27 results on '"Li, Guangyun"'
Search Results
2. Large-scale spatial data visualization method based on augmented reality
- Author
-
Qiao, Xiaoning, Xie, Wenming, Peng, Xiaodong, Li, Guangyun, Li, Dalin, Guo, Yingyi, and Ren, Jingyi
- Published
- 2024
- Full Text
- View/download PDF
3. Research and development of indoor positioning technology based on visible light communication
- Author
-
Li, Guangyun, Sun, Senzhen, Gao, Yangjun, Li, Ang, and Zhu, Kailin
- Published
- 2023
- Full Text
- View/download PDF
4. Extraction of local structure information of point clouds through space-filling curve for semantic segmentation
- Author
-
Xiang, Xueyong, Wang, Li, Zong, Wenpeng, and Li, Guangyun
- Published
- 2022
- Full Text
- View/download PDF
5. Biological and physiological effects in Bemisia tabaci feeding on tomatoes endophytically colonized by Beauveria bassiana.
- Author
-
Wang, Xian, Yuan, Qian, He, Liqiang, Wang, Zhou, Li, Guangyun, Wang, Ziying, and Liu, Huai
- Subjects
SWEETPOTATO whitefly ,BEAUVERIA bassiana ,PLANT life cycles ,TOMATOES ,LIFE cycles (Biology) ,ANIMAL feeds - Abstract
BACKGROUND: Entomopathogenic fungi (EPF) treatment of plants may affect the survival and feeding preferences of herbivorous pests. However, comprehensive studies on the fitness across their entire life cycle, feeding behavior, and physiological changes in herbivores consuming EPF‐treated plants within the tripartite interactions of EPF, plants, and pests are still limited. In this study, we utilized life tables, electrical penetration graph (EPG), and metabolomics to uncover the biological and physiological characteristics of Bemisia tabaci on tomato plants inoculated with Beauveria bassiana through root irrigation. RESULTS: Our study indicated that Beauveria bassiana Bb252 can penetrate the entire tissue from the point of inoculation, primarily colonizing the intercellular spaces and vascular tissue. However, this colonization is temporary, lasting no more than 35 days. Moreover, the population fitness and feeding behavior of Bemisia tabaci on tomato plants treated with Beauveria bassiana via root irrigation were significantly affected, showing a substantial 41.4% decrease in net reproductive rate (R0), a notable reduction in watery salivation, and shortened phloem ingestion. Lastly, we observed a significant decrease in hormones and amino acids of whiteflies that fed on Beauveria bassiana‐treated tomato plants by root irrigation. CONCLUSIONS: Our results indicated that the endophyte, Beauveria bassiana Bb252, reduced demographic fitness of Bemisia tabaci by altering its hormones and amino acids levels. These findings enhance our understanding of multitrophic interactions in integrated pest management. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
6. Polyphenolic Nanomedicine Regulating Mitochondria REDOX for Innovative Cancer Treatment.
- Author
-
Yang, Mingchuan, He, Yufeng, Ni, Qingqing, Zhou, Mengxue, Chen, Hongping, Li, Guangyun, Yu, Jizhong, Wu, Ximing, and Zhang, Xiangchun
- Subjects
PHOTOTHERMAL conversion ,HOMEOSTASIS ,NANOMEDICINE ,MITOCHONDRIA ,RESEARCH personnel - Abstract
Cancer remains a highly lethal disease globally. The approach centered on REDOX-targeted mitochondrial therapy for cancer has displayed notable benefits. Plant polyphenols exhibit strong REDOX and anticancer properties, particularly by affecting mitochondrial function, yet their structural instability and low bioavailability hinder their utility. To overcome this challenge, researchers have utilized the inherent physical and chemical characteristics of polyphenols and their derivatives to develop innovative nanomedicines for targeting mitochondria. This review examines the construction strategies and anticancer properties of various types of polyphenol-based biological nanomedicine for regulating mitochondria in recent years, such as polyphenol self-assembly, metal–phenol network, polyphenol–protein, polyphenol–hydrogel, polyphenol–chitosan, and polyphenol–liposome. These polyphenolic nanomedicines incorporate enhanced features such as improved solubility, efficient photothermal conversion capability, regulation of mitochondrial homeostasis, and ion adsorption through diverse construction strategies. The focus is on how these polyphenol nanomedicines promote ROS production and their mechanism of targeting mitochondria to inhibit cancer. Furthermore, it delves into the benefits and applications of polyphenolic nanomedicine in cancer treatments, as well as the challenges for future research. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
7. Three time spoofing algorithms for GNSS timing receivers and performance evaluation
- Author
-
Gao, Yangjun and Li, Guangyun
- Published
- 2022
- Full Text
- View/download PDF
8. A survey on deep learning-based precise boundary recovery of semantic segmentation for images and point clouds
