Plant leaf detection using modified active shape models

Xia, C.,Lee, J.M.,Li, Y.,Song, Y.H.,Chung, B.K.,Chon, T.S. Academic Press 2013 BIOSYSTEMS ENGINEERING Vol.116 No.1

We propose an in situ detection method of multiple leaves with overlapping and occlusion in greenhouse conditions. Initially a multilayer perceptron (MLP) is used to classify partial boundary images of pepper leaves. After the partial leaf boundary detection, active shape models (ASMs) are subsequently built to employ the images of entire leaves based on a priori knowledge using landmark. Two deformable models were developed with pepper leaves: Boundary-ASM and MLP-ASM. Matching processes are carried out by deforming the trained leaf models to fit real leaf images collected in the greenhouse. MLP-ASM detected 76.7 and 87.8% of overlapping and occluded pepper leaves respectively, while Boundary-ASM showed detection rates of 63.4 and 76.7%. The detection rates by the conventional ASM were 23.3 and 29.3%. The leaf models trained with pepper leaves were further tested with leaves of paprika, in the same family but with more complex shapes (e.g., holes and rolling). Although the overall detection rates were somewhat lower than those for pepper, the rates for the occluded and overlapping leaves of paprika were still higher with MLP-ASM (ranging from 60.4 to 76.7%) and Boundary-ASM (ranging from 50.5 to 63.3%) than using the conventional active shape model (from 21.6 to 30.0%). The modified active shape models with the boundary classifier could be an efficient means for detecting multiple leaves in field conditions.

Effects of Feeding Methylthio Butyric Acid Isopropyl Ester on Postpartum Performance and Metabolism in Dairy Cows

Xia, K.,Xi, W.B.,Wang, Z.B.,Wang, Y.,Zhang, Y.G. Asian Australasian Association of Animal Productio 2012 Animal Bioscience Vol.25 No.5

The present experiment aimed to evaluate the effect of HMBi on the production performance and metabolism in dairy cows. Thirty multiparous Holstein dairy cows under similar conditions were randomly assigned to three dietary treatments; i) Control, a basal diet; ii) T1, a basal diet plus HMBi (0 g prepartum and 18 g postpartum); and iii) T2, a basal diet plus HMBi (10 g prepartum and 18 g postpartum). Treatments were initiated 21 d before expected calving and continued through 91 d postpartum. HMBi was top-dressed onto the total mixed ration of each cow. Treatments did not affect dry matter intake, plasma urea nitrogen, peak milk yield, days to peak milk yield, nonesterified fatty acid, glutamate pyruvate transaminase, glutamic oxalaetic transaminase, milk fat content, milk protein content, milk lactose content, and milk solid non-fat content. The milk composition yields were increased by the HMBi-supplemented treatment. The T1 and T2 treatments increased the yields of 4% fat-corrected milk yield, milk fat, milk protein, and milk lactose compared with the control. Although there was no difference in the milk composition of the control and T2-treated cows, the T2-treated cows exhibited higher milk fat yield (increased by 74 g/d), lower milk urea nitrogen (reduced by 3.41%), and plasma ${\beta}$-hydroxy butyrate than the control cows. The results indicate that HMBi supplementation to diet has beneficial effects, and that there is no difference between supplementation at prepartum and starting only at parturition.

Synthesis and biological evaluation of diverse tetrahydrobenzofuran-4-ones as potent antibacterial agents

Xia, L.,Idhayadhulla, A.,Lee, Y.R.,Kim, S.H.,Wee, Y.J. Korean Society of Industrial and Engineering Chemi 2015 Journal of industrial and engineering chemistry Vol.22 No.-

Diverse 3,5,6,7-tetrahydrobenzofuran-4-one derivatives (3a-3n) were synthesized in high yields by ruthenium complex or rhodium complex catalyzed [3+2] cycloaddition. The antibacterial activities of these 3,5,6,7-tetrahydrobenzofuran-4-ones were evaluated against Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Enterobacter aerogenes) and Gram-positive bacteria (Bacillus cereus and Staphylococcus aureus). In particular, compound 3b showed the highest antibacterial activity against P. aeruginosa and S. aureus (both MICs: 2μg/mL). Compound 3l, which has the 2H-pyrano[2,3-b]benzofuran skeleton, exhibited excellent inhibitory activity against B. cereus (MIC: 0.5μg/mL) as compared with ciprofloxacin (MIC: 2μg/mL) and ampicillin (MIC: 1μg/mL).

