This study focuses on both vehicle kinematic parameters (speed and acceleration) and behavior parameters (critical interval and follow-up time) of drivers at turbo-roundabouts. Empirical evaluations of such parameters can be helpful in calibrating traffic microsimulation models or assigning behavior parameters to closed-form capacity models in turbo-roundabouts (gap-acceptance capacity models) and are also related to evaluation of vehicles pollutant emissions. The research was based on traffic process observed in the first turbo-roundabout implemented in the city of Maribor in Slovenia. In 2016 a great number of traffic samples were taken with high-frame-rate video recordings [)50 frames per second (fps)]. All vehicle trajectories were obtained with the methods and algorithms typical of the digital imageprocessing technique (DIP) by filtering the discrete signal of vehicle trajectories f(t)i with wavelet analysis. The research results showed that vehicle speeds on entry lanes are rather moderate (below 25??km/h, 15 m prior to the Yield line), whereas accelerations usually have values inferior to 2??m/s2 on arm lanes and to 1.5??m/s2 on ring lanes. The critical intervals tc [distributed according to an Erlang probability distribution function (PDF)] and follow-up headways tf (distributed according to an inverse Gaussian PDF) have, on the other hand, values in ranges of tc=4.03–5.48??s and tf=2.52–2.71??s, respectively, according to the right- or left-turn lane and to the major or minor entry in question.
COBISS.SI-ID: 21323798
Consideration of environmental impacts caused by buildings with the aim of reducing environmental loads has become a high priority for the construction sector. Since the geometry and the size of buildings, two of the multiple design factors, are assumed to affect the building environmental profile, the current paper discusses the influence of the building shape on the building environmental performance. Thus, a life-cycle assessment (LCA) was conducted for five simplified reference building models with identical thermal envelope and structural properties, which were used to represent smaller residential timber building typologies such as detached (DH), semi-detached (SDH), terraced (TH), two-storey (2SH) and three-storey houses (3SH). The numerical analysis was performed with the “Baubook eco2soft” tool indicating the environmental performance of the building through the global warming potential (GWP), acidification potential (AP) and non-renewable primary energy content (PENRT) for the lifespans of 50 (50y) and 100 (100y) years. The results show a clear linear correlation between the building shape and environmental performance allowing for the use of linear interpolation and extrapolation as a simple tool to predict an approximate building environmental profile with respect to the building shape. Additionally, the findings offer suggestions towards the improvement of certain building design parameters, which presents a valuable support to building design processes.
COBISS.SI-ID: 21975830
The paper discusses the mechanical response of laminated solid wood beams with different shear connections. Experimental, analytical (gamma method) and numerical (finite element analysis) procedures were performed to estimate the effect of shear connections on the stiffness and the failure capacity of laminated solid wood beams. The 4-point bending tests were carried out on the simply supported laminated wood beams with rigid adhesive bonding, on laminated wood beams with elastomeric adhesive bonding, on screw-laminated beams (with vertical and inclined screws) and laminated beams without bonding. The results obtained from the experimental tests, and the analytical and the numerical test calculations were analysed and compared. These results show that the flexural stiffnesses of inclined screw-laminated wood beams and of laminated beams with elastomeric adhesive bonding are similar. Both stiffnesses are up to twice the amount of that of vertical screw-laminated wood beams. However, the stiffness of the laminated beams with rigid adhesive is even fifty per cent higher than that of the previously mentioned two similar stiffnesses.
COBISS.SI-ID: 21388822
In recent years, exponential growth has been detected in research efforts focused on automated construction progress monitoring. Despite various data acquisition methods and approaches, the success is limited. This paper proposes a new method, where changes are constantly perceived and as-built model continuously updated during the construction process, instead of periodical scanning of the whole building under construction. It turned out that low precision 3D scanning devices, which are closely observing active workplaces, are sufficient for correct identification of the built elements. Such scanning devices are small enough to fit onto workers’ protective helmets and on the applied machinery. In this way, workers capture all workplaces inside and outside of the building in real time and record partial point clouds, their locations, and time stamps. The partial point clouds are then registered and merged into a complete 4D as-built point cloud of a building under construction. Identification of as-designed BIM elements within the 4D as-built point cloud then results in the 4D as-built BIM. Finally, the comparison of the 4D as-built BIM and the 4D as-designed BIM enables identification of the differences between both models and thus the deviations from the time schedule. The differences are reported in virtual real-time, which enables more efficient project management.
COBISS.SI-ID: 21511190
Real-time information system about bus arrival and departure times at bus stops is one of the key elements of high-quality public transport. To provide accurate prediction of bus arrival at the bus stop the information of current position of the bus and bus travel time to the target stop are required. This paper investigates the bus velocity during different time periods and the impact of the bus network data model on the real-time prediction of arrival times at bus stops. The proposed model classifies bus travel times into time periods with respect to the historical data and the data model of the bus network. Discussion of four types of data model is presented, such as: a data model defined by bus stops and junctions of the roads, a data model defined only by bus stops, a data model which addresses the individual parts of the network in relation to the potential barriers that affect the travel speed of buses, and a data model with fixed-length links of the bus network. The analysis is performed in two different environments, the city of Ljubljana and the city of Maribor. The travel times are classified according to the average travel speed into four time periods: morning, afternoon, weekend and off-peak periods. Simulations showed that both the data model of the bus network and classifying runs into time periods affect the accuracy of predictions of bus arrival times at bus stops.
COBISS.SI-ID: 21460502