Adaptive Nonsingular Fast Terminal Sliding Mode Guidance Law with Impact Angle Constraints

Shen-Min Song,Junhong Song,Huibo Zhou 제어·로봇·시스템학회 2016 International Journal of Control, Automation, and Vol.14 No.1

This paper considers the terminal guidance problem of missiles intercepting maneuvering targets withimpact angle constraints. Based on an advanced nonsingular fast terminal sliding mode control scheme and adaptivecontrol, an adaptive nonsingular fast terminal sliding mode guidance law is proposed in the presence of the targetacceleration as an unknown bounded external disturbance. In the design procedure, an adaptive law is presentedto estimate the unknown upper bound of the external disturbance. Theoretical analysis shows that the proposedguidance law can guarantee the finite-time convergence in both the reaching phase and the sliding phase by applyinga Lyapunov-based approach. Numerical simulations are presented to demonstrate the effectiveness of the proposedguidance law. Although the proposed guidance law is developed for the constant speed missiles, by the extensivenumerical simulations with a realistic missile model, the performance is shown to be equally good for the varyingspeed missiles.

Rock bridge fracture model and stability analysis of surrounding rock in underground cavern group

Song Yu,Wei-shen Zhu,Wei-min Yang,Dun-fu Zhang,Qing-song Ma 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.3

Many hydropower stations in southwest China are located in regions of brittle rock mass with high geo-stresses. Under these conditions deep fractured zones often occur in the sidewalls of the underground caverns of a power station. The theory and methods of fracture and damage mechanics are therefore adopted to study the phenomena. First a flexibility matrix is developed to describe initial geometric imperfections of a jointed rock mass. This model takes into account the area and orientation of the fracturedsurfaces of multiple joint sets, as well as spacing and density of joints. Using the assumption of the equivalent strain principle, a damage constitutive model is established based on the brittle fracture criterion. In addition the theory of fracture mechanics is applied to analyze the occurrence of secondary cracks duringa cavern excavation. The failure criterion, for rock bridge coalescence and the damage evolution equation, has been derived and a new sub-program integrated into the FLAC-3D software. The model has then beenapplied to the stability analysis of an underground cavern group of a hydropower station in Sichuan province, China. The results of this method are compared with those obtained by using a conventional elasto-plastic model and splitting depth calculated by the splitting failure criterion proposed in a previous study. The results are also compared with the depth of the relaxation and fracture zone in the surrounding rock measured by field monitoring. The distribution of the splitting zone obtained both by the proposed model and by the field monitoring measurements are consistent to the validity of the theory developed herein.

Functional Roles of Exosomes in Allergic Contact Dermatitis

Song Bocui,Chen Qian,Li Yuqi,Zhan Shuang,Zhao Rui,Shen Xue,Liu Min,Tong Chunyu 한국미생물·생명공학회 2022 Journal of microbiology and biotechnology Vol.32 No.12

Allergic contact dermatitis (ACD) is an allergen-specific T-cell-mediated inflammatory response, albeit with unclear pathogenesis. Exosomes are nanoscale extracellular vesicles secreted by several cell types and widely distributed in various biological fluids. Exosomes affect the occurrence and development of ACD through immunoregulation among other ways. Nevertheless, the role of exosomes in ACD warrants further clarification. This review examines the progress of research into exosomes and their involvement in the pathogenesis, diagnosis, and treatment of ACD and provides ideas for exploring new diagnostic and treatment methods for this disease.

Rock bridge fracture model and stability analysis of surrounding rock in underground cavern group

Yu, Song,Zhu, Wei-Shen,Yang, Wei-Min,Zhang, Dun-Fu,Ma, Qing-Song Techno-Press 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.3

