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Real-time body tracking in virtual reality using a Vive tracker
摘要： Due to recent improvements in virtual reality (VR) technology, the number of novel applications for entertainment, education, and rehabilitation has increased. The primary goal of these applications is to enhance the sense of belief that the user is “present” in the virtual environment. By tracking the user’s skeleton in real-time, it is possible to synchronize the avatar’s motions with the user’s motions. Although current common devices implement body tracking to a certain degree, most approaches are limited by either high latency or insufficient accuracy. Due to the lack of positional and rotation data, the current VR applications typically do not represent the user’s motions. In this paper, we present an accurate, low-latency body tracking approach for VR-based applications using Vive Trackers. Using a HTC Vive headset and Vive Trackers, we have been able to create an immersive VR experience, by animating the motions of the avatar as smoothly, rapidly and as accurately as possible. An evaluation showed our solution is capable of tracking both joint rotation and position with reasonable accuracy and a very low end-to-latency of 6.71 ± 0.80 ms . Due to this merely imperceptible delay and precise tracking, our solution can show the movements of the user in real-time in order to create deeper immersion.
关键词： Full-body avatar,Real-time tracking,Inverse kinematics,Low-latency,Virtual reality,HTC Vive tracker
更新于2025-09-10 09:29:36
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Blue-light imaging compared with high-definition white light for real-time histology prediction of colorectal polyps less than 1 centimeter: a prospective randomized study
摘要： Blue-light imaging (BLI) is a new chromoendoscopy technique, potentially useful for differentiating neoplastic from nonneoplastic lesions. The present study was aimed at comparing BLI with high-definition white light (HDWL) in the real-time histology prediction of colon polyps <10 mm.
关键词： Blue-light imaging,real-time histology prediction,high-definition white light,colon polyps
更新于2025-09-10 09:29:36
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In situ FTIR reactor for monitoring gas phase products during a (photo)catalytic reaction in the liquid phase
摘要： Various catalytic and photocatalytic reactions in the liquid phase give rise to gas products. Therefore, the identification and quantification of these products are of high importance and even essential for some reactions. In this communication, a new in situ FTIR reactor is designed and used for analyzing the gas headspace of a (photo)catalytic reaction in solution. It allows the identification and quantification of the gas products of a liquid reaction under operating conditions and in real time. The new reactor has been tested in three representative photocatalytic reactions widely studied as model reactions in the liquid phase, i.e., i) decomposition of formic acid, ii) oxidation of Methylene Blue and iii) reduction of CO2. The validity of the results has been confirmed by analyzing the headspace at the end of the reaction using GC. The new reactor opens the possibility to follow on-line the (photo)catalyst activity. This is useful for ensuring the stability of the catalyst and studying the evolution of the selectivity during the reaction. The non-destructive behavior of the FTIR technique allows its coupling with other techniques for obtaining complementary results. The new reactor setup is easy to handle, to ship, and is very efficient which make it very suitable for performing fast and/or preliminary studies.
关键词： gas phase products,photocatalytic reaction,liquid phase,real-time analysis,FTIR reactor
更新于2025-09-10 09:29:36
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Real-time coherent diffraction inversion using deep generative networks
摘要： Phase retrieval, or the process of recovering phase information in reciprocal space to reconstruct images from measured intensity alone, is the underlying basis to a variety of imaging applications including coherent diffraction imaging (CDI). Typical phase retrieval algorithms are iterative in nature, and hence, are time-consuming and computationally expensive, making real-time imaging a challenge. Furthermore, iterative phase retrieval algorithms struggle to converge to the correct solution especially in the presence of strong phase structures. In this work, we demonstrate the training and testing of CDI NN, a pair of deep deconvolutional networks trained to predict structure and phase in real space of a 2D object from its corresponding far-field diffraction intensities alone. Once trained, CDI NN can invert a diffraction pattern to an image within a few milliseconds of compute time on a standard desktop machine, opening the door to real-time imaging.
关键词： phase retrieval,deep learning,coherent diffraction imaging,real-time imaging,neural networks
更新于2025-09-10 09:29:36
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Implementing a method based on near infrared spectroscopy for the “in-situ” determination of ammonia/water composition in an absorber test bench
摘要： This study presents the first results of composition measurement in an ammonia/water mixture determined at real time using near-infrared (NIR) spectroscopy in an absorber test bench. Two cells were designed and constructed; a static cell for calibrating and a dynamic cell for measuring in the absorber test bench. The ammonia absorption band was not significantly affected by the solution flow rate and neither by small variations in the temperature and pressure. A linear regression model between the absorbance value at 1033 nm and the ammonia concentration was established. This model was used to estimate the concentration in an ammonia/water absorber test bench. The methodology was validated by density measurements of the samples. The value of the mean deviation was 0.0024.
