrator structure has high measurement sensitivity. The design has a certain value to monitor a pedestrian bridge.
    2017,4(3):59-68, DOI:
    [Abstract] (1307) [HTML] (0) [PDF 10.00 M] (3980)
    Abstract:
    Crack of conductive component is one of the biggest threats to daily production. In order to detect the crack on conductive component, the pulsed eddy current thermography models were built according to different materials with the cracks based on finite element method (FEM) simulation. The influence of the induction heating temperature distribution with the different defect depths were simulated for the carbon fiber reinforced plastic (CFRP) materials and general metal materials. The grey value of image sequence was extracted to analyze its relationship with the depth of crack. Simulative and experimental results show that in the carbon fiber reinforced composite materials, the bigger depth of the crack is, the larger temperature rise of the crack during the heating phase is; and the bigger depth of the crack is, the faster the cooling rate of the crack during the cooling phase is. In general metal materials, the smaller depth of the crack is, the lager temperature rise of the crack during the heating phase is; and the smaller depth of the crack is, the faster the cooling rate of crack during the cooling phase is.
    2017,4(3):7-13, DOI:
    [Abstract] (2002) [HTML] (0) [PDF 8.76 M] (3859)
    Abstract:
    A novel phase-locked loop (PLL) -based closed-loop driving circuit with ultra-low-noise trans-impedance amplifier (TIA) is proposed. The TIA is optimized to achieve ultra-low input-referred current noise. To track drive-mode resonant frequency and reduce frequency jitter of actuation voltage, a PLL-based driving technique is adopted. Implemented on printed circuit board (PCB), the proposed driving loop has successfully excited MEMS element into resonance, with a settling time of 3s. The stable frequency and amplitude of TIA output voltage are 10.14KHz and 800mVPP, respectively. With sense-channel electronics, the gyroscope exhibits a scale factor of 0.04mV/°/s and a bias instability of 57.6°/h, which demonstrates the feasibility of the proposed driving circuit.
    2017,4(3):24-34, DOI:
    [Abstract] (1853) [HTML] (0) [PDF 8.44 M] (3205)
    Abstract:
    The contamination proposed in this paper is a defect on the surface of ice cream bar, which is a serious security threat. So it is essential to detect this defect before launched on the market. A detection method of contamination defect on the ice cream bar surface is proposed, which is based on fuzzy rule and absolute neighborhood feature. Firstly, the ice cream bar surface is divided into several sub-regions via the defined adjacent gray level clustering method. Then the alternative contamination regions are extracted from the sub-regions via the defined fuzzy rule. At last, the real contamination regions are recognized via the relationship between absolute neighborhood gray feature and default threshold. The algorithm was tested in the self-built image database SUT-D. The results show that the accuracy of the method proposed in this paper is 97.32 percent, which increases 2.68 percent at least comparing to the other typical algorithms. It indicates that the superiority proposed in this paper, which is of actual use value.
    [Abstract] (579) [HTML] (0) [PDF 3.00 M] (2944)
    Abstract:
    In this paper, we aim to propose a novel and effective iris segmentation method that is robust to uneven light intensity and different kinds of noises such as occlusion by light spots, eyelashes, eyelids, spectacle-frame, etc. Unlike previous methods, the proposed method makes full use of gray intensities of the iris image. Inspired by the matting algorithm, a premier assumption is made that the foreground and background images of the iris image are both locally smooth. According to the RST algorithm, trimaps are built to provide priori information. Under the assumption and priori, the optimal alpha matte can be obtained by least square loss function. A series of effective post processing methods are applied to the alpha image to obtain a more precise iris segmentation. The experiment on CASIA-iris-thousand database shows that the proposed method achieves a much better performance than conventional methods. Our experimental results achieve 20.5% and 26.4%, more than the well-known integro-differential operator and edge detection combined with Hough transform on iris segmentation rate respectively. The stability and validity of the proposed method is further demonstrated through the complementary experiments on the challenging iris images.
