Decomposition of SU(N) connection and Effective Theory of SU(N) QCD

We give a general decomposition of SU(N) connection and derive a generalized Skyrme-Faddeev action as the effective action of SU(N) QCD in the low energy limit. The result is obtained by separating the topological degrees which describes the non-Abelian monopoles from the dynamical degree of gauge potential, and integrating all the dynamical degrees of SU(N) QCD.Comment: retex, 7 page

Surrogate measures for evaluating new signage and intersection designs

Transportation agencies faced with the challenge of enhancing safety on roadways are looking for alternative solutions to designing roads and signage. When deciding whether the alternative design is superior to the traditional one, decision makers need methods and quantitative data to evaluate these alternatives. This dissertation provides two accessible methods to compare different alternative designs and illustrates them using case studies. The first method involves using speed-based statistical measures that are extracted from video-based traffic surveillance. This method was more accurate in collecting vehicle speeds than the speeds extracted from video-based data collection systems. It was then utilized to evaluate the effectiveness of an alternative merge sign in work zones. This alternative sign consists of an arrow pointing the merge direction and text describing the lane closure, while MUTCD sign is graphical. The case study measured driver behavior characteristics including speeds and open lane occupancies. The results indicate that open lane occupancy was higher for the test sign in comparison to the MUTCD sign upstream of the merge sign. The occupancy values at different distances between the merge sign and the taper were similar for both the test and MUTCD signs, but the test sign encouraged up to 11% more cars to be in the open lane immediately upstream of the merge sign. Passenger cars stayed in the closed lane longer, or closer to the taper, than trucks. The merging behavior of truck drivers did not vary significantly with the type of merge sign deployed in the work zone. The analysis of speed characteristics did not reveal substantial differences between the two sign configurations. The mean speeds with the MUTCD configuration were 1.3 mph and 2 mph lower than the test configuration at the merge sign and taper locations, respectively. The second method utilizes microscopic traffic simulation to evaluate alternative designs. This method is ideal for projects where video monitoring of the entire study of interest is not feasible. Evaluating alternative designs with crash data usually requires a long time span to build the facility and record crash data over at least one year after the facility has been open to traffic. In addition to that, new facility needs to be built or altered if other design features are to be tested. With microscopic simulation, the time cost for the study is greatly shortened and different design aspects can be tested in a risk-free environment. Two case studies are presented to illustrate this simulation method. The first case study involves a work zone while the second case study focuses on evaluating a J-turn intersection design. The spacing of U-turn and the inclusion of acceleration and deceleration lanes were evaluated, in the J-turn study. A simulation analysis was conducted to study the impact of different design variables on the safety of J-turns. A base simulation model was created and calibrated using field data collected in a previous Missouri Department of Transportation (MoDOT) project on J-turns. The calibrated model was then used to study various combinations of major road and minor road volumes and design variables. The simulation analysis helped develop guidance on recommended spacing for various major road and minor road volume scenarios. For all the studied scenarios, the presence of acceleration lane resulted in significantly fewer conflicts. Thus, acceleration lanes are recommended for all J-turn designs, including lower volume sites. Second, while U-turn spacing between 1000 feet and 2000 feet was found to be sufficient for low volume combinations, a spacing of at least 1500 feet and 2000 feet are recommended for medium and high volumes, respectively

Evaluation of temporary ramp metering for work zone safety

Title from PDF of title page; abstract from research PDF (University of Missouri--Columbia, viewed on June 26, 2014).Ramp metering has been successfully implemented in many states and studies have documented its positive mobility and safety benefits. However, there have been no studies on the use of ramp metering for work zones. This thesis reports the results from the first deployment of temporary ramp meters in work zones in the United States. Temporary ramp meters were deployed at seven work zones in Missouri. Due to lack of crash data, this study uses video data to extract alternative safety measures such as driver compliance, merging behavior, speed differentials, lane changing, and braking maneuvers. This evaluation suggests that temporary ramp meters should only be deployed at work zone locations where there is potential for congestion and turned on only during periods of high congestion. In comparison to over 90% compliance rates of permanent ramp meters implemented in other states, field data showed compliance rates from 40.5% to 82.9% in temporary ramp meter. This suggested that non-compliance could be a major safety issue in the deployment of temporary ramp meters. The use of a three-section instead of a traditional two-section signal head used for ramp metering produced significantly higher compliance rates. This thesis then aggregated the data into groups to further analyze the effects of different factors such as platoons, commercial trucks, work zone type and work zone-ramp configuration. After analyzing general characteristics of mainline and ramp vehicle speed and speed differentials, this study then focused on findings for different comparison groups. The two comparison groups are "between two work zones" versus "before work zone" configuration and "left-lane closed" versus "right-lane closed" work zone type. Results indicated lower mean speeds of mainline and ramp vehicles and higher differentials when ramp metering was turned on. This is expected and again temporary ramp meters are recommended only where congestion occurs. Congestion will lead to lower mainline speeds thus lower speed differentials either with or without ramp metering. Finally, analysis of merging headways showed that temporary ramp meters were effective in separating platoons before vehicles merged into mainline. This produces more single-vehicle merging which requires shorter gaps and causes fewer impacts on the mainline traffic