- Author
-
Zhang, Rui, Li, Guangyun, Wunderlich, Thomas, and Wang, Li
- Published
- 2021
- Full Text
- View/download PDF
9. SLAM integrated mobile mapping system in complex urban environments
- Author
-
Li, Shuaixin, Li, Guangyun, Wang, Li, and Qin, Yuchu
- Published
- 2020
- Full Text
- View/download PDF
10. Fusion of images and point clouds for the semantic segmentation of large-scale 3D scenes based on deep learning
- Author
-
Zhang, Rui, Li, Guangyun, Li, Minglei, and Wang, Li
- Published
- 2018
- Full Text
- View/download PDF
11. A three-dimensional robust ridge estimation positioning method for UWB in a complex environment
- Author
-
Li, Shuaixin, Li, Guangyun, Wang, Li, Zhou, Yanglin, Peng, Yifan, and Fu, Jingyang
- Published
- 2017
- Full Text
- View/download PDF
12. A new asynchronous traction signal spoofing algorithm for PLL-assisted DLL receiver.
- Author
-
Gao, Yangjun and Li, Guangyun
- Abstract
The global navigation satellite system (GNSS) spoofing technology is an important method to control the targets that pose threats and protect sensitive areas. Traction spoofing can gradually take over the tracking loop by spoofing signals. To achieve more covert spoofing of a receiver configured with phase lock loop (PLL) assisted delay lock loop (DLL) loop, the following research work has been carried out: First, the response of the combined loop to GNSS spoofing is analyzed; Second, a new asynchronous traction signal spoofing algorithm is proposed; in the design of the code rate and carrier frequency of spoofing signal, the dynamic performance of the loop is fully considered, while maintaining a good consistency with the carrier frequency. In the design of the power of the spoofing signal, the success rate of spoofing is improved as much as possible while avoiding absolute power monitoring. Finally, the calculation method of the parameters of the spoofing signal is given. Third, by building the GNSS signal generation software and software receiver platform to carry out experimental verification and through experimental comparison and analysis with many existing representative spoofing schemes, it is proved that the new algorithm can successfully achieve spoofing. The spoofing takes 107.8 s, which makes the local code rate increase 0.03 Hz, the carrier frequency increase 50 Hz, the average value of consistency spoofing detection is 9.40 × 10
−3 , and finally stabilized at the convergence value − 2.95 × 10−8 , that is, during the spoofing process, spoofing signal maintains the consistency of the authentic signal, which can well avoid the consistency spoofing detection of the receiver, the effectiveness and superiority of the proposed algorithm compared with other spoofing methods are fully verified. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
13. Prey life stages modulate effects of predation stress on prey lifespan, development, and reproduction in mites.
- Author
-
Wei, Xiaoying, Li, Guangyun, and Zhang, Zhi‐Qiang
- Subjects
- *
PREDATION , *LIFE history theory , *REPRODUCTION , *MITES , *OVIPARITY , *FERTILITY , *LARVAE - Abstract
The non‐consumptive effects of predator‐induced stress can influence a variety of life‐history traits. Many previous studies focused only on short‐term effects such as development and reproductive rates. Recent studies have showed that long‐term predation stress (given during the whole life of the prey) and short‐term predation stress (provided during the immature stage of the prey) could generate completely opposite results: the former could decrease lifespan, whereas the later could increase lifespan. However, it is still unclear whether the advantage is because of the short duration of exposure or the early stage of life during which exposure was exerted. Thus, in this study, the prey (Tyrophagus putrescentiae) was exposed to predation stress from the predator (Neoseiulus cucumeris) during different life stages (larva, protonymph, tritonymph, first 5 d of oviposition, the full lifespan or none of the above). The results showed that the predation stress supplied during larval and protonymphal stage delayed development, reduced fecundity and prolonged lifespan of the prey, while the stress given during tritonymphal stage only reduced lifespan slightly and the stress given during the first 5 d of oviposition did not change lifespan but reduced fecundity. This study indicated that the effects of predation stress are dependent on prey life stage and the predation stress experienced in the early life stages is important to lifespan modulation. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
14. Intraguild Prey Served as Alternative Prey for Intraguild Predators in a Reciprocal Predator Guild between Neoseiulus barkeri and Scolothrips takahashii.