    2014,1(3):67-74, DOI:
    [Abstract] (1090) [HTML] (0) [PDF 1.48 M] (2848)
    Abstract:
    Resonant temperature sensors have drawn considerable attention for their advantages such as high sensitivity, digitized signal output and high precision. This paper presents a new type of resonant temperature sensor, which uses capacitive micromachined ultrasonic transducer (CMUT) as the sensing element. A lumped electro-mechanical-thermal model was established to show its working principle for temperature measurement. The theoretical model explicitly explains the thermally induced changes in the resonant frequency of the CMUT. Then, the finite element method was used to further investigate the sensing performance. The numerical results agree well with the established analytical model qualitatively. The numerical results show that the resonant frequency varies linearly with the temperature over the range of 20 ℃ to 140℃ at the first four vibrating modes. However, the first order vibrating mode shows a higher sensitivity than the other three higher modes. When working at the first order vibrating mode, the temperature coefficient of the resonance frequency (TCf) can reach as high as -1114.3 ppm/℃ at a bias voltage equal to 90% of the collapse voltage of the MCUT. The corresponding nonlinear error was as low as 1.18%. It is discovered that the sensing sensitivity is dependent on the applied bias voltages. A higher sensitivity can be achieved by increasing the bias voltages.
    [Abstract] (545) [HTML] (0) [PDF 1.51 M] (2799)
    Abstract:
    For the hand-eye calibration of the vision service robot, the traditional hand-eye calibration technology can’t be realized which because the service robot is independently developed and there is no teaching device to feed back the pose in-formation of the service robot in real time. In this paper, a hand-eye calibration method based on ROS (Robot Operating System) is proposed. In this method, ROS system is used to accurately control the arm of the service robot to rotate in different positions for many times. Meanwhile, the head camera of the service robot takes images of a fixed point in the scene. Then, the nonlinear equations were established according to the homography matrix of the two images and the position and pose information of the ROS system, and the accurate hand-eye relationship was optimized by the least square method. Finally, an experimental platform is built and the proposed hand-eye calibration method is verified. The experiment results show that the method is easy to operate, simple algorithm and correct result, which verifies the ef-fectiveness of the algorithm and provides conditions for the realization of humanoid grasping of visual service robot.
    [Abstract] (426) [HTML] (0) [PDF 2.27 M] (2747)
    Abstract:
    In the background of “double carbon,” vigorously developing new energy is particularly important. Wind power is an important clean energy source. In the field of new energy, wind power scale is also expanding. With the wind turbine, the probability of large-scale blade damage is also increasing. Because the large wind turbine blade crack detection cost is high and because of the poor working environment, this paper proposes a wind turbine blade surface defect detection method based on UAV acquisition images and digital image processing. The application of weighted averages to achieve grayscale processing, followed by median filtering to achieve image noise reduction, and an improved histogram equalization algorithm is proposed and used for the characteristics of the UAV acquisition images, which enhances the image by limiting the contrast adaptive histogram equalization algorithm to make the details at the target area and defects more clear and complete, and improves the detection efficiency. The detection of the blade surface is achieved by separating and extracting the feature information from the defects through image foreground segmentation, threshold processing, and framing by the connected domain. The validity and accuracy of the proposed method in leaf detection were verified by experiments.
    [Abstract] (692) [HTML] (0) [PDF 6.19 M] (2731)
    Abstract:
    Magnetic field measurement plays an extremely important role in material science, electronic engineering, power system and even industrial fields. In particular, magnetic field measurement provides a safe and reliable tool for in-dustrial non-destructive testing. The sensitivity of magnetic field measurement determines the highest level of detec-tion. The diamond nitrogen-vacancy (NV) color center is a new type of quantum sensor developed in recent years. The external magnetic field will cause Zeeman splitting of the ground state energy level of the diamond NV color center. Optical detection magnetic resonance (ODMR), using a microwave source and a lock-in amplifier to detect the resonant frequency of the NV color center, and finally the change of the resonant frequency can accurately calcu-late the size of the external magnetic field and the sensitivity of the external magnetic field change. In the experiment, a diamond containing a high concentration of NV color centers is coupled with an optical fiber to realize the prepara-tion of a magnetic field scanning probe. Then, the surface cracks of the magnetized iron plate weld are scanned, and the scanning results are drawn into a two-dimensional magnetic force distribution map, according to the magnetic field gradient change of the magnetic force distribution map, the position and size of the crack can be judged very accurately, which provides a very effective diagnostic tool for industrial safety.
    [Abstract] (486) [HTML] (0) [PDF 1.62 M] (2727)
    Abstract:
    To improve intelligent vehicle drive performance and avoid vehicle side-slip during target path tracking, a linearized four-wheel vehicle model is adopted as a predictive control model, and an intelligent vehicle target path tracking method based on a competitive cooperative game is proposed. The design variables are divided into different strategic spaces owned by each player by calculating the affecting factors of the design variables with objective functions and fuzzy clustering. Based on the competitive cooperative game model, each game player takes its payoff as a mono-objective to optimize its own strategic space and obtain the best strategy to deal with others. The best strategies were combined into the game strategy set. Considering the front wheel angle and side slip angle increment constraint, tire side-slip angle, and tire side slip deflection dynamics, it took the path tracking state model was used as the objective, function and the calculation was validated by competitive cooperative game theory. The results demonstrated the effectiveness of the proposed algorithm. The experimental results show that this method can track an intelligent vehicle quickly and steadily and has good real-time performance.
