48 results on '"Junhao, Zhao"'
Search Results
2. SemanticFlow: Semantic Segmentation of Sequential LiDAR Point Clouds From Sparse Frame Annotations
- Author
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Junhao Zhao, Weijie Huang, Hai Wu, Chenglu Wen, Bo Yang, Yulan Guo, and Cheng Wang
- Subjects
General Earth and Planetary Sciences ,Electrical and Electronic Engineering - Published
- 2023
3. Forecasting loss given default for peer-to-peer loans via heterogeneous stacking ensemble approach
- Author
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Lingyun He, Xiaoli Yang, Yinguo Li, Junhao Zhao, and Yufei Xia
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Information asymmetry ,Loan ,Computer science ,Collateral ,Benchmark (computing) ,Econometrics ,Capital requirement ,Business and International Management ,Loss given default ,Credit risk ,Parametric statistics - Abstract
Peer-to-peer (P2P) lending is an emerging field in FinTech and is an alternative source of personal loans. However, P2P lending faces severe credit risk due to high information asymmetry and insufficient collateral. We develop a novel heterogeneous stacking ensemble (HSE) approach by using two real-world datasets to improve the loss given default (LGD) forecasting in the P2P lending domain. Some special data in P2P lending and macroeconomic variables are employed as supplementary data sources to further enhance the model performance. Our proposal is compared with several popular models, including parametric and non-parametric ones, in terms of predictive accuracy and capital requirement. Our finding reveals that special data in P2P lending (e.g., number of investors and loan description) and macroeconomic variables are powerful predictors of LGD in P2P lending. The proposed HSE model outperforms the benchmark models in most cases and significantly achieves optimal average ranks across all the evaluation metrics. The results remain robust under several validations.
- Published
- 2021
4. Sentiment analysis method based on CNN and attention mechanism
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Lisha Yao, Junhao Zhao, Kang Su, and Qingtong Shao
- Published
- 2022
5. The Response of Geomagnetic Daily Variation and Ionospheric Currents to the Annular Solar Eclipse on 21 June 2020
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Xiaocan Liu, Junjie Chen, Peng Han, Jiuhou Lei, Tong Dang, Fuqing Huang, Huaran Chen, Liguo Jiao, Xinxin Ma, Jiyao Tu, Yu Lei, and Junhao Zhao
- Subjects
Geophysics ,Space and Planetary Science - Published
- 2022
6. Consequent Construction of C–C and C–N Bonds via Palladium-Catalyzed Dual C–H Activation: Synthesis of Benzo[c]cinnoline Derivatives
- Author
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Kongzhen Hu, Hongsheng Li, Pengju Feng, Songjian Yi, and Junhao Zhao
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inorganic chemicals ,Annulation ,010405 organic chemistry ,Ligand ,Aryl ,Organic Chemistry ,chemistry.chemical_element ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,0104 chemical sciences ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Pyrazolones ,Physical and Theoretical Chemistry ,Benzo(c)cinnoline ,Cinnoline ,Palladium - Abstract
A highly efficient palladium-catalyzed cascade annulation of pyrazolones and aryl iodides to access various benzo[c]cinnoline derivatives has been achieved at 80 °C. A pyridine-type ligand could im...
- Published
- 2021
7. Electro-oxidative C–H amination of heteroarenes with aniline derivatives via radical–radical cross coupling
- Author
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Guojian Ma, Shiyu Hu, Xichao Peng, Junhao Zhao, Pengju Feng, Yan Wu, and Zhixiong Ruan
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Indole test ,Coupling (electronics) ,chemistry.chemical_compound ,Aniline ,Radical ion ,Chemistry ,Environmental Chemistry ,Oxidative phosphorylation ,Pollution ,Combinatorial chemistry ,Amination - Abstract
The selective synthesis of C-2/C-3 aminated five-membered heteroarenes incorporated various functionalities with aniline derivatives in a sustainable way remains an unmet challenge. This protocol presents a practical protocol for the C–H amination of heteroarenes via an electro-oxidative cross coupling process. This electrosynthetic approach enables a facile access to a wide variety of synthetically useful hetero-arene derivatives, tolerates a wide range of functional groups, and is amenable to gram scale synthesis. In addition, a preliminary mechanistic study reveals that a radical cross coupling process between the N-centered radical and indole radical cation may be involved for this amination reaction.
- Published
- 2021
8. Cyclic-di-AMP Phosphodiesterase Elicits Protective Immune Responses Against
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Yanzhi, Lu, Huanhuan, Ning, Jian, Kang, Guangchun, Bai, Lei, Zhou, Yali, Kang, Zhengfeng, Wu, Maolin, Tian, Junhao, Zhao, Yueyun, Ma, and Yinlan, Bai
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Antigens, Bacterial ,Mice ,Bacterial Proteins ,Phosphoric Diester Hydrolases ,Cyclic AMP ,Animals ,Tuberculosis ,Mycobacterium tuberculosis ,CD8-Positive T-Lymphocytes ,Tuberculosis Vaccines ,Adenosine Monophosphate ,Immunity, Innate - Abstract
Many antigens from
- Published
- 2022
9. Wogonin reduces cardiomyocyte apoptosis from mitochondrial release of cytochrome c to improve doxorubicin‑induced cardiotoxicity
- Author
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Yunjie Wei, Junhao Zhao, Jian Xiong, Jingjing Chai, Xi Yang, Junfeng Wang, Jiajuan Chen, and Jing Wang
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Cancer Research ,Immunology and Microbiology (miscellaneous) ,General Medicine - Published
- 2022
10. Automatically modeling piecewise planar furniture shapes from unorganized point cloud
- Author
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Guozhu Liu, Junhao Zhao, Jian Xu, Chen Zong, Shiqing Xin, Shuangmin Chen, and Luming Cao
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Computer science ,General Engineering ,Point cloud ,020207 software engineering ,02 engineering and technology ,Computer Graphics and Computer-Aided Design ,Regularization (mathematics) ,Human-Computer Interaction ,Orthogonality ,Convex optimization ,0202 electrical engineering, electronic engineering, information engineering ,Piecewise ,020201 artificial intelligence & image processing ,Point (geometry) ,Representation (mathematics) ,Cluster analysis ,Algorithm - Abstract
Piecewise planar 3D objects are very common in digital furniture manufacturing. In this paper, we propose a novel method for automatic reconstruction of 3D objects with planar facets from unorganized point clouds. We formulate this problem into a point clustering problem where the key difficulty lies in consolidating co-planar points into a cluster. In order to achieve this purpose, the first step is to triangulate the input point cloud into a mesh (may have over connectivity) that is a super-set of the underlying manifold mesh surface. Then the hundreds of thousands of normal vectors of triangles, after being mapped onto a Gauss sphere, are capable of reporting reliable facing directions of the faces of the final 3D model. After grouping the points based on co-planarity, we fit each cluster with a planar facet and then assemble them into a piecewise planarization representation of the whole model. We further introduce an additional regularization term to meet the orthogonality requirement on a particular occasion, and then transform this problem into a purely convex optimization problem. Our method is efficient and requires just a few parameters. Extensive experimental results show that it is able to handle point clouds with various levels of noise and yield a desirable piecewise planar 3D model with a clean and compact representation.
