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Acute Bilateral Optic Neuropathy: A Rare Presentation of Wernicke Encephalopathy. 急性双侧视神经病变:罕见的韦尼克脑病表现。
IF 2.9 4区 工程技术 Q3 ENGINEERING, CIVIL Pub Date : 2023-12-01 Epub Date: 2022-03-23 DOI: 10.1097/WNO.0000000000001527
Kristine M Nachbor, Olufemi E Adams, Chase A Liaboe, Anne S Abel
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引用次数: 0
Simulation Study of Pedestrians Evacuation Considering Aggressive Behavior 考虑攻击行为的行人疏散仿真研究
4区 工程技术 Q3 ENGINEERING, CIVIL Pub Date : 2023-11-13 DOI: 10.1177/03611981231207843
Qinghua Mao, Yang Li, Rongfu Yu
Conflict during an evacuation may turn into aggressive behavior and create problems for evacuation. To study the influence of attack behaviors such as pushing and shoving on evacuation and the evacuation law, an extended cellular automata model is developed in this paper. In the model, pedestrian movement is influenced by static, dynamic, and attack floor fields. In addition, pedestrian vision is influenced by the direction and location of movement of surrounding pedestrians, and pedestrians adopt different coping strategies for attacks: avoidance detour, or imitation. Attacker movement and aggressive behavior are also studied. Numerical simulations are conducted to discuss the pedestrian evacuation problem under attack behavior. The effects of the evacuation process, attack field sensitivity coefficient, location of fallen pedestrians, pedestrian density, number of initial attackers, initial attacker location, and pedestrian imitation ratio on evacuation time and number of fallen pedestrians are analyzed. The simulation results show that an appropriate increase in the impact of the attack field can slow down the congestion, that is, the evacuation time is the fastest at k A = 0.5. The evacuation time is faster when the room is full of normal pedestrians or full of attacking pedestrians. The number of casualty pairs is high when the initial position of the attacker is in the middle of the inner side of the room. The results of the study can provide recommendations and guidance for the formulation of evacuation strategies for pushing and shoving type attacks and reducing casualties.
疏散过程中的冲突可能会转变为攻击行为,给疏散带来麻烦。为了研究推、推等攻击行为对疏散的影响及疏散规律,本文建立了扩展元胞自动机模型。在模型中,行人的运动受到静态、动态和攻击地板场的影响。此外,行人的视觉受到周围行人运动方向和位置的影响,行人对攻击采取不同的应对策略:回避绕行或模仿。攻击者的运动和攻击行为也进行了研究。对攻击行为下的行人疏散问题进行了数值模拟。分析了疏散过程、攻击场敏感系数、倒下行人位置、行人密度、初始攻击者数量、初始攻击者位置、行人模仿比等因素对疏散时间和倒下行人数量的影响。仿真结果表明,适当增加攻击场的影响可以减缓拥塞,即在k A = 0.5时疏散时间最快。当房间里满是正常行人或满是攻击行人时,疏散时间更快。当攻击者的初始位置在房间内侧的中间时,伤亡人数会很高。研究结果可为推搡型袭击的疏散策略制定提供建议和指导,减少人员伤亡。
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引用次数: 0
Analyzing Freeway Safety Influencing Factors Using the CatBoost Model and Interpretable Machine-Learning Framework, SHAP 基于CatBoost模型和可解释机器学习框架的高速公路安全影响因素分析
4区 工程技术 Q3 ENGINEERING, CIVIL Pub Date : 2023-11-13 DOI: 10.1177/03611981231208903
Jiaqi Li, Xuesong Wang, Xiaohan Yang, Qi Zhang, Hanzhong Pan
Exploring and analyzing safety influencing factors can guide targeted traffic safety management. Traditional traffic safety models are aimed at specific data problems and making adjustments to the model structure, which lack focus on predictive ability and have limited information on the analysis of influencing factors. In recent years, machine-learning methods have opened new avenues in modeling that have higher prediction accuracy, can identify complex nonlinear relationships, and can overcome over- and under-dispersion and correlation. Machine-learning methods, however, pose the problem of limited interpretability. The interpretable machine-learning framework SHAP can be an effective solution, which can not only reflect the influence of features in each sample but also generate global interpretation. This study established gradient boosting models including the CatBoost and XGBoost models as traffic safety models, which were compared with a traditional NB regression model and a zero-inflated negative binomial regression model. SHAP was used to analyze several safety influencing factors, including geometric design features, traffic operation characteristics, time of day, and land use. Results confirmed that the CatBoost model has better prediction ability and is a more suitable traffic safety model than the traditional negative binomial regression model. Among the key findings were that ramp type is the most important factor in freeway crash frequency; curve presence has a great positive impact, while truck proportion has a great negative impact; and traffic volume is highly correlated with truck proportion. These findings can provide theoretical support for safety operation management and targeted improvement measures for freeways.