A Calibration Method for Wide Field Multicolor Photometric System

The purpose of this paper is to present a method to self-calibrate the spectral energy distribution (SED) of objects in a survey based on the fitting of an SED library to the observed multi-color photometry. We adopt for illustrative purposes the Vilnius (Strizyz and Sviderskiene 1972) and Gunn & Stryker (1983) SED libraries. The self-calibration technique can improve the quality of observations which are not taken under perfectly photometric conditions. The more passbands used for the photometry, the better the results. This technique has been applied to the BATC 15-passband CCD survey.Comment: LateX file, 1 PS file, submitted to PASP number 99-025 The English has been improved and some mistakes have been correcte

Calibration of Highway Safety Manual Work Zone Crash Modification Factors

The Highway Safety Manual is the national safety manual that provides quantitative methods for analyzing highway safety. The HSM presents crash modification factors related to work zone characteristics such as work zone duration and length. These crash modification factors were based on high-impact work zones in California. Therefore there was a need to use work zone and safety data from the Midwest to calibrate these crash modification factors for use in the Midwest. Almost 11,000 Missouri freeway work zones were analyzed to derive a representative and stratified sample of 162 work zones. The 162 work zones was more than four times the number of work zones used in the HSM. This dataset was used for modeling and testing crash modification factors applicable to the Midwest. The dataset contained work zones ranging from 0.76 mile to 9.24 miles and with durations from 16 days to 590 days. A combined fatal/injury/non-injury model produced a R2 fit of 0.9079 and a prediction slope of 0.963. The resulting crash modification factors of 1.01 for duration and 0.58 for length were smaller than the values in the HSM. Two practical application examples illustrate the use of the crash modification factors for comparing alternate work zone setups

Investigation of Alternative Work Zone Merging Sign Configurations

This study investigated the effect of an alternative merge sign configuration within a freeway work zone. In this alternative configuration, the graphical lane closed sign from the MUTCD was compared with a MERGE/arrow sign on one side and a RIGHT LANE CLOSED sign on the other side. The study measured driver behavior characteristics including speeds and open lane occupancies. The measurements were taken at two identical work zones on I-70 in Missouri, one with the new test sign and the other with the standard MUTCD sign. The study found that the open lane occupancy upstream of the merge sign was higher for the test sign in comparison to the MUTCD sign. Occupancy values at different distances between the merge sign and the taper were similar for both signs. The test sign had 11% more traffic in the open lane upstream of the merge sign. In terms of safety, it is desirable for vehicles to occupy the open lane as far upstream from the taper as possible to avoid conflicts due to the lane drop. Thus, the test sign proved to be a good alternative to the MUTCD sign. The analysis of speed characteristics did not reveal substantial differences between the two sign configurations. The 85th percentile speeds with the MUTCD sign were 1 mph and 2 mph lower than the test sign at the merge sign and taper locations, respectively

Regional Heterogeneity of Perivascular Adipose Tissue: Morphology, Origin, and Secretome

Perivascular adipose tissue (PVAT) is a unique fat depot with local and systemic impacts. PVATs are anatomically, developmentally, and functionally different from classical adipose tissues and they are also different from each other. PVAT adipocytes originate from different progenitors and precursors. They can produce and secrete a wide range of autocrine and paracrine factors, many of which are vasoactive modulators. In the context of obesity-associated low-grade inflammation, these phenotypic and functional differences become more evident. In this review, we focus on the recent findings of PVAT’s heterogeneity by comparing commonly studied adipose tissues around the thoracic aorta (tPVAT), abdominal aorta (aPVAT), and mesenteric artery (mPVAT). Distinct origins and developmental trajectory of PVAT adipocyte potentially contribute to regional heterogeneity. Regional differences also exist in ways how PVAT communicates with its neighboring vasculature by producing specific adipokines, vascular tone regulators, and extracellular vesicles in a given microenvironment. These insights may inspire new therapeutic strategies targeting the PVAT