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Search Results: 1 - 10 of 10666 matches for " Yakun Du "
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Arthroscopy Assisted Lesion Clearance and Bone Graft, Titanium Rod Support Treatment of Early Stage Osteonecrosis of the Femoral Head of the Postoperative Survival Rate Analysis  [PDF]
Xingming Yang, Wei Shi, Yakun Du, Lei Zhang
Surgical Science (SS) , 2017, DOI: 10.4236/ss.2017.81005
Abstract: Objective: To assess the curative effect of the stage II femoral head necrosis treated by arthroscopy assisted lesion clearance, bone graft and titanium rod support. Methods: All the patients (including 58 patients 74 hips) were diagnosed as stage II femoral head necrosis according to the ARCO staging system during 2003-2013. In these patients, 15 hips were stage IIA, 34 hips were stage IIB and 25 hips were stage IIC. Located by C-arm and assisted by arthroscopy, minimally-invasive percutaneous pulp core decompression and lesion clearance within the femoral head were accurately performed, and then, the OAM composite of autologous bone marrow was implanted and the femoral head was supported using the titanium rod. Follow-up including the pain score, the Harris hip score and X-ray observation for disease progression were achieved at 6, 12, 24 and 36 months postoperatively, Kaplan-Meier survival curve was used for the survival analysis. Result: The VAS score and the Harris score after operation were better THRAn THRAt of before the surgery, the difference had statistical significance (p < 0.05). As for the X-ray staging, 5 cases (5 hips) progressed from stage IIB to stage IIC, the femoral head of 6 cases (6 hips) staged IIC collapsed at 24 months after the operation and then underwent THRA after 30 months. In this study, the total improvement rate after the surgery was 79.72% (93.33% for IIA, 82.35% for IIB and 68% for IIC). The total survival rate of these patients was 64.2% (95% CI, 64.2% - 90.1%). Conclusion: Arthroscopy assisted lesion clearance, bone graft and titanium rod support to treat the stage II osteonecrosis of the femoral head are effective and can prevent the femoral head from collapsing. But for stage IIC patients who had a history of the use of hormone, this surgery should be chosen carefully because the outcome is always very poor.
The Comparison of the Manifestation of the Clinical Imageology and Pathology between the Brucellar Spondylitis and the Spine Turberculosis  [PDF]
Xinming Yang, Xianyong Meng, Wei Shi, Yakun Du, Lei Zhang, Yaoyi Wang
Surgical Science (SS) , 2014, DOI: 10.4236/ss.2014.52014
Abstract:


Objective: To improve the clinical differential diagnosis level, the clinical manifestation of the brucellar spondylitis and the spine turberculosis were discussed in this paper. Method: The study was completed in the No. 1 Affiliated Hospital of Hebei North University in Zhangjiakou City, Hebei Province, China, from January 2001 to December 2013 by Analyzing the X-ray, CT scanning and MRI of 257 cases of the brucellar spondylitis retrospectively and comparing with the clinical imageology and pathology 332 cases of turberculosis of the spine diagnosed finally. Results: The brucellar spondylitis: The focuses usually locate in the lumbar vertebra and L4, 5 has the highest occurrence rate. The focuses are often small but multiple, and limited to the edge of the vertebra. Hyperostosis and osteoscterosis are usually found in the tissuses around the focuses. There are often new focuses in the newborn bones, and the destruction of intervertebral discs is usually slight. Hyperostosis and osteoscterosis might be found in the surfaces of the joints. The densites of the bones close to the focuses become high. There were less or no paravertebral abscesses but inflammational granuloma can be found frequently. Turberculosis of the spine: The focuses are usually located in the thoracic and lumbar vertebra, and are characterized by the destruction of the vertebra and the intervertebral discs, accompanied by the appearance of

On Kakeya-Nikodym type maximal inequalities
Yakun Xi
Mathematics , 2015,
Abstract: We show that for any dimension $d\ge3$, one can obtain Wolff's $L^{(d+2)/2}$ bound on Kakeya-Nikodym maximal function in $\mathbb R^d$ for $d\ge3$ without the induction on scales argument. The key ingredient is to reduce to a 2-dimensional $L^2$ estimate with an auxiliary maximal function. We also prove that the same $L^{(d+2)/2}$ bound holds for Nikodym maximal function for any manifold $(M^d,g)$ with constant curvature, which generalizes Sogge's results for $d=3$ to any $d\ge3$. As in the 3-dimensional case, we can handle manifolds of constant curvature due to the fact that, in this case, two intersecting geodesics uniquely determine a 2-dimensional totally geodesic submanifold, which allows the use of the auxiliary maximal function.
