This paper presents the global solar radiation (GSR) and cloud transmittance factor (cf) measured at the horizontal surface over a period of one year from 2009 to 2010 using CMP6 Pyranometer and NILUUV Irradiance Mete...This paper presents the global solar radiation (GSR) and cloud transmittance factor (cf) measured at the horizontal surface over a period of one year from 2009 to 2010 using CMP6 Pyranometer and NILUUV Irradiance Meter at Lukla (Latitude 26.69oN,Longitude 86.73?E and Altitude 2850 m) in the foothills of the Mt Everest (8850 m high). Monthly and seasonal variations of global solar radiation as well as correlation between clearness index and cloud transmittance factor at Lukla are presented. The annual average daily global solar radiation is about 3.83 kWh/sq·m/day which is sufficient to promote solar active and passive energy technology at high mountain terrain where there is no other viable alternative sources of energy. The maximum and minimum global solar radiation of 5.33 and 2.08 kWh/sq·m/day is recorded in April and September 2010 respectively. The seasonal variation of solar energy is about 2.87 kWh/sq·m/day and 4.83 kWh/sq·m/day in summer and spring respectively which is not in line with the general trend. The coefficient of determination (R2) between cloud transmittance factor (cf) and clearness factor (K) is found to be 0.97. This novel result can be utilized to estimate the global solar radiation at the horizontal surface where K and cf are available.展开更多
Every year, the French Mediterranean area is subject to wildland fires. The prevention policy promotes the major role of forest layout, for which it is necessary to build appropriate facilities such as reducing igniti...Every year, the French Mediterranean area is subject to wildland fires. The prevention policy promotes the major role of forest layout, for which it is necessary to build appropriate facilities such as reducing ignition and fire propagation risks near the borders of roads and tracks, creating forest tracks to allow firefighters to move safely through the forest during a fire, creating fuel breaks in order to divide up forests and limit the propagation of fire. Land-clearing along a forest track consists in creating discontinuity between the herbaceous stratum and the tree stratum by eliminating the shrubby stratum and cutting tree crowns. It avoids fire propagation by convection, and enables firefighters to deal with the fire in safety. The main difficulty for forest officers is to identify an optimized method to select appropriate tracks to clear, because it is impossible to clear all the tracks each year. Remote sensing tools would seem to be particularly useful for obtaining the best strategic and economic overview of forest tracks at departmental scale. This theme “land-clearing evaluation method” was selected as a target application for the images derived from the new Pleiades sensors: products and services required by end users. The objective of this work is to assess the real potentiality of such Very High Spatial Resolution (VHSR) imagery for land-clearing management. The methodology used consists in image classification and spatial analysis in order to extract land-clearing quality, and also evaluation of land-clearing quality based on field questionnaires validated through interactions with firefighters and rangers. The development of this methodology and its application to QuickBird images-used as Pleiades data simulations-successfully showed that VHSR Imagery is useful for preventing fire risk. It seems to be a good perspective for providing operational mapping services to help land-clearing management.展开更多
要为明确高密度互通立交行驶环境下,主线车流量对出入口区段驾驶人精神负荷间的影响,在重庆市内环快速路高密度互通立交群进行自然驾驶实车试验,使用Physiolab生理检测仪连续采集驾驶人在行驶过程中的心电数据,用于统计各驾驶人的心率...要为明确高密度互通立交行驶环境下,主线车流量对出入口区段驾驶人精神负荷间的影响,在重庆市内环快速路高密度互通立交群进行自然驾驶实车试验,使用Physiolab生理检测仪连续采集驾驶人在行驶过程中的心电数据,用于统计各驾驶人的心率指标变化情况。本次试验基于主成分分析法选择心率变异率指标RMSSD(root mean square of successive differences)、LFnorm(low frequency norm)、HFnorm(high frequency norm)、LF(low frequency)/HF(high frequency)以及心率突变率指标HRMR(heat ratemutation rate)作为驾驶人精神负荷的评价指标,记为主成分F 1和主成分F 2,并建立评价模型。结果表明:驾驶人在小净距立交出入口区段行驶时,立交主线车流量的大小会影响驾驶人的精神负荷;当驾驶人驶入立交主线时,三次模型对入口段车流量与主成分F 2的拟合效果最好,呈开口向上的三次曲线,曲线谷值点出现在2级流量水平处,模型显著;当驾驶人驶出立交主线时,一次线性模型对出口段车流量与主成分F 1的拟合效果最好,模型显著。展开更多