    2014,1(1), DOI:
    [Abstract] (807) [HTML] (0) [PDF 8.46 M] (2605)
    Abstract:
    Surface acoustic wave (SAW) resonator used as wireless sensor was characterized and the parameters of its MBVD ((Modified Butterworth-Van Dyke) model were extracted versus temperature. The extracted parameters lead to evaluate the resonator performances in terms of Temperature coefficient of frequency (TCF) and quality factor (Q). An antenna was then associated with the SAW resonator and the entire system has been characterized and modeled. The good agreement experiment-simulation allows to define the optimum operating conditions of the wireless sensor.
    2017,4(3):54-58, DOI:
    [Abstract] (1946) [HTML] (0) [PDF 2.44 M] (2589)
    Abstract:
    According to the problem that the selection of traditional PID control parameters is too complicated in evaporator of Organic Rankine Cycle system (ORC), an evaporator PID controller based on BP neural network optimization is designed. Based on the control theory, the model of ORC evaporator is set up. The BP algorithm is used to control the , and parameters of the evaporator PID controller, so that the evaporator temperature can reach the optimal state quickly and steadily. The MATLAB software is used to simulate the traditional PID controller and the BP neural network PID controller. The experimental results show that the , and parameters of the BP neural network PID controller are 0.5677, 0.2970, and 0.1353, respectively. Therefore, the evaporator PID controller based on BP neural network optimization not only satisfies the requirements of the system performance, but also has better control parameters than the traditional PID controller.
    2017,4(3):35-39, DOI:
    [Abstract] (1589) [HTML] (0) [PDF 3.21 M] (2542)
    Abstract:
    Using the temperature compensation and structure optimization design technology, developed the TBQ-2-B type standard pyranometer on the original pyranometer basis, its stability is better than 2%, reached the international standard ISO 9060 and the World Meteorological Organization (WMO) instruments and methods of observation Committee (CIMO) on the first level pyranometer request. Over the years, comparing with our national solar radiation standard (absolute cavity radiometer), its performance is very stable. As a working standard pyranometer, it has been used for more than twenty years in the field of metrological calibration of meteorological radiation instruments.
    2015,2(1):17-26, DOI:
    [Abstract] (899) [HTML] (0) [PDF 3.70 M] (2435)
    Abstract:
    Abstract: This manuscript briefly summarizes the development trends and recent research focus of the star tracker. And the relevant technologies about dynamic performance of the star tracker are analyzed and discussed. These can provide reference for the star tracker and attitude measurement device researchers.
    2017,4(3):1-6, DOI:
    [Abstract] (2068) [HTML] (0) [PDF 1.84 M] (2227)
    Abstract:
    Solar thermal and photovoltaic applications are the most widely used and the most successful way of commercial development in solar energy applications. Observation and assessment of solar thermal and photovoltaic resources are the basis and key of their large-scale development and utilization. Using the observational data carried out from Beijing southern suburbs observation station of China Meteorological Administration in summer of 2009, preliminary solar thermal and photovoltaic resources characteristics for different weather conditions, different angle and different directions are analyzed. The results show that: (1) In sunny, cloudy or rainy weather conditions, both of solar thermal and photovoltaic sensors daily irradiance have consistent change in trend. Solar thermal irradiance is larger than photovoltaic. Under sunny conditions, solar thermal global radiation has about 2.7% higher than the photovoltaic global radiation. Under cloudy weather conditions, solar thermal global radiation has about 3.9% higher than the photovoltaic. Under rainy weather conditions, solar thermal global radiation has about 20% higher than the photovoltaic. (2) For different inclined plane daily global radiation, southern latitude -15 °incline is the maximum and southern vertical surface is the minimum. The order from large to small is southern latitude-15 ° incline, southern latitude incline, southern latitude+15 °incline, horizontal surface and southern vertical surface. Southern latitude -15 °incline global radiation has about 41% higher than the southern vertical surface. (3) For different orientation vertical surface daily global radiation, southern vertical surface is the maximum and western vertical surface is the minimum, which eastern vertical surface is in the middle. Southern vertical surface global radiation has about 20% higher than the western vertical surface.
