bluuebunny/crossref_metadata_2025 huggingface dataset:
Prediction of Red Light Running Based on Statistics of Discrete Point Sensors
Authors: Zhang Liping , Zhou Kun , Zhang Wei-bin , Misener James A.
Published: January 2010

A probabilistic model is proposed to predict red light running (RLR) for collision avoidance systems at arterial signalized intersections. This RLR predictor consists of an arrival time estimator and a statistical predictor of vehicle stop-and-go maneuvers with two discrete point sensors (capable of measuring speed). In addition, unlike most prediction models, which are designed to minimize mean errors, this model identifies two types of error: the false alarm and the missed report. The capability of distinguishing these two types of error is crucial to the effectiveness of RLR-related collision avoidance systems. Therefore, the Neyman–Pearson criterion is employed: it keeps the false-alarm rate lower than a given threshold while at the same time minimizing the probability of missing error. To quantify the trade-off between these two types of error in the system design, a system operating characteristics (SOC) function is defined. The system parameters are determined by using an offline supervised parameter-setting procedure in which training data are collected from a field intersection in the San Francisco Bay Area in California with Autoscope video cameras. Effectiveness of the proposed model and its prediction algorithm are demonstrated by the collected field data. The theoretical system performance predicted by the SOC curve is matched with the evaluated performance by means of data collected from field intersections. For example, at a preset false-alarm rate of 3%, the correct prediction rate of RLR for three approaches of the field intersection ranges from 63% to 80%.
Microscopic Modeling of Traffic Signal Operations
Authors: Stevanovic Aleksandar , Abdel-Rahim Ahmed , Zlatkovic Milan , Amin Enas
Published: January 2010

Currently, there are three different methods to model traffic signal operations in microscopic simulation models: the simulation model's controller emulator, hardware-in-the-loop simulation, and software-in-the-loop simulation. Although all three methods can be based on the same industry standard code, their different implementations suggest potential operational differences. This study investigates operational differences of the three methods by examining how each method operates in five experimental scenarios. Each of the scenarios differs from the others in network size (one intersection to five intersections) and operational strategies (pretimed, actuated, actuated–coordinated, and two different signal transition logics). Ten 75-min simulation runs with 100-ms simulation resolution were executed for each experiment with the three signal control modeling alternatives. The results showed that for basic signal control operations, such as pretimed and isolated actuated operations, the three alternatives provided similar results as indicated by the average green time allocation and different operational measures of effectiveness. When advanced controller operations were used, such as signal transition logic, the simulation model emulator showed significantly different behavior than that observed in hardware-in-the-loop and software-in-the-loop simulations.
Lost Time and Cycle Length for Actuated Traffic Signal
Authors: Furth Peter G. , Cesme Burak , Muller Theo H. J.
Published: January 2010

Time within an actuated signal cycle can be decomposed into time that is fully used, which is the saturation headway multiplied by the number of passing vehicles, and time that is wasted or lost. Activity network modeling is used to show the interaction between signal timing events and traffic flow transitions. Seven components of generalized lost time are identified: those associated with start-up, minimum green, parallel queue discharge (for simultaneous gap-out), extension green, parallel extension (for nonsimultaneous gap-out), the passing of the critical gap, and phase end. Simple formulas can be used to estimate all of these components for many practical cases, allowing one to estimate average cycle length without iteration. The modeling framework accounts for the dual-ring structure with minimum green and maximum green constraints and on–off settings for recall and simultaneous gap-out. Experiments with microsimulation software verify the formulas developed. The formulas show the sensitivity of lost time, and therefore average cycle length, to parameters that a designer can control including detector setback, critical gap, gap-out settings, and number of lanes. They also show sensitivity to total demand and to the ratio of noncritical to critical phase volumes.
Proposed Concept for Specifying Vehicle Detection Performance
Authors: Middleton Dan , Longmire Ryan , Bullock Darcy M. , Sturdevant James R.
Published: January 2010

Specifications for procurement of vehicle detection systems have historically used performance comparisons with known accurate detectors, perhaps specifying one value of detection accuracy to represent several weather, lighting, and traffic conditions. In most cases, comparison with inductive loops has provided the necessary information by which to judge the performance of these detectors as either acceptable or unacceptable. However, differences in detection technologies are not adequately addressed with this method. A new concept for defining detection performance measures is proposed: it provides for some stochastic variation in sensor performance, within prescribed limits. In this case, video image vehicle detection systems (VIVDS) provide an example technology for applying this concept, but the concept is also appropriate for other technologies. Stochastic thresholds are defined that are consistent with field observation of three different VIVDS. Although these thresholds are quite large, it is believed that the combination of this new definition and a framework for defining stochastic performance will provide the basis for the detector industry to enhance its products.
Local Synchronization Control Scheme for Congested Interchange Areas in Freeway Corridor
Authors: Zhang H. Michael , Ma Jingtao , Nie Yu (Marco)
Published: January 2010

