系泊索属性对开敞式码头船舶系泊安全的影响分析

结合某工程实例,运用OPTIMOOR系泊分析软件,研究系泊索属性对开敞式码头船舶系泊安全的影响。以减少环境荷载作用下船舶运动量、均衡缆绳张力和减少断缆危险为目标,通过调节缆绳材质、直径,考虑导缆孔到绞盘的距离,增加预张力及缆尾索等方法,以期达到提高开敞式码头船舶系泊安全性的效果,此成果可为码头设计及港口管理人员提供参考。     

地铁区间隧道环境温度影响因素分析和预测模型研究

利用地铁区间隧道环境温度的实测数据,分析了大气温度、大气相对湿度、列车数量、客流量、运行年限对地铁区间隧道环境温度的影响,并利用回归分析得到了区间隧道环境温度的预测模型.分析结果显示:外界大气温度直接影响区间环境温度的变化趋势;区间隧道环境温度与外界大气相对湿度、列车数量和客流量具有相似的波动规律;运行年限的增加导致区间隧道热堆积加剧,使区间隧道环境温度逐年升高;利用回归模型的T检验结果可以得到各因素对区间隧道环境温度的影响程度,而回归模型可以较准确地预测隧道环境温度.     

轨道交通行车调度调整方法探讨

分析轨道交通行车故障的特征,阐述列车调整方法的种类、使用条件和使用要求;结合苏州轨道交通1号线的线路特点,模拟故障处理,达到综合应用调整方法的效果     

人行天桥人桥共振解决方案

介绍了人行天桥人桥共振问题的解决方案,通过多个方案的计算、分析、比较,从设计角度提供了比较合理可行的方案,为解决现有同类型天桥共振问题提供参考.     

Simple closed-loop method to compensate interference asymmetry in time-division duplex MIMO-OFDM systems

In wireless communications systems with time-division duplex (TDD) deployment, channel reciprocity and symmetric interference between transmitter and receiver sides are two widely-adopted assumptions for the design of optimal adaptation transmission mode. However, in practice, there is an undesirable but non-negligible effect, namely the asymmetric interference, that makes the assumptions no longer valid. In this paper, a simple closed-loop feedback method of compensating interference asymmetry in TDD multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) system is proposed. The system makes the estimated interference at transmit-side be able to track the instantaneous receive-side interference dynamically. The proposed method maintains constant frame error rate (FER) by adopting adaptive modulation coding (AMC) and power loading. The final simulations have verified the effectiveness of the new method.     

A semi-fragile wavelet transform watermarking scheme for content authentication of images

A novel semi-fragile watermarking scheme for the content authentication of images using wavelet transform (WT) is presented in this paper. It is tolerant to the embedded wavelet image compression methods based on WT such as embedded zerotree wavelet (EZW), set partitioning in hierarchical trees (SPIHT) and embedded block coding with optimized truncation (EBCOT) in JPEG2000 to a pre-determined bit-plane, but is sensitive to all other malicious attacks. The image features are generated from the lowest-frequency (LF) subband of the original image as the embedded watermark. The watermark is embedded into the pre-determined bit-plane by adjusting the corresponding values in the given subband. In the process of watermarking authentication, we compare the image features generated from the LF subband of the received image with the embedded watermarking information (the image features of the original image) extracted from the pre-determined bit-plane in the given subband of the received image to decide whether the image is attacked maliciously or processed acceptably (the embedded wavelet compression). The most important advantage of our watermarking scheme is that the watermark information can be extracted from the watermarked image when detecting watermark, so the received image authentication needs no information about the original image or watermark. Experimental results prove the effectiveness of our proposed watermarking scheme.     

汽车空调过滤器性能试验研究

利用电镜分析了汽车空调过滤器滤料纤维结构及其对过滤效率、空气阻力的影响,分析了滤料纤维结构存在的问题和改进措施.通过试验数据分析确定了过滤速度、微粒直径变化对过滤器过滤效率的影响以及过滤速度变化对过滤器阻力的影响.针对过滤器阻力大及对小粒径颗粒过滤效率低等问题提出了解决办法.     

集通铁路营业线施工安全管理

分析集通铁路（集团）公司营业线施工安全问题,探讨安全管理、施工计划、重点环节等对营业线施工安全的影响,针对人员培训、计划提报审核、现场作业组织、关键环节卡控、安全技术交底等方面,提出科学有效地管理施工,提高营业线施工的做法和经验。     

数字移动通信接入信令分析

阐述了数字移动通信的关键技术——接入信令。对接入信令的格式、传输协议和传输方式等进行了具体分析。     

舱室充气加压时间的计算

船上有些舱室需要充气加压,客户需要了解充气加压的时间以及保压时间等参数。本文分析了舱室充气加压过程中室内气体状态变化情况,给出了充气时间的计算公式,并给出了保压过程中室内气压因温度下降而引起的压降值的估算方法。