- Published
- 2020
11. Simple Aggregation‐Induced Emission‐Based Multifunctional Fluorescent Dots for Cancer Therapy In Vitro
- Author
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Pengju Feng, Fang Yang, Hongxing Liu, Tianfeng Chen, Junhao Zhao, Wei Huang, and Xueran Lin
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Nanoparticle ,Apoptosis ,010402 general chemistry ,Endocytosis ,01 natural sciences ,Biochemistry ,Cell Line, Tumor ,Neoplasms ,Lysosome ,Quantum Dots ,Thiadiazoles ,medicine ,Humans ,Cytotoxicity ,Fluorescent Dyes ,Aniline Compounds ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,General Chemistry ,Fluorescence ,In vitro ,0104 chemical sciences ,medicine.anatomical_structure ,Benzaldehydes ,Biophysics ,Reactive Oxygen Species ,Intracellular - Abstract
Multifunctional nanoparticles were simply synthesized by mixing a TICT+AIE featured molecule (TPAPP-CHO) with PBS solution. The fluorescent (FL) dots entered the cells via energy-related endocytosis and were located in lysosome emitting green FL. This indicated that the nanoparticles were dissociated in the lysosome. Moreover, the synthesized nanoparticles (NPs) demonstrate potent cytotoxicity against human U87 glioblastoma cells by inducing cell apoptosis via triggering intracellular ROS overproduction.
- Published
- 2019
12. An integrated collaborative decision-making method for optimizing energy consumption of sail-assisted ships towards low-carbon shipping
- Author
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Kai Wang, Xin Guo, Junhao Zhao, Ranqi Ma, Lianzhong Huang, Feng Tian, Siyi Dong, Peng Zhang, Chunlei Liu, and Zhuang Wang
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Environmental Engineering ,Ocean Engineering - Published
- 2022
13. Satellite Remote Sensing Identification of Discolored Standing Trees for Pine Wilt Disease Based on Semi-Supervised Deep Learning
- Author
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Jiahao Wang, Junhao Zhao, Hong Sun, Xiao Lu, Jixia Huang, Shaohua Wang, and Guofei Fang
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General Earth and Planetary Sciences ,pine wilt disease (PWD) ,semi-supervised ,semantic segmentation ,satellite remote sensing ,accurate monitoring - Abstract
Pine wilt disease (PWD) is the most dangerous biohazard of pine species and poses a serious threat to forest resources. Coupling satellite remote sensing technology and deep learning technology for the accurate monitoring of PWD is an important tool for the efficient prevention and control of PWD. We used Gaofen-2 remote sensing images to construct a dataset of discolored standing tree samples of PWD and selected three semantic segmentation models—DeepLabv3+, HRNet, and DANet—for training and to compare their performance. To build a GAN-based semi-supervised semantic segmentation model for semi-supervised learning training, the best model was chosen as the generator of generative adversarial networks (GANs). The model was then optimized for structural adjustment and hyperparameter adjustment. Aimed at the characteristics of Gaofen-2 images and discolored standing trees with PWD, this paper adopts three strategies—swelling prediction, raster vectorization, and forest floor mask extraction—to optimize the image identification process and results and conducts an application demonstration study in Nanping city, Fujian Province. The results show that among the three semantic segmentation models, HRNet was the optimal conventional semantic segmentation model for identifying discolored standing trees of PWD based on Gaofen-2 images and that its MIoU value was 68.36%. Additionally, the GAN-based semi-supervised semantic segmentation model GAN_HRNet_Semi improved the MIoU value by 3.10%, and its recognition segmentation accuracy was better than the traditional semantic segmentation model. The recall rate of PWD discolored standing tree monitoring in the demonstration area reached 80.09%. The combination of semi-supervised semantic segmentation technology and high-resolution satellite remote sensing technology provides new technical methods for the accurate wide-scale monitoring, prevention, and control of PWD.
- Published
- 2022
14. A study on overlapping effect of melt pools in powder bed fusion based on a novel prediction method
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Junhao Zhao, Binbin Wang, Tong Liu, Liangshun Luo, Yanan Wang, Xiaonan Zheng, Liang Wang, Yanqing Su, Jingjie Guo, Hengzhi Fu, and Dayong Chen
- Subjects
Biomedical Engineering ,General Materials Science ,Engineering (miscellaneous) ,Industrial and Manufacturing Engineering - Published
- 2022
15. Laser-based powder bed fusion of pre-alloyed oxide dispersion strengthened steel containing yttrium
- Author
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Yanan Wang, Binbin Wang, Liangshun Luo, Binqiang Li, Tong Liu, Junhao Zhao, Beibei Xu, Liang Wang, Yanqing Su, Jingjie Guo, and Hengzhi Fu
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Biomedical Engineering ,General Materials Science ,Engineering (miscellaneous) ,Industrial and Manufacturing Engineering - Published
- 2022
16. Wogonin reduces cardiomyocyte apoptosis from mitochondrial release of cytochrome
- Author
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Yunjie, Wei, Junhao, Zhao, Jian, Xiong, Jingjing, Chai, Xi, Yang, Junfeng, Wang, Jiajuan, Chen, and Jing, Wang
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cytochrome c ,polycyclic compounds ,cardiotoxicity ,anti-apoptotic ,Articles ,wogonin ,doxorubicin - Abstract
Doxorubicin (DOX) has powerful anticancer properties, but its clinical application is affected by its serious cardiotoxicity. Wogonin (WG) has been shown to have marked cardiovascular protection potential. However, it is not known whether this potential can protect the heart from DOX damage. The aim of the present study was to investigate whether WG could ameliorate the cardiotoxicity of DOX. DOX and WG were used to establish a model of cardiac damage. Echocardiography, brain natriuretic peptide, creatine kinase MB and cardiac troponin T were used to detect the degree of cardiac damage. The levels of superoxide dismutase, malondialdehyde, glutathione and catalase in serum were measured to observed oxidative stress state. The mRNA levels of cyclophilin D, voltage-dependent anion-selective channel 1 and adenine nucleotide transporter 1 were detected by reverse transcription-quantitative PCR. Western blotting was used to detect the expression of cytochrome c in mitochondria and cytoplasm and cleaved-caspase-9 and pro/cleaved-caspase-3 in cytoplasm in cardiac tissue and primary cardiomyocytes to verify the related signaling pathways. DOX rats showed a series of cardiac damage. However, these damages were alleviated following WG treatment. Further studies showed that WG antagonized DOX cardiotoxicity through inhibiting the release of cytochrome c. WG protected rat heart from DOX damage. The mechanism may be closely related to inhibiting the release of cytochrome c from mitochondria and reducing cardiomyocyte apoptosis caused by caspase activation.
