bluuebunny/crossref_metadata_2025 huggingface dataset:
Conditions on the Formation of Middles in Russian
Authors: Jones Charles , Levine James S.
Published: February 2011

This paper presents a VP account of the adverbial modification required, in some way, by the middle construction in Russian and the related construction in English: Kartoška počistilas' legko 'The potato peeled easily.' The account develops a syntax and semantics for the adverbial middle (Type I: Ackema and Schoorlemmer 2006) that is free of various requirements often supposed for it, notably an "implicit agent" and a generic interpretation. The main condition on adverbial middle formation is access to an embedded state predicate of the object in the logical structure of the head.
Performance Evaluation of Recycled PMA Binders Containing Warm Mix Asphalt Additives
Authors: Kim Hakseo , Lee Soon-Jae , Amirkhanian Serji N. , Park Tae-Soon
Published: February 2011

The performance properties of recycled polymer modified asphalt (PMA) binders containing warm mix asphalt (WMA) additives at high, intermediate, and low temperatures were evaluated. First, each combination of two PMA binders (performance grade (PG) 76-22 from two different sources) and two WMA additives (i.e., Aspha-min® and Sasobit®) were blended to produce warm PMA binders. They were then artificially short-term and long-term aged through the rolling thin film oven and pressure aging vessel procedures. Second, long-term aged warm PMA binders were recycled using two virgin binders (PG 76-22 and PG 70-22), and the recycled binders were artificially aged again. Lastly, Superpave binder tests were performed through the rotational viscometer, the dynamic shear rheometer (DSR), and the bending beam rheometer (BBR). In general, the results of this study suggested that (1) the WMA additives and the aged PMA binders were found to have a significant influence on the performance properties of recycled binders (measured by the DSR and the BBR); (2) the use of PG 70-22 as a virgin binder was effective in offsetting the increase of binder stiffness due to the additives and the aged binders; and (3) the recycled warm PMA binders can result in satisfactory binder performance that meets current Superpave binder requirements.
Efficient Tool Replacement Procedure Based on Yield Evaluation
Authors: Lin Chen-ju , Pearn W. L.
Published: February 2011

Tool wear is an inevitable problem in many machining processes. The problem constitutes an inseparable component of variation and can be considered as a systematic assignable cause of process variability. Tool replacement should be initiated when the yield drops below a certain level. Determining the best time for tool replacement is essential to balance between production quality and tool utilization. The yield index, Spk, has been effectively applied to assess the yield of processes. However, its ordinary measure is inaccurate when data is contaminated by inseparable nonrandom variation. Yield evaluation becomes imprecise when a process is subjected to the tool wear problem. Thus, this paper presents an efficient procedure that determines the best time to replace tools under an extremely low fraction of defectives. The variation from assignable causes is removed by using the linear regression technique. A modified estimator of the Spk index with its distribution is proposed to evaluate the processes with the tool wear problem.
Microarray assessment of the influence of the conceptus on gene expression in the mouse uterus during decidualization
Authors: McConaha M E , Eckstrum K , An J , Steinle J J , Bany B M
Published: February 2011

During pregnancy in several species including humans and rodents, the endometrium undergoes decidualization. This process of differentiation from endometrial to decidual tissue occurs only after the onset of implantation in mice. It can also be artificially induced causing the formation of deciduomal tissue. The purpose of this study was to compare the gene expression profile of the developing decidua in pregnant mice with the deciduoma formed after artificial induction in an effort to identify conceptus-influenced changes in uterine gene expression during decidualization. We induced decidualization artificially by transferring blastocyst-sized ConA-coated agarose beads into the uterus on day 2.5 of pseudopregnancy. Recently published work has found this model to be more ‘physiological’ than other methods. Total RNA was isolated from blastocyst and bead-induced ‘implantation’ sites of the uteri of day 7.5 pregnant (decidua) and pseudopregnant (deciduoma) mice respectively. This RNA was then used for microarray analysis using Mouse Illumina BeadArray chips. This analysis revealed potential differential mRNA levels of only 45 genes between the decidua and bead-induced deciduoma tissues. We confirmed the differential mRNA levels of 31 of these genes using quantitative RT-PCR. Finally, the level and localization of some of the mRNAs for select genes (Aldh3a1,Bcmo1,Guca2b, andInhbb) identified by our microarray analysis were examined in more detail. This study provides the identity of a small set of genes whose expression in the uterus during decidualization may be influenced by molecular signals from the conceptus.
Two decades of great postsocialist transformation — And what next?
Authors: Kolodko G.
Published: February 2011

The progress of post-socialist systemic transformation should be evaluated through the prism of its influence on a country’s development abilities. During twenty years of comprehensive systemic shift, gross domestic product has increased only to a limited degree, on a par with the growth of the world economy. While judging the transformation progress, not only the improvement of competitiveness and growth in terms of quantity must be taken into account, but also social and cultural aspects. Had there been a better policy co-ordination of systemic change and socio-economic development, GDP could have increased by a considerable amount more. This opportunity has been missed due to the implementation of sub-optimal if not just wrong economic policies based on wrong economic theories and the lack of ability of the ruling elites to overrun the conflicts of interests.
Individual rights as a factor of economic convergence
Authors: Czeglédi P.
Published: February 2011

