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Search results for: TRAFFIC CONDITIONS
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An approach to improve the time efficiency of disjoint paths calculation
PublicationFailures of network elements can be appropriately dealt with by utilization of alternate disjoint paths to provide redirection of flows affected by failures of the respective working paths. Known approaches can be broadly divided by decision on backup paths installation into proactive and reactive mechanisms, as well as based on the scope of recovery actions into local and global rerouting. There are several important scenarios...
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Interlaboratory Test to Characterize the Cyclic Behavior of Bituminous Interlayers: An Overview of Testing Equipment and Protocols
PublicationThe performance assessment of multi-layered pavements strongly depends on the mechanical behavior of the interface between bituminous layers. So far, comprehensive studies have been carried out mainly using quasi-static laboratory tests focusing on the interlayer shear strength at failure. However, it is generally recognized that cyclic shear testing will lead to the determination of parameters which are more closely linked to...
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Evaluation of Street Lighting Efficiency Using a Mobile Measurement System
PublicationThe issue concerns the initial stage of work on a method for performing a rapid assessment of the energy efficiency and illuminance of a street lighting installation. The proposed method is based on simultaneous measurement of illuminance from three lux meters placed on the roof of the vehicle. The data are acquired in road traffic, while the vehicle is driving. The proposed solution will allow in the future to quickly and reproducibly...
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Assessment of the Influence of Road Infrastructure Parameters on the Behaviour of Drivers and Pedestrians in Pedestrian Crossing Areas
PublicationPedestrians are participants and, most likely, fatalities in every third road traffic accident in Poland. Over 30% of all fatalities on Polish roads are pedestrians. Accidents with pedestrians are very often the result of various factors related to the infrastructure and behaviour of pedestrians and drivers. The objective of the work was to assess driver and pedestrian behaviour in pedestrian crossing areas. The research also served...
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Reliable routing and resource allocation scheme for hybrid RF/FSO networks
PublicationSignificant success of wireless networks in the last decade has changed the paradigms of communication networks design. In particular, the growing interest in wireless mesh networks (WMNs) is observed. WMNs offer an attractive alternative to conventional cable infrastructures, especially in urban areas, where the cost of new installations is almost prohibitive. Unfortunately, the performance of WMNs is often limited by the cluttered...
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Car-sharing: The Impact on Metropolitan Spatial Structures
PublicationMany examples from the past show that new technologies designed to solve particular problems can also create side effects generating new problems. Some unforeseen or unwanted results may influence space use and spatial structures. Car-sharing is an invention to compete with car ownership. It drastically rise efficiency of car use, reducing the number of vehicles per users. Diffusion of car-sharing is going to accelerate in the...
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Poroelastic Low Noise Road Surfaces
PublicationNoise is one of the most important problems related to road traffic. During the last decades, noise emitted by engine and powertrain of vehicles was greatly reduced and tyres became a clearly dominant noise source. The paper describes the concept of low noise poroelastic road surfaces that are composed with mineral and rubber aggregate bound by polyurethane resin. Those surfaces have a porous structure and are much more flexible...
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Further development of the poroelastic road surface within the new Polish project SEPOR
PublicationRoad surfaces have a direct impact on noise generated by rolling tyres, the main and dominant source of noise of moving vehicles. Road surface texture, porosity and stiffness/elasticity govern the pavement contribution to tyre/road noise the most. An experimental PoroElastic Road Surface (PERS) is a wearing course with a high content of interconnected voids (pores) and with an elastic behavior due to the use of small particles...
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A Study of Transport Behaviour of Academic Communities
PublicationAn important challenge to achieving sustainable university campuses is ensuring that the academic community makes sustainable transport choices. The objective of this study was to investigate the daily commuting patterns, identify the potential for change, and determine the factors and criteria affecting the transport decisions of academic communities of two universities located in Gdansk, Poland. This paper summarizes the results...
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Social media and efficient computer infrastructure in smart city
PublicationSocial media require an efficient infrastructures of computer and communication systems to support a smart city. In a big city, there are several crucial dilemmas with a home and public space planning, a growing population, a global warming, carbon emissions, a lack of key resources like water and energy, and a traffic congestion. In a smart city, we expect an efficient and sustainable transportation, efficient management of resources...
