视频字幕生成(Video Captioning)旨在用自然语言描述视频中的内容,在人机交互、辅助视障人士、体育视频解说等领域具有广泛的应用前景。然而视频中复杂的时空内容变化增加了视频字幕生成的难度,之前的方法通过提取时空特征、先验信息等...视频字幕生成(Video Captioning)旨在用自然语言描述视频中的内容,在人机交互、辅助视障人士、体育视频解说等领域具有广泛的应用前景。然而视频中复杂的时空内容变化增加了视频字幕生成的难度,之前的方法通过提取时空特征、先验信息等方式提高生成字幕的质量,但在时空联合建模方面仍存在不足,可能导致视觉信息提取不充分,影响字幕生成结果。为了解决这个问题,本文提出一种新颖的时空增强的状态空间模型和Transformer(SpatioTemporal-enhanced State space model and Transformer,ST2)模型,通过引入最近流行的具有全局感受野和线性的计算复杂度的Mamba(一种状态空间模型),增强时空联合建模能力。首先,通过将Mamba与Transformer并行结合,提出空间增强的状态空间模型(State Space Model,SSM)和Transformer(Spatial enHanced State space model and Transformer module,SH-ST),克服了卷积的感受野问题并降低计算复杂度,同时增强模型提取空间信息的能力。然后为了增强时间建模,我们利用Mamba的时间扫描特性,并结合Transformer的全局建模能力,提出时间增强的SSM和Transformer(Temporal enHanced State space model and Transformer module,TH-ST)。具体地,我们对SH-ST产生的特征进行重排序,从而使Mamba以交叉扫描的方式增强重排序后特征的时间关系,最后用Transformer进一步增强时间建模能力。实验结果表明,我们ST2模型中SH-ST和TH-ST结构设计的有效性,且在广泛使用的视频字幕生成数据集MSVD和MSR-VTT上取得了具有竞争力的结果。具体的,我们的方法分别在MSVD和MSR-VTT数据集上的绝对CIDEr分数超过最先进的结果6.9%和2.6%,在MSVD上的绝对CIDEr分数超过了基线结果4.9%。展开更多
目的:通过氯化锂–毛果芸香碱建立大鼠癫痫持续状态模型,探究癫痫持续状态大鼠模型中不同时间点VEGF的表达变化,并探讨蒙药朝伦雄胡-5对VEGF表达的影响。方法:第一部分:选取90只6~8周龄健康雄性SD大鼠,随机分为造模成功组、给药对照组...目的:通过氯化锂–毛果芸香碱建立大鼠癫痫持续状态模型,探究癫痫持续状态大鼠模型中不同时间点VEGF的表达变化,并探讨蒙药朝伦雄胡-5对VEGF表达的影响。方法:第一部分:选取90只6~8周龄健康雄性SD大鼠,随机分为造模成功组、给药对照组和生理盐水对照组,每组30只。造模成功组与给药对照组通过腹腔注射氯化锂–毛果芸香碱制作大鼠癫痫持续状态模型,生理盐水对照组给予同等剂量的生理盐水处理,造模完成后应用qRT-PCR和Western blot方法检测VEGF转录水平及蛋白水平的表达情况。第二部分:选取40只6~8周龄健康雄性SD大鼠,随机分为蒙药组和对照组。制作癫痫大鼠模型前3 d,蒙药组给予蒙药朝伦雄胡-5灌胃处理,对照组给予同等剂量的生理盐水灌胃,3 d后对蒙药组和对照组通过腹腔注射氯化锂–毛果芸香碱制作大鼠癫痫持续状态模型。造模完成后应用qRT-PCR和Western blot方法检测VEGF转录水平及蛋白水平的表达情况。结果:第一部分:造模成功组VEGF mRNA表达较给药对照组和生理盐水对照组相比显著升高(P Objective: To explore the changes in VEGF expression at different time points in the rat model of status epilepticus by lithium chloride-rutin and explore the effect of Mongolian medicine Zhaolun Xionghu-5 on VEGF expression. Methods: Part I: 90 healthy male rats aged 6~8 weeks were randomly divided into successful modeling group, drug administration control group and normal saline control group, with 30 rats in each group. The rats in the successful modeling group and the control group were intraperitoneally injected with lithium chloride-rutin to establish the rat model of status epilepticus. The rats in the normal saline control group were treated with the same dose of normal saline. After the modeling, qRT-PCR and Western blot were used to detect the expression of VEGF transcription and protein levels. Part II: 40 healthy male rats aged 6~8 weeks were randomly divided into Mongolian medicine group and control group. Three days before the establishment of the rat model of status epilepticus, the Mongolian medicine group was given Mongolian medicine Zholun Xionghu-5 by gavage, and the control group was given the same dose of normal saline