- Author
-
Liu, Mingxiu, Wang, Mian, Nima, Yuzhen, Feng, Xiaotian, Li, Guangyun, Yang, Yi, Li, Yaying, and Liu, Huai
- Subjects
PREDATION ,TWO-spotted spider mite ,EGGS ,OVIPARITY ,PREDATORY mite ,PREDATORY animals ,BIOLOGICAL pest control agents ,FOOD shortages - Abstract
Simple Summary: Intraguild predation between the introduced enemy Neoseiulus barkeri (Hughes) and the native enemy Scolothrips takahashii (Priesner) frequently occurs when target prey is scarce. It is hypothesized that intraguild predation is an adaptative strategy for predators, ensuring the persistence of the intraguild predators during periods of prey scarcity. Therefore, we undertook a study to evaluate the effects of the intraguild prey on the survival, development and reproduction of intraguild predators in a reciprocal predator guild with N. barkeri and S. takahashii. Our results support the hypothesis, showing that intraguild prey enhanced the survival, development and oviposition of intraguild predators, further confirming the effectiveness of intraguild predation as an adaptative strategy. The predatory mites Neoseiulus barkeri (Hughes) and the predatory thrips Scolothrips takahashii (Priesner) are known as potential biocontrol agents for the two-spotted spider mite Tetranychus urticae (Koch). These two predator species occur simultaneously on crops in agricultural ecosystems and are proved to be involved in life-stage specific intraguild predation. The intraguild prey may play a role in securing the persistence of the intraguild predators during food shortage periods. To understand the potential of intraguild prey as food source for intraguild predators in the N. barkeri and S. takahashii guild at low T. urticae densities, the survival, development and reproduction of both predators was determined when fed on heterospecific predators. The choice tests were conducted to determine the preference of the intraguild predator between the intraguild prey and the shared prey. Results showed that 53.3% N. barkeri and 60% S. takahashii juveniles successfully developed when fed on heterospecific predators. Female intraguild predators of both species fed on intraguild prey survived and laid eggs throughout the experiment. In the choice test, both intraguild predator species preferred their extraguild prey T. urticae. This study suggested that intraguild prey served as an alternative prey for intraguild predators prolonged survival and ensured the reproduction of intraguild predators during food shortage, ultimately decreasing the need for the continual release of the predators. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
15. Preparation of Micron-Sized TS‑1 Spherical Membrane Catalysts and Their Performance in the Epoxidation of Chloropropene.
- Author
-
Tang, Guoqiang, Li, Yichuan, Yang, Zhaosheng, Wang, Yu, Li, Guangyun, Wang, Yilou, Chai, Yong-Ming, and Liu, Chenguang
- Published
- 2023
- Full Text
- View/download PDF
16. InTEn-LOAM: Intensity and Temporal Enhanced LiDAR Odometry and Mapping.
- Author
-
Li, Shuaixin, Tian, Bin, Zhu, Xiaozhou, Gui, Jianjun, Yao, Wen, and Li, Guangyun
- Subjects
LIDAR ,FEATURE extraction ,OPTICAL radar ,TECHNOLOGICAL innovations ,MOTION capture (Human mechanics) ,EXERCISE intensity - Abstract
Traditional LiDAR odometry (LO) systems mainly leverage geometric information obtained from the traversed surroundings to register lazer scans and estimate LiDAR ego-motion, while they may be unreliable in dynamic or degraded environments. This paper proposes InTEn-LOAM, a low-drift and robust LiDAR odometry and mapping method that fully exploits implicit information of lazer sweeps (i.e., geometric, intensity and temporal characteristics). The specific content of this work includes method innovation and experimental verification. With respect to method innovation, we propose the cylindrical-image-based feature extraction scheme, which makes use of the characteristic of uniform spatial distribution of lazer points to boost the adaptive extraction of various types of features, i.e., ground, beam, facade and reflector. We propose a novel intensity-based point registration algorithm and incorporate it into the LiDAR odometry, enabling the LO system to jointly estimate the LiDAR ego-motion using both geometric and intensity feature points. To eliminate the interference of dynamic objects, we propose a temporal-based dynamic object removal approach to filter them out in the resulting points map. Moreover, the local map is organized and downsampled using a temporal-related voxel grid filter to maintain the similarity between the current scan and the static local map. With respect to experimental verification, extensive tests are conducted on both simulated and real-world datasets. The results show that the proposed method achieves similar or better accuracy with respect to the state-of-the-art in normal driving scenarios and outperforms geometric-based LO in unstructured environments. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
