Xiao-Yu W.,Aeronautical University
Journal of Computational and Theoretical Nanoscience | Year: 2016
This paper designed the rotary impact type hydraulic jumbolter drive control system, analyzed the working principle of the hydraulic impact system, the promote system, the rotary mechanism hydraulic circuit and the anti-card working hydraulic circuit when jumbolter was working. According to the theory of abstract design variables, deduced the impact energy E, the impact frequency f , the output power N between relationship of the hydraulic impactor work flow Q (or working pressure P) and accelerate the return stroke of the piston Sj . Modeling and simulation were established based on AMESIM. Analyzed the influence of hydraulic impact energy, impact frequency and piston displacement and impact power when changing system working pressure and push power. The simulation results verify the design of rationality and feasibility of the hydraulic pressure drive control system. This result offer foundation to study the hydraulic jumbolter drive system optimum control strategy. © 2016 American Scientific Publishers All rights reserved.
Shen L.,Aeronautical University |
Liu Z.,Aeronautical University
Revista de la Facultad de Ingenieria | Year: 2016
This paper design the corresponding association rules algorithm structure based on Spark. At the same time, we study the implementation of Apriori algorithm on Spark platform. Then combined with their algorithm properties, optimized Apriori algorithm, so that the algorithm can be implemented concurrently at large-scale data environment, in this way to be able to calculate the results in a relatively short period of time. In addition, this optimized algorithm is applied in practice, and the performance of processing time and handling capacity is tested. It had proved that the optimized algorithm is effective.
News Article | November 8, 2016
Over 700 regional students, educators, and parents attended the 10th Annual Aviation Education & Career Expo hosted by ProJet Aviation at their corporate aviation facility at Leesburg Executive Airport. $138,800 in college aviation and flight training scholarships were awarded to students who submitted essays describing their aviation aspirations. “The ability to award this kind of scholarship money is very rewarding. Our aviation community has come together to make dreams a reality for these students,” said Julie O’Brien, ProJet Aviation’s Director of Marketing. “We have changed destinies with this financial and mentoring assistance.” The all-day event featured keynote speakers, industry leaders, performers, and demonstrators. Representatives from more than 56 aviation and aerospace businesses met with students throughout the day to share their experiences, and opportunities for future employment. Speakers and demonstrators included: Shye Gilad, CEO of ProJet Aviation, Kelly Burk, Leesburg, VA Vice-Mayor, Tony Springer, NASA, the US Air Force Honor Guard Drill Team, Kwong Ko, RCA Operator and Drone Demonstrator, The Metropolitan Washington Airport Authority (K-9 Demonstration), Matt Crabbe, Agricultural Aviation Pilot, Heidi Kemner, National Transportation and Safety Board. “Every organization has the opportunity - if not the obligation - to create value beyond profitability,” said Shye Gilad, ProJet Aviation CEO. “It is inspiring to see so many industry leaders contribute to the next generation of aviation and aerospace professionals.” Scholarships and Corporate Sponsorships were donated by host sponsor ProJet Aviation, the Aircraft Owners & Pilots Association (AOPA), Air Culinaire, Av-Ed Flight School, Avemco Insurance, Averett University, Aviation Adventures, Aviation Institute of Maintenance, Aviation Week, Bowling Green State University, Cirrus Aircraft, Community College of Baltimore County, Easy FBO, Embry Riddle Aeronautical University, Frederick Flight Center, Geico Flight Department, General Dynamics, GIF-E North America, Greater Washington Business Aviation Association (GWBAA), The Hoxton Agency, Kansas State University, Liberty University, Marywood University, National Agricultural Aviation Association, National Air Transportation Association, Paragon Aviation Detailing, Paramount Business Jets, Phacil Inc., Pittsburgh Institute of Aeronautics, Eastern Shell Fuels, Sugarloaf 99’s, The Aviation Foundation, Toth Financial Services, USAIG Insurance, Vaughn College of Technology, and Women in Aviation. About The Aviation Education & Career Expo The Aviation Education & Career Expo is one of the largest and most successful aviation