This paper attempts to contribute to the understanding of how democracy and individual rights associated with it affect economic development. The market process approach to innovation (and entrepreneurship) is combined with the stationary bandit approach to property rights to derive a proposition concerning how the lack of exogenous constraints on the government can retard innovation. According to this, a credible commitment to secure property rights through respecting individual or human rights becomes an important factor for the process of catching up for those countries that are relatively close to the most developed ones in terms of technology and thus income. The proposition is tested on cross-country panel data using a measure of civil rights as a proxy for the commitment to secure individual rights. This argument provides one possible explanation for the fact that there is a strong correlation between democracy and income while the correlation between democracy and growth is weak.
Is exit a firm failure? Facts and theory
Authors: Marques A. , BrandÃo A.
Published: February 2011

Literature on firms’ entry and exit decisions provides empirical evidence that industries with many exits also have many entries. We present a paper that merges some different approaches to the entry and exit of firms and which proposes a new method for looking at the entrepreneurial decision. Our model theoretically supports what empirical evidence has shown and holds; that databases are not yet developed enough to understand the whole exit process. We demonstrate that the possibility of recovering some share of investment costs makes entry more than just a production decision. Within a defined time horizon, a firm can enter the market despite making a loss from production output since the firm’s return consists of both sales and investment cost recovery. Entry may be the optimal strategy even when the unit cost is higher than the market price.
Human resource management practices of large multinational firms in Hungary, 1988–2005
Authors: Poór J. , Engle A. , Gross A.
Published: February 2011

A model of human resource (HR) practices in the subsidiary units of multinational corporations (MNC’s) in Hungary was developed from a review of the literature. This model describes the evolution of different HR variables in the light of external (macro) and internal (firm specific) factors. Based on components of this model, an interview-based survey of top level HR executives at 42 subsidiaries of large multinational companies in Hungary was completed. Results suggest that local subsidiary HR executives still maintain significant authority over their functional processesvis-à-visthe corporate office and expatriates are used less now than in earlier stages of development. Critical issues facing these executives varied by stage of competitive development between 1988 and 2005, HR staff continue to have significant in-country head counts, consulting is largely limited to training and development activities and most privately owned subsidiaries perceive unions as a marginal institution in Hungary today. The paper concludes with a series of limitations based on the interview processes and small sample size and a discussion of areas for further regional and national research development relevant to the model.
[NO TITLE AVAILABLE]
Authors: Maciel Danielli Barreto , Medeiros Lílian Vieira de , Medeiros Vivian Vieira de , Leão Mariele Porto Carneiro , Camargo Luis Eduardo Aranha , Oliveira Neiva Tinti de
Published: February 2011

Studies were performed to analyze the genetic characterization using RFLP-ITS and Intron (primer EI1) markers and the amplification of the cap20 pathogenicity gene by PCR in Colletotrichum gloeosporioides isolates of different hosts plant. The genetic variability was accessed using RFLP-ITS and Intron markers and grouping by UPGMA method. Primers to cap20 gene were constructed using selected sequences of the GenBank (National Center of Biotechnology Information, http://www.ncbi.nlm.nih.gov) with the Primer 3 program. The dendrograms analysis showed that the RFLP-ITS marker was more informative to separate the Colletotrichum sp, and that primer EI1 demonstrated greater genetic diversity. The amplification of the DNA of the Colletotrichum isolates to the cap20 gene with primers P1 and P2 indicated that this gene could present variations into C. gloeosporioides related with the host, and also that it was present in other Colletotrichum sp.
Flood, Disaster, and Turmoil: Social Issues in Cleft and Craniofacial Care and Crisis Relief
Authors: Strauss Ronald P. , Van Aalst John A. , Fox Lynn , Stein Margot , Moses Michael , Cassell Cynthia H.
Published: February 2011

Objective

To examine social issues in the conduct of cleft and craniofacial care through relief programs in disrupted crisis contexts.

Method

Social, health policy, and ethical analyses.

Results

At best, craniofacial team care is multidisciplinary, coordinated, and sustained, requiring a long-term relationship between team members, patients, and families. Disasters and societal turmoil interrupt such relationships, causing craniofacial care to become a secondary concern. Providing craniofacial team care in a crisis setting requires rebuilding disrupted coordination and communication. Crisis relief care involves a complex set of expectations and responsibilities and raises issues such as (1) quality assurance, infection control, appropriate standards of care, and follow-up care/continuity; (2) equity of access to services and clinical ethics in the context of war and/or deprivation; (3) training of visitors in the local nation or site; (4) disciplinary composition of teams, interprofessional communication/rivalry, and credentials of clinicians; (5) ownership of the site and local visitor relations; (6) fundraising and marketing strategies; and (7) ethical issues in the doctor-patient relationship.

