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Number of results: 28
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Abstract

The aim of the article was to determine the course of changes the urban space under the influence of tourism, on the example of selected areas in Cracow. A literature study, statistical data and field studies were used to explain the relationship between the growth of tourist movement and the development of the tourist space of this city. The impact of tourism on changes in public and private space use within Matejki Square and Pawia Street, in the neighbourhood of the historical zone (Old Town) and in the New Square at Kazimierz, was analysed. The conducted analysis showed three functional changes of the studied areas under the influence of the rapid tourist movement. They were transformed from residential-service to service-residential related to service of tourists (hotels, gastronomy, trade, entertainment). The urban space has been enriched with elements that increasing the tourist attractiveness of Cracow compared with other cities, for example, concerning spending free time (pubs, cafés, restaurants), and the new accommodation base near the city-centre. A lack of a zoning plan and development vision causes the helplessness of the local authorities in managing the tourist infrastructure development, which is reflected at the Kazimierz New Square.
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Abstract

Traffic related noise is currently considered as an environmental pollution. Paper presents results of multidirectional study attempting to serve urban traffic without the need to erect noise barriers interfering urban space. Initial concept of the road expansion included construction of 1000 m of noise barriers dividing city space. Improvement in the acoustic conditions after construction completion is possible due to the applied noise protection measures: vehicle speed limit, smooth of traffic flow, use of road pavement of reduced noise emission and the technical improvement of the tramway.
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Abstract

One of the basic parameters which describes road traffic is Annual Average Daily Traffic (AADT). Its accurate determination is possible only on the basis of data from the continuous measurement of traffic. However, such data for most road sections is unavailable, so AADT must be determined on the basis of short periods of random measurements. This article presents different methods of estimating AADT on the basis of daily traffic (VOL), and includes the traditional Factor Approach, developed Regression Models and Artificial Neural Network models. As explanatory variables, quantitative variables (VOL and the share of heavy vehicles) as well as qualitative variables (day of the week, month, level of AADT, the cross-section, road class, nature of the area, spatial linking, region of Poland and the nature of traffic patterns) were used. Based on comparisons of the presented methods, the Factor Approach was identified as the most useful.
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Abstract

The author investigated traffic flow quality on a new 2+1 long road bypass with an exceptionally high share of heavy vehicles in order to assess rational limits of heavy vehicle shares in traffic flow, dependent on the length of the 2+1 road and the number of passing segments in each direction. This paper presents the results of traffic flow quality analyses through the use of empirical and simulation methods for a single 2+1 road segment with additional passing lanes, as well as for the study of the entire section of the bypass – 2+1 road. Variables include analysis of travel speed distribution, platoon traffic, and amount of passing maneuvers. Results show that large passing demands lead to very high speeds (over 100 km/h) on segments with additional passing lanes. The conclusions include remarks related to the use and operation of 2+1 cross-sections with high shares of heavy vehicles.
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Abstract

Traffic classification is an important tool for network management. It reveals the source of observed network traffic and has many potential applications e.g. in Quality of Service, network security and traffic visualization. In the last decade, traffic classification evolved quickly due to the raise of peer-to-peer traffic. Nowadays, researchers still find new methods in order to withstand the rapid changes of the Internet. In this paper, we review 13 publications on traffic classification and related topics that were published during 2009-2012. We show diversity in recent algorithms and we highlight possible directions for the future research on traffic classification: relevance of multi-level classification, importance of experimental validation, and the need for common traffic datasets.
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Abstract

The paper shows a study on the relationship between noise measures and sound quality (SQ) features that are related to annoyance caused by the traffic noise. First, a methodology to perform analyses related to the traffic noise annoyance is described including references to parameters of the assessment of road noise sources. Next, the measurement setup, location and results are presented along with the derived sound quality features. Then, statistical analyses are performed to compare the measurement results and sound quality features. The included conclusions are focused on showing that the obtained loudness values, regardless of the used system, are similar in a statistical sense. Contrarily, sharpness, roughness and fluctuation strength values differ for the tools employed.
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Abstract

