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Traffic congestion spread beyond major cities and expands on national roads that connect various sites of interest. Many of these roads pass through the towns whose inhabitants must endure the negative consequences of transit traffic: increased delays and pollution levels, decreasing pedestrians safety. Thus, it is necessary to find a balance between road users’ wishes (drivers and pedestrians) in order to reduce vehicles transit time and increased pedestrians safety. The study of road traffic is a complex problem, difficult to analyze by analytical methods and therefore it is suitable for computer simulation. Using advanced simulation software, the paper investigate the influence of traffic intensity, pedestrian crossings, traffic signals timing and traffic signals coordination parameters through microsimulation of traffic on an important national road that transit a Romanian town without bypass. The proposed solutions can lead to reduced vehicles transit time, of air pollution and an increase of pedestrians safety.

According to the transport White Paper “better modal choices will result from greater integration of the modal networks: airports, ports, railway, metro and bus stations, should increasingly be linked and transformed into multimodal connection platforms for passengers.” Transport terminals are the junction points of local, regional or inter-regional transport. The main objective of a transport terminal is to serve the passengers’ demand by maintaining their safety and comfort. Intermodal terminals have emerged as a response or solution to the demands of sustainable development (reducing congestion should be the main objective), Bucharest ranks 5th in the world at congestion (according to Tomtom Traffic Index). The use of intermodality in passenger transport significantly reduces congestion in cities. Intermodal passenger terminals lead to reduced congestion but impair passenger quality parameters such as time, comfort, convenience and even travel’s cost because each mode of transport has its own pricing principles. The problem of reducing the transit time through these intermodal terminals is the key in making the public transport more attractive; the way the terminals are designed and organized leads to their intensive use or not. The paper presents a model for designing intermodal passenger terminals that encourage modal transfer. The model’s framework suppose the correlation of the transport modes timetables, placing the platforms so that the movements between them are as small as possible, tariff integration and the use of an unique ticket, etc. The model presented within the paper has been tested on a hypothetical intermodal passenger terminal that has benefitted by transport modes schedules correlation through a linear programming with integer numbers model.

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).

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.

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.

The urban transport models are used in the development of Sustainable Urban Mobility Plans. These models are designed to reproduce the actual traffic flow on transport network infrastructure and to test and evaluate the solutions that will lead to a sustainable mobility. One of these solutions is represented by the development of park and ride facilities, for users that are coming from extra urban area. The authors propose in the paper an algorithm for traffic allocation when are developed park and ride facilities. The initial data are obtained from a classic four steps model and are processed to evaluate the degree of demand of transport network when a multi-stage phased scenario is pursued. The results obtained with the proposed method are useful for local and regional decision makers to conceive a strategy to develop new park and ride facilities as well as to obtain a series of quantifiable results for transport network users.

This paper investigates the efficiency of different models in shaping the transfer function of port container terminals by coordinating the handling equipment’s activity. Differences in the productivity of the handling equipment and the limited capacity of the storage area at berth generate deadlock situation that could be handle through three correlation procedures: (i) adjusting the productivity to the minimum when the storage area is fully used; (ii) on/off control of the most efficient equipment, and (iii) limitation of the productivity of the most performing equipment. These techniques and the variations in input elements (ships arrival rate, containers number to unload/load, berth storage area) are taken into account for choosing the best strategy of port activity. A simulation model, developed with ARENA software, is created to analyse the port activity. Beyond the analytical models that deal with one ship handling process, the simulation model could take into consideration the process on a period of time, allowing studying the impact of stochastic elements on the process. The model contains the following modules: the vessels arrival, waiting in harbour, anchorage, containers unloading/loading on the vessels, temporary storage at berth, container transfer to inland storage area, and vessel departure. Computer simulations allow analysing random variable of the vessels time spent in port. The mean value should be kept at minimum and thus the best handling strategy could be identified. In addition, the sensitivity of the results according to the variation of the input elements is obtained.