Conclusions

Specific ethical standards for international cleft and craniofacial care delivery also apply to domestic and global crisis relief contexts. Guidance on issues related to professional experience, informed consent, and continuity of care will help care providers address social and ethical issues raised in crisis relief programs. This paper proposes that the Position Paper of the American Cleft Palate-Craniofacial Association (ACPA) on International Treatment Programs should be used as a template to develop and disseminate a set of standards that apply to crisis relief.
Simultaneous Increase in Gas and Liquid Relative Permeabilities and Reduction of High-Velocity Coefficient From Wettability Alteration
Authors: Wu Stanley , Firoozabadi Abbas
Published: February 2011

The alteration of the wettability from liquid-wetting to intermediate gas-wetting results in improved liquid mobility, which has been demonstrated by a number of authors in recent years. In this work, we show that the gas-phase mobility may either increase or decrease in the state of intermediate gas-wetting. The increase or decrease in the gas-phase mobility is a function of the minimum liquid saturation. We also confirm that, as a result of the wettability alteration, there may be a substantial decrease in the two-phase high-velocity coefficient compared to the unaltered wettability state. The increase in the gas- and liquid-phase relative permeabilities and a decrease in the high-velocity coefficient of the two-phase flow from the wettability alteration contribute to improved gas well productivity.
Study of Diffusivity of Hydrocarbon Solvent in Heavy-Oil Saturated Sands Using X-Ray Computer Assisted Tomography
Authors: Luo Hongtao , Kantzas Apostolos
Published: February 2011

Hydrocarbon solvent-assisted processes are thought to be effective EOR technologies for heavy oil and bitumen production. In order to describe those processes quantitatively, the diffusivity of hydrocarbon solvent in oil sands is a crucial required parameter.

Computer-assisted tomography (CAT), as a nonintrusive method, is a useful tool to obtain the physical properties of cores (density, porosity, heterogeneities) and the fluids within the cores (saturation or concentration profiles). However, the concentration profiles obtained from diffusion experiments of solvent in oil sands were fluctuating and could not be used to evaluate the diffusivity. In order to solve the problem, during the data processing of CAT scanning, porosity heterogeneity of porous media and volume changes on mixing are considered to improve the accuracy of concentration profiles dramatically. Subsequently, the diffusivity of hydrocarbon solvent in heavy-oil saturated sands is determined based on an updated mathematical model, which considers porosity heterogeneity of porous media in the major diffusion direction and volume changes on mixing. Thus, the diffusivity as a function of concentration and porosity is evaluated precisely and the impact of porosity heterogeneity of porous media on diffusivity determination of hydrocarbon solvent in heavy-oil saturated sands is investigated.
Identification of Metabolic Modifiers That Underlie Phenotypic Variations in Energy-Balance Regulation
Authors: Chang Chia Lin , Cai James J. , Cheng Po Jen , Chueh Ho Yen , Hsu Sheau Yu Teddy
Published: February 2011

OBJECTIVE

Although recent studies have shown that human genomes contain hundreds of loci that exhibit signatures of positive selection, variants that are associated with adaptation in energy-balance regulation remain elusive. We reasoned that the difficulty in identifying such variants could be due to heterogeneity in selection pressure and that an integrative approach that incorporated experiment-based evidence and population genetics-based statistical judgments would be needed to reveal important metabolic modifiers in humans.

RESEARCH DESIGN AND METHODS

To identify common metabolic modifiers that underlie phenotypic variation in diabetes-associated or obesity-associated traits in humans, or both, we screened 207 candidate loci for regulatory single nucleotide polymorphisms (SNPs) that exhibited evidence of gene–environmental interactions.

RESULTS

Three SNPs (rs3895874, rs3848460, and rs937301) at the 5′ gene region of human GIP were identified as prime metabolic-modifier candidates at the enteroinsular axis. Functional studies have shown that GIP promoter reporters carrying derived alleles of these three SNPs (haplotype GIP−1920A) have significantly lower transcriptional activities than those with ancestral alleles at corresponding positions (haplotype GIP−1920G). Consistently, studies of pregnant women who have undergone a screening test for gestational diabetes have shown that patients with a homozygous GIP−1920A/A genotype have significantly lower serum concentrations of glucose-dependent insulinotropic polypeptide (GIP) than those carrying an ancestral GIP−1920G haplotype. After controlling for a GIPR variation, we showed that serum glucose concentrations of patients carrying GIP−1920A/A homozygotes are significantly higher than that of those carrying an ancestral GIP−1920G haplotype (odds ratio 3.53).