Congestion that initiates at closely spaced highway junctions and intersections, particularly freeway interchange areas, may spread and severely degrade the operational efficiency of the whole network if not handled in a timely and proper manner. A local synchronization traffic control scheme is proposed to manage queues at those critical locations through coordination of neighboring intersection traffic signals and freeway on-ramp meters. By reducing the amount of traffic feeding into and increasing the amount of traffic discharging from heavily queued sections, the scheme can prevent a queue from evolving into gridlock and thus improve overall system performance. With the help of a network kinematic wave traffic flow model, the local synchronization scheme is implemented and tested on a computer for two sample networks, one small synthetic corridor network and one large, real corridor network. The numerical results indicate that this control scheme can improve the overall operational efficiency in both corridors considerably, with as much as 50% travel time savings. This control scheme appears to perform best under incident conditions and, somewhat surprisingly, compares favorably with a more complex global optimal control scheme.
Determination of Significant Critical Movements to Generate Traffic Scenarios for Large Arterial Networks
Authors: Abdelaziz Sherif Lotfy , Abbas Montasir M. , McGhee Catherine C.
Published: January 2010

Any traffic signal control mode requires generation of multiple traffic scenarios for design purposes as well as for validation of the control system. The overall system performance depends on the traffic scenarios used to design the entire system. Therefore, all traffic patterns that might exist in a control system should be considered according to their probability of occurrence on a daily basis. However, when it comes to large networks, considering all combinations of traffic movement levels becomes time-consuming and impractical. A new approach to generate traffic scenarios for large networks is proposed. This approach is based on the selection of significant critical movements controlling the network. Selection of these critical movements is performed by using statistical correlation analysis of actual detector data and synthetic origin–destination analysis for the entire network. The proposed approach was implemented in the design of a traffic-responsive control mode for the Reston Parkway arterial network, in Northern Virginia, which has 14 intersections. Detector data were then used to validate the results of the proposed approach. The validation shows no significant difference between the actual detector data and the proposed procedure's results and therefore proves that the traffic system was correctly modeled and sufficiently represented with the proposed approach.
Evaluating Green-Extension Policies with Reinforcement Learning and Markovian Traffic State Estimation
Authors: Adam Zain M. , Abbas Montasir M. , Li Pengfi
Published: January 2010

Several protection algorithms strive to reduce the number of vehicles trapped in the dilemma zone. These algorithms use some arbitrary policies such as terminating the green when only one vehicle is present in the dilemma zone and the dilemma zone has not cleared after a certain period of time. The research proposes a control agent that is able to develop and adapt an optimal policy by learning from the environment. The agent incorporates a Markovian traffic state estimation into its learning process. A novel approach is presented for controlling traffic signals so that the number of vehicles trapped in the dilemma zone is reduced in an optimal fashion according to changes in traffic states. A comparison between the proposed optimal policy and the emerging detection-control system two-stage policy was conducted, and it was found that the policy based on reinforcement learning reduced the number of vehicles caught in the dilemma zone by up to 32%.
Development of Methodology for Toll Plaza Delay Estimation for Use in Travel Demand Model Postprocessor
Authors: Aycin Murat , Kiskel Keith , Papayannoulis Vassilis , Davies Gary
Published: January 2010

The PPSUITE program was developed for postprocessing travel demand model outputs to conduct transportation system performance and air quality conformity analyses by using the MOBILE6 vehicle emission modeling software of the Environmental Protection Agency. To account for the emissions caused by toll plaza congestion, a methodology of toll plaza delay estimation was developed as a component of PPSUITE's network operations module. This paper presents the development and application of that methodology. This tool provides a mesoscopic empirical method for estimating toll plaza delay in large-scale regional highway networks that can contain more than 100 toll plazas. The problem of analyzing each of these plazas for 24 h of the day would be impractically large or lacking in fidelity and accuracy without this tool. The methodology is also suitable for analyzing single toll plazas and time periods. In this methodology, toll plaza delay is calculated on the basis of the ratio of demand versus capacity (v/c) of the plaza for a payment type at a given time period. Depending on the v/c ratio, the plaza is in one of three states: free flow, transition, and queuing for the available payment types. Delays are calculated for these states considering the transaction times, vehicle composition, plaza approach geometry, lane use, and vehicle physical characteristics. With this methodology, a comparison of the delay estimates with estimates produced by VISSIM model of the New York–New Jersey Goethals Bridge toll plaza show that the delay methodology can accurately estimate delays for various v/c ratios.
Anticipating Welfare Impacts via Travel Demand Forecasting Models
Authors: Lemp Jason D. , Kockelman Kara M.
Published: January 2010

