Time filter

Source Type

Liu Y.,Beijing Polytechnic College
Lecture Notes in Electrical Engineering | Year: 2013

In this paper, by analyzing the shortcomings of existing technologies, we introduced a convenient and flexible smart home system based on Internet of Things. We have developed a demo version of this system and used a cell phone to query and control it locally and remotely. The experimental results show that this system can provide a real-time and reliable management for the smart home. It is believed that with the development of Internet of Things, smart home system will become more intelligent and multiplicity. © 2013 Springer-Verlag London.

Gai K.-R.,Beijing Polytechnic College
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2012

In order to develop space or ground large optics system, the technology study of large aperture SiC mirror were studied in detail. In this article the optimization of new mirror materials was introduced, the fabrication technologies of SiC mirror were studied, and the application of SiC mirrors was elaborated. At the same time, the SiC mirror technology and directions in china were expressed. © 2012 SPIE.

Sun X.J.,Beijing Polytechnic College
Applied Mechanics and Materials | Year: 2014

The development of science and technology has driven the progress of the examination system, through the development of database and intelligent, data mining, the database technology is also developed. But at present there are insufficient data mining scope, so must strengthen the examination analysis system has the function of data preprocessing, data mining to meet the needs of data mining algorithm, and accelerate the execution efficiency of data mining, to prevent the deviation, as a result more than the entire process of data mining and data pretreatment cost and time needed to about forty percent less. So, in order to analyze the test system in a large number of test data, in this way is very necessary to carry on the pretreatment before the data into the database is the important factor of data mining. © (2014) Trans Tech Publications, Switzerland.

Chen J.,Beijing Polytechnic College
Jinshu Rechuli/Heat Treatment of Metals | Year: 2012

Hot-dip galvanizing experiments were carried out on pure iron, Q195, Q235 and Q345 steels in baths of pure zinc, 0.1%Ni, 0.1%Co, 0.1%Ni+0.1%Co, 0.1%Ni+0.2%, respectively. Microstructure and thickness of the coatings were observed and measured under microscope and scanning electron microscopye and the effect of the alloying elements on microstructure and thickness of the coatings was investigated. The results show that Ni and Co have a certain effect on these four substrate materials. Addition Co alone can fine the microstructure of the coatingg, but it, has little effect on thickness. Addition 0.1% Ni alone can control silicon reaction, especially for Q235 steel substrate. Addition both Ni and Co can greatly restrain silicon reaction (namely Sandelin effect) and a thin and compact coating can be obtained.

Zhu Y.Z.,Beijing Polytechnic College
International Journal of Security and its Applications | Year: 2016

With the development of computer network technology, more closely the relationship between people and network.The current network security problem has also been gradually into the public's field of vision, actively carried out on the network intrusion detection becomes an important direction of the development of the network security technology.On the basis of the original BP neural network, this paper puts forward an improved algorithm, and applied to network intrusion detection. After the test, the method is better than traditional convergence, better performance. © 2016 SERSC.

Liu Y.H.,Beijing Polytechnic College
Applied Mechanics and Materials | Year: 2014

In recent years, China's coal industry accidents occur frequently, seriously affect the development of the coal industry, for the job site in the coal mine monitoring system installed several monitoring of coal mine production equipment to ensure safety and reliable operation of equipment. However, a plurality of building monitoring system meets some problems, such as reducing the waste of resources and production costs, and improve the level of safety management, the use of embedded technology designed S3c2440 based multi-protocol converter, prompting the original coal use different protocols and applications compatible with a variety of monitoring systems, monitoring of information data seamless transfer and access into the Ethernet switch, the status of the mine production equipment is transferred to the centralized control center for centralized management. This paper will be based on coal mine multi-protocol converter design S3c2440 detailed analysis and research. © (2014) Trans Tech Publications, Switzerland.