n the paper, the simulation PROP5 program with the road model defined as a noise source and road surroundings model, is used to predict the efficiency of noise protecting means for the chosen building. The appropriate models of verified accuracy have been chosen by comparison of the simulation results with field measurements (Walerian et al., 2010). Here, using the pre-tested simulation program, the possibility of acoustic climate improvement has been analyzed in the ranges of practical variations of the input parameters. The road parameters: its geometry (number of lanes and their positions) and traffic structure over lanes (vehicle flow rates and their average speeds) have been taken under consideration as changeable parameters, that could be corrected to obtain acoustical climate improvement. Moreover, an acoustical screen designing has been considered. The screen efficiency has been evaluated under conditions defined by the input parameters of the road and its surroundings.
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Abstract

In the paper, the simulation PROP5 program is used to predict the sound level in proximity of a road with defined surroundings. The simulation involves road geometry (number of lanes and their positions) and traffic structure (vehicle flow rates and their average speeds), with equivalent omnidirectional point sources representing vehicles. In Part I of the paper, the agreement between measurement and simulation results is tested to verify the accuracy degree of the applied models of a road, as a noise source and propagation throughout surrounding space. In Part II, using the pre-tested simulation program, the possibility of acoustic climate improvement has been analyzed.
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Abstract

Enhanced Traffic Management System (ETMS) stores all the information gathered by the Federal Aviation Administration (FAA) from aircraft flying in the US airspace. The data stored from each flight includes the 4D trajectory (latitude, longitude, altitude and timestamp), radar data and flight plan information. Unfortunately, there is a data quality problem in the vertical channel and the altitude component of the trajectories contains some isolated samples in which a wrong value was stored. Overall, the data is generally accurate and it was found that only 0.3% of the altitude values were incorrect, however the impact of these erroneous data in some analyses could be important, motivating the development of a filtering procedure. The approach developed for filtering ETMS altitude data includes some specific algorithms for problems found in this particular dataset, and a novel filter to correct isolated bad samples (named Despeckle filter). As a result, all altitude errors were eliminated in 99.7% of the flights affected by noise, while preserving the original values of the samples without bad data. The algorithm presented in this paper attains better results than standard filters such as the median filter, and it could be applied to any signal affected by noise in the form of spikes
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Abstract

Noise measurements have been carried out at eleven different sites located in three prominent cities of the Tarai region of India to evaluate the effectiveness of vegetation belts in reducing traffic noise along the roadsides. Attenuation per doubling of distance has been computed for each site and excess attenuation at different 1/3 octave frequencies has been estimated. The average excess attenuation is found to be approximately 15 dB over the low frequencies (200 Hz to 500 Hz) and between 15 dB to 20 dB over the high frequencies (8 kHz to 12.5 kHz). Over the critical middle frequencies (1-4 kHz), the average excess attenuation (between 10-15 dB) though not as high, is still significant, with a number of sites showing an excess attenuation of 15 dB or more at 1 kHz. The results indicate that sufficiently dense vegetation belts along the roadsides may prove as effective noise barriers and significant attenuation may be achieved over the critical middle frequencies (1-4 kHz).
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Abstract

The use of periodic structures as noise abatement devices has already been the object of considerable research seeking to understand its efficiency and see to what extent they can provide a functional solu- tion in mitigating noise from different sources. The specific case of sonic crystals consisting of different materials has received special attention in studying the influence of different variables on its acoustic performance. The present work seeks to contribute to a better understanding of the behavior of these structures by implementing an approach based on the numerical method of fundamental solutions (MFS) to model the acoustic behavior of two-dimensional sonic crystals. The MFS formulation proposed here is used to evaluate the performance of crystals composed of circular elements, studying the effect of varying dimen- sions and spacing of the crystal elements as well as their acoustic absorption in the sound attenuation provided by the global structure, in what concerns typical traffic noise sources, and establishing some broad indications for the use of those structures.
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Abstract

