Control Analysis for a Non-minimum Phase Static Unstably Missile

FAN Jun-fang,CHEN Ying,LIN Peng 제어로봇시스템학회 2014 제어로봇시스템학회 국제학술대회 논문집 Vol.2014 No.10

A novel control evaluation approach for tactical missile is detailed. The characteristics of non-minimum phase and static instability of a tail-controlled tactical missile are presented firstly. Then the frequency-domain controllable analysis is derived. Due to the limitations of traditional stability margins, the vector margin (VM) is introduced and compared with sensitivity function to show their essential relationship. A longitudinal three-loop autopilot is designed to stabilize the non-minimum phase static unstably missile dynamics and used as the baseline for all the tan available linear autopilot topologies given with the identical closed-loop characteristic equation and time-domain step response. Then vector margin method is adopted to compute and evaluate the stability of all available autopilots. The analysis and computation results show that the vector margin method could give better evaluation on system stability.

Impact-Angle-Constraint Look Angle Guidance for Miniature Missile

FAN Jun-fang,WANG Gang,CHEN Ying,DONG Si-yu 제어로봇시스템학회 2016 제어로봇시스템학회 국제학술대회 논문집 Vol.2016 No.10

An engagement dynamic model is set up for the miniature missile guidance solution under the constraints of field-of-view angle and terminal impact angle. The impact-angle constraint guidance law design is converted into an optimal control problem subjected to terminal constraints. Then a look angle guidance solution without line-of-sight rate is detailed to satisfy the requirement on field-of-view and impact angles. The relation between the required maximal look angle and the terminal impact angle is analyzed and formulated. The proposed method is simulated and validated. The results show that a miniature missile could intercept a stationary target with the required impact angle.

Control Capability

FAN Jun-fang,An Xiao-qian 제어로봇시스템학회 2015 제어로봇시스템학회 국제학술대회 논문집 Vol.2015 No.10

The essential control characteristics for a two and three-loop acceleration autopilot of tactical missile were presented from a frequency analysis perspective. The basic limitation of right-half-phase pole and zero from airframe aerodynamics was analyzed using an open-loop crossover frequency inequality, which showed a consistent conclusion with the final overall stability condition in nature. To reveal the feedback control capability, the rate feedback, rate plus attitude feedback, and linear acceleration feedback, were calculated and simplified based on engineering requirement, respectively. Then an equivalent actuator dynamics were introduced to compute the stability condition at high frequency. Such that the global stability condition was obtained in explicit formulation. The results showed that the autopilot control capability is dominated by actuator bandwidth, and a compromise should be determined between the flight performance and the actuator requirement for a statically instable missile.

A Hybrid Differentiator for Strapdown Guidance System

Fan Jun-fang,SU Zhong,LI Qing,Wang Jiang 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10

A strapdown guidance system for low-cost precise guided munitions is presented using strapdown small field-of-view (FOV) seeker and miniature inertial measurement unit (MIMU). The three-dimension line-of-sight (LOS) dynamics are described using the missile-target geometric transformation. Due to the weakness of strapdown seeker, a hybrid differentiator is then introduced to obtain and filter the inertial LOS rate for proportional guidance law. The analysis and trajectory simulation results verify the performance of the proposed algorithm.

Synthesis and Application of Phosphorus-containing Flame Retardant Plasticizer for Polyvinyl Chloride

Fang Wang,Siyu Pan,Peikun Zhang,Haojun Fan,Yi Chen,Jun Yan 한국섬유공학회 2018 Fibers and polymers Vol.19 No.5

A novel phosphorus-containing flame retardant plasticizer (PFRP) derived from castor oil acid methyl ester (COME) was synthesized to substitute dioctyl phthalate (DOP) for plasticizing polyvinyl chloride (PVC) products. The chemical structures of PFRP were confirmed by fourier transform infrared spectroscopy (FTIR) and 1H nuclear magnetic resonance (1H NMR). Meanwhile, the plasticizing effect, flammability and thermal stability of plasticized PVC films were investigated by dynamic mechanical analyzer (DMA), limiting oxygen index (LOI) test, scanning electron microscope (SEM) and thermogravimetric analysis (TGA). As the PFRP content increasing from 0 wt% to 50 wt% amount of plasticizers, the plasticizing efficiency and the mechanical properties showed a slightly decreasing tendency compared with that of DOP, while the LOI value of plasticized PVC increased remarkably from 21.5 % to 25.2 %, showing a combined plasticizing efficiency and flame retardancy. SEM and TGA analysis indicated that PFRP had little effect on thermal stability but was effective to promote the formation of compact carbon residue.