17. Two Regional Deployment Algorithms of Distributed GNSS Forwarding Spoofer for Multiple Receiver Sensors.
- Author
-
Gao, Yangjun and Li, Guangyun
- Subjects
- *
GLOBAL Positioning System , *TRANSMITTERS (Communication) , *DETECTORS , *DISTRIBUTED algorithms , *FOREIGN bodies - Abstract
Global navigation satellite system (GNSS) spoofing technology is an effective way to protect sensitive facilities and control foreign objects. To realize effective distributed GNSS forwarding spoofing for multiple receiver sensors in the area, the following research work is carried out: first, the GNSS forwarding spoofing model is established, including a forwarding spoofing mathematical model and an asynchronous traction spoofing method; second, the function scope of forwarding spoofing is fully evaluated; third, two forwarding spoofer area deployment algorithms for multi-spoofer multi-target (MSMT) are proposed—the multi-target same-point spoofing algorithm (MSPSA) is suitable for the same-point spoofing of multiple receiver sensors, and the multi-target different-point spoofing algorithm (MDPSA) is suitable for the different-point spoofing of multiple receiver sensors; and four, the experimental tests of MSPSA and MDPSA for MSMT were carried out. The experimental results show that MSPSA and MDPSA can respectively give the most appropriate deployment scheme of spoofing according to the various needs of the spoofer. For example, the number of spoofing devices is 1, the total distance between each spoofer and each receiver is 40,345.1 m, and the critical spoofing rate (CSR) and spoofing success rate (SSR) are both 100%. The performance of the spoofing deployment scheme can meet the needs of the spoofer. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
18. A New GNSS Spoofing Signal Power Control Algorithm for Receiver Sensors in Acquisition Phase and Subsequent Control.
- Author
-
Gao, Yangjun and Li, Guangyun
- Subjects
- *
DETECTORS , *ARTIFICIAL satellites in navigation , *ALGORITHMS , *THRESHOLDING algorithms - Abstract
Satellite navigation spoofing technology has become a hotspot of interference technology research because of its significant threat and high concealment. In a spoofing scenario, suppressive interference is typically used to ensure that the target receiver sensor is in the unlocked and reacquisition state, and then spoofing is implemented. This method has a high feasibility, and the power of the spoofing signal affects the concealment and efficiency of spoofing. Currently, there is limited research involving the GNSS spoofing signal power control. Moreover, there is no systematic complete power control scheme, most of which is limited to qualitative or simulation, and the actual application effect is still unclear. Therefore, a new GNSS spoofing signal power control algorithm under the power constraints of the receiver sensor in the acquisition phase and the subsequent control is proposed. The experimental platform is designed to prove that compared with the conventional spoofing signal high power control algorithm, the new GNSS spoofing signal power control algorithm shortens Doppler frequency fluctuation time by 72.2% and reduces the range by 75.9%. The carrier-to-noise ratio of the received signal is less than the threshold of the receiver sensor, and the range of three-dimensional coordinates of Earth-Centered, Earth-Fixed (ECEF) is significantly reduced during the spoofing signal taking over receiver sensor, this shows that the new design of the GNSS spoofing signal power control algorithm can make spoofing behavior more hidden, and it will make it more difficult for the target receiver sensor to detect spoofing behavior. The designed algorithm can take over the receiver sensor stealthily with the help of suppressing interference and then pull the bias positioning results, which has good feasibility and effectiveness. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
