725 research outputs found
Emerging market chrises : an asset markets perspective
No full textAdditional author listed in caption title on p. 1: Arvind KrishnamurthyOctober, 1998--t.p. -- This draft: Novebmer 5, 1998--P.
Performance Analysis of Squad Car Lighting, Retro-reflective Markings, and Paint Treatments to Improve Safety at Roadside Traffic Stops
No full textIn the United States, more police officers are killed in collisions at roadside stops than through felonious acts. Causal factors that affect police safety at roadside stops include officer conspicuity, squad conspicuity, weather conditions, and the attention and fatigue level of the traveling public. Described herein is a research project that provides insight and guidelines that may ultimately improve officer safety at roadside stops. The project is designed to modify an existing sensor-based traffic monitoring system so that it serves as a test bed to evaluate the retro-reflector, lighting, and paint treatments of an emergency vehicle to determine whether particular combinations produce improved “move over” behavior of oncoming traffic. This is done using automated data analysis software built specifically for this project. Tests are performed at a fully instrumented rural intersection. After mimicking a traffic stop where a patrol vehicle is placed at this intersection, the experimenter logs onto a website and enters the time when the test took place. Analysis software draws results from the data. The results are e-mailed to the experimenters, who devise their own test regimes, following the guidelines presented herein, and draw their own conclusions. A second system was built to provide a more portable option for testing in urban areas. This system consists of two freestanding radar boxes with wireless communication, as well as one netbook computer. Test procedures and results are analogous to the original system. Additional calibration is automatically performed to account for the variable position of the radars.Intelligent Vehicles Laboratory, Department of Mechanical Engineering, University of MinnesotaFischer, Jacob; Krzmarzick, Adam; Menon, Arvind; Shankwitz, Craig. (2012). Performance Analysis of Squad Car Lighting, Retro-reflective Markings, and Paint Treatments to Improve Safety at Roadside Traffic Stops. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/148679
Minnesota Department of Transportation Rural Intersection Conflict Warning System (RICWS) Reliability Evaluation
No full textThe Minnesota Department of Transportation (MnDOT) developed the Rural Intersection Conflict Warning System (RICWS) Deployment project to reduce crashes at stop-controlled intersections. It is a statewide, Intelligent Transportation Systems project that will deploy intersection conflict warning systems at up to 50 rural, stop-controlled intersections. These systems will address crashes at stop-controlled intersections by providing drivers - on both the major and minor road - with a dynamic warning of other vehicles approaching the intersection. The first RICWS site, Trunk Highway 7 and Carver County CSAH 33, was evaluated for a period of 34 days to demonstrate the reliability of the system. During this period, the RICWS signs, beacons, and any other displays were covered and unavailable for driver interaction. The University of Minnesota installed a portable Intersection Surveillance System (ISS) and collected data from the RICWS as well as from the ISS. The data collected from the RICWS was validated against data recorded by the ISS in order to determine the accuracy and reliability of the RICWS. The RICWS was determined to have an activation rate of 99.98%, and meets the MnDOT specification of 99.95% sign activation rate. Sign activations were also validated using video captured at the site and a sample of times for valid activations and valid periods when the sign was inactive were recorded.Menon, Arvind; Donath, Max. (2014). Minnesota Department of Transportation Rural Intersection Conflict Warning System (RICWS) Reliability Evaluation. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/164687
Cultural Spectrum in Arvind Adiga’s Selection Days
No full textCultural Studies have played a pivotal role in understanding and evaluating the power dynamics of the social, political, economic and ethical world order by empirically engaging and focusing on the present-day culture, tracing its historical roots and explicating its attributes with reference to a particular literary text and its reception in a society. Arvind Adiga, the Man-Booker Prize winning Indo-Australian author, in Selection Day, has adroitly detailed how cricket as an individual entity impacts the cultural phenomena of a society by confronting its inherent myriad issues. The narrative delves deep into the lives of two siblings - Radha and Manju, witnesses the dramatic turnaround of events and tries to capture the themes of unfulfilled desires and preordained destinies. The novel also explores how the sport holds different meanings and significance for different characters, each of whom view the game in the light of their own ideology. The author foresees and sensitizes the theme of homosexuality, which is still a taboo and been unheard of, within the sports fraternity. Adiga’s critique of the parental felony, embodied in Mohan Kumar, and its repercussions is the most compelling theme at the heart of this work of fiction. Selection Day powerfully binds together the societal phenomena of class construction, unquenchable thirst for money, sexual orientations and ideologies with a single thread and studies how culture, in itself, is an ever-evolving phenomenon
Technology Enabling Near-Term Nationwide Implementation of Distance Based Road User Fees
No full textThis report describes a system meant for near-term deployment that directly determines the distance traveled by a vehicle and uses this as a basis for charging a fee that reflects road use. An in-vehicle device with access to the vehicle data bus and power through a single standard connector available on all passenger vehicles since 1996, electronically calculates the distance and then securely communicates relevant information to a “back office” for processing and transferring accumulated fees from the user to the appropriate government jurisdiction. Also described are means for providing payment (and receiving credit for motor fuel use taxes paid at the pump) while also ensuring compliance, enforcement, transparency and privacy. Communication is via text messaging, available wherever cellular service is accessible. No new wireless infrastructure is needed. The in-vehicle device distinguishes distance traveled by state or by other regions of interest e.g., rural vs. urban areas, using the same cellular technology that is used for communications. Aggregating distance based on rural vs. urban travel can facilitate different pricing policies for these different road users. Neither a GPS receiver nor longitude/latitude position data is necessary. However, higher resolution position sensing can be added to the core platform as needed based on policy objectives, e.g., to consider alternate pricing for specific road facilities.Donath, Max; Gorjestani, Alec; Shankwitz, Craig; Hoglund, Richard; Arpin, Eddie; Cheng, PiMing; Menon, Arvind; Newstrom, Bryan. (2009). Technology Enabling Near-Term Nationwide Implementation of Distance Based Road User Fees. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/97660
Antecedents and Enablers of Green Supply Chain Practices
No full textThe thesis titled antecedents and enablers of green supply chain practices focuses on one of the most contemporary issues in supply chain management. The literature review explores the existing literature and research work on green supply chain practices and develops a framework for the research. The research is qualitative in nature and data was collected from the three automobile component-manufacturing companies in India. Semi structured interviews were conducted over a period of 18 months.
