A Method of Lossy Compression for RGB565 Format True Color Image

Yan Xijun,Jiang Lei 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.5

In order to solve the issue of embedded image processing, a method of mixed compression for RGB565 format true color image is proposed. According to the inherent correlation of image data, the method adopts the discrete cosine transform and rearrangement to centralize the data that have higher correlation. Finally, it achieves the image compression by improving the run-length coding combined with statistical coding. Experiments show that the method can compress the true color images with RGB565 format effectively on the platform of ARM-Linux, and achieve a good compression ratio.

Modal identification of Canton Tower under uncertain environmental conditions

Xijun Ye,Quansheng Yan,Weifeng Wang,Xiaolin Yu 국제구조공학회 2012 Smart Structures and Systems, An International Jou Vol.10 No.4

The instrumented Canton Tower is a 610 m high-rise structure, which has been considered as a benchmark problem for structural health monitoring (SHM) research. In this paper, an improved automatic modal identification method is presented based on a natural excitation technique in conjunction with the eigensystem realization algorithm (NExT/ERA). In the proposed modal identification method, damping ratio, consistent mode indicator from observability matrices (CMI_O) and modal amplitude coherence (MAC) are used as criteria to distinguish the physically true modes from spurious modes. Enhanced frequency domain decomposition (EFDD), the data-driven stochastic subspace identification method (SSI-DATA) and the proposed method are respectively applied to extract the modal parameters of the Canton Tower under different environmental conditions. Results of modal parameter identification based on output-only measurements are presented and discussed. User-selected parameters used in those methods are suggested and discussed. Furthermore, the effect of environmental conditions on the dynamic characteristics of Canton tower is investigated.

Modal identification of Canton Tower under uncertain environmental conditions

Ye, Xijun,Yan, Quansheng,Wang, Weifeng,Yu, Xiaolin Techno-Press 2012 Smart Structures and Systems, An International Jou Vol.10 No.4

The instrumented Canton Tower is a 610 m high-rise structure, which has been considered as a benchmark problem for structural health monitoring (SHM) research. In this paper, an improved automatic modal identification method is presented based on a natural excitation technique in conjunction with the eigensystem realization algorithm (NExT/ERA). In the proposed modal identification method, damping ratio, consistent mode indicator from observability matrices (CMI_O) and modal amplitude coherence (MAC) are used as criteria to distinguish the physically true modes from spurious modes. Enhanced frequency domain decomposition (EFDD), the data-driven stochastic subspace identification method (SSI-DATA) and the proposed method are respectively applied to extract the modal parameters of the Canton Tower under different environmental conditions. Results of modal parameter identification based on output-only measurements are presented and discussed. User-selected parameters used in those methods are suggested and discussed. Furthermore, the effect of environmental conditions on the dynamic characteristics of Canton tower is investigated.

Identifying Opinion Leader in the Internet Forum

Chao Wu,Chunlin Li,Wei Yan,Youlong Luo,Xijun Mao,Shumeng Du,Mingming Li 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.11

Opinion leader is an authority person who has great influence in BBS. Their linguistic behavior has a huge impact on net citizen’s behavior and thought. In this paper, we propose an algorithm called OLRA (Opinion Leader PageRank Algorithm) based on topic-field to identify opinion leaders in the Internet forum. In the algorithm the closeness degree factor and sentiment analyses are taken into consideration. Meanwhile, these two authority values are defined as the weight of links among users. The data is collected from a number of posts on Tianya forum which is a famous forum in China. In the experiment, the algorithm is compared with Interest-based PageRank algorithm, online time Algorithm, and Experience-based Algorithm, the result shows that the OLRA algorithm can identify opinion leaders than others in the Internet forum effectively.

Optimal fertilizer application for Panax notoginseng and effect of soil water on root rot disease and saponin contents

Pengguo Xia,Hongbo Guo,Hongguang Zhao,Jie Jiao,Michael K. Deyholos,Xijun Yan,Yan Liu,Zongsuo Liang 고려인삼학회 2016 Journal of Ginseng Research Vol.40 No.1

Background: Blind and excessive application of fertilizers was found during the cultivation of Panax notoginseng in fields, as well as increase in root rot disease incidence. Methods: Both “3414” application and orthogonal test designs were performed at Shilin county, Yunnan province, China, for NPK (nitrogen, phosphorus, and potassium) and mineral fertilizers, respectively. The data were used to construct the one-, two-, and three-factor quadratic regression models. The effect of fertilizer deficiency on root yield loss was also analyzed to confirm the result predicted by these models. A pot culture experiment was performed to observe the incidence rate of root rot disease and to obtain the best range in which the highest yield of root and saponins could be realized. Results: The best application strategy for NPK fertilizer was 0 kg/667 m2, 17.01 kg/667 m2, and 56.87 kg/ 667m2, respectively, which can produce the highest root yield of 1,861.90 g (dried root of 100 plants). For mineral fertilizers, calcium and magnesium fertilizers had a significant and positive effect on root yield and the content of four active saponins, respectively. The severity of root rot disease increased with the increase in soil moisture. The best range of soil moisture varied from 0.56 FC (field capacity of water) to 0.59 FC, when the highest yield of root and saponins could be realized as well as the lower incidence rate of root disease. Conclusion: These results indicate that the amount of nitrogen fertilizer used in these fields is excessive and that of potassium fertilizer is deficient. Higher soil moisture is an important factor that increases the severity of the root rot disease.

Optimal fertilizer application for Panax notoginseng and effect of soil water on root rot disease and saponin contents

Xia, Pengguo,Guo, Hongbo,Zhao, Hongguang,Jiao, Jie,Deyholos, Michael K.,Yan, Xijun,Liu, Yan,Liang, Zongsuo The Korean Society of Ginseng 2016 Journal of Ginseng Research Vol.40 No.1

Background: Blind and excessive application of fertilizers was found during the cultivation of Panax notoginseng in fields, as well as increase in root rot disease incidence. Methods: Both "3414" application and orthogonal test designs were performed at Shilin county, Yunnan province, China, for NPK (nitrogen, phosphorus, and potassium) and mineral fertilizers, respectively. The data were used to construct the one-, two-, and three-factor quadratic regression models. The effect of fertilizer deficiency on root yield loss was also analyzed to confirm the result predicted by these models. A pot culture experiment was performed to observe the incidence rate of root rot disease and to obtain the best range in which the highest yield of root and saponins could be realized. Results: The best application strategy for NPK fertilizer was $0kg/667m^2$, $17.01kg/667m^2$, and $56.87kg/667m^2$, respectively, which can produce the highest root yield of 1,861.90 g (dried root of 100 plants). For mineral fertilizers, calcium and magnesium fertilizers had a significant and positive effect on root yield and the content of four active saponins, respectively. The severity of root rot disease increased with the increase in soil moisture. The best range of soil moisture varied from 0.56 FC (field capacity of water) to 0.59 FC, when the highest yield of root and saponins could be realized as well as the lower incidence rate of root disease. Conclusion: These results indicate that the amount of nitrogen fertilizer used in these fields is excessive and that of potassium fertilizer is deficient. Higher soil moisture is an important factor that increases the severity of the root rot disease.