Improved Image Processing Techniques Research Articles

Characterizing Liquid Water Distribution in Polymer Electrolyte Fuel Cells Using Operando 2D and 3D X-Ray Imaging

The potential to reduce the cost of Polymer Electrolyte Fuel Cells (PEFCs) through high power density operation is limited by the attending water management challenges at such operating conditions [1]. Addressing PEFC water management requires detailed understanding of liquid water distribution characteristics of an operating fuel cell, to refine the design of membrane electrode assemblies (MEAs) for improved performance.Recent advances in X-ray operando imaging [2, 3] and custom hardware development [4], have enabled the visualization of liquid water in an operating PEFC, through the analysis of water phase segmented 3-dimensional (3D) images [2, 3] and 2-dimensional (2D) radiographs [5]. 2D image datasets may be acquired in a shorter time than 3D tomographic datasets but only provide grayscale information averaged through the thickness of the sample. 3D image datasets obtained from a reconstruction of many angular radiographs yield a 3D representation of the sample in addition to the grayscale information but take a long collection time. However, time dependent liquid water distribution characteristics such as channel water breakthrough, observable in the 2D image datasets, tend to be elusive to 3D imaging methods. Although efforts have been made to reduce the image acquisition time for 3D X-ray imaging by using Synchrotron sources and improved image processing techniques [2], these efforts tend to compromise image quality and are restricted to a brief temporal snapshot of liquid water distribution. Also, the brightness of the Synchrotron sources necessitates short exposure duration tests due to the likelihood of cell degradation caused by the sample’s exposure to radiation [4]. Given the unique capabilities of 2D and 3D imaging modes, we therefore focus on combining information accessible in both modes to further the understanding of PEFC liquid water distribution.In this work, an improved understanding of liquid water distribution in the PEFC is presented by integrating operando 2D and 3D image datasets acquired under the same cell operating conditions and using laboratory scale X-ray computed tomography (XCT) equipment which was interfaced with fuel cell testing and diagnostic tools. Analysis of 3D image datasets is extended beyond binary information to include the grayscale value (GSV) of liquid water to reveal a change in the through-plane values. These results, when combined with observed 2D liquid water breakthrough characteristics suggest that the change in GSV is indicative of the differences in the intermittency of liquid water presence in the different regions of the GDL; see Figure 1. These results therefore present a more complete interpretation of PEFC operando liquid water distribution, highlighting distinct characteristics from the microporous (MPL) region to the GDL-land interface. Unique findings and insight obtained using this methodology will be discussed. Acknowledgments Funding for this research was provided by the Natural Sciences and Engineering Research Council of Canada, Ballard Power Systems, Canada Foundation for Innovation, British Columbia Knowledge Development Fund, Western Economic Diversification Canada, and Canada Research Chairs. References Jiao and X. Li, Progress in energy and combustion Science, vol. 37, no. 3, pp. 221–291, 2011.Xu, S. Nagashima, H. P. Nguyen, K. Kishita, F. Marone, F. N. Büchi, and J. Eller, Journal of Power Sources, vol. 490, p. 229492, 2021.Nagai, J. Eller, T. Hatanaka, S. Yamaguchi, S. Kato, A. Kato, F. Marone, H. Xu, and F. N. Büchi, Journal of Power Sources, vol. 435, p. 226809, 2019.T. White, F. P. Orfino, M. El Hannach, O. Luo, M. Dutta, A. P. Young, and E. Kjeang, Journal of The Electrochemical Society, vol. 163, no. 13, pp. F1337–F1343, 2016.R. Banerjee, N. Ge, J. Lee, M. G. George, S. Chevalier, H. Liu, P. Shrestha, D. Muirhead, and A. Bazylak, Journal of The Electrochemical Society, vol. 164, no. 2, p. F154, 2017. Figure 1

Improved Image Processing Techniques for User Immersion Problem Alleviation in Virtual Reality Environments

The latest advertisements on the advancements of the virtual reality has paved way for diverse studies, in manifold fields that can benefit by utilizing the technologies of the virtual reality, not excluding the design, gaming and the simulated understanding. Yet whenever a virtual reality device conveys information in form of images with the assistance of the display that is positioned closer to the user’s eyes it faces problems like minimizing the speed of the process and degradation in the quality of images ending up in huge variations across the virtual realism and the realism causing user immersion problems. So to mitigate the immersion problems of the user because of the low quality of image and the minimization of processing speed in the virtual reality environments the paper puts forth an improved image processing technique to improvise the sharpness of the images in order to enhance quality of the images and heighten the processing speed.