There were three objectives for this thesis:
1. Describing the current state of green supply chain practices?
2. What are the antecedents and enablers for green supply chain practices?
3. What are the underlying mechanisms, if any?
The research work concludes by answering all the above three questions and also gives the future direction for research. The research work started by finding a gap for the empirical research in the context of green supply chain practices. The objective of the research was to focus on antecedents and enablers of green supply chain practices. Some contextual factors, inhibitors and consequences are also emerged during the pilot case study.
The research work is rigor and to ensure the rigor of the research design, five-stage process was used to structure the methodology. As a final check author assessed his research against the four basic tests commonly used in empirical research; construct validity, internal validity, external validity and reliability. The research study has contributed both to the development and testing of theory relating to the antecedents and enablers of green supply chain practices. The review of literature provided a synthesis of the underpinning bodies of literature that has not previously been conducted in this way. This resulted in the identification of ten core green supply chain practices for the development of antecedents and enablers that created the foundation for author’s empirical investigation. It was found that previous studies have been largely theoretical. The empirical studies that do exist have focused on one particular dyadic relationship with in green supply chain practices.
A double contribution has been made to testing the theory of green supply chain practices from a process and output perspective. As process perspective, a contribution has been made to methodology by developing a robust approach for conducting supply chain research beyond the dyad. From output perspective, the author has the empirical results from the three individual case studies and their cross-case comparison for dissemination to an academic audience.
Specific contribution of this research to theory development include:
1. Development of macro model of green supply chain practices with the inputs from literature.
2. The synthesis of ten core green supply chain practices with antecedents and enablers from existing body of literature enriched through empirical testing
3. Empirical derivation of three contextual factors.
Although the research work is new and contribute to the theory and practices, there are still some limitations of this research. Two minor limitations have been identified:
1. Generalizability of result to practice to practice: Due to the limited size of the case study approach, the results can only be generalized to theory and not to practice.
2. Variation in quality of information: The scope of data collection for all three case studies was same still the quality of information gathered was different. As good quality cross-case analysis was still possible but the relative strengths of the three cases varied.
Overall the research work is original, rigor, and contributes to the existing theory and also paves the path for future research work in the area of green supply chain practices
The Design of a Minimal Sensor Configuration for a Cooperative Intersection Collision Avoidance System - Stop Sign Assist: CICAS-SSA Report #2
No full textThe deployment of a Cooperative Intersection Collision Avoidance System – Stop Sign Assist (CICAS-SSA) can save lives by addressing the causal factor of crashes at rural thru-Stop intersection: drivers who stop on the minor leg of the intersection, improperly assess the gaps in the traffic on the major leg, proceed, and are then hit. The prototype CICAS-SSA system consisted of a network of sensors covering both the minor and the major legs of the intersection. Sensors on the minor road monitored the approach of vehicles and classified them based on their length and height. Sensors along the major road were arrayed to track vehicles (and the gaps between them) approaching the crossroads from 2000 feet away as a means to ensure that the tracking algorithm had sufficient time to “lock on” and track all approaching vehicles. Because cost is a primary concern for any highway safety application, the development of a “minimal sensor set” which would provide adequate safety performance for minimum cost was paramount to the success of the CICAS-SSA program. This report documents the development of this minimal sensor configuration.Gorjestani, Alec; Menon, Arvind; Cheng, Pi-Ming; Shankwitz, Craig; Donath, Max. (2010). The Design of a Minimal Sensor Configuration for a Cooperative Intersection Collision Avoidance System - Stop Sign Assist: CICAS-SSA Report #2. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/101438
A Numerical Investigation of Aerodynamically Trapped Vortex Combustor for Premixed Hydrogen Combustion in Gas Turbines Using Detailed Chemistry