Many hydropower stations in southwest China are located in regions of brittle rock mass with high geo-stresses. Under these conditions deep fractured zones often occur in the sidewalls of the underground caverns of a power station. The theory and methods of fracture and damage mechanics are therefore adopted to study the phenomena. First a flexibility matrix is developed to describe initial geometric imperfections of a jointed rock mass. This model takes into account the area and orientation of the fractured surfaces of multiple joint sets, as well as spacing and density of joints. Using the assumption of the equivalent strain principle, a damage constitutive model is established based on the brittle fracture criterion. In addition the theory of fracture mechanics is applied to analyze the occurrence of secondary cracks during a cavern excavation. The failure criterion, for rock bridge coalescence and the damage evolution equation, has been derived and a new sub-program integrated into the FLAC-3D software. The model has then been applied to the stability analysis of an underground cavern group of a hydropower station in Sichuan province, China. The results of this method are compared with those obtained by using a conventional elasto-plastic model and splitting depth calculated by the splitting failure criterion proposed in a previous study. The results are also compared with the depth of the relaxation and fracture zone in the surrounding rock measured by field monitoring. The distribution of the splitting zone obtained both by the proposed model and by the field monitoring measurements are consistent to the validity of the theory developed herein.

Targeting Orthotopic Glioma in Mice with Genetically Engineered Salmonella typhimurium

Wen, Min,Jung, Shin,Moon, Kyung-Sub,Jiang, Shen Nan,Li, Song-Yuan,Min, Jung-Joon The Korean Neurosurgical Society 2014 Journal of Korean neurosurgical society Vol.55 No.3

Objective : With the growing interests of bacteria as a targeting vector for cancer treatment, diverse genetically engineered Salmonella has been reported to be capable of targeting primary or metastatic tumor regions after intravenous injection into mouse tumor models. The purpose of this study was to investigate the capability of the genetically engineered Salmonella typhimurium (S. typhimurium) to access the glioma xenograft, which was monitored in mouse brain tumor models using optical bioluminescence imaging technique. Methods : U87 malignant glioma cells (U87-MG) stably transfected with firefly luciferase (Fluc) were implanted into BALB/cAnN nude mice by stereotactic injection into the striatum. After tumor formation, attenuated S. typhimurium expressing bacterial luciferase (Lux) was injected into the tail vein. Bioluminescence signals from transfected cells or bacteria were monitored using a cooled charge-coupled device camera to identify the tumor location or to trace the bacterial migration. Immunofluorescence staining was also performed in frozen sections of mouse glioma xenograft. Results : The injected S. typhimurium exclusively localized in the glioma xenograft region of U87-MG-bearing mouse. Immunofluorescence staining also demonstrated the accumulation of S. typhimurium in the brain tumors. Conclusion : The present study demonstrated that S. typhimurium can target glioma xenograft, and may provide a potentially therapeutic probe for glioma.

Noise Interpolation of MOSFET in Moderate Inversion and Its Verification in Low Noise Amplifier

송익현(Ickhyun Song),구민석(Min Suk Koo),정학철(Hakchul Jung),이상훈(Sanghoon Lee),Shen Yehao,전희석(Hee Sauk Jhon),신형철(Hyungcheol Shin) 대한전자공학회 2007 대한전자공학회 학술대회 Vol.2007 No.11

MOSFET noise in moderate inversion region is interpolated using two noise models in the regions of subthreshold and strong inversion. With these channel noise value, a CMOS low noise amplifier (LNA) operating in moderate inversion region is designed for verification and its noise characteristic is presented.

Quaternion-based Finite-time Control for Attitude Tracking of the Spacecraft without Unwinding

Yong Guo,Shen-Min Song,Xue-Hui Li 제어·로봇·시스템학회 2015 International Journal of Control, Automation, and Vol.13 No.6

This paper investigates two finite-time controllers for the attitude tracking control of the spacecraft based on the quaternion by terminal sliding mode control. Because quaternion is unable to represent the set of attitudes both globally and uniquely, it can result in unwinding. Unwinding makes a spacecraft perform an unnecessary large-angle maneuver when a small-angle maneuver in the opposite rotational direction is sufficient to achieve the objective. The first controller converges to the equilibrium without singularity in finite time, while the second one converges to the region near the equilibrium without singularity, chattering and unwinding in finite time. Saturation function is introduced to the first controller to eliminate singularity, while a novel fast terminal sliding mode control is introduced to the second controller to eliminate singularity and unwinding. Theoretical analysis shows that the controllers can make the spacecraft follow a time-varying reference attitude signal in finite time and guarantee the stability of the overall closed-loop system. Numerical simulations also demonstrate the effectiveness of the proposed control schemes.