CONCLUSIONS

Our proof-of-concept study indicates that common regulatory GIP variants impart a difference in GIP and glucose metabolism. The study also provides a rare example that identified the common variant-common phenotypic variation pattern based on evidence of moderate gene–environmental interactions.
Function of coprophagous beetles (Coleoptera: Scarabaeidae, Geotrupidae, Hydrophilidae) in cattle pastures inferred from pitfall trapping data
Authors: Šlachta Martin , Frelich Jan , Tonka Tomáš
Published: February 2011

Function of coprophagous beetles (Coleoptera: Scarabaeidae, Geotrupidae, Hydrophilidae) in cattle pastures inferred from pitfall trapping data

An analysis of data on the dry weight biomass of coprophagous beetles in standardized dung (4.5 l) was conducted in order to characterize the spatial and the seasonal distribution of the beetles' biomass in cattle pastures and to elucidate their function in dung decomposition. Nested Anova with factors of farm, site (nested in farm), seasonal period and year was used to evaluate the effect of these factors on the biomass of four functional species groups: the dung dwellers ofScarabaeidae(subfamilyAphodiinae), the dung dwellers ofHydrophilidae, the small tunnellers ofScarabaeidae(subfamilyCoprinae) and the large tunnellers ofGeotrupidae. The spatial variation of biomass (between the sites and the farms) was insignificant (P>0.05) in the two dung-dweller groups and in the large-tunnellers group. On the other hand, a significant (P<0.05) seasonal variation of biomass was found in all but the large tunneller group. In dung dwellers, the spring biomass was formed mainly by two species,Aphodius prodromusandA. sphacelatus. In summer, most of the biomass was accounted for bySphaeridium lunatum, S. scarabaeoidesandA. rufipes. In the two tunneller groups,Onthophagus fracticornis, Geotrupes stercorariusandG. spinigerformed a majority of the biomass in dung.
Results of robotic milking on selected farms in the Czech Republic
Authors: Voříšková Jarmila , Maršálek Miroslav , Reichová Sandra , Zedníková Jana , Machálek Antonín
Published: February 2011

Results of robotic milking on selected farms in the Czech Republic

The introduction of robotic milking into farms in the Czech Republic began in 2003. This paper gives the results on 7 farms with robotic milking machines, with regard to breed (Bohemia Spotted cattle, Holstein), company size (number of robots 1 to 8) and type of ownership (private, cooperative). All farms used Lely Astronaut A3 robots. The companies showed statistical differences in average daily milk performance (P≤0.001) from 21.04 kg of milk/head/day to 40.43 kg of milk/head/day. Small private companies with one robot reached significantly (P≤0.001) higher milk performance of 28.79 kg of milk/head/day. On average, the daily milk performances of the Holstein cattle were 7.17 kg of milk higher than those of the Bohemia Spotted cattle (29.97 kg and 22.80 kg, respectively). The average number of milkings per head and day in individual companies ranged from 1.97 to 2.67. The average number of rejections per head and day (1.11) was low in companies with one robot and is influenced by the number of cows per one robot. The highest number of cows that had to be accompanied to the robot could be seen in large cooperatives - 20.1%. Bohemia Spotted cattle showed the lowest number of breeding-cows needing to be accompanied to the robot (8.8%).
Contribution to the diversity of soil mites (Acari, Gamasida) in southern Croatia (Dalmatia), with some ecological and zoogeographical notes
Authors: Kaczmarek Sławomir , Marquardt Tomasz
Published: February 2011

Contribution to the diversity of soil mites (Acari, Gamasida) in southern Croatia (Dalmatia), with some ecological and zoogeographical notes

The species diversity of soil gamasid mites (Acari) in southern Croatia (Dalmatia) was studied in August 2002. In the Krka National Park, Brač Island, and near the town of Makarska, 320 samples were collected from various microhabitats: soil, grass and moss ground cover, wet moss, needle litter, moss covering tree trunks, and decaying wood). Altogether, 2097 mites of 56 gamasid species were recorded. Dominant species were: Polyaspis patavinus (Brač Island), Zercon fageticola (Makarska), and Cheiroseius serratus (Krka National Park). Analyses of ecological preferences and zoogeographic distribution were made for Polyaspis patavinus, Cheiroseius serratus, Zercon fageticola, Z. berlesei, Z. athiasi, Asca nova and A. aphidioides.
Undressing
Authors: Yamamoto Maiko Bae
Published: February 2011

Undressing looks at Theatre Replacement's latest performance and the many roles memory plays in building a work from specific biographical material, in this case significant pieces of clothing. The process to date has the collaborators navigating questions around what serves an overall narrative structure versus what is their responsibility to the truth and the subjects who quite literally gave them the shirts off their backs.
Dear Citizens of Tennessee
Authors: Long James
Published: February 2011

In 2008, Vancouver-based Theatre Replacement began the process of interviewing citizens in a series of small towns in Tennessee that shared the same name as famous cities elsewhere in the world. These interviews were heavily edited and then developed into a performance text for The Greatest Cities in the World, which opened March 2010. The performance focused on a number of highly provocative topics covered in the collected interviews including racism and violence. The following letter is addressed to the citizens of Tennessee and attempts to explain why certain choices were made in the editing of the interviews and creation of the work, choices that likely did not honour the memories shared by the citizens of Tennessee.
Before we get into the event—I would like to hear from you in what way you think that my love affected you
Authors: Youssef Marcus
Published: February 2011