Milling cutters belong to a widely used category of cutting tools. In this category, modular milling cutters are a narrow niche, less studied, and developed. Usually, they are symmetrical cutting tools. A milling cutting tool that can be reconfigured due to its modularity and still keeps its symmetry becomes more interesting and useful for machining. The paper presents such a new concept in a computer aided design (CAD) model of a cutting tool based on some novel features. The tool itself is designed as a modular complex. The way the torque is transmitted from the shaft to the elementary cutters is an original one, as they are joined together based on a profiled assembling. The profile is one formed of filleted circular sectors and segments. The reaming of the elementary cutters has two sections each of them assuming a task: transmitting the torque, and precisely centring, respectively. The cooling system, which is a component of the tool, provides the cutting area with coolant both on the front and side face of the cutting tool. Some nozzles placed around the cutting tool send jets or curtains of coolant towards the side surface of the cutter, instead of parallel, as some existing solutions do. The source of the coolant supply is the inner cooling system of the machine tool. This provides the tool with coolant having proper features: high enough flow and pressure. The output of the research is a CAD-based model of the modular milling cutter with a high performance cooling system. All of this model’s elements were designed taking into account the design for manufacturing principles, so it will be possible to easily manufacture this tool. Several variants of milling cutters obtained by reconfiguring the complex tool are presented. Even if the tool is usually a symmetric complex, it can process asymmetric parts. Symmetry is intensively used to add some advantages to the modular cutting tool: balanced forces in the cutting process, the possibility of controlling the direction of the axial cutting force, and a good machinability of the grooves used to assemble the main parts of the cutting tool.

It is well known the important role of the tools for mechanical processing in manufacturing within the present context of the rush for profitability and technical optimization for an environmentally friendly industrial production. Modularization of tools is a way to ensure their versatility being at the same time economically advantageous. In this paper, two milling cutters are adapted in order to be used also for surface hardening. The third tool described here is a newly designed modular tool that, according to needs, can be used to perform rough, finish milling or mechanical hardening.

The paper aims to identify solutions for traffic safety enhancement in an urban area where major changes in traffic flow intensity and pattern will occur. The changes of the study area pattern will be caused, on the one hand, by the development of new residential and office areas and, on the other hand, by the opening of a new road overpass linking the inner urban area with an outside area where peri- and regional traffic flow are concentrated. The assessment of the traffic systematization solutions under these new conditions is based on a simulation model developed with the AIMSUN software. The study area is located in Bucharest, around the zone of University Politehnica of Bucharest Campus. The main difficulty of the model consists in the prediction of the exogenous traffic data of the study area. The simulation model is applied for one proposed scenario considering the increase of the traffic flow intensities. A set of measures for traffic systematization is assessed and compared based on flow features (speed, frequency and time of stops, external effects limitations).

Warehousing enables the consolidation of shipments to clients by assembling full truck loads from goods stored in warehouse or distribution center. Storage can be efficiently replenished by ordering full truck loads from suppliers. In order to reduce freight storage and handling costs from distribution centers, cross-docking technique represents a logistic solution which is more and more used. Thus, the optimization of simultaneous unloading/loading operations constitutes an important issue for the distribution center owner/administrator. This paper presents a model based on genetic algorithms optimization techniques for solving the problem of unloading/loading ramps allocation. The efficiency of a cross-docking center is conditioned practically by finding an allocation and an optimal arrangement of ramps. This implies the allocation of destinations to unloading/loading ramps of distribution centers to minimize the total distance performed by the the cargo handling equipment. The case study presents a cross-docking platform with single handling equipment which is assigned to 10 unloading/loading ramps. By applying the solution of the ramp allocation generated through simulation, the total distance performed by the handling equipment is reduced which means lower handling cost for the distribution center owner/administrator.

