scholarly journals Lighting requirements for pedestrian crossings – positive contrast

2019 ◽  
Vol 262 ◽  
pp. 05015 ◽  
Author(s):  
Piotr Tomczuk ◽  
Kazimierz Jamroz ◽  
Tomasz Mackun ◽  
Marcin Chrzanowicz
Keyword(s):  
Positive Contrast ◽  
Weather Conditions ◽  
Luminance Contrast ◽  
Night Vision ◽  
Traffic Situation ◽  
Road Accidents ◽  
Artificial Lighting ◽  
Pedestrian Crossing ◽  
Technical Solutions

For many years now in Poland there has been a large number of road accidents at pedestrian crossings during night periods [5, 11]. One of the technical solutions that can improve this condition is the use of proper lighting for pedestrian crossings. The designated pedestrian crossing should be visible in different weather conditions and at different times of the day. In case of night vision restrictions use artificial lighting of pedestrian crossings. At the same time, lighting of pedestrian crossings should ensure: proper conditions for the driver to recognise the traffic situation and observe the pedestrian's silhouette, and for the pedestrian to observe the surroundings, pedestrian crossings and upcoming vehicles. The article gives an opinion on the proposal of lighting requirements for dedicated luminaires, realizing positive luminance contrast, used in the area of pedestrian crossings together with the proposed measurement grids. Quantitative requirements have been formulated taking into account the gradation of lighting classes resulting from the current lighting standard.

Corrective Solutions for the Shaft with Flange Used for Fixing the Blade on a 5 kW Wind Turbine to Withstand Extreme Weather Conditions

2014 ◽  
Vol 1029 ◽  
pp. 118-123
Author(s):  
Rodica Bădărău ◽  
Teodor Miloş ◽  
Ilare Bordeaşu ◽  
Adrian Bej
Keyword(s):  
Mechanical Strength ◽  
Wind Turbine ◽  
Weather Conditions ◽  
Extreme Weather ◽  
Original Solution ◽  
Root Area ◽  
Materials Used ◽  
Improved Design ◽  
The Right ◽  
Technical Solutions

The paper presents a case study on the original solution of a flange shaft as part of the root area of a 5 kW wind turbine blade. There were analyzed the causes that led to the shaft breakage under wind loadings in extreme weather conditions, and consequently technical solutions have been searched in order to improve the shaft design making it more reliable as mechanical strength at extreme wind loadings. The flange shaft is a welded subassembly that keeps the blades attached to the rotor hub. The first part of the paper consists in an analysis referring the loading status, the materials used for blade manufacturing, the identification of critical areas where the breaking was initiated and also the causes for which the materials assumed and specified in the technical design and manufacturing technology failed under loading at wind gusts of about 30 m/sec. Based on this preliminary analysis, the second part of the paper presents the technical solutions which were considered in reference to the materials and the improved design concept aiming to provide the right mechanical strength necessary to withstand specific wind loadings in extreme weather conditions.

LASER FLUOROSENSOR DEMONSTRATION FLIGHTS AROUND THE SOUTHERN COAST OF NEWFOUNDLAND

2005 ◽  
Vol 2005 (1) ◽  
pp. 1001-1005 ◽  
Author(s):  
Carl E. Brown ◽  
Mervin F. Fingas ◽  
Richard Marois
Keyword(s):  
Remote Sensing ◽  
North Atlantic ◽  
Real Life ◽  
Weather Conditions ◽  
Night Vision ◽  
Laser Fluorescence ◽  
Late Winter ◽  
Southern Coast ◽  
Oil Platforms ◽  
The North

ABSTRACT Several oil spill remote sensing flights were conducted by Environment Canada off the Southern coast of Newfoundland, Canada in late February, early March 2004. These flights were undertaken to demonstrate the capabilities of the Scanning Laser Environmental Airborne Fluorosensor (SLEAF) in real-life situations in the North Atlantic and Newfoundland coastal regions in late winter weather conditions. Geo-referenced infrared, ultraviolet, color video and digital still imagery was collected along with the laser fluorosensor data. Brief testing of a Generation III night vision camera was also conducted. Flights were conducted in the shipping lanes around the Newfoundland coast, out to the Hibernia and Terra Nova oil platforms and over known oil seep areas. Details of the analysis of laser fluorescence data collected during these flights will be presented along with a summary of the remote sensing flights.