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Interlaboratory Test to Characterize the Cyclic Behavior of Bituminous Interlayers: An Overview of Testing Equipment and Protocols
PublicationThe performance assessment of multi-layered pavements strongly depends on the mechanical behavior of the interface between bituminous layers. So far, comprehensive studies have been carried out mainly using quasi-static laboratory tests focusing on the interlayer shear strength at failure. However, it is generally recognized that cyclic shear testing will lead to the determination of parameters which are more closely linked to...
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Wireless Link Selection Methods for Maritime Communication Access Networks—A Deep Learning Approach
PublicationIn recent years, we have been witnessing a growing interest in the subject of communication at sea. One of the promising solutions to enable widespread access to data transmission capabilities in coastal waters is the possibility of employing an on-shore wireless access infrastructure. However, such an infrastructure is a heterogeneous one, managed by many independent operators and utilizing a number of different communication...
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Ultra Low Noise Poroelastic Road Surfaces
PublicationNoise is one of the most important environmental problems related to road traffic. During the last decades, the noise emitted by the engines and powertrains of vehicles was greatly reduced and tires became a clearly dominant noise source. The article describes the concept of low noise poroelastic road surfaces that are composed of mineral and rubber aggregate bound by polyurethane resin. Those surfaces have a porous structure and...
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ROSANNE Project: New Procedure for Noise Characterisation of Road Surfaces in Europe
PublicationROSANNE is a collaborative project in the 7th EU Framework Programme which aims at harmonising measurement methods for skid resistance, noise emission and rolling resistance of road pavements as a preparation for standardization. The project started in November 2013 and is developing and improving standards in the field of working group CEN/TC 227/WG 5. Regarding the influence of the pavement on the road traffic noise emission,...
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A Method for The Assessing of Reliability Characteristics Relevant to an Assumed Position-Fixing Accuracy in Navigational Positioning Systems
PublicationThis paper presents a method which makes it possible to determine reliability characteristics of navigational positioning systems, relevant to an assumed value of permissible error in position fixing. The method allows to calculate: availability , reliability as well as operation continuity of position fixing system for an assumed, determined on the basis of formal requirements - both worldwide and national, position-fixing accuracy....
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Comparison of pavement noise properties on selected road sections using different CPX measuring systems: self-powered vehicle and special test trailer
PublicationThe recently published ISO standard intended to measure the noise properties of road surfaces in a standardized method (ISO 11819-2:2017) precisely defines measurement procedure of the influence of road surface on traffic noise. According to it, two types of test vehicles may be utilized: a self-powered vehicle fitted with one or more test tyres and a trailer towed by a separate vehicle with one or more test tyres mounted on the...
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Optimization of Train Energy Cooperation Using Scheduled Service Time Reserve
PublicationThe main aim of the paper was to develop an innovative approach to the preliminary estimation possibility of train energy cooperation based on data from timetables, without traction calculations. The article points out the need to strive for sustainable and environmentally friendly transport. It was pointed out that rail transport using electric traction is one of the more ecological branches of transport. It also offers a number...
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Acoustic lifecycle study of the double-layer porous asphalt on E4 in Huskvarna, Sweden
PublicationIn 2010 a double-layer porous asphalt concrete (DPAC) pavement was constructed on the E4 motorway through the Swedish city Huskvarna. Earlier experience in Sweden indicated that it was feasible to obtain a high initial noise reduction but due to the widespread use of studded tires in winter, clogging and ravelling created losses of around 2 dB per year, with an expected acoustical lifetime of only 3 years. However, the improved...
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Analysis of the relationship between the length of eye fixation and the parameters of advertisements visible from the road
PublicationIn Poland, many advertising signs addressed to motorists are located along the roadside. Advertisements do not serve any traffic related purpose and can distract drivers making them less reliable and as a consequence, reduce road safety. The existing regulations only apply to the carriageway. The research is conducted as part of the RID project. The objective of the RID project is to create a "Manual for positioning roadside advertising...
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Enhancing Availability for Critical Services
PublicationTraditional approaches to provide classes of resilient service take the physical network availability as an input and then deploy redundancy and restoration techniques at various layers, often without full knowledge of mappings between layers. This makes it hard (and often inefficient) to ensure the high availability required by critical services which are typically a small fraction of the total traffic. Here, the innovative technique...
