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oe1(光电查) - 科学论文

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  • A Method of Interstory Drift Monitoring Using a Smartphone and a Laser Device

    摘要： Interstory drift is an important engineering parameter in building design and building structural health monitoring. However, many problems exist in current interstory drift monitoring methods. The traditional method is imprecise—double numerical integration of acceleration data—and other direct monitoring methods need professional equipment. This paper proposes a method to solve these problems by monitoring the interstory drift with a smartphone and a laser device. In this method, a laser device is installed on the ceiling while a smartphone is ?xed on a steel projection plate on the ?oor. Compared with a reference sensor, the method designed in this study shows that a smartphone is competent in monitoring the interstory drift. This method utilizes a smartphone application (APP) named D-Viewer to implement monitoring and data storage just in one place, which is also inexpensive. The results showed that this method has an average percent error of 3.37%, with a standard deviation of 2.67%. With the popularization of the smartphone, this method is promising in acquiring large amounts of data, which will be signi?cant for building assessment after an earthquake.

    关键词： structural health monitoring,laser device,interstory drift,smartphone,seismic monitoring

    更新于2025-09-23 15:19:57

  • [IEEE 2018 IEEE Biomedical Circuits and Systems Conference (BioCAS) - Cleveland, OH, USA (2018.10.17-2018.10.19)] 2018 IEEE Biomedical Circuits and Systems Conference (BioCAS) - Block-Sparse Compressive Sensing for High-Fidelity Recording of Photoplethysmogram

    摘要： This paper presents a novel compressive sensing (CS) framework for photoplethysmogram (PPG) recording. Exploiting the concept of block sparsity in CS, the proposed framework trains a block-sparsifying dictionary for the PPG signal using the block K-SVD (BK-SVD) algorithm. Next, the block sparse Bayesian learning (BSBL) algorithm is employed to utilize the block-sparsity information and recover the PPG signal from its compressively sampled counterpart. Using different PPG datasets prerecorded from the fingertip of a healthy human volunteer under normal and post-exercise conditions, our results demonstrate that the proposed CS framework based on BK-SVD + BSBL can achieve signal-to-noise and distortion ratio (SNDR) values of >10dB for compression ratios as high as 10, outperforming the previous approaches for compressive sensing of PPG that do not utilize the block-sparsity information.

    关键词： photoplethysmogram,wearable health monitoring,Block sparsity,dictionary training,compressive sensing

    更新于2025-09-19 17:15:36

  • Remote sensing equivalent water thickness of grass treated with different fertiliser regimes using resample HyspIRI and EnMAP data

    摘要： The aim of this study was to test the spectral settings of the forthcoming EnMAP and HyspIRI hyperspectral imagers in estimating equivalent water thickness of native grass grown under different management practices, using two regression ensembles (partial least squares regression (PLSR) and sparse partial least squares regression (SPLSR)). Results showed that the HyspIRI spectral settings better characterised Equivalent water thickness (EWT) of grass grown under different fertiliser regimes in relation to the EnMAP spectral settings. Specifically, t-test analysis indicated there were significant differences (α = 0.05) between the (pooled) relative root mean square errors derived using the HyspIRI spectral settings when compared to those exhibited by EnMAP. When all data was combined, HyspIRI spectral data settings exhibited relatively higher accuracy in estimating grass EWT with a RMSE of 3.039 g cm?2 (RRMSE = 31.7%) and an R-square of 0.59 when compared to EnMAP which exhibited a RMSE of 3.216 g cm?2 (RRMSE = 33.6%) and an R-square of 0.54. The near infrared and shortwave infrared bands were selected as the most optimally variables in estimating grass water content across different grassland management practices using the SPLSR. These findings are critical for monitoring grasslands condition at landscape scale. Overall this information is critical for determining and understanding their moisture retention capacity across different land management practices and in light of climate variability and change.

    关键词： Grassland management practices,Spectral settings,Water content,Grassland health

    更新于2025-09-19 17:15:36

  • Dynamic and quasi-static signal separation method for bridges under moving loads based on long-gauge FBG strain monitoring

    摘要： Structural health monitoring is an important means of obtaining the state information of bridges, and the extracted quasi-static strain signal can reflect the stress state of bridges directly. However, the strain signals acquired during the operation stage of bridges are dynamic, and the strain gauges used in the health monitoring system are short (no more than 10 cm), which means they are easily affected by small damage at the installation parts of bridges and thereby the monitoring signal abnormalities occur. A type of externally affixed long-gauge fiber strain gauge is used to monitor the health of bridges, and the dynamic and quasi-static signal separation method for long-gauge strain sensors is studied under different vehicle loads; at the same time, the dynamic monitoring performance of the long-gauge sensor is investigated in this paper. The quasi-static strain signal extracted from the dynamic macro-strain signal can be used to directly monitor the stress status of the bridge. The results show that the method proposed in this paper is feasible for extracting the quasi-static macro-strain from a dynamic long-gauge strain signal.