Equivalent stiffness method for nonlinear analysis of stay cables

Xia, G.Y.,Cai, C.S. Techno-Press 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.39 No.5

In the famous equivalent elasticity modulus method proposed by Ernst for the geometrical nonlinear analysis of stay cables, the cable shape was assumed as a parabolic curve, and only a part of the gravity load normal to the chord was taken into account with the other part of gravity load parallel to the chord being ignored. Using the actual catenary curve and considering the entire gravity load of stay cables, the present study has derived the equivalent stiffness method to analyze the sag effect of stay cables in cable-stayed bridges. The derived equivalent stiffness can be degenerated into Ernst's equivalent elasticity modulus method with some approximations. Therefore, the Ernst's method is a special and approximate formulation of the present method. The derived equivalent stiffness provides a theoretical explanation for the famous Ernst's formula.

Effects of Copper-bearing Montmorillonite (Cu-MMT) on Escherichia coli and Diarrhea on Weanling Pigs

Xia, M.S.,Hu, C.H.,Xu, Z.R.,Ye, Y.,Zhou, Y.H.,Xiong, L. Asian Australasian Association of Animal Productio 2004 Animal Bioscience Vol.17 No.12

Copper-bearing montmorillonite (Cu-MMT) was produced by $Cu^{2+}$ cation exchange reaction. X-ray diffraction analysis showed that that the (001) basal spacing of the MMT crystal lattice increased from 1.544 to 1.588 nm after $Cu^{2+}$ exchange. This indicated that $Cu^{2+}$ entered into interlayer position of MMT as a hydrated cation or composite cation. In vitro results indicated that Cu-MMT had antibacterial activity on Escherichia coli $K_{88}$. Cu-MMT had unbalanced positive charge after cation exchange. Its antibacterial activity resulted from two aspects, one was electrostatic attraction which made E. coli $K_{88}$ being adhered on the montmorillonite surface, the other was the $Cu^{2+}$ slowly released, which could kill bacteria. In an in vivo study, four replicates of eight weanling pigs were assigned to each of two dietary treatments to study the effects of Cu-MMT on diarrhea, E. coli in the lumen of the jejunum and morphology of jejunal mucosa. As compared to the control, supplementation of the diet with 0.2% Cu-MMT improved average daily gain by 12.50% (p<0.05) and decreased F/G by 9.42% (p<0.05). The mean diarrhrea incidence was decreased by 71.80% (p<0.05). The viable counts of Escherichia coli in jejunal contents were significantly reduced (p<0.05). Villus height and the villus height to crypt depth ratio at the jejunal mucosa were increased by 19.09% (p<0.05) and 37.10% (p<0.05), respectively.

Native-sized recombinant spider silk protein produced in metabolically engineered Escherichia coli results in a strong fiber

Xia, X.-X.,Qian, Z.-G.,Ki, C.S.,Park, Y.H.,Kaplan, D.L.,Lee, S.Y. National Academy of Sciences 2010 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.107 No.32

Investigation of mode identifiability of a cable-stayed bridge: comparison from ambient vibration responses and from typhoon-induced dynamic responses

Y.Q. Ni,Y.W. Wang,Y.X. Xia 국제구조공학회 2015 Smart Structures and Systems, An International Jou Vol.15 No.2

Modal identification of civil engineering structures based on ambient vibration measurement has been widely investigated in the past decades, and a variety of output-only operational modal identification methods have been proposed. However, vibration modes, even fundamental low-order modes, are not always identifiable for large-scale structures under ambient vibration excitation. The identifiability of vibration modes, deficiency in modal identification, and criteria to evaluate robustness of the identified modes when applying output-only modal identification techniques to ambient vibration responses were scarcely studied. In this study, the mode identifiability of the cable-stayed Ting Kau Bridge using ambient vibration measurements and the influence of the excitation intensity on the deficiency and robustness in modal identification are investigated with long-term monitoring data of acceleration responses acquired from the bridge under different excitation conditions. It is observed that a few low-order modes, including the second global mode, are not identifiable by common output-only modal identification algorithms under normal ambient excitations due to traffic and monsoon. The deficient modes can be activated and identified only when the excitation intensity attains a certain level (e.g., during strong typhoons). The reason why a few low-order modes fail to be reliably identified under weak ambient vibration excitations and the relation between the mode identifiability and the excitation intensity are addressed through comparing the frequency-domain responses under normal ambient vibration excitations and under typhoon excitations and analyzing the wind speeds corresponding to different response data samples used in modal identification. The threshold value of wind speed (generalized excitation intensity) that makes the deficient modes identifiable is determined.