19. A Slowly Varying Spoofing Algorithm Avoiding Tightly-Coupled GNSS/IMU With Multiple Anti-Spoofing Techniques.
- Author
-
Gao, Yangjun and Li, Guangyun
- Subjects
- *
GLOBAL Positioning System , *AIR filters , *ALGORITHMS , *MODEL airplanes - Abstract
Vehicle and airborne navigation users are facing more and more complex signal interference and even spoofing. If vehicles and aircraft do not strengthen their anti-spoofing ability, their navigation performance is bound to be adversely affected. global navigation satellite system (GNSS) spoofing technology has gradually become a preferred interference method for spoofer because of its high concealment and great harm. For spoofer, user terminal increasingly adopts GNSS with inertial measurement unit (IMU): tightly-coupled GNSS/IMU, on this basis, user also configures a variety of anti-spoofing techniques to effectively deal with spoofing. Even if spoofer slowly changes user's positioning, if spoofing strategy is unreasonable, it will lead to the violation of parameter rationality of coupled filter output parameters and spoofing observation, which greatly increases the difficulty of spoofing. In view of the above problems, from the perspective of spoofer, in order to effectively counter the non cooperative target of assembling tightly-coupled GNSS/IMU by using GNSS spoofing, this paper establishes GNSS spoofing mathematical model, and proposes a slowly varying spoofing algorithm to avoid tightly-coupled GNSS/IMU with multiple anti-spoofing techniques based on the analysis of the influence mechanism of spoofing on the positioning of tightly-coupled GNSS/IMU, the algorithm proposes a measurement deviation determination method to avoid a variety of anti-spoofing techniques, which can gradually pull the positioning results of coupled system, and successfully avoid anti-spoofing techniques detection of least squares residual receiver autonomous integrity monitoring (RAIM) and parameter rationality check. The experimental results show that the algorithm can gradually change positioning of tightly-coupled GNSS/IMU within 30 s, and the north, east and down displacements basically achieve the spoofing effect, the errors with the expected offset are −0.5 m, 1.9 m and 12.7 m respectively. At the same time, the detection of the above anti-spoofing techniques is avoided. The mean value of test statistics for tightly-coupled system is reduced by 75.4% and does not exceed the alarm threshold, so as to achieve the purpose of spoofing, the effectiveness and high concealment of the spoofing algorithm are proved. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
20. A Slowly Varying Spoofing Algorithm on Loosely Coupled GNSS/IMU Avoiding Multiple Anti-Spoofing Techniques.
- Author
-
Gao, Yangjun and Li, Guangyun
- Subjects
- *
GLOBAL Positioning System , *RADAR interference , *ARTIFICIAL satellites in navigation - Abstract
When satellite navigation terminal sensors encounter malicious signal spoofing or interference, if attention is not paid to improving their anti-spoofing ability, the performance of the sensors will be seriously affected. The global navigation satellite system (GNSS) spoofing has gradually become a research hotspot of the jammer because of its great harm and high concealment. In the face of more and more sensors coupling GNSS and inertial measurement unit (IMU) to varying degrees and configuring a variety of anti-spoofing techniques to effectively detect spoofing, even if the spoofer intends to gradually pull the positioning results, if the spoofing strategy is unreasonable, the parameters of the coupled filter output and spoofing observation measurement will lose their rationality, which will lead to the spoofing being detected. To solve the above problems, in order to effectively counter the non-cooperative target sensors of assembling loosely coupled GNSS/IMU using GNSS spoofing, based on the analysis of the influence mechanism of spoofing on the positioning of loosely coupled GNSS/IMU, a slowly varying spoofing algorithm to avoid loosely coupled GNSS/IMU with multiple anti-spoofing techniques is proposed in this paper, and a measurement deviation determination method to avoid multiple anti-spoofing techniques is proposed, which can gradually pull the positioning results of the coupled system and successfully avoid the detection of anti-spoofing techniques of innovation sequence monitoring and a rationality check on parameters. Simulation experimental results show that the proposed algorithm gradually changes the positioning of loosely coupled GNSS/IMU, the north and east displacements achieve the purpose of spoofing, and error with expected offset is −0.2 m and 2.3 m, respectively. Down displacement also basically achieves the purpose of spoofing, and error with the expected offset is 13.2 m. At the same time, the spoofer avoids the detection of multiple anti-spoofing techniques, does not trigger the system alarm, and realizes the purpose of spoofing; thus, the effectiveness and high concealment of the spoofing algorithm are verified. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
21. KdO-Net: Towards Improving the Efficiency of Deep Convolutional Neural Networks Applied in the 3D Pairwise Point Feature Matching.
