Articles
Vol. 28 No. 5 (2016)
Published on 26.10.2016
Ming Zhang, Shuo Wang, Hui Yu
2016 (Vol 28), Issue 5
This study proposes a low-altitude wind prediction model for correcting the flight path plans of low-altitude aircraft. To solve large errors in numerical weather prediction (NWP) data and the inapplicability of high-altitude meteorological data to low altitude conditions, the model fuses the low-altitude lattice prediction data and the observation data of a specified ground international exchange station through the unscented Kalman filter (UKF)-based NWP interpretation technology to acquire the predicted low-altitude wind data. Subsequently, the model corrects the arrival times at the route points by combining the performance parameters of the aircraft according to the principle of velocity vector composition. Simulation experiment shows that the RMSEs of wind speed and direction acquired with the UKF prediction method are reduced by 12.88% and 17.50%, respectively, compared with the values obtained with the traditional Kalman filter prediction method. The proposed prediction model thus improves the accuracy of flight path planning in terms of time and space.
Aleksandar Sušić, Davor Sumpor
2016 (Vol 28), Issue 5
Mia Suhanek, Ivan Đurek
2016 (Vol 28), Issue 5
Four different acoustic environments with different loudness levels and spectral distributions were recorded and reproduced to two groups of listeners - control group and experimental group. The questionnaire used in this research relies on the semantic differential method implemented by defining adjective pairs of opposite meaning where each pair describes a sound characteristic for a particular acoustic environment. In analyzing the results, psychological research methodology was used in order to determine statistically significant bipolar adjectives that can appropriately evaluate some given acoustic environment and thus serve as a starting point for a questionnaire and methodology standardization in soundscape research.
Shumin Feng, Xianghao Shen, Baoyu Hu
2016 (Vol 28), Issue 5
As the two most important modes in public transportation, the coordinated development of bus and metro networks significantly influences the efficiency of public transportation. However, two parallel bus and metro lines belonging to different operators may lead to supply competition and consequently yield over-supply. Taking two parallel bus and metro lines in Harbin city, China as a case study, this paper, drawing on game theory, establishes a utility model based on the two lines’ frequencies, and reveals and explains the fundamental reason for the over-supply problem using a Nash equilibrium. In an attempt to resolve this issue, the study proposes a new operation mode: integrating frequencies of the two modes to obtain larger total profits then reallocating the total profits to the two modes. The case study shows that this new operation mode can effectively solve the over-supply problem while satisfying both operators of the two modes, and hence having practical value.
Adam Stančić, Ivan Grgurević, Zvonko Kavran
2016 (Vol 28), Issue 5
Integration of the collected information on the road within the image recorded by the surveillance system forms a unified source of transport-relevant data about the supervised situation. The basic assumption is that the procedure of integration changes the image to the extent that is invisible to the human eye, and the integrated data keep identical content. This assumption has been proven by studying the statistical properties of the image and integrated data using mathematical model modelled in the programming language Python using the combinations of the functions of additional libraries (OpenCV, NumPy, SciPy and Matplotlib). The model has been used to compare the input methods of meta-data and methods of steganographic integration by correcting the coefficients of Discrete Cosine Transform JPEG compressed image. For the procedures of steganographic data processing the steganographic algorithm F5 was used. The review paper analyses the advantages and drawbacks of the integration methods and present the examples of situations in traffic in which the formed unified sources of transport-relevant information could be used.
Milan Vujanić, Milan Savićević, Boris Antić, Dalibor Pešić
2016 (Vol 28), Issue 5
Intersections present a big safety problem in traffic since there has been an increased risk of crashes because of conflicts in the flows intersecting. A great number of studies done in the world show that roundabouts are safer than conventional intersections since it has been recorded that after the conversion to roundabouts the number of crashes has been decreasing. The research on applying Empirical Bayes (EB) method has been conducted by using 15 two-lane intersections in the city of Niš (Serbia), which have been converted into large compact two-lane roundabouts during the period of 2005-2013. The results show that the conversion of conventional intersections into roundabouts has positive effect on reducing the number of crashes. For all intersections, the reduction of crashes is estimated at around 76% for all crashes, i.e. 80% for the crashes with injuries. For different groups of intersections the effects are determined separately.
