Photonic radio frequency channelizers based on Kerr optical micro-combs

We review recent work on broadband RF channelizers based on integrated optical frequency Kerr micro-combs combined with passive micro-ring resonator filters,with microcombs having channel spacings of 200 and 49 GHz.This approach to realizing RF channelizers offers reduced complexity,size,and potential cost for a wide range of applications to microwave signal detection.     

商业区近距离交叉口交通组织设计研究

研究位于商业区近距离交叉口的交通流组织优化设计,对改善该区域的交通运行状况、提高车辆和行人安全、解决城市交通拥挤等问题具有重要意义．以长春市欧亚车百商业区近距离交叉口为例,通过交通参数的调查分析,结合其地理位置及商业功能,提出交通组织设计方案,并采用饱和度和延误两个参数进行改善前后的对比分析．     

基于交叉口渠化提高道路通行能力的方法

以长春市2007年四环路南环段（102国道-彩宇广场）临河街路口设计实例为依托,研究如何通过渠化交通提高平面交叉口通行能力;提出交通渠化的设计原则和适应条件,并对设计中应注意的问题进行探讨．     

高度综合化数字接收机高效处理方法研究与设计

创新性地提出多级数字信道化加数字下变频相结合的高效处理方法实现多功能综合处理.首先通过宽带信道化处理并配合数字下变频,实现对宽带无源侦察、雷达探测、通信、识别等功能大带宽信号处理,然后在通过第二级信道化对一级信道化的信道带宽进行进一步细划分,并配合数字下变频实现对窄带无源侦察以及导航功能小带宽信号处理.仿真结果表明,该方法可同时实现多种高度综合化功能处理,并可大幅降低滤波器的阶数和设计难度,非常适合硬件实现.     

城市快速路出口附加车道渠化长度仿真研究

以现场实测道路交通数据为基础，对VISSIM微观仿真模型进行标定及有效性检验，以出口速度及流量为评价指标研究不同交通流量组合下附加车道渠化长度的变化规律．研究表明，合理的渠化长度可改善出口交通状况，提高辅路及出口通行能力，建议出口附加车道渠化长度取值20m．     

基于微观仿真技术的交叉口渠化研究

从路口交通流的微观特性入手,在分析交叉口延误模型的基础上,采用路口微观交通仿真软件Synchro对深圳市某重要交叉口进行了实际的仿真分析,并提出了合理的渠化方案,从而为改善节点交通提供了有力的技术支持和理论依据。     

南水北调东线截污导流尾水综合处置方案研究

为满足国家对南水北调东线工程江苏段出省水质要求,徐州市和宿迁市的处理尾水通过尾水导流工程经新沂河入黄海,导流入新沂河尾水量41万t/d,COD污染负荷达14 965 t/a,使现状劣Ⅴ类水体的新沂河更加不堪重负,导致新沂河沿线至入海口附近近海水域的生态环境进一步恶化.2 550 m2人工湿地中试工程实验结果表明,湿地床技术能有效的净化污染河水,对COD的去除率可达60%～70%,氨氮的去除率达75%～85%;水葱(Scirpus locustris)、春兰(Gymbidium goeringii)等植物具有较强的耐淹特性.根据充分利用当地资源、以最小的建设投资和运行费用达到工程目标的原则,利用新沂河束水型行洪河道具有大量滩地资源特征,优化布置人工湿地床进行新沂河污染河水处置工程方案的设计.     

多相滤波数字信道化的FPGA实现

以多相滤波为基础,结合均匀滤波器组,采用50％重叠的子信道划分,提出了一种数字信道化实现方法,解决了高速实时处理与FPGA处理速度之间的矛盾,克服了信道化接收机的接收盲区.基于FPGA,提出了短波宽带数字信道化的设计思路和实现方法.仿真结果表明,该设计有较强的实用性和通用性.     

Phase estimation in data channelization for video transmitting

Channelization is one of the important techniques for sharing a single physical channel among the multiple videos. In channelization, the videos are partitioned into segments and the bandwidth of the physical channel is partitioned into logical channels. The first segment of each video is transmitted through the first logical channel, the second segment of each video is transmitted through the second logical channel, and so forth. The segments are transmitted periodically through the logical channels. In this paper, the video signals to be transmitted through the logical channels are estimated. Furthermore, the phase is estimated in terms of jitter delays that occur among the video segments, while transmitting them through the logical channels. The phase is an important parameter in video communication latency. Using the phase, the group delay can be estimated and based on the group delay, the storage space required at the client’s site can be determined so that the continuous and jerk-free delivery of the videos is provided to the users.     

Fish assemblage response to recent mitigation of a channelized warmwater stream

Various designs of low‐head dams are used to rehabilitate streams or forestall upstream channel incision after channelization. We report on the efficacy of using notched sills and grade control structures (GCS) to restore the fish assemblage in Luxapallila Creek, Mississippi. We tested the null hypotheses that habitat variables and species richness, evenness, and assemblage structure would not differ among: (1) a channelized segment with no modifications; (2) a channelized segment mitigated by the installation of sills and GCS; (3) a segment upstream of the installations and undergoing channel incision; and (4) an unaltered segment. Although habitat variables changed, neither species richness, evenness, nor fish assemblage structure differed between mitigated and channelized segments with both exhibiting less richness and different assemblage structures than the unaltered segment. Lack of differences in species richness between the incised and unaltered segments suggest that the GCS may have halted the negative effects of upstream channel incision before species were extirpated. Conspicuous habitat differences between the altered (channelized and mitigated) and unaltered segments were lack of backwaters and canopy coverage and finer substrates in the altered segments. Our results suggest a more comprehensive rehabilitation strategy is required in Luxapallila Creek. Published in 2003 by John Wiley & Sons, Ltd.