网络空间向量剖分法识别城市路网网格模式
Grid Pattern Recognition in Street Network Space by Vector Tessellation Method

何亚坤, 艾廷华, 杜欣, 禹文豪
HE Yakun
, AI Tinghua, DU Xin, YU Wenhao

- , 2018, DOI: 10.13203/j.whugis20150757
Abstract: 将道路网络空间视为嵌在2D空间中的独立子空间,利用形态单一的线性单元剖分图结构的边,实现网络空间的栅格化;提取网格模式的典型特征,包括几何和拓扑特征,以栅格单元邻域为目标计算特征值,构建特征向量描述栅格单元,实现对象空间到特征空间的映射,构建空间向量场;基于支持向量机(support vector machine,SVM)实现网格模式分类;结合格式塔原则完善实验结果。将此方法应用于深圳市路网数据,实验结果表明能有效地识别网格模式
A Review of Mindfulness Improves Decision Making and Future Prospects  [PDF]
Si Liu, Yaozhong Liu, Yakun Ni
Psychology (PSYCH) , 2018, DOI: 10.4236/psych.2018.92015
Abstract: With the popularity of mindfulness training among different groups of people, more and more attention has been paid to the positive role of mindfulness. In particular, the improvement of mindfulness on decision-making has been respected by the elite management and practitioners in different industries. There are also different forms of experimental paradigms for different types of decision-making behaviors in research methods. Both behavioral evidence and imaging evidence show that mindfulness training can improve decision-making, both under the social and non-social conditions. Mindfulness training was predominantly driven by an “emotional” system, manifested by an active medial prefrontal cortex, whereas the latter was not dominated by a “rational” system of decision-making processes; on the contrary, posterior insular and thalamic regions with emotional function were more active. Therefore, the emotional system throughout the mindset training affects the whole process of decision-making. In addition, mindfulness affects other possible factors such as attention, compassion, and cognitive control in the decision-making process. At last, based on the existing research deficiencies, this paper analyzed future prospects from the aspects of research methods, research contents and theoretical construction, in order to provide references for future research in this field.
Self-Affirmation through WeChat Moments  [PDF]
Xiangli Wen, Yaozhong Liu, Yakun Ni
Psychology (PSYCH) , 2019, DOI: 10.4236/psych.2019.103026
Abstract: Self-affirmation is helpful for reducing the individual’s defensive response to threats, harvesting and growing from threatening but valuable information. This study examines whether viewing personal WeChat moments is self-affirmative. Browsing WeChat moments of other people that better than yourself will lead to an upward social comparison, but the effect of browsing your own moments is rarely discussed. This study conducts an experiment, and the result proves that browsing WeChat moments is an effective self-affirmation intervention paradigm. The self-affirmation paradigm which is close to daily life deserves further promotion and research.
On Budget Management Strategy for IT Enterprises in Economic Crisis ----A Case Study of Sohu.com
Yakun Wang,Haoyuan Liu
International Business Research , 2009, DOI: 10.5539/ibr.v2n3p72
Abstract: On the second half of the year 2008, a serious economic crisis caused by US sub-prime mortgage crisis covers the world financial market. This crisis strikes heavily on the financial system and impacts on other industry. The crisis advances higher requirements for governments’ macro adjustment and policy supervision. Besides, it requires more for enterprises’ financial budget and management. A series problems turn into demanding challenges for enterprises budgeting and controlling under the crisis. By taking the famous Internet enterprise Sohu.com as an example, this paper probes into the financial budget management and controlling strategy of IT enterprises in economic crisis.
