.NET环境下实现DES及MD5加密

加密技术通常用于保护机密信息的安全性和完整性。由于加密技术比较复杂,如果用户自行编程实现加密算法不但费时费力而且难以保证安全性和可靠性。微软发布的.NET框架中提供了一套完整的加密算法实现方法类,用户可以根据自己的需求直接调用,实现起来快速、安全、可靠。     

京昆高速G5(河池寨至三星立交段)与西安高新区路网连接及交通节点研究

京昆高速G5(河池寨至三星立交段)对西安高新区和昆明池的分隔效应严重阻碍了区域一体化发展。利用京昆高速G5改扩建契机,通过分析现状和解读规划,发现存在的问题,提出京昆高速G5(河池寨至三星立交段)与西安高新区路网连接及交通节点研究的总体策略为多路径迂回,多点集散。具体提出了两大方案,并从方案特点、解决功能、工程造价等方面比选出推荐方案。项目研究体现了“策划引领、规划先行”的前期策划理念。     

参数选取对探地雷达厚度检测的影响

对探地雷达应用条件进行了探讨,对近年来探地雷达技术发展及新的应用研究进行了概括和总结,详细分析探地雷达的工作原理、系统组成结构,进而指出探地雷达的局限性和今后的发展方向。     

SS5型客运电力机车(6)——TBQ5—5225/25主变压器(含平波电抗器、滤波电抗器)

本文介绍了SS5型电力机车主变压器(含平波电抗器、滤波电抗器)的主要技术数据、设计特点、主要结构以及与8K机车主变压器的对比等,并给出了阻抗电压实测值。     

基于.NET的软件虚拟实训环境设计

针对高校计算机专业学生软件开发经验的欠缺,运用相关技术,设计实现基于.NET和SQLServer的软件开发虚拟实训环境,学生能够在其中感受到规范的软件开发流程,迅速掌握高效的软件项目开发步骤与方法.     

Road traffic conditions in Kenya: Exploring the policies and traffic cultures from unstructured user-generated data using NLP

Road traffic accidents (RTA) are a prevalent cause of fatality with African countries having the highest fatality index (25–34 per quota). The World Health Organization estimates Kenya's fatality rate due to RTA at 28 per quota. From literature, the country's fatality and injuries have increased by 26% and 46.5%, respectively, since the year 2015. The country is faced with incomplete RTA data capturing, hindering effective planning and policy adjustments to curb the menace. In this paper, we scrapped user-generated data (Twitter) and national transport and safety authority's (NTSA) reports to shed light on traffic safety, practices, and cultures in the country. To this end, we gathered 1,000,000 tweets and 8000 speeding entries between 2015 and 2021 and performed natural language processing (NLP) and quantitative study of the data. We applied NLP and n-gram search of keywords to categorize data into 8 topics: traffic, public service vehicle (PSVs), policing, accident, infrastructure, recklessness, robbery, and corruption. From the data, policing, which touches on all police and law-enforcement-related activity was found to be highly correlated with PSVs, recklessness, accidents, traffic congestion, robbery, infrastructure, and corruption with indices of r(76) = 0.92, 0. 91, 0.87, 0.82, 0.81, 0.76, and 0.70, respectively with p < 0.001. The topic modeling confirmed the identified topics to be the latent discussion issues affecting the public. From the study, PSVs, policing and traffic flow were isolated as key issues that ought to be addressed immediately. The research recommended the integration of driver monitoring systems to strengthen policing. The research, which utilized unstructured data, points to the utility of data mining which would greatly benefit traffic research, particularly African-based studies, that suffer from data inadequacy.     

地方铁路移动通信制式探讨

近年来,在国家政策的大力支持下,地方铁路蓬勃发展,由地方人民政府主导设计、施工建设,国家铁路主管部门提供必要的技术支持和施建审批。移动通信制式选择时,需依据铁路经营管理模式、机车交路、业务需求等不同特点,结合技术制式的频率资源可实施性、先进性、成熟度、运营维护是否方便、工程经济性等因素,合理选择方案。本文介绍了地方铁路目前主流的经营管理模式;研究了影响移动通信制式选择的因素;阐述了GSM-R、DMR、LTE、5G四种可选移动通信制式特性;并重点对四种可选制式从不同维度进行详细比选。     

What are the implications of climate change for trans-Atlantic aircraft routing and flight time?

The effect of wind changes on aircraft routing has been identified as a potential impact of climate change on aviation. This is of particular interest for trans-Atlantic flights, where the pattern of upper-level winds over the north Atlantic, in particular the location and strength of the jet stream, strongly influences both the optimal flight route and the resulting flight time. Eastbound trans-Atlantic flights can often be routed to take advantage of the strong tailwinds in the jet stream, shortening the flight time and reducing fuel consumption. Here we investigate the impact of climate change on upper-level winds over the north Atlantic, using five climate model simulations from the Fifth Coupled Model Intercomparison Project, considering a high greenhouse-gas emissions scenario. The impact on aircraft routing and flight time are quantified using flight routing software. The climate models agree that the jet stream will be on average located 1° further north, with a small increase in mean strength, by 2100. However daily variations in both its location and speed are significantly larger than the magnitude of any changes due to climate change. The net effect of climate change on trans-Atlantic aircraft routes is small; in the annual-mean eastbound routes are 1 min shorter and located further north and westbound routes are 1 min longer and more spread out around the great circle. There are, however, seasonal variations; route time changes are larger in winter, while in summer both eastbound and westbound route times increase.     

中国至尼泊尔跨境铁路最大坡度研究

中国至尼泊尔跨境铁路穿越喜马拉雅山脉,具有显著的地形高差,海拔从佩枯错4 600 m急骤下降至加德满都1 360 m,部分地段自然纵坡达50‰及以上,需要采用较大坡度以适应地形。在分析国内外大坡度铁路使用及发展的基础上,结合项目地形特点对坡度方案进行分段研究,重点对佩枯错至加德满都段最大坡度方案从运输安全性、运输质量、运输能力和运输经济性等方面综合分析论证。结合长大下坡紧急制动距离的要求,分析客货列车下坡限速,考虑牵引力、制动力、黏着力和车钩强度等限制条件,检算满足长大坡道客货列车牵引、制动安全的牵引质量和编挂辆数,并结合运输需求分析不同坡度方案能力适应性,通过模拟牵引计算比较列车运行速度,计算工程投资、机车购置费和运营费的费用现值,进行经济性比较。综合分析,本项目最大坡度日喀则至佩枯错段暂推荐采用13‰,佩枯错至加德满都段采用30‰。     

车辆段5T、AEI探测站维修作业通道开设方式探讨

本文针对铁路全封闭后,车辆段5T、AEI探测站维修人员进出困难的问题,提出了设置探测站作业通道需遵守的三条原则。归纳了栅栏直开、探测站双开门、围墙开门三种探测站作业通道的开设方式,比较各自优缺点和适用条件。建议在既有探测站增设作业通道时,需因地制宜,选择合理方案。在新建探测站工程时应同步进行作业通道的设计和施工。