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Low noise poroelastic road pavements based on modified asphalt binder
PublicationTire/road noise is one of the most important environmental problems related to road traffic. As the most effective way to fight noise is reduction of sound emission from the source, a lot of work is being done to improve tire and road surfaces construction. This paper describes the first “road” results obtained within the SEPOR project, which is focused on developing a low noise poroelastic road surface based on bituminous binder....
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Urban scene semantic segmentation using the U-Net model
PublicationVision-based semantic segmentation of complex urban street scenes is a very important function during autonomous driving (AD), which will become an important technology in industrialized countries in the near future. Today, advanced driver assistance systems (ADAS) improve traffic safety thanks to the application of solutions that enable detecting objects, recognising road signs, segmenting the road, etc. The basis for these functionalities...
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Damage of a post-tensioned concrete bridge – Unwanted cracks of the girders
PublicationThe cracking of a post-tensioned T-beam superstructure, which was built using the incremental launching method, is analyzed in the paper. The problem is studied in detail, as specific damage was observed in the form of longitudinal cracks, especially in the mid-height zone of the girder at the interface of two assembly sections. The paper is a case study. A detailed inspection is done and non-destructive testing results of the...
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A risk comparison framework for autonomous ships navigation
PublicationMaritime autonomous surface ships (MASS) may operate in three predefined operational modes (OM): manual, remote, or autonomous control. Determining the appropriate OM for MASS is important for operators and competent authorities that monitor and regulate maritime traffic in given areas. However, a science-based approach to this respect is currently unavailable. To assist the selection of the proper OM, this study presents a risk-based...
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Identification of acoustic event of selected noise sources in a long-term environmental monitoring systems
PublicationABSTRACT Undertaking long-term acoustic measurements on sites located near an airport is related to a problem of large quantities of recorded data, which very often represents information not related to flight operations. In such areas, usually defined as zone of limited use, often other sources of noise exist, such as roads or railway lines treated is such context as acoustic background. Manual verification of such recorded data...
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Analysis of IMS/NGN Call Processing Performance Using Phase-Type Distributions Based on Experimental Histograms
PublicationThe paper describes our further research done with the proposed analytical and simulation traffic models of the Next Generation Network (NGN), which is standardized for delivering multimedia services with strict quality and includes elements of the IP Multimedia Subsystem (IMS). The aim of our models of a single IMS/NGN domain is to evaluate two standardized call processing performance parameters, which appropriate values are very...
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Impact of overloaded vehicles on load equivalency factors and service period of flexible pavements
PublicationOverloaded vehicles occur less frequently in comparison to properly loaded vehicles but due to their greater potential to cause damage they significantly contribute to the distress of pavement structure. As the studies show, the phenomena of vehicles overloading intensifies when the control of traffic is poor and the average percentage of overloaded vehicles on analyzed roads varies from 6% to 23%. The main goal of the ar-ticle...
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Comprehensive Comparison of a Few Variants of Cluster Analysis as Data Mining Tool in Supporting Environmental Management
PublicationA few variants of hierarchical cluster analysis (CA) as tool of assessment of multidimensional similarity in environmental dataset are compared. The dataset consisted of analytical results of determination of metals (Na, K, Ca, Sc, Fe, Co, Zn, As, Br, Rb, Mo, Sb, Cs, Ba, La, Ce, Sm, Hf and Th) in ambient air dried and kept alive, by the means of hydroponics, moss baskets collected in 12 locations on the area of Tricity (Poland)....
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Asphalt Overlay Enhancement with Fatigue High-Performing Multiaxial Geocomposite
PublicationThe use of gecomposite incorporating multiaxial geogrid and non-woven fabric of high bitumen retention in asphalt overlays results in the increase of life of the designed pavement structure. Such an approach can offer an opportunity to increase the fatigue life (higher traffic capacity) without the need to increase asphalt overlay thickness or to reduce the thickness of asphalt overlay without reduction of pavement life eventually....
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DETERMINATION OF OBJECTIVES FOR URBAN FREIGHT POLICY
PublicationBackground: Decisions regarding strategic planning of urban freight transport very often are based on superficial assumptions inadequately reflecting the actual character of encountered challenges. The trend may be observed to adapt isolated solutions without supporting measures and verification of expected outcomes. Selected urban freight solutions have a significant potential to alleviate transport related problems, but they...
