基于ADSP2187的HDTV音频编码器系统

设计并实现了基于ADSP2187处理器的高清晰度电视信源编码系统中的音频编码器。编码器由实时编码和PES打包构成，实时编码完成立体声数字音频的编码压缩，压缩的码流符合ISO／IEClll83-3MPEG-2标准，同时还接收Dblby AC—3ES流输入。PES打包完成MPEG-2与AC-3ES流的PES打包。文中阐述了编码器的工作原理及设计思想，描述了该编码器硬件系统结构，分析了硬件设计的时序。     

Design, Architecture and Performance Evaluation of the Wireless Transport Layer Security

Communication protocols for wireless networks have specified security layers, with high-level encryption strength. The dedicated to security layer of Wireless Application Protocol (WAP), is the Wireless Transport Layer Security (WTLS). In this paper, an efficient architecture for the hardware implementation of WTLS is proposed. The introduced system supports bulk encryption, authentication and data integrity. The proposed architecture operates alternatively for a set of ciphers, IDEA, DES, RSA, D.H., SHA-1 and MD5. It is based on two reconfigurable design units: the Reconfigurable Authentication Unit and the Reconfigurable Integrity Unit. These units operate alternatively for different ciphers and achieve to allocate minimized resources, at the same time. The introduced security system has been implemented in an FPGA device. The supported ciphers performance is compared with previously published works, and it has been proven superior to them, in most of the cases. The system’s synthesis results prove that the proposed architecture is a flexible and powerful solution for WTLS integration of today’s and future wireless networks. The system can be applied to wireless communications servers and mobile devices also. Finally, the proposed architecture can be used as a powerful security engine, in WAP communication networks, with special security demands.     

Support for real-time decision making in mobile financial applications

Mobile users making real-time decisions based on current information need confidence that their context has been taken into consideration in producing the system’s recommendations. This chapter reviews current use of mobile technologies for context-aware real-time decision support. Specifically, it describes a framework for assessing the impact of mobility in decision making. The framework uses dynamic context model of data quality to represent uncertainties in the mobile decision-making environment. This framework can be used for developing visual interactive displays for communicating to the user relevant changes in data quality when working in mobile environments. As an illustration, this chapter proposes a real-time decision support procedure for on-the-spot assistance to the mobile consumer when choosing the best payment option to efficiently manage their budget. The proposed procedure is based on multi-attribute decision analysis, scenario reasoning, and a quality of data framework. The feasibility of the approach is demonstrated with a mobile decision-support system prototype implementation. This article is part of the “Handbook on Decision Support Systems” edited by Frada Burstein and Clyde W. Holsapple (2008) Springer.     

Real-time reliability prediction for dynamic systems with both deteriorating and unreliable components

As an important technology for predictive maintenance, failure prognosis has attracted more and more attentions in recent years. Real-time reliability prediction is one effective solution to failure prognosis. Considering a dynamic system that is composed of normal, deteriorating and unreliable components, this paper proposes an integrated approach to perform real-time reliability prediction for such a class of systems. For a deteriorating component, the degradation is modeled by a time-varying fault process which is a linear or approximately linear function of time. The behavior of an unreliable component is described by a random variable which has two possible values corresponding to the operating and malfunction conditions of this component. The whole proposed approach contains three algorithms. A modified interacting multiple model particle filter is adopted to estimate the dynamic system’s state variables and the unmeasurable time-varying fault. An exponential smoothing algorithm named the Holt’s method is used to predict the fault process. In the end, the system’s reliability is predicted in real time by use of the Monte Carlo strategy. The proposed approach can effectively predict the impending failure of a dynamic system, which is verified by computer simulations based on a three-vessel water tank system.     

Prototype of fault adaptive embedded software for large-scale real-time systems

This paper describes a comprehensive prototype of large-scale fault adaptive embedded software developed for the proposed Fermilab BTeV high energy physics experiment. Lightweight self-optimizing agents embedded within Level 1 of the prototype are responsible for proactive and reactive monitoring and mitigation based on specified layers of competence. The agents are self-protecting, detecting cascading failures using a distributed approach. Adaptive, reconfigurable, and mobile objects for reliablility are designed to be self-configuring to adapt automatically to dynamically changing environments. These objects provide a self-healing layer with the ability to discover, diagnose, and react to discontinuities in real-time processing. A generic modeling environment was developed to facilitate design and implementation of hardware resource specifications, application data flow, and failure mitigation strategies. Level 1 of the planned BTeV trigger system alone will consist of 2500 DSPs, so the number of components and intractable fault scenarios involved make it impossible to design an ‘expert system’ that applies traditional centralized mitigative strategies based on rules capturing every possible system state. Instead, a distributed reactive approach is implemented using the tools and methodologies developed by the Real-Time Embedded Systems group.     

Real-time behavior-based robot control

Behavior-based systems form the basis of autonomous control for many robots, but there is a need to ensure these systems respond in a timely manner. Unexpected latency can adversely affect the quality of an autonomous system’s operations, which in turn can affect lives and property in the real-world. A robots ability to detect and handle external events is paramount to providing safe and dependable operation. This paper presents a concurrent version of a behavior-based system called the Real-Time Unified Behavior Framework, which establishes a responsive basis of behavior-based control that does not bind the system developer to any single behavior hierarchy. The concurrent design of the framework is based on modern software engineering principles and only specifies a functional interface for components, leaving the implementation details to the developers. In addition, the individual behaviors are executed by a real-time scheduler, guaranteeing the responsiveness of routines that are critical to the autonomous system’s safe operation. Experimental results demonstrate the ability of this approach to provide predictable temporal operation, independent of fluctuations in high-level computational loads.     