The growth of containerization and transporting goods in containers has generated capacity and equipment allocation problems in maritime ports. Container terminals represent complex systems with dynamic interactions between the various handling, transportation and storage units, and uncertainties about future events. Maritime container terminal operates at full capacity if the arrival of vessels to berth is uniform according to its capacity and equipment operating at constant parameters. Since there are random factors both on the arrival of ships and on the operation of equipments, the paper analyzes the influence of these factors on the terminal capacity. Therefore, we proposed a generic simulation model structure for the comparative assessment of the measures of performance of maritime terminal in ideal conditions (without perturbations in the terminal operation) and in different statistical assumptions of vessels inflows to berth and number of containers to unload per vessel. Based on event driven and virtual reality technology, the handling technology simulation model is developed using ARENA simulation software. The model is set-up by combining three basic functions: transport, transfer, and stacking. The transport activity is assumed by the flows of the container vessels and trucks. Different characteristics of the arrival flows are assumed (intervals between transport units, number of containers to unload). Quay cranes provide the container transfer. The stacking areas consist in one capacity area on the quay for the quick transfer on trucks. The simulation results lead to the conclusion that it can be achieved berth high occupancy and minimization of vessels waiting time at the port if the vessels inflows follow a distribution with small variance around the ideal value.

Although >90% of total knee arthroplasties are associated with a good-to-excellent outcome, some patients have difficulty adjusting their gait to accommodate the new articulations inherent in contemporary implant designs. Paradoxical motions inclusive of anterior sliding and lateral pivot are examples of aberrant kinematics in total knee arthroplasty. A computational kinematic simulator measured the motion attained by six contemporary total knee arthroplasty designs. Results were compared with the in vivo kinematic data from healthy knees (i.e., knees with no history of surgery) in deep flexion1. Three designs employing a tibial post and a femoral cam as the motion control mechanism were evaluated, including the Legacy LPS-Flex Fixed Bearing (Zimmer, Warsaw, Indiana), the Journey (Smith and Nephew, Memphis, Tennessee), and the Vanguard PS (Biomet, Warsaw, Indiana). Three designs that did not employ a tibial post and femoral cam mechanism were also evaluated, including the MRK (Finsbury, Leatherhead, United Kingdom), the Duracon (Stryker Orthopaedics, Mahwah, New Jersey), and the Triathlon (Stryker Orthopaedics). All six designs have a fixed plateau and are currently available for clinical use in the United States. LifeMOD/KneeSIM (LifeModeler, San Clemente, California), a dynamic, validated musculoskeletal modeling system, was utilized in this study. KneeSIM provides a musculoskeletal modeling environment of the left leg of a nominal-size patient in which activities such as walking gait, lunge, stair ascent and descent, and deep-knee bend may be simulated. Activities are propelled by muscle forces and constrained by the soft tissues. Solid models of scanned geometries of the total knee arthroplasty component are arranged in the joint space to reflect a successful virtual surgery (Fig. 1). A specified activity is then simulated, and animations and plots of component and soft-tissue positions, forces, and moments are generated. Factors influencing kinematic function and stability of the knee joint, including surgical technique, component placement and …

The growth of spinal implant and orthobiologic technologies over the last several years has been increasing in tempo1 (Fig. 1) and is fast approaching the size of total hip and knee arthroplasty in annual dollar sales in the United States. During this time, a number of start-up and established medical device manufacturers have focused increasing resources on solutions for spinal problems. The role of the orthopaedic and neurosurgeon in these enterprises as inventor, owner, and user has contributed to this march of progress. This paper describes a small (

Terminals constitute the factual interface between different modes and, as a result, buffer stocks are unavoidable whenever transport flows with different discontinuities meet. This is the reason why assessing materials handling and storage capacities is an important issue in the course of attempting to increase operative planning of logistic processes in terminals. Proposed paper starts with a brief review of the compatibilities between different sorts of materials and corresponding transport modes and after, a literature overview of the studies related to ports terminals and their specialization is made. As a methodology, discrete event simulation stands as a feasible technique for assessing handling and storage capacities at the terminal, taking into consideration the multi-flows interaction and the non-uniform arrivals of vessels and inland vehicles. In this context, a simulation model, that integrates the activities of an inland water terminal and describes the essential interactions between the subsystems which influence the terminal capacity, is developed. Different scenarios are simulated for diverse sorts of materials, leading to bottlenecks identification, performance indicators such as average storage occupancy rate, average dwell or transit times estimations, and their evolution is analysed in order to improve the transfer operations in the logistic process

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.

