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We demonstrated an optical fiber sensor with high sensitivity of temperature and refractive index, we can use it to measure temperature and refractive index simultaneously. The sensing head consists of a section of multimode fiber (MMF) and a section of multi-core fiber (MCF), which is connected between two segments of single-mode fibers to form a Mach-Zehnder interferometer (MZI). A short section...
Two different long-period fiber gratings (LPFGs) are inscribed by high frequency CO2 pulse laser. Coatings effects on inscribed LPFGs bend sensing characteristics are researched. The experimental results show that coatings effects on bending strain characteristics of LPFGs are more obvious, and LPFGs with coatings have more higher strain sensitivity, it is more suitable for used in bending sensor...
Two ESP power supply technologies introduced in this paper use “amplitude modulation & phase shift” as key technique, overcome most of the weakens on the basis of all the advantages of SCR phase shift and voltage regulation technique, improve the performance and collection efficiency of ESP in the bad condition, as well as has energy saving effect. “SCR amplitude modulation & phase shift...
The modulation transfer function of optical sparse aperture system is attenuated among the low and middle frequency band, which causes the degradation and blur. Aimed at this problem, the Annulus array with six apertures is studied. Firstly, a half of its sub-apertures are moved towards center to respectively acquire the multi-frame images that contain integrated information. Secondly, the move scales...
There is a widely application in radar and mobile communication of target localization field recent years about DBF, But the contradiction between precision of target localization and localization out of focus haven't been solved preferably. This article put forward a new linear microphone arrays which own two frameworks that can change space between arrays so that can resolve this contradiction....
In recent years, to escape the spam detection of the text-based spam filtering system, spammers insert junk information into the email with images, and attach it to the message body. The traditional text-based filter cannot handle such spam image. In order to deal with the spam which contains text and images, a filtering method which fuses text, image and other multi-modal features is proposed in...
Enterprise multi-project environment is more and more popular. How to conduct knowledge management efficiently in multi-project environment becomes a difficult problem. Aimed at the situation of multi-project knowledge management, this paper constructs an enterprise multi-project KM model based on Knowledge Grid, with multi-project coordination mechanism and Knowledge Unit theory. After that, a multi-project...
While the outsourced storage services bring economy and convenient, it also brings a lot of security problems, especially data security. In recent years a lot of research have done on the protection of data security in outsourcing storage services, most of them focus on the data privacy and integrity protection, and pay little attention to the guarantee of data freshness. The data freshness guarantee...
Based on the principle of superposition, the Infinite - length Linear Heat-source Model is applied to the analysis of the long-term performance of Ground Heat Exchanger for Ground Source Heat Pump. It is shown that the inlet and outlet temperatures of the Ground Heat Exchanger vary with the start time of the operation even if under the same annual dynamic load. The result suggests that the load distribution...
In view of inherent insufficiency of traditional fault diagnosis expert system in the aspect of knowledge representation, together with the characteristics of fault tree, hierarchical model and expert system, this paper puts forward a knowledge base maintenance approach based on Object-Frame knowledge representation, in which domain specific knowledge is expressed by combinations of the relevant objects'...
The development of cloud storage services makes companies who outsourced their data to cloud storage server can't control their data by themselves as before. Then comes the security issues, especially the privacy preserving has become an more important security problem. The users always search their documents through keyword in plaintext, which may leak privacy of users in cloud storage environment...
Currently, as limitations of commercial banks in asset-liability management, there exists the prevalent status quo of mismatch on maturities of assets and liabilities, which may lead to a series of liquidity risk. Diamond and Dybvig (1983) show that while demand-deposit contracts let banks provide liquidity, they expose them to panic-based bank runs. But their model does not provide ways to regulate...
The theory of structural control has been widely accepted in bridges and other structures. The damper in the structure can effectively control the vibration response caused by earthquakes, strong winds, the trains and other reasons. With the high-speed railway construction, the transverse vibration problem become more prominent in railway bridges. The appropriate setting dampers in steel plate girder...
Design of cooling system for hot stamping die was studied in this paper, through analysis of phase transformation of stamping parts, die structure strength and deformation requirements of die and stamping parts. Order of cooling system parameters effecting on stamping parts temperature was studied, it was found that, effect of distance between die surface and cooling pipe was the greatest influencing...
Computer simulation can help to analyze temperature field during deformation, thickness variation of sheet metal and distribution of stress and strain, etc. in the hot forming process, according to numerical simulation of hot stamping, conclusions would be found: sheet metal must be formed within one second with pressing speed between 50mm/s and 150mm/s, and temperature before stamping should be lower...
In order to study crack and springback phenomena of hot stamping parts, experiment researches were done through home-made hot stamping die. The following results were found: friction of plate and die was the main reason of crack during hot stamping, and reducing of friction was effective method to deal with crack; blank holder force (BHF) wasn't needed, and blank holder wasn't needed for hot stamping...
Based on existing problems of security in wireless sensor networks, this paper analyzes the resistance against capture, network connectivity extending and memory overhead among random key pre-distribution schemes, q-composite pre-distribution schemes and symmetric key algorithm. A novel random key algorithm is proposed combining random and authentication. Finally, the algorithm is compared with any...
The objective of this paper is to provide an analysis of the amplitude statistics of Ku-Band SAR ground clutter data using Weibull, Gamma, K and lognormal distribution. Their goodness-of-fit have been carried out by Kolmogorov-Smirnov (K-S) test after the estimation of the distribution parameters. The results show that Gamma distribution approximates much better the value of the empirical probability...
Application specific integrated emission chips are incompatible with one another in terms of the telecontrol-code formats, an obstacle for the universal application of remote controllers. In this paper MCS-51 microprocessor is used to simulate the emission of remote codes belonging to PT2248 chips, programs are designed to produce specific telecontrol-codes, assisted by peripheral circuits to transmit...
In this paper, a bistatic clutter geometrical model is proposed. The model can accurately describe the geometrical relationship between the bistatic radars and the clutter scatterers, and it can be applied in any bistatic geometrical scenarios. On the basis of analyzing the geometrical relationship between the bistatic radars and the clutter scatterers in varying geometrical scenarios, the paper formulates...
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