To simplified the designing, diagram presentation, construction and profile of helicoidal stair, the formation of helicoid is analyzed, and it's mathematical model is studied.
为简化旋转楼梯的设计、图示、施工及剖面形状，对螺旋面的形成进行了分析，建立了螺旋面的数学模型。
2
The proposed graphical method may directly plot the CAM profile without plotting its pitch curve, therefore its construction is more simplified and more accurate.
这种作图法可以直接求出凸轮的实际轮廓曲线而毋须绘制其理论轮廓线，因而使作图简化精确。
3
This article established displacement natural ventilation model caused by point heat source of two joined rooms. The room vertical temperature profile was simplified as two uniform zones.