Wireless technology provides accurate positioning in indoor environments using time of arrival(TOA) based ranging techniques. However, the positioning accuracy is degraded due to the ranging errors caused by multipath...Wireless technology provides accurate positioning in indoor environments using time of arrival(TOA) based ranging techniques. However, the positioning accuracy is degraded due to the ranging errors caused by multipath and non-line-of-sight(NLOS) propagation. In this paper, a ranging error correction method is proposed to improve positioning performance. A TOA ranging error model(TREM) is built to provide the prior information for ranging error correction first. The mean value of TREM within a certain interval is used as the ranging error correction value(RECV). As the RECV may be unreasonable sometimes, we adjust it according to the actual positioning situation and then exploit the final RECV to correct ranging data. The experimental results show that the proposed method could well reduce ranging errors and the positioning performance is obviously improved when using corrected ranging data.展开更多
The present study aims to better understand the relationship between energy intensity and its determinants including energy price, technological progress, economic structure, and energy mix using the autoregressive di...The present study aims to better understand the relationship between energy intensity and its determinants including energy price, technological progress, economic structure, and energy mix using the autoregressive distributed lag(ARDL) bounds approach and vector error correction model technique. Based on China's time series over 1985-2014, the ARDL bounds approach yields empirical evidence that confirms the existence of long run relationship between energy price, technological progress, economic structure, energy mix, and energy intensity. The results show that technological progress is an important driver for the declining energy intensity in short and long run. Energy price has not been demonstrated as an important role in decreasing energy intensity in the short run. The high share of coal use in total energy use may be responsible for China's high energy intensity.However, the relative change in economic sectors plays a minor role in energy intensity reduction during the past years. In the long run, technological progress, energy mix and energy prices Granger cause energy intensity, but not vice versa except for the energy mix.展开更多
Inner Mongolia is the important ecological barrier zone in northern China,which plays an important role in the prevention and control of wind in the regional ecosystem.Based on the Revised Wind Erosion Equation(RWEQ)m...Inner Mongolia is the important ecological barrier zone in northern China,which plays an important role in the prevention and control of wind in the regional ecosystem.Based on the Revised Wind Erosion Equation(RWEQ)model and the cost-recovery method,this study simulated the wind erosion prevention service(WEPS)in Inner Mongolia in 2010 and 2015,investigated the spatial pattern of material and monetary value of WEPS,and analyzed the differences among various cities and various ecosystems.The results indicated that the total WEPS of Inner Mongolia was estimated to be 73.87×10^(8) t in 2015,which was 4.61×10^(8) t less than in 2010,while the monetary value of WEPS was calculated to be 738.66×10^(8) yuan in 2015,which was 46.16×10^(8) yuan less than in 2010.Among all the leagues and cities,Xilin Gol League supported the highest WEPS,reaching 18.65×10^(8) t in 2015,while Wuhai provided the lowest.The WEPS of Hulunbeier increased the most,by 4.37×10^(8) t from 2010 to 2015.The WEPS in the grassland ecosystem was the highest among the different ecosystems,accounting for more than55%of the total WEPS in Inner Mongolia,but it was reduced by 1.05×10^(8) t during the same period.The WEPS in the forest ecosystem increased the most,reaching 0.19×10^(8) t.This study found that the implementation of projects such as returning farmland to forests and grasses and sand control effectively increased the WEPS by increasing the forest area.However,unsuitable land use increased the desertification of ecosystems which resulted in a reduction of WEPS in Inner Mongolia.展开更多
Bleaching experiments on Chinese pottery fine grains were conducted under sunlight and laboratory light conditions. It is found that the thermoluminescence (TL) at high temperatures can be bleached significantly, but ...Bleaching experiments on Chinese pottery fine grains were conducted under sunlight and laboratory light conditions. It is found that the thermoluminescence (TL) at high temperatures can be bleached significantly, but no effects were observed on TL signals used for the pre-dose dating technique. It is concluded that the pre-dose dating technique can be applied to samples even after light exposures. Pottery samples of Tang Dynasty and New Stone Age were studied. Modifications to routine pre-dose dating technique are proposed with adding preheat procedures and using saturation exponential fitting for the sensitivity change data. The modified technique can extend the dating range to New Stone Age.展开更多
基金supported in part by Huawei Innovation Research Program(Grant No.YB2013020011)
文摘Wireless technology provides accurate positioning in indoor environments using time of arrival(TOA) based ranging techniques. However, the positioning accuracy is degraded due to the ranging errors caused by multipath and non-line-of-sight(NLOS) propagation. In this paper, a ranging error correction method is proposed to improve positioning performance. A TOA ranging error model(TREM) is built to provide the prior information for ranging error correction first. The mean value of TREM within a certain interval is used as the ranging error correction value(RECV). As the RECV may be unreasonable sometimes, we adjust it according to the actual positioning situation and then exploit the final RECV to correct ranging data. The experimental results show that the proposed method could well reduce ranging errors and the positioning performance is obviously improved when using corrected ranging data.
