Path Tracking and Local Obstacle Avoidance for Automated Vehicle Based on Improved Artificial Potential Field

Weihua Li,Yipeng Wang,Junlong Guo,Dianbo Ren,Jianfeng Wang,Shengkai Zhu,Jianping Xiao,Shijuan Chen 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.5

This study proposes an improved artificial potential field (APF) by considering the cooperative control of local obstacle avoidance and path tracking for automated vehicles. We established the path gravitational potential field (GPF) based on the scheduled path (SP), including the lateral and longitudinal GPFs, to enable the automated vehicle to quickly return to the SP and track after obstacle avoidance, while maintaining control of speed for the entire process. To address the local optimal solution problem of the classical APF, we proposed a sub-target-point selection strategy based on the information of obstacles and SP and established the GPF of the sub-target points. Thus, the automated vehicle can avoid obstacles and quickly return to the SP. Furthermore, the relative velocity of the automated vehicle and the obstacle was used to establish the velocity repulsion potential field (RPF), which improved the adaptability of the APF to dynamic obstacles. The simulation results indicate that the improved APF is capable of cooperative control of path tracking and local obstacle avoidance. Code is available at https://github.com/xiaowang617/Improve-APF.

Mangiferin loaded magnetic PCEC microspheres: preparation, characterization and antitumor activity studies in vitro

WenJing Xiao,Jun Hou,Jie Ma,BoTao Yu,JianDong Ren,WeiHua Jin,Juan Wu,DeZhi Zheng,KaiHua Fan 대한약학회 2021 Archives of Pharmacal Research Vol.44 No.8

Mangiferin is a promising effective chemopreventiveagent against various tumors. However, itsclinical use is limited by poor water solubility and lowbioavailability. In this article, mangiferin loaded magneticPCEC microspheres (MG-MS) were designed, characterizedand the antitumor activity of MG-MS was evaluatedin vitro. The magnetic nanoparticles (MNP) were synthesizedvia the high-temperature reaction of ironacetylacetonate in phenyl ether in the presence of oleic acidand oleylamine. Poly (ε-caprolactone)-poly (ethyleneglycol)-poly (ε-caprolactone) (PCL-PEG-PCL, PCEC)copolymers were formed by ring-opening copolymerizationof ε-CL initiated by PEG-diol using Sn(Oct)2 as acatalyst and MG-MS were prepared by solvent diffusionmethod. MNP, PCEC copolymer, and MG-MS werecharacterized by GPC, TEM, XRD, FT-IR, 1H-NMP andMalvern Laser Particle Sizer. Meanwhile, the antiproliferativeactivity in vitro and in vitro release behavior of thismicrospheres were studied in detail. The results indicatethat the obtained magnetic microspheres might have greatpotential as an effective carrier for mangiferin used incancer chemotherapy.

Phosphorus balance in typical rainfield of black soil region in northeast China

Cailian Hao,Weihua Xiao,Yuyan Zhou,Ying Wang 한국지질과학협의회 2019 Geosciences Journal Vol.23 No.4

This research aimed to evaluate the phosphorus balances at field level in black Soil Region in northeast China, which is one of three black soil regions in world and is one of the most important agricultural production regions in China. By using the soil nutrient balance method, the phosphorus balances were calculated for 11 fields representing four tillage practices [Conventional tillage system (TCT), No-tillage with straw covered system (TNT), Reduced tillage system (TRT) and Contour tillage system (TTT)], three vegetation recovery measures [Conventional tillage management (TCT), Vegetation recovery management (VVR) and Bare management (VB)], three land’s slope (3°, 5° and 7°) and three land's length (20 m, 40 m and 60 m). Processes quantified included mineral fertilizer, organic matter and atmospheric deposition (inputs) and harvested products, surface runoff and soil erosion (outputs). Measurements of phosphorus flows were made in the 11 fields and the phosphorous balance of various experiment plots was assessed in a quantified manner in 2013. Moreover, the rainfall, the tillage practices, the flow output and sand output of experiment plots of different slope gradients and lengths and the relations between dissolved phosphorus and particulate phosphorus of 2013 were also analyzed. Results shows that VVR and VB are phosphorus deficiency and the others are phosphorus surplus. Rainfall are the main sources of phosphorus inputs for VVR and VB among the 11 experiment plots, while chemical fertilizers are the main sources for the other 9 zones. Crop harvest and soil erosion are the main outputs of phosphorus in the 11 zones, except in VVR and VB. This research provides support to the farmland nutrient management and the prevention and control of non-point source pollution within the region.

First-Principles Study of the Three Polymorphs of Crystalline 1,1-Diamino-2,2-dinitrotheylene

Qiong Wu,Weihua Zhu,Heming Xiao 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.8

The electronic structure, optical spectra, and thermodynamic properties of the three FOX-7 polymorphs (α, β, and γ) have been studied systematically using density functional theory. The LDA (CA-PZ) and generalized gradient approximation (GGA) (PW91) functions were used to relax the three FOX-7 phases without any constraint. Their density of states and partial density of states were calculated and analyzed. The band gaps for the three phases were calculated and the sequence of their sensitivity was presented. Their absorption coefficients were computed and compared. The thermodynamic functions including enthalpy (H), entropy (S), free energy (G), and heat capacity (Cp) for the three phases were evaluated.