by gavage. Three days later, the Mongolian medicine group and the control group were intraperitoneally injected with lithium chloride-rutin to establish the rat model of status epilepticus. After the modeling, qRT-PCR and Western blot were used to detect the expression of VEGF transcription and protein levels. Results: Part I: The mRNA expression of VEGF in the successful modeling group was significantly higher than that in the administration control group and the normal saline control group (P < 0.05). There was no significant difference in VEGF mRNA expression between the administration control group and the normal saline control group. Moreover, VEGF mRNA in the successful modeling group increased gradually with the increase of time, while VEGF mRNA in the administration control group and normal saline control group did not change with time. Compared with the other two groups, the protein expression of VEGF in the successful modeling group was significantly increased (P < 0.05). There was no significant difference in VEGF protein expression between the administration control group and the normal saline control group. Moreover, the changes in VEGF protein in the three groups were no time dependence. Part II: Compared with the control group, the expression of VEGF mRNA in the Mongolian medicine group was significantly decreased (P < 0.05), and with the growth of time, VEGF continued to decrease;the expression of VEGF protein in Mongolian medicine group was significantly lower than that in successful modeling group (P < 0.05), but there was no time dependence. Conclusion: 1) VEGF mRNA expression was increased in hippocampus of rats with status epilepticus induced by lithium chloride-rutin. 2) The expression of VEGF protein in hippocampus of rats with status epilepticus induced by lithium chlorine-rutin was increased. 3) Mongolian medicine Zhaolun Xionghu-5 can induce the decrease of VEGF mRNA expression in hippocampus of rats with status epilepticus, and it decreases with time. 4) Mongolian medicine Zhaolun Xionghu-5 can partially inhibit elevated VEGF expression at the protein level in the model of status epilepticus.展开更多
基于移相加占空比控制策略的三有源桥TAB(triple active bridge)DC-DC变换器具有效率高和软开关范围可扩展等优点,但其小信号建模过程复杂、闭环控制环路参数整定困难。针对该问题,提出1种TAB工作在移相加占空比控制下的全阶连续广义状...基于移相加占空比控制策略的三有源桥TAB(triple active bridge)DC-DC变换器具有效率高和软开关范围可扩展等优点,但其小信号建模过程复杂、闭环控制环路参数整定困难。针对该问题,提出1种TAB工作在移相加占空比控制下的全阶连续广义状态平均建模和PI控制器设计方法。首先,分析TAB的运行原理和Y型等效结构;然后,结合移相加占空比控制的特点和交流方波源等效方法,推导出TAB的广义状态空间平均模型;接着,在推得模型的基础上求得输入到输出的传递函数,设计出PI控制器参数。最后,结合数字仿真及样机实验验证了所提方法的正确性及有效性。展开更多
