一个基于RTP/RTCP的手机报警系统

在研究RTP/RTCP协议特点与功能的基础上,讨论了基于RTP/RTCP协议实时视频传输的控制方法。通过此控制方法可以有效地提高RTP流的平稳性,减小抖动,增加网络带宽的利用率,流畅地传输多媒体数据。利用GPS、RTP/RTCP等协议实现了手机报警系统。     

Consistency,Turing Computability and Gödel’s First Incompleteness Theorem

It is well understood and appreciated that Gödel’s Incompleteness Theorems apply to sufficiently strong, formal deductive systems. In particular, the theorems apply to systems which are adequate for conventional number theory. Less well known is that there exist algorithms which can be applied to such a system to generate a gödel-sentence for that system. Although the generation of a sentence is not equivalent to proving its truth, the present paper argues that the existence of these algorithms, when conjoined with Gödel’s results and accepted theorems of recursion theory, does provide the basis for an apparent paradox. The difficulty arises when such an algorithm is embedded within a computer program of sufficient arithmetic power. The required computer program (an AI system) is described herein, and the paradox is derived. A solution to the paradox is proposed, which, it is argued, illuminates the truth status of axioms in formal models of programs and Turing machines.     

Performance of the MAP/G/1 Queue Under the Dyadic Control of Workload and Server Idleness

This paper studies the steady-state queue length process of the MAP/G/1 queue under the dyadic control of the D-policy and multiple server vacations. We derive the probability generating function of the queue length and the mean queue length. We then present computational experiences and compare the MAP queue with the Poisson queue.

‘Podracing’: experimenting with mobile TV content consumption and delivery methods

Recently, mobile TV has been launched in several countries. While mobile TV integrates television contents into mobile phones, the most personal of communication devices, it becomes interesting to know how this feature will be used throughout the day and in varying contexts of everyday life. This paper presents empirical results on the use of mobile TV with different delivery mechanisms and both quantitative and qualitative results on how end-users prefer to use mobile TV contents in different situations. The data is based on ongoing empirical research in Finland in 2006 and 2007. The mobile TV services under study included both news and entertainment contents, and were tested in 3G, DVB-H and Wi-Fi networks using different delivery paradigms: broadcast, on-demand and download. To explore the use of different delivery methods and content consumption, we have developed a mobile TV service protoype, called Podracing. The analysis shows that users appreciated up-to-date information and information-rich media forms and contents especially for mobile news delivery. There was high demand for only the latest news on mobiles. The real-time property was considered important. Most of the users looked at the headlines or followed the news several times a day – much more often than the traditional TV and news prime times would allow.     

浅析3G技术及发展策略

本文简述3G（第三代移动通信系统）的含义及3G技术的基本特点;从3G技术在通信类业务、娱乐类业务、资讯类业务、互联网业务等方面的应用,介绍其发展现状;分析3G技术在培育用户、建立行业联盟、建设流媒体平台、提高内容质量方面的发展策略。     

基于ARM7处理器的μC／OS—Ⅱ移植

在深入分析μC／OS-Ⅱ移植的基础上,提出了一种新的μC／OS-Ⅱ移植方法。该方法的特点是：将任务的缺省模式设计为用户模式,并且任务级的任务切换OS_TASK_SW（）采用ARM处理器的软中断指令SWI来实现。     

基于3G终端的双处理器间通信模块设计

在现在的手机终端中,由于视频、音频的编解码需要占用大量的CPU时间,因此在3G终端中再增加一个CPU来进行多媒体信息的处理成为必然,通过主CPU上运行多媒体块所要解决的核心问题.通过主从CPU之间约定特定的消息来实现主CPU对从CUP的控制,而从CPU对主CPU的定时和携带数据满住固定大小这两种反馈机制有效解决了双CPU间的通讯问题.     

智能设备基于J2ME平台的3D开发技术

在PC机的3D和智能设备应用上,碰撞检测始终是程序开发的难点,甚至可以用碰撞检测作为衡量3D引擎是否完善的标准。现有许多3D碰撞检测算法,其中AABB碰撞检测是一种卓有成效而又经典的检测算法,本文详细论述了AABB碰撞检测的技术。     

GARMIN1000航空电子系统原理及维护方法

Garmin1000系统（以下简称G1000系统）是Garmin公司生产的,集成了通讯、导航、GPS等航空电子设备并配备大屏幕、高分辨率的显示器的一套综合航空电子系统。现已广泛应用于各类通用航空飞机上。为了更好地使用和维护好该系统,本文重点介绍其原理、结构、功能和主要维护方法。     

第三代移动通信三大标准浅析

本文介绍了第三代移动通讯的三大标准及其技术特点。并从技术、商用两个角度做出横向对比分析．阐述了各自的优势与缺欠。