Chen H.,Beijing University of Civil Engineering and Architecture | Wei P.,Beijing Polytechnic College
Energy Procedia | Year: 2011

A theoretical analysis of novel direct expansion heat pump system incorporating a Photovoltaic/Thermal (PV/T) solar collector acting as the evaporator is presented in this paper. Based on energy balance of each parts of the vacuum-tube-PV sandwich and the four main components of the heat pump system, mathematical models are developed to evaluate the energy performance of the heat pump and the electrical and thermal performances of the PV cells, under the climatic conditions of the City of Nottingham, UK. The simulation results indicate that the average monthly thermal and electrical efficiencies are 0.752 and 0.155 respectively, and the average monthly COP reaches 5.35 © 2011 Published by Elsevier Ltd.

Zhou K.Y.,Beijing Polytechnic College
Applied Mechanics and Materials | Year: 2013

The dynamics is important for the robot system simulation and feedback control design, so the dynamics of load-unload bagged materials robot is analyzed based on the second kind Lagrange theory, and the precise dynamics model is established. The solution of dynamics differential equations are solved by procedure matlab, dynamics Simulation is analyzed based on platform of ADMAS dummy prototype, obtain series of graph angular acceleration, driving force, moment. © (2013) Trans Tech Publications, Switzerland.

Jiao S.,Beijing Polytechnic College
IOP Conference Series: Earth and Environmental Science | Year: 2014

The leaf area index (LAI) is significant for research on global climate change and ecological environment. China HJ-1 satellite has a revisit cycle of four days, providing CCD data (HJ-1 CCD) with a resolution of 30 m. However, the HJ-1 CCD is incapable of obtaining observations at multiple angles. This is problematic because single angle observations provide insufficient data for determining the LAI. This article proposes a new method for determining LAI using HJ-1 CCD data. The proposed method uses background knowledge of dynamic land surface processes that are extracted from MODerate resolution Imaging Spectroradiometer (MODIS) LAI 1-km resolution data. To process the uncertainties that arise from using two data sources with different spatial resolutions, the proposed method is implemented in a dynamitic Bayesian network scheme by integrating a LAI dynamic process model and a canopy reflectance model with remotely sensed data. Validation results showed that the determination coefficient between estimated and measured LAI was 0.791, and the RMSE was 0.61. This method can enhance the accuracy of the retrieval results while retaining the time series variation characteristics of the vegetation LAI. The results suggest that this algorithm can be widely applied to determining high-resolution leaf area indices using data from China HJ-1 satellite even if information from single angle observations are insufficient for quantitative application.

Jiao S.,Beijing Polytechnic College
IOP Conference Series: Earth and Environmental Science | Year: 2014

Crop structural parameter, i.e. leaf area index(LAI), is the main factor that can effect the solar energy re-assignment in the canopy. An automatic measuring system which is designed on the basis of wireless sensors network(WSN) is present in this paper. The system is comprised of two types of node. One is the measurement nodes which measured solar irradiance and were deployed beneath and above the canopy respectively, and another is a sink node which was used to collect data from the other measurement nodes. The measurement nodes also have ability to repeater data from one node to another and finally transfer signal to the sink node. Then the collected data of sink node are transferred to the data center through GPRS network. Using the field data collected by WSN, canopy structural parameters can be calculated using the direct transmittance which is the ratio of sun radiation captured by the measurement node beneath and above the canopy on different sun altitude angles. The proposed WSN measurement systems which is consisted of about 45 measurement node was deployed in the Heihe watershed to continually observe the crop canopy structural parameters from 25 June to 24 August 2012. To validate the performance of the WSN measured crop structural parameters, the LAI values were also measured by LAI2000. The field preliminary validation results show that the designed system can capture the varies of solar direct canopy transmittance on different time in a day, which is the basis to calculate the target canopy structural parameters. The validation results reveal that the measured LAI values derived from our propose measurement system have acceptable correlation coefficient(R2 from 0.27 to 0.96 and averaged value 0.42) with those derived from LAI2000. So it is a promising way in the agriculture application to utilize the proposed system and thus will be an efficient way to measure the crop structural parameters in the large spatial region and on the long time series.

Loading Beijing Polytechnic College collaborators
Loading Beijing Polytechnic College collaborators