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- 2019
- photobiomodulation
- Brain hemodynamics
- longitudinal data analysis
- functional mixed-effect model
- Optoelectronic Information Science and Engineering
- Texas A&M University
- University of Texas at Arlington
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[IEEE 2018 IEEE 8th International Conference on Consumer Electronics - Berlin - Berlin, Germany (2018.9.2-2018.9.5)] 2018 IEEE 8th International Conference on Consumer Electronics - Berlin (ICCE-Berlin) - Fast Rain Removal Using Rain Map and Temporal Filtering for Consumer Imaging Applications
摘要： This paper presents the severe weather image enhancement method using for consumer imaging systems. The proposed method performs the rain removal based on a rain map, which estimated by the difference among the adjacent frames. In the video frames, since the rain streaks can be regarded as the object moving in a constant direction, we can analyze the position of the rain streaks using the difference between the previous and next frames. In addition, we refine the rain map using the saturation channel in HSV color space and low-pass filtering. Experimental results show that the proposed method can provide better restored image at fast processing time compared with existing methods.
关键词： Deraining,Rain removal,Rain property
更新于2025-09-23 15:23:52
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Evaluation of Atmospheric Detrimental Effects on Free Space Optical Communication System for Delhi Weather
摘要： Free Space Optical (FSO) communication systems are gaining popularity due to its tremendous speed, advanced capacity, cost effectiveness, secure and easy to deploy wireless networks. This technology has proven an effective choice for last mile applications and hard to reach areas where deployment of optical fibre links is not feasible. But FSO link is highly weather dependent and as signal passes through the atmospheric channel, the main impairments are the atmospheric turbulence, which induce fading and deteriorate the system performance. Delhi has a great potential for FSO communication because of its clear skies. Since there is no analysis for weather condition found in Delhi, this work provides analysis of typical Delhi weather condition ranging from heavy to light rain, fog and clear sky. The performance of FSO link is analysed in terms of attenuation and link length margin under different weather condition. The results are concluded to identify which atmospheric condition influences more on FSO link performance.
关键词： rain attenuation,atmospheric attenuation,free space optical communication,absorption,scattering,visibility,rainfall rate,Delhi weather condition,fog attenuation,link margin
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE International Ultrasonics Symposium (IUS) - Glasgow, United Kingdom (2019.10.6-2019.10.9)] 2019 IEEE International Ultrasonics Symposium (IUS) - Simultaneous dictionary learning and reconstruction from subsampled data in photoacoustic microscopy
摘要： The Global Precipitation Measurement (GPM) Core Observatory will carry a Dual-frequency Precipitation Radar (DPR) consisting of a Ku-band precipitation radar (KuPR) and a Ka-band precipitation radar (KaPR). In this study, “at-launch” codes of DPR precipitation algorithms, which will be used in GPM ground systems at launch, were evaluated using synthetic data based upon the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) data. Results from the codes (Version 4.20131010) of the KuPR-only, KaPR-only, and DPR algorithms were compared with “true values” calculated based upon drop size distributions assumed in the synthetic data and standard results from the TRMM algorithms at an altitude of 2 km over the ocean. The results indicate that the total precipitation amounts during April 2011 from the KuPR and DPR algorithms are similar to the true values, whereas the estimates from the KaPR data are underestimated. Moreover, the DPR estimates yielded smaller precipitation rates for rates less than about 10 mm/h and greater precipitation rates above 10 mm/h. Underestimation of the KaPR estimates was analyzed in terms of measured radar re?ectivity ( ) of the KaPR at an altitude of 2 km. The underestimation of the KaPR data was most pronounced during strong precipitation events of (high attenuation cases) over heavy precipitation areas in the Tropics, whereas the underestimation was less pronounced when the (moderate attenuation cases). The results suggest that the underestimation is caused by a problem in the attenuation correction method, which was veri?ed by the improved codes.