固态变压器(solid state transformer,SST)在新型电力系统中的应用逐渐增加,因其复杂的拓扑结构、节点数多、子模块内开关频率高等特点,使得面向SST的电磁暂态仿真计算效率低,目前针对SST大步长仿真方法的研究较少。为此,提出一种基于...固态变压器(solid state transformer,SST)在新型电力系统中的应用逐渐增加,因其复杂的拓扑结构、节点数多、子模块内开关频率高等特点,使得面向SST的电磁暂态仿真计算效率低,目前针对SST大步长仿真方法的研究较少。为此,提出一种基于离散状态空间小步合成的SST大步长仿真方法。首先,建立小步长建模、小步长仿真的离散状态空间模型;然后,根据离散状态空间方程的特点,采用小步迭代合成法构建离散状态空间大步长仿真模型,从而实现小步长建模、大步长仿真;最后,给出大步长仿真模型的二次等效方法,减少系统整体建模的系数矩阵维度,降低计算复杂度。结果表明,所提方法不仅能减少数值积分误差和电力电子开关动作误差,实现100 k Hz开关频率下SST换流系统的精确仿真,还能显著提升SST的仿真效率。展开更多
文摘视频字幕生成(Video Captioning)旨在用自然语言描述视频中的内容,在人机交互、辅助视障人士、体育视频解说等领域具有广泛的应用前景。然而视频中复杂的时空内容变化增加了视频字幕生成的难度,之前的方法通过提取时空特征、先验信息等方式提高生成字幕的质量,但在时空联合建模方面仍存在不足,可能导致视觉信息提取不充分,影响字幕生成结果。为了解决这个问题,本文提出一种新颖的时空增强的状态空间模型和Transformer(SpatioTemporal-enhanced State space model and Transformer,ST2)模型,通过引入最近流行的具有全局感受野和线性的计算复杂度的Mamba(一种状态空间模型),增强时空联合建模能力。首先,通过将Mamba与Transformer并行结合,提出空间增强的状态空间模型(State Space Model,SSM)和Transformer(Spatial enHanced State space model and Transformer module,SH-ST),克服了卷积的感受野问题并降低计算复杂度,同时增强模型提取空间信息的能力。然后为了增强时间建模,我们利用Mamba的时间扫描特性,并结合Transformer的全局建模能力,提出时间增强的SSM和Transformer(Temporal enHanced State space model and Transformer module,TH-ST)。具体地,我们对SH-ST产生的特征进行重排序,从而使Mamba以交叉扫描的方式增强重排序后特征的时间关系,最后用Transformer进一步增强时间建模能力。实验结果表明,我们ST2模型中SH-ST和TH-ST结构设计的有效性,且在广泛使用的视频字幕生成数据集MSVD和MSR-VTT上取得了具有竞争力的结果。具体的,我们的方法分别在MSVD和MSR-VTT数据集上的绝对CIDEr分数超过最先进的结果6.9%和2.6%,在MSVD上的绝对CIDEr分数超过了基线结果4.9%。
文摘目的:通过氯化锂–毛果芸香碱建立大鼠癫痫持续状态模型,探究癫痫持续状态大鼠模型中不同时间点VEGF的表达变化,并探讨蒙药朝伦雄胡-5对VEGF表达的影响。方法:第一部分:选取90只6~8周龄健康雄性SD大鼠,随机分为造模成功组、给药对照组和生理盐水对照组,每组30只。造模成功组与给药对照组通过腹腔注射氯化锂–毛果芸香碱制作大鼠癫痫持续状态模型,生理盐水对照组给予同等剂量的生理盐水处理,造模完成后应用qRT-PCR和Western blot方法检测VEGF转录水平及蛋白水平的表达情况。第二部分:选取40只6~8周龄健康雄性SD大鼠,随机分为蒙药组和对照组。制作癫痫大鼠模型前3 d,蒙药组给予蒙药朝伦雄胡-5灌胃处理,对照组给予同等剂量的生理盐水灌胃,3 d后对蒙药组和对照组通过腹腔注射氯化锂–毛果芸香碱制作大鼠癫痫持续状态模型。造模完成后应用qRT-PCR和Western blot方法检测VEGF转录水平及蛋白水平的表达情况。结果:第一部分:造模成功组VEGF mRNA表达较给药对照组和生理盐水对照组相比显著升高(P Objective: To explore the changes in VEGF expression at different time points in the rat model of status epilepticus by lithium chloride-rutin and explore the effect of Mongolian medicine Zhaolun Xionghu-5 on VEGF expression. Methods: Part I: 90 healthy male rats aged 6~8 weeks were randomly divided into successful modeling group, drug administration control group and normal saline control group, with 30 rats in each group. The rats in the successful modeling group and the control group were intraperitoneally injected with lithium chloride-rutin to establish the rat model of status epilepticus. The rats in the normal saline control group were treated with the same dose of normal saline. After the modeling, qRT-PCR and Western blot were used to detect the expression of VEGF transcription and protein levels. Part II: 40 healthy male rats aged 6~8 weeks were randomly divided into Mongolian medicine group and control group. Three days before the establishment of the rat model of status epilepticus, the Mongolian medicine group was given Mongolian medicine Zholun Xionghu-5 by gavage, and the