- Author
-
Zhang, Rui, Li, Guangyun, Wiedemann, Wolfgang, and Holst, Christoph
- Subjects
- *
ARTIFICIAL neural networks , *CONVOLUTIONAL neural networks , *POINT cloud , *FEATURE extraction - Abstract
In this work, we construct a Kd–Octree hybrid index structure to organize the point cloud and generate patch-based feature descriptors at its leaf nodes. We propose a simple yet effective convolutional neural network, termed KdO-Net, with Kd–Octree based descriptors as input for 3D pairwise point cloud matching. The classic pipeline of 3D point cloud registration involves two steps, viz., the point feature matching and the globally consistent refinement. We focus on the first step that can be further divided into three parts, viz., the key point detection, feature descriptor extraction, and pairwise-point correspondence estimation. In practical applications, the point feature matching is ambiguous and challenging owing to the low overlap of multiple scans, inconsistency of point density, and unstructured properties. To solve these issues, we propose the KdO-Net for 3D pairwise point feature matching and present a novel nearest neighbor searching strategy to address the computation problem. Thereafter, our method is evaluated with respect to an indoor BundleFusion benchmark, and generalized to a challenging outdoor ETH dataset. Further, we have extended our method over our complicated and low-overlapped TUM-lab dataset. The empirical results graphically demonstrate that our method achieves a superior precision and a comparable feature matching recall to the prior state-of-the-art deep learning-based methods, despite the overlap being less than 30 percent. Finally, we implement quantitative and qualitative ablated experiments and visualization interpretations for illustrating the insights and behavior of our network. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
22. Reducing nitrogen fertilizer usage coupled with organic substitution improves soil quality and boosts tea yield and quality in tea plantations.
- Author
-
Wang, Biao, Wang, Shang, Li, Guangyun, Fu, Libo, Chen, Hua, Yin, Mei, and Chen, Jianfeng
- Subjects
- *
NITROGEN fertilizers , *ORGANIC fertilizers , *SOIL quality , *TEA plantations , *CROP yields - Abstract
BACKGROUND RESULTS CONCLUSION The utilization of chemical fertilizers is a key measure for maintaining tea yield and quality, but excessive use has negative environmental impacts. The substitution of chemical fertilizer with organic fertilizer has been promoted to sustain crop yield and soil quality. However, knowledge gaps regarding the effects of organic substitution on soil quality and tea yield in tea plantations still exist.A field experiment was conducted to investigate the influence of organic substitution treatments (i.e. 25% partial substitution: biogas slurry + green manure + formula fertilizer, BFG; sheep manure + formula fertilizer, OFF; 100% complete substitution: sheep manure + green manure, OG) on the soil quality, tea yield and quality, and nitrogen utilization efficiency in southwestern China. Results showed that all organic substitution treatments slightly increased soil pH, and significantly increased soil organic matter by 13.22–14.88% compared to conventional fertilization (CF). The BFG treatment was the most effective in enhancing the soil quality index, showing increases of 16.80%, 8.37% and 24.87% higher than the CF, OFF and OG treatments, respectively. Tea yield significantly increased under the BFG, OFF and OG treatments by 11.97%, 13.58% and 5.90% compared to CF, respectively. The BFG treatment increased the amino acid content by 7.78% and decreased the tea polyphenol/amino acid ratio by 6.87%. Additionally, the BFG, OFF and OG treatments greatly increased the nitrogen utilization efficiency of young sprouts by 70.71%, 82.54% and 34.28%, respectively.Overall, partial organic substitution could effectively improve soil quality while maintaining tea yield. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