- Published
- 2021
17. Electro-Oxidative C-N Bond Formation through Azolation of Indole Derivatives: An Access to 3-Substituent-2-(Azol-1-yl)indoles
- Author
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Naifu Zhou, Chengbo Sun, Junhao Zhao, Pengju Feng, Yuqin Lai, and Zhixiong Ruan
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Indole test ,Indoles ,Molecular Structure ,Chemistry ,Bioactive molecules ,Danazol ,Organic Chemistry ,Substituent ,Oxidative phosphorylation ,Bond formation ,Electrochemistry ,Combinatorial chemistry ,chemistry.chemical_compound ,Oxidative Stress ,Surface modification - Abstract
A practical protocol to synthesize 3-substituent-2-(azol-1-yl)indole derivatives has been developed via an electrochemical oxidative cross coupling process under mild conditions. This electro-oxidative C-N bond formation strategy tolerates a range of functional groups and is amenable to gram scale synthesis. Moreover, this method was applied to the late-stage functionalization of bioactive molecules.
- Published
- 2021
18. Reducing oxidative stress may be important for treating pirarubicin-induced cardiotoxicity with schisandrin B
- Author
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Rui Feng, Li Wen, Junhao Zhao, Peng Pu, and Heng Tang
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Cancer Research ,Cardiotoxicity ,Oncogene ,business.industry ,Pirarubicin ,cardiotoxicity ,Cancer ,General Medicine ,Articles ,Cell cycle ,medicine.disease ,medicine.disease_cause ,Molecular medicine ,Immunology and Microbiology (miscellaneous) ,Apoptosis ,schisandrin B ,medicine ,Cancer research ,oxidative stress ,business ,Oxidative stress ,medicine.drug ,pirarubicin - Abstract
The cardiotoxicity of pirarubicin (THP) seriously affects its clinical application, which cannot be ignored. The antioxidant effect of schisandrin B (SchB) has been extensively reported in the context of dietotherapy. However, whether this antioxidant effect can protect the heart from THP damage remains unknown. The aim of the present study was to investigate whether the antioxidant effect of SchB can antagonize the cardiotoxicity of THP. Changes in electrocardiogram (ECG), echocardiography and serum lactate dehydrogenase, brain natriuretic peptide, creatine kinase MB and cardiac troponin T levels were used to detect the degree of cardiac damage. The levels of superoxide dismutase (SOD), malondialdehyde, catalase and total antioxidant capacity in the serum and heart were measured to observe the oxidative stress state of rats. Primary cardiomyocytes were cultured, and cell viability and reactive oxygen species (ROS) production were detected. Western blotting was used to detect the expression levels of SOD2, NOX2, pro/cleaved-caspase3 and Bcl-2/Bax in heart tissue and primary cardiomyocytes to verify the related signaling pathways. THP-treated rats showed a range of cardiac damage, including an abnormal ECG, echocardiography and myocardial enzymes. In the cellular experiments, cell viability decreased and ROS increased. However, this damage was alleviated after SchB treatment. Further studies demonstrated that SchB antagonized THP cardiotoxicity via its antioxidant effect. In conclusion, SchB protects the heart from THP damage in rats, and the mechanism may be closely associated with its antioxidant effect.
- Published
- 2021
19. Research on Bank Personal Credit Evaluation Based on Decision Tree Model
- Author
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JunHao Zhao
- Published
- 2021
20. GemNN: Gating-enhanced Multi-task Neural Networks with Feature Interaction Learning for CTR Prediction
- Author
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Ping Li, Junhao Zhao, Xinyang Qi, Jingyuan Zhang, Xingxuan Zhou, and Hongliang Fei
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Artificial neural network ,business.industry ,Computer science ,Multi-task learning ,Machine learning ,computer.software_genre ,Online advertising ,Task (computing) ,Search advertising ,Feature (machine learning) ,Upstream (networking) ,Artificial intelligence ,Information flow (information theory) ,business ,computer - Abstract
Deep neural network (DNN) models have been widely used for click-through rate (CTR) prediction in online advertising. The training framework typically consists of embedding layers and multi-layer perceptions (MLP). At Baidu Search Ads (a.k.a. Phoenix Nest), the new generation of CTR training platform has become PaddleBox, a GPU-based parameter server system. In this paper, we present Baidu's recently updated CTR training framework, called Gating-enhanced Multi-task Neural Networks (GemNN). In particular, we develop a neural network based multi-task learning model to predict CTR in a coarse-to-fine manner, which gradually reduces ad candidates and allows parameter sharing from upstream tasks to downstream tasks to improve the training efficiency. Also, we introduce a gating mechanism between embedding layers and MLP to learn feature interactions and control the information flow fed to MLP layers. We have launched our solution in Baidu PaddleBox platform and observed considerable improvements in both offline and online evaluations. It is now part of the current production~system.
- Published
- 2021
21. Phase identification with VMD and HT combined method for an active seismic source experiment
- Author
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Xinxin Ma, Zhan Lin, Liguo Jiao, Xiaocan Liu, Jiyao Tu, Yu Lei, and Junhao Zhao
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Applied Mathematics ,Electrical and Electronic Engineering ,Condensed Matter Physics ,Instrumentation - Published
- 2022
22. Moving Object Detection Based on Weighted Kernel Norm and Saliency Constrained RPCA
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Junhao Zhao, Zheng Jiang, Bin Liu, and Ling Zhang
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History ,Computer Science Applications ,Education - Abstract
Focusing on the issue that the accuracy of object detection is reduced when the foreground target moves slowly and there is interference in the background, a moving object detection method based on weighted kernel norm and saliency constraint RPCA is proposed. In the new method, the weighted kernel norm is used to restore a relatively clean background, which is helpful to separate the slow moving target from the background. The l 1 norm is used to constrain the sparsity of moving objects, and the Frobenius norm is used to detect noise, and a saliency constraint is introduced to detect slow-moving objects. Experiments show that this method can effectively deal with the problems of slow foreground motion and background interference. Compared with the suboptimal algorithm, the average measured value F of the proposed algorithm is improved by 15%.
- Published
- 2022
23. Study of in situ formed quasicrystals in Al-Mn based alloys fabricated by SLM
- Author
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Junhao Zhao, Binbin Wang, Tong Liu, Liangshun Luo, Yanan Wang, Xiaonan Zheng, Liang Wang, Yanqing Su, Jingjie Guo, Hengzhi Fu, and Dayong Chen
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Mechanics of Materials ,Mechanical Engineering ,Materials Chemistry ,Metals and Alloys - Published
- 2022
24. Research on the bouncing-ball based triboelectric nanogenerator for self-powered vibration frequency monitoring
- Author
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Peng Zhang, Minyi Xu, Junhao Zhao, Fangyang Dong, Xusheng Zuo, Shunqi Li, Peiting Sun, Zou Yongjiu, Yuewen Zhang, and Taili Du
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Vibration ,Materials science ,business.industry ,Limit (music) ,Electrical engineering ,Nanogenerator ,business ,Signal ,Bouncing ball dynamics ,Triboelectric effect ,Power (physics) ,Voltage - Abstract
Traditional vibration sensor of ship machinery using cable for power supply cannot meet the requirements of a large number of distributed sensors of the intelligent ship. A bouncing-ball based triboelectric nanogenerator (BB-TENG) to be used as a self-powered vibration frequency monitoring sensor is proposed. In the sensing test, the vibration frequency of 15 ∼ 50 Hz under different amplitudes can be measured accurately. The frequency calculation of the voltage signal can accurately reflect external vibration frequency, while the change of short-circuit current has linear relationship with the frequency, and the correlation coefficient is about 0.99. In addition, electrical signal test results and photos taken by high-speed cameras show that the limit of the available detection frequency of BB-TENG increases with the increase of amplitude and support height. The electrical output of BB-TENG under different working conditions are tested, which provides the basis for selecting suitable BB-TENG according to different vibration characteristics.
