基于自适应遗传算法的模拟电路的电路级综合

利用准精确惩罚函数法构造出价格函数,并且采用自适应遗传算法,进行电路级综合,以获得全局最优解。实验结果表明:利用本方法可以快速设计出满足性能指标的CMOS运算放大器。     

Robust adaptive controller design for a class of nonlinear systems with unknown high frequency gains

INTRODUCTIONMany researchers have devoted their energy to the development of nonlinear system with unknown control directions during the past few years. The class of nonlinear system has been developed greatly since Mudgett and Morse (1985) relaxed the assumption that the unknown multiplicative terms are not only sign-invariant but also have known signs. A method called correction vector approach was proposed in (Lozano et al., 1990) and has been applied to design adaptive controller of …     

一类非线性时滞系统的鲁棒自适应控制

针对一类含有非线性参数的非线性时滞系统．利用参数分离技术和后推方法,提出了一种自适应状态反馈控制方案,保证闭环系统的所有信号全局一致有界。通过构造Lyapunov—Krasoviskii泛函证明了系统的状态能收敛到零的一个小邻域内。     

An embedded packet train and adaptive FEC scheme for effective video adaptation over wireless broadband networks

INTRODUCTION With the emergence of wireless technology, various multimedia services, e.g., audio and/or video, are reaching us today through portable devices any- time, anywhere and even more increasingly accessi- ble in the near future. High quality video streaming over wireless IP is one of the most attractive applica- tions by ongoing deployment of wireless local area network (WLAN) hotspots and even powerful Wi- MAX mobile coverage. However, the present Internet is not providing a…     

Research on fast real-time adaptive audio mixing in multimedia conference

INTRODUCTION As one of the main applications in Packet-based network (PBN) environment, multimedia communi-cation is developing rapidly, with many service pro-viders starting to offer new services. Audio interactive operation is one of the most basic components in multimedia conference. Because of absence of QoS mechanism in most application environments of PBN, network blocking will cause problems such as data loss and audio jitter in end-to-end communication (Yang et al., 2001). Th…     

自助借还书系统中的多书侦测研究

对所借图书进行多书侦测研究,可尽量减少自助式借还书过程中的违规操作,设计一种工作于可见光波段的多书侦测系统。该系统利用摄像装置跟踪被借还图书,提取并分析图书侧面图以判断是否存在违规操作。系统能够自适应地进行图书侧面的识别和提取,具有良好的侦测借还书过程中违规行为的能力。     

An adaptive FEC to protect RoHC and UDP-Lite H.264 video critical data

INTRODUCTION Recommendation H.264 was approved by ITU-T in May 2003 and the approved draft specifi cation is available for public review (Wiegand, 2003) The H.264 video codec has a very broad application range that covers all forms of digital compressed video from low bit rate Internet streaming applica tions to HDTV broadcast and digital cinema applica tions with near lossless coding. About 50% band width would be saved by using H.264 when compared to the existing most efficient com…     

一个基于WEB的自主学习系统模型

智能教学系统是计算机的一个重要应用领域。本文描述了一个基于Web的自主学习系统模型,着重介绍了系统的基本功能和主要特点。该系统吸取当前智能教学系统相关研究中较为成熟的技术给予实现,集成了教学、自学、自测、智能反馈等功能。     

Profile of South African secondary-school teachers’ teaching quality: evaluation of teaching practices using an observation instrument

The need for quality teaching is reflected in the poor performance of students in international tests. Teachers’ practices and contextual factors could contribute to substandard quality of teaching in South Africa. Several studies indicate that successful learning is largely dependent on the teachers’ practices in class. The focus of the present research was to profile the effective teaching practices of 424 secondary-school teachers in the Gauteng Province, South Africa. Teachers were observed by trained observers using a valid and reliable observation instrument measuring six domains of effective teaching practices. Results showed that teachers find it difficult to differentiate in class and to activate learning. Additionally, teachers with more than 15 years of teaching experience scored lower than teachers with less experience, in all six teaching domains. Presumably, experienced teachers may lack motivation and/or insufficient training in implementing interactive and differentiated teaching methods that are needed for effective teaching practices.     

Adaptively selecting biology questions generated from a semantic network

The paper describes a biology tutoring system with adaptive question selection. Questions were selected for presentation to the student based on their utilities, which were estimated from the chance that the student’s competence would increase if the questions were asked. Competence was represented by the probability of mastery of a set of biology knowledge components. Tasks were represented and selected based on which knowledge components they addressed. Unlike earlier work, where the knowledge components and their relationships to the questions were defined by domain experts, this project demonstrated that the knowledge components, questions and their relationships could all be generated from a semantic network. An experiment found that students using our adaptive question selection had reliably larger learning gains than students who received questions in a mal-adaptive order.