探索和分析安全影响因素,可以指导有针对性的交通安全管理。传统的交通安全模型针对具体的数据问题,对模型结构进行调整,缺乏对预测能力的关注,对影响因素分析的信息有限。近年来,机器学习方法在建模方面开辟了新的途径,具有更高的预测精度,可以识别复杂的非线性关系,并且可以克服过度和欠分散和相关性。然而,机器学习方法存在可解释性有限的问题。可解释的机器学习框架SHAP是一种有效的解决方案,它不仅可以反映每个样本中特征的影响,而且可以产生全局解释。本文建立了包括CatBoost和XGBoost模型在内的梯度助推模型作为交通安全模型,并与传统NB回归模型和零膨胀负二项回归模型进行了比较。利用SHAP分析几何设计特征、交通运行特征、时间和土地利用等安全影响因素。结果表明,与传统的负二项回归模型相比,CatBoost模型具有更好的预测能力,是一种更合适的交通安全模型。主要发现包括:匝道类型是影响高速公路碰撞频率的最重要因素;曲线存在有较大的正向影响,卡车比例有较大的负向影响;交通量与卡车比例高度相关。研究结果可为高速公路安全运行管理和有针对性的改进措施提供理论支持。
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引用次数: 0
Numerical Analysis of Error From Sampling of Alternatives in Logit-Based Demand Forecasting Models with Massive Choice Sets 基于logistic的海量选择集需求预测模型中备选方案抽样误差的数值分析
4区 工程技术 Q3 ENGINEERING, CIVIL Pub Date : 2023-11-10 DOI: 10.1177/03611981231190634
Max Gardner, Paul Waddell
Use of the multinomial logit (MNL) functional form is widespread in transportation and land use demand modeling. As the state-of-the-art evolves away from aggregate forecasting and toward activity-based models and microsimulation, MNL models are being asked to accommodate increasingly large choice sets. Different strategies exist to address the challenge of estimating models with very large choice sets, but perhaps none is as commonly employed as sampling of alternatives. The effect of sampling of alternatives on parameter estimation has received considerable attention in the scientific literature. Yet comparatively little quantitative research exists that examines the issues that arise when the same sampling strategies are applied in the context of forecasting. In this study we conducted an analysis of the effect of sampling of alternatives in discrete choice models for disaggregate location choice forecasting. First, a novel measure of forecast error was defined and then used to quantify the extent of the problem as a function of sample rate, model error, and size of the universe of alternatives. Finally, we explored the potential for strategic sampling techniques to reduce the error observed under simple random sampling. In general, we found that the proportion of aggregate demand that was misallocated owing to sampling of alternatives was actually reduced as the size of the universe of alternatives increased. Additionally, simple random sampling was shown to outperform importance sampling in most scenarios. These findings suggest that error resulting from random sampling of alternatives is less of a problem for logit-based microsimulation models than previously assumed.
