Complex Transport System Research Articles

Modeling heterogeneous traffic flow: A pragmatic approach

Modeling dynamics of heterogeneous traffic flow is central to the control and operations of today’s increasingly complex transportation systems. We develop a macroscopic heterogeneous traffic flow model. This model considers interplay of multiple vehicle classes, each of which is assumed to possess homogeneous car-following behavior and vehicle attributes. We propose the concepts of road capacity split and perceived equivalent density for each class to model both lateral and longitudinal cross-class interactions across neighboring cells. Rather than leveraging hydrodynamic analogies, it establishes pragmatic cross-class interaction rules aspired by capacity allocation and approximate inter-cell fluxes. This model generalizes the classical Cell Transmission Model (CTM) to three types of traffic regimes in general, i.e. free flow, semi-congestion, and full congestion regimes. This model replicates prominent empirical characteristics exhibited by mixed vehicular flow, including formation and spatio-temporal propagation of shockwaves, vehicle overtaking, as well as oscillatory waves. Those features are validated against numerical experiments and the NGSIM I-80 data. Realistic class-specific travel times can be computed from this model efficiently, which demonstrates the feasibility of applying this multi-class model to large-scale real-world networks.

Controllable Molecular Motors Engineered from Myosin and RNA

Engineering biomolecular motors can provide direct tests of structure-function relationships and customized components for controlling molecular transport in artificial systems or in living cells. In previous work, synthetic nucleic acid motors have been designed from first principles and engineered for versatile programmable control; in a complementary approach, natural protein motors have been modified to combine some control and tunability with favorable evolved properties such as speed, processivity, and biological compatibility. Nucleoprotein motors such as the ribosome illustrate the potential for tightly integrating protein and nucleic acid components to enable sophisticated functionality. However, this potential has only begun to be explored in pioneering work harnessing DNA scaffolds to dictate the spacing, number, and composition of tethered protein motors. Here, we describe myosin motors that incorporate RNA lever arms, forming hybrid assemblies in which conformational changes in the protein motor domain are amplified and redirected by nucleic acid structures. The RNA lever arm geometry determines the speed and direction of motor transport, and can be dynamically controlled using programmed transitions in lever arm structure. We have characterized the hybrid motors using in vitro assays of propelled actin filaments, single-molecule tracking of tetrameric processive walkers, cryoelectron microscopy, and MOHCA-seq structural probing. Our results confirm the operation of motors designed to reversibly change direction in response to oligonucleotide signals that drive strand-displacement reactions. This work enables future applications in which complex transport systems are programmed using sequence-addressable control of speed and direction in heterogeneous motor collections; in principle, the signaling inputs can originate from transcriptional circuits or DNA computations. Similar combinations of nucleic acid structures and diverse protein motors may provide a general strategy for controlling dynamic behavior, with collective motor properties further determined by precise arrangement and orientation on larger nucleic acid scaffolds.

A novel investigation of a micropolar fluid characterized by nonlinear constitutive diffusion model in boundary layer flow and heat transfer.

The rheological and heat-conduction constitutive models of micropolar fluids (MFs), which are important non-Newtonian fluids, have been, until now, characterized by simple linear expressions, and as a consequence, the non-Newtonian performance of such fluids could not be effectively captured. Here, we establish the novel nonlinear constitutive models of a micropolar fluid and apply them to boundary layer flow and heat transfer problems. The nonlinear power law function of angular velocity is represented in the new models by employing generalized "n-diffusion theory," which has successfully described the characteristics of non-Newtonian fluids, such as shear-thinning and shear-thickening fluids. These novel models may offer a new approach to the theoretical understanding of shear-thinning behavior and anomalous heat transfer caused by the collective micro-rotation effects in a MF with shear flow according to recent experiments. The nonlinear similarity equations with a power law form are derived and the approximate analytical solutions are obtained by the homotopy analysis method, which is in good agreement with the numerical solutions. The results indicate that non-Newtonian behaviors involving a MF depend substantially on the power exponent n and the modified material parameter [Formula: see text] introduced by us. Furthermore, the relations of the engineering interest parameters, including local boundary layer thickness, local skin friction, and Nusselt number are found to be fitted by a quadratic polynomial to n with high precision, which enables the extraction of the rapid predictions from a complex nonlinear boundary-layer transport system.

