Sea Environmental Design Criteria for Coastal and Offshore Structures

Defu Liu 한국해안해양공학회 1996 학술강연회 발표논문초록집 Vol.1 No.1

Extreme sea statistics and combinations of environmental events or response for structures are very important problem in performance cvaluation and design of coastal and Offshore structures. A probabilistic method is developed that leads to the combination of Typhoon (hurricane) or winter storm induces winds, waves, currents and surge for a generic site. The traditional recommendation for the fixed structures is a combination of the 100 years maximum wave height with the 100 years wind and current. This approach is, however, unduly conservative, since the largest wind, wave and current values in 100 years are not experted to occur at precisely the same time. Previous studies of combinations of extreme sea environmental conditions fall into two categories: first, the generic load model defines a surface in the multivariate space of meteorologicaloceanic variables, such as the joint probability of waves, currents, winds and storm surge: second, use the structural response to combine the environmental variables, such as overturning moment (OTM), base shear forces and etc. [1-4]. While the great majority of publications are concentrated in combinations of responses, although 100 years response is not corresponding to wave, wind and current with 100 years joint probability. Since the combination design criteria is considered with extreme statistics of individual environmental events and their joint probability,in this paper some new concept for mentioned above problems is proposed.

Characterization of a Strain of Malva Vein Clearing Virus in Alcea rosea via Deep Sequencing

Defu Wang,Liyan Cui,Yanni Pei,Zhennan Ma,Shaofei Shen,Dandan Long,Lingyu Li,Yanbing Niu 한국식물병리학회 2020 Plant Pathology Journal Vol.36 No.5

Malva vein clearing virus (MVCV) is a member of the Potyvirus species, and has a negative impact on the aesthetic development of Alcea rosea. It was first reported in Germany in 1957, but its complete genome sequence data are still scarce. In the present work, A. rosea leaves with vein-clearing and mosaic symptoms were sampled and analyzed with small RNA deep sequencing. By denovo assembly the raw sequences of virus-derived small interfering RNAs (vsiRs) and whole genome amplification of malva vein cleaning virus SX strain (MVCVSX) by specific primers targeting identified contig gaps, the full-length genome sequences (9,645 nucleotides) of MVCV-SX were characterized, constituting of an open reading frame that is long enough to encode 3,096 amino acids. Phylogenetic analysis showed that MVCVSX was clustered with euphorbia ringspot virus and yam mosaic virus. Further analyses of the vsiR profiles revealed that the most abundant MVCV-vsiRs were between 21 and 22 nucleotides in length and a strong bias was found for “A” and “U” at the 5′-terminal residue. The results of polarity assessment indicated that the amount of sense strand was almost equal to that of the antisense strand in MVCV-vsiRs, and the main hot-spot region in MVCV-SX genome was found at cylindrical inclusion. In conclusion, our findings could provide new insights into the RNA silencing-mediated host defence mechanism in A. rosea infected with MVCV-SX, and offer a basis for the prevention and treatment of this virus disease.

Complete Genome Sequencing and Infectious cDNA Clone Construction of Soybean Mosaic Virus Isolated from Shanxi

Defu Wang,Liyan Cui,Li Zhang,Zhennan Ma,Yanbing Niu 한국식물병리학회 2021 Plant Pathology Journal Vol.37 No.2

Soybean mosaic virus (SMV) is the predominant viral pathogen that affects the yield and quality of soy- bean. The natural host range for SMV is very narrow, and generally limited to Leguminosae. However, we found that SMV can naturally infect Pinellia ternata and Atractylodes macrocephala. In order to clarify the molecular mechanisms underlying the cross- family infection of SMV, we used double-stranded RNA extraction, rapid amplification of cDNA ends polymerase chain reaction and Gibson assembly tech- niques to carry out SMV full-length genome amplifi- cation from susceptible soybeans and constructed an infectious cDNA clone for SMV. The genome of the SMV Shanxi isolate (SMV-SX) consists of 9,587 nt and encodes a polyprotein consisting of 3,067 aa. SMV-SX and SMV-XFQ008 had the highest nucleotide and ami- no acid sequence identities of 97.03% and 98.50%, re- spectively. A phylogenetic tree indicated that SMV-SX and SMV-XFQ018 were clustered together, sharing the closest relationship. We then constructed a pSMV-SX infectious cDNA clone by Gibson assembly technology and used this clone to inoculate soybean and Ailanthus altissima; the symptoms of these hosts were similar to those caused by the virus isolated from natural infected plant tissue. This method of construction not only makes up for the time-consuming and laborious defect of traditional methods used to construct infec- tious cDNA clones, but also avoids the toxicity of the Potyvirus special sequence to Escherichia coli, thus providing a useful cloning strategy for the construction of infectious cDNA clones for other viruses and laying down a foundation for the further investigation of SMV cross-family infection mechanisms.