多项logit (MNL)函数形式在交通和土地利用需求建模中得到了广泛的应用。随着最先进的技术从总体预测向基于活动的模型和微观模拟发展,MNL模型被要求适应越来越大的选择集。存在不同的策略来解决具有非常大的选择集的估计模型的挑战,但也许没有一个像选择抽样那样常用。在科学文献中,选择抽样对参数估计的影响受到了相当大的关注。然而,相对而言,很少有定量研究审查在预测中应用相同的抽样策略时所产生的问题。在本研究中,我们对离散选择模型中选择抽样的影响进行了分析。首先,定义了一种新的预测误差度量,然后将问题的程度量化为样本率、模型误差和备选方案范围的函数。最后,我们探索了策略抽样技术的潜力,以减少在简单随机抽样下观察到的误差。总的来说,我们发现,由于选择抽样而导致的总需求错配比例实际上随着选择范围的增大而减小。此外,在大多数情况下,简单随机抽样被证明优于重要性抽样。这些发现表明,随机抽样产生的误差对基于逻辑的微观模拟模型的影响比以前假设的要小。
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引用次数: 0
Equity of Highway Noise Exposure 公路噪声暴露公平性
4区 工程技术 Q3 ENGINEERING, CIVIL Pub Date : 2023-11-09 DOI: 10.1177/03611981231205886
Thor Dodson, Viktoriia Dunleavy
This article discusses the inequities in exposure to highway noise, which can have adverse effects on health, productivity, and quality of life. If certain subpopulations tend to live near highways because of structural inequality, gentrification, lack of social capital, or other reasons, then highway noise can contribute to inequity in a systematic way. The authors developed an online mapping application, the Noise Inequity Identification Tool (NIIT), to visualize the noise damage cost of noise pollution from road segments, the noise-equity ratios at the county level, and the population distribution of various demographics. The methodology combines estimates of roadway traffic noise levels with the cost of noise damage from the hedonic pricing literature and estimates of the number of households affected to estimate the noise damage cost for each road segment in the U.S. The cost of the noise damage accruing to each demographic is then aggregated over a larger region and normalized by their proportion of the population to calculate the “noise-equity ratio,” revealing substantial inequities in highway noise exposure between demographics at a variety of spatial scales. By using this tool, planners and practitioners can easily identify regions with existing highway noise exposure inequities and pinpoint roadways with excessive noise damage costs to recommend potential externality mitigation projects.
这篇文章讨论了暴露在高速公路噪音中的不平等,这可能对健康、生产力和生活质量产生不利影响。如果由于结构不平等、中产阶级化、缺乏社会资本或其他原因,某些亚群体倾向于住在高速公路附近,那么高速公路的噪音就会以一种系统的方式加剧不平等。作者开发了一个在线地图应用程序,即噪声不公平识别工具(NIIT),以可视化道路噪声污染的噪声损害成本,县级噪声公平比率以及各种人口统计数据的人口分布。该方法结合了来自享乐定价文献的道路交通噪音水平和噪音损害成本的估计,以及受影响的家庭数量的估计,以估计美国每个道路段的噪音损害成本。然后,每个人口的噪音损害成本在更大的区域内汇总,并按其人口比例归一化,以计算“噪音权益比”。揭示了高速公路噪声暴露在不同空间尺度人口统计之间的巨大不平等。通过使用这一工具,规划者和从业者可以很容易地识别现有公路噪音暴露不平等的地区,并查明噪音损害成本过高的道路,以推荐潜在的外部性缓解项目。
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引用次数: 0
Energy-Efficient Train Operation Optimization in Istanbul Metro Network Considering Variable Passenger Numbers 考虑客流量变化的伊斯坦布尔地铁网络节能运行优化
4区 工程技术 Q3 ENGINEERING, CIVIL Pub Date : 2023-11-09 DOI: 10.1177/03611981231205876
Ahmet Yildiz, Oktay Arikan, Kemal Keskin
This manuscript presents a speed trajectory optimization to minimize driving energy consumption using four different nature-inspired algorithms. For this purpose, a model was developed that can simulate motion of a single train. To test the train motion model and speed trajectories, Istanbul M3 subway line was modeled with its actual parameters such as gradient, curve, and speed limit. Concerning computational time and energy usage, a straightforward speed profile and proposed speed profiles by the algorithms have been compared. Afterwards, variable passenger numbers at each station in a certain hour were taken as dynamic mass input. With the marine predator algorithm (MPA) that finds the best result among the four, speed profile optimization was performed again under the effect of unstable mass. Finally, a train was operated by a driver according to the optimal speed profile. As a result, energy saving is 18.75% in simulation environment and 21.27% in real-life test.