Double magnetic entropy change peaks and high refrigerant capacity in Gd1- xHoxNi compounds in the melt-spun form

Jun-fan Jiang,Hao Ying,Tang-fu Feng,Ren-bing Sun,Xie Li,Fang Wang 한국물리학회 2018 Current Applied Physics Vol.18 No.12

Gd1-xHoxNi melt-spun ribbons were fabricated by a single-roller melt spinning method. All the compounds crystallize in an orthorhombic CrB-type structure. The Curie temperature (TC) was tuned between 46 and 99 K by varying the concentration of Gd and Ho. A spin reorientation (SRO) transition is observed around 13 K. Different from TC, the SRO transition temperature is almost invariable for all compounds. Two peaks of magnetic entropy change (ΔSM) were found. One at the higher temperature range was originated from the paramagnet-ferromagnet phase transition and the other at the lower temperature range was caused by the SRO transition. The maximum of ΔSM around TC is almost same. The other maximum of ΔSM around SRO transition, however, had significantly positive relationship with x. It reached a maximum about 8.2 J kg−1 K−1 for x=0.8. Thus double large ΔSM peaks were obtained in Gd1-xHoxNi melt-spun ribbons with the high Ho concentration. And the refrigerant capacity power reached a maximum of 622 J kg−1 for x=0.6. Gd1-xHoxNi ribbons could be good candidate for magnetic refrigerant working in the low temperature especially near the liquid nitrogen temperature range.

The Beneficial Effects of a Polysaccharide from Moringa oleifera Leaf on Gut Microecology in Mice

Fang Wang,Yi-Fan Bao,Jia-Jun Si,Yu Duan,Ze-Bin Weng,Xin-Chun Shen 한국식품영양과학회 2019 Journal of medicinal food Vol.22 No.9

Moringa oleifera is a natural plant with high nutritional and pharmacological value. Leaves of M. oleifera contain a variety of active substances. In our previous research, we had obtained a polysaccharide separated from M. oleifera leaf, namely MOs-2-a (1.35 × 104 Da). In this study, this polysaccharide was administrated daily to 6 week-old ICR mice for 4 weeks. Then, the body weight, immunity, intestinal digestion, and intestinal microenvironment of Institute of Cancer Research (ICR) mice were investigated. After 4 weeks of feeding intervention with the polysaccharide, the immune and intestinal digestive ability of the ICR mice were significant as shown by the organ index, digestive enzymes, and reduction of serum tumor necrosis factor-alpha and diamine oxidase levels. The polysaccharide could regulate the microbial composition of the intestinal tract in mice by increasing the bacteria that have been reported for antiobesity effects, short chain fatty acid production, and lactic acid production. These findings indicate that the polysaccharide of M. oleifera leaf might be a promising prebiotic that exhibits health promotion effects.

Genetic variation and population structure of the oriental fruit moth Grapholita molesta in Shanxi, a major pome fruits growing region in North China

Jing Yang,Zhong-Fang Liu,Ji-Qiao Fan,Yu-PengWu,Rui-Yan Ma,Ren-Jun Fan 한국응용곤충학회 2016 Journal of Asia-Pacific Entomology Vol.19 No.4

Grapholitamolesta, commonly known as the oriental fruit moth, is one of the most destructive fruit pests both in China and in other regions of the world. We examined the genetic diversity and population structures of G. molesta populations from 11 locations in a major pome fruit production region (Shanxi province) in North China using seven microsatellite markers and sequence variations in two mitochondrial genes. We found that G.molesta in the studied region exhibited high levels of genetic diversity. Among 271 individual insects examined using microsatellite markers, mean number of alleles ranged from 5.86 to 9.00 with average 8.01. Population structure analysis revealed that populations from the eleven sampling sites formed two clusters without apparent distance isolation. Cluster 1 consisted of eight populations distributed in five regions of the sampling sites, whereas Cluster 2 consisted of three populations distributed in two distant locations of the sampling sites. Genetic exchange analysis revealed that about half of the haplotypes were shared among over 90% individual insects from different regions. Our results indicated that the population structure and genetic exchange of G. molesta in the studied region might have been affected by limited dispersal ability of the insect, environmental condition, colonization history and human-mediated dispersal. These findings should provide useful information for the implementation of area-wide pest management and for further characterization of genetic variation and population structure of this economically important pest.