Effect of changes in lung physical properties on microwave ablation zone during respiration

Defu Yang,Miao Cao 대한의용생체공학회 2020 Biomedical Engineering Letters (BMEL) Vol.10 No.2

Microwave ablation is a promising minimally invasive treatment for cancer. However, due to the respiratory movement ofthe lungs, it is very diffi cult to accurately predict and control the microwave ablation zone. Therefore, the infl uence of thechanges of the physical parameters of the respiratory process on the microwave ablation zone is studied. Firstly, based onthe 4D-CT describing the respiratory process of the lungs, all the image data are from 100 non-small cell lung cancer radiotherapypatients (50 males and 50 females, average 58 years, range 55–61 years). According to the theory of porous media,the change of the eff ective thermal conductivity of the lung tissue during the breathing process is obtained. The eff ectivethermal conductivity of the lung parenchyma during respiration varies from 0.16 to 0.20 W/m °C, with the lowest vale at theend of inspiration and the highest at the end of expiration. The transient problems during microwave ablation of pulmonarytissue are analyzed by fi nite element method. The changes of relative permittivity, conductivity and density changes duringthe breathing process are also considered. The results show that the microwave ablation zone is signifi cantly larger underdynamic physical parameters. At the end of expiration, when the tissue parameter is set to constant, the ablation lesion areais more concentrated around the tip and slot of the antenna, and the backward heating eff ect is smaller, Ablation volume wassuperior in nonventilated lungs. Therefore, single-lung ventilation can be considered during pulmonary ablation to reducethe impact of breathing on the ablation area. These fi ndings can be useful to further our understanding the MWA and holdpromise towards achieving successful treatment objective as well as enhanced therapeutic output via improved treatmentplanning and strategy. This study provides the basis for clinical pulmonary ablation and can also be used as a preoperativeplan to provide guidance to physicians.

Combination Sea Environmental Design Criteria for Marine Structures

Defu, Liu 목포해양대학교해사산업기술연구소 1997 심포지움강연논집 Vol.1997 No.11

Extreme sea statistics and combinations of extreme events or response for structures are very important problem in performance evaluation and design of coastal and Offshore structures. A probabilistic method is developed that leads to the combination of Typhoon(Hurricane) or winter storm induces winds, waves, currents and surge for generic site. The traditional recommendation for the fixed structures in a combination of the 100years maximum wave height with the 100 years wind and current. This approach is, however, unduly conservative, since the largest wind, wave and current values in 100years are not expected to occur at precisely the same time. Previous studies of combinations of extreme sea environmental conditions fall into two catagories : first, the generic load model defines a surface in the multivariate space of meteorological-oceanic variables, such as the joint probability of waves, currents winds and storm surges; second use the structural response to combine the environmental variables, such as overturning moment(OTM), base shear fores and etc.. While the great majority of publications are concentrated in combinations of responses, although 100 years response is not corresponding to wave, wind and current with 100 years joint probability. Since the combination design criteria is considered with extreme statistics of individual environmental events and their joint probability, in this paper some new concept for mentioned above problems is proposed.

A New Subband Image Coding for Multimedia Communications

Defu Cai,Wenkai Du,Jiaofang Chen 한국통신학회 1993 Asia-Pacific Conference on Communications Vol.2 No.1

Effects of Maize Source and Complex Enzymes on Performance and Nutrient Utilization of Broilers

Tang, Defu,Hao, Shengyan,Liu, Guohua,Nian, Fang,Ru, Yingjun Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.12

The objective of this study was to investigate the effect of maize source and complex enzymes containing amylase, xylanase and protease on performance and nutrient utilization of broilers. The experiment was a $4{\times}3$ factorial design with diets containing four source maize samples (M1, M2, M3, and M4) and without or with two kinds of complex enzyme A (Axtra XAP) and B (Avizyme 1502). Nine hundred and sixty day old Arbor Acres broiler chicks were used in the trial (12 treatments with 8 replicate pens of 10 chicks). Birds fed M1 diet had better body weight gain (BWG) and lower feed/gain ratio compared with those fed M3 diet and M4 diet (p<0.05). Apparent ileal crude protein digestibility coefficient of M2 was higher than that of M3 (p<0.05). Apparent metabolisable energy (AME) and nitrogen corrected AME (AMEn) of M1 were significant higher than those of M4 (p<0.05). Supplementation of the basal diets with enzyme A or B improved the BWG by 8.6% (p<0.05) and 4.1% (p>0.05), respectively. The fresh feces output was significantly decreased by the addition of enzyme B (p<0.05). Maize source affects the nutrients digestibility and performance of broilers, and a combination of amylase, xylanase and protease is effective in improving the growth profiles of broilers fed maize-soybean-rapeseed-cotton mixed diets.