Missing traffic data is an important issue for road administration. Although numerous ways can be found to impute them in foreign literature (inter alia, the most effective method, that is Box-Jenkins models), in Poland, still only proven and simplified methods are applied. The article presents the analyses including an assessment of the completeness of the existing traffic data and works related to the construction of SARIMA model. The study was conducted on the basis of hourly traffic volumes, derived from the continuous traffic counts stations located in the national road network in Poland (Golden River stations) from the years 2005 – 2010. As a result, the proposed model was used to impute the missing data in the form of SARIMA (1.1,1)(0,1,1)₁₆₈. The newly developed model can be used effectively to fill in the missing required days of measurement for estimating AADT by AASHTO method. In other cases, due to its accuracy and laboriousness of the process, it is not recommended.
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Abstract

In recent years adverse processes of suburbanization have been observed in cities. It has become a serious challenge for urban and transport planners, as it influences largely the quality of space, the quality of life, and the cost of running the city. This paper is dedicated to travel models in areas serviced by a railway system, and is based on a real-life survey example of the Błonie community, a district belonging to the Warsaw metropolitan area. Research carried out in 2014 focused on combined travels behaviors recorded using GPS locators as well as quantitative research (volumes of users across various transport systems).
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Abstract

This paper presents an experimental system for remote communication between road users and traffic signs. Implemented solution consists of two modules: a transmitter (traffic sign), including novel system for remote waking-up by the passing vehicle with use of the quasi-passive (biased) diode detector circuit, and a receiver (vehicle), which is responsible for wake-up signaling and interpreting received messages. Both modules use Wi-Fi protocol operating in 2.4 GHz ISM band for sending data, and OOK signaling in 868 MHZ ISM band for sending wake-up signals. The paper provides theoretical analysis, description of design challenges and chosen solutions, and finally, laboratory measurements as well as the results of tests conducted in the systems’ target environment with a moving vehicle, confirming correct operation of the system.
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Abstract

Systems of road traffic parameters measurement play a key role in the process of road traffic control, its supervision as well as in gathering and processing information for statistical purposes. Expectations of users of such systems mainly concern automation and provision of measurement continuity, possibility of selection of the measured road traffic parameters and high accuracy along with reliability of obtained results. In order to meet the requirements set for such systems, at the Department of Instrumentation and Measurement of the AGH University of Science and Technology in Cracow a new prototype system of road traffic parameters measurement - Traffic-1 - has been constructed. The innovativeness of the solution is manifested in the structure of the system that can be modified by the user adequately to current measurement needs and in the used algorithms of signals processing. The work contains a brief description of the constructed system with particular focus on the used innovations that are the result of many years of research work of the designers.
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Abstract

An available bandwidth at a link is an unused capacity. Its measuring and/or estimation is not simple in practice. On the other hand, we know that its continuous knowledge is crucial for the operation of almost all networks. Therefore, there is a continuous effort in improving the existing and developing new methods of available bandwidth measurement and/or estimation. This paper deals with these problems. Network calculus terminology allows to express an available bandwidth in terms of a service curve. The service curve is a function representing a service available for a traffic flow which can be measured/estimated in a node as well as at an endto- end connection of a network. An Internet traffic is highly unpredictable what hinders to a large extent an execution of the tasks mentioned above. This paper draws attention to pitfalls and difficulties with application of the existing network calculus methods of an available bandwidth estimation in a real Internet Service Provider (ISP) network. The results achieved in measurements have been also confirmed in simulations performed as well as by mathematical considerations presented here. They give a new perspective on the outcomes obtained by other authors and on their interpretations.
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Abstract

The paper presents two theoretical models for traffic noise level distribution on curved horizontal roads. In the case of vehicles moving on a given route, one can consider, in terms of sound field, that the granular traffic is equivalent for short periods with a quasi-continuous noise flow. When computing and modelling the noise level generated by traffic on roads with complex trajectory, it is common to treat the route as a sum of small length road segments, each being assimilated with a linear noise source. This paper started from the assumption that the route can be decomposed into a sequence of linear and arc-shaped road segments, each of which is treated as a linear respectively curved noise source. An arc-shaped road segment is modelled by a tubular vibrating surface, of circular or rectangular section. In the case of rectangular section, the vibrating blade emits complex sounds on its both vertical sides and the generated sound field can be described more clearly, qualitatively and quantitatively, through intensity distribution. The theoretical models presented in the paper have direct application to the traffic noise prediction and noise maps drawing
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Abstract

