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[IEEE 2018 Digital Image Computing: Techniques and Applications (DICTA) - Canberra, Australia (2018.12.10-2018.12.13)] 2018 Digital Image Computing: Techniques and Applications (DICTA) - Classifier-Free Extraction of Power Line Wires from Point Cloud Data
摘要： This paper proposes a classi?er-free method for extraction of power line wires from aerial point cloud data. It combines the advantages of both grid- and point-based processing of the input data. In addition to the non-ground point cloud data, the input to the proposed method includes the pylon locations, which are automatically extracted by a previous method. The proposed method ?rst counts the number of wires in a span between the two successive pylons using two masks: vertical and horizontal. Then, the initial wire segments are obtained and re?ned iteratively. Finally, the initial segments are extended on both ends and each individual wire points are modelled as a 3D polynomial curve. Experimental results show both the object-based completeness and correctness are 97%, while the point-based completeness and correctness are 99% and 88%, respectively.
关键词： power line,point cloud,extraction,wire,modelling
更新于2025-09-19 17:15:36
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Thermal and illumination effects on a PbI <sub/>2</sub> nanoplate and its transformation to CH <sub/>3</sub> NH <sub/>3</sub> PbI <sub/>3</sub> perovskite
摘要： Movie highlights are composed of video segments that induce a steady increase of the audience’s excitement. Automatic movie highlights’ extraction plays an important role in content analysis, ranking, indexing, and trailer production. To address this challenging problem, previous work suggested a direct mapping from low-level features to high-level perceptual categories. However, they only considered the highlight as intense scenes, like fighting, shooting, and explosions. Many hidden highlights are ignored because their low-level features’ values are too low. Driven by cognitive psychology analysis, combined top-down and bottom-up processing is utilized to derive the proposed two-way excitement model. Under the criteria of global sensitivity and local abnormality, middle-level features are extracted in excitement modeling to bridge the gap between the feature space and the high-level perceptual space. To validate the proposed approach, a group of well-known movies covering several typical types is employed. Quantitative assessment using the determined excitement levels has indicated that the proposed method produces promising results in movie highlights’ extraction, even if the response in the low-level audio-visual feature space is low.
关键词： movie exciting degree,movie highlights’ extraction,affective computing,excitement modeling
更新于2025-09-19 17:15:36
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The confined space electron transfer in phosphotungstate intercalated ZnAl-LDHs enhances its photocatalytic performance for oxidation/extraction desulfurization of model oil in air
摘要： Deep desulfurization of fuels is a hot issue in the environmental protection field in recent years. Phosphotungstate intercalated hydrotalcites (ZnAl-(PW12O40)x-LDHs) with varying amounts of PW12O40^3? were prepared by an exfoliation-reassembly method, and their structures and properties were characterized by diverse techniques. The present process uses ZnAl-(PW12O40)x-LDHs as the catalyst, air as the oxidant, and acetonitrile as the extractant to remove dibenzothiophene (DBT) from model oil under UV irradiation. Results show that ZnAl-(PW12O40)0.07-LDHs has high photocatalytic activity at ambient temperature and pressure. 95.3% desulfurization can be achieved after 3 h UV irradiation at a catalyst dosage of 1 g L?1 and volume ratio of acetonitrile to oil = 1. There was no significant decline in catalyst performance after five catalytic cycles. Mechanism of photocatalytic oxidation desulfurization is revealed using methods, such as ESR, PL, electrochemical tests and active species trapping experiments. The main active species is found to be superoxygen anion free radicals (?O2?) and photogenerated holes (h+). The high photocatalytic activity is mainly attributed to the synergistic effect between subject and object of the photocatalyst with confined space electron transfer, as well as extraction. A new system of photocatalytic oxidation/extraction desulfurization was constructed, and for the first time, LDHs material was applied to photocatalytic desulfurization of oil.