    关键词： signal processing,bridge engineering,empirical mode decomposition method,macro-strain,Bridge health monitoring

    更新于2025-09-19 17:15:36

  • Identifying Asphalt Pavement Distress Using UAV LiDAR Point Cloud Data and Random Forest Classification

    摘要： Asphalt pavement ages and incurs various distresses due to natural and human factors. Thus, it is crucial to rapidly and accurately extract different types of pavement distress to effectively monitor road health status. In this study, we explored the feasibility of pavement distress identification using low-altitude unmanned aerial vehicle light detection and ranging (UAV LiDAR) and random forest classification (RFC) for a section of an asphalt road that is located in the suburb of Shihezi City in Xinjiang Province of China. After a spectral and spatial feature analysis of pavement distress, a total of 48 multidimensional and multiscale features were extracted based on the strength of the point cloud elevations and reflection intensities. Subsequently, we extracted the pavement distresses from the multifeature dataset by utilizing the RFC method. The overall accuracy of the distress identification was 92.3%, and the kappa coefficient was 0.902. When compared with the maximum likelihood classification (MLC) and support vector machine (SVM), the RFC had a higher accuracy, which confirms its robustness and applicability to multisample and high-dimensional data classification. Furthermore, the method achieved an overall accuracy of 95.86% with a validation dataset. This result indicates the validity and stability of our method, which highway maintenance agencies can use to evaluate road health conditions and implement maintenance.

    关键词： UAV,random forest classification,pavement health conditions,LiDAR,asphalt pavement distresses,multiscale features

    更新于2025-09-19 17:15:36

  • A Turbulence-Oriented Approach to Retrieve Various Atmospheric Parameters Using Advanced Lidar Data Processing Techniques

    摘要： The article is aimed at presenting a semi-empirical model coded and computed in the programming language Python, which utilizes data gathered with a standard biaxial elastic lidar platform in order to calculate the altitude profiles of the structure coefficients of the atmospheric refraction index C2N(z) and other associated turbulence parameters. Additionally, the model can be used to calculate the PBL (Planetary Boundary Layer) height, and other parameters typically employed in the field of astronomy. Solving the Fernard–Klett inversion by correlating sun-photometer data obtained through our AERONET site with lidar data, it can yield the atmospheric extinction and backscatter profiles α(z) and β(z), and thus obtain the atmospheric optical depth. Finally, several theoretical notions of interest that utilize the solved parameters are presented, such as approximated relations between C2N(z) and the atmospheric temperature profile T(z), and between the scintillation of backscattered lidar signal and the average wind speed profile U(z). These obtained profiles and parameters also have several environmental applications that are connected directly and indirectly to human health and well-being, ranging from understanding the transport of aerosols in the atmosphere and minimizing the errors in measuring it, to predicting extreme, and potentially-damaging, meteorological events.

    关键词： RCS,temperature profile,structure coefficients,environment,human health,atmospheric extinction,atmospheric backscatter,wind speed profile,lidar,turbulence

    更新于2025-09-19 17:15:36

  • Smartphone-based analytical biosensors

    摘要： The traditional analytical biosensor instruments are relatively bulky, expensive, and not easy to handle, thus their applications are largely limited in resource-limited settings. The recent development of microfluidic lab-on-a-chip (LOC) technology has provided a possible solution to miniaturize the conventional biosensing system, yet other accessory devices to detect, readout, analyze, transfer, and display results are still required. With the rapid development, mass production, and pervasive distribution of smartphones in recent years, they have provided people with portable, cost-effective, and easy-to-operate platforms to build analytical biosensors for point-of-care (POC) applications and mobile health. Based on the common analytical methods, this paper reviews the recent development of four types of smartphone-based analytical biosensory systems at the POC, i.e., smartphone-based microscopic imaging, colorimetric, electrochemical, and electrochemiluminescence biosensor. The different bio-sensing strategies and analytical performance together with future perspectives are discussed.