一种基于多重索引的大规模数据快速查找算法

在手持式设备移动计算中,为了实时获取信息,往往需要对数据进行高效查找,而这又与手持式设备较弱的计算处理功能相矛盾.从硬件体系与软件算法综合考虑角度出发,提出了一种基于大规模记录的索引快速查找算法.实践表明,该算法结合所设计的多层次硬件体系,能高效地实现数据快速定位查找.     

Human face detection with neural networks and the DIRECT algorithm

Based on Rowley’s approach, this article proposes a new architecture that uses a specific optimization technique, the DIRECT (DIviding RECTangle) algorithm, to improve the efficiency of face detection in images. The system consists of two main parts: a neural network-based face detection arbitrator, and a search strategy based on an integer-handling DIRECT algorithm. By the architecture, the number of arbitrations is dramatically reduced, and human faces, if they are present in an image, are not restricted to predetermined resolutions and aspect ratios. Experimental results show that the proposed architecture is efficient in terms of both speed and robustness. This work was presented in part at the 12th International Symposium on Artificial Life and Robotics, Oita, Japan, January 25–27, 2007     

一种适用于MPEG-4形状编码的快速运动估计算法

运动估计是MPEG-4形状编码的一项关键技术,本文提出了一种适用于形状编码的快速运动估计算法。算法首先在参考帧中进行扫描,得出视频对象的二值边界掩模;在匹配运算时使用lbit的异或运算代替原有的加法运算;设定有效的中止准则,对于静止点直接中止搜索;在搜索过程中采用了渐进消除算法,能够在不影响搜索精度的前提下减少搜索点。实验结果表明使用本文的快速搜索算法,运动估计中的运算量比MPEG-4 VM原有搜索算法有较大幅度的降低,且编码后的码字长度与原算法基本一致。     

Drift-Free Real-Time Sequential Mosaicing

We present a sequential mosaicing algorithm for a calibrated rotating camera which can for the first time build drift-free, consistent spherical mosaics in real-time, automatically and seamlessly even when previously viewed parts of the scene are re-visited. Our mosaic is composed of elastic triangular tiles attached to a backbone map of feature directions over the unit sphere built using a sequential EKF SLAM (Extend Kalman Filter Simultaneous Localization And Mapping) approach. This method represents a significant advance on previous mosaicing techniques which either require off-line optimization or which work in real-time but use local alignment of nearby images and ultimately drift. We demonstrate the system’s real-time performance with real-time mosaicing results from sequences with 360 degrees pan. The system shows good global mosaicing ability despite the challenging conditions: hand-held simple low-resolution webcam, varying natural outdoor illumination, and people moving in the scene.     

Distributing emotional services in Ambient Intelligence through cognitive agents

Ambient Intelligence (AmI) is a pervasive computing paradigm whose main aim is to design smart environments composed of invisible, connected, intelligent and interactive systems, which are naturally sensitive and responsive to the presence of people, providing advanced services for improving the quality of life. Nevertheless, AmI systems are more than a simple integration among computer technologies; indeed, their design can strongly depend upon psychology and social sciences aspects describing, analysing and forecasting the human being status during the system’s decision making. This paper introduces a novel methodology for AmI systems designing that exploits a service-oriented architecture whose functionalities are performed by a collection of so-called cognitive agents. These agents exploit a novel extension of Fuzzy Cognitive Maps benefiting on the theory of Timed Automata and a formal method for representing human moods in order to distribute emotional services able to enhance users’ comfort and simplify the human/systems interactions. As will be shown in experimental results, where a usability study and a confirmation of expectations test have been performed, the proposed approach maximizes the system’s usability in terms of efficiency, accuracy and emotional response.     

A real-time fuzzy reasoning based control system for catching a moving goldfish

Designing a real-time visual tracking system to catch a goldfish is a complex task because of the large amount of streaming video data that must be transmitted and processed immediately when tracking the goldfish. Usually, building such visual servoing systems requires the application of high-cost specialized hardware and the development of complicated visual control software. In this paper, a novel low-cost, real-time visual servo control system is presented. The system uses stereo vision consisting of two calibrated cameras to acquire images of the goldfish, and applies the continuously adaptive mean shift (CAMSHIFT) vision-tracking algorithm to provide feedback of a fish’s real-time position at a high frame rate. It then employs a 5-axis robot manipulator controlled by a fuzzy reasoning system to catch the fish. This visual tracking and servoing system is less sensitive to lighting influences and thus performs more efficiently. Experiments with the proposed method yielded very good results, as the system’s real-time 3D vision successfully tracked two fish and guided the manipulator, which has a net attached to its end effector, to catch one of them.     

嵌入式MPEG4视频服务器的设计与实现

介绍了基于Linux操作系统和MPEG 4硬件实时编码器的嵌入式视频服务器(EMP4VS)的设计,并从硬件组成、软件设计、控制/视频数据流图、视频图像网络传输中的QoS机制和客户端几个方面介绍了具体的实现方法。并对利用中间件服务器扩展EMP4VS监控系统的方案进行了讨论。