The optimization of network performance in a movement-assisted data gathering scheme was studied by analyzing the energy consumption of wireless sensor network with node uniform distribution. A theoretically analytica...The optimization of network performance in a movement-assisted data gathering scheme was studied by analyzing the energy consumption of wireless sensor network with node uniform distribution. A theoretically analytical method for avoiding energy hole was proposed. It is proved that if the densities of sensor nodes working at the same time are alternate between dormancy and work with non-uniform node distribution. The efficiency of network can increase by several times and the residual energy of network is nearly zero when the network lifetime ends.展开更多
Objective The present study aimed to test whether exposure to radiofrequency electromagnetic fields （RF-EMF） emitted by mobile phone base stations may have effects on salivary alpha-amylase, immunoglobulin A （IgA）...Objective The present study aimed to test whether exposure to radiofrequency electromagnetic fields （RF-EMF） emitted by mobile phone base stations may have effects on salivary alpha-amylase, immunoglobulin A （IgA）, and cortisol levels. Methods Fifty seven participants were randomly allocated to one of three different experimental scenarios （22 participants to scenario 1, 26 to scenario 2, and 9 to scenario 3）. Each participant went through five 50-minute exposure sessions. The main RF-EMF source was a GSM-900-MHz antenna located at the outer wall of the building. In scenarios 1 and 2, the first, third, and fifth sessions were ＂low＂ （median power flux density 5.2 μW/m^2） exposure. The second session was ＂high＂ （2126.8 μW/m^2）, and the fourth session was ＂medium＂ （153.6 μW/m^2） in scenario 1, and vice versa in scenario 2. Scenario 3 had four ＂low＂ exposure conditions, followed by a ＂high＂ exposure condition. Biomedical parameters were collected by saliva samples three times a session. Exposure levels were created by shielding curtains. Results In scenario 3 from session 4 to session 5 （from ＂low＂ to ＂high＂ exposure）, an increase of cortisol was detected, while in scenarios 1 and 2, a higher concentration of alpha-amylase related to the baseline was identified as compared to that in scenario 3. IgA concentration was not significantly related to the exposure. Conclusions RF-EMF in considerably lower field densities than ICNIRP-gnidelines may influence certain psychobiological stress markers.展开更多
During the process of thunderstorm in a county on June 23,2015,eight mobile base stations in the region were damaged.The reasons for the damage caused by the thunderstorm were discussed through on-the-spot investigati...During the process of thunderstorm in a county on June 23,2015,eight mobile base stations in the region were damaged.The reasons for the damage caused by the thunderstorm were discussed through on-the-spot investigation,and some countermeasures were proposed.展开更多
China has mobile phone penetration rate of over 96.2%.Mobile phone has become the largest Internet terminal for Chinese Internet users.Population geographic distribution in earthquake zones can be got based on mobile ...China has mobile phone penetration rate of over 96.2%.Mobile phone has become the largest Internet terminal for Chinese Internet users.Population geographic distribution in earthquake zones can be got based on mobile phone positioning and map matching.For reducing earthquake black-box stage,we propose a real-time collection,correction and schedule algorithm of population position data by four stream processing environments(Redis,Hbase,Kafka,and Spark Streaming)in this paper.For labeling precisely population geographic distribution on the network map,matching of population geographic coordinates and map coordinates are optimized by sample comparison based on location data of mobile communication base stations and prefecture level cities.The test result shows the proposed system is high efficient and can rapidly respond to any emerging parallel tasks during the earthquake.A high-precision heat map of affected population can be produced and published on-line within 2 min after the devastating earthquake happened.展开更多
A case of villagers suffering lightning stroke around the tower of a mobile communication base station was investigated to analyze its reasons,and the countermeasures against lightning stroke were proposed. The result...A case of villagers suffering lightning stroke around the tower of a mobile communication base station was investigated to analyze its reasons,and the countermeasures against lightning stroke were proposed. The results show that the lightning stroke event is related to dispersed lightning stroke. To avoid the damage caused by lightning stroke,it is needed to equip a house in the dispersed lightning stroke zone with lightning protection system and spread lightning protection knowledge among the villagers.展开更多
For several lightning-strike disasters related to base station iron tower of mobile communication carrier operator, disaster-inducing factors were analyzed. The reason was as below： after lightning receptor of base s...For several lightning-strike disasters related to base station iron tower of mobile communication carrier operator, disaster-inducing factors were analyzed. The reason was as below： after lightning receptor of base station iron tower of mobile communication carder operator was struck by lightning, electromagnetic radiation was generated in the process lightning current leaking into the ground. In addition, it was lightning scattered- strike phenomenon induced by overhead lightning rod, that is, ground lightning falling density around overhead lightning rod was larger than mean at the site. Finally, some improvement measures were put forward.展开更多
基金Project(60873081)supported by the National Natural Science Foundation of ChinaProject(NCET-10-0787)supported by Program for New Century Excellent Talents in UniversityProject(11JJ1012)supported by the Natural Science Foundation of Hunan Province,China
文摘The optimization of network performance in a movement-assisted data gathering scheme was studied by analyzing the energy consumption of wireless sensor network with node uniform distribution. A theoretically analytical method for avoiding energy hole was proposed. It is proved that if the densities of sensor nodes working at the same time are alternate between dormancy and work with non-uniform node distribution. The efficiency of network can increase by several times and the residual energy of network is nearly zero when the network lifetime ends.