该手稿提出了一个速度轨迹优化,以尽量减少驾驶能源消耗使用四种不同的自然启发算法。为此,开发了一个可以模拟单列火车运动的模型。为了验证列车的运动模型和速度轨迹,伊斯坦布尔M3地铁线路采用其坡度、曲线、限速等实际参数进行建模。在计算时间和能量消耗方面,比较了简单的速度剖面和算法提出的速度剖面。然后,将某一小时内各车站的可变客流量作为动态质量输入。采用四种算法中最优的海洋捕食者算法(MPA),在质量不稳定的影响下再次进行航速剖面优化。最后,由驾驶员按照最优速度剖面操作列车。仿真环境节能18.75%,实际测试节能21.27%。
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引用次数: 0
Optimization of the Grout Mix Ratio and Simulation Test of Shield Tail Grouting Similarities in a Water-Rich Fine Sand Layer 富水细砂层盾构尾浆配合比优化及相似度模拟试验
4区 工程技术 Q3 ENGINEERING, CIVIL Pub Date : 2023-11-09 DOI: 10.1177/03611981231198480
Yang Song, Ang Li, Hongshuai Wang, Xiaofeng Xu, Xin Wang, Zuoming Xiao, Qiang Yuan
When shield tunneling is performed in water-rich silt and fine sand strata, the grout becomes runny when diluted by groundwater. After dilution, the filling effect of the grout is not significant, and the level of surface settlement is very high. In this study, based on bidding section 04 of Tianjin Metro Line 11, traditional grouting materials were selected to conduct response surface method (RSM) tests. The purposes of the RSM analysis were to analyze the interactions between materials and their influences on grout performance and to optimize the grout mix ratio. Various admixtures were compared to assess the effects of different admixtures and compositions on the dispersion resistance and flow performance of the grout. Finally, a shield synchronous grouting test system was developed, and a similar indoor grouting simulation test was performed to analyze the influences of the different admixtures on the filling effects and to determine a reasonable grout mix ratio. The following three results were obtained. (1) The RSM was suitable for grout performance prediction and grout mix ratio optimization, and hydroxyethyl cellulose could improve the grout performance and increase the bond performance between the cementing material and aggregate. (2) Admixture incorporation enhancement could improve the grout utilization rate and increase the diffusion distance at the top of the tunnel, which would be conducive to filling the gap at the tail end of the shield. (3) The optimal preparation scheme of grout in water-rich fine sand formations included a water–binder ratio of 0.72, cement–sand ratio of 0.80, fly ash content of 5%, bentonite content of 14.94%, and admixture content of 0.8%–0.9%
在富水粉砂细砂地层中进行盾构隧道施工时,浆液被地下水稀释后呈流状。稀释后的灌浆充填效果不显著,地表沉降水平很高。本研究以天津地铁11号线04标段为基础,选择传统注浆材料进行响应面法(RSM)试验。RSM分析的目的是分析材料之间的相互作用及其对浆液性能的影响,并优化浆液配合比。比较了不同掺合料对浆液分散阻力和流动性能的影响。最后,研制了盾构同步注浆试验系统,并进行了类似的室内注浆模拟试验,分析了不同外加剂对充填效果的影响,确定了合理的注浆配合比。得到了以下三个结果。(1) RSM适用于浆液性能预测和浆液配合比优化,羟乙基纤维素可以改善浆液性能,提高胶结材料与骨料的粘结性能。(2)增强外加剂掺入可提高浆液利用率,增加隧道顶部扩散距离,有利于盾构尾端空隙的填充。(3)富水细砂地层浆液的最佳配制方案为水胶比0.72,水砂比0.80,粉煤灰掺量5%,膨润土掺量14.94%,外加剂掺量0.8% ~ 0.9%
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引用次数: 0
Two-Layer Porous Asphalt: Main Properties to Decrease the Noise Emissions 双层多孔沥青:降低噪音的主要性能
4区 工程技术 Q3 ENGINEERING, CIVIL Pub Date : 2023-11-09 DOI: 10.1177/03611981231203231