education events in the United States, awarding hundreds of thousands of dollars in scholarships to high school students pursuing careers in the aviation and aerospace since its inception in 2005. Over 600 students attend the event each year, which features keynote presentations by industry leaders, static and live aviation demonstrations, and scholarship awards from universities, small businesses, and corporate sponsors. Cofounded by aviation professionals Julie O’Brien and Sarah Thompson, the Expo is committed to helping high school and college students explore the many career opportunities available to them through the world of flight. The Aviation Education & Career Expo is hosted by ProJet Aviation at Leesburg Executive Airport (KJYO), in Leesburg, VA. About ProJet Aviation ProJet Aviation is the DC metro region's premier aviation hospitality company, dedicated to helping people accomplish extraordinary things through the wonder of private flight. The company operates ProJet Center FBO at Leesburg Executive Airport (KJYO), the general aviation gateway to Washington DC, Dulles, and Virginia's Horse & Wine Country. Established in 2007 as a partnership between former airline pilot and entrepreneur Shye Gilad and noted entrepreneur and philanthropist Sheila C. Johnson, Founder & CEO of Salamander Hotels and Resorts, ProJet Aviation combines the operational integrity of the world’s best airlines with the refined service of a world-class resort. ProJet’s numerous accolades include recognition as a Washington Business Journal Best Place to Work, Loudoun County Chamber of Commerce Service Business of the Year, and an Inc. 500/5000 Fastest Growing Company. Find out more at ProJetAviation.com.
Liu W.,Northwestern Polytechnical University |
Yang X.J.,Aeronautical University
Fatigue and Fracture of Engineering Materials and Structures | Year: 2013
The influence of cyclic creep accumulation rate on the damage evolution of MDYB-3 polymethyl methacrylate (PMMA) was experimentally investigated. Fatigue tests were carried out at four stress levels by stress control mode. The steady cyclic creep accumulation stage was observed occupying a substantial proportion of all specimens fatigue processes. Cyclic creep strain growth speed and relaxed modulus degradation rate were deduced as two important indicators for describing the damage evolution characteristics. Linear evolution relations of cyclic creep strain and modulus degradation with cycle times were retrieved from different terms of hysteresis loops. A preliminary model was proposed to be able to estimate the damage extent at different cyclic stress levels. The life predictions by the proposed model were compared with the experiment results and the classical power S-N model, which were demonstrated as a good estimation for the fatigue life. It is feasible to make durability evaluations by the characteristics of steady cyclic creep for multiaxis directed PMMA material. © 2013 Wiley Publishing Ltd.
Ren J.,Aeronautical University |
Li G.,Tsinghua University
Proceedings - 2015 8th International Congress on Image and Signal Processing, CISP 2015 | Year: 2015
In this paper, we develop a new method to identify Wiener systems. Unlike previous techniques for Winer system identification, our method allows the linear dynamic subsystem to be infinite-impulse response (IIR) and the nonlinear function to be non-differentiable, discontinuous and non-invertible. Two input sequences are designed to estimate the nonlinear function as well as the parameters in the linear system. The convergence analysis is also discussed and the performance of the proposed method is illustrated by simulations. © 2015 IEEE.
Xu G.,Aeronautical University |
Deng J.,Shaanxi University of Technology
Physica E: Low-Dimensional Systems and Nanostructures | Year: 2015
The hierarchical branched ZnO nanoarrays (NAs) photoanode was prepared by a two-step hydrothermal method. Vertically aligned long ZnO NWs were first synthesized using as the backbone of hierarchical branched ZnO NAs structure and high quality ZnO NAs branches were grown on the surface of backbone ZnO NAs. The structured films enhance the optical path length through the light scatting effect of branched ZnO NAs and prove the larger internal surface area in NAs film to increase quantum dots (QDs) sensitizer loadings, so the light absorption has an optimization. Compared with the cell based conventional 1D ZnO NAs, the efficiency of the new cells has a great improvement due to the increase of the short circuit current density. © 2015 Published by Elsevier B.V.