23. Short-Term Traffic Flow Prediction with Recurrent Mixture Density Network.
- Author
-
Chen, Mingjian, Chen, Rui, Cai, Fu, Li, Wanli, Guo, Naikun, and Li, Guangyun
- Subjects
TRAFFIC flow ,DEEP learning ,RECURRENT neural networks ,INTELLIGENT transportation systems ,TRAFFIC congestion ,SITUATIONAL awareness - Abstract
Traffic situation awareness is the key factor for intelligent transportation systems (ITS) and smart city. Short-term traffic flow prediction is one of the challenging tasks of traffic situation awareness, which is useful for route planning, traffic congestion alleviation, emission reduction, and so on. Over the past few years, ubiquitous location acquisition techniques and sensors digitized the road networks and generated spatiotemporal data. Massive traffic data provide an opportunity for short-term traffic flow prediction in a data-driven manner. Most of the existing short-term traffic flow prediction methods can be divided into two categories: nonparametric and parametric. Traditional parametric methods failed to obtain accurate prediction, due to the nonlinear and stochastic characteristics of short-term traffic flow. Recently, deep learning methods have been studied widely in the fields of short-term prediction. These nonparametric methods yielded promising results in practical experiments. Motivated by the current study status, we dedicate this paper to a short-term traffic flow prediction approach based on the recurrent mixture density network, the combination of recurrent neural network (RNN), and mixture density network (MDN). This approach is implemented on real-world traffic flow data and demonstrates the prominent superiority. To the best of our knowledge, this is the first time that the recurrent mixture density network is applied to a real-world short-term traffic flow prediction task. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
24. A Fast and Accurate Planar-Feature-Based Global Scan Registration Method.
- Author
-
Zong, Wenpeng, Li, Minglei, Zhou, Yanglin, Wang, Li, Xiang, Fengzhuo, and Li, Guangyun
- Abstract
Scan registration is the basis of LiDAR-based mapping and localization. When a good initial guess is available, classical local registration algorithms such as iterative closet point (ICP) and normal distributions transform (NDT) can be utilized. However, scan registration without odometer or inertial measurement unit (IMU) is still an open problem. After reviewing the existing methods, we summarize a modular planar-feature-based registration framework. Based on the idea of modular design, we present a novel global scan registration method based on planar features. A modified renormalization-based algorithm considering the sensor noise model is derived and used for accurate plane fitting and covariance computing. An efficient adaptive plane segmentation algorithm is employed to extract planar patches which is based on voxel growing. A novel projected-image-based method is utilized for fast plane attribute calculation. The attributes of individual planes and relation constrains between the planes are employed to robustly build plane correspondences. The plane-plane singular value decomposition (SVD) method is used to estimate the transform, and normalization of the point coordinates is adopted to further improve accuracy. A consensus metric is introduced to determine plane correspondences and transform solution updating, and to select the optimal solution using the distance from the centroid of one plane to its conjugate plane. Extensive comparative experiments were performed on four datasets covering different structured scenarios to evaluate the performance of the proposed registration method. The experimental results demonstrate that the proposed method achieves a better balance between accuracy and efficiency, and has more stable and robust performance across different scenarios compared to all tested state-of-the-art algorithms. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
25. Kukoamine A attenuates insulin resistance and fatty liver through downregulation of Srebp-1c.
- Author
-
Li, Guangyun, Zhou, Fang, Chen, Ying, Zhang, Weiguo, and Wang, Ning
- Subjects
- *
INSULIN resistance , *FATTY liver , *DOWNREGULATION , *FATTY degeneration , *PALMITIC acid - Abstract
Nonalcoholic fatty liver disease (NAFLD) refers to a pathological condition of hepatic steatosis. Insulin resistance is believed to be the key mechanism mediating initial accumulation of fat in the liver, resulting in hepatic steatosis. Kukoamine A (KuA), a spermine alkaloid, is a major bioactive component extracted from the root barks of Lycium chinense (L. chinense) Miller. In the current study, we aimed to explore the possible effect of KuA on insulin resistance and fatty liver. We showed that KuA significantly inhibited the increase of fasting blood glucose level and insulin level, and the glucose levels in response to glucose and insulin load in HFD-fed mice, which was in a dose-dependent manner. KuA dose-dependently decreased the histological injury of liver, levels of hepatic triglyceride (TG), and serum AST and ALT activities in HFD-fed mice. The increase of serum levels of TNFɑ, IL-1β, IL-6 and C reactive protein in HFD-fed mice was inhibited by KuA. HFD feeding-induced increase of hepatic expression of Srebp-1c and its target genes, including fatty acid synthase (FAS) and acetyl CoA carboxylase 1 (ACC1), was significantly inhibited by KuA. Moreover, upregulation of Srebp-1c notably inhibited KuA-induced improvement of insulin-stimulated glucose uptake, decrease of lipid accumulation and H 2 O 2 level in palmitic acid-treated AML-12 cells. In conclusion, we reported that KuA inhibited Srebp-1c and downstream genes expression and resulted in inhibition of lipid accumulation, inflammation, insulin resistance and oxidative stress. Overall, our results provide a better understanding of the pharmacological activities of KuA against insulin resistance and hepatic steatosis. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
