水压节流阀口流量特性的实验研究及水压节流阀的研制

本文将介绍作者自行研制的水压阀阀口流动特性的实验装置，用该装置完成了各种典型水压阀阀口流动特性以及空化影响流动特性的实验研究，依据实验的结果完成了水压元件性能试验台所需各类水压阀的研制。     

基于混合遗传算法的去耦电容网络设计

结合基于目标阻抗的设计方法,将混合遗传算法应用于PDN(电源分配网络)的去耦电容网络设计,对所需去耦电容器的种类和数目进行优化计算,同时与标准遗传算法和传统设计方法进行对比,借助Cadence电源完整性仿真工具验证设计结果的有效性和合理性。避免了传统设计需要借助EDA工具进行反复修改和验证的繁琐过程,同时减少了设计冗余,节省了PCB布局布线空间,为高频电路的PDN设计提供参考。     

3G移动通信系统的无线网络优化论述

近些年来,我国的移动通信业务的规模不断的扩大,移动通信的形式也不断的发展,3G技术已经实现了推广和运行,这种情况下优化无线网络运营环境,实现3G移动通信网络的系统技术升级,就是未来通信行业发展所要面临的最主要的问题.     

Detecting Driver Normal and Emergency Lane-Changing Intentions With Queuing Network-Based Driver Models

Driver intention detection is an important component in human-centric driver assistance systems. This article proposes a novel method for detecting driver normal and emergency left- or right-lane-changing intentions by using driver models based on the queuing network cognitive architecture. Driver lane-changing and lane-keeping models are developed and used to simulate driver behavior data associated with 5 kinds of intentions (i.e., normal and emergency left- or right-lane-changing and lane-keeping intentions). The differences between 5 sets of simulated behavior data and the collected actual behavior data are computed, and the intention associated with the smallest difference is determined as the detection outcome. The experimental results from 14 drivers in a driving simulator show that the method can detect normal and emergency lane-changing intentions within 0.325 s and 0.268 s of the steering maneuver onset, respectively, with high accuracy (98.27% for normal lane changes and 90.98% for emergency lane changes) and low false alarm rate (0.294%).     

Performance analysis on Lv distribution and its applications

A new signal analysis method, known as Lv distribution (LVD), has been reported recently to provide improved estimation accuracy of centroid frequency and chirp rate. In this paper, performances of the LVD on signal concentration, detection, representation errors and computational complexity are discussed and compared with polynomial Fourier transform (PFT) and fractional Fourier transform (FrFT). Based on the results of our theoretical analysis and Monte Carlo simulations, it is shown that the LVD achieves desirable performance improvement compared with those achieved by other methods. By using the accurate estimation of chirp rate provided by the LVD, the performance of local polynomial periodogram (LPP) is investigated. Comparisons with other time–frequency representations, such as the inverse LVD (ILVD) and the PFT-based LPP, are made on signal concentration in the time–frequency domain.     

A Stochastic Vehicle Routing Problem with Travel Time Uncertainty: Trade-Off Between Cost and Customer Service

On-time shipment delivery is critical for just-in-time production and quick response logistics. Due to uncertainties in travel and service times, on-time arrival probability of vehicles at customer locations can not be ensured. Therefore, on-time shipment delivery is a challenging job for carriers in congested road networks. In this paper, such on-time shipment delivery problems are formulated as a stochastic vehicle routing problem with soft time windows under travel and service time uncertainties. A new stochastic programming model is proposed to minimize carrier’s total cost, while guaranteeing a minimum on-time arrival probability at each customer location. The aim of this model is to find a good trade-off between carrier’s total cost and customer service level. To solve the proposed model, an iterated tabu search heuristic algorithm was developed, incorporating a route reduction mechanism. A discrete approximation method is proposed for generating arrival time distributions of vehicles in the presence of time windows. Several numerical examples were conducted to demonstrate the applicability of the proposed model and solution algorithm.     

石头口门水库洪水调度系统效益分析

石头口门水库洪水调度系统提高了洪水预报精度,增强了水库的安全性,提高了水库的综合效益。通过定性分析和定量计算,分析了石头口门水库洪水调度系统所创造的防洪效益、兴利效益用及社会效益。并根据水库工程现状,提出如何最大限度的发挥石头口门洪水调度系统的综合效益。     

PLC在老虎潭引水工程加压系统中的应用

目前大多数引水工程建设,远距离输水需要中途加压,才能使水源满足城市供水要求,为此采用PLC,使控制程序既具有处理复杂逻辑控制的能力,又具有方便修改流程参数的能力。在分析具体监测系统控制流程的基础上,介绍了利用PLC的梯形图编程进行逻辑控制的方法,给出了程序原理图,讨论了温度保护、变频调速控制、数据采集和处理等主要问题的处理方法。具体应用说明采用PLC通过编写梯形图进行引水工程加压控制,可有效地提高加压系统的工作效率。     

网络攻击的防范策略

近年来计算机网络受到攻击及瘫痪的现象频频发生,给企业和社会造成极大的经济损失,在社会上影响极坏。因此,除了传统的预防方法之外,为改变这种被动受攻击的局面,本文对网络攻击的防范策略进行了探讨。     

基于单片机的地震仪器采集站控制优化

地震仪器是一种重要的油气勘探设备。在地震仪器中,由电源站为采集站提供电能,采集站的控制方案影响电源站的带道数量。为了提高电源站的带道数量,减少勘探成本,本文根据对地震仪器供电模型的分析,针对采集站启动状态对电源站带道数量的影响,提出了一套采集站单片机控制的优化方案,并进行了实验验证。实验结果表明,在55米道距时,电源站带道数量可提高至40道,优化方案切实、有效。