9 research outputs found
A novel RGBW pixel for LED displays
In this work, a novel pixel configuration RGBW, consisting of red (R), green (G), blue (B), and white (W) LEDs, is employed and investigated for color generation. Energy consumption and various hues of new pixels are compared to standard pixels consisting of RGB LEDs. Human perception experiments are conducted in order to study the perceptual difference between the two architectures when the same colors are generated using RGBW vs. RGB. Power measurements for an 8x8 pixel LED display has demonstrated up to 49% power savings for gray scale, over 30% power savings for low saturated colors, and up to 12% for high saturated colors using RGBW as an alternative. Furthermore, human perception studies has shown that vast majority of test subjects could not distinguish between most colors displayed using RGB and RGBW showing that RGBW is an excellent substitute for RGB. Statistics has shown that 44% of test subjects found the colors in gray scale to be the same, whereas 82% and 95% of test subject found low saturated colors and high saturated colors, respectively, to be identical
Cyber physical complex networks, modeling, analysis, and control
This research scrutinize various attributes of complex networks; mainly, modeling, sensing, estimation, safety analysis, and control. In this study, formal languages and finite automata are used for modeling incident management processes. Safety properties are checked in order to verify the system. This method introduces a systematic approach to incident management protocols that are governed by mostly unsystematic algorithms. A portion of the used data in this study is collected by means of radar and loop detectors. A weighted t-statistics methodology is developed in order to validate these detectors. The detector data is then used to extract travel time information where travel time reliability is investigated. Classical reliability measures are examined and compared with the new entropy based reliability measure proposed in this study. The novel entropy based reliability measure introduces a more consistent measure with the classical definition of travel time reliability than traditional measures. Furthermore, it measures uncertainty directly using the full distribution of the examined random variable where previously developed reliability measures only use first and second moments. Various approaches of measuring network reliability are also investigated in this study. Finally, feedback linearization control scheme is developed for a ramp meter that is modeled using Godunov\u27s conditions at the boundaries representing a switched system. This study demonstrates the advantages of implementing a feedback liberalized control scheme with recursive real time parameter estimation over the commonly practiced velocity based thresholds
Energy Efficient RGBW Pixel Configuration for Light-emitting Displays
A study on LED displays has been conducted exploring a more efficient method for color generation than the traditional method. The study is comprehensive and thoroughly performed employing various sets of experiments in order to examine the functionality of the new proposed scheme which includes a literature review, theoretical modeling based on a scientific study, experimental data measurements of a developed prototype, and statistical data based on a survey. This study resulted in very interesting outcomes that may lead to a tremendous change in the existing LED display technology
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Photonics Research and Development
During the period August 2005 through October 2009, the UNLV Research Foundation (UNLVRF), a non-profit affiliate of the University of Nevada, Las Vegas (UNLV), in collaboration with UNLVâs Colleges of Science and Engineering; Boston University (BU); Oak Ridge National Laboratory (ORNL); and Sunlight Direct, LLC, has managed and conducted a diverse and comprehensive research and development program focused on light-emitting diode (LED) technologies that provide significantly improved characteristics for lighting and display applications. This final technical report provides detailed information on the nature of the tasks, the results of the research, and the deliverables. It is estimated that about five percent of the energy used in the nation is for lighting homes, buildings and streets, accounting for some 25 percent of the average homeâs electric bill. However, the figure is significantly higher for the commercial sector. About 60 percent of the electricity for businesses is for lighting. Thus replacement of current lighting with solid-state lighting technology has the potential to significantly reduce this nationâs energy consumption â by some estimates, possibly as high as 20%. The primary objective of this multi-year R&D project has been to develop and advance lighting technologies to improve national energy conversion efficiencies; reduce heat load; and significantly lower the cost of conventional lighting technologies. The UNLVRF and its partners have specifically focused these talents on (1) improving LED technologies; (2) optimizing hybrid solar lighting, a technology which potentially offers the benefits of blending natural with artificial lighting systems, thus improving energy efficiency; and (3) building a comprehensive academic infrastructure within UNLV which concentrates on photonics R&D. Task researchers have reported impressive progress in (1) the development of quantum dot laser emitting diodes (QDLEDs) which will ultimately improve energy efficiency and lower costs for display and lighting applications (UNLV College of Engineering); (2) advancing green LED technology based on the Indium-Gallium-Nitride system (BU), thus improving conversion efficiencies; (3) employing unique state-of-the-art X-ray, electron and optical spectroscopies with microscopic techniques to learn more about the electronic structure of materials and contacts in LED devices (UNLV College of Science); (4) establishing a UNLV Display Lighting Laboratory staffed with a specialized team of academic researchers, students and industrial partners focused on identifying and implementing engineering solutions for lighting display-related problems; and (5) conducting research, development and demonstration for HSL essential to the resolution of technological barriers to commercialization
Feedback Ramp Metering Using Godunov Method Based Hybrid Model
This paper presents a feedback control design for an isolated freeway ramp that utilizes a hybrid dynamical model for the traffic using Godunov\u27s numerical technique. Feedback ramp metering designs in the past have relied on either discretized linearized method such as ALINEA, or nonlinear feedback designs based on ordinary differential equations for the traffic model. However, lumped parameter models fail to represent the rarefaction wave phenomenon of the distrbuted model. This paper uses Godunov based hybrid lumped model based on which feedback control design is proposed, and simulation results for the model are presented
A Novel RGBW Pixel for LED Displays
In display technology, pixels are composed of three primary colors: red, green, and blue (RGB). Using the primary colors provides the ability to generate variety of hues including achromatic point (AP) (white light). This concept is applied in Light emitting diode (LED) displays where each pixel consists of RGB LEDs. Although using compact RGB light in LED displays provides a wide color gamut, many issues arise due to dissimilarities in optical and physical characteristics of LEDs such as: uniform spatial light mixing and distribution of AP, and AP maintenance and thermal management. Power consumption is also a major concern in LED displays. In this paper, the issues with current RGB pixel architecture such as non-uniform mixing and distribution of AP, energy efficiency and a solution to these issues by introducing a new pixel configuration consisting of red, green, blue and white (RGBW) are discussed. Experimental results as well as theoretical analysis of the new configuration are presented and discussed
Model-based methodology for validation of traffic flow detectors by minimizing human bias in video data processing
This paper provides a model-based method for analysis and hypothesis testing for paired data where one source of data has to be validated against another source of data that contains subjective and dynamic errors. This study deals with human-observed flow counts collected from traffic videos of freeway cameras. The available videos are mainly used for the purpose of manual observation by transportation personnel in case of emergency. This amounts to a varying inconsistency of the quality of the videos, which presents an additional challenge when analyzing the data. Video processing cannot be performed due to the mentioned issues with regard to the video quality. The processing has to be manually performed by humans who unfortunately have an inherent bias. If the video data have to be used for validating flow detector sensors, then a technique that performs validation with subjective and dynamic erroneous data as a result of the human bias is needed. This paper presents a methodology to deal with this issue. It is based on statistical testing with heteroscedasticity, which is demonstrated through a case study using data from traffic flow detectors and traffic cameras installed on highways in the Southern Nevada Region. A model for the relationship between the video ratings and the distribution of the human errors is developed taking into consideration the human bias. A method for identification of faulty detectors is also demonstrated based on the developed technique
Level-up : expand undergraduate research capacity (and serve faculty) through vertically integrated projects
The Level-up workshop will challenge exclusive and exclusionary models for undergraduate research experiences, and it will give participants tools to expand undergraduate research to serve all students. The model and associated tools are adaptable, and they have been implemented in 44 colleges and universities of varying sizes, settings and missions in 12 countries