地表温度(Land Surface Temperature,LST)在陆地—大气能量交换等研究中扮演着重要角色。LST随时间变化迅速,且极轨遥感卫星获取的LST的地方太阳时在像元间存在差异,需进行时间归一化以提高LST遥感产品的应用价值。面向MODIS LST产品,基...地表温度(Land Surface Temperature,LST)在陆地—大气能量交换等研究中扮演着重要角色。LST随时间变化迅速,且极轨遥感卫星获取的LST的地方太阳时在像元间存在差异,需进行时间归一化以提高LST遥感产品的应用价值。面向MODIS LST产品,基于FY-4A高时间分辨率的LST产品,引入地表温度日变化模型(DTC),构建了粗细分辨率转换配准方法,提出了基于日变化信息的LST时间归一化模型(Temporal-effect Normalization Model of land surface temperature Based on Diurnal variation information,BDTNM),探讨了时间窗口、归一化时刻与空值情况对模型的影响。利用张掖地区站点实测数据、模拟数据对INA08_2模型和BDTNM模型归一化结果进行验证和评价,结果表明BDTNM方法比INA08_2模型具有更好的稳定性及鲁棒性,精度提高了0.4~1.0 K,并具有一定的空值插补能力,该方法对其他遥感卫星LST的时间归一化也具有一定的借鉴意义。展开更多
为提高现有基于智能手机加速度传感器的步态身份识别方法的性能,提出一种基于典型步态周期提取的身份识别方法。针对现有方法中存在的周期检测错误和周期间的相位偏差问题,采用形状上下文和线性时间归一化(linear time normalization,L...为提高现有基于智能手机加速度传感器的步态身份识别方法的性能,提出一种基于典型步态周期提取的身份识别方法。针对现有方法中存在的周期检测错误和周期间的相位偏差问题,采用形状上下文和线性时间归一化(linear time normalization,LTN)相结合的方法对步态周期做序列校准匹配,从中提取典型步态周期来表征整个步态,为检测该方法的性能,采集40个志愿者的步态数据,利用1NN分类算法完成身份识别。实验结果表明,SC-LTN算法的平均正确识别率达96%,验证该方法提取的典型周期能有效用于身份识别。展开更多
The theory for measuring the time constant of thermocouple was introduced, and the method for measuring the time constant of NANMAC thermocouple by using dynamic calibration system of transient surface temperature sen...The theory for measuring the time constant of thermocouple was introduced, and the method for measuring the time constant of NANMAC thermocouple by using dynamic calibration system of transient surface temperature sensor was proposed. In this system, static and dynamic calibrations were conducted for infrared detectors and thermocouples, and then both temperature-time curves were obtained. Since the frequency response of infrared detector is superior to that of calibrat- ed thermocouple, the values measured by infrared detectors are taken as true values. Through dividing the values measured with thermocouples by those with infrared detectors, a normalized curve was obtained, based on which the time constant of thermocouple was measured. With this method, the experiments were carried out with NANMAC thermocouple to obtain its time constant. The results show that the method for measuring the time constant is feasible and the dynamic calibration of thermocouples can be achieved at microsecond and millisecond level. This research has a certain reference value for research and application of NANMAC thermocouple temperature sensor.展开更多
文摘地表温度(Land Surface Temperature,LST)在陆地—大气能量交换等研究中扮演着重要角色。LST随时间变化迅速,且极轨遥感卫星获取的LST的地方太阳时在像元间存在差异,需进行时间归一化以提高LST遥感产品的应用价值。面向MODIS LST产品,基于FY-4A高时间分辨率的LST产品,引入地表温度日变化模型(DTC),构建了粗细分辨率转换配准方法,提出了基于日变化信息的LST时间归一化模型(Temporal-effect Normalization Model of land surface temperature Based on Diurnal variation information,BDTNM),探讨了时间窗口、归一化时刻与空值情况对模型的影响。利用张掖地区站点实测数据、模拟数据对INA08_2模型和BDTNM模型归一化结果进行验证和评价,结果表明BDTNM方法比INA08_2模型具有更好的稳定性及鲁棒性,精度提高了0.4~1.0 K,并具有一定的空值插补能力,该方法对其他遥感卫星LST的时间归一化也具有一定的借鉴意义。
文摘为提高现有基于智能手机加速度传感器的步态身份识别方法的性能,提出一种基于典型步态周期提取的身份识别方法。针对现有方法中存在的周期检测错误和周期间的相位偏差问题,采用形状上下文和线性时间归一化(linear time normalization,LTN)相结合的方法对步态周期做序列校准匹配,从中提取典型步态周期来表征整个步态,为检测该方法的性能,采集40个志愿者的步态数据,利用1NN分类算法完成身份识别。实验结果表明,SC-LTN算法的平均正确识别率达96%,验证该方法提取的典型周期能有效用于身份识别。
文摘The theory for measuring the time constant of thermocouple was introduced, and the method for measuring the time constant of NANMAC thermocouple by using dynamic calibration system of transient surface temperature sensor was proposed. In this system, static and dynamic calibrations were conducted for infrared detectors and thermocouples, and then both temperature-time curves were obtained. Since the frequency response of infrared detector is superior to that of calibrat- ed thermocouple, the values measured by infrared detectors are taken as true values. Through dividing the values measured with thermocouples by those with infrared detectors, a normalized curve was obtained, based on which the time constant of thermocouple was measured. With this method, the experiments were carried out with NANMAC thermocouple to obtain its time constant. The results show that the method for measuring the time constant is feasible and the dynamic calibration of thermocouples can be achieved at microsecond and millisecond level. This research has a certain reference value for research and application of NANMAC thermocouple temperature sensor.