Improved image processing techniques for optic disc segmentation in retinal fundus images

Glaucoma is one of the leading causes of blindness in the world and is projected to affect over 79.6 million people globally. Recently, automated computer aided systems are used in disease detection and proven to be highly useful in assisting experts in the early diagnosis. Hence, automated optic disc segmentation through the intelligent system is very much helpful for the early detection of Glaucoma. This paper presents an improved image processing algorithm for retinal fundus images using region based Pixel density calculation method for optic disc localization and improved Circular Hough Transform with Hough Peak value selection and Red channel Superpixel segmentation for Optic disc segmentation. Optic disc segmentation has been applied on eight publically available databases, HRF, DRISHTI-GS1, DRIONS-DB, DRIVE, ONHSD, CHASE-DB1, INSPIRE and MESSIDOR and the accuracy of 99.73%, 99.31%, 99.37%, 99.38%, 99.64%, 99.20%, 99.31%, 99.72% and also specificity of 99.90%, 99.43%, 99.60%, 99.52%, 99.82%, 99.43%, 99.84%, 99.89% were obtained with less than 2 s computation time for an image. The result of the proposed technique shows that the system is highly competitive with the state-of-the-art and achieves better accuracy with fast execution time.

Flow of quasi-spherical nanoparticles in liquid composite molding processes. Part I: Influence of particle size and fiber distance distribution

This paper studies the flow and filtration of two quasi-spherical NPs (silica and boehmite) during liquid composite molding (LCM) processes. The nanosuspensions are prepared differently by “top-down” and “bottom-up” approaches, and the particle size is analyzed before and after injection process. In parallel, the fiber distance distribution is systematically characterized using improved image processing techniques and algorithms. It is found that nanosuspensions that are prepared by “top-down” approach may show a bimodal particle distribution, and that the filtration of quasi-spherical NPs is closely related to the bimodal distribution characteristics of the particle size and the dual-scale characteristic of the preform. Furthermore, a threshold fiber volume fraction (Vf) of 55% is identified, at which the investigated preform shows a critical phase transition from dual-scale to single micro-scale porous structure. It is shown that above the threshold Vf even a small fraction of coarse particles can strongly hinder the impregnation process.

Medical Diagnosis of Upper Urinary Calculi Based on Image Filtering in Ureteroscopic Lithotripsy

Objective: Based on improved image processing techniques, we investigate the therapeutic effect and safety of a flexible ureteroscope applied in treatment of upper urinary calculi with and without preoperative ureteral stent, and analyzed their outcome based on CT and ultrasound medical imaging technology, as well as other clinical data. Methods: These identified patients were randomly divided into two groups, 89 patients suffering from upper urinary calculi in Group A were treated with flexible ureteroscopy lithotripsy and Holmium laser, without preoperative ureteral stent. On the other hand, another 114 patients in Group B received preoperative ureteral stent. In terms of measurement indicators, the total operation time, hospitalization time, hospital costs, success rate of operation, clearance rate of stone, occurrence rate of complications, and the probability of a second operation were recorded, respectively. In order to verify the effect of the operation, we performed Computed Tomography (CT), Nuclear Magnetic Resonance Imaging (MRI), Ultrasound Examination on the patient before and after the operation, and processed the image by downhill filtering algorithm and adaptive median filtering to ensure the validity and accuracy of the experiment. Results: By analyzing other clinical data such as medical images, it is known when making comparisons between two groups, there were no significant difference in terms of stone size, stone site, and success rate of operation (97.8%, 87/89 for group A; 100%, 114/144 for group B). In further, the operation time of group A was longer than that of group B (65.46 ± 10.17 min vs. 59.58 ± 9.25 min, P < 0 05), and the hospitalization time in group A was much shorter (6.53 ± 0.89 d vs. 10.16 ± 1.50 d, P < 0.01). The clearance rate of stone at 3-day post-surgery in group A was much lower than that of group B (36%, 32/89 vs. 51.7%, 59/114, P < 0.05). In addition, the clearance rate of stone at 1-month post-surgery (84.3%, 75/89 in group A vs. 85.1%, 97/114 in group B), and the occurrence rate of complications (21.3%, 19/89 in group A vs. 20.1%, 23/114 in group B) showed no significantly difference (P > 0.05). Besides, the probabilities of a second operation in group A and B were 14.6% (19/89) and 20.1% (23/114), respectively. And no significantly difference could be drawn according to statistical analysis. Conclusion: The application of flexible ureteroscope applied in treatment of upper urinary calculi without preoperative ureteral stent was economical, safe and effective.