No full textHydrogen is a clean and carbon-free fuel and is considered a key element for the energy transition. Renewable power generation by solar and wind is increasing, requiring flexible operation to balance the load on the energy grid with the ability to rapidly adjust the output. Gas turbines with a combustion system for hydrogen operation offers a low carbon solution to support the stability of the energy grid. This provides a solution capturing the needs for energy storage, in the form of hydrogen, and flexible power generation. High flame temperatures in the primary zone facilitates the production of NOx which can be reduced by using premixed combustors. But this introduces the risk of flame flashback. Several combustor concepts have been proposed and studied in the past few years to tackle the problem of flame flashback in premixed high hydrogen fuel combustors. This study looks at one of the concepts which uses Aerodynamically Trapped Vortex to stabilize the flame and studies the flow and flame behavior in the combustor. Numerical simulations for the analysis were performed with commercial Computational Fluid Dynamics (CFD) simulation package AVL FIRE™. The flow field characterization was focused on the investigation of the influence of the inlet velocity and inlet turbulence intensity (u′) on the mean velocity, wall velocity gradient and turbulence intensity in the combustor. To study the flame stabilization mechanism, reactive simulations were performed at two fuel equivalence ratios. The combustion regime of the flame, wall velocity gradient and temperature distribution in the combustor were quantified from the simulation results. A validation study was performed prior to the analysis of the ATV combustor to validate both the turbulence and the reactive models for premixed hydrogen combustion. The models were validated against the experiments performed in a dump stabilized cylindrical combustor at Combustion Research Laboratory, Paul Scherrer Institute (PSI), Switzerland. The k-ε and k-ζ-f turbulence models were selected for modelling the turbulence. Simulations of non-reacting flow with k-ε model resulted in a more accurate prediction of the flow field, turbulence levels and recirculation zone than the k-ζ-f model. Combustion is modelled using the FIRE™ detailed chemistry solver with the k-ε turbulence model to resolve turbulence. No additional turbulence-chemistry interaction model is used in the current research. To reduce chemistry computational time, the multi-zone method is employed. A detailed chemistry approach with sufficient mesh resolution for modelling the reaction in 100% premixed hydrogen combustion predicted the flame behavior with acceptable accuracy. The flow analysis in the Aerodynamically Trapped Vortex (ATV) combustor revealed that the inlet velocity or inlet turbulence had no significant effect on the relative turbulence properties in the flame stabilization zone. The proposed design for the Aerodynamically Trapped Vortex (ATV) combustor was able to stabilize a 100% premixed hydrogen flames without flashback for the simulated conditions.Aerospace Engineerin
Trade policies and trade mis-reporting in Myanmar
No full textWhile the trade statistics of Myanmar show surpluses for 2007 through 2010, the corresponding statistics of trade partner countries indicate deficits. Such discrepancies in mirror trade statistics are analyzed in connection with the ‘export-first and import-second’ policy provisioning import permissions on permission applicants possessing a sufficient amount of the export-tax-deducted export earnings. Under this policy, the recorded imports and exports of the private sector have been maintaining equilibrium, whereas discrepancies in the mirror statistics have fluctuated. This suggests that traders adjusted mis-reporting in accordance with the supply and demand of the export earnings.Myanmar, Trade policy, Trade problem, Trade Policies, Mis-invoicing, Smuggling
Intersection Decision Support Surveillance System: Design, Performance and Initial Driver Behavior Quantization
No full textIn rural Minnesota, approximately one-third of all crashes occur at intersections. Analysis of crash statistics and reports of crashes at rural expressway through-stop intersections shows that, for drivers who stop before entering the intersection, the majority of crashes involve an error in selecting a safe gap in traffic. The Intersection Decision Support system, developed at the University of Minnesota, is intended to reduce the number of driver errors by providing better information about oncoming traffic to drivers stopped at intersections.
This report deals primarily with the surveillance technology which serves as the foundation upon which the IDS system will be built. Three components of the surveillance system are described in detail in the body of the report: 1) a Mainline Sensor subsystem; 2) a Minor Road Sensor subsystem; 3) a Median Sensor subsystem. These subsystems include radar units, laser-scanning sensors, and infrared cameras, integrated with a vehicle tracking and classification unit that estimates the states of all vehicles approaching the intersection. The design, installation, performance, and reliability of each of these three subsystems are documented in the report.
The report concludes with an analysis of driver gap acceptance behavior at an instrumented intersection. Gap selection is examined as a function of time of day, traffic levels, weather conditions, maneuver, and other parameters. Log-normal distributions describe gaps acceptance behavior at rural, unsignalized expressway intersections.Minnesota Department of TransportationAlexander, Lee; Cheng, Pi-Ming; Donath, Max; Gorjestani, Alec; Menon, Arvind; Shankwitz, Craig. (2007). Intersection Decision Support Surveillance System: Design, Performance and Initial Driver Behavior Quantization. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/5584
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