Synthesis of TiO2/rGO Nanocomposites with Enhanced Photoelectrochemical Performance and Photocatalytic Activity

Dewang Kong,Min Zhao,Shikuo Li,Fangzhi Huang,Jiming Song,Yupeng Yuan,YUHUA SHEN,ANJIAN XIE 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.1

In this paper, a facile and efficient method combined sol–gel method with hydrothermal process was employed for preparing titanium dioxide (TiO2/reduced graphene oxide (rGO) nanocomposites without using any reductants or surfactants. This approach leads to the reduction of graphene oxide (GO) and the growth of TiO2 nanorods simultaneously. The results reveal that the TiO2 short nanorods with average size of 15 nm in length and 10 nm in diameter were uniformly grown on the rGO sheets with high dispersion. Compared with the pure TiO2 nanoparticles, the TiO2/rGO composites exhibit strong absorption in the visible light range. The photocurrent density of nanocomposites reached 0.826 mA/cm2 under the simulated sunlight illumination, which is 3.5 times than that of pure TiO2. An enhancement of photocatalytic hydrogen formation rate for the water splitting was observed over the TiO2/rGO composite photocatalysts, the fastest formation rate can reach 889.28 µmol·g-1·h-1 when TiO2 coupling with 1wt.% rGO. Also the hydrogen production rate is about 3.27 times larger than pure TiO2 and 2.23 times than P25 due to the excellent electron trapping and transportation properties of rGO and the synergistic effect between TiO2 and rGO.

Adaptive Dynamic Surface Control for Spacecraft Terminal Safe Approach with Input Saturation Based on Tracking Differentiator

Guan-Qun Wu,Shen-Min Song,Jing-Guang Sun 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.3

This thesis studies the spacecraft terminal safe approach control problem considering input saturation. Based on the spacecraft relative motion model and sphere collision avoidance potential function, an anti-saturation controller and an adaptive finite-time anti-saturation controller using dynamic surface control(DSC) are presented for the situations of known and unknown upper bound of external disturbances respectively, which can guarantee that no collisions happen in the tracking process. The second-order tracking differentiator is introduced to design the controllers, which avoids the differential of the virtual control signal and ensures the tracking performance of system output signals. Meanwhile, the auxiliary system is introduced to handle input saturation. Lyapunov stability theory is adopted to prove that the states of system under the designed controllers are uniformly ultimately bounded and practical finite-time stable respectively, and the chaser spacecraft can approach to the desired position without collision. The numerical simulation results demonstrate that the chaser spacecraft using the designed controllers can realize terminal safe approach to target spacecraft, which further illustrate the effectiveness of the proposed controllers.

The Role of K _V 7.3 in Regulating Osteoblast Maturation and Mineralization

Yang, Ji Eun,Song, Min Seok,Shen, Yiming,Ryu, Pan Dong,Lee, So Yeong MDPI 2016 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.17 No.3

<P>KCNQ (K<SUB>V</SUB>7) channels are voltage-gated potassium (K<SUB>V</SUB>) channels, and the function of K<SUB>V</SUB>7 channels in muscles, neurons, and sensory cells is well established. We confirmed that overall blockade of K<SUB>V</SUB> channels with tetraethylammonium augmented the mineralization of bone-marrow-derived human mesenchymal stem cells during osteogenic differentiation, and we determined that K<SUB>V</SUB>7.3 was expressed in MG-63 and Saos-2 cells at the mRNA and protein levels. In addition, functional K<SUB>V</SUB>7 currents were detected in MG-63 cells. Inhibition of K<SUB>V</SUB>7.3 by linopirdine or XE991 increased the matrix mineralization during osteoblast differentiation. This was confirmed by alkaline phosphatase, osteocalcin, and osterix in MG-63 cells, whereas the expression of Runx2 showed no significant change. The extracellular glutamate secreted by osteoblasts was also measured to investigate its effect on MG-63 osteoblast differentiation. Blockade of K<SUB>V</SUB>7.3 promoted the release of glutamate via the phosphorylation of extracellular signal-regulated kinase 1/2-mediated upregulation of synapsin, and induced the deposition of type 1 collagen. However, activation of K<SUB>V</SUB>7.3 by flupirtine did not produce notable changes in matrix mineralization during osteoblast differentiation. These results suggest that K<SUB>V</SUB>7.3 could be a novel regulator in osteoblast differentiation.</P>