Effects of Dietary Polyunsaturated Fatty Acids on Antibody Production and Lymphocyte Proliferation of Laying Hens

Xia, Z.G.,Guo, Y.M.,Chen, S.Y.,Yuan, J.M. Asian Australasian Association of Animal Productio 2003 Animal Bioscience Vol.16 No.9

The purpose of present study was to assess the effect of polyunsaturated fatty acids (PUFA) on the immune responses of laying hens. Three hundred and sixty hens at the age of 60 weeks were randomly assigned to ten diets, which contained no oil (CK), 1%, 3%, 5% fish oil (FO); 2%, 4%, 6% linseed oil (LO) and 2%, 4%, 6% corn oil (CO). After 5 weeks of feeding experimental diets, humoral and cellular immune responses were assayed. Laying hens were injected with Sheep Red Blood Cell (SRBC) and Bovine Serum Albumin (BSA) and antibody titers, which were measured on d6, d10, d14 after primary challenge and on d5, d9, d13 after secondary challenge. Concanavalin (ConA) and lipopolysaccharide (LPS) -stimulated proliferation of peripheral blood and spleen lymphocytes were assessed by [$^3$H] thymidine incorporation at the week age of 5 and 10, respectively. The results showed that antibody titers in FO-fed and LO-fed laying hens were higher than that in laying hens fed CO. The proliferation response to ConA was lower in laying hens that fed oils rich in n-3 fatty acids than that in laying hens fed CO. Higher level n-3 fatty acids can improve immune functions of laying hens. In conclusion, dietary fat source and level had a significant impact on immune responses of laying hens.

Pulse Compression by Difference-Frequency Generation with Engineered Aperiodic Optical Superlattic

Y. Kong,Xianfeng Chen,P. Li,Y. Xia 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.51 No.II

We theoretically propose a procedure for designing quasi-phase-matching (QPM) gratings for compressing ultrashort optical pulses during difference-frequency generation. The grating consists of blocks of crystal with the same block length and the direction of spontaneous polarization of each block is determined by an optimal algorithm through which the sign of the nonlinear coefficient of each block is optimized to make the phase response of the grating the same for different wavelengths of the output idler waves so that the generated idler pulse from the end of the crystal will be compressed during difference-frequency generation. Pumped by a cw (or a quasi-cw) laser, the generated idler pulse is compressed beyond its Fourier-transform limit in the simulations

SHM benchmark for high-rise structures: a reduced-order finite element model and field measurement data

Y.Q. Ni,Y. Xia,W. Lin,W.H. Chen,J.M. Ko 국제구조공학회 2012 Smart Structures and Systems, An International Jou Vol.10 No.5

The Canton Tower (formerly named Guangzhou New TV Tower) of 610 m high has been instrumented with a long-term structural health monitoring (SHM) system consisting of over 700 sensors of sixteen types. Under the auspices of the Asian-Pacific Network of Centers for Research in Smart Structures Technology (ANCRiSST), an SHM benchmark problem for high-rise structures has been developed by taking the instrumented Canton Tower as a host structure. This benchmark problem aims to provide an international platform for direct comparison of various SHM-related methodologies and algorithms with the use of realworld monitoring data from a large-scale structure, and to narrow the gap that currently exists between the research and the practice of SHM. This paper first briefs the SHM system deployed on the Canton Tower, and the development of an elaborate three-dimensional (3D) full-scale finite element model (FEM) and the validation of the model using the measured modal data of the structure. In succession comes the formulation of an equivalent reduced-order FEM which is developed specifically for the benchmark study. The reducedorder FEM, which comprises 37 beam elements and a total of 185 degrees-of-freedom (DOFs), has been elaborately tuned to coincide well with the full-scale FEM in terms of both modal frequencies and mode shapes. The field measurement data (including those obtained from 20 accelerometers, one anemometer and one temperature sensor) from the Canton Tower, which are available for the benchmark study, are subsequently presented together with a description of the sensor deployment locations and the sensor specifications.