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Dynamic coloring of graphs
PublicationDynamics is an inherent feature of many real life systems so it is natural to define and investigate the properties of models that reflect their dynamic nature. Dynamic graph colorings can be naturally applied in system modeling, e.g. for scheduling threads of parallel programs, time sharing in wireless networks, session scheduling in high-speed LAN's, channel assignment in WDM optical networks as well as traffic scheduling. In...
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Know your safety indicator – A determination of merchant vessels Bow Crossing Range based on big data analytics
PublicationEven in the era of automatization maritime safety constantly needs improvements. Regardless of the presence of crew members on board, both manned and autonomous ships should follow clear guidelines (no matter as bridge procedures or algorithms). To date, many safety indicators, especially in collision avoidance have been proposed. One of such parameters commonly used in day-to-day navigation but usually omitted by researchers is...
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Investigation into MPI All-Reduce Performance in a Distributed Cluster with Consideration of Imbalanced Process Arrival Patterns
PublicationThe paper presents an evaluation of all-reduce collective MPI algorithms for an environment based on a geographically-distributed compute cluster. The testbed was split into two sites: CI TASK in Gdansk University of Technology and ICM in University of Warsaw, located about 300 km from each other, both connected by a fast optical fiber Ethernet-based 100 Gbps network (900 km part of the PIONIER backbone). Each site hosted a set...
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Technical and Economic Analysis of the Implementation of Selected Variants of Road Investment
PublicationThe aim of the article is to analyze three variants of modernization and reconstruction of a road intersection, which in practice is the cause of numerous collisions and accidents. Detailed design solutions are presented for them. The aim of the analyses is to indicate an effective solution that, taking into account technical modifications of the road system elements, will ensure the functionality of the road system to the highest...
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The need for linear revitalization. Gdynia case
PublicationThe aim of the article is to discuss the need of defining and implementation of the linear revitalization - the new approach related to the revitalization processes. The results of the preliminary investigations indicate that this kind of revitalization seems to be an important tool supporting city management and planning, especially in cases of cities fragmentation - causing lack of physical, social, economic and ecological cohesion....
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Effects of Road Infrastructure on Pedestrian Safety
PublicationThe objective of the work was to identify risks for pedestrians that involve road infrastructure and roadside and to define how selected elements of geometry and traffic layout affect driver behaviour (speed on approaching pedestrian crossings). The results have helped to formulate recommendations on pedestrian crossing design. The research included an analysis of 2013-2017 statistics to identify the...
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Construction of a simulation model of goods delivery in international road transportation taking into account the functioning efficiency of logistics supply chain
PublicationThe object of this study is the process of goods delivery in international road transport using various types of logistics chains. The problem being solved is due to the need to develop recommendations for exporters of goods to reformat or design new supply chains during wartime. The expediency of organizing foreign trade operations by the cargo owners' own forces or with the involvement of enterprises providing logistics consulting...
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Disaster Resilience of Optical Networks: State of the Art, Challenges, and Opportunities
PublicationFor several decades, optical networks, due to their high capacity and long-distance transmission range, have been used as the major communication technology to serve network traffic, especially in the core and metro segments of communication networks. Unfortunately, our society has often experienced how the correct functioning of these critical infrastructures can be substantially hindered by massive failures triggered by natural...
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Determinants and effects of Poland’s road accidents in the context of the 2030 agenda for sustainable development – poviat level analysis for the years 2010-2019
PublicationThe objective of the research was to assess how selected factors influence road safety in Poland’s poviats. To that end, an analysis was conducted of road accident determinants and effects in the poviats in the years 2010-2019. The time horizon fits in with Goal 3.6. of Agenda 2030, which is to halve the number of global deaths and injuries from road traffic accidents by 2020. The article pres-ents the analysis results for the...
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Reduction of exceeding the guaranteed service time for external trucks at the DCT Gdańsk container terminal using a six sigma framework
PublicationPurpose The purpose of this research was to investigate ways to reduce the average amount of exceeded guaranteed service time for external trucks at Deepwater Container Terminal Gdańsk Sp z o.o. (DCT Gdańsk) via dosing the gate activities, in particular IN-Gate entry process of trucks carrying import/export/transit containers. Design/methodology/approach A Six Sigma methodology with the DMAIC methods along with the SIPOC chart,...
