An Brain Image Segmentation Method based on Non-local MRF

Zhongyuan Cui,Feng Wang,Jin Wang 보안공학연구지원센터 2014 International Journal of Signal Processing, Image Vol.7 No.5

Brain image segmentation is one of the most important parts of clinical diagnostic tools. However, accurate segmentation of brain images is a very difficult task due to the noise, inhomogeneity and sometimes deviation in brain images. Wells model incorporates the brain image segmentation and inhomogeneity correction into one framework to overcome influences from the intensity inhomogeneity and obtain good segmentation performance. However, the classical Wells model did not take spatial information into account, so its segmentation results are sensitive to the noise. In order to overcome this limitation, the MRF theory and the nonlocal information are used to construct a nonlocal Markov Random Field. With this nonlocal MRF, the improved Wells method can obtain much better segmentation results. The experimental results show that our method is robust to the noise and is able to simultaneously keep the image edge and slender topological structure very well.

Gliding Trajectory Programming of Guided Projectile Based on Improved L1 Penalty Successive Convex Programming Algorithm

Qinghai Wang,Qi Chen,Zhongyuan Wang 제어로봇시스템학회 2021 제어로봇시스템학회 국제학술대회 논문집 Vol.2021 No.10

Taking the general control energy optimal trajectory programming model as the research object, the Radau pseudo-spectral method is used to discretize the continuous variables and then linearly convexify the nonlinear dynamic equation to establish the standard convex optimization model. In order to solve the problems of large amount of redundant computation and slow convergence speed of the traditional L1 penalty successive convex programming algorithm (LPSCP), an improved L1 penalty successive convex programming algorithm (ILPSCP) is proposed in this paper. The algorithm introduces the feasibility judgment process to avoid solving the more complex L1 subproblem PL1 when the original problem P0 is feasible. Taking the gliding trajectory model of the guided projectile in the longitudinal plane as an example, the traditional LPSCP algorithm, the ILPSCP algorithm proposed in this paper and GPOPS2 are used to simulate and compare. The simulation results of ILPSCP algorithm are highly consistent with those of GPOPS2, which proves the effectiveness of the proposed ILPSCP algorithm for solving trajectory programming problems, and the convergence rate of ILPSCP algorithm is improved by 46.36% compared with traditional LPSCP algorithm.

Regulation of precursor solution concentration for In-Zn oxide thin film transistors

Zhongyuan He,Yanping Chen,Yaogang Li,Qinghong Zhang,Chengyi Hou,Hongzhi Wang 한국물리학회 2018 Current Applied Physics Vol.18 No.11

The tunable electronic performance of the solution-processed semiconductor metal oxide is of great significance for the printing electronics. In current work, transparent thin-film transistors (TFTs) with indium-zinc oxide (IZO) were fabricated as active layer by a simple eco-friendly aqueous route. The aqueous precursor solution is composed of water without any other organic additives and the IZO films are amorphous revealed by the X-ray diffraction (XRD). With systematic studies of atomic force microscopy (AFM), X-ray photoemission spectroscopy (XPS) and the semiconductor property characterizations, it was revealed that the electrical performance of the IZO TFTs is dependent on the concentration of precursor solution. As well, the optimum preparation process was obtained. The concentrations induced the regulation of the electronic performance was clearly demonstrated with a proposed mechanism. The results are expected to be beneficial for development of solution-processed metal oxide TFTs.

The inflammation regulation effects of Enterococcus faecium HDRsEf1 on human enterocyte-like HT-29 cells

Zhongyuan Tian,Lu Yang,Penghui Li,Yuncai Xiao,Jian Peng,Xiliang Wang,Zili Li,Mei Liu,Dingren Bi,Deshi Shi 한국통합생물학회 2016 Animal cells and systems Vol.20 No.2

Enterococcus faecium HDRsEf1 strain used as a probiotic to inhibit intestine inflammation and improve animal growth performance has been proved by our research team; however, it remains unclear how HDRsEf1 was recognized by intestine cells and how it activates the downstream pathway which benefit intestine health. In this study, HDRsEf1 was used to stimulate HT-29 cell line to partially uncover the intestine benefit mechanism of HDRsEf1. The results of cell viability assays showed that HDRsEf1 had no toxicity on HT-29 at concentrations up to 1 × 108 CFU/mL, HDRsEf1 could upregulate the TLR1, TLR2, and TLR6 mRNA level, especially TLR2, and significantly downregulate the mRNA level of TLR4, TLR5, TLR7, TLR8, but did not significantly affect the mRNA or protein level of MyD88, which suggests that HDRsEf1 activates the TLR2 pathway in an MyD88-independent pattern. HDRsEf1 could significantly downregulate the mRNA level of pro-inflammatory factors IL-1β, IL-6, IL-8, IL-12p35, IL-17, and TNF-α and did not affect the anti-inflammatory factors IL-10, PPAR-γ, and TSLP; besides HDRsEf1 did not upregulate the degradation of IκB in HT-29 cells. By contrast, enterohemorrhagic E. coli (EHEC) O157:H7 strongly up-regulated the mRNA level of pro-inflammatory factors IL-1β, IL-6, IL-8, IL-23, and TNF-α, downregulated obviously anti-inflammatory factor PPAR-ɣ, and obviously upregulated the degradation of IκB, which suggested that HDRsEf1 may act as an antagonist to regulate intestine inflammation response to intestine pathogen. These findings shed a light on the intestine benefit mechanism of HDRsEf1.