Throughout his mother's decade-long battle with early onset Alzheimer's disease, Marcus Youssef has used multiple narrative forms to document his experience of his mother's illness. Using examples of his own writing about her Alzheimer's, as well as the writing his mother did as the disease took hold, Youssef examines the ways in which his own attempts to construct performance narratives out of the disease's impact seem remarkably similar to his mother's own attempts to preserve a sense of narrative (or “self”) in the face of the steady erasure of her memory. Taken together, these fragments of essay, drama, journal and radio broadcast make a kind of patchwork and subjective memory document that catalogues one example of this emerging cultural rite of passage. It also poses fundamental questions about the relationship of narrative to self, and memory's complicated and elusive role in the formation of both.
Freight Transport, Energy Use, and Emission Trends in Spain
Authors: Pérez-Martínez Pedro José
Published: February 2011

This study analyzes trends in freight transport, energy use, and greenhouse gas emissions in Spain from 1990 to 2007. Freight transport contributes 8.5% of Spain's greenhouse gas emissions. The emissions have experienced a 68% increase from 1990, which is 53% above the level that Spain committed to under the Kyoto Protocol; road freight made up most of the increase. Energy use will continue to grow unless there are important reductions in the energy intensities of road freight and a change in the modal share. On the basis of the most likely development of these factors, emissions will rise an additional 53% by 2025 and thereby push the sector 167% above the 1990 base year values. Emissions could be reduced 3.3% by 2025 compared with the 2007 level if the average performance of road diesel vehicles in 2025 shows a 55% increase in efficiency.
Analysis of Heavy-Duty Diesel Truck Activity and Fuel Economy Based on Electronic Control Module Data
Authors: Boriboonsomsin Kanok , Scora George , Barth Matthew
Published: February 2011

Heavy-duty diesel trucks (HDDTs) are a significant source of on-road carbon dioxide (CO2) emissions, primarily because of their low fuel economy and high annual mileage. To design strategies properly to reduce CO2 emissions from HDDTs, a good understanding of their activity and fuel economy is required. The traditional data sources and methods for quantifying HDDT activity and real-world fuel economy have limitations in one way or another. This demonstrated that the onboard electronic control module (ECM) could be another important source of data on HDDT activity and real-world fuel economy. With ECM data from 865 HDDTs, it was found that the total fuel economy was about 6.2 mpg. When adjusted for the fuel used during idle and power take-off (PTO), the driving fuel economy was 6.5 mpg. The mean idle time for this fleet was approximately 33% of the total operating hours, and the mean PTO time was about 12%. The fuel rate during idle averaged 0.6 gal/h, and the fuel rate during PTO averaged 1.3 gal/h. The average speed over the lifetime of this fleet, which included idle, was about 35 mph. When idle was excluded, the average speed of this fleet was about 53 mph. All these values are in the reasonable range.
Toward Integration of Vehicle and Fuel Regulation
Authors: Lutsey Nicholas , Sperling Daniel
Published: February 2011

Governments around the world are attempting to reduce greenhouse gas (GHG) emissions with distinct fuel and vehicle policies. As alternative powertrains and fuels are introduced, vehicle–fuel interactions become more intense and policy design and effectiveness become more problematic. These interactions are analyzed for fuel providers complying with California's Low Carbon Fuel Standard program and automakers complying with the Pavley vehicle GHG emission standards. It is found that each program could significantly affect industry compliance in the other program once both programs are implemented. This analysis, in turn, indicates that continuing coevolving adjustments will be needed to ensure that rules directed at vehicle manufacturers and fuel providers result in the most cost-effective and efficient achievement of GHG and energy goals. Specific suggestions are offered for updating and upgrading the two regulatory programs. Although the findings are specific to California, they are also broadly generalizable since many countries (including the European Union and the United States) are moving toward similar regulatory regimes.
Macroscopic Model of Greenhouse Gas Emissions for Municipalities
Authors: Derrible Sybil , Saneinejad Sheyda , Sugar Lorraine , Kennedy Christopher
Published: February 2011