关键词： simulation,spaceborne radar,rain,Global Precipitation Measurement (GPM),snow,Tropical Rainfall Measuring Mission (TRMM),Algorithms,attenuation
更新于2025-09-19 17:13:59
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Generation of soliton rain in a passive mode-locked Tm-doped fiber laser at 2???μm
摘要： In this paper, the experimental investigation and theoretical analysis on the soliton rain generated in the Tm-doped ?ber laser have been carried out. On the basis of nonlinear polarization rotation technology, the fundamental and harmonic soliton rain pulses were obtained, the in?uence of net negative dispersion cavity length on the output performances of soliton rain pulse were studied, and the spectral sideband characteristics of soliton rain were numerically analyzed. By comparing the spectra of continuous wave mode-locking and soliton rain states, it can be found that the quasi-periodic modulation exists for the spectral sideband of soliton rain resulted from the complex interaction between the dispersive wave and the soliton wave. The interaction is one of the major factors for the formation of soliton rain. The research results are helpful for the better understanding of the soliton rain dynamics and mechanism in passive mode-locked ?ber lasers.
关键词： Fiber laser,Passively mode-locked,Soliton rain,Tm-doped
更新于2025-09-19 17:13:59
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AIP Conference Proceedings [AIP Publishing TECHNOLOGIES AND MATERIALS FOR RENEWABLE ENERGY, ENVIRONMENT AND SUSTAINABILITY: TMREES19Gr - Athens, Greece (4–6 September 2019)] TECHNOLOGIES AND MATERIALS FOR RENEWABLE ENERGY, ENVIRONMENT AND SUSTAINABILITY: TMREES19Gr - Rain formation by free electron laser pulse system FELPS
摘要： At present, several problems and challenges have arisen as a result of human population growth and technological development, including global warming, water shortages and drought, especially in arid zones characterized by high temperatures.The low rainfall leads to increased drought and desertification, which has a negative impact on human life. In this study, a new laser technique was proposed to create rain in the atmosphere. Artificial rain can be formed by the proper energy of the laser pulse that stimulates a series of chemical and physical reactions in the clouds to obtain the appropriate rain drops.This technique is based on the use of a free electron beam with suitable energy and adaptable to the weather conditions by changing the wavelength and intensity of the laser beam and the duration of the pulse, ensuring that water droplets of sufficient size to fall.
关键词： atmospheric reactions,laser pulse,FELPS,artificial rain,free electron laser
更新于2025-09-16 10:30:52
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[IEEE 2018 IEEE International Conference on Electro/Information Technology (EIT) - Rochester, MI (2018.5.3-2018.5.5)] 2018 IEEE International Conference on Electro/Information Technology (EIT) - Framework for Simulating and Rem,/Oving Rain in Stereo-Image Videos
摘要： We present an implementation of a rain simulation and rain removal framework, which is based on video streams captured with a stereo camera system. This framework can be used to study the effect of rain on vision-based systems in the automotive domain, including obstacle detection, vehicles tracking and traffic sign recognition. We also present testing techniques, to verify the performance of rain simulation/ removal systems, and quantify the closeness of de-rained image to the original rain-free image.
关键词： Simulated rain,rain density,rain streaks,stereo-vision,de-raining,focal length
更新于2025-09-10 09:29:36
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Modeling of effective path-length based on rain cell statistics for total attenuation prediction in satellite link
摘要： ITU-R recommends a global rain-attenuation prediction model for satellite link, but it lacks a physical meaning because it is an empirical model and the effective path-length model is frequency dependent. In this paper, a global effective path-length model, which can be used for total attenuation prediction in satellite link, is proposed. The proposed model is a physical model based on rain-cell concept. The test for the proposed model was performed against the data in the ITU-R SG3 DB, using the procedures in the recommendation ITU-R P. 311 and the Fascicle. The test results show that the prediction error of the proposed model is less than the existing ITU-R model. In addition, the proposed model is a physical model and simple compared to the current ITU-R model.