Efficiency increase of complex production and transport systems management

This article deals with the problem of the reduced efficiency of management in complex production - transport systems due to the lack of co-ordination in the operation of industrial enterprises and transport carrying out their maintenance. The existing transport service schedules for auxiliary departments do not take into account possible changes in operating conditions, the probability of malfunctions and the amount of reserves, which leads to an increase in general production costs. To solve this problem, we propose to use the interval regulation of production and transport processes in all departments of the complex production and transport systems. Also, such regulation involves the determination of traffic service priority. This will allow passing on from the regulated control of production and transport processes to the situational one, adapted to specific conditions, and reducing losses from untimely transport servicing, which will lead to a stores reduction and efficiency increase of the enterprise circulating facilities use. Testing the effectiveness of interval regulation was performed on the system and dynamics simulation model of liquid iron transportation in the oxygen converter shop of the metallurgical enterprise. It was established that the use of interval regulation processes in iron production and its transportation will allow decreasing non-productive downtime by 21% and the amount of the liquid iron in anticipation of recasting in the oxygen converter shop – by 33%. Economical effect of reducing the liquid iron downtime during transportation to the oxygen converter shop will be about 30 million rubles per year.

A Survey on Infrastructure-Based Vehicular Networks

The infrastructure of vehicular networks plays a major role in realizing the full potential of vehicular communications. More and more vehicles are connected to the Internet and to each other, driving new technological transformations in a multidisciplinary way. Researchers in automotive/telecom industries and academia are joining their effort to provide their visions and solutions to increasingly complex transportation systems, also envisioning a myriad of applications to improve the driving experience and the mobility. These trends pose significant challenges to the communication systems: low latency, higher throughput, and increased reliability have to be granted by the wireless access technologies and by a suitable (possibly dedicated) infrastructure. This paper presents an in-depth survey of more than ten years of research on infrastructures, wireless access technologies and techniques, and deployment that make vehicular connectivity available. In addition, we identify the limitations of present technologies and infrastructures and the challenges associated with such infrastructure-based vehicular communications, also highlighting potential solutions.

Idea of Identification of Copper Ore with the Use of Process Analyser Technology Sensors

The Polish resources of the copper ore exploited by the KGHM S.A. underground mines are considered as one of the most complex in the world and - consequently - the most difficult to be processed. The ore consists of three lithology forms: dolomites, shales and sandstones but in different proportions which has a significant impact on the effectiveness of the grinding and flotation processes. The lithological composition of the ore is generally recognised in-situ but after being mined it is blended on its long way from various mining fields to the processing plant by the complex transportation system consisting of belt conveyors with numerous switching points, ore bunkers and shafts. Identification of the lithological composition of the ore being supplied to the processing plant should improve the adjustments of the ore processing machinery equipment aiming to decrease the specific processing (mainly grinding) energy consumption as well as increase the metal recovery.The novel idea of Process Analyser Technology (PAT) sensors - information carrying pellets, dropped into the transported or processed bulk material which can be read directly when needed - is investigated for various applications within the DISIRE project (a part of the SPIRE initiative, acting under the Horizon2020 framework program) and here is adopted for implementing the annotation the transported copper ore for the needs of ore processing plants control. The identification of the lithological composition of ore blended on its way to the processing plant can be achieved by an information system consisting of pellets that keep the information about the original location of the portions of conveyed ore, the digital, geological database keeping the data of in-situ lithology and the simulation models of the transportation system, necessary to evaluate the composition of the blended ore. The assumptions of the proposed solution and the plan of necessary in-situ tests (with the special respect to harsh environment of

Construction of a conceptual model of transport system for a coal mining region

The methodological approaches to creation of a conceptual model of complex transport system for coal-mining region are substantiated. In the structure of the system base model the ensemble of local interconnected subsystems is distinguished. The local structure of the traffic management system of cargo transportation company is developed, the factors and indicators affecting the efficiency of cargo management are highlighted.

Cost efficiency in Swedish public transport

Over the last couple of years, costs in Swedish public transport have increased substantially, and there is little knowledge in what affects cost efficiency. This study aims at determining how different contractual and environmental factors affect cost efficiency, and whether cost efficiency differs between Public Transport Authorities (PTA). A stochastic frontier analysis is conducted using contract-level data for the 21 PTAs and year 2013. The main findings are that cost efficiency is lower if a contract is operating in areas with high population density, or if the traffic is supplied by a publicly owned operator without using competitive tendering. Furthermore, no major differences in cost efficiency are found across PTAs, with the exception of the counties of Stockholm and Skåne, both counties with high population density, and the county of Västmanland, where all public transport is provided without competitive tendering. The finding of lower cost efficiency in high-density areas calls for further investigation into why this is. Potential explanations are the need for higher peak capacity, or more complex transportation systems. Finally, usage of direct-awarding of public transport should be clearly motivated, as this affects cost efficiency negatively.

