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.
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: 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: 2016-01-26
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.
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.
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.
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 | May 5, 2017
WUXI, China, May 6, 2017 /PRNewswire/ -- The final round of the 2017 ASC Student Supercomputer Challenge (ASC17) ended in Wuxi. Tsinghua University stood out from 20 teams from around the world after a fierce one-week competition, becoming grand champion and winning the prize. As the world's largest supercomputing competition, ASC17 received applications from 230 universities around the world, 20 of which got through to the final round held this week at the National Supercomputing Center in Wuxi after the qualifying rounds. During the final round, the university student teams were required to independently design a supercomputing system under the precondition of a limited 3000W power consumption. They also had to operate and optimize standard international benchmark tests and a variety of cutting-edge scientific and engineering applications including AI-based transport prediction, genetic assembly, and material science. Moreover, they were required to complete high-resolution maritime simulation on the world's fastest supercomputer, "Sunway TaihuLight". The grand champion, team Tsinghua University, completed deep parallel optimization of the high-resolution maritime data simulation mode MASNUM on TaihuLight, expanding the original program up to 10,000 cores and speeding up the program by 392 times. This helped the Tsinghua University team win the e Prize award. MASNUM was nominated in 2016 for the Gordon Bell Prize, the top international prize in the supercomputing applications field. The runner-up, Beihang University, gave an outstanding performance in the popular AI field. After constructing a supercomputing system which received massive training based on past big data of transportation provided by Baidu, their self-developed excellent deep neural network model yielded the most accurate prediction of road conditions during the morning peak. The first-time finalist, Weifang University team, constructed a highly optimized advanced heterogeneous supercomputing system with Inspur's supercomputing server, and ran the international HPL benchmark test, setting a new world record of 31.7 TFLOPS for float-point computing speed. The team turned out to be the biggest surprise of the event and won the award for best computing performance. Moreover, Ural Federal University, National Tsing Hua University, Northwestern Polytechnical University and Shanghai Jiao Tong University won the application innovation award. The popular choice award was shared by Saint-Petersburg State University and Zhengzhou University. "It is great to see the presence of global teams in this event," Jack Dongarra, the Chairman of the ASC Expert Committee, founder of the TOP500 list that ranks the 500 most powerful supercomputer systems in the world, and professor at the Oak Ridge National Laboratory of the United States and the University of Tennessee, said in an interview. "This event inspired students to gain advanced scientific knowledge. TaihuLight is an amazing platform for this event. Just imagine the interconnected computation of everyone's computer in a gymnasium housing 100,000 persons, and TaihuLight's capacity is 100 times of such a gym. This is something none of the teams will ever be able to experience again." According to Wang Endong, initiator of the ASC competition, academician of the Chinese Academy of Engineering, and the chief scientist of Inspur Group, the rapid development of AI at the moment is significantly changing human society. At the core of such development are computing, data and algorithms. With this trend, supercomputers will become an important infrastructure for intelligent society in the future, and their speed of development and standards will be closely related to social development, improvement in livelihood, and progress of civilization. ASC competition is always committed to cultivating future-oriented, inter-disciplinary supercomputing talents to extend the benefits to the greater population. ASC17 is jointly organized by the Asian Supercomputing Community, Inspur Group, the National Supercomputing Center in Wuxi, and Zhengzhou University. Initiated by China, the ASC supercomputing challenge aims to be the platform to promote exchanges among young supercomputing talent from different countries and regions, as well as to groom young talent. It also aims to be the key driving force in promoting technological and industrial innovations by improving the standards in supercomputing applications and research. To view the original version on PR Newswire, visit:http://www.prnewswire.com/news-releases/tsinghua-university-won-asc17-championship-big-time-300452166.html
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: 2017-01-12
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.
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.