- Published
- 2021
25. Multi-scale Guided Image and Video Fusion: A Fast and Efficient Approach
- Author
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Junhao Zhao, Gang Xiao, Ravindra Dhuli, Durga Prasad Bavirisetti, and Gang Liu
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Structure (mathematical logic) ,0209 industrial biotechnology ,Fusion ,Pixel ,Property (programming) ,business.industry ,Computer science ,Applied Mathematics ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,02 engineering and technology ,Composite image filter ,Image (mathematics) ,020901 industrial engineering & automation ,Signal Processing ,Decomposition (computer science) ,Computer vision ,Artificial intelligence ,Scale (map) ,business - Abstract
In this paper, we propose a general purpose, simple and fast fusion algorithm based on guided image filter. The proposed method can well combine useful source image information into the fused image supported by multi-scale image decomposition, structure transferring property, visual saliency detection, and weight map construction. Multi-scale image decomposition is appropriate to represent and manipulate image features at various scales. Structure transferring property enabled by our algorithm can induce structures of one source image into the other. A new visual saliency detection based on guided image filter introduced in this paper is able to extract significant regions from visually different images of the same scene. The choice of weight maps helped to integrate the complementary information pixel by pixel at each scale. Experimental outcomes of the proposed method are compared and analyzed with traditional and recent guided image filter-based fusion algorithms in terms of visual quality, fusion metrics and run time. In addition, to enhance fusion results further we made an effort to find a suitable image and video enhancement algorithm. The fusion performance analysis clearly indicates that the proposed method is very promising along with less run time.
- Published
- 2019
26. Power Line Detection for Aircraft Safety Based on Image Processing Techniques: Advances and Recommendations
- Author
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Xingchen Zhang, Junhao Zhao, Ping Ye, Gang Xiao, and Ke Gong
- Subjects
Image fusion ,business.industry ,Computer science ,Deep learning ,Feature extraction ,Aerospace Engineering ,Image processing ,Sensor fusion ,Machine learning ,computer.software_genre ,Constant false alarm rate ,Multimodal learning ,Space and Planetary Science ,Artificial intelligence ,Electrical and Electronic Engineering ,business ,Transfer of learning ,computer ,Hardware_LOGICDESIGN - Abstract
In this paper, an extensive survey on PLD methods for low-altitude aircraft safety based on image processing is presented. First, primary features of power lines are introduced. Then, main studies on PLD are summarized, including PLD approaches based on tradition image processing methods and machine learning. Besides, a few latest research works, such as PLD based on deep learning and infrared images, are discussed. By discussing and comparing current methods, we have proposed future development directions of PLD, with the aim of providing a starting point for researchers in PLD. Specifically, image fusion and multimodal sensor fusion should be able to provide better detection performance and lower false alarm rate by exploiting complementary information from different sensors. In addition, AI will be an important technique in PLD, with the help of transfer learning to utilize limited training data and of multimodal learning to deal with different kinds of information.
- Published
- 2019
27. One-Pot Protocol To Synthesize 2-Aminophenols from Anilines via Palladium-Catalyzed C–H Acetoxylation
- Author
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Guojian Ma, Yifeng Huang, Pengju Feng, Junhao Zhao, and Ling Lin
- Subjects
010405 organic chemistry ,Chemistry ,Organic Chemistry ,chemistry.chemical_element ,010402 general chemistry ,01 natural sciences ,Combinatorial chemistry ,0104 chemical sciences ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,Functional group ,Physical and Theoretical Chemistry ,Palladium - Abstract
This paper describes a facile one-pot protocol to synthesize 2-aminophenol derivatives via a palladium-catalyzed C–H acetoxylation strategy with 5-nitropyrimidine as a directing group (DG), which can be easily preinstalled and readily removed under mild condition after the coupling. In addition, the transformation is operationally simple, has high functional group tolerance, and is amenable to gram-scale. Moreover, several examples were shown that introduction/removal of 5-nitropyrimidine and the C–H oxylation sequence could be integrated in one pot.
- Published
- 2019
28. A High-Performance Flag-Type Triboelectric Nanogenerator for Scavenging Wind Energy toward Self-Powered IoTs
- Author
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Yongjiu Zou, Minzheng Sun, Fei Yan, Taili Du, Ziyue Xi, Fangming Li, Chuanqing Zhu, Hao Wang, Junhao Zhao, Peiting Sun, and Minyi Xu
- Subjects
triboelectric nanogenerators ,wind energy ,distributed sensors ,Internet of Things ,General Materials Science - Abstract
Pervasive and continuous energy solutions are highly desired in the era of the Internet of Things for powering wide-range distributed devices/sensors. Wind energy has been widely regarded as an ideal energy source for distributed devices/sensors due to the advantages of being sustainable and renewable. Herein, we propose a high-performance flag-type triboelectric nanogenerator (HF-TENG) to efficiently harvest widely distributed and highly available wind energy. The HF-TENG is composed of one piece of polytetrafluoroethylene (PTFE) membrane and two carbon-coated polyethylene terephthalate (PET) membranes with their edges sealed up. Two ingenious internal-structure designs significantly improve the output performance. One is to place the supporting sponge strips between the PTFE and the carbon electrodes, and the other is to divide the PTFE into multiple pieces to obtain a multi-degree of freedom. Both methods can improve the degree of contact and separation between the two triboelectric materials while working. When the pair number of supporting sponge strips is two and the degree of freedom is five, the maximum voltage and current of HF-TENG can reach 78 V and 7.5 μA, respectively, which are both four times that of the untreated flag-type TENG. Additionally, the HF-TENG was demonstrated to power the LEDs, capacitors, and temperature sensors. The reported HF-TENG significantly promotes the utilization of the ambient wind energy and sheds some light on providing a pervasive and sustainable energy solution to the distributed devices/sensors in the era of the Internet of Things.