Designing for bus stop experience: An emotion-driven project

The present paper investigates the process of developing an experimental design project for users of urban public transport in a large southern Brazilian city, Porto Alegre. This research, however, refers to a very specific aspect within this complex transportation system: bus stops. Its main objective is to evaluate the contribution of design process based on emotion-driven approaches on bus stop concept development. It presents three separate methodological steps and their respective results: (step 1) a preliminary in loco observation followed by a first design workshop; (step 2) an in-loco analysis of users’ emotional experiences when using public transport; and (step 3) the application of this information in design workshops. The first step provided a general view of the phenomenon and fed the design process with inputs from real-world situations. The second step was based on Appraisal Theory (Desmet, 2008) and helped the researchers to understand that the most important emotions to work on would be anxiety and irritation, as well as the concerns that would trigger then on users. The third step, a three-day design workshop, was developed with the participation of 23 designers, divided into four groups. Three bus stop concepts, inspired by the experience-design analysis, were developed and are presented in this paper. The main results showed that all the designed solutions were able to offer alternatives to prevent unpleasant emotions, namely anxiety and irritation, based on a user-centered approach. The research also reinforced the view that, although it is not possible to design emotions, it is possible to design tangible conditions where emotions can be avoided or reinforced. Keywords: urban mobility, bus stops, design for experience, emotion.

Fast and Accurate Mining the Community Structure: Integrating Center Locating and Membership Optimization

Mining communities or clusters in networks is valuable in analyzing, designing, and optimizing many natural and engineering complex systems, e.g., protein networks, power grid, and transportation systems. Most of the existing techniques view the community mining problem as an optimization problem based on a given quality function(e.g., modularity), however none of them are grounded with a systematic theory to identify the central nodes in the network. Moreover, how to reconcile the mining efficiency and the community quality still remains an open problem. In this paper, we attempt to address the above challenges by introducing a novel algorithm. First, a kernel function with a tunable influence factor is proposed to measure the leadership of each node, those nodes with highest local leadership can be viewed as the candidate central nodes. Then, we use a discrete-time dynamical system to describe the dynamical assignment of community membership; and formulate the serval conditions to guarantee the convergence of each node's dynamic trajectory, by which the hierarchical community structure of the network can be revealed. The proposed dynamical system is independent of the quality function used, so could also be applied in other community mining models. Our algorithm is highly efficient: the computational complexity analysis shows that the execution time is nearly linearly dependent on the number of nodes in sparse networks. We finally give demonstrative applications of the algorithm to a set of synthetic benchmark networks and also real-world networks to verify the algorithmic performance.

A simulation study of the impact of the public-private partnership strategy on the performance of transport infrastructure.

The choice of investment strategy has a great impact on the performance of transport infrastructure. Positive projects such as the “Subway plus Property” model in Hong Kong have created sustainable financial profits for the public transport projects. Owing to a series of public debt and other constraints, public–private partnership (PPP) was introduced as an innovative investment model to address this issue and help develop transport infrastructure. Yet, few studies provide a deeper understanding of relationships between PPP strategy and the performance of such transport projects (particularly the whole transport system). This paper defines the research scope as a regional network of freeway. With a popular PPP model, travel demand prediction method, and relevant parameters as input, agents in a simulation framework can simulate the choice of PPP freeway over time. The simulation framework can be used to analyze the relationship between the PPP strategy and performance of the regional freeway network. This study uses the Freeway Network of Yangtze River Delta (FN-YRD) in China as the context. The results demonstrate the value of using simulation models of complex transportation systems to help decision makers choose the right PPP projects. Such a tool is viewed as particularly important given the ongoing transformation of functions of the Chinese transportation sector, including franchise rights of transport projects, and freeway charging mechanism.

Some Aspects of Mega-Floating Airport Design and Production

Mega-Floating Airports (MFA) are unique and complex offshore transport system components that emerged as a consequence of tremendous land price increase in the vicinity of very large coastal cities. An overview of MFAs design and production aspects is presented within this paper including design concept, model tests and full scale measurement, air transport analysis, infrastructure, main particulars and structure, wave breaker, hydroelastic analysis due to wave load and airplane moving mass, mooring analysis, production technology and environmental aspects. MFA dynamic response due to airplane load is emphasized as the most challenging problem. Theoretical outline as well as a realistic illustrative numerical example are presented.