Daniel Castro-Fresno, Helena Miera-Dominguez, Pedro Lastra-González, Irune Indacoechea-Vega, Ronald van Loon, Gijsjan van Blokland
Road transportation is one of the major sources of noise emissions that seriously affect human health. The porous surfaces of roads are sound absorbing, which helps to reduce noise pollution. For this purpose, different two-layer porous asphalt mixtures were evaluated both mechanically and functionally, to develop an asphalt mixture that reduces the noise generated between tires and road. This research focused on the variables that determine the main properties to be considered: texture wavelength spectrum, acoustic absorption, and flow resistivity. Void content, thickness, and maximum aggregate size were identified as the variables that should be controlled to decrease noise emissions.
道路交通是严重影响人体健康的主要噪声源之一。多孔路面具有吸声作用,有助于减少噪音污染。为此,对不同的两层多孔沥青混合料进行了机械和功能评估,以开发一种减少轮胎和道路之间产生的噪音的沥青混合料。本研究的重点是决定要考虑的主要性质的变量:纹理、波长光谱、声吸收和流动电阻率。孔隙含量、厚度和最大骨料粒径被确定为应控制的变量,以减少噪声排放。
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引用次数: 0
Bus Operation Safety Business Intelligence Solution: Applying Analytics for Key Performance Indicator, Investigation, and Targeted Actions Analyses with a Centralized Data Warehouse 总线运行安全商业智能解决方案:使用集中数据仓库对关键性能指标、调查和目标行动分析进行分析
4区 工程技术 Q3 ENGINEERING, CIVIL Pub Date : 2023-11-09 DOI: 10.1177/03611981231205882
Xiaotong Ding, John Maleyeff, Frans Valk
A business intelligence (BI) system was designed to create a proactive, reactive, and precursor decision tool to improve safety of bus operations at the Massachusetts Bay Transportation Authority (MBTA). The system’s development was motivated in part by recommendations of a safety inspection by the Federal Transportation Administration, and the realization that the MBTA has access to vest amounts of data that are not being used to create information effectively. The developers reduced the complexity of the BI system by incorporating analytics to determine the areas of focus where safety has the most impact. Challenges were posed by the need to integrate internal and external databases with various formats and structures, and the desire to create a self-service BI solution for multiple MBTA users. The resulting BI solution includes applications that support key performance indicator analyses, root cause investigations, and targeted improvement actions. These applications represent an enhanced approach that combines data for a more holistic analysis and eliminates the need to transfer datasets or data analyses by email. The system includes various forms of visualizations to help users navigate the myriad of information, including geospatial maps, interactive pie, line, and bar charts, and word frequency and relationship mapping. The paper details the system’s development and how analytical approaches were used to expose important information that is hidden in the data. Examples of applications are shown using screenshots and a general workflow is presented that could be applicable to agencies with fewer resources.