A great disparity exists between the direction of travel demand forecasting by researchers and the travel demand models used by transportation planning organizations. Activity-based models of travel demand have become increasingly studied in the academic realm, and significant advances have been made in recent years. However, travel demand forecasting tools used in practice have lagged and rely on traditional, aggregate four- or five-step approaches. One reason behind the divergence in methods is the lack of work that directly compares performance of the two approaches. This research provides such a comparison, with an emphasis on calculations of traveler welfare. A traditional, aggregate model and an activity-based microsimulation model of travel demand were developed in parallel by using the same data for Austin, Texas. The models were applied for a base scenario and for several policy scenarios to test model performance and sensitivity to inputs. The spatial distribution of traveler welfare implied by these scenarios illuminates a variety of key differences in the models’ performance and suggests that the activity-based model enjoys a greater sensitivity to inputs. Additional outputs demonstrate the level of segmentation that can be attained in model outputs using microsimulation methods. The comparative analysis of these two competing approaches to travel demand forecasting also offers some insight into the practical benefits of an activity-based approach.
Modeling Location Decisions of Office Firms
Authors: Elgar Ilan , Farooq Bilal , Miller Eric J.
Published: January 2010

Firm location models constitute a significant element of integrated land use and transportation models because the behavior of individuals and households is influenced by employment location. This paper examines office firm location models, both for new and relocating firms, to identify ways to improve their estimation and application. The results of the paper suggest that introduction of anchor points, such as the firm current location and the owner household location, significantly improve the estimation of office location models. A generation procedure for choice sets is then shown to improve the model's ability to replicate the decision behavior of office firms and thus provides a way to increase efficiency in the application of the model.
Lessons Learned in Developing and Applying Land Use Model Systems
Authors: Zhou Bin (Brenda) , Kockelman Kara M.
Published: January 2010

A variety of land use models is driven by theoretical advances, data availability, enhanced computation, and new policy-making needs. This paper describes the process of developing and applying a disaggregate model system that seeks to simulate the subdivision and land use change of parcels and the spatial allocation of households and employment across zones. Relying on multinomial logit specifications, random number generation, and a seemingly unrelated regression model with both spatial lag and spatial error components, the model development process was accompanied by a variety of challenges. Some issues are specific to the model presented here, but many are common for integrated transport–land use models. It is hoped that solutions to these issues and lessons learned offer useful insights for ongoing improvements in land use modeling endeavors of all types. Comparisons of road pricing and trend scenario results for the Austin, Texas, region highlight how policies may shape land and travel futures. Although the road pricing policy did not alter land use intensity patterns in a significant way, it was forecast to increase speeds across the region's network and reduce regional congestion levels.
Testing an Integrated Land Use and Transportation Modeling Framework for a Small Metropolitan Area
Authors: Voigt Brian , Troy Austin , Miles Brian , Reiss Alexandra
Published: January 2010

This paper describes the implementation of a land use and transportation modeling framework developed for Chittenden County, Vermont, to test for differences in modeled output when employing a dynamically linked travel demand model (TDM) versus an assumption of static regional accessibilities over time. With the use of the land use model UrbanSim, two versions of a 40-year simulation for the county, one with a TDM and one without, were compared. In the first version, UrbanSim was integrated with the TransCAD four-step TDM; this allowed regional accessibilities to be recalculated at regularly scheduled intervals. In the second version, TransCAD was used to compute year 2000 accessibilities; these values were held constant for the duration of the model run. The results indicated some significant differences in the modeled outputs. In particular, although centrally located traffic analysis zones (TAZs) reveal relatively little difference between the two models, the differential within peripheral TAZs is both more pronounced and more heterogeneous. The pattern displayed suggests that some peripheral TAZs have higher modeled development with a TDM because the TDM accounts for the increased proximity of destinations, thereby making them amenable to development. Meanwhile, some peripheral TAZs have lower modeled development with a TDM because they already have good accessibility (e.g., access via Interstate), but the model without the TDM does not account for increased congestion.
Calibrating a Synthetic Built Form Generator
Authors: Abraham John E. , Andersen Kristen , Clay Michael , Hunt J. D.
Published: January 2010

A system for assigning space (buildings) to parcels to establish a base-year parcel-level description of built form is described. The system was applied repeatedly to Autauga County, Alabama, where a land use–transport interaction model is being developed. The system sorts parcels according to suitability for different space types, with the details of the sorting process controlled by user parameters. Parameters were adjusted to achieve appropriate assignment in one county for which target data were available to compare the assignment with observed data. Three map comparison techniques were applied. The resulting parameters will be used in the other counties in the Montgomery, Alabama, Metropolitan Planning Organization and may be transferable to other areas in the United States. Major findings include the importance of an accurate zonal-level inventory, the usefulness of quantitative map comparisons, and the need for some information to identify vacant parcels.
Sensitivity Testing with the Oregon Statewide Integrated Model
Authors: Weidner Tara , Knudson Becky , Picado Rosella , Hunt J. D.
Published: January 2010