scholarly journals A model for weather-related traffic variations and accident probabilities on roads

2021 ◽  
Author(s):  
Nico Becker ◽  
Henning Rust ◽  
Uwe Ulbrich
Keyword(s):  
Linear Models ◽  
Road Traffic ◽  
Weather Conditions ◽  
Radar Data ◽  
Traffic Volume ◽  
Road Accidents ◽  
Wind Speeds ◽  
Predictive Skill ◽  
Accident Probability ◽  
Low Cloud

<p>Weather conditions affect both road traffic volume and the probability of road accidents. The aim of this study is improve the understanding of both effects as well as their interactions. In a first step, we develop generalized linear models for hourly road traffic counts at 1400 traffic stations on German federal roads and highways. It is distinguished between different vehicle types, including motorbikes, cars, delivery vans and trucks. Different meteorological variables are derived from reanalysis and radar data. The impacts of these variables on the predictive skill of the models is analyzed. In particular models for motorbike counts show large improvements, if meteorological predictors are added to the model. At weekends in the afternoon the mean squared errors of modeled motorbike counts are reduced by up to 60%. Temperatures around 25°C, no precipitation, low cloud cover and low wind speeds lead to the highest motorbike counts. In a second step, the information derived from the traffic models is used to improve models for hourly probabilities of road accidents. These models are based on police reports, which are available at the level of administrative districts, and can now explicitly take traffic volume into account. It is shown that in particular winter conditions like precipitation and freezing temperatures lead to a significant increase in accident probability. Especially the probabilities of roadway departures show an increase under such conditions. The models presented in this study are suitable for the integration in risk-based warning systems and have the potential to improve risk perception and behavior of warning recipients.</p>

scholarly journals Intelligent Accident Prevention in VANETs

2019 ◽  
Vol 8 (2) ◽  
pp. 2401-2405
Keyword(s):  
Road Safety ◽  
Ad Hoc Network ◽  
Ad Hoc ◽  
Weather Conditions ◽  
Accident Prevention ◽  
Road Accidents ◽  
Human Errors ◽  
The Road ◽  
On The Road ◽  
Nearest Neighbour Classifier

Accident prevention has always been an important issue for governments and car manufacturers across the world. Roughly 1.5 million people are killed in road accidents annually in India. The primary causes of accidents are broken and weathered roads, hazardous weather conditions, as well as human errors such as over speeding, distracted driving, and not following road safety rules. The traffic police work hard to enforce strict rules and maintain accident-free roads, but this hasn’t proven to be efficient. A vehicular ad hoc network (VANET), as the name says, is a network consisting of nodes. These nodes depict vehicles on the road. This project aims to use this technology with K-Nearest Neighbour Classifier (KNN) to create a prototype of a system which can notify drivers of an impending accident caused by forward collisions, rear collision etc., thus enabling them to take immediate action and prevent it.

scholarly journals Roadway Lighting’s Effect on Pedestrian Safety at Intersection and Midblock Crosswalks

2021 ◽  
Author(s):  
Rajaram Bhagavathula ◽  
◽  
Ronald Gibbons ◽  
Andrew Kassing ◽  
◽  
...  
Keyword(s):  
Pedestrian Detection ◽  
Positive Contrast ◽  
Pedestrian Safety ◽  
Light Level ◽  
Lighting Design ◽  
Visual Performance ◽  
Light Levels ◽  
Disability Glare ◽  
Safety Countermeasures ◽  
Pedestrian Crossing

