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动态公式模型法在计算机辅助工时定额计算中的应用 被引量:3
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作者 任治军 徐开清 贺仁华 《机电工程技术》 2012年第2期5-9,共5页
受加工方法、使用设备、材料、加工精度及切削参数等不同因素的影响,工时定额的计算公式变得极其繁杂,在很大程度上制约了计算机辅助工时定额的应用。为了灵活快捷地进行工时定额计算公式的定义、扩充和修改,提出了动态公式模型法,以公... 受加工方法、使用设备、材料、加工精度及切削参数等不同因素的影响,工时定额的计算公式变得极其繁杂,在很大程度上制约了计算机辅助工时定额的应用。为了灵活快捷地进行工时定额计算公式的定义、扩充和修改,提出了动态公式模型法,以公式表达式和公式参数说明来表示计算公式,以变"多维表"为"一维字符串"的方式来表示公式选择条件和公式中的查表参数信息,实现了固定模式下不同计算公式的表达和定义,并结合数据库技术建立了工时定额的计算模型及工时定额公式库,成功地运用到某企业的计算机辅助工时定额系统中,通过应用证明,具有良好的实用性和扩展性。 展开更多
关键词 计算机辅助工时定额 动态公式模型 表达式解析
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Alternate Form of Damped Wave Conduction and Relaxation Equation a Capite Adcalcem in Temperature
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作者 Kal Renganathan Sharma 《Journal of Physical Science and Application》 2013年第1期46-53,共8页
An alternate non-Fourier heat conduction equation is derived from consideration of translation motion of spinless electron under a driving force due to an applied temperature gradient. This equation is a eapite ad cal... An alternate non-Fourier heat conduction equation is derived from consideration of translation motion of spinless electron under a driving force due to an applied temperature gradient. This equation is a eapite ad calcem,temperature. Elimination of the rate of change of velocity with respect to time leads to a non-Fourier heat conduction equation with a accumulation of temperature or ballistic term in it. The new constitutive heat conduction equation is combined with the energy balance equation in one dimension. The governing equation for transient temperature a partial differential equation (Eq. (23)) is solved for by the method of Laplace transforms. The problem considered is the semi-infinite medium with constant thermo physical properties with constant wall temperature boundary condition. A closed form analyticalexpression for the transient temperature was obtained (Eq. (36)) after truncation of higher order terms in the infinite binomial series and use of convolution and lag properties. This solution is compared with that obtained using the parabolic Fourier model and the damped wave model as presented in an earlier study. The predictions of Eq. (36) are closer to the Fourier model. The convex nature of the temperature curve is present. 展开更多
关键词 Transport theory non-fourier conduction CWT constant wall temperature binomial infinite series.
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