Treed Avalanche Forecasting: Mitigating Avalanche Danger Utilizing Bayesian Additive Regression Trees

Little Cottonwood Canyon Highway is a dead‐end, two‐lane road leading to Utah's Alta and Snowbird ski resorts. It is the only road access to these resorts and is heavily traveled during the ski season. Professional avalanche forecasters monitor this road throughout the ski season in order to make road closure decisions in the face of avalanche danger. Forecasters at the Utah Department of Transportation (UDOT) avalanche guard station at Alta have maintained an extensive daily winter database on explanatory variables relating to avalanche prediction. Whether or not an avalanche crosses the road is modeled in this paper via Bayesian additive tree methods. Utilizing daily winter data from 1995 to 2011, results show that using Bayesian tree analysis outperforms traditional statistical methods in terms of realized misclassification costs that take into consideration asymmetric losses arising from two types of error. Closing the road when an avalanche does not occur is an error harmful to resort owners, and not closing the road when one does may result in injury or death. Copyright © 2016 John Wiley & Sons, Ltd.     

道路景观生态学研究进展

道路景观生态学目前在国内还是一个较新的概念,作者认为该领域主要包括三方面内容道路生态学影响、道路景观美学评价、道路景观规划与设计。本文从这三个方面分别综述了道路景观生态学国内外研究进展情况,并提出研究的重点领域道路的理化环境污染,道路修建对动植物栖息地的影响,道路景观空间格局与过程之间的相互作用机理,区域尺度道路网络的景观破碎化效应,道路生态学的网络理论,道路系统与周围环境的相互作用机制;道路选线对具有特殊美学价值(如自然河流、原始地貌、地方文化特色)区域的影响研究,道路使用者与沿线居民美学感知研究,公众参与途径机制的研究;3S技术在道路前期选线应用研究,道路构造物的美学处理等。最后本文对我国在该领域研究做了展望,认为未来应着重从两个方面进行突破总结国内外现有成果,引入新方法与理论,开展前沿领域研究;以典型旅游公路为突破口,开展细致深入的景观调查、路线优选、构造物美学设计等工作,以期公路设计部门形成重视前期道路景观选线与后期景观设计的思想。     

道路交通事故等间隔序列的灰色预测方法

在分析道路交通系统灰色属性的基础上，论文提出可以将道路交通事故作为道路交通系统行为特征量处理，运用灰色理论和方法来进行道路交通事故预测，在此基础上，建立了道路交通事故的等间隔序列灰色预测模型，并运用实例验证了模型的实用性。     

分解式PID-模糊控制及其在ABS中的应用

为解决路面发生跃变时车轮抱死的问题，提出一种分解式PID模糊控制器（p-I-D Fuzzy），并应用于ABS。建立模糊系统输出与输入的函数关系，结合PID表达式，理论分析表明该型控制器具有类似参数自适应整定PID的功能。分别在典型的高、中、低附着路面，以及跃变路面上进行仿真实验。结果表明这种控制器适应性强，在跃变路面下，超调量小，跟踪迅速。     

基于交通流特征的可变信息板布局优化方法

为了引导交通流的合理分布并确定城市路网中可变信息板的布局方案,本文提出了一种基于路段交通流特征信息量评估的可变信息板布局优化方法。利用图论对城市路网进行描述,建立了基于信息熵的路段交通流特征信息量评估模型。并结合实际路网的拓扑结构特性,设计了可变信息板布局方案的初步生成方法。12节点的网络实例验证显示:该布局方法是有效的,且便于交通管理者所理解。同时,提出的交通流特征提取方法具有较强的应用性,可为道路规划与安全评估提供基础信息。     

道路交通网络可靠性研究综述

文章是对道路交通网络可靠性研究的综述，阐述了连通可靠性、行程时间可靠性及容量可靠性的基本概念。介绍了道路交通网络可靠性的研究概况，在分析存在问题的基础上提出了研究方向。     

城市交通拥堵的街区缓冲定价模型及其仿真

随着城市机动车保有量的不断增长,城市主干路网供给能力出现严重不足,适当开放一些封闭街区并进行拥堵收费可以作为缓解主干路网交通压力的一项重要措施。针对城市主干路的交通拥堵问题,以区域路网车辆整体运行时间最短为优化目标,以缓冲街区的拥堵收费价格为决策变量,以交通弹性需求和动态分配以及缓冲街区路网饱和度等为限制条件,建立了缓冲街区定价优化模型,并给出了基于VISSIM软件的仿真求解流程。通过实例仿真结果表明,开放附近街区缓冲并采用模型给出的最优定价方案,既可以分担主干路部分车流从而保障了主干路通畅运行,又不超过缓冲区容量限制,提高了整体路网的运行效率。     

