基于单片机的开关电源检测系统的研制

根据某军用雷达所用开关电源的要求,设计了一种安全可靠的开关电源检测系统。分别介绍了各个外部扩展模块的电路以及主要模块的驱动程序,最后分析了系统实时操作的实现,讨论了系统的资源分配,提出了驱动程序和操作系统的优化方案。该检测系统充分利用LCD附带的存储器,实现了缓存机制,提高了工作的安全性和实时性。投产后的使用表明,该检测系统运行稳定可靠。     

Predication based immune network for multimodal function optimization

For the problem of indeterminate direction of local search, lacking of efficient regulation mechanism between local search and global search and regenerating new antibodies randomly in the original optimization version of artificial immune network (opt-aiNet), this paper puts forward a novel predication based immune network (PiNet) to solve multimodal function optimization more efficiently, accurately and reliably. The algorithm mimics natural phenomenon in immune system such as clonal selection, affinity maturation, immune network, immune memory and immune predication. The proposed algorithm includes two main features with opt-aiNet. The information of antibodies in continuous generations is utilized to point out the direction of local search and to adjust the balance between local and global search. PiNet also employs memory cells to generate new antibodies with high affinities. Theory analysis and experiments on 10 widely used benchmark problems show that when compared with opt-aiNet method, PiNet algorithm is capable of improving search performance significantly in successful rate, convergence speed, search ability, solution quality and algorithm stability.     

Photolamination bonding for PMMA microfluidic chips

Finding out a rapid and reliable bonding method for plastic microfluidic chips with PCR functions is challenging for analytical chemistry and biochemistry. A rapid, reliable covalent bonding method is introduced for fabricating PMMA PCR biochips with long channels and thin walls. The bonding strength of ~5 MPa was obtained and bulk cohesive failure occurred during tensiling tests. Preliminary leaking tests indicate that photolamination bonding can be implemented readily in the fabrication of PMMA PCR biochips.     

无线传感器网络阀门检漏仪表的设计

针对流程工业设备阀门泄漏造成的能源损耗和环境污染等问题,设计了基于ZigBee无线传感器网络的用于检测阀门泄漏的仪表.该无线阀门检漏仪表通过超声波检测、温度检测、压力检测,实现对阀门泄漏在线连续的监控,自动记录和报告阀门泄漏的地点和时间.这样,企业就可以有效地集中资源进行维修,减少泄漏造成的能源浪费和环境污染,最终达到节能减排的效果.     

下一代互联网核心技术IPv6研究

深入研究下一代互联系网的核心技术IPv6,详细介绍了IPv6跟IPv4相比的优势,研究了IPv6中所采用的IPSec协议、认证机制、加密机制和密钥管理机制等安全机制,讨论了IPv6的应用策略,展望了IPv6的应用前景。     

测试软件启动口令的简单实现

介绍了一种基于LabWindowsCVI测试软件启动口令的实现方法。这种方法简单有效,具有一定的实际应用价值。同时,还对这一方法所存在的问题及解决办法作了阐述。     

An adaptive signal-to-noise ratio estimator in mobile communication channels

Representing the reception condition directly, signal-to-noise ratio (SNR) is an important parameter in mobile propagation channels, and therefore is widely used in system performance evaluations and adaptive applications. Hence, this paper puts forward a frequency domain SNR estimator in mobile communications, where we exploit the signal model with the band-limited fading channel and the additive white Gaussian noise. With the above model, the noise power spectrum density can be estimated from the periodogram of channel-plus-noise signals, subsequently leading to our SNR estimation. Moreover, in order to degrade the intrinsic spectrum leakage of fast Fourier transform in periodogram calculation, the leakage expression is derived analytically and then an adaptive process is proposed to make a tradeoff between leakage reduction and noise smoothing. We verify our algorithm by simulations and observe high accuracy in a wide range of velocities and SNRs. Additionally, unlike the conventional work, the proposed estimator is not strictly based on the assumption of specific Doppler spectral shapes except for the requirement of the band-limited channel, hence it is robust to general mobile channels.     

Observer design for nonlinear discrete‐time systems: Immersion and dynamic observer error linearization techniques

This paper focuses on the observer design for nonlinear discrete‐time systems by means of nonlinear observer canonical form. At first, sufficient and necessary conditions are obtained for a class of autonomous nonlinear discrete‐time systems to be immersible into higher dimensional observer canonical form. Then a method called dynamic observer error linearization is developed. By introducing a dynamic auxiliary system, the augmented system is shown to be locally equivalent to the generalized observer form, whose nonlinear terms contain auxiliary states and output of the system. A constructive algorithm is also provided to obtain the state coordinate transformation. These results are an extension of their counterparts of nonlinear continuous‐time systems to nonlinear discrete‐time systems (Syst. Control Lett. 1986; 7 :133–142; SIAM. J. Control Optim. 2003; 41 :1756–1778; Int. J. Control 2004; 77 :723–734; Automatica 2006; 42 :321–328; IEEE Trans. Automat. Control 2007; 52 :83–88; IEEE Trans. Automat. Control 2004; 49 :1746–1750; Automatica 2006; 42 :2195–2200; IEEE Trans. Automat. Control 1996; 41 :598–603; Syst. Control Lett. 1997; 31 :115–128). Copyright © 2009 John Wiley & Sons, Ltd.     

无线传感器网络LEACH协议性能分析

LEACH协议是专门应用于无线传感器网络的层次路由协议,在无线传感器网络路由协议中占有重要地位。本文采用理论分析与仿真实验相结合的方法,对LEACH协议的性能进行了深入研究,指出了LEACH协议路由算法的不足,明确了进一步对LEACH协议进行改进的方向。     

Elastic Routing Table with Provable Performance for Congestion Control in DHT Networks

Consistent hashing-based DHT networks have an inherent load balancing problem. The problem becomes more severe in heterogeneous networks with nonuniform and time-varying popular files. Existing DHT load balancing algorithms are mainly focused on the issues caused by node heterogeneity. To deal with skewed lookups, this paper presents an elastic routing table (ERT) mechanism for query load balancing, based on the observation that high-degree nodes tend to receive more traffic load. The mechanism allows each node to have a routing table of variable size corresponding to node capacities. The indegree and outdegree of the routing table can also be adjusted dynamically in response to the change of file popularity and network churn. Theoretical analysis proves that the routing table degree is bounded. The ERT mechanism facilitates locality-aware randomized query forwarding to further improve lookup efficiency. By relating query forwarding to a supermarket customer service model, we prove that a two-way randomized query forwarding policy should lead to an exponential improvement in query processing time over random walking. Simulation results demonstrate the effectiveness of the ERT mechanism and its related query forwarding policy for congestion and query load balancing. In comparison with existing "virtual-server”-based load balancing algorithms and other routing table control approaches, the ERT-based congestion control protocol yields significant improvement in query lookup efficiency.