Oregon has a long history of developing and using integrated economic, land use–transport models. Development of the Oregon Statewide Integrated Model (SWIM) was commissioned by the Oregon Department of Transportation as part of its Transportation and Land Use Model Improvement Program within the larger Oregon Modeling Improvement Program. The first version model, now named SWIM1, has been used in numerous applications since the late 1990s. A more extensive second version, SWIM2, is now available. It uses the PECAS economic input–output activity allocation framework, an aggregate model of spatial development and microsimulation models of freight and person transport. This paper describes the work considered in the later stages of development of the SWIM2 model, including results of sensitivity testing and reports on concurrent actions to transfer the model to agency operation. The sensitivity tests considered three alternative scenarios covering the evolution of the statewide spatial economic and transport systems over a 19-year period. Each scenario was compared to a reference case. In one scenario, highway capacity was increased substantially along an Interstate corridor radiating out from the Portland metropolitan area for more than 100 mi. In the other two scenarios, the costs for vehicle travel were increased four- and 10-fold over 1998 costs. The model system was found to respond consistent with a priori expectations. Population and employment shift to areas of comparatively better accessibilities, urban densities change, trip lengths and modes change, and floor space development and prices respond to these changes in patterns that evolve across the state over time.
Applications of Integrated Transport and Gravity-Based Land Use Models for Policy Analysis
Authors: Zhou Bin (Brenda) , Kockelman Kara M. , Lemp Jason D.
Published: January 2010

Forecasting urban futures is of great importance to ensure the adequate provision of public and private services and to implement policies that guide demand while mitigating negative impacts. This study produces year 2030 predictions of land use and travel conditions across the Austin–Round Rock statistical metropolitan area of Texas by integrating a gravity-based land use model (modeled on Putman's Integrated Transportation–Land Use Package specification) with a standard travel demand model. The land use model cycles through job, household, and land consumption estimates across traffic analysis zones before feeding forward into a contemporaneous model of travel patterns. To understand the implications of different policies better, three scenarios were generated: a business-as-usual scenario, a congestion pricing plus carbon tax scenario, and an urban growth boundary (UGB) scenario. Results reveal how these transportation and land use policies may shape our land and travel futures, and they illuminate challenges and pitfalls of the gravity-based approach to land use (including the accompanying land consumption model). Of particular interest is that the imposition of road pricing (roughly 5¢/mi) had almost no discernable effect on land use predictions, yet resulted in the same predicted reduction in regional vehicle miles traveled as the UGB policy (roughly 15%).
Disappointed by Diesel?
Authors: Schipper Lee , Fulton Lew
Published: January 2010

A previous review of the trends in the sales and use of light-duty diesel-powered vehicles (diesel vehicles) in Europe through the mid-1990s questioned whether the shift toward diesel vehicles would yield large energy savings. The present study expands on the previous review. Although evidence still exists that diesel vehicles of a certain size have a substantial volumetric fuel economy advantage over gasoline-powered vehicles (gasoline vehicles) of a similar size (perhaps 30%, on average), average new diesel cars (including sport utility vehicles, personal vans, personal light trucks) and the stock of diesel vehicles on the road maintain a smaller efficiency advantage over gasoline vehicles, which, as of 2005, was on the order of 15% in most countries. When the higher energy content of diesel is considered, the fuel intensity advantages for new vehicles and vehicles already on the road shrink to less than 5% and 7% for new diesel vehicles and the stock of diesel vehicles, respectively. For new diesel vehicles, the net difference in the amount of carbon dioxide (CO2) released per kilometer (the CO2 advantage) is even less: for new cars, less than 5% in all but one country and 0%, on average, across the eight countries sampled in 2005. For the total stock of diesel vehicles on the road, diesel vehicles provide only a small reduction in emissions compared with those of gasoline vehicles. Even with normalization for the larger average size of diesel vehicles, their CO2 advantage appears to be no more than 15% to 18% for cars of a similar size class. The findings indicate that after all factors are taken into account, diesel vehicles in Europe may provide significant fuel savings to individual drivers but probably do not provide significant national energy or CO2 savings, on average, among the eight countries studied.
Estimation of Fuel Efficiency of Road Traffic by Characterization of Vehicle-Specific Power and Speed Based on Floating Car Data
Authors: Song Guohua , Yu Lei
Published: January 2010

