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A Study on Tennis Competition Enhancement Technology on the Basis of Virtual Reality Technology
Li Ai’jun 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.12
With the development of the science and technology, as one of the hot direction of IT, the virtual reality technology has been widely used in more and more fields. Wherein, in sports competition, it is particularly prominent. This paper is based on the related theories of virtual reality, sets up the tennis dynamics model, using ODE technology to operate the simulation system. By simulating the trajectory and collision detection, this paper has drawn a conclusion that virtual reality technology can make accurate and scientific simulation on sports competition both in static and simulation lab environment. Therefore, the computer virtual technology has a catalytic effect on sports competition enhancement technology. Moreover, this paper will open up new ideas for the application of computer virtual technology on sports competition enhancement technology, and also provide the theoretical basis for related researches.
Strength and Deformation Characteristics of Silty Sand Improved by Gravel
Ai-jun Chen,Jia-sheng Zhang 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.2
Silty sand is a poor filler of highway and railway subgrade, and various physical and chemical improving methods have been applied to increase the strength and stability of silty sand. Adding gravel to silty sand is a routine physical improving method. In this paper, large-scale triaxial tests were carried out on silty sand and improved soil which is obtained by adding 4 different proportions of gravel into the silty sand in order to analyze the strength and deformation characteristics of the improved soil. The stress-strain relations obtained from tiaxial tests were analyzed and the effect of coarse particles and fine particles on the strength and deformation of the specimen were also analyzed. The test results show that with more coarse particles and under a higher confining pressure, a greater deviator stress is required to produce the same axial strain. The increase of coarse particles helps to enlarge the angle of internal friction and cohesion, while the increase of fine particles decreases the angle of internal friction and cohesion. Under low confining pressure, the soil specimens with more coarse particles exhibit evident shear dilation. Under high confining pressure, the soil specimens produce a greater volume strain. Adding appropriate amount of gravel into the silt soil can increase its strength and restrain its deformation, but excessive amount of gravel may produce too much volume deformation.
MR Imaging of the Spine at 3.0T with T2-Weighted IDEAL Fast Recovery Fast Spin-Echo Technique
Ai-Jun Ren,Yong Guo,Shu-Ping Tian,Li-Jing Shi,Min-Hua Huang 대한영상의학회 2012 Korean Journal of Radiology Vol.13 No.1
Objective: To compare the iterative decomposition of water and fat with echo asymmetry and the least-squares estimation (IDEAL) method with a fat-saturated T2-weighted (T2W) fast recovery fast spin-echo (FRFSE) imaging of the spine. Materials and Methods: Images acquired at 3.0 Tesla (T) in 35 patients with different spine lesions using fat-saturated T2W FRFSE imaging were compared with T2W IDEAL FRFSE images. Signal-to-noise ratio (SNR)-efficiencies measurements were made in the vertebral bodies and spinal cord in the mid-sagittal plane or nearest to the mid-sagittal plane. Images were scored with the consensus of two experienced radiologists on a four-point grading scale for fat suppression and overall image quality. Statistical analysis of SNR-efficiency, fat suppression and image quality scores was performed with a paired Student’s t test and Wilcoxon’s signed rank test. Results: Signal-to-noise ratio-efficiency for both vertebral body and spinal cord was higher with T2W IDEAL FRFSE imaging (p < 0.05) than with T2W FRFSE imaging. T2W IDEAL FRFSE demonstrated superior fat suppression (p < 0.01) and image quality (p < 0.01) compared to fat-saturated T2W FRFSE. Conclusion: As compared with fat-saturated T2W FRFSE, IDEAL can provide a higher image quality, higher SNR-efficiency, and consistent, robust and uniform fat suppression. T2W IDEAL FRFSE is a promising technique for MR imaging of the spine at 3.0T. Objective: To compare the iterative decomposition of water and fat with echo asymmetry and the least-squares estimation (IDEAL) method with a fat-saturated T2-weighted (T2W) fast recovery fast spin-echo (FRFSE) imaging of the spine. Materials and Methods: Images acquired at 3.0 Tesla (T) in 35 patients with different spine lesions using fat-saturated T2W FRFSE imaging were compared with T2W IDEAL FRFSE images. Signal-to-noise ratio (SNR)-efficiencies measurements were made in the vertebral bodies and spinal cord in the mid-sagittal plane or nearest to the mid-sagittal plane. Images were scored with the consensus of two experienced radiologists on a four-point grading scale for fat suppression and overall image quality. Statistical analysis of SNR-efficiency, fat suppression and image quality scores was performed with a paired Student’s t test and Wilcoxon’s signed rank test. Results: Signal-to-noise ratio-efficiency for both vertebral body and spinal cord was higher with T2W IDEAL FRFSE imaging (p < 0.05) than with T2W FRFSE imaging. T2W IDEAL FRFSE demonstrated superior fat suppression (p < 0.01) and image quality (p < 0.01) compared to fat-saturated T2W FRFSE. Conclusion: As compared with fat-saturated T2W FRFSE, IDEAL can provide a higher image quality, higher SNR-efficiency, and consistent, robust and uniform fat suppression. T2W IDEAL FRFSE is a promising technique for MR imaging of the spine at 3.0T.