Reverse Salient Pole Design of Interior Pole-changing Permanent Magnet Synchronous Motor

Huimin Wang,Zhongyuan Hao,Xiangyi Li,Guokai Jiang,Liyan Guo 한국자기학회 2024 Journal of Magnetics Vol.29 No.1

In order to prevent the demagnetization of low coercivity permanent magnets, the pole-changing permanent magnet synchronous motor usually adopts I<SUB>d</SUB>=0 control strategy, which has the problems that the reluctance torque of the motor cannot be utilized and the torque density is low. In order to solve this problem, a new type of rotor reverse salient pole structure of pole-changing permanent magnet synchronous motor is proposed in this paper. Based on the comparative analysis of the magnetic field distribution characteristics of the motor under different pole numbers, the common d-axis and q-axis magnetic path under 8-pole and 4-pole are planned, and then the winding inductance L<SUB>d</SUB>>L<SUB>q</SUB> under two pole numbers is realized by setting bar and arcmagnetic barriers and non-uniform reduction of air gap length. On this basis, the Taguchi method is used to set the parameters of the proposed structure, and the motor torque ripple is reduced under the premise of increasing the motor torque amplitude as much as possible under the 8-pole and 4-pole, and the optimal parameter combination of the proposed structure is determined. Through the FEA, it is verified that the motor can produce the maximum torque at the negative current angle before and after the pole change, so as to effectively utilize the reluctance torque, avoid the permanent magnet demagnetization and improve the torque density.

Trace surface fluorination and tungsten-intercalation cooperated dual modification induced photo-activity enhancement of titanium dioxide

Yifan Xu,Zhongyuan Liu,Kunlun Wang,Chunyao Niu,Pengfei Yuan,Jin You Zheng,Young Soo Kang,Xiao Li Zhang 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.108 No.-

General modification that utilizes insoluble tungstic acid or highly toxic hydrofluoric acid to improvecharge separation and transfer in TiO2 results in considerable issues such as uneven doping, significantimpacts on particle size and morphology, as well as environmental hazards. In the present work, an environmentalbenign one-pot dual-modification approach was demonstrated that uses soluble sodium tungstateand only trace-level sodium fluoride as replacements. The photoactivity efficiency for decolorationof methylene blue (MB) solution was improved by 33.6% and 119.5% under ultraviolet and visible light,respectively. Meanwhile, the photocurrent density reached an enhancement by 181.2% by this dualmodification. The dual-modification had negligible influence on the crystal structure and the surface areaof the TiO2 nanoparticles. Density functional calculation suggested the remarkable improvements of thephotocatalysis of TiO2 can be ascribed to the rapid charge separation and transfer owing to the downshiftof conduction band from the tungsten doping and localized spatial charge separation from the surfacefluorination enabled by the dual-modification approach.

Energy-Optimal Waypoint-Following Guidance for Gliding-Guided Projectiles

Qiulin Yin,Qi Chen,Zhongyuan Wang 제어로봇시스템학회 2021 제어로봇시스템학회 국제학술대회 논문집 Vol.2021 No.10

This paper addresses the problem of energy-optimal way-point-following guidance for Long-Range Gliding-Guided projectiles with the consideration of velocity variation. This proposed guidance law is derived as a solution of a linearized kinematics model. The algorithm integrates path planning and following into a single step and can be applied to a general waypoint-following mission. Nonlinear numerical simulations clearly demonstrate the effectiveness and superiority of the proposed formulations.

Consensus-Based Finite-Time Cooperative Guidance with Field-of-View Constraint

Shuai Ma,Xugang Wang,Zhongyuan Wang,Qi Chen 한국항공우주학회 2022 International Journal of Aeronautical and Space Sc Vol.23 No.5

The problem of cooperative guidance of multiple missiles with field-of-view constraint is addressed based on consensus theory. Considering the singularity problem when the second-order consensus algorithm is directly applied to missile guidance, a novel finite-time consensus algorithm with field-of-view constraint is derived and proved. The singularity problem is also avoided. Cooperative guidance law under 2D and 3D engagement is designed using a two-stage guidance scheme. In the first stage, a decentralized guidance law is designed based on the derived finite-time consensus algorithm to provide the latter stage’s desired initial conditions, and proportional navigation guidance law is used in the second stage. The proposed cooperative guidance law requires neither time-to-go estimation nor controllable velocity magnitude. Compared with other two-stage guidance schemes, the proposed cooperative guidance law can provide better initial conditions for the second stage. Numerical simulation and comparison work demonstrate the effectiveness and superiority of the proposed cooperative guidance law.

DGE analysis of changes in gene expression in response to temperature and deltamethrin stress in the silkworm (Bombyx mori)

Xu-Dong TANG,Nan LIU,Wei Wang,Jieyun Yan,Li Xu,Zhongyuan Shen 한국응용곤충학회 2016 Journal of Asia-Pacific Entomology Vol.19 No.1

The silkworm (Bombyx mori) is an important insect for various industrial applications and is also a model insect for the order Lepidoptera. The silkworm is more resistant to deltamethrin at high temperatures than at low temperatures. To elucidate the role of the negative temperature coefficient of deltamethrin in the silkworm, digital gene expression (DGE) analysis was performed for the identification of differentially expressed genes in silkworms challenged with deltamethrin at different temperatures. Compared with deltamethrin exposure at 30 °C, silkworms treated at 20 °C exhibited more severe stress responses, and gene sets associated with peptidoglycan recognition protein (PGRP),mucin, and antimicrobial peptides (AMPs)were downregulated dramatically. Similarly, a decrease in genes related to reactive oxygen species scavenging was also detected, which may have resulted in an imbalance between radical-generating and radical-scavenging systems. These results indicated that the lower mortality rate after deltamethrin treatment at high temperature was caused by a series of gene alterations (quantitative increases) rather than qualitative changes.