This paper proposes an efficient implementation of digital up and down conversion for Software Defined Radio (SDR) using Model-Based Design (MBD). In particular, a novel flow for designing digital up and down conversion is detailed. Using MBD, a system model is at the center of the development process, from requirement development, through design, implementation, and testing. Using MBD, code can be automatically generated for system and create test benches for system verification, which is saving time and avoiding the introduction of manually coded errors. Design example shows that the proposed method can greatly reduce the complexity of digital up and down conversion while providing the efficient and reliability of design flow.

The relevant increase in the number of uncontrolled space debris is nowadays considered one of the main threats for future sustainability of space activities and space access. With the increase amount of space debris, space debris causes more widespread attention over the world. After analyzing the relationship between maneuvering energy, orbital transfer time and the orbital radius, a mathematical model has been established which can explain the mechanism of the space debris deorbit and improve the accuracy of orbit location. At the same time, a feedback decision-making system is proposed for choosing the best way to deorbit space debris though the analysis of the factors on the total cost.

In this paper, two

Aerobic exercise is a "young" and loved by people of sports, therefore, in recent years research on aerobics is numerous, this article is on the basis of predecessors' research on aerobics athlete training body posture is analyzed and studied, for the study of the action process of knee joint force analysis provide the image of the space analytic foundation; The two 2-dof rigid body dynamics model was established, for the action process of knee joint torque analysis provides a theoretical basis; Later in this paper, by applying a table in the form of more clearly show the differences between the two aerobics athletes, through the comparison we can draw on the differences between two aerobics athlete was more obvious, therefore, for 1 calisthenics athletes need to shoulder joint control in 65-degree is more appropriate, and sums up with the increase of the difficulty in the time-consuming, differences between two calisthenics athletes will be more and more obvious, at the same time reflects the calisthenics athletes 1 ability is prominent, through the comparison we found that the elbow of calisthenics athletes under than 1 2 aerobics athlete ability, therefore proves that the no. 1 aerobics athlete's comprehensive strength is strongest. Then by studying the aerobics athlete's habits are drawn in the Angle of minimum right knee joint position with a minimum right knee joint Angle position under the two positions when the joint Angle of the hour, the greater the moment will heavy torque, the greater the muscle torque will increase, the study will be the study of aerobics biomechanics analysis theory plays a certain role in promoting.