A-RIDE를 통한 초고층 업무시설의 수직동선계획 검증에 관한 연구

The purpose of this research is to verify the validity of A-RIDE, a developed vertical transportation planning program. A-RIDE is a web-based software program that can present reasonable vertical transportation plan alternatives for high-rise buildings, based on basic building information at an early design phase. This research focused on high-rise office buildings which have a complex vertical transportation system due to heavy traffic. For verification, an object building have been selected and vertical transportation has been planned using A-RIDE. The presented vertical transportation plan and the actual plan have been compared and analyzed. Results of A-RIDE were similar to the actual plan which verifies the significance of this program as a vertical transportation planning tool for the early design phase. Through further research, this program has the potential to become a powerful design tool for architects planning high-rise buildings.

Importance of organellar proteins, protein translocation and vesicle transport routes for pollen development and function.

Protein translocation. Cellular homeostasis strongly depends on proper distribution of proteins within cells and insertion of membrane proteins into the destined membranes. The latter is mediated by organellar protein translocation and the complex vesicle transport system. Considering the importance of protein transport machineries in general it is foreseen that these processes are essential for pollen function and development. However, the information available in this context is very scarce because of the current focus on deciphering the fundamental principles of protein transport at the molecular level. Here we review the significance of protein transport machineries for pollen development on the basis of pollen-specific organellar proteins as well as of genetic studies utilizing mutants of known organellar proteins. In many cases these mutants exhibit morphological alterations highlighting the requirement of efficient protein transport and translocation in pollen. Furthermore, expression patterns of genes coding for translocon subunits and vesicle transport factors in Arabidopsis thaliana are summarized. We conclude that with the exception of the translocation systems in plastids-the composition and significance of the individual transport systems are equally important in pollen as in other cell types. Apparently for plastids only a minimal translocon, composed of only few subunits, exists in the envelope membranes during maturation of pollen. However, only one of the various transport systems known from thylakoids seems to be required for the function of the "simple thylakoid system" existing in pollen plastids. In turn, the vesicle transport system is as complex as seen for other cell types as it is essential, e.g., for pollen tube formation.

The Impact of Short Term Traffic Forecasting on the Effectiveness of Vehicles Routes Planning in Urban Areas

An impossibility to foresee in advance the accurate traffic parameters in face of dynamism phenomena in complex transportation system is a one of the major source of uncertainty. The paper presents an approach to robust optimization of logistics vehicle routes in urban areas on the basis of estimated short-term traffic time forecasts in a selected area of the urban road network. The forecast values of optimization parameters have been determined using the spectral analysis model, taking into account the forecast uncertainty degree. The robust counterparts approach of uncertain bi-criteria shortest path problem formulation is used to determining the robust routes for logistics vehicles in the urban network. The uncertainty set is created on the basis of forecast travel times in chosen sections, estimated by means of spectral analysis. The advantages and the characteristics are exemplified in the actual Krakow road network. The obtained data have been compared with classic approach wherein it is assumed that the optimization parameters are certain and accurate. The results obtained in the simulation example indicate that use of forecasting techniques with robust optimization models has a positive impact on the quality of final solutions.

Intracellular Trafficking Network of Protein Nanocapsules: Endocytosis, Exocytosis and Autophagy.

The inner membrane vesicle system is a complex transport system that includes endocytosis, exocytosis and autophagy. However, the details of the intracellular trafficking pathway of nanoparticles in cells have been poorly investigated. Here, we investigate in detail the intracellular trafficking pathway of protein nanocapsules using more than 30 Rab proteins as markers of multiple trafficking vesicles in endocytosis, exocytosis and autophagy. We observed that FITC-labeled protein nanoparticles were internalized by the cells mainly through Arf6-dependent endocytosis and Rab34-mediated micropinocytosis. In addition to this classic pathway: early endosome (EEs)/late endosome (LEs) to lysosome, we identified two novel transport pathways: micropinocytosis (Rab34 positive)-LEs (Rab7 positive)-lysosome pathway and EEs-liposome (Rab18 positive)-lysosome pathway. Moreover, the cells use slow endocytosis recycling pathway (Rab11 and Rab35 positive vesicles) and GLUT4 exocytosis vesicles (Rab8 and Rab10 positive) transport the protein nanocapsules out of the cells. In addition, protein nanoparticles are observed in autophagosomes, which receive protein nanocapsules through multiple endocytosis vesicles. Using autophagy inhibitor to block these transport pathways could prevent the degradation of nanoparticles through lysosomes. Using Rab proteins as vesicle markers to investigation the detail intracellular trafficking of the protein nanocapsules, will provide new targets to interfere the cellular behaver of the nanoparticles, and improve the therapeutic effect of nanomedicine.