关键词： confined space electron transfer,hydrotalcite,photocatalytic desulfurization,phosphotungstate,oxidation/extraction
更新于2025-09-19 17:15:36
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Cost effective synthesis of p-type Zn-doped MgAgSb by planetary ball-milling with enhanced thermoelectric properties
摘要： A melamine-based porous organic polymer (mPMF) was synthesized as solid phase extraction (SPE) adsorbent for inline SPE-high performance liquid chromatography (HPLC)-ultraviolet detector (UV) analysis of five phytohormones. Melamine contributed to the rich π-electron and N-containing triazine structure for mPMF, which could form π-π interaction and intermolecular hydrogen bond with -COOH containing phytohormones. The synthesized mPMF adsorbent shows extremely high extraction efficiency for five target analytes (>80%) including salicylic acid, indole-3-acetic acid, abscisic acid, 2,4-dichlorophenoxyacetic acid and 1-naphthalene acetic acid. The factors affecting extraction of the target phytohormones were investigated and the optimized experimental conditions were established. The linear range was 0.2–100 μg/L for five target phytohormones. The developed method of mPMF-inline-SPE-HPLC-UV was applied for the analysis of trace target phytohormones in tomato and grape juice samples, and the recovery in the range of 83.1–116% and 87.2–121% was obtained for the spiked tomato and grape juice, respectively. This method has the advantages of high sensitivity and good reproducibility, and it has good application potential for the analysis of phytohormones in fruit samples. Moreover, inline analysis avoided the problems of sample pollution and sample loss, and provided a sample throughput of 5/h.
关键词： Phytohormones,Porous organic polymer,Fruit juice,Inline solid phase extraction,High performance liquid chromatography
更新于2025-09-19 17:15:36
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Automatic segmentation in image stacks based on multi-constraint level-set evolution
摘要： Contour extraction of image stacks is a basic task in medical modeling. The existing level-set methods usually suffer from some problems (e.g. serious errors around sharp features, incorrect split of topology and contour occlusions). This paper proposes a novel method of multi-constraint level-set evolution to avoid above-mentioned problems. Interpolation constraint and deviation constraint are added to evolution process in addition to existing constraints (such as edge points and areas). In order to prevent occlusions, it proposes a method of three-phase level-set evolution. The first phase obtains a rough contour according to selected edge points. The second phase applies an expanding LSE (level-set evolution). Missing edge points in the first phase are added when occlusions probably appear. In the third phase, occlusions are deleted and a refining evolution is implemented. As proved by final experiments, our method can steadily extract contours slice by slice when the shapes of previous contours (contours in the previous slice) are similar to current contours (contours in the current slice). Furthermore, there is no error propagation during the process of contour extraction.
关键词： level-set evolution,multi-constraint,Contour extraction
更新于2025-09-19 17:15:36
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Enhancement of thermographic images of composite laminates for debond detection: An approach based on Gabor filter and watershed
摘要： Spacecraft structures use materials which require high stiffness and low mass. Subjected to high thermal and acoustic loads, their health is of utmost importance. These structures are vulnerable to debonding and delaminations which are identified as defects. Non-destructive way of inspecting these components is very essential to detect the debonding defects. Debond defects are not visible to naked eyes and hence conventional optical cameras will not serve the purpose of automating inspection. For this purpose, we have used thermography. Passing the thermographic images through stages like enhancement, segmentation and feature extraction by using techniques like watershed segmentation, active contours and texture classification through Gabor filter are attempted in this study. Defects are brought out which help in taking corrective steps to avoid failure of the materials during actual life of the spacecraft.
关键词： Noise removal,Feature Extraction,Watershed algorithm,Active Contours,Gabor filter,Thermal Imaging
更新于2025-09-19 17:15:36
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Efficient electrochemical detection and extraction of copper ions using ZnSe-CdSe/SiO2 core-shell nanomaterial
摘要： Development of nanostructured materials has received tremendous attention nowadays due to their unique properties and efficacious in wide range of applications. Herein, we present a facile synthesis of ZnSe-CdSe/SiO2 core-shell nanomaterial for pollutants monitoring and environmental remediation purposes. The utility of ZnSe-CdSe/SiO2 core-shell nanomaterial was explored toward electrochemical detection and adsorptive removal of copper ions from aquatic system. Experimental results reveal that both electrochemical detection and adsorption of Cu(II) using ZnSe-CdSe/SiO2 nanomaterial strongly depends on the solution pH, with an optimum pH of 5. Based on the results, the amperometric sensor based on ZnSe-CdSe/SiO2 core-shell nanomaterial modified electrode exhibited a detection limit of 50 μgL?1. Moreover, ZnSe-CdSe/SiO2 core-shell nanomaterial as adsorbent demonstrated high uptake capacity equals to 126.25 mgg?1. Thus, ZnSe-CdSe/SiO2 core-shell nanomaterial can be employed as promising material for several environmental remediation purposes.