文摘This paper presents the global solar radiation (GSR) and cloud transmittance factor (cf) measured at the horizontal surface over a period of one year from 2009 to 2010 using CMP6 Pyranometer and NILUUV Irradiance Meter at Lukla (Latitude 26.69oN,Longitude 86.73?E and Altitude 2850 m) in the foothills of the Mt Everest (8850 m high). Monthly and seasonal variations of global solar radiation as well as correlation between clearness index and cloud transmittance factor at Lukla are presented. The annual average daily global solar radiation is about 3.83 kWh/sq·m/day which is sufficient to promote solar active and passive energy technology at high mountain terrain where there is no other viable alternative sources of energy. The maximum and minimum global solar radiation of 5.33 and 2.08 kWh/sq·m/day is recorded in April and September 2010 respectively. The seasonal variation of solar energy is about 2.87 kWh/sq·m/day and 4.83 kWh/sq·m/day in summer and spring respectively which is not in line with the general trend. The coefficient of determination (R2) between cloud transmittance factor (cf) and clearness factor (K) is found to be 0.97. This novel result can be utilized to estimate the global solar radiation at the horizontal surface where K and cf are available.
文摘Every year, the French Mediterranean area is subject to wildland fires. The prevention policy promotes the major role of forest layout, for which it is necessary to build appropriate facilities such as reducing ignition and fire propagation risks near the borders of roads and tracks, creating forest tracks to allow firefighters to move safely through the forest during a fire, creating fuel breaks in order to divide up forests and limit the propagation of fire. Land-clearing along a forest track consists in creating discontinuity between the herbaceous stratum and the tree stratum by eliminating the shrubby stratum and cutting tree crowns. It avoids fire propagation by convection, and enables firefighters to deal with the fire in safety. The main difficulty for forest officers is to identify an optimized method to select appropriate tracks to clear, because it is impossible to clear all the tracks each year. Remote sensing tools would seem to be particularly useful for obtaining the best strategic and economic overview of forest tracks at departmental scale. This theme “land-clearing evaluation method” was selected as a target application for the images derived from the new Pleiades sensors: products and services required by end users. The objective of this work is to assess the real potentiality of such Very High Spatial Resolution (VHSR) imagery for land-clearing management. The methodology used consists in image classification and spatial analysis in order to extract land-clearing quality, and also evaluation of land-clearing quality based on field questionnaires validated through interactions with firefighters and rangers. The development of this methodology and its application to QuickBird images-used as Pleiades data simulations-successfully showed that VHSR Imagery is useful for preventing fire risk. It seems to be a good perspective for providing operational mapping services to help land-clearing management.
文摘要为明确高密度互通立交行驶环境下,主线车流量对出入口区段驾驶人精神负荷间的影响,在重庆市内环快速路高密度互通立交群进行自然驾驶实车试验,使用Physiolab生理检测仪连续采集驾驶人在行驶过程中的心电数据,用于统计各驾驶人的心率指标变化情况。本次试验基于主成分分析法选择心率变异率指标RMSSD(root mean square of successive differences)、LFnorm(low frequency norm)、HFnorm(high frequency norm)、LF(low frequency)/HF(high frequency)以及心率突变率指标HRMR(heat ratemutation rate)作为驾驶人精神负荷的评价指标,记为主成分F 1和主成分F 2,并建立评价模型。结果表明:驾驶人在小净距立交出入口区段行驶时,立交主线车流量的大小会影响驾驶人的精神负荷;当驾驶人驶入立交主线时,三次模型对入口段车流量与主成分F 2的拟合效果最好,呈开口向上的三次曲线,曲线谷值点出现在2级流量水平处,模型显著;当驾驶人驶出立交主线时,一次线性模型对出口段车流量与主成分F 1的拟合效果最好,模型显著。