模糊控制算法在干线信号绿波控制中的应用研究——以虎门镇连升路为例

从交通信号控制的角度，对城市干道的交通信号控制策略及其控制优化参数（周期时长、绿信比、相位差）进行分析，并结合虎门镇连升路的交通状况，采用模糊控制方法实现城市交通干道的优化协调控制。通过VISSIM软件仿真，分析对连升路分别采用模糊协调控制方案、传统数解法协调控制方案及单点控制方案的效果并进行比较，结果表明模糊协调控制方案明显优于其他两种方法。     

On glioblastoma and the search for a cure: where do we stand?

Although brain tumours have been documented and recorded since the nineteenth century, 2016 marked 90 years since Percival Bailey and Harvey Cushing coined the term “glioblastoma multiforme”. Since that time, although extensive developments in diagnosis and treatment have been made, relatively little improvement on prognosis has been achieved. The resilience of GBM thus makes treating this tumour one of the biggest challenges currently faced by neuro-oncology. Aggressive and robust development, coupled with difficulties of complete resection, drug delivery and therapeutic resistance to treatment are some of the main issues that this nemesis presents today. Current treatments are far from satisfactory with poor prognosis, and focus on palliative management rather than curative intervention. However, therapeutic research leading to developments in novel treatment stratagems show promise in combating this disease. Here we present a review on GBM, looking at the history and advances which have shaped neurosurgery over the last century that cumulate to the present day management of GBM, while also exploring future perspectives in treatment options that could lead to new treatments on the road to a cure.     

城市浅埋近接桩基客运专线隧道施工方案研究

依托成绵乐客运专线机场路隧道下穿成都市蓝天立交工程，采用有限差分软件FLAC3D进行三维数值模拟分析。主要从隧道开挖所造成的地表沉降、桩基下沉量以及桩基端部水平位移差值这三个方面进行研究。研究结果表明：暗挖施工方案明显优于明挖施工方案。研究成果为既有立交桥的正常运营以及机场路隧道施工的顺利进行提供了保证，又可为相似工程提供参考。     

电动助力转向系统的建模及其全工况控制

将电动助力转向系统模型、轮胎模型以及非线性整车模型联系起来，建立完整的汽车转向动力学模型。针对EPS转向、回正、阻尼三种不同的工况，采用自适应模煳PID扣PID控制算法对EPS分刺进行了助力、回正、阻尼控制。仿真结果表明：所设计酶动力特性比较好的解决了转向轻便性和路感的矛盾，回正控制改善了车辆低速对低速时正性，抵制了车辆高速时的回正超调现象，阻尼控制能够有效的抑制路面的高频干扰，提高了汽车高速直线行驶的稳定性。     

商用车ABS预测控制方法研究

针对商用车制动过程中存在的强烈非线性和模型不确定性问题,建立了整车七自由度转向制动状态空间模型,提出了一种非线性连续预测控制方法,设计了基于滑移率的ABS非线性预测控制器.在控制器设计中,利用泰勒级数展开对系统状态进行适当的截尾处理,获得了系统预测模型,并将ABS路面识别算法引入参考轨迹设计,提出了多路面下的参考轨迹模型.当路况发生变化时,参考轨迹也发生相应的变化,而且在系统中引入了积分反馈,以增强系统的鲁棒性.仿真研究表明,当ABS存在建模误差、载荷变化和干扰时,该非线性预测控制器仍能够获得良好的动态响应和鲁棒性.     

Linear signal extraction with intervention techniques in non-linear time series

Seasonal adjustment is performed in some data-producing agencies according to the ARIMA-model-based signal extraction theory. A stochastic linear process parametrized in terms of an ARIMA model is first fitted to the series, and from this model the models for the trend, cycle, seasonal, and irregular component can be derived. A spectrum is associated to every component model and is used to compute the optimal Wiener–Kolmogorov filter. Since the modelling is linear, prior linearization of the series with intervention techniques is performed. This paper discusses the performance of linear signal extraction with intervention techniques in non-linear processes. In particular, the following issues are discussed: (1) the ability of intervention techniques to linearize time series which present non-linearities; (2) the stability of the linear projection giving the components estimators under non-linear misspecifications; (3) the capacity of the WK filter to preserve the linearity in some components and the non-linearities in others. Copyright © 1998 John Wiley & Sons, Ltd.     