Limited Traffic Zone (LTZ) is a planning strategy that is more and more adopted by municipalities in Europe to improve their environmental conditions. It consists in the prohibition for traditional vehicles to circulate in specific areas. Although the main aim is to tackle air pollution problems, positive effects are registered in terms of reduction of noise annoyance and in terms of improved “quality of life” if specific conditions are respected. On the other side under the drive of the global market, the number of circulating electric vehicles in urban sites is also increasing. In the next years we expect to experience a new and not well-known urban soundscape. In this paper is presented an overview of recent urban projects and policies that deal with noise control and how these experiences will match into the next years with the sound characteristics of new electric vehicles for private and public transportation.
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Abstract

The Traffic Flow Description (TFD) option of the IP protocol is an experimental option, designed by the Authors and described by the IETF’s Internet Draft. This option was intended for signalling for QoS purposes. Knowledge about forthcoming traffic (such as the amount of data that will be transferred in a given period of time) is conveyed in the fields of the option between end-systems. TFD-capable routers on a path (or a multicast tree) between the sender and receiver(s) are able to read this information, process it and use it for bandwidth allocation. If the time horizons are short enough, bandwidth allocation will be performed dynamically. In the paper a performance evaluation of an HD video transmission QoS assured with the use of the TFD option is presented. The analysis was made for a variable number of video streams and a variable number of TCP flows that compete with the videos for the bandwidth of the shared link. Results show that the dynamic bandwidth allocation using the TFD option better assures the QoS of HD video than the classic solution, based on the RSVP protocol.
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Abstract

Inductive loop sensors are widely used for detection of presence, measurement of parameters as well as classification of vehicles. Vehicle classification may be performed based on their magnetic profiles. The magnetic profile is a signal which is proportional to the resultant of an impedance change of the sensor, caused by the measured object (the changes are minor - of the order of 1%). Generator and bridge circuits are most commonly used as conditioning circuits for such sensors. As a result we can obtain one output signal proportional to total changes of sensor parameters (R and L). In this paper, a modified bridge circuit that allows independent measurement of the components (R and L) of the sensor's impedance, has been proposed. With that provided, it is possible to receive broader information on the object, which allows higher classification resolution. This paper provides the concept of a circuit, model testing results, processing algorithms used and the test results of a real circuit.
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Abstract

The study is aimed to quantify the effects of social noise exposure (personal music players (PMP), events with high noise exposure) and the exposure to the other environmental noise sources in the selected sample of Slovak university students. The validated ICBEN methodology was used to assess noise annoyance. The measurement of ambient noise levels was done using hand-held sound level analyzer. There were 526 university students (143 males and 383 females, average age 23±2.2) enrolled into the study so far, 192 in the exposed housing facility to road traffic noise and 326 in the control housing facility in Bratislava. The social noise exposure was quantified and followed according to the authorized methodology of the study Ohrkan. From the total sample 416 (79.4%) students reported the use of PMP in the last week for the average time of 314 minutes. There was a significant difference in PMP use between the exposed (85.34%) and the control group (76.31%) (p = 0.01). Among PMP users 28.1% exceeded the LAV (lower action value for industry = 80 dB). The results showed the importance of road traffic and the social noise as well and the need for prevention and intervention in these vulnerable groups.
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Abstract

The sound radiation from vehicles travelling on the city roads with T junction was considered. The wind effect on acoustic field was taken into account. The solution of this problem was found with the help of the integral Fourier transforms and stationary phase method as the superposition of solutions for the cases of vehicles moving along the straight roads and roads with right-angle bend. As an example, the numerical analysis of traffic noise characteristics was carried out for the T junction city road on one of streets in the town of Łodź (Poland).
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Abstract

The antilock brake system (ABS) was developed, which coordinates actions of auxiliary and working braking systems of a trolleybus. A trolleybus type 321 "Belkommunmash", equipped with the proposed ABS was tested in road conditions. The results of tests confirmed compliance of the trolleybus with requirements of the rules UN EEC No 13. Decrease in slippage of the driving wheels, improved stability, roadability and traffic safety of the trolleybus was noted.
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