This study evaluates the visual performance of four intersection lighting designs and five midblock crosswalk lighting designs along with two pedestrian safety countermeasures (rectangular rapid flashing beacons and flashing signs) at three light levels. The study involved a pedestrian detection task, which was completed at night on a realistic roadway intersection and a midblock crosswalk. The results from the study showed that driver nighttime visual performance at intersection and midblock crosswalks was influenced by the lighting design and light level. Intersections should be illuminated to an average horizontal illuminance of 14 lux (1.3 fc). This light level ensures optimal visibility of pedestrians regardless of the lighting design (or luminaire layout) of the intersection. The average horizontal illuminance of 14 lux (1.3 fc) also increases the visibility of pedestrians when glare from oncoming vehicles is present. The 14 lux (1.3 fc) average horizontal illuminance is valid for all lighting designs evaluated except the lighting design that illuminated the exits of the intersection. When the exits of the intersection are illuminated, an average horizontal illuminance of 24 lux (2.2 fc) is needed to offset the disability glare from opposing vehicles. Midblock crosswalks should be illuminated to an average vertical illuminance of 10 lux (0.9 fc) to ensure optimal pedestrian visibility. Where overhead lighting is available, midblock crosswalk lighting designs that render the pedestrian in positive contrast are recommended. Where overhead lighting is not available, crosswalk illuminators can be used to illuminate midblock crosswalks. At night, pedestrian crossing treatments such as rectangular rapid flashing beacons and flashing signs should not be used for pedestrian visibility at midblock crosswalks. Pedestrians crossing treatments should be used in conjunction with overhead lighting or crosswalk illuminators at the established vertical illuminance to ensure optimal pedestrian visibility at midblock crosswalks.

Deep Visible and Thermal Camera-based Optimal Semantic Segmentation using Semantic Forecasting

2021 ◽  
pp. 1-10
Author(s):  
Vijay John ◽  
Seiichi Mita ◽  
Annamalai Lakshmanan ◽  
Ali Boyali ◽  
Simon Thompson
Keyword(s):  
Sensor Fusion ◽  
Weather Conditions ◽  
Semantic Segmentation ◽  
Autonomous Driving ◽  
Thermal Camera ◽  
Pedestrian Behavior ◽  
Semantic Map ◽  
Adverse Weather ◽  
Ablation Study ◽  
Pedestrian Crossing

Abstract Visible camera-based semantic segmentation and semantic forecasting are important perception tasks in autonomous driving. In semantic segmentation, the current frame's pixel level labels are estimated using the current visible frame. In semantic forecasting, the future frame's pixel-level labels are predicted using the current and the past visible frames and pixel-level labels. While reporting state-of-the-art accuracy, both of these tasks are limited by the visible camera's susceptibility to varying illumination, adverse weather conditions, sunlight and headlight glare etc. In this work, we propose to address these limitations using the deep sensor fusion of the visible and the thermal camera. The proposed sensor fusion framework performs both semantic forecasting as well as an optimal semantic segmentation within a multi-step iterative framework. In the first or forecasting step, the framework predicts the semantic map for the next frame. The predicted semantic map is updated in the second step, when the next visible and thermal frame is observed. The updated semantic map is considered as the optimal semantic map for the given visible-thermal frame. The semantic map forecasting and updating are iteratively performed over time. The estimated semantic maps contain the pedestrian behavior, the free space and the pedestrian crossing labels. The pedestrian behavior is categorized based on their spatial, motion and dynamic orientation information. The proposed framework is validated using the public KAIST dataset. A detailed comparative analysis and ablation study is performed using pixel-level classification and IOU error metrics. The results show that the proposed framework can not only accurately forecast the semantic segmentation map but also accurately update them.

Analysis of Impact of Tire Tread Groove Depth on Hydroplaning Risk Level

2012 ◽  
Vol 455-456 ◽  
pp. 1459-1467 ◽  
Author(s):  
Tang Zhi Liu ◽  
Bo Ming Tang ◽  
Hai Ying Li
Keyword(s):  
Fluid Dynamics ◽  
Weather Conditions ◽  
Groove Depth ◽  
Risk Level ◽  
Road Accidents ◽  
Safe Driving ◽  
Standing Water ◽  
Speed Range ◽  
Wet Weather ◽  
Different Parts

