Wideband IMT-Advanced mobile communication systems tend to operate in the high frequency bands due to a relatively large capacity available. Thus, Measurement and modelling methods of radio propaga- tion eharaeteristi...Wideband IMT-Advanced mobile communication systems tend to operate in the high frequency bands due to a relatively large capacity available. Thus, Measurement and modelling methods of radio propaga- tion eharaeteristics are proposed for the field test of Chinese 4th generation （4G） trial system. The mea- surement system is established for 3.5GHz based on the sophistieated measurement instruments and the virtual instrument teehnology. The characteristic parameters of radio propagation sueh as path loss （PL） exponent and shadow fading standard deviation are extracted from measurement data, which result in the path loss model finally. The comparisons with other existing international models results validate our mea- surement in terms of path loss model. Based on the analysis of the existing extension model assumed for the microwave frequency at 3.5GHz, we find that the Stanford University Interim （SUI） model fits very well with the measurement result in the hotspot scenario, while the COST 231 model is closer to the mea- surement result in the suburban scenario. This result provides a measurement-based channel referenee for the development of the future IMT-Advanced systems in China.展开更多
Measures of ionizing radiation were observed in a tower which is 20 meters above the ground relative height. They show a distinct period of 24 hours oscillation during this Februaryl 1 to April 11, 2015. It is suggest...Measures of ionizing radiation were observed in a tower which is 20 meters above the ground relative height. They show a distinct period of 24 hours oscillation during this Februaryl 1 to April 11, 2015. It is suggested that these oscillations originate from radon gas （222Rn） vented from the ground floor. One Russian specific Geiger tube with associated electronics developed at ITA was used, Monitoring of ionizing radiation from 30 keV to l0 MeV shows that the X and gamma rays up to 3.0 MeV is prevalent in the region comes from the Radon gas 222Rn that decay in 214Bi and 214pb in the energies of the gamma rays 0.269, 0.609 and 1.05 MeV respectively. Then, with this simple, portable instrument was possible to monitoring the dynamics of radon gas in the region every interval minutes.展开更多
In order to measure the location of medical micro-devices in the gastrointestinal tract, electro-magnetic methods were developed considering the magnetic permeability of human bodies. Two varieties of electromagnetic ...In order to measure the location of medical micro-devices in the gastrointestinal tract, electro-magnetic methods were developed considering the magnetic permeability of human bodies. Two varieties of electromagnetic localization methods have been implemented: one uses direct current(DC) to generate the elec-tromagnetic field, and the other uses alternating current (AC). The two varieties of the localization principle were analyzed and relevant experiments were made. The experiments show that the alternating electromagnetic method acquires higher accuracy, higher stability and wider measurement range.展开更多
基金supported by the High Technology Research and Development Programme of China(2007AA01Z278)
文摘Wideband IMT-Advanced mobile communication systems tend to operate in the high frequency bands due to a relatively large capacity available. Thus, Measurement and modelling methods of radio propaga- tion eharaeteristics are proposed for the field test of Chinese 4th generation （4G） trial system. The mea- surement system is established for 3.5GHz based on the sophistieated measurement instruments and the virtual instrument teehnology. The characteristic parameters of radio propagation sueh as path loss （PL） exponent and shadow fading standard deviation are extracted from measurement data, which result in the path loss model finally. The comparisons with other existing international models results validate our mea- surement in terms of path loss model. Based on the analysis of the existing extension model assumed for the microwave frequency at 3.5GHz, we find that the Stanford University Interim （SUI） model fits very well with the measurement result in the hotspot scenario, while the COST 231 model is closer to the mea- surement result in the suburban scenario. This result provides a measurement-based channel referenee for the development of the future IMT-Advanced systems in China.
文摘Measures of ionizing radiation were observed in a tower which is 20 meters above the ground relative height. They show a distinct period of 24 hours oscillation during this Februaryl 1 to April 11, 2015. It is suggested that these oscillations originate from radon gas （222Rn） vented from the ground floor. One Russian specific Geiger tube with associated electronics developed at ITA was used, Monitoring of ionizing radiation from 30 keV to l0 MeV shows that the X and gamma rays up to 3.0 MeV is prevalent in the region comes from the Radon gas 222Rn that decay in 214Bi and 214pb in the energies of the gamma rays 0.269, 0.609 and 1.05 MeV respectively. Then, with this simple, portable instrument was possible to monitoring the dynamics of radon gas in the region every interval minutes.
基金the Specialized Research Fundfor the Doctoral Program of Higher Education(No. 20040248033)the National High Technology Research and Development Program (863) of China(No. 2006AA04Z368)
文摘In order to measure the location of medical micro-devices in the gastrointestinal tract, electro-magnetic methods were developed considering the magnetic permeability of human bodies. Two varieties of electromagnetic localization methods have been implemented: one uses direct current(DC) to generate the elec-tromagnetic field, and the other uses alternating current (AC). The two varieties of the localization principle were analyzed and relevant experiments were made. The experiments show that the alternating electromagnetic method acquires higher accuracy, higher stability and wider measurement range.