基于图像式行驶记录仪的汽车-自行车交通冲突特性研究

汽车与自行车事故在我国交通事故总数中占有重要比例。为了研究汽车与自行车交通冲突／事故特性，本文选用50辆出租车，利用图像式汽车行驶记录仪在北京市开展了为期一年的交通冲突调查，从冲突类型、冲突时间、冲突地点及交通控制方式、冲突车速及交通流、驾驶员视线遮挡等方面综合分析汽车一自行车冲突特性，研究结果对道路交通安全管理、道路设计及事故预防技术具有重要的意义。     

Short‐term prediction of motorway travel time using ANPR and loop data

Travel time is a good operational measure of the effectiveness of transportation systems. The ability to accurately predict motorway and arterial travel times is a critical component for many intelligent transportation systems (ITS) applications. Advanced traffic data collection systems using inductive loop detectors and video cameras have been installed, particularly for motorway networks. An inductive loop can provide traffic flow at its location. Video cameras with image‐processing software, e.g. Automatic Number Plate Recognition (ANPR) software, are able to provide travel time of a road section. This research developed a dynamic linear model (DLM) model to forecast short‐term travel time using both loop and ANPR data. The DLM approach was tested on three motorway sections in southern England. Overall, the model produced good prediction results, albeit large prediction errors occurred at congested traffic conditions due to the dynamic nature of traffic. This result indicated advantages of use of the both data sources. Copyright © 2008 John Wiley & Sons, Ltd.     

若尔盖郎川公路建设区有毒有害植物扩散及生态安全性评价

通过大量的野外考察和文献资料分析,研究了朗川公路建设区沿线天然草地有毒有害植物种类、分布、群落结构及安全性。结果表明,由于人为干扰改变了天然植物群落物种间的竞争格局,具有较强竞争力的有毒有害物种得以扩散,在群落中作用增强,在群落中优势度逐渐上升。在各等级样方中,Shannon-Wiener物种多样性指数和Pielou均匀度指数随着有毒有害物种分盖度的增加呈现出先增后减再回升的趋势,Simpson优势度指数则随着有毒有害物种的分盖度增加而逐渐降低。此外,工程建设中采取草皮移植措施在一定程度上取得了成效,已恢复的边坡群落比较稳定,根据不同研究结果表明割取草皮厚度及大小与草皮恢复后的植物群落结构密切相关。     

公路大件运输安全管理系统研究

针对公路大件运输过程中，沿途弯道、横坡、纵坡、桥梁等复杂的道路状况，设计并开发了一种基于C／S架构的公路大件运输安全管理系统，以保障公路大件运输的安全性和可靠性。在分析系统体系结构特点的基础上，对系统数据库和客户端软件分别进行设计，并采用VB开发工具进行开发，实现系统各项功能。最后通过在公路大件运输企业的实际运用，证明了该系统的科学性与有效性。     

重型商用车驾驶室悬置系统参数匹配研究

建立了驾驶室悬置系统的多刚体模型和刚柔耦合模型。通过道路试验得到仿真所需要的激励，并验证了模型的正确性。以垂直方向加权加速度均方根值为评价目标，在频域里运用正交试验技术对悬置系统的刚度阻尼进行了匹配。最后在时域里分析匹配后悬置动扰度的变化，结果表明：匹配方案有效、可行。     

Induced pluripotent stem cells for cardiac repair

Myocardial stem cell therapies are emerging as novel therapeutic paradigms for myocardial repair, but are hampered by the lack of sources for autologous human cardiomyocytes. An exciting development in the field of cardiovascular regenerative medicine is the ability to reprogram adult somatic cells into pluripotent stem cell lines (induced pluripotent stem cells, iPSCs) and to coax their differentiation into functional cardiomyocytes. This technology holds great promise for the emerging disciplines of personalized and regenerative medicine, because of the ability to derive patient-specific iPSCs that could potentially elude the immune system. The current review describes the latest techniques of generating iPSCs as well as the methods used to direct their differentiation towards the cardiac lineage. We then detail the unique potential as well as the possible hurdles on the road to clinical utilizing of the iPSCs derived cardiomyocytes in the emerging field of cardiovascular regenerative medicine.     

Variance intervention

Variance intervention is a simple state-space approach to handling sharp discontinuities of level or slope in the states or parameters of models for non-stationary time-series. It derives from earlier procedures used in the 1960s for the design of self-adaptive, state variable feedback control systems. In the alternative state-space forecasting context considered in the present paper, it is particularly useful when applied to structural time series models. The paper compares the variance intervention procedure with the related ‘subjective intervention’ approach proposed by West and Harrison in a recent issue of the Journal of Forecasting, and demonstrates it efficacy by application to various time-series data, including those used by West and Harrison.