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81.
This work presents the findings of a study to quantify the relative effectiveness of the primer preseating operation in small caliber cartridge production. In theory, primer preseating would enable cartridge stamping tools to achieve deeper stamping penetration depths and subsequently, greater primer retention forces. This is because, with preseating incorporated in the existing small caliber cartridge production process, a cartridge stamping tool would be fully dedicated to performing the case stamping operation (rather than the simultaneous primer seating and case stamping operations it currently performs). The findings presented in this work include measured percentages of total stamping tool force dedicated to primer seating, stamping tool penetration depths with and without primer preseating and primer retention forces with and without primer preseating. These findings and their underlying principles were produced through a static force equilibrium analysis and finite element modeling and simulation studies. 相似文献
82.
针对传统日用化学品化学课程教学中存在的各种问题, 进行了调整教学内容、改进教学方法和改革考核方式等方面的改革。调动了学生的学习积极性, 促进了师生间的互动, 加强了学生对知识的掌握, 提高了学生应用知识的能力, 培养了学生的创新思维。 相似文献
83.
84.
We propose an algorithm for the global optimization of continuous minimax problems involving polynomials. The method can be
described as a discretization approach to the well known semi-infinite formulation of the problem. We proceed by approximating
the infinite number of constraints using tools and techniques from semidefinite programming. We then show that, under appropriate
conditions, the SDP approximation converges to the globally optimal solution of the problem. We also discuss the numerical
performance of the method on some test problems.
Financial support of EPSRC Grant GR/T02560/01 gratefully acknowledged. 相似文献
85.
P. Parpas B. Rustem V. Wieland S. Žaković 《Computational Optimization and Applications》2009,43(2):235-259
In this paper, we consider expected value, variance and worst–case optimization of nonlinear models. We present algorithms
for computing optimal expected value, and variance policies, based on iterative Taylor expansions. We establish convergence
and consider the relative merits of policies based on expected value optimization and worst–case robustness. The latter is
a minimax strategy and ensures optimal cover in view of the worst–case scenario(s) while the former is optimal expected performance
in a stochastic setting.
Both approaches are used with a small macroeconomic model to illustrate relative performance, robustness and trade-offs between
the alternative policies. 相似文献
86.
利用算子的谱理论及经典的不等式,讨论两类离散哈密顿系统,得出半退化型系统为强极限点型以及Dirac型系统为极限点型的一些判别准则. 相似文献
87.
We determine the general form of the potential of the problem of motion of a rigid body about a fixed point, which allows the angular velocity to remain permanently in a principal plane of inertia of the body. Explicit solution of the problem of motion is reduced to inversion of a single integral. A several-parameter generalization of the classical case due to Bobylev and Steklov is found. Special cases solvable in elliptic and ultraelliptic functions of time are discussed. 相似文献
88.
89.
给出指数2情形下阶数为2l_1~(r1)l_1~(r2)的高斯和的显式计算公式.证明方法直接利用Stickelberger理想分解定理,进而结果独立于其他指数2情形高斯和的结果而成立. 相似文献
90.