Agent-Based Modeling and Simulation of Coordination by Airline Operations Control

This paper implements and compares four coordination policies through agent-based modeling and simulation (ABMS), motivated by the need to understand and further optimize coordination processes in the highly complex socio-technical air transportation system. Three policies are based on established practices, whereas a fourth is based on the joint activity coordination theory from the psychology research domain. For each of these four policies, the relation with the literature on coordination is identified. The specific application of the four policies concerns airline operations control (AOC), which core’s functionality is one of coordination and taking corrective actions in response to a large variety of airline operational disruptions. In order to evaluate the four policies, an agent-based model of the AOC and crew processes has been developed. Subsequently, this agent-based model is used to assess the effects of the four AOC policies on a challenging airline disruption scenario. For the specific scenario considered, the joint-activity coordination-based AOC policy outperforms the other three policies. More importantly, the simulation results provide novel insight in the operational effects of each of the four AOC policies, which demonstrate that the ABMS allows to analyze the effectiveness of different coordination policies in the complex socio-technical air transportation system.

Intelligent Bus Stand Fees Management System Using RFID

All over the world cities, authorities and companies are facing great challenges in designing transport systems for the future. The demand for transportation, both regarding people and freight, will continue to increase and to increase efficiency, mobility and customer satisfaction while reduce environmental impact, traffic congestion and the number of accidents will always be of greatest concern. The performance of the transport systems is of crucial importance for individual mobility, business opportunities and for the welfare level and economic growth of a nation. Intelligent transport systems (ITS) are systems that integrate technology developments in the fields of telecommunication and information technology with the physical infrastructure and vehicles, with the aim to satisfy goals in terms of efficiency, mobility, safety and environmental impact. There is an increasing demand for transportation engineers with knowledge about the relevant communication technology in the field and about the planning tools for designing, analyzing and evaluating the performance of the complex transport systems. This proposed system studies the Intelligent Bus Stand Fees Management System is based on radio frequency identification (RFID) system. The manual system of fee management poses lots of problems including wastage of time and uncontrolled traffic. This proposed system proposes to reduce the problem by designing automatic toll collection using RFID and bus card. The proposed system will be running by accessing the code of bus, contained in the card, and then comparing it with the database. The interface developer needs to have details of the vehicle like bus make and model, bus number, license of the driver and owner along with contact details of the owner. This information needs to be correctly uploaded so that the interface works correctly. Developer needs to choose port and code to make connection with RFID reader. The user just needs to swap his card on the reader and the code from the card will be compared with the database in access. If the code matches with the database, the user information gets displayed on the computer of the operator. If the code does not match with the interface, the operator may check for the details and in case of new user, not already registered, may register his vehicle. This system aims to make a more efficient, easy and hassle free bus fee management system.

Room temperature Coulomb blockade effects in Au nanocluster/pentacene single electron transistors

Single-electron transistors incorporating single ∼1 nm gold nanocluster (AuNCs) and pentacene as a complex charge transport system have been used to study the quantum Coulomb blockade and its single electron tunnelling behaviour at room temperature (RT) (300 K). Monodisperse ultra-small (0.86 ± 0.30 nm) AuNCs were deposited by the tilted-target sputtering technique into 12 nm nanogaps fabricated by high-resolution e-beam lithography. Tunnelling resistance was modulated to ∼109 Ω by addition of a pentacene layer, allowing clear observation of quantum staircases and Coulomb oscillations with on/off current modulation ratio of ∼100 in RT current–voltage measurements. The electron addition energy and average quantized energy level spacing were found to be 282 and 80.4 meV, respectively, which are significantly larger than the thermal energy at 300 K (25.9 meV).

Predicting traffic volumes and estimating the effects of shocks in massive transportation systems

Public transportation systems are an essential component of major cities. The widespread use of smart cards for automated fare collection in these systems offers a unique opportunity to understand passenger behavior at a massive scale. In this study, we use network-wide data obtained from smart cards in the London transport system to predict future traffic volumes, and to estimate the effects of disruptions due to unplanned closures of stations or lines. Disruptions, or shocks, force passengers to make different decisions concerning which stations to enter or exit. We describe how these changes in passenger behavior lead to possible overcrowding and model how stations will be affected by given disruptions. This information can then be used to mitigate the effects of these shocks because transport authorities may prepare in advance alternative solutions such as additional buses near the most affected stations. We describe statistical methods that leverage the large amount of smart-card data collected under the natural state of the system, where no shocks take place, as variables that are indicative of behavior under disruptions. We find that features extracted from the natural regime data can be successfully exploited to describe different disruption regimes, and that our framework can be used as a general tool for any similar complex transportation system.