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The measurement of network congestion and degradation of quality of service during distributed denial of service attacks remained an elusive goal. This paper analyzes the impacts that all congested links cause on attack victim and network architecture, introduces the min-cut set and presents a new method to assess the network security situation under DDoS attacks, which computes the influence value...
A routing computation strategy based on improved clustering algorithm is proposed in this paper. It uses a clustering algorithm based on K-means and Dijkstra (CAKD) in topology partitioning. The routing information of each node can be computed during the clustering process, and CAKD reduces the time cost in routing computation and the storage in storing routing information. Experiments showed that,...
A new teaching mode for network design is proposed, which is based on simulating the process of network engineering. The teaching mode can help students to master the necessary designing skills of both small Enterprise LANs and WANs. By simulating the upgrade of networks of a cultural center, the details of design processes are exhibited, such as collecting customer requirements, translating those...
Linear frequency signal (LFM) signal is first used in radar fields due to its remarkable properties, such as wide bandwidth, high energy and high signal-to noise ration. LFM excitation has recently been introduced in medical ultrasonic scanning, and much exciting results were obtained by research staffs. However, there is little study aiming to inspect solid materials utilizing coded excitation. In...
A kind of circularly polarized microstrip antenna is designed in S band. The Wilkinson power divider integrated with the microstrip 90 deg phase shifter is used each unit and the patch is coupled by two orthogonal H-shaped, which can enhance the isolation of the two ports and improve the circularly polarized performance. The antenna array gain is about 14 dB. The axial-ratio value within 3dB from...
Biological system shows a good robustness in nature environment. The purpose of the research of bio-inspired electromagnetic protection is to acquire the thoughts from biology and design the electronic system which has a good capability of anti-interference and high reliability. The paper presents a novel idea that studying bio-inspired electromagnetic protection based on pulsed neural network. The...
Microwave tubes for communication must have high reliability, high power, and a long life of 10 to 15 years. Cathode as the electric source module in microwave vacuum tubes, its reliability and life directly affect the tube's reliability and life. In this paper, electronic gun in short tubes are accelerated to evaluate the lifetime of one kind of microwave vacuum (such as traveling wave tube). In...
Along with the infrared technical rapid development, infrared radiation (IR) infrared thermal image technology is widely applied in nondestructive testing. In this paper, the theoretical basis of IR thermal imaging technology and the method of emissivity and background correction are introduced. The thermal characteristic of one kind of packaging device was studied using infrared thermal imaging technology...
In this paper, the oxide layer of surface of GaSb could be removed by passivation solution. Moreover, different passivation solution have different passivation effect. After passivation treatment, the PL intensity was enlarged. Then the influence of prove passivation time on the intensity of PL was also discussed. When passivation time was 270s, the sample's intensity of PL was the strongest. Additionally,...
In this paper, by controlling the annealing temperature, different morphologies porous ZnO nanobelts could be obtained. Scanning electron microscopy, X-ray diffraction, and PL measurement were applied to analyze the morphologies, structural and optical properties of porous ZnO nanobelts. With the annealing temperature increased, the nanopartiles as the constituent parts of ZnO nanobelts became large...
The GEM [Growth Enterprises Market] board has been run for two years. It has been playing an very important role in the capital market of our country. This paper we use the class of ARCH model for analysis of the stock return in GEM board. We find that it has strong volatility and the volatility lasts a long time. In the end, we provide some recommendations on GEM future development.
Virtual Learning Environment (VLE) plays an important role as the online platform for education in recent years. Due to the significant increase of the shift of focus in utilizing VLE in comparing to the traditional learning environment, modularity and reusability of the services need to be increased as well. Most of the current existing VLEs are being developed using the system-based approach whereby...
Platelet aggregation assay is important in mediating platelet thrombus formation for both medical treatment and prevention. Therefore quick and accurate automatic analyzers for clinic are of urgent requirement all the time. In this paper, design and implementation of embedded control and management system for novel automatic platelet aggregometer is presented, which comes to rapid and quantitative...
China is a big textile and apparel producing country. She is facing much severer challenge and competition than before after joining the global economic system. The need of more professional talents is increasing in textile and apparel industry. At the same time, more and more new technology appears and digital technology is one of them. It brings new opportunity not only for apparel industry but...
Several evaluations of the frequency shifts have been carried out after NIM5 was moved to the new NIM campus at Changping in 2011. The dominate frequency uncertainty was the microwave power related frequency shifts, which was mainly induced by the microwave leakage for NIM5. The experimental results show that fountains are more sensitive to the leakage field below the Ramsey cavity than above the...
A method based on BP neural network is proposed for a class of nonlinear SISO systems. It fits the nonlinear part of the system by learning the weight coefficients of the network on-line, designs the control rules to linearize the system, and assure the global stability. In this paper, the method is popularized in the MIMO systems. Experimental Results of two examples demonstrate the performance of...
At NIM, one GPS carrier phase processing method exclusively for time and frequency transfer, GPSTFP, was developed. Using the method, we implemented the CCD and long baseline time and frequency transfer experiments for performance verification. We can acquire the good agreement among P3 results, GPSTFP results, and the ones by the professional GPS processing software. From one day data, the difference...
In multi-module inverter systems, phase-shifting transformers are needed to compose non-sinusoidal voltages into staircase waveforms That are close to sinusoid. In order to overcome the drawbacks of normal phase-shifting transformers with respect of installation and performance the paper proposes a novel transformer of round shape resembling induction motor. In contrast with In contrast with normal...
Although orthogonal frequency division multiplexing (OFDM) holds great potentials for the next generation wireless communication demands, the carrier frequency offset (CFO) and the DC Offset (DCO) in many practical systems can cause the loss of subcarrier orthogonality and hence severe performance degradation. So far, in the absence of DCO, one most successful CFO estimation approach makes use of...
this paper main around the polyphase structure of filter bank to design. First introduce the theory and the basic structure of multi-sampling. Utilize these can improve the original structure of the filter bank, obtained the corresponding polyphase filter structure. This structure has greatly improved the speed of the filtering computing. Then use FIR filters to realize filtering part, and introduced...
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