무인기 기반의 교량 균열 탐지를 위한 타당성 연구

This paper deals with the study of the detection and quantification of cracks in bridge structures using image data obtained by using unmanned aerial vehicle (UAV). In general, an UAV is influenced by fly environment such as a gust of wind and self-excitation during bridge inspection. Therefore, a feasibility study is required in order to verify the performance in dynamical environment. In this study, a 2D motion jig was fabricated to simulate the dynamical environment. And a steel and two concrete crack specimens were prepared. To detect crack of the specimens, improved image processing techniques (IPTs) are proposed. It is aimed to correct the image distortion due to the vibration that can occur in the appearance of the bridge using the drone. Performances of the technique were evaluated through lab-test. Finally, improved IPTs are applied to the detected regions to quantify cracks at 100 micrometers. The non-contact detection technology of bridge damage proposed in this study can be applied to the actual bridge inspection field and it is expected that the economic and technical efficiency will be high.

Improved proton CT imaging using a bismuth germanium oxide scintillator

Range uncertainty is among the most formidable challenges associated with the treatment planning of proton therapy. Proton imaging, which includes proton radiography and proton computed tomography (pCT), is a useful verification tool. We have developed a pCT detection system that uses a thick bismuth germanium oxide (BGO) scintillator and a CCD camera. The current method is based on a previous detection system that used a plastic scintillator, and implements improved image processing techniques. In the new system, the scintillation light intensity is integrated along the proton beam path by the BGO scintillator, and acquired as a two-dimensional distribution with the CCD camera. The range of a penetrating proton is derived from the integrated light intensity using a light-to-range conversion table, and a pCT image can be reconstructed. The proton range in the BGO scintillator is shorter than in the plastic scintillator, so errors due to extended proton ranges can be reduced. To demonstrate the feasibility of the pCT system, an experiment was performed using a 70 MeV proton beam created by the AVF930 cyclotron at the National Institute of Radiological Sciences. The accuracy of the light-to-range conversion table, which is susceptible to errors due to its spatial dependence, was investigated, and the errors in the acquired pixel values were less than 0.5 mm. Images of various materials were acquired, and the pixel-value errors were within 3.1%, which represents an improvement over previous results. We also obtained a pCT image of an edible chicken piece, the first of its kind for a biological material, and internal structures approximately one millimeter in size were clearly observed. This pCT imaging system is fast and simple, and based on these findings, we anticipate that we can acquire 200 MeV pCT images using the BGO scintillator system.

Chronic Wound Image Analysis by Particle Swarm Optimization Technique for Tele-Wound Network

This paper presents an outline of methods that have been proposed for the analysis of chronic wound images. This paper indicates the details of four different ulcerous cases, provides good treatment policy, enhances quality of patient’s life, improves evidence based clinical outcomes and suggests best possible issues. This paper investigates efficient filtering techniques for chronic wound image pre-processing under Tele-wound network. The aim of this work is to accurately access the healing status of chronic wound with improved image processing techniques by proper filtering. Efficient filtering techniques help to reduce the noise for wound images. The simulation results are presented by comparing different parameters. Performance parameters are peak signal to noise ratio (PSNR), mean square error (MSE), signal to noise ratio and mean absolute error. Results shows adaptive Median filtering provides better performances with respect to high PSNR and reduced MSE between original and filtered image. This work proposes the Particle Swarm Optimization (PSO) method for segmentation of wound areas via suitable color space selection. The PSO algorithm in Db channel provided good accuracy (98.93%) for chronic wound segmentation. Here proposed Linier discriminant analysis classifier provides 98% overall tissue prediction accuracy. The aim is to develop telemedicine framework for wound diagnosis by improving good interaction between health experts, patients, and tele-medical agents who belongs to rural/urban areas that are involved in the provision of care to resolve the delayed treatment.

