An investigation of incident frequency,duration and lanes blockage for determining traffic delay

Traffic delay caused by incidents is closely related to three variables: incident frequency, incident duration, and the number of lanes blocked by an incident that is directly related to the bottleneck capacity. Relatively, incident duration has been more extensively studied than incident frequency and the number of lanes blocked in an incident. In this study, we provide an investigation of the influencing factors for all of these three variables based on an incident data set that was collected in New York City (NYC). The information about the incidents derived from the identification can be used by incident management agencies in NYC for strategic policy decision making and daily incident management and traffic operation. In identifying the influencing factors for incident frequency, a set of models, including Poisson and Negative Binomial regression models and their zero‐inflated models, were considered. An appropriate model was determined based on a model decision‐making tree. The influencing factors for incident duration were identified based on hazard‐based models where Exponential, Weibull, Log‐logistic, and Log‐normal distributions were considered for incident duration. For the number of lanes blocked in an incident, the identification of the influencing factors was based on an Ordered Probit model which can better capture the order inherent in the number of lanes blocked in an incident. As identified in this study, rain is the only factor that significantly influenced incident frequency. For incident duration and the number of lanes blocked in an incident, various factors had significant impact. As concluded in this study, there is a strong need to identify the influencing factors in terms of different types of incidents and the roadways where the incidents occured.     

E-TYPE雕塑

每年夏天的英国古德伍德速度节(GoodwoodFestival of Speed)上,最大的设计亮点是Goodwood House前的雕塑。在过去的十年间,这块艺术宝地一直被英国著名艺术家兼设计师Gerry Judah占领,今年也不例外。这里矗立的是一尊高达28米的捷豹E-Type,以此来庆祝此款跑车诞生50     

Data-driven State-of-Charge estimator for electric vehicles battery using robust extended Kalman filter

An accurate battery State-of-Charge (SoC) estimation method is one of the most significant and difficult techniques to promote the commercialization of electric vehicles. This paper tries to make two contributions to the existing literatures through a robust extended Kalman filter (REKF) algorithm. (1) An improved lumped parameter battery model has been proposed based on the Thevenin battery model and the global optimization-oriented genetic algorithm is used to get the optimal polarization time constant of the battery model. (2) A REKF algorithm is employed to build an accurate data-driven based robust SoC estimator for a LiFePO4 lithium-ion battery. The result with the Federal Urban Driving Schedules (FUDS) test shows that the improved lumped parameter battery model can simulate the dynamic performance of the battery accurately. More importantly, the REKF based SoC estimation approach makes the SoC estimation with high accuracy and reliability, it can efficiently eliminate the problem of accumulated calculation error and erroneous initial estimator state of the SoC.     

Climate–ocean variability and Pacific hake: A geostatistical modeling approach

Climate forcing of the California Current has been known to impact the distribution and abundance of a number of local fish populations, but the mechanisms involved remain poorly understood. Climate metrics such as the Pacific Decadal Oscillation (PDO) and the El Niño Southern Oscillation (ENSO) are usually used to represent climate processes and direct links are made between climate forcing and production variability. This involves aggregation of impacts across large spatial scales and range of species. However, fluctuations in productivity are often the result of changes in physical habitat. In order to fully understand the relationship between climate and productivity, habitat changes should be addressed. In this study we use a geostatistical approach to quantify adult Pacific hake habitat during different climate regimes. Several authors have suggested that the distribution and intensity of the sub-surface poleward flow (the undercurrent) plays a key role in defining adult hake habitat along the west coast of North America. Here we build a model designed to predict hake habitat distribution in space based on sub-surface poleward flow distribution and bottom depth. Our results show that hake habitat expands in 1998 El Niño year compared to 1995. Given the important predatory role that hake plays in the CC, the amount and distribution of adult hake habitat has large implications for the Pacific Northwest food web and could thus serve as an ecosystem indicator representing important physical–biological interactions. Spatially based ecosystem indicators such as the one we develop here address two important yet neglected areas in the ‘Ecosystem Indicators debate’: the importance of developing metrics explicitly representing spatial and environmental processes shaping ecosystem structure. Without these, our power to fully describe ecosystems will be limited.     

Late Holocene history of the rainfall in the NW Iberian peninsula—Evidence from a marine record

This study reconstructs climatic variability over the last 4700 yr in the NW Iberian Peninsula on the basis of lithological, sedimentological, biogeochemical, micropaleontological (diatoms and biosiliceous compounds) and AMS ¹⁴C analyses conducted in a gravity core retrieved from the Galician continental shelf. The core was recovered at the Galicia Mud Patch, a muddy sedimentary body highly influenced by the terrestrial supply of the Miño and Douro rivers, and thus controlled by the rainfall variations over the catchment area. River plume transports the lithogenic and continental-derived compounds to the shelf area allowing us to recognize several periods of terrestrial/marine influence. These periods are well correlated with the lithological units identified. Coarser sediments, high values of Ca/Al, low values of Fe, Al and lithogenic Si (LSi) are representative of the marine-influenced periods. These stages are related to dry conditions and winds coming from the NE under a NAO positive-like phase.Terrestrial-influenced stages are characterized by muddy sediments, with high content of Fe, Al and LSi, freshwater and benthic diatoms, continental-derived organisms (crysophycean cysts and phytoliths) and high amount of land-derived organic matter as reported by the C/N ratios. The influence of NAO positive- and NAO negative-like periods and solar activity are the two mechanisms quoted to explain the climatic variability during the last 4700 years.Proxies for the lithogenic input and terrigenous content (non-organic material) show an increase at around 2000–1800 cal. yr BP, linked to the warmer conditions and high precipitation patterns during the Roman Warm Period, and soil erosion due to forest degradation and other anthropic activities. A strong river flow event is recorded in shelf sediments during 800–500 cal. yr BP. A pervasive NAO negative-like period, and the high irradiance registered during the Grand Solar Maximum (GSM) controlled the precipitation and induced a high run-off and riverine influx during this event.     

且走且设计

要不要杯啤酒?我觉得周五下午很适合喝点啤酒。我们杂志在全球挑选IntersectionMan,Michael Young作为国际设计圈的主要人物之一,是当之无愧的典型。他生于英国,曾在比利时、冰岛、澳大利亚、中国台湾等地工作     

Residual circulation in the Ría de Muros (NW Spain): A 3D numerical model study

The residual circulation of the Ría de Muros, a large coastal embayment in NW Spain, are studied using a three-dimensional baroclinic finite-difference model. The driving forces considered by the model include the tide, winds, river inflows and density forcing at the open boundary. In situ data of current velocity and direction, water level, wind velocity and direction, river discharge, and temperature and salinity are used for model validation. Simulated and observed time series of water level and current velocity are in good agreement. Once validated, the model is applied to compute the residual circulation induced by the relevant agents of the ría hydrodynamics—the tide, an upwelling-favourable wind characteristic of spring and summer, a downwelling-favourable wind typical of winter, and freshwater inflows associated with high river runoff. The resulting residual circulation differ notably. The tide does not generate significant residual flows except in the inner ría. By contrast, winds and river discharges induce important residual flows throughout; in the middle and outer ría they generate a 3D residual circulation pattern which renders the conventional two-layer scheme of estuarine circulation too simplistic in this case. Thus, this first application of a 3D numerical model to the Ría de Muros sheds new light on its fundamental hydrodynamics.