Papers by Author: Kun Shang

Abstract: This paper has explored the design of three-dimensional imaging sonar software and its application to the hardware platform. In the process of designing, the software has been optimized in view of characteristics of the hardware structures and calculation of the TMS320C6416, and the specific optimization methods and effects have also been presented. It turns out that the effect of software optimization is obvious and the working system stable and reliable.

Abstract: Deadlock is a common problem in concurrent processing where two or more processes compete for resources in mutually exclusive way to access critical resources. The in-depth analysis and discussion about deadlock would be conducive to the improvement of reliability of the operating system. In this paper, problems about deadlock is analyzed and overviewed, including concept, cause of the deadlock, and prevention, avoidance , detection, and recovery from deadlock, etc .

Abstract: Real-Time operating systems not only request the logical correctness, but also request the correct computing results in a set time and the instant response to the real-time tasks. Therefore scheduling algorithms of real-time operating systems become an important measure to determine the real-time capability of a system. In this paper, we discuss the dynamic priority scheduling algorithm –Priority Inheritance Scheduling Algorithm. Then we analyze the algorithm from two aspects: description and schedulability.

Abstract: This paper is mainly concerned about the theoretical argument from Software design, which is based on underwater acoustic remote-control communication system of low-power signal chips and the simulation study on its core algorithms and its implementation on hardware system. Each command needs 125ns to be executed, while the master frequency of this filter is 8MHz, so it cannot deal with the signal processing synchronously. This process can only start after all the code elements are stored, which takes 2 seconds. However, the filter is so economic in energy that this micro-power system is endowed with a broad prospect in remote-control application, where the demand for synchronicity is not high.

Abstract: The basic test of the phased-array Doppler sonar velocity system made by us indicates that the positioning errors are large. From the positioning result, it can be known that compass error is the dominant factor. Therefore, to improve the measurement precision of compass and revise its course deviation is one of the keys to improve the accuracy of Doppler positioning. From the speed processing result, it shows that the positioning accuracy can be further improved through averaging the speed (smoothing).

Abstract: Congestion is an important issue in the research of end-to-end congestion control. The congestion issue in transmission with TCP is studied. Under the situation of different round trip time and multiple congested gateways, ECC (Explicit Congestion Control) algorithm is proposed to solve the congestion problem of TCP. The basic idea is to explicitly improve Congestion by adding mechanism at both end systems and gateways. Then study the tile congestion of Internet data transmission. Internet data transmission relies on end system mechanisms to keep Congestion. As the number of the users has been very large, this scheme has become vulnerable. It is required to deploy some congestion mechanism at gateways.