In the challenge to reduce greenhouse gas (GHG) emissions from the transportation sector, urban municipalities hold significant responsibilities. The Municipal Transportation and Greenhouse Gas (MUNTAG) model was developed to help municipalities estimate their current transportation emissions, set future targets, and run forecasting scenarios and responses to policies. A set of seven criteria was adopted for the development of the model including low input, ease of use, and feasibility (i.e., the model includes only variables that are controlled by municipalities). The model contains five strategies: land use intensification, public transport, active transport, financial policies, and vehicle technology. Each use is addressed separately and then integrated into one working model. Motorized passenger kilometers traveled (PKT) per capita is first estimated with the gross domestic product per capita and population density. With transit infrastructure indicators, PKT per capita is calculated for each transit mode. Bicycle infrastructure is included to calculate the bicycle mode share. Response to several financial policies (e.g., parking price, area pricing) can be modeled by using elasticity statistics gathered from the literature. Finally, changes in vehicle technology (e.g., hybrid electric vehicles) can be modeled by adjusting the various emission factors. One advantage of the model is that all parameters can be adapted fairly easily to account for municipal specificities. Overall, it is a macroscopic, aggregate, and static model suited for medium-sized and large municipalities that can be useful as a screening tool.
Track Clearance Performance Measures for Railroad-Preempted Intersections
Authors: Brennan Thomas M. , Day Christopher M. , Sturdevant James R. , Raamot Eric M. , Bullock Darcy M.
Published: February 2011

Track clearance green phases are used at railroad-preempted intersections to provide time to clear the railroad tracks of highway vehicles before a train arrives. This paper outlines performance measures based on high-resolution, real-time traffic signal event data that can be used to assess the maximum right-of-way transfer time to track clearance green phases as well as the synchronization of the track clearance phase with the railroad gate warning system located at the crossing. These performance measures were applied to a railroad-preempted intersection over a 13-month period. Right-of-way transfer times from more than 5,002 preemption events demonstrate the importance of using automated methods for validating design assumptions for right-of-way transfer time made by traffic engineers. Track clearance performance measures tabulated over 7,648 preemptions demonstrate the need for using a longer fixed, worst-case green time for track clearance or an extensible track clearance interval that terminates when the gates descend. The parameter description on how to get gate descent information can be inferred from either the active warning-time (flashing-light signals) activation or a separate gate-down circuit. The paper concludes with recommendations for incorporating these performance measures in traffic controller firmware to address recommendations proposed in 1996 by the National Transportation Safety Board after the Fox River Grove, Illinois, railroad–grade crossing crash in 1995.
Supplementing Signalized Intersection Infrastructure to Provide Automated Performance Measures with Existing Video Detection Equipment
Authors: Smaglik Edward J. , Davis Zachary , Steele R. Christopher , Nau William , Roberts Craig A.
Published: February 2011

The objective of this work was to retrofit a signalized intersection with the goal of developing event-based performance measures while leveraging existing infrastructure to its fullest extent. A TS1 intersection managed by the Arizona Department of Transportation in Flagstaff was chosen as the test location. In addition to video from the existing cameras, video detector interface cards were installed in the cabinet to provide contact closure outputs of vehicle flow rates. These outputs were then conveyed to an onboard event-based data logger within the traffic controller via TS2 communications. Performance measures were generated [volume-to-capacity (v/c) ratio and cumulative counts] from the video-generated data and compared with manually counted data over a 24-h analysis period. The v/c values generated by the video data were shown to be statistically different from those calculated with the manual count data; however, on all but one phase, the difference was not operationally significant. Analysis of cumulative count data showed operationally significant differences. A cost analysis determined that the price of equipping a similar intersection for this type of vehicle count capability is about $16,000 if the equipment specified for this project is used and if it is installed during the construction of the intersection. It is recommended that jurisdictions interested in developing this type of flow information consider equipping future intersections in a similar manner and that future work be completed in the evaluation of the use of video detection units for flow rate collection at signalized intersections.
Decision Tree Model to Prioritize Signalized Intersections near Highway–Railroad Crossings for Railroad Interconnect
Authors: Brennan Thomas M. , Hulme Eric A. , Day Christopher M. , Sturdevant James R. , Overman Tim , Kruger Jessica , Bullock Darcy M.
Published: February 2011

The Manual on Uniform Traffic Control Devices provides a list of factors to be considered when an agency is determining whether a highway–railroad crossing located farther than 200 ft from a signalized intersection should have a railroad-preempted interconnection or be provided with alternative queue management methods. One such factor is the estimated queue length between the signalized intersection and the railroad crossing. Currently, no systematic assessment procedure both (a) quantitatively prioritizes intersections near railroad crossings on the basis of their potential to queue vehicles over the tracks and (b) is reasonably quick to apply agencywide. This paper proposes a decision tree procedure for screening and prioritizing traffic signals near highway–railroad crossings on the basis of estimated queue lengths. An integral component of this procedure is the concept of queue margin, calculated as the difference between (a) clear storage distance between the track and the stop bar and (b) the estimated length of queue traffic. This prioritization procedure was applied to 595 traffic signals in northwest Indiana to prioritize and rank the top 20 intersections for more detailed site investigation. Example intersections are used to illustrate higher-fidelity data collection and queue management strategies.
Framework for Evaluating Advance-Detection Designs for High-Speed Intersection Approaches
Authors: Pratt Michael P. , Bonneson James A.
Published: February 2011