关键词： ammonia/water composition,near-infrared spectroscopy,absorber test bench,real-time measurement
更新于2025-09-10 09:29:36
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Monitoring and tracking the trans-Pacific transport of aerosols using multi-satellite aerosol optical depth composites
摘要： The primary goal of this study was to generate a near-real time (NRT) aerosol optical depth (AOD) product capable of providing a comprehensive understanding of the aerosol spatial distribution over the Pacific Ocean, in order to better monitor and track the trans-Pacific transport of aerosols. Therefore, we developed a NRT product that takes advantage of observations from both low-earth orbiting and geostationary satellites. In particular, we utilize AOD products from the Moderate Resolution Imaging Spectroradiometer (MODIS) and Suomi National Polar-orbiting Partnership (NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) satellites. Then, we combine these AOD products with our own retrieval algorithms developed for the NOAA Geostationary Operational Environmental Satellite (GOES-15) and Japan Meteorological Agency (JMA) Multi-functional Transport Satellite (MTSAT-2) to generate a NRT daily AOD composite product. We present examples of the daily AOD composite product for a case study of trans-Pacific transport of Asian pollution and dust aerosols in mid-March 2014. Overall, the new product successfully tracks this aerosol plume during its trans-Pacific transport to the west coast of North America as the frequent geostationary observations lead to a greater coverage of cloud-free AOD retrievals equatorward of about 35° N, while the polar-orbiting satellites provide a greater coverage of AOD poleward of 35° N. However, we note several areas across the domain of interest from Asia to North America where the GOES-15 and MTSAT-2 retrieval algorithms can introduce significant uncertainties into the new product.
关键词： trans-Pacific transport,MODIS,VIIRS,near-real time,aerosol optical depth,MTSAT-2,satellite observations,GOES-15
更新于2025-09-10 09:29:36
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[IEEE 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Honolulu, HI, USA (2018.7.18-2018.7.21)] 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Real-Time Retinal Processing for High-Resolution Optogenetic Stimulation Device
摘要： We present in this paper an image processing technique called Circular Distortion and Motion Compensation (CDMC) that can perform real-time retinal processing with geometric compensation for the ring structure arraignment in the retina for bipolar and ganglion cells. The system was running on an embedded platform of Raspberry Pi 3 and managed to achieve a respectable 12 frames per second on a 640×480 resolution live video capture from a webcam. The system emulates biological processes occurring in the retina such as motion estimation and temporal filtering while compensating for the radial shift of ganglion and bipolar cells in human retina. The proposed algorithm is efficient enough to run on mobile hardware with battery powered device in real-time and it is ideal for high resolution optogenetic stimulation devices that targets the retina.
关键词： Retinal processing,Circular interpolation,Optogenetic stimulation,Real-time embedded system
更新于2025-09-10 09:29:36
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[IEEE 2018 International Conference on Indoor Positioning and Indoor Navigation (IPIN) - Nantes, France (2018.9.24-2018.9.27)] 2018 International Conference on Indoor Positioning and Indoor Navigation (IPIN) - Real-Time Localization and Tracking Using Visible Light Communication
摘要： In this paper an optical indoor positioning system is proposed, which utilizes modulated LED lights as anchor points, deployed in known positions. The sensor, deployed on the tracked object (e.g. autonomous vehicle), is an ordinary camera facing upwards. The system is able to estimate the position and orientation of the moving object in real-time, based on the camera’s image stream, containing images of the anchor points. The paper contains comprehensive analysis on the possible error sources and their effect on the positioning accuracy. Real measurement tests show that the accuracy of the system is in the low centimeter range even if the tracked camera moves with a speed of 1 m/s.
关键词： indoor positioning,heuristic data fusion,Visible Light Communication,fisheye camera,real-time tracking
更新于2025-09-09 09:28:46
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Unsupervised classification-based hyperspectral data processing: lossy compression
摘要： The existing lossy compression algorithms play an important role in reducing the cost of storage equipment and bandwidth for hyperspectral (HS) application. However, none of the lossy compression algorithms considers the real-time classification of HS data. In this paper, we present a new lossy compression method for HS data that aims to optimally compress in both spatial and spectral domains and simultaneously maximize classification performance. For this target, Harsanyi–Farrand–Chang (HFC) and k-means++ algorithms are applied to achieve a spectral library and an index matrix for HS image. Spectral angle mapping and Euclidean distance are used to update the spectral library and the index matrix. The experiment results indicate that the proposed method has a good classification performance. The results also reveal that the proposed method works well in real-time classification and compression of HS data with a large volume and achieves a high compression ratio. It is noteworthy to mention that the superiority of our method in compression becomes more apparent as the volume of HS data grows. Consequently, the proposed method has a strong advantage in HS applications that require both compression and classification.
关键词： Real-time classification,Index matrix,Lossy compression,Spectral library,Hyperspectral (HS) image
更新于2025-09-09 09:28:46
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Effect of deposition rate on the growth mechanism of microcrystalline silicon thin films using very high frequency PECVD
摘要： The intrinsic microcrystalline silicon thin films were deposited by very high frequency plasma enhanced chemical vapor deposition (VHF-PECVD). Two series of films with different deposition rate 0.30 nm/s and 1.94 nm/s were prepared. The film surface and gas phase reaction growth processes were monitored with real-time spectroscopic ellipsometry and optical emission spectroscopy. The effect of deposition rate on the microcrystalline silicon thin film growth mechanism has been studied. The microcrystalline silicon surface growth was analyzed with KPZ model. The results show that the growth exponent of β is 0.448 for the films with low deposition rate, and the growth exponent of β is 0.302 for the films with high deposition rate. The growth exponent does not increase with deposition rate, but declines. And the reasons for this phenomenon were explained.
关键词： Real time spectroscopic ellipsometry,Microcrystalline silicon,High rate deposition,Optical emission spectrum,Growth mechanism
更新于2025-09-09 09:28:46