    Abstract:
    In the process of crowd movement, pedestrians are often affected by their neighbors. In order to describe the consistency of adjacent individuals and collectivity of a group, this paper learns from the rules of the flocking behavior, such as segregation, alignment and cohesion, and proposes a method for crowd motion simulation based on the Boids model and social force model. Firstly, the perception area of individuals is divided into zone of segregation, alignment and cohesion. Secondly, the interactive force among individuals is calculated based upon the zone information, velocity vector and the group information. The interactive force among individuals is the synthesis of three forces: the repulsion force to avoid collisions, the alignment force to keep consistent with the velocity direction, and the attractive force to get close to the members of group. In segregation and alignment areas, the repulsion force and alignment force among pedestrians are limited by visual field factors. Finally, the interactive force among individuals, the driving force of destination and the repulsion force of obstacles work together to drive the behavior of crowd motion. The simulation results show that the proposed method can not only effectively simulate the interactive behavior between adjacent individuals but also the collective behavior of group.
    Abstract:
    To keep coal workers away from the hazardous area with frequent accidents such as the roof fall and rib spalling in an underground coalmine, we put forward the solution with robotized self-moving anchor-supporting unit. The existing research shows that the surrounding rock of the roadway has self-stability, and the early or late support is not conducive to the safe and reliable support of the roadway, so there is a problem of support opportunity. In order to study the supporting effect and the optimal supporting time of the above solution, we established the mechanical coupling model of surrounding rock and advance support, and investigated the surrounding rock deformation and advance support pressure distribution under different reserved roof subsidence by using the numerical simulation software FLAC3D. The results show that the deformation of surrounding rock increases and finally tends to a stable level with the increase of pre settlement of roadway roof, and when the pre settlement of roof is between 8-15mm, the vertical pressure of the top beam of advance support reaches the minimum value, about 0.58MPa. Based on the above research, we put forward the optimum supporting time in roadway excavation, and summarized the evaluation method based on the mechanical coupling model of surrounding rock-advance support.
    Abstract:
    A supportive mobile robot for assisting the elderly is an emerging requirement mainly in countries like Japan where population ageing become relevant in near future. Falls related injuries are considered as a critical issue when taking into account the physical health of older people. A personal assistive robot with the capability of picking up and carrying objects for long/short distances can be used to overcome or lessen this problem. Here, we design and introduce a 3D dynamic simulation of such an assistive robot to perform pick and place of objects through visual recognition. The robot consists of two major components; a robotic arm or manipulator to do the pick and place, and an omnidirectional wheeled robotic platform to support mobility. Both components are designed and operated according to their kinematics and dynamics and the controllers are integrated for the combined performance. The objective was to improve the ac-curacy of the robot at a considerably high speed. Designed mobile manipulator has been successfully tested and sim-ulated with a stereo vision system to perform object recognition and tracking in a virtual environment resembling aroom of an elderly care. The tracking accuracy of the mobile manipulator at an average speed of 0.5m/s is 90% and is well suited for the proposed application.
    2015,2(1):65-74, DOI:
    Abstract:
    Abstract: Organic ferroelectric memory devices based on field effect transistors that can be configured between two stable states of on and off have been widely researched as the next generation data storage media in recent years. This emerging type of memory devices can lead to a new instrument system as a potential alternative to previous non-volatile memory building blocks in future processing units because of their numerous merits such as cost-effective process, simple structure and freedom in substrate choices. This bi-stable non-volatile memory device of information storage has been investigated using several organic or inorganic semiconductors with organic ferroelectric polymer materials. Recent progresses in this ferroelectric memory field, hybrid system have attracted a lot of attention due to their excellent device performance in comparison with that of all organic systems. In this paper, a general review of this type of ferroelectric non-volatile memory is provided, which include the device structure, organic ferroelectric materials, electrical characteristics and working principles. We also present some snapshots of our previous study on hybrid ferroelectric memories including our recent work based on zinc oxide nanowire channels.
    2014,1(1), DOI:
    Abstract:
    As an important and necessary part in the intelligent battery management systems (BMS), the prognostics and remaining useful life (RUL) estimation for lithium-ion batteries attach more and more attractions. Especially, the data-driven approaches use only the monitoring data and historical data to model the performance degradation and assess the health status, that makes these methods flexible and applicable in actual lithium-ion battery applications. At first, the related concepts and definitions are introduced. And the degradation parameters identification and extraction is presented, as the health indicator and the foundation of RUL prediction for the lithium-ion batteries. Then, data-driven methods used for lithium-ion battery RUL estimation are summarized, in which several statistical and machine learning algorithms are involved. Finally, the future trend for battery prognostics and RUL estimation are forecasted.
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