- Published
- 2022
29. Simplicity Driven Edge Refinement and Color Reconstruction in Image Vectorization
- Author
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Wenping Wang, Junhao Zhao, Shiqing Xin, Changhe Tu, Yuanfeng Zhou, Zheng Zhang, and Shuangmin Chen
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Hessian matrix ,Computer science ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Iterative reconstruction ,computer.file_format ,Vector graphics ,symbols.namesake ,Triangle mesh ,Curve fitting ,Piecewise ,symbols ,Image tracing ,Raster graphics ,Algorithm ,computer ,ComputingMethodologies_COMPUTERGRAPHICS - Abstract
Gestalt psychology indicates that simplicity is central to image vectorization, i.e., observers tend to perceive jagged raster edges as piecewise smooth curves and color changes as being either gradual (along edges) or abrupt (across edges). In this paper, we give a pair of simplicity-driven formulations to respectively cope with the two challenges. In detail, we formulate the underlying as-rigid-as-possible edges as the axes of symmetry of the edge saliency map, while reconstructing the color field by enforcing the fidelity and the smoothness at the same time (except on the detected boundaries). We finally convert a rasterized image into gradient-aware vector graphics whose base domain is a high-quality triangle mesh. On the one hand, the rigidity of the boundary curves is naturally achieved based on the assumption of simplicity, instead of by an empirically-grounded curve fitting operation; on the other hand, the color of near-boundary regions is inferred by Hessian energy (an extrapolation-like technique). Our vectorization method is able to yield more visually realistic results than existing approaches and is useful in flexible recoloring, shape editing, and hierarchical level-of-detail (HLOD) image representation.
- Published
- 2021
30. Optimization of RDMA-Based HDFS Data Distribution Mechanism
- Author
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Binbin Liu, Cong Dong, Xiao Zhang, and Junhao Zhao
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File system ,Hardware_MEMORYSTRUCTURES ,Remote direct memory access ,computer.internet_protocol ,Computer science ,InfiniBand ,computer.software_genre ,law.invention ,Internet protocol suite ,law ,Internet Protocol ,Operating system ,Latency (engineering) ,Distributed File System ,computer - Abstract
Hadoop Distributed File System (short for HDFS) is a high availability file system designed to run on commodity hardware. It uses multiple replicas to ensure high reliability, and many data are transmitted between storage nodes. The performance of data transmission has a great impact on the latency of writing operations. Remote Direct Memory Access (short for RDMA) is a protocol with low latency and high through which is running on the Infiniband network. When HDFS runs on the Infiniband network, the default protocol IPoIB can not take advantage of the high-speed network. The latency of the writing process is similar to a TCP/IP network. In this paper, we present a new RDMA-based HDFS writing mechanism. It enables DataNodes to read data parallelly from the Client through RDMA. And by using RDMA primitive, the transmission latency is slower than the original TCP/IP protocol. The experiments show that our approach reduces the latency of the writing process by 10.11%–40.81% compared with the original HDFS.
- Published
- 2021
31. A fluoride ion-mediated continuous etching–redeposition strategy to synthesize Si nanocomposites with appropriate SiO2 coating layers for Li-ion batteries
- Author
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Weixin Zhang, Zeheng Yang, Xiaoming Fan, and Junhao Zhao
- Subjects
Materials science ,chemistry.chemical_element ,02 engineering and technology ,engineering.material ,010402 general chemistry ,01 natural sciences ,Catalysis ,chemistry.chemical_compound ,Coating ,Etching (microfabrication) ,Materials Chemistry ,Nanocomposite ,Metals and Alloys ,General Chemistry ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Amorphous solid ,Anode ,Surface coating ,Chemical engineering ,chemistry ,Ceramics and Composites ,engineering ,Lithium ,0210 nano-technology ,Fluoride - Abstract
Silicon nanocomposites with surface coating have been promising candidates for high-performance anodes in Li-ion batteries. Here we report a simple yet effective way to synthesize Si@SiO2 nanocomposites with amorphous SiO2 coating through a fluoride ion-mediated continuous etching–redeposition process. The Si@SiO2 nanocomposite anode exhibits significantly improved lithium storage properties, with a reversible capacity of 1356 mA h g−1 at 2.1 A g−1 for 300 cycles.
- Published
- 2018
32. Adverse Effects of Inactivated Foot-and-Mouth Disease Vaccine—Possible Causes Analysis and Countermeasures
- Author
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Haixue Zheng, Junhao Zhao, Xiangtao Liu, Bingzhou Lu, Huanan Liu, and Keshan Zhang
- Subjects
Foot-and-mouth disease ,business.industry ,030231 tropical medicine ,Symptomatic treatment ,Disease ,medicine.disease ,03 medical and health sciences ,0302 clinical medicine ,Immunization ,Environmental health ,Inactivated vaccine ,Medicine ,Livestock ,030212 general & internal medicine ,Viral disease ,business ,Adverse effect - Abstract
Foot-and-mouth disease (FMD) is an infectious and sometimes fatal viral disease that affects cloven-hoofed animals, and Chinese government adopts compulsory immunization measures for FMD. The adverse effects of FMD vaccine to pigs, cattle and goats have been reported increasingly frequent during the spring and autumn seasons when large numbers of farm livestock are vaccinated. The financial losses caused by vaccine adverse effects have been a serious concern for both farmers and primary prevention personnel. There are various causative factors reported to involve into adverse effect of FMD vaccine, including the inappropriate vaccine production, transportation and storage, livestock poor tolerance, and unqualified vaccinating manipulations. Symptomatic treatment and early drug prevention have a certain effect on the adverse effects. To analyze causes and propose countermeasures, in the current study possible reasons during the production and processing procedures of inactivated FMD vaccine were reviewed and corresponding countermeasures were recommended. The review may provide references for better use of vaccine to prevent FMD.
- Published
- 2018
33. Selective laser melting Al-3.4Mg-0.5Mn-0.8Sc-0.4Zr alloys: From melting pool to the microstructure and mechanical properties
- Author
-
Luo Lei, Liu Tong, Xiang Xue, Hengzhi Fu, Liangshun Luo, Yanqing Su, Binbin Wang, Yanan Wang, Liang Wang, Junhao Zhao, and Jingjie Guo
- Subjects
Equiaxed crystals ,Materials science ,Mechanical Engineering ,Condensed Matter Physics ,Microstructure ,Mechanics of Materials ,Phase (matter) ,Ultimate tensile strength ,Relative density ,General Materials Science ,Texture (crystalline) ,Selective laser melting ,Composite material ,Ductility - Abstract
The addition of Sc and Zr into an Al–Mg–Mn alloy produced by selective laser melting exhibited exceptional properties. Multiple factors eventually lead to the improvement of properties, such as densification behaviors, grain characteristics, texture and the precipitated phases. We firstly investigate evolution of the melt pool characteristics which are varied under different processing parameters and lead to different solidified microstructures, densification behaviors and corresponding mechanical properties. Meanwhile, the characteristics of melt pool can be predicted through the normalized enthalpy of input energy, which presents more credible relationship with the melt pool dimensions. To this end, the relative density is up to 99.88% when the volume energy density and normalized enthalpy are combined used. Recrystallisation inhabitations induced by the added Sc and Zr is supposed after comparing the grain sizes under different conditions. Regrettably, the relationship between melt pool characteristics and the equiaxed/columnar ratio can not be described accurately, which due to the pseudo-equiaxed regions in XZ/YZ sections through regulating the melt track orientations via 67° scanning rotation. There are dispersed Al6Mn and Al3(Sc, Zr) particles exist in as-fabricated samples result in better mechanical properties and the subsequent aging treatment can further improve the comprehensive mechanical properties. Finally, the ultimate tensile strength and ductility is separately about 494.32 ± 4.16 MPa and 15 ± 1.27% after aging for 4 h at 325 °C. In contrast, the processing parameters have little impact on mechanical properties, especially for the yield strength, mainly owing to the homologous precipitate phase and grain sizes when the relative density is similar. The connection involving the whole periods from solidification to the final mechanical properties is discussed that may offer feasible ideas for alloy design and corresponding parameter optimization.