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Simulator for Performance Evaluation of ASON/GMPLS Network
PublicationThe hierarchical control plane network architecture of Automatically Switched Optical Network with utilization of Generalized Multi-Protocol Label Switching protocols is compliant to next generation networks requirements and can supply connections with required quality of service, even with incomplete domain information. Considering connection control, connection management and network management, the controllers of this architecture...
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Advanced Bayesian study on inland navigational risk of remotely controlled autonomous ship
PublicationThe arise of autonomous ships has necessitated the development of new risk assessment techniques and methods. This study proposes a new framework for navigational risk assessment of remotely controlled Maritime Autonomous Surface Ships (MASS). This framework establishes a set of risk influencing factors affecting safety of navigation of a remotely-controlled MASS. Next, model parameters are defined based on the risk factors, and...
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Katedra Inżynierii Drogowej. Zakład Budowy Dróg.
PublicationDepartment of Highway Engineering is divided into two divisions: Road Construction Division and Traffic Engineering Division. The head of Road Construction Division is Prof. J. Judycki. There are nine members of division: professor, three PhD, two MSc, two technicians and secretary. The main areas of research activities are: analysis of flexible, semi-rigid and rigid pavements, resistance of asphalt pavement to permanent deformation,...
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APPLICATION OF CHEMOMETRIC ANALYSIS TO THE STUDY OF SNOW AT THE SUDETY MOUNTAINS, POLAND
PublicationSnow samples were collected during winter 2011/2012 in three posts in the Western Sudety Mountains (Poland) in 3 consecutive phases of snow cover development, i.e. stabilisation (Feb 1st), growth (Mar 15th) and its ablation (Mar 27th). To maintain a fixed number of samples, each snow profile has been divided into six layers, but hydrochemical indications were made for each 10 cm section of core. The complete data set was subjected...
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Study on the prevalence of mobile phone use by car drivers – the case of Poland
Publication: Distracted driving is a significant factor affecting road safety and it can occur as a result of using mobile phones while driving. The aim of the current research is to present the prevalence of mobile phone use by Polish car drivers, based on the roadside and online survey. The field study showed that 11.6% of 1867 drivers were using mobile phones while being in motion and 26.1% of 203 drivers when stopped in front of traffic...
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Modal Analysis of a Steel Radial Gate Exposed to Different Water Levels
PublicationWith the increase in water retention needs and planned river regulation, it might be important to investigate the dynamic resistance of vulnerable elements of hydroelectric power plants, including steel water locks. The most frequent dynamic loads affecting hydroengineering structures in Poland include vibrations caused by heavy road and railway traffic, piling works and mining tremors. More destructive dynamic loads, including...
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Calibration of acoustic vector sensor based on MEMS microphones for DOA estimation
PublicationA procedure of calibration of a custom 3D acoustic vector sensor (AVS) for the purpose of direction of arrival (DoA) estimation, is presented and validated in the paper. AVS devices working on a p-p principle may be constructed from standard pressure sensors and a signal processing system. However, in order to ensure accurate DoA estimation, each sensor needs to be calibrated. The proposed algorithm divides the calibration process...
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Blood concentrations of a new psychoactive substance 4-chloromethcathinone (4-CMC) determined in 15 forensic cases
PublicationPurpose: The 4-chloromethcathinone (4-CMC) is a synthetic derivative of cathinone and belongs to new psychoactive substances. Neither data on the effects of 4-CMC on the human body, nor on nontoxic, toxic and lethal concentrations in biological materials have been published in the literature. This paper describes the results of an analysis of the blood concentrations of 4-CMC determined in 15 forensic cases related to nonfatal...
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Non-Satellite Broadband Maritime Communications for e-Navigation Services
PublicationThe development of broadband network access technologies available to users on land has triggered a rapid expansion of a diverse range of services provided by terrestrial networks. However, due to limitations of digital communication technologies in the off-shore area, the maritime ICT systems evolution so far has not followed that trend. Despite the e-navigation initiative defining the set of Maritime Services, the progress in...
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Determination of Vehicles Load Equivalency Factors for Polish Catalogue of Typical Flexible and Semi-rigid Pavement Structures
PublicationThe new Polish Catalog of Typical Flexible and Semi-rigid Pavement Structures was introduced to use in practice in 2014. Much of works were focused on actualization of vehicles load equivalency factors. For this purpose data delivered from weigh-inmotion were analyzed. Four methods of determination of load equivalency factors for pavement structure design were compared. The analysis showed that fourth power equation, AASHTO 1993...