To evaluate the fuel efficiency of road traffic, an approach that captures the characteristics of road traffic on the basis of floating car data (FCD) is proposed. In existing studies of fuel consumption, parameters such as speed, acceleration, and power demand have been adopted to represent the characteristics of traffic flows and vehicle activities. However, they are not suitable for use in the evaluation of fuel efficiency in a dynamic traffic network with various advanced traffic management alternatives. On the basis of a comprehensive analysis of the data collected by portable emission measurement systems and FCD collected in Beijing, it was found that the time distribution in vehicle-specific power (VSP) bins, that is, the VSP bin distribution, can well represent fuel consumption per unit of time. Furthermore, the combination of the VSP bin distribution and the average travel speed in a network can represent fuel consumption per unit of distance. According to these findings, the paper develops a method for evaluating the fuel efficiency for road traffic on the basis of defined indicators of fuel consumption and fuel consumption at the most efficient speed. A comparison of the estimated indicators and the real values indicates that the proposed approach performs well in evaluating the fuel efficiency of road traffic. This approach was applied to develop the temporal distribution of fuel efficiency for the West 2nd Ring Road in Beijing. Finally, the paper provides recommendations for expansion of this study by including more vehicle types and different rates of penetration of FCD.
Fuel Prices and Consumer Preferences for Vehicles
Authors: Mahadi Arliadi , Gallagher Kelly Sims
Published: January 2010

The purpose of this paper is to examine the relationship between fuel prices and consumer preferences for passenger motor vehicles in the U.S. automobile market. The paper examines the stated preferences of new vehicle owners from December 2001 to January 2008 to explore possible indications of changes in consumer preferences. Annual survey data were used. During the observation period, gasoline prices fluctuated significantly and rose to more than twice their lowest level. The importance of acquiring a vehicle with good fuel economy was analyzed, and the results of the statistical analysis are presented. The paper presents additional evidence that more consumers would state that fuel economy becomes a more important factor in their purchasing decisions as gasoline prices rise. The evidence also supports the suggestion that the financial impact of fuel economy will matter first to lower-income buyers as gasoline prices rise.
Potential of Plug-In Hybrid Electric Vehicles to Reduce Petroleum Use
Authors: Vyas Anant D. , Santini Danilo J. , Johnson Larry R.
Published: January 2010

This paper delineates the various issues involved in developing reliable estimates of the petroleum use reduction that would result from the widespread introduction of plug-in hybrid electric vehicles (PHEVs). Travel day data from the 2001 National Household Travel Survey (NHTS) were analyzed to identify the share of vehicle miles of travel (VMT) that could be transferred to grid electricity. Various PHEV charge-depleting (CD) ranges were evaluated, and 100% CD mode and potential blended modes were analyzed. The NHTS data were also examined to evaluate the potential for PHEV battery charging multiple times a day. Data from the 2005 American Housing Survey (AHS) were analyzed to evaluate the availability of garages and carports for at-home charging of the PHEV battery. The AHS data were also reviewed by census region and household location within or outside metropolitan statistical areas. To illustrate the lag times involved, the historical new vehicle market share increases for the diesel power train in France (a highly successful case) and the emerging hybrid electric vehicles in the United States were examined. A new vehicle technology substitution model is applied to illustrate a historically plausible successful new PHEV market share expansion. The trends in U.S. light-duty vehicle sales and light-duty vehicle stock were evaluated to estimate the time required for hypothetical successful new PHEVs to achieve the ultimately attainable share of the existing vehicle stock. Only when such steps have been accomplished will the full oil savings potential for the nation be achieved.
Early U.S. Market for Plug-In Hybrid Electric Vehicles
Authors: Axsen Jonn , Kurani Kenneth S.
Published: January 2010

Plug-in hybrid electric vehicles (PHEVs) are proposed as both a near-term technology to achieve energy and environmental goals and as a transitional step toward viable all-electric vehicles. To replace assumptions with observations of potential PHEV drivers’ behavior in market and impact analyses, an Internet-based survey of 2,373 new-car–buying households in the United States was conducted. The instrument required households to answer questions, complete a driving and parking diary, and then complete several PHEV design exercises. Three conclusions could be drawn from the resulting data. First, at least half of the target population is already equipped for at-home vehicle recharging but has little opportunity for recharging at the workplace or other locations. Second, the study found that the respondents had widely varied interests in four possible PHEV attributes: fuel economy (in both charge-depleting and charge-sustaining operations), blended versus all-electric operation, the distance over which the vehicle is in the charge-depleting mode, and the recharging speed. Nevertheless, the appeal of increased fuel economy appears to be the highest and that of faster recharging appears to be the lowest. Furthermore, there is little interest in all-electric operation. Third, given the previous two points, it was estimated that about a third of the target population has both the infrastructure to recharge a PHEV and interest in a vehicle with plug-in capabilities. Policy, technology, and energy providers may use this information to understand whether their plans, designs, and goals align with these present understandings or whether it would be collectively beneficial to foster new understandings of PHEVs among U.S. car buyers.
Meeting the Challenge of Institutional Fragmentation in Addressing Climate Change in Transportation Planning and Investment
Authors: Plumeau Peter , Lawe Stephen
Published: January 2010