Hydroplaning ranks a maior inducement of wet-weather road accidents. By way of CFD (Computational Fluid Dynamics) approach, this paper frames a finite-element meta-models for rib tires ranging in groove depth, aiming to figure out the wheel water pressures on tires under different traveling conditions, and to find out water velocities of the different parts of the tire tread. Analysis shows that the action coverage of the high pressure induced by hydradynamic pressure is correlated with the thickness of standing water, and the grooves fail to drain as designed in case of total hydraplaning. Based on the outcomes of the experiments, this paper frames the relation formula between hydradynamic pressure and traveling velocity, standing water depth and tire tread groove depth, and thus gives recommendations on speed range in wet weather driving, and also on measures for safe driving in wet weather conditions.

Technical solutions for upgrading high rate and medium loaded activated sludge plants for nutrient removal

2000 ◽  
Vol 41 (9) ◽  
pp. 131-138 ◽  
Author(s):  
P. Chudoba ◽  
R. Pujol
Keyword(s):  
Activated Sludge ◽  
Total Nitrogen ◽  
Nutrient Removal ◽  
Nitrogen Concentration ◽  
Weather Conditions ◽  
High Rate ◽  
Aeration Tank ◽  
Optimum Level ◽  
Operational Mode ◽  
Technical Solutions

In order to meet the requirements for total nitrogen removal in sensitive area, as specified by the EC Standards, existing high-rate or medium loaded activated sludge plants treating only carbonaceous pollution have to be upgraded. Two attractive technical solutions are proposed. Depending on both the design and operational conditions of the activated sludge plants, all existing treatment facilities will be reused for nutrient removal with either an immobilized nitrifying system implemented directly in the existing activated sludge tank or with an additional up-flow nitrifying biofilter. Both technical solutions enable the effluent total nitrogen concentration to be as low as 10 mg TN/l. When a high or medium loaded activated sludge plant with primary settling tanks is designed for a HRT of more than five hours, the Pegazur immobilized carrier system can be implemented directly in the biological reactors. The existing aeration tank is divided into anoxic and aerated zones, and the nitrifying Biocubes are introduced in the aerated one. Such an upgraded activated sludge system (which did not nitrify before the upgrading) can reach a maximum eliminated loading rate of 0.5 kg NH4–N per m3 of aerated volume per day at 12°C. This solution was used to upgrade the 120,000 p.e. Bellozanne Sewage Treatment Works, Jersey, Channel Islands, UK. When an existing high rate activated sludge plant is designed for a HRT of less than five hours, the activated sludge tank can be transformed into a high-rate denitrifying anoxic reactor, coupled to a nitrifying Biofor up-flow filter. The high-rate anoxic sludge is continuously controlled by an ORP probe in order to ensure both the denitrifying conditions and recycle ratios are at their optimum level. This controlled operation and high water velocities applied to the nitrifying up-flow Biofor enable the operational mode to switch from dry weather conditions to wet weather conditions where the recycle of nitrified liquor is switched off and the high loaded anoxic sludge is temprarily aerated.

scholarly journals Assessing the Effects of the Road Surface and Weather Conditions on Road Safety

2019 ◽  
Vol 49 (3) ◽  
pp. 323-349 ◽  
Author(s):  
Marcin Budzyński ◽  
Agnieszka Tubis
Keyword(s):  
Road Safety ◽  
Significant Contribution ◽  
Weather Conditions ◽  
Road Surface ◽  
Road Accidents ◽  
Driver Behaviour ◽  
Safe Delivery ◽  
The Road ◽  
External Conditions

Abstract When transport is analysed for its safe delivery the focus is mainly on assessing the safety of roads and the risk of undesired events. These include road accidents, an occurrence which is relatively rare and random. Randomness means that accidents depend on several factors which are partly deterministic and partly. The authors conducted an assessment of how weather conditions affect the risk of an accident due to the factor’s significant contribution to road accidents. This case involves a combination of two sources of hazard: external conditions in the form of the weather which are beyond the driver’s control and anthropotechnical factors that address vehicle condition and driver behaviour controlled by the driver.

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