- Published
- 2021
34. The evolution and characterizations of Al3(ScxZr1-x) phase in Al–Mg-based alloys proceeded by SLM
- Author
-
Liu Tong, Liangshun Luo, Jingjie Guo, Hengzhi Fu, Liang Wang, Xiang Xue, Binbin Wang, Yanan Wang, Yanqing Su, Luo Lei, and Junhao Zhao
- Subjects
Materials science ,Mechanical Engineering ,Alloy ,Nucleation ,Thermodynamics ,engineering.material ,Condensed Matter Physics ,Grain growth ,Mechanics of Materials ,Phase (matter) ,Ultimate tensile strength ,engineering ,Particle ,General Materials Science ,Grain boundary ,Ductility - Abstract
The addition of Sc and Zr endows selective laser melted Al–Mg-based alloys with exceptional properties, which are predominately related to the Al3(ScxZr1-x) precipitates. The Al3(ScxZr1-x) precipitates formed in different stage of processing are identified as primary- Al3(ScxZr1-x) and aged- Al3(ScxZr1-x) according to different crystallographic characteristics. The experimental results show most of primary Al3(ScxZr1-x) particles located in the grain boundaries with incoherent interface and irregular shape, which is seldom reported in conventional casting. In contrast, the subsequent aging brings out more spherical Al3(ScxZr1-x) with coherent interface emerged in the grains. Combined the first-principle calculations with pseudo binary-diagram, we search the possible structures of Al3(ScxZr1-x) based on their formation enthalpy and binding energy, whose space group should be altered as Sc enters the Al3Zr (DO23) dispersoids. The most possible structure of primary Al3(ScxZr1-x) phase is evaluated as Al12Sc3Zr, and the calculated crystallo-graphic parameters are consistent with the experimental results. As the primary Al3(ScxZr1-x) is hard to act as nucleation particle, it can be inferred that the grain refinement resulting from the modification and hindrance of these particles during grain growth. A corresponding ultimate tensile strength and ductility is separately about 521.26 ± 12.30 MPa and 15.83 ± 0.94% after aging at 325 °C for 4 h. The results demonstrate the difference between the primary Al3(ScxZr1-x) and the aged Al3(ScxZr1-x) as well as the formation of primary Al3(ScxZr1-x), which offer a new idea to design new alloy for additive manufacturing.
- Published
- 2021
35. Tuning process parameters to optimize microstructure and mechanical properties of novel maraging steel fabricated by selective laser melting
- Author
-
Liang Wang, Hengzhi Fu, Binbin Wang, Liangshun Luo, Liu Tong, Jingjie Guo, Junhao Zhao, Yanqing Su, Luo Lei, and Yanan Wang
- Subjects
Austenite ,Materials science ,Mechanical Engineering ,Weldability ,engineering.material ,Condensed Matter Physics ,Microstructure ,Mechanics of Materials ,Martensite ,Ultimate tensile strength ,engineering ,General Materials Science ,Composite material ,Selective laser melting ,Ductility ,Maraging steel - Abstract
Maraging steel is a promising material for additive manufacturing due to its ultrahigh yield strength, reasonable ductility and good weldability. However, the ductility of the fabricated part will be degraded after aging treatment. In this regard, we firstly designed a new composition of maraging steel Fe-18.3Ni-9Co-4.84Mo-0.92Ti-0.27Al-0.13Cr-0.01C (wt.%), whose strength and ductility can be simultaneously improved by selective laser melting. The relationship between laser process parameters and forming defects has been studied. Using single-track and single-layer experiments, fully dense parts were fabricated with a certain range of process parameters, corresponding to the 30–50% lap rate in the X–Y plane and 70% remelted rate along Z-axis. Besides, we found film-like reverted austenite along the martensite lath boundaries in the as-fabricated part. The effects of heat treatment processes on the reverted austenite and mechanical properties of the fabricated parts were also studied; the strength-ductility trade-off of maraging steel after heat treatment can be alleviated. The tensile strength and elongation of printed samples after direct aging treatment can respectively reach 2037 MPa and 6.4%, and 2182 MPa, 4.8% after solution and aging treatment.
- Published
- 2021
36. Emulation of an atmospheric gas-phase chemistry solver through deep learning: Case study of Chinese Mainland
- Author
-
Junhao Zhao, Yun Cheng, Shuo Wang, Hairui Zhang, Chang Liu, Zhen Cheng, Juanyong Shen, and Yichao Wang
- Subjects
Atmospheric Science ,Emulation ,Chemical transport model ,Artificial neural network ,business.industry ,Deep learning ,Stability (learning theory) ,Solver ,Residual ,Pollution ,Computational science ,Ordinary differential equation ,Artificial intelligence ,business ,Waste Management and Disposal - Abstract
The solution of atmospheric chemical kinetics is considered as the dominant computationally intensive task in chemical transport models. Reported strategies for improving computational efficiency have not changed the essence of solving ordinary differential equations. In this study, we emulate a typical gas-phase chemistry solver implemented in chemical transport models in Chinese Mainland using a 28-layer residual regression neural network. Validation results have a total R2 of 0.985 with the original numerical solution for 194 species during a single timestep. Multiple-timestep test for one month verified the accuracy and stability of our model while no exponential accumulated bias was observed, though a slow accumulation of biases existed. There were 102 species with R2 values higher than 0.90 and 137 species with daily NMB values below 30% among the 194 species throughout the month. Meanwhile, the computational efficiency of gas-phase chemistry using the deep learning emulator was promoted by 10.6 times on one CPU and 85.2 times on one GPU. Our study confirms the feasibility of emulating an atmospheric chemical kinetic solver with data-driven models through deep learning and represents a step towards a deep learning solver being used in a chemical transport model. The deep learning emulator is expected to not only accelerate atmospheric chemical kinetic solutions by orders of magnitude but also provide a promising pathway for implementing near-explicit rather than lumped chemical mechanisms in chemical transport models.
