Beihang University, previously known as Beijing University of Aeronautics and Astronautics is a major public research university located in Beijing, China.It is a member of China's Project 211 and Project 985 group of key state universities, with a heavy focus on high level technological and scientific research. BUAA was founded on October 25, 1952 with an area of over 100 hectares, BUAA is one of China's leading universities on research and education. It is regarded as one of the best engineering universities in China and has a great influence on China's aeronautical and astronautical industry. Wikipedia.
News Article | May 4, 2017
The first C919 passenger jet made by the Commercial Aircraft Corporation of China (COMAC) is seen during a test in Shanghai, China April 16, 2017. Picture taken April 16, 2017. REUTERS/Stringer ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. EDITORIAL USE ONLY. CHINA OUT. NO COMMERCIAL OR EDITORIAL SALES IN CHINA. SHANGHAI (Reuters) - China's home-grown C919 passenger jet is set to take to the skies on its long-delayed maiden flight on Friday, a major step for Beijing as it looks to boost its profile in the global aviation market. The narrow-body aircraft, which will compete with Boeing's 737 and the Airbus A320, is a key symbol of China's ambitions to muscle into a global jet market estimated to be worth $2 trillion over the next 20 years. The jet will take to the skies at the Shanghai Pudong International Airport on China's affluent east coast, at a ceremony expected to be broadcast live on state TV. The C919, made by state-owned Commercial Aircraft Corporation of China (COMAC) [CMAFC.UL], has seen its test flight pushed back at least twice since 2014 due to production issues, underlining the scale of the task facing Beijing. "The significance is huge, it's the first ever large-frame aircraft made in China," said Xiong Yuexi, a professor and plane design expert at Beihang University in Beijing. "It has a great impact for the Chinese people and the domestic market." China first gave the world a glimpse of the plane, which will be able to carry 158-168 passengers, in November 2015 when it rolled it out at a ceremony in Shanghai. For a FACTBOX on the C919, click Analysts, however, say the production delays mean the C919 will lag technologically behind improved versions of the A320 and 737 which will enter service in the next two years. China Eastern Airlines <600115.SS> is the launch customer for the plane, which COMAC says has 570 orders from 23 customers. The plane also relies on an array of overseas technology, with CFM International, a joint venture between General Electric's aerospace arm and a unit of French firm Safran , supplying the engines. Others include Honeywell International Inc , United Technologies Corp subsidiary Goodrich, Rockwell Collins Inc and a unit of Parker-Hannifin Corp . Conceived in 2008, China wants the C919 to eventually take market share from Boeing and Airbus in the lucrative narrow-body market which accounts for more than 50 percent of the aircraft in service worldwide. For a TIMELINE on the C919, click However, the jet likely faces a lengthy journey from first flight to commercial usage. China's first home-made jet, the regional ARJ-21, received its type certification in December 2014, six years after its first flight and more than 12 years after it was conceived. It made its maiden passenger flight in June last year. Then there is also the daunting task of selling the jet in a global market dominated by Boeing and Airbus. "Aviation is a complex market and you need experience over a long time. Boeing has 100 years, Airbus has over 40 years," said Sinolink Securities analyst Si Jingzhe, adding COMAC still lagged far behind in terms of supply chain know-how. China is pushing for recognition globally of its certification by European and U.S. regulators. Without their certification, China would only be able to sell the jet to a handful of countries that accept its certification standards. Beijing is also already looking beyond the C919, with plans to develop a wide-body long-haul jet with Russia. In November COMAC and its partner United Aircraft Corp said they have started the hunt to find suppliers.