关键词： Total attenuation,Effective path length,Rain cell,Satellite link
更新于2025-09-10 09:29:36
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Stone/Coating Interaction and Durability of Si-Based Photocatalytic Nanocomposites Applied to Porous Lithotypes
摘要： The use of hybrid nanocoatings for the protection of natural stones has received increasing attention over the last years. However, the interaction of these materials with stones and, in particular, its modification resulting from the blending of nanoparticles and matrices, are yet little explored. In this work, the interaction of two nanocomposite coatings (based on alkylalkoxysilane matrices and TiO2 nanoparticles in water and 2-propanol) with two different porous stones is examined in detail by comparing their absorption behaviour and protection performance with those of the respective TiO2-free matrices. It is shown that the protective effectiveness of both matrices is not negatively affected by the presence of TiO2, as the desired water barrier effect is retained, while a significant photocatalytic activity is achieved. The addition of titania leads to a partial aggregation of the water-based matrix and accordingly reduces the product penetration into stones. On the positive side, a chemical interaction between titania and this matrix is observed, probably resulting in a greater stability of nanoparticles inside the protective coating. Moreover, although an effect of TiO2 on the chemical stability of matrices is observed upon UV light exposure, the protective performance of coatings is substantially maintained after ageing, while the interaction between matrices and nanoparticles results in a good retention of the latter upon in-lab simulated rain wash-out.
关键词： UV ageing,stone protection,water-repellency,photo-oxidative degradation,durability,artificial rain,photocatalysis,TiO2 nanoparticles,alkylalkoxysilane
更新于2025-09-09 09:28:46
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Improved rain-rate and drop-size retrievals from airborne and spaceborne Doppler radar
摘要： Satellite radar remote-sensing of rain is important for quantifying of the global hydrological cycle, atmospheric energy budget, and many microphysical cloud and precipitation processes; however, radar estimates of rain rate are sensitive to assumptions about the rain drop size distribution. The upcoming EarthCARE satellite will feature a 94 GHz Doppler radar alongside lidar and radiometer instruments, presenting opportunities for enhanced global retrievals of the rain drop size distribution. In this paper we demonstrate the capability to retrieve both rain rate and a parameter of the rain drop size distribution from an airborne 94 GHz Doppler radar using CAPTIVATE, the variational retrieval algorithm developed for EarthCARE radar–lidar synergy. For a range of rain regimes observed during the Tropical Composition, Cloud and Climate Coupling (TC4) field campaign in the eastern Pacific in 2007, we explore the contributions of Doppler velocity and path-integrated attenuation (PIA) to the retrievals, and evaluate the retrievals against independent measurements from a second, less attenuated, Doppler radar aboard the same aircraft. Retrieved drop number concentration varied over five orders of magnitude between light rain from melting ice, and warm rain from liquid clouds. Doppler velocity can be used to estimate rain rate over land, and retrievals of rain rate and drop number concentration are possible in profiles of light rain over land; in moderate warm rain, drop number concentration can be retrieved without Doppler velocity. These results suggest that EarthCARE rain retrievals facilitated by Doppler radar will make substantial improvements to the global understanding of the interaction of clouds and precipitation.
关键词： CAPTIVATE,satellite radar remote-sensing,EarthCARE,rain rate,path-integrated attenuation,Doppler radar,retrieval algorithm,drop size distribution
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE International Conference on Intelligent Transportation Systems (ITSC) - Maui, HI, USA (2018.11.4-2018.11.7)] 2018 21st International Conference on Intelligent Transportation Systems (ITSC) - Automotive LiDAR performance verification in fog and rain
摘要： This article focuses on testing and investigating further development needs for LiDARs in self-driving cars in adverse weather. The article compares two different LiDARs (Ibeo Lux and Velodyne PUCK), which both use the 905 nm wavelengths, which are used in more than 95 % of currently available LiDARs. The performance was tested and estimated in stabilized fog conditions at Cerema fog chamber facilities. This provides a good basis for repeating the same validation procedure multiple times and ensuring the right development decisions. However, performance of the LiDARs suffers when the weather conditions become adverse and visibility range decreases. A 50 % reduction in target detection performance was observed over the exhaustive tests. Therefore, changing to higher wavelengths (1550 nm) was considered using redesigned “pre-prototype LiDAR”. The preliminary results indicate that there is no reason to not use 1550 nm wavelength, which due to eye safety regulations gives an opportunity to use 20 times more power compared to the traditional 905 nm. In order to clarify the expected benefits, additional feasibility studies are still needed.
关键词： self-driving cars,LiDAR,sensor performance,1550 nm,905 nm,adverse weather,rain,fog
更新于2025-09-04 15:30:14