- Published
- 2021
37. Aluminum and fluorine co-doping for promotion of stability and safety of lithium-rich layered cathode material
- Author
-
Zeheng Yang, Wei Zhang, Junhao Zhao, Xiaoming Fan, Bing Guo, Zhangxian Chen, Sheng Li, and Weixin Zhang
- Subjects
Battery (electricity) ,Materials science ,General Chemical Engineering ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Cathode ,Energy storage ,Lithium-ion battery ,0104 chemical sciences ,law.invention ,Electrochemical cell ,Chemical engineering ,chemistry ,law ,Heat generation ,Electrochemistry ,Lithium ,Thermal stability ,0210 nano-technology - Abstract
Lithium-rich layered compound cathode materials recently attract ever-growing attention in lithium ion batteries for electric vehicles and energy storage devices due to their high discharge capacities of over 250 mAh g −1 and low cost. However, they still suffer from capacity fade, voltage decay and poor rate capability and thermal stability. In this paper, the Al&F co-doped Li 1.2 Ni 0.13 Co 0.13- x Mn 0.54 Al x O 2(1- y ) F 2 y cathode material has been successfully prepared via a co-precipitation reaction and a subsequent solid phase calcination. The resulting material combines the advantages of both Al-doping and F-doping, which can effectively mitigate the intrinsic layered-to-spinel phase transformation, and as a consequence, inhibits the capacity fade and voltage decay: delivering a discharge capacity of 217 mAh g −1 with retention of 88.21% and an average discharge voltage decay of 0.4019 V upon 150 cycling at 0.5 C. On the other side, with an increased electronic and ionic conductivity, this co-doping practice enhances the rate capability by a considerable extent that it delivers a discharge capacity of 157 mAh g −1 at 10 C, thus facilitating its application for quick charging devices. In addition, the thermal stability related with battery safety is significantly meliorated. Specifically, the co-doped cathode material exhibits an initial exothermal peak at a higher temperature of 273 °C and a much less overall heat generation of 221 J g −1 compared to the 210 °C and 755 J g −1 for the pristine one. In conclusion, the anion/cation co-substitution strategy has been demonstrated to be of great promise for the improvement of lithium-rich layered cathode materials.
- Published
- 2017
38. Object Fusion Tracking Based on Visible and Infrared Images Using Fully Convolutional Siamese Networks
- Author
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Xingchen Zhang, Ping Ye, Dan Qiao, Junhao Zhao, Shengyun Peng, and Gang Xiao
- Published
- 2019
39. A Survey on Object Tracking in Aerial Surveillance
- Author
-
Junhao Zhao, Gang Xiao, Durga Prasad Bavirisetti, and Xingchen Zhang
- Subjects
Flexibility (engineering) ,Motion compensation ,Computer science ,business.industry ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,Tracking system ,Common framework ,Tracking (particle physics) ,Object detection ,Video tracking ,Computer vision ,Artificial intelligence ,business - Abstract
Nowadays the Unmanned Aerial Vehicle (UAV) has been widely used due to its low-cost and unique flexibility. Specifically, the high-altitude operational capability makes it the ideal tool in military and civilian surveillance system, in which object tracking based on computer vision is the core ingredient. In this paper, we presented a survey on object tracking methods in aerial surveillance. After briefly reviewing the development history and current research institutions, we summarized frequently used sensors in aerial platform. Then we focused on UAV-based tracking methods by providing detailed descriptions of its common framework (ego motion compensation, object detection, object tracking) and representative tracking algorithms. Through discussing the requirement of a good tracking system and deficiency of current technologies, future directions for aerial surveillance were proposed.
- Published
- 2019
40. A fluoride ion-mediated continuous etching-redeposition strategy to synthesize Si nanocomposites with appropriate SiO
- Author
-
Xiaoming, Fan, Junhao, Zhao, Zeheng, Yang, and Weixin, Zhang
- Abstract
Silicon nanocomposites with surface coating have been promising candidates for high-performance anodes in Li-ion batteries. Here we report a simple yet effective way to synthesize Si@SiO2 nanocomposites with amorphous SiO2 coating through a fluoride ion-mediated continuous etching-redeposition process. The Si@SiO2 nanocomposite anode exhibits significantly improved lithium storage properties, with a reversible capacity of 1356 mA h g-1 at 2.1 A g-1 for 300 cycles.
- Published
- 2018
41. A novel tree-based dynamic heterogeneous ensemble method for credit scoring
- Author
-
Yinguo Li, Junhao Zhao, Mengyi Niu, Yufei Xia, and Lingyun He
- Subjects
0209 industrial biotechnology ,Ensemble forecasting ,Computer science ,business.industry ,General Engineering ,02 engineering and technology ,Overfitting ,Machine learning ,computer.software_genre ,Base (topology) ,Measure (mathematics) ,Computer Science Applications ,Tree (data structure) ,020901 industrial engineering & automation ,Artificial Intelligence ,0202 electrical engineering, electronic engineering, information engineering ,Benchmark (computing) ,020201 artificial intelligence & image processing ,Tree based ,Artificial intelligence ,business ,computer ,Selection (genetic algorithm) - Abstract
Ensemble models have been extensively applied to credit scoring. However, advanced tree-based classifiers have been seldom utilized as components of ensemble models. Moreover, few studies have considered dynamic ensemble selection. To fill the research gap, this paper aims to develop a novel tree-based overfitting-cautious heterogeneous ensemble model (i.e., OCHE) for credit scoring which departs from existing literature on base models and ensemble selection strategy. Regarding base models, tree-based techniques are employed to acquire a balance between predictive accuracy and computational cost. In terms of ensemble selection, the proposed method can assign weights to base models dynamically according to the overfitting measure. Validated on five public datasets, the proposed approach is compared with several popular benchmark models and selection strategies on predictive accuracy and computational cost measures. For predictive accuracy, the proposed approach outperforms the benchmark models significantly in most cases based on the non-parametric significance test. It also performs marginally better than several state-of-the-art studies. Our proposal remains robust in several scenarios. In terms of computational cost, the proposed method provides acceptable performance and benefits from GPU acceleration considerably.
- Published
- 2020
42. Computing Smooth Quasi-geodesic Distance Field (QGDF) with Quadratic Programming
- Author
-
Shuangmin Chen, Junhao Zhao, Guozhu Liu, Jian Xu, Yuanfeng Zhou, Shiqing Xin, Ying He, Luming Cao, and School of Computer Science and Engineering
- Subjects
0209 industrial biotechnology ,Research program ,Smooth Geodesic Distance Field ,Geodesic ,Quadratic Programming ,Computer science ,020207 software engineering ,02 engineering and technology ,Computer Graphics and Computer-Aided Design ,Industrial and Manufacturing Engineering ,Computer Science Applications ,Engineering management ,020901 industrial engineering & automation ,0202 electrical engineering, electronic engineering, information engineering ,Computer science and engineering [Engineering] ,Quadratic programming ,Informatization ,China - Abstract
Computing geodesic distances on polyhedral surfaces is an important task in digital geometry processing. Speed and accuracy are two commonly-used measurements of evaluating a discrete geodesic algorithm. In applications, such as parametrization and shape analysis, a smooth distance field is often preferred over the exact, non-smooth geodesic distance field. We use the term Quasi-geodesic Distance Field (QGDF) to denote a smooth scalar field that is as close as possible to an exact geodesic distance field. In this paper, we formulate the problem of computing QGDF into a standard quadratic programming (QP) problem which maintains a trade-off between accuracy and smoothness. The proposed QP formulation is also flexible in that it can be naturally extended to point clouds and tetrahedral meshes, and support various user-specified constraints. We demonstrate the effectiveness of QGDF in defect-tolerant distances and symmetry-constrained distances. The authors would like to thank the anonymous reviewers for their valuable comments and suggestions. This work is supported by National Natural Science Foundation of China (61772016, 61772312), the NSFC-Zhejiang Joint Fund for the Integration of Industrialization and Informatization (U1909210), the Dalian University of Technology 2019 Discipline Platform Fund (1000-82212201), the National Young Talents Program of China, and the Strategic Priority Research Program of Chinese Academy of Science (XDA21010205).