This paper describes a framework for evaluating an advance-detection design. The framework can be used to identify the most effective configurations for a given detection design. It accounts for the detection layout, including number and position of detectors; traffic conditions, including volume and speed; and controller settings, including passage time and operation of the stop line detector after queue clearance. The framework is demonstrated by application to six advance-detection designs used in Texas. The framework is based on measures of control delay, probability of ending the green phase through max-out, and probability of providing indecision-zone protection during green-phase gap-out. The latter measure is defined as “detection coverage.” These measures are useful for quantifying the operational and safety performance of a detection design. The framework can be used (a) to select an advance-detection design for an intersection approach with a given 85th percentile traffic speed and (b) to determine the range of traffic speeds for which the detection design can provide acceptable indecision-zone coverage. This information is useful for sites where traffic speeds are not known precisely or are expected to vary over the day, week, or month. It can also be used to determine how changes in controller settings will affect the performance of the detection design.
Cross-Evaluation of Signal Timing Optimized by Various Traffic Simulation and Signal Optimization Tools
Authors: Mulandi James , Stevanovic Aleksandar , Martin Peter T.
Published: February 2011

The most popular tools for traffic simulation and signal timing optimization are macroscopic and deterministic in structure. Microscopic tools are also available and are gaining popularity because they simulate the stochastic nature of traffic flow. Performance of the optimized signal timing developed by any tool depends on the fidelity of the traffic models embedded in it. This study evaluates the performance of signal timing developed by the most popular signal-timing optimization tools. It examines signal timing from each tool in various macroscopic and microscopic simulation environments and includes statistical tests to find which tool produces signal timing of the highest quality. Each of the four tools selected (two macroscopic and two microscopic) can both optimize and evaluate signal timing. A real-world arterial with 12 signalized intersections serves as the test bed. To eliminate skewness and bias in the results, all experiments were performed under the same geometric and traffic characteristics in each tool. Saturation flow rates from each calibrated model were assessed to ensure that all the tools processed traffic demand consistently. The results indicate that, overall, VISSIM-based genetic algorithm optimization of signal timing and the Synchro programs produce signal timing of the highest quality and provide extremely similar performance.
Arterial Performance Measures with Media Access Control Readers
Authors: Quayle Shaun M. , Koonce Peter , Depencier Darryl , Bullock Darcy M.
Published: February 2011

This study reports on the use of media access control (MAC) readers through the Bluetooth protocol by means of off-the-shelf equipment to measure arterial travel performance (segment travel time, average running speed, and origin–destination). First, the MAC reader technology was deployed at the same time that travel time runs by the traditional floating-car method were used to evaluate the general reliability and accuracy of the MAC technology. Second, the MAC reader technology was used to track before-and-after changes to signal timing along the corridor to measure the effectiveness of the adjustments, proving its real-world applicability while requiring far fewer resources than traditional data collection means. A comparison of the Bluetooth MAC address data with traditional Global Positioning System floating-car studies suggests that the larger data set from the Bluetooth data more effectively captures performance characteristics of the arterial. The research was conducted on a 2.5-mi suburban signalized arterial in Portland, Oregon, over 27 days. The paper concludes by discussing the system architecture for a permanent real-time deployment and other areas for future research. The real-time MAC reader information provides substantial opportunity to add new control and performance monitoring capability to other intelligent transportation system components, such as ramp metering, transit signal priority systems, and adaptive signal control.
Short-Term Traffic Forecast System of Beijing
Authors: Dong Shen , Li Ruimin , Sun Li Guang , Chang Tang Hsien , Lu Huapu
Published: February 2011

A short-term, real-time system was developed to support traffic management in Beijing. The requirements of a large amount of data and unstable traffic flow are the biggest challenges to such a system. The models and software framework thus should be effective enough to face these problems. The core of such a system is the short-term traffic flow forecast model. Rapid urbanization and transportation development in Beijing have led to traffic flow patterns with some unstable characteristics. The short-term forecast model for an online system thus was designed with the fast-paced trend in mind. The model considers historical data, real-time data, and space data, and it can be updated online. Thus a combined model was developed with three submodels: discrete Fourier transform model, autoregressive model, and neighborhood regression model. Weights of each submodel were based on forecast error. Both the historical forecast error and real-time forecast error were considered. The system was built on a browser–server structure to support combined forecast models. The framework, modules, and interface of this system are introduced in this paper.
Freeway Truck Lane Restriction and Differential Speed Limits
Authors: Korkut Murat , Ishak Sherif , Wolshon Brian
Published: February 2011