The Association of GSDMB and ORMDL3 Gene Polymorphisms With Asthma: A Meta-Analysis

Chun-Ni Zhao,Ye Fan,Jian-Jun Huang,Hai-Xia Zhang,Tao Gao,Cong Wang,Tong Wang,Li-Fang Hou 대한천식알레르기학회 2015 Allergy, Asthma & Immunology Research Vol.7 No.2

Purpose: ORM1-like 3 (ORMDL3) belongs to a highly conserved protein family which is anchored as transmembrane protein in the endoplasmic reticulum. Gasdermin B (GSDMB) is adjacent to ORMDL3 on chromosome 17q21.2 and belongs to the gasdermin-domain containing the protein family(GSDM family). Recent reports suggest that GSDMB and ORMDL3 are associated with asthma in several populations. However, genetic associationstudies that examined the association of GSDMB and ORMDL3 gene variants with asthma showed conflicting results. To assess whether combinedevidence shows the association between GSDMB/ORMDL3 polymorphism and asthma. Methods: A bibliographic search from MEDLINE identified13 original articles using the search keywords ‘GSDMB’, ‘ORMDL3’, and ‘asthma’. An updated literature-based meta-analysis involving 6,691 subjectswith asthma, 9,281 control individuals, and 1,360 families were conducted. Meta-odds ratios (ORs) and 95% confidence intervals (CIs) basedon the fixed effects model or the random effects model depended on Cochran’s Q-statistic and I2 values. Data from case-control and TDT studieswere analyzed in an allelic model using the Catmap software. Results: We selected and identified 3 SNPs of ORMDL3 associated with asthma(rs8076131: OR=1.10; 95% CI, 1.02-1.20; P=0.012. rs12603332: OR=1.15; 95% CI, 1.05-1.25; P=0.002. rs3744246: OR=1.10; 95% CI, 1.02-1.17;P=0.008) and 1 SNP of GSDMB associated with asthma (rs7216389: OR=1.37; 95% CI, 1.27-1.47; P<0.01). Publication bias was estimated usingmodified Egger’s linear regression test proposed by Harbordetal and revealed no evidence of biases. Furthermore, cumulative meta-analysis in chronologicalorder showed the inclination toward significant association for rs7216389 and rs12603332 with continually adding studies, and the inclinationtoward null-significant association for rs3744246 and rs8076131. Conclusions: Moderate evidence exists for associations of the ORMDL3rs8076131, rs12603332, and rs3744246 and GSDMB rs7216389 variants with asthma. Large sample size and representative population-based studiesand TDT studies with homogeneous asthmatic patients and well-matched controls are warranted to confirm this finding.

Distinct mutations in MLH1 and MSH2 genes in Hereditary Non-polyposis Colorectal Cancer (HNPCC) families from China

( Wen Qian Wei ),( Fang Qi Liu ),( Lei Liu ),( Zuo Feng Li ),( Xiao Yan Zhang ),( Fan Jiang ),( Qu Shi ),( Xiao Yan Zhou ),( Wei Qi Sheng ),( San Jun Cai ),( Xuan Li ),( Ye Xu ),( Peng Nan ) 생화학분자생물학회(구 한국생화학분자생물학회) 2011 BMB Reports Vol.44 No.5

Hereditary non-polyposis Colorectal Cancer (HNPCC) is an autosomal dominant inheritance syndrome. HNPCC is the most common hereditary variant of colorectal cancer (CRC), which accounts for 2-5% CRCs, mainly due to hMLH1 and hMSH2 mutations that impair DNA repair functions. Our study aimed to identify the patterns of hMSH2 and hMLH1 mutations in Chinese HNPCC patients. Ninety-eight unrelated families from China meeting Amsterdam or Bethesda criteria were included in our study. Germline mutations in MLH1 and MSH2 genes, located in the exons and the splice-site junctions, were screened in the 98 probands by direct sequencing. Eleven mutations were found in ten patients (11%), with six in MLH1 (54.5%) and five in MSH2 (45.5%) genes. One patient had mutations in both MLH1 and MSH2 genes. Three novel mutations in MLH1 gene (c.157_160delGAGG, c.2157dupT and c.-64G>T) were found for the first time, and one suspected hotspot in MSH2 (c.1168C>T) was revealed. [BMB reports 2011; 44(5): 317-322]