- Published
- 2020
43. Smoke detection in video using dissipation function and support vector machine
- Author
-
Qiang Zhang, Cui Hong, Jia Zhai, Junhao Zhao, and Jiaohao Zhang
- Subjects
genetic structures ,Channel (digital image) ,Computer science ,business.industry ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,020101 civil engineering ,02 engineering and technology ,Dissipation ,0201 civil engineering ,Support vector machine ,Transformation (function) ,Wavelet ,Feature (computer vision) ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Computer vision ,Depth of field ,Bilateral filter ,Artificial intelligence ,business ,ComputingMethodologies_COMPUTERGRAPHICS - Abstract
A method for smoke detection in video is proposed. The camera monitoring the scene is assumed to be stationary. With the atmospheric scattering model, dissipation function is reflected the transmissivity between the background objects in the scene and the camera. Dark channel prior and fast bilateral filter are used for estimating dissipation function which is only the function of the depth of field. Based on dissipation function, visual background extractor (ViBe) can be used for detecting smoke as a result of smoke’s motion characteristics as well as detecting other moving targets. Later on, various characteristics of smoke are extracted. Color feature and high-frequency energy based on wavelet transformation is selected to constitute the final recognition vectors, and Support vector machine (SVM) is used as a classification model. The final experimental results show that the accuracy rate of this method for smoke detection can reach 90.1%.
- Published
- 2018
44. Research on Respiratory Signal Based on Angular Velocity
- Author
-
Guo Dan, Xiaohong Weng, Huanyu Yang, Zhemin Zhu, and Junhao Zhao
- Subjects
medicine.anatomical_structure ,Suprasternal notch ,Respiratory rate ,Computer science ,Acoustics ,medicine ,Median filter ,Waveform ,Angular velocity ,Respiratory system ,medicine.disease_cause ,Signal ,Nasal cannula - Abstract
Precise monitoring of human respiration is crucial to the diagnosis of a wide range of respiratory and cardiovascular disorders and (thus) is of great interest to both clinicians and researchers. Existing measurements may include electrocardiography (ECG), nasal cannula and respiratory plethysmography. However, low comfort levels and signal shifts which are often observed in these techniques pose limitations for long-term, accurate monitoring of human respiration. In this paper, we develop a convenient respiratory signal acquisition method based on angular velocity derived from suprasternal notch. Research has found that waveforms collected from the suprasternal notch display higher robustness, as well as less gender variability. We use the median filter method and intersection detection technique to extract the respiratory waveform, respiratory frequency and respiratory phase parameters. And validated the respiratory signals derived from suprasternal angular velocity in both males and females. The extracted parameters are validated against a carbon dioxide concentration acquisition device, which serves as our golden reference platform. The results demonstrate the potential of suprasternal-derived angular velocity as a simple, low-cost and unobtrusive method for monitoring human respiration.
- Published
- 2018
45. An improved long-term correlation tracking method with occlusion handling
- Author
-
Gang Xiao, Xingchen Zhang, Durga Prasad Bavirisetti, and Junhao Zhao
- Subjects
business.industry ,Computer science ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,010309 optics ,Correlation ,Optics ,Robustness (computer science) ,Video tracking ,0103 physical sciences ,Occlusion ,Computer vision ,Artificial intelligence ,Electrical and Electronic Engineering ,business ,Long term correlation - Abstract
By improving the long-term correlation tracking (LCT) algorithm, an effective object tracking method, improved LCT (ILCT), is proposed to address the issue of occlusion. If the object is judged being occluded by the designed criterion, which is based on the characteristic of response value curve, an added re-detector will perform re-detection, and the tracker is ordered to stop. Besides, a filtering and adoption strategy of re-detection results is given to choose the most reliable one for the re-initialization of the tracker. Extensive experiments are carried out under the conditions of occlusion, and the results demonstrate that ILCT outperforms some state-of-the-art methods in terms of accuracy and robustness.
- Published
- 2019
46. The Harmony and Strategy of Chinese Basketball Association
- Author
-
Guanghui Guo and Junhao Zhao
- Subjects
Basketball ,business.industry ,media_common.quotation_subject ,Advertising ,Public relations ,business ,Morality ,Psychology ,Stadium ,media_common - Abstract
This study discussed the harmony of Chinese Basketball Association (CBA). We found that inharmonious factors include the audiences violence, athletes violence, referees’ qualification and black whistle. Based on these studies we proposed several strategies for creating harmonious competition: the Basketball Management Center has to establish necessary management and legal systems; the clubs have to improve the stadium security and the course condition; the audience and fans must set up correct attitude and improve their ball ethics; the athletes, coaches and referees need to strengthen their own occupation morality. Keywords—CBA, harmony, stadium violence
- Published
- 2014
47. Current Situation and Strategic Suggestions of Physical Education Teachers in Hubei Vocational Colleges
- Author
-
Guanghui Guo and Junhao Zhao
- Subjects
Higher education ,Age structure ,business.industry ,Vocational education ,Political science ,education ,Mathematics education ,business ,Literature survey ,Professional standards ,Physical education ,Lower degree - Abstract
This study used literature survey and questionnaire methods to investigate the age structure, research ability, professional standards, education levels and other aspects of physical education teachers in Hubei Vocational Colleges. The results indicated that the age structure of the faculty in higher vocational colleges in Hubei province is reasonable, but there are still some problems, such as a serious imbalance in the ratio of teachers and students, lower degree of full-time teachers, and lack of scientific research ability. In order to solove these problems, this study came up with several suggestions and strategies to improve the qualification of physical education teachers in vocational colleges. Keywords—Hubei, Higher vocational colleges and universities, physical education teachers, strategy
- Published
- 2014
48. On the Vision of Basketball Players
- Author
-
Guanghui Guo and Junhao Zhao
- Subjects
Basketball ,Character (mathematics) ,Aesthetics ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Mathematics education ,Psychology ,Limited vision - Abstract
In basetball teaching and training, many teachers/coaches often overlook the vision practice of students or players. The limited vision affects the technical and stratigical level of the whole team. In this study, I conducted systematical and scientific analyses on the character of basketball players’ vision, the effecting factors of vision, and raised some suggestions for training. Keywords—vision, characters of vision, effecting factors, training suggestions
- Published
- 2014
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