Over the past decade, several fatal truck-related crashes have occurred on the elevated freeway over the Atchafalaya Basin segment of Interstate 10 in southern Louisiana. In an attempt to reduce the crash rates, the Louisiana Department of Transportation and Development has implemented two policies to regulate the truck traffic on this rural section of freeway. These policies restrict truck traffic to the right lane and reduce the maximum truck speed limit to 55 mph while maintaining passenger car speed limits at 60 mph. To investigate potential relationships between compliance with these policies and crash rates, traffic and crash data were collected for the segment while the policies were in force. Relationships between hourly observations of crash rates and compliance rates were sought at the .05 significance level with multiple linear regression. The traffic characteristics that might affect such a relationship were also incorporated into the regression models. These characteristics included difference between truck and car speeds, speed variance, truck volume, and lane occupancy. The regression models were performed with SAS software. Confidence intervals on the means of the explanatory variables were constructed to understand the variability in the values of the traffic characteristics over different days of the data collection period. The results showed that violation of the lane restriction and truck speed limits, truck speed variance, differences between car and truck mean speeds, and lane occupancy were positively correlated with crash rates. The findings suggested that prohibiting trucks from traveling in the left lane and setting a truck speed limit of 55 mph and a car speed limit of 60 mph on a four-lane elevated rural freeway can offer traffic safety benefits.
Survey of Novice Motorcycle Riders and Their Riding Experience before Licensing
Authors: De Rome Liz , Ivers Rebecca , Haworth Narelle , Heritier Stephane , Fitzharris Michael , Du Wei
Published: February 2011

Graduated licensing schemes have been found to reduce the crash risk of young novice drivers, but there is less evidence of their success with novice motorcycle riders. This study examined the riding experience of a sample of Australian learner–riders to establish the extent and variety of their riding practice during the learner stage. Riders completed an anonymous questionnaire at a compulsory rider-training course for the licensing test. The majority of participants were male (81%) with an average age of 33 years. They worked full time (81%), held an unrestricted driver's license (81%), and owned the motorcycle that they rode (79%). These riders had held their learner's license for an average of 6 months. On average, they rode 6.4 h/week. By the time they attempted the rider-licensing test, they had ridden a total of 101 h. Their total hours of on-road practice were comparable to those of learner–drivers at the same stage of licensing, but they had less experience in adverse or challenging road conditions. A substantial proportion had little or no experience of riding in the rain (57%), at night (36%), in heavy traffic (22%), on winding rural roads (52%), or on high-speed roads (51%). These findings highlight the differences in the learning processes between unsupervised novice motorcycle riders and supervised novice drivers. Further research is necessary to clarify whether specifying the conditions under which riders should practice during the graduated licensing process would likely reduce or increase their crash risk.
Right-Angle Crash Vulnerability of Motorcycles at Signalized Intersections
Authors: Haque M. Mazharul , Chin Hoong Chor
Published: February 2011

Motorcycles are particularly vulnerable in right-angle crashes at signalized intersections. The objective of this study is to explore how variations in roadway characteristics, environmental factors, traffic factors, maneuver types, human factors, and driver demographics influence the right-angle crash vulnerability of motorcycles at intersections. The problem is modeled by using a mixed logit model with a binary choice category formulation to differentiate how an at-fault vehicle collides with a not-at-fault motorcycle in comparison with other collision types. The mixed logit formulation allows randomness in the parameters and hence takes into account the underlying heterogeneities potentially inherent in driver behavior and other unobserved variables. A likelihood ratio test reveals that the mixed logit model is indeed better than the standard logit model. Nighttime riding shows a positive association with the vulnerability of motorcyclists. Moreover, motorcyclists are particularly vulnerable on single-lane roads, on the curb and median lanes of multilane roads, and on one-way and two-way roads relative to divided highways. Drivers who deliberately run red lights and those who are careless toward motorcyclists, especially when turning at intersections, increase the vulnerability of motorcyclists. Drivers appear more restrained when there is a passenger onboard, and this factor has decreased the crash potential for motorcyclists. The presence of red light cameras also significantly decreases right-angle crash vulnerabilities of motorcyclists. The findings of this study would be helpful in developing more targeted countermeasures for traffic enforcement, driver or rider training or education, and safety awareness programs to reduce the vulnerability of motorcyclists.
Review of Parking Design Practices for Motorcycles
Authors: Cottrell Wayne D.
Published: February 2011

Motorcycle parking design practices in the United States and abroad are investigated. Numerous agencies and jurisdictions have developed codes and policies on stall and bay dimensions, motorcycle-to-automobile parking space ratios, parking demand rates as a function of land use, and motorcycle–automobile equivalence factors, but the values in use lack consistency. This paper suggests that stall dimensions be based on regional assessments of the sizes of motorcycles being driven. The number of motorcycle parking spaces provided should be developed from demand surrogates, such as total motorcycle registrations and motorcycle registrations as a percentage of noncommercial vehicle registrations. The following are recommended when motorcycle size data are not available: a 5-ft (1.5-m; alternatively 7.5-ft or 2.3-m for the disabled) × 8.2-ft (2.5-m) stall and 60° parking angle (90° in low-traffic environments). The development of uniform motorcycle parking signs should be considered, to inform motorcyclists of legal parking locations. The installation of rails, hoops, or posts adjacent to parking stalls for motorcycle security is also recommended.