Global climate change (GCC) has emerged in recent years as the highest-profile environmental issue of the early 21st century. Transportation institutions at all levels of government face significant challenges in effectively addressing GCC in terms of both the adaptation of the transportation system to the impacts of GCC and the mitigation of transportation's contribution to GCC. These challenges stem in large part from the fragmentation of decision making within and across governmental levels, the consequent mismatch of political boundaries, and the nature of options for effectively addressing GCC. This paper discusses these challenges and proposes a conceptual framework for rethinking how transportation institutions may more effectively address the connection between transportation and GCC. It includes an assessment of the current state and metropolitan planning activities related to GCC and the perspectives of various planning practitioners from across the United States. It also articulates several of the key institutional elements necessary for a GCC-responsive transportation agency, including entrepreneurial leadership, an appropriate geographic jurisdiction, a multi-disciplinary organizational structure, appropriately aligned funding and planning structures, and adequate planning and implementation authority. Finally, it also offers several suggestions on potential research needs associated with climate change and transportation institutional change.
“Hockey Sticks” Made of Carbon
Authors: Brand Christian
Published: January 2010

Personal transportation accounts for the majority of greenhouse gas emissions from the transportation sector, in particular, when international aviation is included, yet relatively little is known about the composition and socioeconomic makeup of travel emissions at the household and individual levels. Do they vary by choice of transportation mode, geographical location, socioeconomic factors, vehicle technology choice, and other personal characteristics and if so, by how much? This paper aims to shed some light on the profile of greenhouse gas emissions at the disaggregate level. It presents the results of a substantive case study, performed in the United Kingdom, based on a newly developed greenhouse gas emissions evaluation tool. When all known climate effects are accounted for, however uncertain they may be, air travel dominates overall as the source of greenhouse gas emissions from personal travel. There is a huge range in emissions, with the highest 20% of emitters producing 61% of emissions. This 61% to 20% emission rule is mirrored in the “hockey-stick” shape of the curves ranking respondents by their emissions levels, which is surprisingly similar when transportation modes, location, and unit of analysis (individual, household) are compared. Although income, working status, age, and car ownership are significantly related to overall emissions, factors related to accessibility, household location, and gender are not. The paper concludes by discussing methodological considerations and policy implications.
Trade-Off between Carbon Dioxide Emissions and Logistics Costs Based on Multiobjective Optimization
Authors: Kim Nam Seok , Janic Milan , van Wee Bert
Published: January 2010

This paper examines the relationship between the freight transport costs and the carbon dioxide (CO2) emissions in given intermodal and truck-only freight networks. When the trade-off, which is represented as the relationship, is changed, the freight mode share and route choice are also modified. To show the ever changing trade-off and mode and route choice, a decision-support tool was developed. The given intermodal freight networks represent different freight combinations (i.e., a truck-only system, a rail-based intermodal system, and a short sea-based intermodal system). Because CO2 constraints in logistics markets will need to be realized in the near future, a modal shift in freight transportation could be expected to reduce the CO2 emissions within the reasonable cost and time constraints. The technique of multiobjective optimization is used as the core of the decision-support tool for clarifying the relationship. The tool that was developed is applied to a simplified freight transport network connecting two large European ports: the Port of Rotterdam (the Netherlands) and the Port of Gdansk (Poland). The initial solution, based on the minimization of freight costs, shows that the mode share of freight is local and regional freight transportation situations, whereas the other solutions balanced with CO2 emissions show that the mode share is changed into an intermodal freight system, which is based on a hub-and-spoke network. In considering the changing demands and capacities of freight systems, five scenarios are tested to examine the impact of mode and route change on the trade-off. The results of scenario analyses show that the trade-off is significantly influenced by the demands and capacities of systems.
Impacts of a Carbon Dioxide Emissions Trading Scheme in German Road Transportation
Authors: Jochem Patrick
Published: January 2010

To attempt to counter the possible impacts of global warming, the European Union decided to ratify the Kyoto Protocol and promised to reduce its carbon dioxide (CO2) emissions by 8%, compared with 1990 levels, by 2010. One of the policies that has been implemented to achieve this is the European Emission Trading Scheme (ETS) for CO2 certificates. So far, the transportation sector, which contributes about 28% of European CO2 emissions, has been exempt from ETS, although a further increase in CO2 emissions from the transportation sector is expected in the coming years. Furthermore, this is the only sector in which emissions have increased (by about 32% since 1990). The inclusion of road transportation in ETS is feasible after 2012. A partial mesoeconomic model was used to assess the impacts of a CO2 emissions trading scheme in German road transportation. A hypothetical CO2 emissions trading scheme with an open alternative and a closed alternative was applied to the simulated German road transportation sector. The effects on certificate prices and fuel demand as a result of the individual reactions of households and freight forwarders were calculated. It became apparent that from the current perspective the willingness of households to pay for prestigious (but fuel-inefficient) cars is outweighed by technical mitigation costs in other sectors. Thus, in an open trading scheme without major changes in transportation demand, the main effect will be steady CO2 emissions in road transportation but large payments to other sectors for mitigation.
Achieving Carbon-Efficient Transportation
Authors: Hickman Robin , Ashiru Olu , Banister David
Published: January 2010

