高速公路强制换道持续时间半参数生存分析

为了分析高速公路施工作业区车辆的换道行为,运用生存分析的半参数方法,建立基于风险的车辆强制换道持续时间模型,通过无人机采集包茂高速公路陕西境内某路段施工作业区的交通数据,对道路车辆强制换道持续时间进行估计.结果表明:强制换道持续过程的生存时间大于5s的概率约为80%,大于10s的概率为28%,一半以上处在5～10s之间;当距离小于400m时,换道起点至合流点距离越近,车辆强制换道持续时间越短;当距离大于400m时,车辆换道持续时间开始降低.车辆换道时间持续到t时刻,在至合流点距离50～100m范围内开始换道的车辆,在下一时刻完成换道的可能性最大.

Managing Water Quality in Huntsman Lake （Virginia, USA）reDevelopment and Implementation of Restoration Strategies

Huntsman Lake is located within the Middle Run of the Pohick Creek watershed, which is itself located within the much larger Chesapeake Bay watershed. Data collected from both the water column and the lake＇s sediments indicate that phosphorus-rich bottom sediments are an important internal loading source, and these internal phosphorus loads would continue to adversely impact water quality until and unless sediments are removed or inactivated. The implementation of artificial circulation was anticipated to be able to increase the sequestration of phosphorus within better oxygenated bottom sediments, and was the first lake management strategy deployed in Huntsman Lake. In the first two years after the installation of a whole-lake circulation system, the lake＇s waters are no longer stratified, and the bottom waters are no longer hypoxic and/or anoxic. While there is no evidence of a subsequent reduction in concentrations of nitrogen or chlorophyll-a, average phosphorus concentrations have decreased. However, high variability in the phosphorus data decreases our confidence that this is a sustained improvement. These results are consistent with prior findings, including those from downstream systems, that the reversal of the symptoms of eutrophication can involve lag-periods up to several years, if they are successful at all.

Quantification of Nutrient Assimilative Capacity of Chara （sp.） in a Previously Hypereutrophic Lake in Southwest Florida （USA）： Implications for Lake Management

The Sunshine Lake/Sunrise Waterway System, located in Southwest Florida （USA） previously experienced extensive and persistent algal blooms, with noxious odors and deep organic-rich sediments. This algal bloom was addressed via a lake-wide dredging project to remove the material from the lake bottom. A contributing factor to the algal bloom is elevated phosphorus in stormwater runoff, likely due to naturally phosphorus-rich geology in the surrounding watershed. Due to the naturally elevated phosphorus supply, excessive nutrient loads will likely continue in the future. An ongoing monitoring program, initiated after the dredging of the lake, determined that a type of algae （Chara sp,） other than that which caused the initial bloom had established itself by October 2015. This plant biomass is considered an alternative destination for incoming nutrient loads, and as such should be managed, rather than eliminated via the use of herbicides. The abundance and nutrient content of the mass of Chara sp. in the lake and waterway was estimated, and the amount of external nutrient load that would be removed from the lake with physical harvesting of Chara sp. was quantified. The cost-effectiveness of nutrient removal via physical harvesting of Chara sp. was then compared against typical stormwater treatment ponds.

Uncovering the influence of ChatGPT's prompts on traffic safety information using text mining approach

ChatGPT has emerged as a promising advanced large language model that needs prompt to gain information.However,designing a good prompt is not an easy task for many end-users.Therefore,this study intends to determine the amount of information gained because of varied amounts of information in the prompt.This study used two types of prompts,initial and improved,to query the introduction sections of 327 highly cited articles on traffic safety.The queried introduction sections were then matched with the corresponding human-written introduction sections from the same articles.Similarity tests and text network analysis were used to understand the level of similarities and the content of ChatGPT-generated and human-written introductions.The findings indicate the improved prompts,which have the addition of generic persona and information about the citations and references,changed the ChatGPT's output insignificantly.While the perfect similar contents are supposed to have a 1.0 similarity score,the initial and improved prompt's introduction materials have average similarity scores of 0.5387 and 0.5567,respectively.Further,the content analysis revealed that themes such as statistics,trends,safety measures,and safety technologies are more likely to have high similarity scores,irrespective of the amount of information provided in the prompt.On the other hand,themes such as human behavior,policy and regulations,public perception,and emerging technologies require a detailed level of information in their prompt to produce materials that are close to human-written materials.The prompt engineers can use the findings to evaluate their outputs and improve their prompting skills.