Zhouzhou L.,Aeronautical University |
She Y.,Aeronautical University
Journal of Sensors | Year: 2016
Aiming at the perception hole caused by the necessary movement or failure of nodes in the wireless sensor actuator network, this paper proposed a kind of coverage restoring scheme based on hybrid particle swarm optimization algorithm. The scheme first introduced network coverage based on grids, transformed the coverage restoring problem into unconstrained optimization problem taking the network coverage as the optimization target, and then solved the optimization problem in the use of the hybrid particle swarm optimization algorithm with the idea of simulated annealing. Simulation results show that the probabilistic jumping property of simulated annealing algorithm could make up for the defect that particle swarm optimization algorithm is easy to fall into premature convergence, and the hybrid algorithm can effectively solve the coverage restoring problem. © 2016 Liu Zhouzhou and Yanhong She.
Ren J.,Aeronautical University |
Hao J.,Aeronautical University
2012 5th International Congress on Image and Signal Processing, CISP 2012 | Year: 2012
This paper proposes a tracking algorithm that combines Mean Shift with Kalman Filter. Firstly, we use the Kalman filter to predict the target location. Secondly, the Mean Shift tracking algorithm is used to compute the target location with a linear weighted manner. The computed location is treated as a seed point. Finally, the Mean Shift searches target around seed point. Experimental results show that the algorithm can solve the target with suddenly velocity changes, and can more accurately predict the speed of the dynamic target to achieve an accurate tracking. © 2012 IEEE.
Guo W.,Aeronautical University
Chinese Control Conference, CCC | Year: 2014
Capacitive Micro-Accelerometer digital feedback system was developed using the theory of second-order Σ-Δ modulator. The second-order mechanical gauge outfit behaves as two integrators in second-order Σ-Δ modulator and the number of bits of the quantizer is 1 bit. Continuous-time model of the gauge outfit was transformed to discrete-time model based on the IIR theory and the quantizer linear model was established using the LMS arithmetic. Therefore the quasi-linear discrete model was derived. The simulation results shown that the micro-accelerometer system was a low pass system and it had linear phase characteristic approximately in the low frequency band. The simulation results also displayed that the second order noise shaping was performed in the system which made the noise transfer to higher frequency band. Finally the accelerometer system was simulated with the sine signal input, and the results validated that the output and the input are consistent. © 2014 TCCT, CAA.
News Article | January 14, 2016
In the last year, astronomers from the University of Wyoming have discovered roughly 100 of the fastest-moving stars in the Milky Way galaxy with the aid of images from NASA's Spitzer Space Telescope and Wide-field Infrared Survey Explorer (WISE), and use of the Wyoming Infrared Observatory (WIRO) on Jelm Mountain near Laramie. When some swift, massive stars — moving at speeds faster than 50,000 miles an hour — plow through space, they can cause material to stack up in front of them in the same way that water piles up ahead of a ship or a supersonic plane creates a shockwave in front of it. Called bow shocks, these dramatic arc-shaped features in space are helping researchers to uncover massive, so-called runaway stars. "Some stars get the boot when their companion star explodes in a supernova, and others can get kicked out of crowded star clusters," says William Chick, a UW doctoral student in physics, who presented his team's new results on January 5, 2016, at the 227th American Astronomical Society meeting in Kissimmee, FL. "The gravitational boost increases a star's speed relative to other stars." “These are a previously uncatalogued collection of fascinating stars,” says Chip Kobulnicky, a UW professor in the Department of Physics and Astronomy, who supervises Chick. “These are hot, massive stars that are moving through interstellar space at supersonic speed.” Kobulnicky says they use the bow shocks to locate these massive and/or runaway stars. "The bow shocks are new laboratories for studying massive stars and answering questions about the fate and evolution of these stars," he says. The Earth’s sun moves around the Milky Way at a moderate