Thoughts on Speeding up the Foreign Economic and Trade Development in Chinese Western Area------ In Perspective of Chongqing City
Yakun Wang,Haoyuan Liu
International Journal of Business and Management , 2009, DOI: 10.5539/ijbm.v4n6p112
Abstract: To implement the grand western development strategy and to speed up the regional economic development is a vital decision of the central government in the new century. Foreign economy and trade is an important component of national economy. To develop the foreign economy and trade in western area and to speed up the opening-up process is significant to drive the economic and social development there. Chongqing city, as the only municipality in western area, the growth of foreign economic and trade development will benefit the western area in general. Therefore, to study how to speed up the foreign economic and trade development in Chongqing is meaningful in practice. Since the execution of reform and opening up policy, the foreign economy and trade have developed fast in Chongqing. But there are problems in attracting foreign capitals.
Study on dynamic angle of repose for submarine pipeline with spoiler on sandy seabed
Lipeng Yang,Bing Shi,Yakun Guo
Journal of Petroleum Exploration and Production Technologies , 2012, DOI: 10.1007/s13202-012-0037-7
Abstract: This paper investigates the dynamic angle of repose underneath the submarine pipeline. A series of tests are carried out to explore the bottom velocity in the scour hole for the case of with spoiler, and gap-ratio in unidirectional current. On that basis, the formulas of dynamic angle of repose in the scour hole are proposed using a sand deposition model. The formulas consider the bottom velocity (which is mainly influenced by the spoiler height and gap-ratio) that dominates the angle of repose. The calculation results are verified by the test data and a good agreement is obtained.
Finite Element Analysis of Turbulent Flows Using LES and Dynamic Subgrid-Scale Models in Complex Geometries
Wang Wenquan,Zhang Lixiang,Yan Yan,Guo Yakun
Mathematical Problems in Engineering , 2011, DOI: 10.1155/2011/712372
Abstract: An innovative computational model is presented for the large eddy simulation (LES) of multidimensional unsteady turbulent flow problems in complex geometries. The main objectives of this research are to know more about the structure of turbulent flows, to identify their three-dimensional characteristic, and to study physical effects due to complex fluid flow. The filtered Navier-Stokes equations are used to simulate large scales; however, they are supplemented by dynamic subgrid-scale (DSGS) models to simulate the energy transfer from large scales toward subgrid-scales, where this energy will be dissipated by molecular viscosity. Based on the Taylor-Galerkin schemes for the convection-diffusion problems, this model is implemented in a three-dimensional finite element code using a three-step finite element method (FEM). Turbulent channel flow and flow over a backward-facing step are considered as a benchmark for validating the methodology by comparing with the direct numerical simulation (DNS) results or experimental data. Also, qualitative and quantitative aspects of three-dimensional complex turbulent flow in a strong 3D blade passage of a Francis turbine are analyzed. 1. Introduction An accurate prediction of turbulent flow inside/over a complex geometry has been one of the most important issues in fluid mechanics. Although formulation of mathematical models to simulate numerically such complex flows is a challenging task, many researches have been developed and some reliable results have been obtained; for example, Klaij [1] developed a space-time discontinuous Galerkin Finite Element Method (DG-FEM) for complex flows, Moin [2] and Conway et al. [3] simulated incompressible flows in complex geometries using large eddy simulation (LES), Zhang et al. [4] investigated the flow through the blades of a swirl generator using LES, and Sagaut [5] simulated the turbulent flow in a true 3D Francis hydroturbine passage considered fluid-structure interaction. Flows with high Reynolds numbers, where the influence of the different turbulence scales must be taken into account, cannot be solved by direct numerical simulation (DNS) due to the large amount of data and unknowns involved in the computational solution. It is only suitable to be used in low Reynolds number flow and for a relative simple flow passage until now. In present, turbulent flows were often governed by the Reynolds Averaged Navier-Stokes (RANS) equations in many industrial fields and solved for the mean flow field together with a chosen turbulence closure model. This approach is based on the
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