Towards an integrative structural biology approach: combining Cryo-TEM, X-ray crystallography, and NMR.

Cryo-transmission electron microscopy (Cryo-TEM) and particularly single particle analysis is rapidly becoming the premier method for determining the three-dimensional structure of protein complexes, and viruses. In the last several years there have been dramatic technological improvements in Cryo-TEM, such as advancements in automation and use of improved detectors, as well as improved image processing techniques. While Cryo-TEM was once thought of as a low resolution structural technique, the method is currently capable of generating nearly atomic resolution structures on a routine basis. Moreover, the combination of Cryo-TEM and other methods such as X-ray crystallography, nuclear magnetic resonance spectroscopy, and molecular dynamics modeling are allowing researchers to address scientific questions previously thought intractable. Future technological developments are widely believed to further enhance the method and it is not inconceivable that Cryo-TEM could become as routine as X-ray crystallography for protein structure determination.

Remote Sensing and Geographic Information System for Appraisal of Salt‐Affected Soils in India

Quantification of the nature, extent, and spatial distribution of salt-affected soils (SAS) for India and the world is essential for planning and implementing reclamation programs in a timely and cost-effective manner for sustained crop production. The national extent of SAS for India over the last four decades was assessed by conventional and remote sensing approaches using diverse methodologies and class definitions and ranged from 6.0 to 26.1 million hectares (Mha) and 1.2 to 10.1 Mha, respectively. In 1966, an area of 6 Mha under SAS was first reported using the former approach. Three national estimates, obtained using remote sensing, were reconciled using a geographic information system, resulting in an acceptable extent of 6.73 Mha. Moderately and severely salt-encrusted lands having large contiguous area have been correctly mapped, but slightly salt-encrusted land having smaller affected areas within croplands has not been accurately mapped. Recent satellite sensors (e.g., Resourcesat-1, Cartosat-2, IKONOS-II, and RISAT-2), along with improved image processing techniques integrated with terrain and other spatial data using a geographic information system, are enabling mapping at large scale. Significant variations in salt encrustation at the surface caused by soil moisture, waterlogging conditions, salt-tolerant crops, and dynamics of subsurface salts present constraints in appraisal, delineation, and mapping efforts. The article provides an overview of development, identification, characterization, and delineation of SAS, past and current national scenarios of SAS using conventional and remote sensing approaches, reconciliation of national estimates, issues of SAS mapping, and future scope.

Spectral studies at the Vatican: Laboratory analysis and telescopic observations

A review is presented of studies of spectra at the Vatican Observatory in the past century and a half. These began with the pioneer research of Angelo Secchi at the Collegio Romano in grouping stars according to their surface temperatures into four spectral types. Work continued under Gatterer, Junkes and Salpeter in the Astrophysical Laboratory at Castel Gandolfo, where the chief work was the production of the Vatican Spectral Atlases of elements and molecules. Now (1989) stellar spectroscopy occupies the Vatican astronomers who use the largest telescopes with improved image processing techniques to classify spectra of faint stars and galaxies.

Higher resolution satellite remote sensing and the impact on image mapping

Recent advances in spatial, spectral, and temporal resolution of civil land remote sensing satellite data are presenting new opportunities for image mapping applications. The U.S. Geological Survey's experimental satellite image mapping program is evolving toward larger scale image map products with increased information content as a result of improved image processing techniques and increased resolution. Thematic mapper data are being used to produce experimental image maps at 1:100,000 scale that meet established U.S. and European map accuracy standards. Availability of high quality, cloud-free, 30-meter ground resolution multispectral data from the Landsat thematic mapper sensor, along with 10-meter ground resolution panchromatic and 20-meter ground resolution multispectral data from the recently launched French SPOT satellite, present new cartographic and image processing challenges. The need to fully exploit these higher resolution data increases the complexity of processing the images into large-scale image maps. The removal of radiometric artifacts and noise prior to geometric correction can be accomplished by using a variety of image processing filters and transforms. Sensor modeling and image restoration techniques allow maximum retention of spatial and radiometric information. An optimum combination of spectral information and spatial resolution can be obtained by merging different sensor types. These processing techniques are discussed and examples are presented.