First-Principles Study of the Three Polymorphs of Crystalline 1,1-Diamino-2,2-dinitrotheylene

Wu, Qiong,Zhu, Weihua,Xiao, Heming Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.8

The electronic structure, optical spectra, and thermodynamic properties of the three FOX-7 polymorphs (${\alpha}$, ${\beta}$, and ${\gamma}$) have been studied systematically using density functional theory. The LDA (CA-PZ) and generalized gradient approximation (GGA) (PW91) functions were used to relax the three FOX-7 phases without any constraint. Their density of states and partial density of states were calculated and analyzed. The band gaps for the three phases were calculated and the sequence of their sensitivity was presented. Their absorption coefficients were computed and compared. The thermodynamic functions including enthalpy (H), entropy (S), free energy (G), and heat capacity ($C_p$) for the three phases were evaluated.

The pharmacological role of Ginsenoside Rg3 in liver diseases: A review on molecular mechanisms

Wenhong Wang,Ke Li,Weihua Xiao The Korean Society of Ginseng 2024 Journal of Ginseng Research Vol.48 No.2

Liver diseases are a significant global health burden and are among the most common diseases. Ginssennoside Rg3 (Rg3), which is one of the most abundant ginsenosides, has been found to have significant preventive and therapeutic effects against various types of diseases with minimal side effects. Numerous studies have demonstrated the significant preventive and therapeutic effects of Rg3 on various liver diseases such as viral hepatitis, acute liver injury, nonalcoholic liver diseases (NAFLD), liver fibrosis and hepatocellular carcinoma (HCC). The underlying molecular mechanism behind these effects is attributed to apoptosis, autophagy, antioxidant, anti-inflammatory activities, and the regulation of multiple signaling pathways. This review provides a comprehensive description of the potential molecular mechanisms of Rg3 in the development of liver diseases. The article focuses on the regulation of apoptosis, oxidative stress, autophagy, inflammation, and other related factors. Additionally, the review discusses combination therapy and liver targeting strategy, which can accelerate the translation of Rg3 from bench to bedside. Overall, this article serves as a valuable reference for researchers and clinicians alike.

CAWR: Buffer Replacement with Channel-Aware Write Reordering Mechanism for SSDs

Ronghui Wang,Zhiguang Chen,Nong Xiao,Minxuan Zhang,Weihua Dong 한국전자통신연구원 2015 ETRI Journal Vol.37 No.1

A typical solid-state drive contains several independent channels that can be operated in parallel. To exploit this channel-level parallelism, a variety of works proposed to split consecutive write sequences into small segments and schedule them to different channels. This scheme exploits the parallelism but breaks the spatial locality of write traffic; thus, it is able to significantly degrade the efficiency of garbage collection. This paper proposes a channel-aware write reordering (CAWR) mechanism to schedule write requests to different channels more intelligently. The novel mechanism encapsulates correlated pages into a cluster beforehand. All pages belonging to a cluster are scheduled to the same channels to exploit spatial locality, while different clusters are scheduled to different channels to exploit the parallelism. As CAWR covers both garbage collection and I/O performance, it outperforms existing schemes significantly. Trace-driven simulation results demonstrate that the CAWR mechanism reduces the average response time by 26% on average and decreases the valid page copies by 10% on average, while achieving a similar hit ratio to that of existing mechanisms.

A Three-Dimensional Deep Convolutional Neural Network for Automatic Segmentation and Diameter Measurement of Type B Aortic Dissection

Yu Yitong,Gao Yang,Wei Jianyong,Liao Fangzhou,Xiao Qianjiang,Zhang Jie,Yin Weihua,Lu Bin 대한영상의학회 2021 Korean Journal of Radiology Vol.22 No.2

Objective: To provide an automatic method for segmentation and diameter measurement of type B aortic dissection (TBAD). Materials and Methods: Aortic computed tomography angiographic images from 139 patients with TBAD were consecutively collected. We implemented a deep learning method based on a three-dimensional (3D) deep convolutional neural (CNN) network, which realizes automatic segmentation and measurement of the entire aorta (EA), true lumen (TL), and false lumen (FL). The accuracy, stability, and measurement time were compared between deep learning and manual methods. The intra- and inter-observer reproducibility of the manual method was also evaluated. Results: The mean dice coefficient scores were 0.958, 0.961, and 0.932 for EA, TL, and FL, respectively. There was a linear relationship between the reference standard and measurement by the manual and deep learning method (r = 0.964 and 0.991, respectively). The average measurement error of the deep learning method was less than that of the manual method (EA, 1.64% vs. 4.13%; TL, 2.46% vs. 11.67%; FL, 2.50% vs. 8.02%). Bland-Altman plots revealed that the deviations of the diameters between the deep learning method and the reference standard were -0.042 mm (-3.412 to 3.330 mm), -0.376 mm (-3.328 to 2.577 mm), and 0.026 mm (-3.040 to 3.092 mm) for EA, TL, and FL, respectively. For the manual method, the corresponding deviations were -0.166 mm (-1.419 to 1.086 mm), -0.050 mm (-0.970 to 1.070 mm), and -0.085 mm (-1.010 to 0.084 mm). Intra- and inter-observer differences were found in measurements with the manual method, but not with the deep learning method. The measurement time with the deep learning method was markedly shorter than with the manual method (21.7 ± 1.1 vs. 82.5 ± 16.1 minutes, p < 0.001). Conclusion: The performance of efficient segmentation and diameter measurement of TBADs based on the 3D deep CNN was both accurate and stable. This method is promising for evaluating aortic morphology automatically and alleviating the workload of radiologists in the near future.