News Article | April 17, 2017
By mimicking the way some fishes eat, a new membrane easily separates and collects spilled oil on water without getting clogged (ACS Nano 2017, DOI: 10.1021/acsnano.6b07918). It could be an efficient and cost-effective way to clean up large oil spills, its developers say. Disaster responders typically clean up large oil spills by containing the slick with floating booms and using skimmers to remove it. Many researchers are developing separation membranes that could potentially be faster and cheaper. These are designed to repel water or attract oil, which helps them separate the two liquids. But the membranes’ pores tend to get clogged with oil, which makes them ineffective after a while. Dongliang Tian of Beihang University, Ziqi Sun of the University of Wollongong, and their colleagues designed a new filter inspired by the throat structures of filter-feeding fish. To filter out tiny prey suspended in water, these fish have bony arches in their throats that get narrower and more closely spaced deeper into the throat. Water flows into the throat, gradually seeping out from the spaces between the arches and out through the gills, while food particles collect at the back. To mimic that process, the researchers made a 3-cm-long stainless steel membrane containing five mesh sections with gradually decreasing pore size—from 150 nm to 30 nm—from one end to the other. They coated the membrane with nanosheets of cobalt oxide which intertwine with each other, forming tiny pockets that lock in water, making the membrane water-attracting, or hydrophilic. Then they tilted the membrane so that the large pores were at the bottom and pushed it with a controller attached to the top, emulating how a ship might push the angled membrane, bottom edge first, through the water. When the driving system moves the membrane through an oil-water mixture, the liquids stream up the membrane. Water permeates the membrane and forms a layer along its hydrophilic surface, preventing oil from clogging the pores. The large pores at the bottom, which encounter the highest water flux, allow water to flow through faster, Tian explains, while the water-logged small pores at the top repel oil, allowing it to easily flow over the top of the membrane into a container. Though oil may pass through the large pores on the first pass, the system makes multiple sweeps through a contaminated area, capturing more oil with each pass. The researchers tested the system in a 100-cm-long, 10-cm-wide sink filled with a mixture of water and one of a variety of oils: crude oil, diesel fuel, corn oil, or hydraulic fluid. They were able to continually collect oil at a calculated rate of 50 liters per minute for each meter length of the membrane, pushing the membrane along the sink more than 2,000 times over 100 minutes. The efficiency drops by less than 3% after those uses, and Tian says cleaning the membrane would restore its efficiency. By comparison, when the team tested a conventional setup by pouring an oil-water mixture through a 90-µm pore size membrane, the membrane became clogged and unusable after 50 uses. This novel filtration technique could enable “one-step, fast, continuous, and high-throughput spilled oil collection,” says Lin Feng of Tsinghua University. The technique has promise for use in large-scale oil spills, especially on lakes and quiet seas, she says. Waves could be a challenge since the water could spill over the top of the membrane into the oil-collection vessel and reduce the membrane’s efficiency.
Beihang University | Date: 2017-01-12
The invention provides a structure self-adaptive 3D model editing method, which includes: given a 3D model library, clustering 3D models of same category according to structures; learning a design knowledge prior between components of 3D models in same group; learning a structure switching rule between 3D models in different groups; after user edits a 3D model component, determining a final group of the model according to inter-group design knowledge prior, and editing other components of the model according to intra-group design knowledge prior, so that the model as a whole satisfies design knowledge priors of a category of 3D models. Through editing few components by the user, other components of the model can be optimized automatically and the edited 3D model satisfying prior designs of the model library can be obtained. The invention can be applied to fields of 3D model editing and constructing, computer aided design etc.
Beihang University and The General Hospital Of The Peoples Libration Army | Date: 2014-09-19
A master-slave same structure teleoperation fracture reduction mechanism includes a frame assembly, two parallel platform assemblies, a top platform connecting plate (9), an operating handle assembly, two fixing assemblies, a controller (15), six movement assemblies and 24 hydraulic pipes (26). The operating handle assembly is located in the middle of the upper platform (5), and the two fixing assemblies are located on the top of the parallel platform assembly. The two parallel platform assemblies are disposed on the frame assembly; the controller (15) and the six movement assemblies are disposed on the frame assembly; A top platform connecting plate (9) is connected to the fixing assembly parallel platform assembly. The hydraulic pipes (26) is in communication with motion hydraulic cylinders (7a) and the other end of the hydraulic pipes is in communication with one of platform hydraulic cylinders (7b). The invention assists a doctor to achieve fracture reduction.
Beihang University | Date: 2016-01-26
The invention provides a light field illuminating method, device and system. The method includes: determining, based on position and angle of rays emitted from a projector and focal length of a lens, position and angle of projection rays obtained after the emitted rays being transmitted through a lens array; determining, based on position and angle of projection rays and light probe array of sampled scene, brightness value of projection rays; converting, based on brightness transfer function of projector, brightness value of projection rays into pixel value of projection input image, generating projection input image based on pixel value of projected input image; and performing light field illumination on target object with projection input image. A projector and a lens array are adopted to achieve light field illumination, so that pixel-level accurate lighting control can be achieved, and various complicated light field environments can be simulated vividly in practical scenario.