Transportation is a major user of carbon-based fuels and is increasingly being highlighted as the sector that contributes the least to carbon dioxide (CO2) emission reduction targets. This paper reports on the findings of the current Visioning and Backcasting for Transport in London study, which considers the role of the transportation sector in reducing CO2 emissions in London. A backcasting study approach was used, and the likely impacts of alternative images of 2025 were tested. A transportation and carbon simulation game was also developed for London. Within this game, users are able to consider a series of potential policy packages, such as low-emission vehicles, alternative fuels, pricing regimens, public transportation, walking and cycling, strategic and local urban planning, information and communication technologies, smarter choices, ecological driving and slower speeds, long-distance travel substitution, freight transportation, and international air, and select various levels of application to help achieve headline CO2 emissions reduction targets. The roles of two external enabling measures, carbon rationing and oil pricing, were also considered. The paper considers an optimized policy package for 2025. A deep reduction in CO2 emissions from the transportation sector is theoretically possible, yet difficult to achieve. The main perceived problem is in engendering an interest in the public to change consumer purchases and behaviors. The huge challenge now is to map out and discuss a variety of policy pathways to carbon efficiency in the transportation sector and then to enable and achieve a level of consumer and behavioral change consistent with strategic aspiration.
Enzymatic Biofuel Cells—Fabrication of Enzyme Electrodes
Authors: Hao Yu Eileen , Scott Keith
Published: January 2010

Enzyme based bioelectronics have attracted increasing interest in recent years because of their applications on biomedical research and healthcare. They also have broad applications in environmental monitoring, and as the power source for portable electronic devices. In this review, the technology developed for fabrication of enzyme electrodes has been described. Different enzyme immobilisation methods using layered structures with self-assembled monolayers (SAM) and entrapment of enzymes in polymer matrixes have been reviewed. The performances of enzymatic biofuel cells are summarised. Various approaches on further development to overcome the current challenges have been discussed. This innovative technology will have a major impact and benefit medical science and clinical research, healthcare management, energy production from renewable sources.
The Diverse Applications of Cladistic Analysis of Molecular Evolution, with Special Reference to Nested Clade Analysis
Authors: Templeton Alan R.
Published: January 2010

The genetic variation found in small regions of the genomes of many species can be arranged into haplotype trees that reflect the evolutionary genealogy of the DNA lineages found in that region and the accumulation of mutations on those lineages. This review demonstrates some of the many ways in which clades (branches) of haplotype trees have been applied in recent years, including the study of genotype/phenotype associations at candidate loci and in genome-wide association studies, the phylogeographic history of species, human evolution, the conservation of endangered species, and the identification of species.
Quantum Dots—From Synthesis to Applications in Biomedicine and Life Sciences
Authors: Drummen Gregor  P.C.
Published: January 2010

Imagine devices or particles so small that they are invisible to the naked eye. Imagine that such entities could be used to patrol our bodies and autonomously augment endogenous defense and repair mechanisms. Imagine the defeat of illness at a fraction of the current costs. Bionanotechnology is the field of science that deals with just that: the development of imaging, tracking, targeting, sensing, diagnostic, and eventually therapeutic capabilities based on particles in the nanometer range, i.e., “nanoparticles”. Within the extensive group of nanoparticles, semiconducting quantum dots play a central and prominent role. Quantum dots excel at a myriad of physical properties, most notably their fluorescent properties, such as high quantum yield, photo-stability, broad absorption spectra, and their remarkable size-dependent emission-tunability.
Development of a Novel Catalytic Membrane Reactor for Heterogeneous Catalysis in Supercritical CO2
Authors: Islam Nazrul  M. , Chatterjee Maya , Ikushima Yutaka , Yokoyama Toshiro , Kawanami Hajime
Published: January 2010

A novel type of high-pressure membrane reactor has been developed for hydrogenation in supercritical carbon dioxide (scCO2). The main objectives of the design of the reactor are the separate feeding of hydrogen and substrate in scCO2 for safe reactions in a continuous flow process, and to reduce the reaction time. By using this new reactor, hydrogenation of cinnamaldehyde into hydrocinnamaldehyde has been successfully carried out with 100% selectivity at 50 °C in 10 MPa (H2: 1 MPa, CO2: 9 MPa) with a flow rate of substrate ranging from 0.05 to 1.0 mL/min.
Host-Guest Complexation Studied by Fluorescence Correlation Spectroscopy: Adamantane–Cyclodextrin Inclusion
Authors: Granadero Daniel , Bordello Jorge , Pérez-Alvite Maria Jesus , Novo Mercedes , Al-Soufi Wajih
Published: January 2010