pace, but it is not clear whether it creates a bow shock. By comparison, a massive star with a stunning bow shock, called Zeta Ophiuchi (or Zeta Oph), is traveling around the galaxy faster than the sun, at 54,000 mph (24 kilometers per second) relative to its surroundings. “It’s amazing that you can get something that big moving faster than 50,000 miles an hour,” Chick says. “It’s quite an event.” Both the speed of stars moving through space and their mass contribute to the size and shapes of bow shocks. The more massive a star, the more material it sheds in high-speed winds. Zeta Oph, which is about 20 times as massive as the Earth’s sun, has supersonic winds that slam into the material in front of it. When a massive star with fierce winds like Zeta Oph zips through space, it forms a pile-up of material that glows. This arc-shaped material heats up and shines with infrared light that is assigned the color red in the many pictures of bow shocks captured by Spitzer and WISE. The death of supernovas is responsible for most of the heat created in the galaxy, half of all elements heavier than helium and half of all iron that resides in the human race, Chick says. These stars are five to six times hotter than the sun, which is 5,500 degrees Celsius, Kobulnicky says. Chick and his team used archival infrared data from Spitzer and WISE to identify new bow shocks, including more distant ones that are more difficult to locate. Their initial search turned up more than 200 images of fuzzy red arcs. They then used WIRO to follow up on 80 of these candidates and identify the sources behind the suspected bow shocks. Most turned out to be massive stars. While some of the stars may indeed be fast-moving runaways that were given a gravitational kick by other stars, in a small fraction of the cases, the arc-shaped features may turn out to be something else: dust from stars, or birth clouds of newborn stars. The team plans more observations to confirm the presence of the bow shocks. Stephan Munari, a UW student from Cody, was one of five college students in UW’s Research Experience for Undergraduate Program who participated in this work. Other students were from California State Polytechnic University, Pomona; Case Western Reserve University in Toledo, OH; Embry Riddle Aeronautical University in Daytona Beach, FL; and Front Range Community College in Denver, CO. “I learned more about astronomy, how to conduct research and get some hands-on experience up at WIRO,” says Munari, a senior majoring in mechanical engineering. “What I thought was most interesting was the speed at which these stars were moving. It was a very good experience for me.” Munari says the student work started on campus and consisted of looking through various databases for stars that show different wavelengths of light in infrared. From there, the students found basic bow shock shapes and wrote down their coordinates. The group then traveled to WIRO, pointed the telescope at these stars and obtained more data. Students processed the data and compared the newly discovered stars with those that were already known. “Once we compared them, we could say, for 90 percent of them, we found another bow shock star,” Munari says. “For the other 10 percent, we couldn’t confirm that for sure.” Chick says it was encouraging to receive positive comments about his presentation from Whitney Clavin, a science writer in the media office of NASA’s Jet Propulsion Laboratory (JPL). “Of the eight presentations made that day, she told me I made the best one,” Chick says. Kobulnicky added Chick was one of only 20 astronomers (out of 2,000) invited to make presentations at the conference. Some of the first bow shocks from runaway stars were identified in the 1980s by David Van Buren of NASA's JPL in Pasadena, CA. He and his colleagues found them using infrared data from the Infrared Astronomical Satellite, a predecessor to WISE that scanned the whole infrared sky in 1983. Kobulnicky and Chick belong to a larger team of researchers and students — including Matt Povich from California State Polytechnic University, Pomona — studying bow shocks and massive stars. The National Science Foundation funds their research. Kobulnicky says his group is working on two papers for publication in The Astrophysical Journal, considered the world’s foremost research journal devoted to recent developments, discoveries and theories in astronomy and astrophysics. Information from a NASA news release was used for this article.