文摘The present study aims to better understand the relationship between energy intensity and its determinants including energy price, technological progress, economic structure, and energy mix using the autoregressive distributed lag(ARDL) bounds approach and vector error correction model technique. Based on China's time series over 1985-2014, the ARDL bounds approach yields empirical evidence that confirms the existence of long run relationship between energy price, technological progress, economic structure, energy mix, and energy intensity. The results show that technological progress is an important driver for the declining energy intensity in short and long run. Energy price has not been demonstrated as an important role in decreasing energy intensity in the short run. The high share of coal use in total energy use may be responsible for China's high energy intensity.However, the relative change in economic sectors plays a minor role in energy intensity reduction during the past years. In the long run, technological progress, energy mix and energy prices Granger cause energy intensity, but not vice versa except for the energy mix.
基金The Strategic Priority Research Program of Chinese Academy of Sciences(XDA20020402)The National Natural Science Foundation of China(41971272)。
文摘Inner Mongolia is the important ecological barrier zone in northern China,which plays an important role in the prevention and control of wind in the regional ecosystem.Based on the Revised Wind Erosion Equation(RWEQ)model and the cost-recovery method,this study simulated the wind erosion prevention service(WEPS)in Inner Mongolia in 2010 and 2015,investigated the spatial pattern of material and monetary value of WEPS,and analyzed the differences among various cities and various ecosystems.The results indicated that the total WEPS of Inner Mongolia was estimated to be 73.87×10^(8) t in 2015,which was 4.61×10^(8) t less than in 2010,while the monetary value of WEPS was calculated to be 738.66×10^(8) yuan in 2015,which was 46.16×10^(8) yuan less than in 2010.Among all the leagues and cities,Xilin Gol League supported the highest WEPS,reaching 18.65×10^(8) t in 2015,while Wuhai provided the lowest.The WEPS of Hulunbeier increased the most,by 4.37×10^(8) t from 2010 to 2015.The WEPS in the grassland ecosystem was the highest among the different ecosystems,accounting for more than55%of the total WEPS in Inner Mongolia,but it was reduced by 1.05×10^(8) t during the same period.The WEPS in the forest ecosystem increased the most,reaching 0.19×10^(8) t.This study found that the implementation of projects such as returning farmland to forests and grasses and sand control effectively increased the WEPS by increasing the forest area.However,unsuitable land use increased the desertification of ecosystems which resulted in a reduction of WEPS in Inner Mongolia.
基金a grant to the first author from the Research Grant Council of the Hong Kong Special Administrative Region, China (Grant No. 7105/97P).
文摘Bleaching experiments on Chinese pottery fine grains were conducted under sunlight and laboratory light conditions. It is found that the thermoluminescence (TL) at high temperatures can be bleached significantly, but no effects were observed on TL signals used for the pre-dose dating technique. It is concluded that the pre-dose dating technique can be applied to samples even after light exposures. Pottery samples of Tang Dynasty and New Stone Age were studied. Modifications to routine pre-dose dating technique are proposed with adding preheat procedures and using saturation exponential fitting for the sensitivity change data. The modified technique can extend the dating range to New Stone Age.
