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Support vector machine (SVM) parameter optimization selection is an important research direction, but there is still no systematic theory to guide the selection of the SVM parameters. Since optimizing the SVM parameters by the artificial fish-swarm algorithm tends to fall into the small neighborhood of the approximate optimal solution, we design the AFMC algorithm for the SVM parameter optimization. At the early stage, we use the better parallel optimization performance of the fish-swarm algorithm to quickly gain the approximate optimal solution. Then we use the MonteCarlo algorithm for local searching to achieve a quick and effective strong-approximate optimal solution. The numerical experiments show that the proposed algorithm has better classification performance and faster searching speed, and it is effective and feasible in the SVM parameter optimization. [ABSTRACT FROM AUTHOR]

Solving a large-scale convex quadratic programming problem is the core of the support vector machine. An equivalence complementarity problem can be obtained based on an amended model of the support vector machine(SVM), therefore we propose a non-monotonic trust region algorithm for solving the complementarity problem based on the Fischer-Burmeister complementarity function. The new algorithm need not compute any Hesse or the inverse matrix, thus reducing the amount of computational work. Global convergence of the algorithm is proved without any assumptions. Numerical experiments show that the running speed of the algorithm is faster than that of the LSVM algorithm and the descent algorithm when solving large-scale nonlinear classification problems and thus it provides a feasible method for solving SVM. [ABSTRACT FROM AUTHOR]

This paper proposed a nonmonotonic trust region algorithm for solving inverse quadratic programming problems. It transformed the inverse quadratic programming problem into its dual problem which had a relatively small number of decision variables. Then it transformed the sub-problem into unconstrained optimization problem by using the general augmented Lagrange method. Numerical experiments show that the proposed algorithm runs faster than Newton algorithm and alternating direction method with Gaussian back substitution, it is more effective for large scale quadratic programming problems. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the clinical effects of percutaneous pedicle screw fixation(PPSF) combined with percutaneous vertebroplasty(PVP) for the treatment of osteoporotic thoracolumbar fractures., Methods: The clinical data of 94 patients with osteoporotic thoracolumbar fractures treated from January 2014 to December 2015 were retrospectively analyzed. There were 31 males and 63 females, aged from 65 to 70 years old with an average of 67.2 years. Fracture level was T₁₁ on 15 cases, T₁₂ on 32 cases, L₁ on 29 cases and L₂ on 18 cases. The patients were divided into two groups according to different therapeutic methods. Percutaneous pedicle screw fixation combined with percutaneous vertebroplasty were applied in 43 patients(group A) and percutaneous vertebroplasty was applied to 51 patients(group B). Operation time, intraoperative blood loss, bone cement volume, postoperative in-bed time were recorded; preoperatively, 3 d, 1 year after the operation, the ratios of anterior border heights, sagittal Cobb angles, visual analogue scale(VAS) scores were compared between two groups. The condition of postoperative complication in two groups was analyzed., Results: All the patients were followed up for 12 to 24 months with an average of 18.5 months. Operation time of group A [(96.2±28.7) min] was longer than that of group B [(31.8±10.6) min]. Intraoperative blood loss of group A[(62.2±25.5) ml] was more than that of group B [(25.4±10.9) ml]. Bone cement volume of group A [(5.5±0.5) ml] was larger than that of group B [(4.9±1.1) ml]. Postoperative in-bed time of group A[(5.1±1.8) d] was longer than that of group B[(1.8±0.7) d]. There were significant differences in operation time, intraoperative blood loss, bone cement volume, postoperative in-bed time between two groups( P <0.05). Three days, 12 months after the operation, the ratios of anterior border heights and Cobb angles in two groups were significantly improved. At final follow-up, the ratio of anterior border height and Cobb angle of group A[(85.6±3.5)%, (11.9±5.3)°] were better than of group B[(84.2±4.5)%, (15.3±3.4)°]( P <0.05). Three cases in group B had re-collapse of cemented vertebral bodies. Postoperative at 3 d, 1 year, VAS score of all patients had significantly decreased( P <0.05), and there was no significant difference between two groups( P >0.05)., Conclusions: Compared to simple PVP, PPSF combined with PVP in treating osteoporotic thoracolumbar fracture can obtain stronger vertebral strength and stiffness, furthermore to improve vertebral reduced effect, keeping vertebral heights, and preventing vertebral re-collapse., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© 2018 by the China Journal of Orthopaedics and Traumatology Press.)

Objective: To evaluate the bone regenerative potential of recombinant human bone morphogenetic protein 2(rhBMP-2)/collagen on adult rat calvarial bone., Methods: A tight subperiosteal pocket was produced under both sides of the temporal muscle in rats. rhBMP-2/collagen was implanted in one side and collagen alone was implanted in the other side as control. The rats were sacrificed 2, 4 and 8 weeks after operation. The specimen was harvested and examined histologically. For morphometric analysis, the thickness of the temporal bone of both sides was measured and compared., Results: The rhBMP-2/collagen onlay implant resulted in active bone formation and the augmented bone was connected directly with the original bone, whereas the collagen alone resulted in neither bone nor cartilage production. The ossification process in the rhBMP-2/collagen occurred directly through bone formation, similar to intramembranous ossification., Conclusion: rhBMP-2/collagen is an effective material as a biological onlay implant.