The quality of service in transport terminals is differently perceived by engineers, economists, transport operators and sociologists. The traveler's perception is nevertheless decisive. The quality of service is well connected with the inside design of terminals, with the facilities in terminals and with the provided service standards. In order to provide a high level of service, the activities taking place in the public transport terminal and the maximum travelers flow size must be carefully analyzed and dimensioned. The purpose of modelling is to find the best route for each traveler from origin (entrance) to destination (exit) through all the intermediate service points, taking into consideration the instant network conditions. In developing the model we consider the walking, the waiting and the serving time. Using a simulation program written in ARENA we determine the waiting time. For validation, the model is used to evaluate the performance level in Bucharest Basarab station. By comparing the total walking distance for the possible routes and the utility function that describes the utility of all activities from entrance to exit we can find the optimal route.

Present paper aims to propose a set of ranking indices and related criteria, concerning mainly spatial analysis, for the inland waterway port, with special view on inland ports of Danube. Commonly, the attraction potential of a certain transport node is assessed by its spatial accessibility indices considering both spatial features of the location provided by the networks that connect into that node and its economic potential defining the level of traffic flows depending on the economic centers of its hinterland. Paper starts with a overview of the critical needs that are required for potential sites to become inland waterway ports and presents nodal functions that coexist at different levels, leading to a port hierarchy from the points of view of: capacity, connection to hinterland, traffic structure and volume. After a brief review of the key inland waterway port ranking criterion, a selection of nodal attraction measures is made. Particular considerations for the Danube inland port case follows proposed methodology concerning indices of performance for network scale and centrality. As expected, the shorter the distance from an inland port to the nearest access point the greater accessibility. Major differences in ranking, dependent on selected criterion, were registered.

Sea ports are important nodes in the supply chain, joining two high capacity transport modes: rail and maritime transport. The huge cargo flows transiting port requires high capacity construction and installation such as berths, large capacity cranes, respectively shunting yards. However, the port shunting yards specificity raises several problems such as: limited access since these are terminus stations for rail network, the in-output of large transit flows of cargo relatively to the scarcity of the departure/arrival of a ship, as well as limited land availability for implementing solutions to serve these flows. It is necessary to identify technological solutions that lead to an answer to these problems. The paper proposed a simulation model developed with ARENA computer simulation software suitable for shunting yards which serve sea ports with access to the rail network. Are investigates the principal aspects of shunting yards and adequate measures to increase their transit capacity. The operation capacity for shunting yards sub-system is assessed taking in consideration the required operating standards and the measure of performance (e.g. waiting time for freight wagons, number of railway line in station, storage area, etc.) of the railway station are computed. The conclusion and results, drawn from simulation, help transports and logistics specialists to test the proposals for improving the port management.

The concepts of reliability and vulnerability are quite important in assessing the ability of transport networks from land to provide continuity in operation tacking in consideration the relation with seaports. Transport infrastructure modernizing and extension according to land use and sustainable development requirements still represents a challenging issue among policy makers, regional/local communities and scientists. The interest for the researches reliability and vulnerability for transport networks who connect maritime ports with interior city's is generate by the natural disasters, the terrorist acts, unconventional war, etc.. Transport network modelling enable the development of mathematical models used in evaluating the reliability and vulnerability. Nodes or link disruption could have an important impact over transport network users. In our paper we investigates the Romanian road network vulnerability related to Danube crossing versus maritime ports (Constanta and Mangalia) and its mitigation by improving network topology. We use Visum software to promote a methodology to assess road transport network vulnerability versus Romanian seaports and we propose some solutions to reduce probability of road transport network to fail.

This 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.