News Article | May 11, 2017
China has unveiled its ambitious space programme that will see a mission to land on a asteroid and then try and fire it into the moon's orbit. Ye Peijian, the chief commander and designer of China's lunar exploration programme, revealed that the ultimate aim is to mine the asteroid for metal and minerals or use it as a base for a space station. Trending: Lions may starve to death - just like extinct sabre-tooth tigers did in the Ice Age Speaking at a meeting of space authorities in Beijing, Ye is reported by state media as saying that the first batch of asteroid exploration spacecraft would probably be launched around 2020. Ye noted that many of the asteroids near the Earth contain high concentrations of precious metals, reports Science and Technology Daily, a newspaper run by China's Ministry of Science and Technology. Don't miss: Siberia: Huge dragon and griffin megaliths created by mysterious ancient culture in Altai Mountains He said some of the asteroids may "justify the enormous cost and risk of space exploration" as their economic value could amount to trillions of US dollars, the South China Morning Post reports. The Chinese space programme seems to be far more ambitious than the one announced by Nasa earlier this year, to send two spacecraft to asteroids in 2021 and 2023. Most popular: A low body mass index does not mean you'll develop Alzheimer's disease China plans to 'capture' an asteroid by landing and anchoring a spacecraft on its surface, fire up multiple rocket boosters and project it into the orbit of the moon. The excavation of mineral ores and its transportation back to Earth will be undertaken by robots, Ye was quoted as saying. He estimated that it could take another four decades before China will have the necessary technology and infrastructure in place to mine the asteroid. The scientist did not reveal the asteroid the Chinese government is targeting. Ye was also quoted as saying that there is interest in using an asteroid as the base for a permanent space station. He said the "natural spin of an asteroid could generate a certain amount of centrifugal force that could be transformed into gravity, which is good for the mobility and general health of astronauts." On Wednesday (10 May), China re-activated an airtight research facility in Beijing to start a new experiment with artificial ecological system to pave the way for the design and building of a human settlement on the moon. Four young men and women volunteers entered the Yeugong-1, a self-contained laboratory in Beihang University with a bio-regenerative life support system built four years ago. The volunteers will live in the laboratory, which simulates a lunar environment, for up to 200 days. The volunteers will live in the sealed lab with no input from the outside world., Human waste will be treated with a bio-fermentation process, and experimental crops and vegetables will be grown with the help of food and waste by-products. You may be interested in:
Beihang University | Date: 2016-10-28
The invention provides a line guided 3D model reshaping method, including: 1. extracting a contour of an object from an image, and selecting a contour or main skeleton to create a 2D line database; 2. extracting a 3D editable line, retrieving and suggesting an appropriate 2D contour or skeleton from 2D line database; 3. establishing point-to-point correspondence by matching 2D contour or skeleton to 3D editable line, and reshaping the model using parametric deformation method. By the method, 2D contour or skeleton appropriate for 3D model editable line is automatically suggested from 2D line database of multiple classes of objects to guide 3D model reshaping, and fewer user interactions are required in extracting from input 3D model editable lines such as axes, cross-sections and outlines and producing various types of reshaped models by using parametric deformation method, thereby helping user to design desirable 3D model with speed and ease.
Beihang University | Date: 2017-01-24
An intelligent load-sensing EHA, comprising a variable displacement hydraulic pump, a symmetrical hydraulic cylinder, a feedback module, a pressure-following valve and an execution mechanism. The symmetrical hydraulic cylinder includes a symmetrical plunger, a first cylinder and a second cylinder separated by the plunger. The variable displacement hydraulic pump includes an oil inlet and an oil outlet. An output of the feedback module is to output a greater one of pressures at the first input and the second input to the execution mechanism. The pressure-following valve is connected between the output of the feedback module and an input end of the execution mechanism to reduce an instantaneous flow input to the input end of the execution mechanism and adjust pressure at the input end thereof. The execution mechanism is to receive an output of the feedback module and generate signal for changing displacement of the variable displacement hydraulic pump.
Beihang University | Date: 2016-06-14
The present invention provides a method for video matting via sparse and low-rank representation, which firstly selects frames which represent video characteristics in input video as keyframes, then trains a dictionary according to known pixels in the keyframes, next obtains a reconstruction coefficient satisfying the restriction of low-rank, sparse and non-negative according to the dictionary, and sets the non-local relationship matrix between each pixel in the input video according to the reconstruction coefficient, meanwhile sets the Laplace matrix between multiple frames, obtains a video alpha matte of the input video, according to values of the known pixels of the input video and values of sample points in the dictionary, the non-local relationship matrix and the Laplace matrix; and finally extracts a foreground object in the input video according to the video alpha matte, therefore improving quality of the extracted foreground object.
Sun M.,Beihang University
Reviews of Modern Physics | Year: 2014
Insects can hover, fly forward, climb, and descend with ease while demonstrating amazing stability, and they can also maneuver in impressive ways as no other organisms can. Is their flight inherently stable? If so, how can they maneuver so well? In recent years, significant progress has been made in revealing the dynamic flight stability and flight control mechanisms of insects and has partially answered these questions. Here the most recent advances in this active area are reviewed. The aim is to provide the background necessary to do research in the area and raise questions that need to be addressed in the future. This review begins with an overview of the flapping kinematics and aerodynamics of insect flight. It is followed by a summary of the governing equations of insect motion and the simplified theoretical models used for analysis of dynamic stability and control. Next, the stability properties of hovering flight and forward flight are scrutinized. Then the flight control properties are explored, dealing in turn with flight stabilization control, steady-state control for changing from hovering to forward flight and from one forward-flight speed to another, and control for maneuvers near hovering. Finally, remarks are given on the state of the art of this research field and speculation is made on its outlook in the near future. © 2014 American Physical Society.