Some completely monotonic functions involving the gamma and polygamma functions
Ai-Jun Li,Chao-Ping Chen 대한수학회 2008 대한수학회지 Vol.45 No.1
In this paper, some logarithmically completely monotonic, strongly completely monotonic and completely monotonic functions related to the gamma, digamma and polygamma functions are established. Several inequalities, whose bounds are best possible, are obtained. In this paper, some logarithmically completely monotonic, strongly completely monotonic and completely monotonic functions related to the gamma, digamma and polygamma functions are established. Several inequalities, whose bounds are best possible, are obtained.
Two New Phenolic Glycosides from Curculigo orchioides
Ai-Xue Zuo,Yong Shen,Zhi-Yong Jiang,Xue-Mei Zhang,Jun Zhou,Jun Lü,Ji-Jun Chen 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.3
Two new phenolic glycosides were isolated from the rhizomes of Curculigo orchioides Gaertn.. Based on comprehensive spectroscopic analyses including IR, MS, 1D- and 2D NMR (COSY, HSQC, and HMBC), their structures were elucidated as 3-hydroxyl-5-methyphenol-1-O-[β-D-glucopyranosyl-(1→3)-β-D-glucopyranoside (1) and 1',3'-dimethoxyl-4-hydroxyalangifolioside (2).
New analytical solutions to water wave diffraction by vertical truncated cylinders
Ai-jun Li,Yong Liu 대한조선학회 2019 International Journal of Naval Architecture and Oc Vol.11 No.2
This study develops new analytical solutions to water wave diffraction by vertical truncated cylinders in the context of linear potential theory. Three typical truncated surface-piercing cylinders, a submerged bottom-standing cylinder and a submerged floating cylinder are examined. The analytical solutions utilize the multi-term Galerkin method, which is able to model the cube-root singularity of fluid velocity near the edges of the truncated cylinders by expanding the fluid velocity into a set of basis function involving the Gegenbauer polynomials. The convergence of the present analytical solution is rapid, and a few truncated numbers in the series of the basis function can yield results of six-figure accuracy for wave forces and moments. The present solutions are in good agreement with those by a higher-order BEM (boundary element method) model. Comparisons between present results and experimental results in literature and results by Froude-Krylov theory are conducted. The variation of wave forces and moments with different parameters are presented. This study not only gives a new analytical approach to wave diffraction by truncated cylinders but also provides a reliable benchmark for numerical investigations of wave diffraction by structures.
Regulatory Mechanism of Spindle Movements during Oocyte Meiotic Division
Ai, Jun-Shu,Li, Mo,Schatten, Heide,Sun, Qing-Yuan Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.11
Female germ cell meiotic divisions are typically asymmetric, giving rise to two daughter cells with different sizes. Spindle movements including spindle migration from the oocyte center to the cortex and spindle rotation from parallel to perpendicular (typically in the mouse) at the cortex are crucial for these asymmetric divisions and therefore are crucial for gamete production. Different regulatory mechanisms for spindle movements have been determined in different species and a wide variety of different molecular components and processes that are involved in spindle movements have also been identified in different species. Here, we review the current state of knowledge as well as our understanding of mechanisms for spindle movements in different systems with focus on three main aspects: microtubules (MT), microfilaments (MF) and molecules associated with cytoskeletal organization as well as molecules that are not directly related to the cytoskeleton. How they might interact or function independently during female meiotic divisions in different species is discussed in detail.
SOME COMPLETELY MONOTONIC FUNCTIONS INVOLVING THE GAMMA AND POLYGAMMA FUNCTIONS
Li, Ai-Jun,Chen, Chao-Ping Korean Mathematical Society 2008 대한수학회지 Vol.45 No.1
In this paper, some logarithmically completely monotonic, strongly completely monotonic and completely monotonic functions related to the gamma, digamma and polygamma functions are established. Several inequalities, whose bounds are best possible, are obtained.
Significance of Oligoclonal Bands after Stem Cell Transplantation in Multiple Myeloma Cases
Liu, Ai-Jun,Zong, Hong,Yang, Guang-Zhong,Zhai, Yu-Hua,Li, Li-Hong Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4
Objective: To determine the characteristics of oligoclonal bands that are frequently detected by serum protein electrophoresis (SPEP) and immunofixation electrophoresis (IFE) after stem cell transplantation. Methods: We retrospectively analyzed 56 patients with multiple myeloma (MM) undergoing transplantation, and standard immunofixation electrophoresis was used to identify and quantify paraproteins. Results: The median follow-up was 35 months (range, 10-76months) and 21 patients relapsed. Twelve (25.0%) demonstrated oligoclonal bands after a median time 1.4 months (range, 1-3months), with a median duration of 5.8 months (range, 1-15months). The majority patients with oligoclonal bands had normal quantities of immunoglobulins and the one year event free survival (EFS) was 92%, even higher than for patients without OBs (P=0.002). Conclusion: Oligoclonal bands frequent develop post-transplantation in MM cases. In the vast majority of patients, they may not represent relapsed disease, and more likely represent a transient phenomenon representing recovery of impaired immunoglobulin production.