Duo Li, Prakash Ranjitkar, Yifei Zhao
2016 (Vol 28), Issue 5
Ramp metering (RM) has been widely applied due to its effectiveness in improving motorway traffic conditions by limiting inflow from on-ramps. A great deal of experimental and simulation-based studies have proven system-wide benefits of motorways from RM. Benefits attributed to RM in the literature include reducing travel times, increasing motorway throughputs and decreasing fuel consumption and emissions. However, RM benefits might be costing more some motorway users, e.g. some on-ramp users might be experiencing longer delay than others, which leads to an unfair allocation of RM benefits. This paper presents a coordinated ramp metering strategy, which is aimed at reducing the inequity among motorway users using different on-ramps and investigates trade-offs between efficiency and equity for the proposed strategy. Total travel time is used to measure the efficiency while Gini coefficient is used to measure equity. A combined index is proposed incorporating the two measures to serve as an objective function to solve the bi-objective control design problem. The performance of the proposed strategy is verified by comparing it to a well-established coordinated ramp metering strategy HERO using micro-simulation
software AIMSUN. Simulation results revealed that the equity of the motorway system can be improved significantly by using the proposed strategy without compromising much on the efficiency of the system.
Tomislav Rožić, Kristijan Rogić, Ivona Bajor
2016 (Vol 28), Issue 5
Inland terminals are becoming an increasingly important factor for disburdening port storage capacities and the expansion of the port gravitational areas. The above defines inland terminals as facilities with prolonged activities of seaports, or an integral part of the port. Due to increased interest in the development of inland terminals, the literature in the field of inland terminals since the beginning of its research (1980) to the latest research in 2015 has been analysed
and revised. The review will summarize the literature related to development, classification, technological processes and location of inland terminals. In the end, the paper identifies a new proposition for further research based on the current trends and developments in inland terminals as an important factor of intermodal transport.
Jasna Golubić, Zoran Vogrin, Eduard Missoni
2016 (Vol 28), Issue 5
The paper gives an overview of the specific features of anthropometric characteristics of humans – pedestrians in case of car accidents involving pedestrians and cars. Here, special attention has been paid to the configuration of the human body while moving, which is in turn related to the initial conditions of a collision. Special part of biomechanics in humans refers to their moving, where human’s walk has a specific posture as a mechanical phenomenon. Based on the carried out analysis the need has been observed for a classification of anthropologic variables by means of which the dynamic inertia moments of a walking human can be calculated, as well as the human, who hit by a car in a traffic accident flies along a production curvilinear path. With the development of ergonomics, and the accompanying increased application of anthropometry, the static anthropometry was abandoned, since the humans are considered highly variable in their dimensions, which is extremely important
for the dynamic analysis of the human body posture in the collision process.
Jurica Ivošević, Tino Bucak, Davor Sumpor
2016 (Vol 28), Issue 5
Previous studies have shown that the impact of interior aircraft noise on pilot performance was not unambiguous, neither there was any unanimous methodology used for measuring it. Furthermore, the cumulative character of noise was never taken into account. This research proposes a methodology that aims to determine the impact of accumulated general aviation aircraft interior noise on pilot performance in laboratory conditions. The assessment of the aircraft interior noise influence on Temporary Threshold Shift is integrated as well, enabling extended research of all aspects of the physiological noise impact on pilots. Methodology defines measurable noise and pilot performance parameters in general aviation, equipment requirements, necessary laboratory conditions and subject selection criteria. The analysis of the deviation from the specified flight parameters along with Temporary Threshold Shift values at different accumulated noise doses is carried out. Data is analyzed using descriptive statistics, visualization methods and linear mixed effects models with False Discovery Rate as the method for correction for multiple testing which allows the determination of the potential population effect.
Yagang Zhang, Dingli Qi, Wei Jiang, Shuang Lei
2016 (Vol 28), Issue 5
Electric vehicle as the main development direction of the future automotive industry, has gained attention worldwide. The rationality of the planning and construction of the power station, as the foundation of energy supply, is an important premise for the development of electric vehicles. In full consideration of the electric demand and electricity consumption, this paper proposes a new construction mode in which charging station and centralized charging station are appropriately combined and presents a location optimization model. Not only can this model be applied to determine the appropriate location for the power station, but it can use the queuing theory to determine the optimal number of power equipment, with which we can achieve the minimum costs. Finally, taking a certain city as an example, the optimum plan for power station is calculated by using this model, which provides an important reference for the study of electric vehicle infrastructure planning.
Wenliang Zhou, Xia Yang, Lianbo Deng, Jin Qin
2016 (Vol 28), Issue 5
Urban rail crew scheduling problem is to allocate train services to crews based on a given train timetable while satisfying all the operational and contractual requirements. In this paper, we present a new mathematical programming model with the aim of minimizing both the related costs of crew duty and the variance of duty time spreads. In addition to iincorporating the commonly encountered crew scheduling constraints, it also takes into consideration the constraint of arranging crews having a meal in the specific meal period of one day rather than after a minimum continual service time. The proposed model is solved by an ant colony algorithm which is built based on the construction of ant travel network and the design of ant travel path choosing strategy. The performances of the model and the algorithm are evaluated by conducting case study on Changsha urban rail. The results indicate that the proposed method can obtain a satisfactory crew schedule for urban rails with a relatively small computational time.