26. Serum 25-Hydroxyvitamin D Levels and Prognosis in Hematological Malignancies: A Systematic Review and Meta-Analysis.
- Author
-
Wang, Wei, Li, Guangyun, He, Xiaoyan, Gao, Jian, Wang, Robin, Wang, Yangang, and Zhao, Wenjuan
- Subjects
- *
COLON cancer prognosis , *VITAMIN D , *BLOOD serum analysis , *HEMATOLOGY , *SYSTEMATIC reviews , *META-analysis - Abstract
Background/Aims: Serum 25-hydroxyvitamin D [25(OH)D] levels proved to be associated with prognosis of patients with colorectal cancer or breast cancer, but its prognostic role in hematological malignancies was still unclear. A systematic review and meta-analysis was performed to comprehensively evaluate the association between serum 25(OH)D levels and prognosis of patients with hematological malignancies. Methods: We searched Pubmed, Embase, Web of Science, and Google Scholar for studies evaluating the association between serum 25(OH)D levels and prognosis of patients with hematological malignancies. The hazard ratios (HR) with 95% confidence intervals (95%CI) for overall survival (OS) or relapse-free survival (RFS) were pooled using meta-analysis. Results: Seven studies with a total of 2,643 patients with hematological cancer were finally included into the meta-analysis. Overall, compared with normal serum 25(OH)D levels, low serum 25(OH)D levels were significantly associated with both poorer OS (HR = 1.85, 95% CI 1.54-2.23, P <0.001) and poorer RFS (HR = 1.45, 95% CI 1.25 to 1.70, P <0.001) in hematological malignancies. Subgroup analysis further showed that low serum 25(OH)D levels were significantly associated with poorer OS and RFS in both lymphoma and leukemia. Conclusion: Low serum 25(OH)D levels are significantly associated with poorer prognosis in patients with hematological malignancies including lymphoma and leukemia. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
27. An Improved BeiDou-2 Satellite-Induced Code Bias Estimation Method.
- Author
-
Fu, Jingyang, Li, Guangyun, and Wang, Li
- Subjects
- *
GLOBAL Positioning System , *MULTIPATH channels , *LINEAR systems , *PERFORMANCE evaluation , *NATURAL satellites - Abstract
Different from GPS, GLONASS, GALILEO and BeiDou-3, it is confirmed that the code multipath bias (CMB), which originate from the satellite end and can be over 1 m, are commonly found in the code observations of BeiDou-2 (BDS) IGSO and MEO satellites. In order to mitigate their adverse effects on absolute precise applications which use the code measurements, we propose in this paper an improved correction model to estimate the CMB. Different from the traditional model which considering the correction values are orbit-type dependent (estimating two sets of values for IGSO and MEO, respectively) and modeling the CMB as a piecewise linear function with a elevation node separation of 10°, we estimate the corrections for each BDS IGSO + MEO satellite on one hand, and a denser elevation node separation of 5° is used to model the CMB variations on the other hand. Currently, the institutions such as IGS-MGEX operate over 120 stations which providing the daily BDS observations. These large amounts of data provide adequate support to refine the CMB estimation satellite by satellite in our improved model. One month BDS observations from MGEX are used for assessing the performance of the improved CMB model by means of precise point positioning (PPP). Experimental results show that for the satellites on the same orbit type, obvious differences can be found in the CMB at the same node and frequency. Results show that the new correction model can improve the wide-lane (WL) ambiguity usage rate for WL fractional cycle bias estimation, shorten the WL and narrow-lane (NL) time to first fix (TTFF) in PPP ambiguity resolution (AR) as well as improve the PPP positioning accuracy. With our improved correction model, the usage of WL ambiguity is increased from 94.1% to 96.0%, the WL and NL TTFF of PPP AR is shorten from 10.6 to 9.3 min, 67.9 to 63.3 min, respectively, compared with the traditional correction model. In addition, both the traditional and improved CMB model have a better performance in these aspects compared with the model which does not account for the CMB correction. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.