Using Intersection Conflict Index in Urban Traffic Risk Evaluation

AbstractThis paper presents part of the research on traffic risk estimation for Bucharest City area. The aim of our research is to develop complex models as tools of urban traffic risk assessment in planning phase. In this way, several urban planning alternatives could be analysed and evaluate before important transport infrastructure investment are made. The first part of the paper analyses the state of road accidents recorded in Bucharest. The second part of the paper demonstrates how the intersection conflict index can be used in traffic micro-simulation models to assess measures of traffic risk reducing

Including negative externalities during transport infrastructure construction in assessment of investment projects

The paper presents a method for optimizing the financing option for transport infrastructure project. The execution time for large project is substantial and the social costs generated during the construction phase are insufficient included in the assessment models. These are the main reasons for starting the research to extend the project evaluation methods with procedures that consider also social costs during the implementation of the project, besides the social costs after work completion. The proposed method aims to enhance the solution given by the current applied methods for investment assessment. Starting from the results of the present procedures of transport investment assessment, two approaches are presented. The first one assumes that the work starts at the reference year and different construction schemes can be applied. The optimal time of project implementation is determined considering the social costs during construction and after project implementation. In the second approach, the purpose is to determine the moments of the starting and the completion of the works for minimum of the losses caused by the social costs before and during the project implementation. The paper emphasizes that social cost during transport infrastructure work must be considered in investment timing. In this regard, supplementary procedures can be added to the current method used for ranking of the transport infrastructure investments. For an investment measure identified as opportune, the proposed method aim to minimize the total social cost. Document type: Articl

Dynamic study of milling low depth channels

This paper presents a study of dynamic aspects of the milling cutters used in particular case of low depth channels. A new calculation method was developed, taking into account the high variations of cutting forces during milling small depth channels with peripheral cutting tools. A new formula was established for the minimal value of channel depth that allows cutting process to be performed in conditions of dynamic stability

Dynamic study of milling low depth channels

This paper presents a study of dynamic aspects of the milling cutters used in particular case of low depth channels. A new calculation method was developed, taking into account the high variations of cutting forces during milling small depth channels with peripheral cutting tools. A new formula was established for the minimal value of channel depth that allows cutting process to be performed in conditions of dynamic stability

Modular milling cutter with inner-cooling network

The big sized milling cutters are expensive tools and are not appropriate for small batches production. Making these tools more versatile, able to fit to different kinds of processes and shapes of the parts to be machined is a must. As well, cooling the cutting area is very important. The existing end-mill cutters are designed to feed internally with coolant only the teeth on the front side. The paper presents a concept of a modular tool, made of elementary disk cutters, able to be reconfigured to get different shapes and sizes. The main element of novelty the paper claims is the inner cooling system of the complex tool. The special design of the elementary milling cutters and of the shaft they are mounted on make the tool able to lead jets of coolant to every insert, no matter where they are placed, on the cylindrical or on the front side of the milling cutter. A network of channels drilled in the shaft and in the body of elementary milling cutters make this possible. The capability to splash with coolant under high pressure all the cutting edges do not depend on the number of teeth of the tool. Being delivered from inside the cutting tool, the coolant splashes directly on the contact surface between the inserts and workpiece, which makes cooling more efficient

Assessing the transit capacity of port shunting yards through discrete simulation

The port shunting yards are developed inside the area of the ports. The main activities are to receive the freight trains from the hinterland, to shunt the freight wagons according to their final destinations from the area of the port, to receive the wagons from maritime terminals, to accumulate wagons according to their destination, and to depart the freight train to the hinterland. So, it is important for port administration to have good methods to evaluate the transit capacity of port shunting yards. A feasible method is to use the discrete simulation model. In our paper, we develop one of this taking into consideration the input flow characteristics of freight trains from land network, the input flow characteristics of freight wagons from maritime terminals, the number of tracks in a port railway station, the technology used for separation of freight wagons on destinations (inside the port or from hinterland), and the duration of technological processes. From the results, we extract the values of trains and wagon sets that transit through the main areas of the railway station (Receiving Tracks, Hump(s) and Departure Tracks)

Including negative externalities during transport infrastructure construction in assessment of investment projects

Abstract The paper presents a method for optimizing the financing option for transport infrastructure project. The execution time for large project is substantial and the social costs generated during the construction phase are insufficient included in the assessment models. These are the main reasons for starting the research to extend the project evaluation methods with procedures that consider also social costs during the implementation of the project, besides the social costs after work completion. The proposed method aims to enhance the solution given by the current applied methods for investment assessment. Starting from the results of the present procedures of transport investment assessment, two approaches are presented. The first one assumes that the work starts at the reference year and different construction schemes can be applied. The optimal time of project implementation is determined considering the social costs during construction and after project implementation. In the second approach, the purpose is to determine the moments of the starting and the completion of the works for minimum of the losses caused by the social costs before and during the project implementation. The paper emphasizes that social cost during transport infrastructure work must be considered in investment timing. In this regard, supplementary procedures can be added to the current method used for ranking of the transport infrastructure investments. For an investment measure identified as opportune, the proposed method aim to minimize the total social cost