The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
For the multi-frequency sensors such as AMSR-E and AMSR-2, the verification results of QP model with dual-channel algorithm (QDCA) soil moisture product are not good in Genhe area. In order to obtain the long time series of soil moisture datasets and improve the accuracy of QDCA in China, this paper improved the vegetation correction method on current QDCA soil moisture algorithm. This paper incorporated...
We experimentally demonstrate an underwater wireless optical communication (UWOC) with 1.4-Gbaud 16-QAM signal using Gaussian mode, orbital angular momentum (OAM) mode and Bessel mode at the wavelength of 532 nm. Underwater bubbles effect is also studied and the BER performance is measured.
We experimentally demonstrate an interesting phenomenon of optical bistability in an integrated optical vortex emitter when injecting high power into the waveguide due to the nonlinear optical effects. We clearly observe a hysteresis loop of the radiation power from the integrated vortex beam emitter when increasing and decreasing the input power.
Electronic payment protocols play a vital role in electronic commerce to ensure the security of transaction process. Current electronic payment protocols based on complex mathematical problems will be vulnerable facing a quantum computer. In order to enhance the security against quantum computers, quantum cryptography is introduced into electronic payment protocols. Although the quantum cryptography...
We present a compact quasi parity-time (PT) symmetric photonic device by using two sets of interleaved tailored gratings. By tailored design, broadband asymmetric optical mode conversion and transmission could be realized over a wide wavelength range from 1.45 μm to 1.65 μm.
We demonstrate an underwater wireless optical transmission link by employing 4-fold orbital angular momentum (OAM) multicasting. The OAM spectrum degradation and crosstalk between multicasted OAM channels and their neighboring ones after 2-m underwater propagation are studied.
Because the inconsistencies always could be found in the comparison, Cox recommended Monte Carlo Method (MCM) to solve this problem and determine the key comparison reference value (KCRV). In the paper, we introduced the MCM in analyzing APMP.M.M-K1 international measurement comparisons. This method, which is based on statistics estimation method, can directly give the degrees of equivalence(DoE)...
This paper proposed a four-wheel drive differential steering method for trajectory tracking. It designed an integral backstepping controller and constructed a simple virtual feedback variable, simplified the controller design and improved the response speed and precision of the system. It connected with the Lyapunov stability criterion which proved the design of control law with global stability....
Nowadays, many researches study the negotiation-based order allocation problem in the supply chain environment, aiming to improve the efficiency of the allocation and the profits of the supply chain members. The competition and cooperation in supplier's side are mainly addressed because of independent orders. In this paper, we analyze an interdependent order allocation problem in a two-echelon supply...
The leg control on foot trajectory planning and contact forces is the most crucial problem for a hydraulic quadruped robot. In contrast with a non-redundant leg, the redundant one generally has larger foot workspace and more agility for leg motion control in rough terrain, however, this redundant joint obviously adds complexities and difficulties to the control system. This work aims to avoid those...
Researchers have done extensive work on establishing an accurate user profile, which has been verified an effective way to implement the user marketing accurately and effectively. In this paper, we will present a feature extraction method based on the fusion of Word2Vec and TF-IDF, and try to establish a user profile. The vector space model (VSM) contains the word vector calculated by Word2Vec, and...
Public cultural sharing service plays an important role in the public cultural platform. The recommender systems can bring users useful cultural resources and information. For safety and security reasons of the cultural resources, the external applications are not allowed to directly access the original resource data stored in the cultural databases by sending recommendation requests. The cultural...
An aging population has inspired the marketing of advanced real-time ambient assisted living solutions. However, the accurate collection of behavior information, recognition of human activities and implementation of this scheme in a real living environment is a challenging task. In this paper, we propose a feasible extended framework which is compatible with common devices and protocols. Specifically,...
The effect of variable-length towed cable on the motion of the secondary towed vehicle should be taken into consideration during its deployment. In order to predict the motion state of the secondary towed vehicle during deploying stage and obtain the position of it and the configuration of towed cable precisely and timely, an upgraded Lagrangian method is adopted. The movement of towed cable's particles...
Increasing frequency is favorable to boost the efficiency of transporting electricity, but it leads to critical insulation challenge inside transformer. To explore the deterioration characteristics of oil-paper insulation system under high-frequency voltage, a column-plate model is adopted to simulate the surface discharge defect and an experimental platform for partial discharge test is established...
the coupling and correlation degree between aircraft systems is higher, and the diagnosis and prognosis of aircraft are more complex. Building a platform for storing and analyzing the aviation big data becomes an important task for civil aviation. This paper proposes a civil aircraft health management big data architecture. The civil aircraft health management system includes airborne PHM, ground...
This paper analyzes the control surface damage of civil aircraft flight control system. Firstly, the fault feature extraction method is analyzed. Then the control surface damage is studied and it is simulated by Simulink. The fault injection is realized by setting the damage coefficient in the simulation model. It simulates seven kinds of fault modes, analyzes the simulated flight data in time domain,...
User profiling is a typical big data service created and utilized by an increasing number of Internet venders, which maintains a customized model of interests or essential attributes of their existing users by looking for insights into their behaviors. The Internet industry's best practices indicate that user profiles can help venders much more sufficiently understand their customers. As a result,...
Support vector machine (SVM) has good generalization performance and is suitable for solving small sample classification problems, so it is often used in the fault diagnosis for aero engine gas path. In this paper, the traditional genetic algorithm and the idea of simulated annealing are combined to optimize the parameters of SVM, and a fault diagnosis method of aero engine gas path based on parameter...
Performance prediction is critical in embedded system design for reducing the turnaround time of software. Using simulation to measure the performance of the whole source code is often too slow, particularly after the modification of the source code due to changes in problem specification. In this paper we present a comprehensive method that combines analytical modeling and statistical approach to...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.