Papers by Author: Jun Er Ma

Abstract: We gradually improve the shape of cans by using geometry, derivative and programming knowledge. Firstly suppose the shape of cans is a circular cylinder and both of the thickness of the side and under bottom of it are b, the thickness of the upper bottom is . Then establish a Binary function’s extreme problem with a condition, through the programming we finally get the optimal design for which the ratio of Radius r and Height h is 1:(1+ ).Secondly, design the cans is a connection of circular cylinder and frustum of a cone, the thickness of the surface is like the same assumptions as before, establish a multi-function’s extreme problem with a condition, through the programming we can get the optimum design size.

Abstract: The paper aims at improving students’ comprehensive qualities through mathematical model teaching and practice. The students can acquire better innovative and data-processing capacity. This paper clearly states that in mathematical model teaching, theory should be combined with practice to stimulate students’ thirst for knowledge, and proper cases should be chosen according to different majors, thus improving student’s application ability of mathematics and computers.

Abstract: In this note, a class of gun control system of tank is considered with all uncertainties, such as unknown constant parameters, unlinearly parts, unparameterized parts, unmodeled parts, unknown external disturbance and so on. An robust adaptive control law is designed with backstepping technique. Compared to exist results on tank gun control problem , our control scheme combine the robust control and the adaptive estimator of unknown constant parameters and can compensate all uncertainties Accurately. The stability of closed loop system and the tracking performance can be guaranteed by this control law. Simulation studies show that this controller is effective.

Abstract: When the observation station and the satellite or the spaceship are coplanar, the earth can be approximated into an uniform sphere. By applying the sine rule of plane geometry, the orbit arc length can be calculated which each observation station can measure. Numbers of observation stations should at least be established can be calculated by using the ratio method. When the earth’s self-rotation is taken into account, we can calculate the fewest numbers of observation stations by calculating the area of spherical surface that each station can observe and combining the division of regular hexagon of a football. In the end, the article analyzes the related material of ShenZhou V and the period of time of each station.

Abstract: In order to improve the low thermal efficiency of Solar Energy Fission Geyser, a VV modulation control system of circulating pump based on fuzzy control has been designed. In this system, SCM P89LPC930 is the core. A digital temperature sensor of 1-wire bus LTM8871 is used to detect the real-time temperature and an inner comparator of P89LPC930 to detect the zero point. According to fuzzy control rules, a best angle is chosen. This technology is applied to drive the AC motor to get constant temperature differential. The system is effective in improving the thermal efficiency and poor circulation by avoiding frequent start-up of circulation pump. The innovation points lie in the system uses a minimum hardware circuit design and fuzzy control, with easy circuit, reliable performance characteristics, thus having a high application value.