基金funded by the Land Salzburg Federal Government,Science Department,and Mr.Daniell Porsche,Chairman of the Paracelsus-School at St.Jakob am Thurn,Salzburg,Austria.
文摘Objective The present study aimed to test whether exposure to radiofrequency electromagnetic fields （RF-EMF） emitted by mobile phone base stations may have effects on salivary alpha-amylase, immunoglobulin A （IgA）, and cortisol levels. Methods Fifty seven participants were randomly allocated to one of three different experimental scenarios （22 participants to scenario 1, 26 to scenario 2, and 9 to scenario 3）. Each participant went through five 50-minute exposure sessions. The main RF-EMF source was a GSM-900-MHz antenna located at the outer wall of the building. In scenarios 1 and 2, the first, third, and fifth sessions were ＂low＂ （median power flux density 5.2 μW/m^2） exposure. The second session was ＂high＂ （2126.8 μW/m^2）, and the fourth session was ＂medium＂ （153.6 μW/m^2） in scenario 1, and vice versa in scenario 2. Scenario 3 had four ＂low＂ exposure conditions, followed by a ＂high＂ exposure condition. Biomedical parameters were collected by saliva samples three times a session. Exposure levels were created by shielding curtains. Results In scenario 3 from session 4 to session 5 （from ＂low＂ to ＂high＂ exposure）, an increase of cortisol was detected, while in scenarios 1 and 2, a higher concentration of alpha-amylase related to the baseline was identified as compared to that in scenario 3. IgA concentration was not significantly related to the exposure. Conclusions RF-EMF in considerably lower field densities than ICNIRP-gnidelines may influence certain psychobiological stress markers.
文摘During the process of thunderstorm in a county on June 23,2015,eight mobile base stations in the region were damaged.The reasons for the damage caused by the thunderstorm were discussed through on-the-spot investigation,and some countermeasures were proposed.
基金supported by the Special Fund of Information Operational Projects from China Earthquake Administration(K1809-4)
文摘China has mobile phone penetration rate of over 96.2%.Mobile phone has become the largest Internet terminal for Chinese Internet users.Population geographic distribution in earthquake zones can be got based on mobile phone positioning and map matching.For reducing earthquake black-box stage,we propose a real-time collection,correction and schedule algorithm of population position data by four stream processing environments(Redis,Hbase,Kafka,and Spark Streaming)in this paper.For labeling precisely population geographic distribution on the network map,matching of population geographic coordinates and map coordinates are optimized by sample comparison based on location data of mobile communication base stations and prefecture level cities.The test result shows the proposed system is high efficient and can rapidly respond to any emerging parallel tasks during the earthquake.A high-precision heat map of affected population can be produced and published on-line within 2 min after the devastating earthquake happened.
文摘A case of villagers suffering lightning stroke around the tower of a mobile communication base station was investigated to analyze its reasons,and the countermeasures against lightning stroke were proposed. The results show that the lightning stroke event is related to dispersed lightning stroke. To avoid the damage caused by lightning stroke,it is needed to equip a house in the dispersed lightning stroke zone with lightning protection system and spread lightning protection knowledge among the villagers.
文摘For several lightning-strike disasters related to base station iron tower of mobile communication carrier operator, disaster-inducing factors were analyzed. The reason was as below： after lightning receptor of base station iron tower of mobile communication carder operator was struck by lightning, electromagnetic radiation was generated in the process lightning current leaking into the ground. In addition, it was lightning scattered- strike phenomenon induced by overhead lightning rod, that is, ground lightning falling density around overhead lightning rod was larger than mean at the site. Finally, some improvement measures were put forward.