设计了一个商业智能(BI)系统,用于创建一个主动、被动和先行的决策工具,以提高马萨诸塞湾交通管理局(MBTA)公交运营的安全性。开发该系统的部分动机是联邦运输管理局(Federal Transportation Administration)的安全检查建议,以及MBTA可以访问大量数据,而这些数据没有被有效地用于创建信息。开发人员通过结合分析来确定安全影响最大的重点领域,从而降低了BI系统的复杂性。挑战来自于需要集成具有各种格式和结构的内部和外部数据库,以及为多个MBTA用户创建自助BI解决方案的愿望。最终的BI解决方案包括支持关键性能指标分析、根本原因调查和目标改进行动的应用程序。这些应用程序代表了一种增强的方法,将数据结合起来进行更全面的分析,并消除了通过电子邮件传输数据集或数据分析的需要。该系统包括各种形式的可视化,以帮助用户浏览大量的信息,包括地理空间地图、交互式饼状图、线形图和条形图,以及词频和关系映射。本文详细介绍了该系统的开发以及如何使用分析方法来揭示隐藏在数据中的重要信息。应用程序示例使用屏幕截图显示,并提供了适用于资源较少的机构的一般工作流程。
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引用次数: 0
Data-Driven Analysis of Rural Equity and Cost Concerns for Mileage-Based User Fees in Vermont 数据驱动的佛蒙特州基于里程的用户收费的农村公平和成本问题分析
4区 工程技术 Q3 ENGINEERING, CIVIL Pub Date : 2023-11-09 DOI: 10.1177/03611981231206167
Clare Nelson, Gregory Rowangould
Examining substitutes to the current state and federal gasoline and diesel fuel excise taxes has become a pressing issue, exacerbated by the rise of high-efficiency and alternative-fuel vehicles threatening the revenue-generating capacity of these taxes. A mileage-based user fee has been frequently proposed in the literature as an alternative that would offer greater benefits to rural and low-income populations than to urban and higher-income populations. However, most prior analyses relied on small data sets and aggregated data. This study examined the impact of replacing the Vermont state fuels tax with a revenue-neutral, mileage-based user fee using mileage and fuel economy data for over 300,000 registered passenger vehicles. We found that, on average, Vermont households would pay an additional $23 per year, with rural households and low-income households facing smaller tax burdens than their urban and high-income counterparts. The impact of a $180 flat fee replacing the Vermont state motor fuels tax was also examined owing to state interest. Findings indicated that a flat fee would result in much larger price fluctuations, with most households paying an additional $47 per year. The disaggregated data approach presented here directly addresses public misconceptions of inequitable cost differences and provides context for public education campaigns to garner mileage-based user fee policy support. Based on our results, there is political ground for further research into the implementation of a mileage-based user fee, including the logistics of an administrative transition to mileage charging and the associated program implementation and technological costs.
研究现有州和联邦汽油和柴油消费税的替代品已成为一个紧迫的问题,而高效率和替代燃料汽车的兴起威胁着这些税收的产生能力,这一问题更加严重。文献中经常提出按里程收费作为一种替代办法,这种办法将比城市和高收入人口给农村和低收入人口带来更大的好处。然而,大多数先前的分析依赖于小数据集和汇总数据。本研究利用30多万辆注册乘用车的里程和燃油经济性数据,考察了用收入中性、基于里程的用户收费取代佛蒙特州燃油税的影响。我们发现,平均而言,佛蒙特州家庭每年要多支付23美元,农村家庭和低收入家庭面临的税收负担比城市和高收入家庭要小。由于国家利益,还审查了180美元统一费取代佛蒙特州汽车燃油税的影响。调查结果表明,统一收费将导致更大的价格波动,大多数家庭每年要额外支付47美元。本文提出的分类数据方法直接解决了公众对不公平成本差异的误解,并为公共教育活动提供了背景,以获得基于里程的用户收费政策支持。根据我们的研究结果,有进一步研究基于里程的用户收费的实施的政治基础,包括行政过渡到里程收费的后勤以及相关的计划实施和技术成本。
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引用次数: 0
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Transportation Research Record
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