关键词： Core-shell,Adsorption,Copper,ZnSe-CdSe/SiO2,Electrochemical Sensor,Nanomaterial,Extraction
更新于2025-09-19 17:15:36
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Is Low-Level Laser Therapy Effective for Pain Control After the Surgical Removal of Unerupted Third Molars? A Randomized Trial
摘要： One of the main challenges after extraction of unerupted third molars is pain control, and one of the treatments for pain control is low-level laser therapy (LLLT). Thus, this study aimed to assess the effectiveness of LLLT for pain control after extraction of lower third molars. Materials and Methods: This randomized, double-blind, split-mouth study included patients who required bilateral extraction of unerupted lower third molars. Patients received LLLT on 1 side (laser group) but not on the opposite side (control group). On the experimental side, each patient received a laser application at 5 intraoral points for 30 seconds per point. This procedure was simulated on the control side. The pain control response was assessed with a modified pain visual analog scale at the following times: immediately after surgery (T0), after laser application (T1), 24 hours after surgery (T2), 48 hours after surgery (T3), and 72 hours after surgery (T4). Results: Thirty-two patients, 56.25% of whom were women, underwent extraction; the average age was 22.2 years. At the times analyzed, the laser group presented better results than the control group. As for the times, there were differences in pain scores between T0 (8.03 ± 14.87) and T3 (2.66 ± 4.23), as well as T4 (3.36 ± 7.83), in the laser group and differences between T0 (19.76 ± 26.66) and T3 (7.11 ± 10.76), as well as T4 (6.26 ± 13.14), in the control group. Conclusion: LLLT was effective in reducing pain after surgical removal of unerupted third molars. At T3 and T4, pain reduction in relation to T0 was noted in both groups.
关键词： low-level laser therapy,pain control,extraction,randomized trial,third molars
更新于2025-09-19 17:13:59
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[IEEE 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Paris, France (2019.9.1-2019.9.6)] 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - A Gap Waveguide Fed Circular Polarization Antenna in the Millimeter-Wave Range
摘要： Due to its wide applications in practice, face recognition has been an active research topic. With the availability of adequate training samples, many machine learning methods could yield high face recognition accuracy. However, under the circumstance of inadequate training samples, especially the extreme case of having only a single training sample, face recognition becomes challenging. How to deal with con?icting concerns of the small sample size and high dimensionality in one-sample face recognition is critical for its achievable recognition accuracy and feasibility in practice. Being different from the conventional methods for global face recognition based on generalization ability promotion and local face recognition depending on image segmentation, a single-sample face recognition algorithm based on locality preserving projection (LPP) feature transfer is proposed here. First, transfer sources are screened to obtain the selective sample source using the whitened cosine similarity metric. Second, we project the vectors of source faces and target faces into feature subspace by LPP, respectively, and calculate the feature transfer matrix to approximate the mapping relationship on source faces and target faces in subspace. Then, the feature transfer matrix is used on training samples to transfer the original macro characteristics to target macro characteristics. Finally, the nearest neighbor classi?er is used for face recognition. Our results based on popular databases FERET, ORL, and Yale demonstrate the superiority of the proposed LPP feature transfer-based one-sample face recognition algorithm when compared with popular single-sample face recognition algorithms, such as (PC)2A and Block FLDA.
关键词： one-sample,Feature extraction,face recognition,locality preserving projection,transfer learning
更新于2025-09-19 17:13:59
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AlGaN deep-ultraviolet light-emitting diodes grown on SiC substrates
摘要： The disinfection industry would greatly benefit from efficient, robust, high-power deep-ultraviolet light-emitting diodes (UV-C LEDs). However, the performance of UV-C AlGaN LEDs is limited by poor light-extraction efficiency (LEE) and the presence of a large density of threading dislocations. We demonstrate high power AlGaN LEDs grown on SiC with high LEE and low threading dislocation density. We employ a crack-free AlN buffer layer with low threading dislocation density and a technique to fabricate thin-film UV LEDs by removing the SiC substrate, with a highly selective SF6 etch. The LEDs (278 nm) have a turn-on voltage of 4.3 V and a CW power of 8 mW (82 mW/mm2) and external quantum efficiency (EQE) of 1.8% at 95 mA. KOH submicron roughening of AlN surface (nitrogen-polar) and improved p-contact reflectivity are found to be effective in improving the LEE of UV light. We estimate the improved LEE by semi-empirical calculations to be 33% (without encapsulation). This work establishes UV LEDs grown on SiC substrates as a viable architecture to large-area, high-brightness, and high power UV LEDs.
关键词： AlGaN LEDs,UV-C LEDs,light extraction efficiency,disinfection technology,AlN,external quantum efficiency,SiC,substrate removal
更新于2025-09-19 17:13:59