    关键词： point-of-care,smartphone-based biosensors,analytical methods,mobile health,microfluidic

    更新于2025-09-19 17:15:36

  • RetoNet: a deep learning architecture for automated retinal ailment detection

    摘要： Researchers are trying to tap the immense potential of big data to revolutionize all aspects of societal activity and to assist in having well informed decisions. Healthcare being one such field where proper analytics of available big medical data can lead to early detection and treatment of many ailments. Machine learning played a significant role in the design of automated diagnostic systems and today we have deep learning models in this arena which are outperforming human expertise in terms of predictive accuracy. This paper proposes RetoNet, a convolutional neural network architecture, which is trained and optimized to detect retinal ailment from fundus images with pronounced accuracy and its performance is also proven to be superior to a transfer learning based model developed for the same. Deep learning based e-diagnostic system can be an accurate, cost effective and convenient solution for the shortage of expertise on demand in the healthcare field.

    关键词： Convolutional neural network,E-health,Retinal disease detection,ANN,Deep learning

    更新于2025-09-19 17:15:36

  • Experiencia de atención en red entre Hospital del Salvador y tres unidades de Atención Primaria Oftalmológica: Un modelo de salud pública para mejorar la atención oftalmológica

    摘要： Background: Primary care units of ophtalmology (UAPO) were incorporated in 2003 into the healthcare system of the Ministry of Health, in response to the high demand for hospital care. Three of these primary care units were incorporated to provide a network care with the ophthalmology service of a tertiary care hospital. Aim: To report the public health impact of networking. Material and Methods: A descriptive-prospective study was carried out analyzing all the healthcare attentions carried out between June and August 2016. An epidemiological characterization of the sample was made. We recorded: clinical diagnoses, decisions, resolution of the clinical problem at the primary care or referral to the hospital. Results: A total of 2,096 ophthalmologic attentions were carried out in the three UAPOs during the study period. The main diseases attended were disorders of refraction, cataracts, glaucoma and diabetic retinopathy. The resolution index was 84% of attentions. Only 16% of attentions required referral and consisted mainly of cataracts (covered by a special health care system), diabetic retinopathy, capsulotomies, iridotomies, uveitis, pterygium and lacrimal duct obstruction. Conclusions: This model of care allowed an efficient management of the high demand for hospital referral. This is expressed in the high-resolution index and low derivation, resulting in a decrease in waiting lists at the tertiary level. This system should be implemented by other tertiary centers of our country.

    关键词： Ophthalmology,Primary Health Care,Tertiary Healthcare

    更新于2025-09-19 17:15:36

  • [IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - A New Approach to Indoor Characterization of PV Module Energy Yield Parameters

    摘要： The ballistocardiogram (BCG), a signal describing the reaction forces of the body to cardiac ejection of blood, has recently gained interest in the research community as a potential tool for monitoring the mechanical aspects of cardiovascular health for patients at home and during normal activities of daily living. An important limitation in the field of BCG research is that while the BCG signal measures the forces of the body, the information desired (and understood) by clinicians and caregivers, regarding mechanical health of the cardiovascular system, is typically expressed as blood pressure or flow. This paper aims to explore, using system identification tools, the mathematical relationship between the BCG signal and the better-understood impedance cardiography (ICG) and arterial blood pressure (ABP) waveforms, with a series of human subject studies designed to asynchronously modulate cardiac output and blood pressure and with different magnitudes. With this approach, we demonstrate for 19 healthy subjects that the BCG waveform more closely maps to the ICG (flow) waveform as compared with the finger-cuff-based ABP (pressure) waveform, and that the BCG can provide a more accurate estimate of stroke volume (r = 0.73, p < 0.05) as compared with pulse pressure changes (r = 0.26). We also examined, as a feasibility study, for one subject, the ability to calibrate the BCG measurement tool with an ICG measurement on the first day, and then track changes in stroke volume on subsequent days. Accordingly, we conclude that the BCG is a signal more closely related to blood flow than pressures, and that a key health parameter for titrating care—stroke volume—can potentially be accurately measured with BCG signals at home using unobtrusive and inexpensive hardware, such as a modified weighing scale, as compared with the state-of-the-art ICG and ABP devices, which are expensive and obtrusive for use at home.

    关键词： Ballistocardiogram,hemodynamics,cardiovascular health,home monitoring

    更新于2025-09-19 17:13:59