The host-guest complexation between an Alexa 488 labelled adamantane derivative and β-cyclodextrin is studied by Fluorescence Correlation Spectroscopy (FCS). A 1:1 complex stoichiometry and a high association equilibrium constant of K = 5.2 × 104 M-1 are obtained in aqueous solution at 25 °C and pH = 6. The necessary experimental conditions are discussed. FCS proves to be an excellent method for the determination of stoichiometry and association equilibrium constant of this type of complexes, where both host and guest are nonfluorescent and which are therefore not easily amenable to standard fluorescence spectroscopic methods.
The Effect of Liquid Crystalline Structures on Antiseizure Properties of Aqueous Solutions of Ethoxylated Alcohols
Authors: Wlodzimierz Sulek Marian , Bak Anna
Published: January 2010

Aqueous solutions of ethoxylated alcohols which form lyotropic liquid crystals at high concentrations (40–80%) were selected as model lubricating substances. Microscopic studies under polarized light and viscosity measurements were carried out in order to confirm the presence of liquid crystalline structures in the case of alcohol solutions with ethoxylation degrees of 3, 5, 7 and 10. Microscopic images and viscosity coefficient values characteristic of various mesophases were obtained. As expected, the viscosity of LLCs decreases considerably with an increase in shearing rate which is characteristic of liquid crystals being non-Newtonian liquids. Antiseizure properties were determined by means of a four-ball machine (T-02 Tester) and characterized by scuffing load (Pt), seizure load (Poz) and limiting pressure of seizure (poz). Alcohol ethoxylates forming mesophases in aqueous solutions have the strongest effect on the Pt values which are several times higher than those measured in the presence of water. Ethoxylates with higher degrees of ethoxylation exhibit higher values of scuffing load. Those changes have been interpreted as a result of higher cloud points at which those compounds lose their amphiphilic properties. In general, the presence of mesophases in the bulk phase and particularly in the surface phase may lead to the formation of a lubricant film which separates the frictionally cooperating elements of a friction pair. The antiseizure efficiency of alcohol solutions is highest up to the load value which does not exceed the scuffing load value.
Functionalization of Artificial Freestanding Composite Nanomembranes
Authors: Jakšić Zoran , Matovic Jovan
Published: January 2010

Artificial nanomembranes may be defined as synthetic freestanding structures with a thickness below 100 nm and a very large aspect ratio, of at least a few orders of magnitude. Being quasi-2D, they exhibit a host of unusual properties useful for various applications in energy harvesting, sensing, optics, plasmonics, biomedicine, etc. We review the main approaches to nanomembrane functionalization through nanocompositing, which ensures performance far superior to that of simple nanomembranes. These approaches include lamination (stacking of nanometer-thin strata of different materials), introduction of nanoparticle fillers into the nanomembrane scaffold, nanomembrane surface sculpting and modification through patterning (including formation of nanohole arrays and introduction of ion channels similar in function to those in biological nanomembranes). We also present some of our original results related to functionalization of metal matrix composite nanomembranes.
Families of Molecular Hexa- and Trideca-Metallic Vanadium(III) Phosphonates
Authors: Khanra Sumit , Shaw Rachel , Helliwell Madeleine , Tuna Floriana , Muryn Christopher A. , McInnes Eric J. L. , Winpenny Richard E. P.
Published: January 2010

The synthesis and structural characterization of two families of low-valent vanadium(III) {V6P4} and vanadium(III/IV) {V13P8} phosphonate complexes are reported. Magnetic characterization is reported for representative examples.
Description of Extrudate Swell for Polymer Nanocomposites
Authors: Wang Kejian
Published: January 2010

Extrudate swell is often observed to be weakened in nanocomposites compared to the pure polymer matrix. A theory quantifying this would be significant either for optimum processing or for understanding their viscoelasticity. A unified extrudate swell correlation with material properties and capillary parameters was suggested for polymer melt and their nanocomposites when considering the reservoir entry effect. More importantly, it was the first to find that the composite swell ratio can be the matrix swell ratio multiplied by the concentration shift factor, which is similar to the dynamic moduli expression for composites. The factor is a function of the shear field (stress or shear rate), filler content, filler internal structure and the surface state as well as the matrix properties. Several sets of swell data for nanocomposites were chosen from publications to test the new theories. The proposed quantitative model displayed good fit for the five kinds of nanocomposites, which verified the rationality of the swell theory for nanocomposites.
Synthetic Fabrication of Nanoscale MoS2-Based Transition Metal Sulfides
Authors: Wang Shutao , An Changhua , Yuan Jikang
Published: January 2010

Transition metal sulfides are scientifically and technologically important materials. This review summarizes recent progress on the synthetic fabrication of transition metal sulfides nanocrystals with controlled shape, size, and surface functionality. Special attention is paid to the case of MoS2 nanoparticles, where organic (surfactant, polymer), inorganic (support, promoter, doping) compounds and intercalation chemistry are applied.