Effects of Replacing Corn with Brown Rice or Brown Rice with Enzyme on Growth Performance and Nutrient Digestibility in Growing Pigs

Zhang, Defu,Li, Defa,Piao, X.S.,Han, In K.,Yang, Chul J.,Shin, In S.,Dai, J.G.,Li, J.B. Asian Australasian Association of Animal Productio 2002 Animal Bioscience Vol.15 No.9

A 4 week experiment was designed to study the effects of replacing corn with Chinese brown rice or adding different amylase in brown rice basal diet on growth performance and apparent fecal digestibilities of nutrients in growing pigs. One hundred and eight cross-bred pigs (Duroc${\times}$Landrace${\times}$Large White), weighing an average of $18.35{\pm}0.12kg$, were randomly assigned to 6 treatments with 6 replications per treatment. Diet in treatment 1 was corn-soybean meal basal diet, and in treatment 2, 3 and 4, corn was replaced by brown rice on rates of 33.3%, 66.7% and 100% respectively on the basis of treatment 1. And diets in treatment 5 and 6 were similar to treatment 4 except two kinds of amylases, glucoamylase and ${\alpha}$-amylase, were added respectively. The brown rice used in this experiment was husked from one kind of early, long grain, non-glutinous rice (ELGNR, indica rice) in southern China. The results indicated that there was a slight improvement in growth performance of pigs in brown rice treatments (p>0.05). The blood urea nitrogen value in treatment 2 was lower than that in treatment 1 (p<0.05). The differences of apparent fecal digestibilities of most nutrients were significant (p<0.05) except CP. Digestibilities of GE, OM and DM in treatment 4 were the best and digestibility of crude fat in treatment 5 appeared best (p<0.05). Contrast results between treatment 1 and treatment 2 to 4 indicated that the digestibility of GE, OM and DM increased significantly with the replacing rates of brown rice (p<0.05). Contrast results between treatment 4 and 5 indicated that adding glucoamylase in brown rice diet increased growth performance slightly (p>0.05) but not for digestibilities. This experiment shows a positive effect of brown rice on growth performance, especially on nutrient digestibility.

Robust Output Feedback Tracking Control for a Class of Perturbed Systems Using NDOB and Nonlinear Continuous Predictive Control

Shaoming He,Defu Lin 제어·로봇·시스템학회 2016 International Journal of Control, Automation, and Vol.14 No.2

This paper presents a new robust output feedback tracking control scheme for a class of higher-orderuncertain systems. Since traditional nonlinear continuous predictive control requires accurate system model aswell as full system states to synthesize a controller, a composite control methodology is adopted in the proposedscheme. Specifically, the nonlinear disturbance observer (NDOB) is used to estimate the lumped uncertainty andthe unmeasured system states in an integrated manner while the nonlinear continuous predictive control regulatesthe system states to track the desired reference signal asymptotically. Detailed stability analysis is also presentedfor the closed-loop nonlinear observer-controller structure through two steps. Then, the obtained results are appliedto missile autopilot design to track the desired angle-of-attack signal. Finally, numerical simulations with somecomparisons are provided to demonstrate the effectiveness of the proposed formulation.

Effect of Heat Treatment on Microstructure and Mechanical Properties of Mg-10Li-3Al-3Zn-0.22Si Alloy

Yazhao Shen,Defu Li,Shengli Guo,Jiangtao Guo 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.10

The microstructure evolution and mechanical properties of as-extruded Mg-10Li-3Al-3Zn-0.22Si during heat treatment from473 to 673 K were investigated in this paper, and then the strengthening mechanism and fracture behavior of the studied alloywas also analyzed. Experimental results show that the matrix of as-extruded Mg-10Li-3Al-3Zn-0.22Si alloy mainly consistsof α-Mg and β-Li, and dispersive granular phases are AlLi and Li2MgAl. Mg2Siphase shows banded distribution alongextrusion direction. The morphology of α-Mg is from long strip to nearly spherical block at 573 K. The α-Mg reprecipitatesfrom β-Li matrix in the orientation relationship: (0001) α-Mg // (110) β-Li, [11 −2 0] α-Mg // [1 −1 0] β-Li at 623 K. While theAl-rich granular phase is decomposed and dissolve into the gradually, and then AlLi increase again at 673 K, which may becaused by the dissolution at high temperature and precipitation during air cooling in heat treatment. Besides, the solid solutionand dispersion strengthening enhances the strength of alloy after heat treatment. After heat-treated at 573 K for 1 h and thenair cooling, alloy presents excellent mechanical properties with the ultimate tensile strength of 253 ± 3 MPa and elongationof 27 ± 3%, respectively. Compared with the extruded state, ultimate tensile strength of alloy can be increased by about 49%.