control group was given the same dose of normal saline by gavage. Three days later, the Mongolian medicine group and the control group were intraperitoneally injected with lithium chloride-rutin to establish the rat model of status epilepticus. After the modeling, qRT-PCR and Western blot were used to detect the expression of VEGF transcription and protein levels. Results: Part I: The mRNA expression of VEGF in the successful modeling group was significantly higher than that in the administration control group and the normal saline control group (P < 0.05). There was no significant difference in VEGF mRNA expression between the administration control group and the normal saline control group. Moreover, VEGF mRNA in the successful modeling group increased gradually with the increase of time, while VEGF mRNA in the administration control group and normal saline control group did not change with time. Compared with the other two groups, the protein expression of VEGF in the successful modeling group was significantly increased (P < 0.05). There was no significant difference in VEGF protein expression between the administration control group and the normal saline control group. Moreover, the changes in VEGF protein in the three groups were no time dependence. Part II: Compared with the control group, the expression of VEGF mRNA in the Mongolian medicine group was significantly decreased (P < 0.05), and with the growth of time, VEGF continued to decrease;the expression of VEGF protein in Mongolian medicine group was significantly lower than that in successful modeling group (P < 0.05), but there was no time dependence. Conclusion: 1) VEGF mRNA expression was increased in hippocampus of rats with status epilepticus induced by lithium chloride-rutin. 2) The expression of VEGF protein in hippocampus of rats with status epilepticus induced by lithium chlorine-rutin was increased. 3) Mongolian medicine Zhaolun Xionghu-5 can induce the decrease of VEGF mRNA expression in hippocampus of rats with status epilepticus, and it decreases with time. 4) Mongolian medicine Zhaolun Xionghu-5 can partially inhibit elevated VEGF expression at the protein level in the model of status epilepticus.
文摘基于移相加占空比控制策略的三有源桥TAB(triple active bridge)DC-DC变换器具有效率高和软开关范围可扩展等优点,但其小信号建模过程复杂、闭环控制环路参数整定困难。针对该问题,提出1种TAB工作在移相加占空比控制下的全阶连续广义状态平均建模和PI控制器设计方法。首先,分析TAB的运行原理和Y型等效结构;然后,结合移相加占空比控制的特点和交流方波源等效方法,推导出TAB的广义状态空间平均模型;接着,在推得模型的基础上求得输入到输出的传递函数,设计出PI控制器参数。最后,结合数字仿真及样机实验验证了所提方法的正确性及有效性。
文摘固态变压器(solid state transformer,SST)在新型电力系统中的应用逐渐增加,因其复杂的拓扑结构、节点数多、子模块内开关频率高等特点,使得面向SST的电磁暂态仿真计算效率低,目前针对SST大步长仿真方法的研究较少。为此,提出一种基于离散状态空间小步合成的SST大步长仿真方法。首先,建立小步长建模、小步长仿真的离散状态空间模型;然后,根据离散状态空间方程的特点,采用小步迭代合成法构建离散状态空间大步长仿真模型,从而实现小步长建模、大步长仿真;最后,给出大步长仿真模型的二次等效方法,减少系统整体建模的系数矩阵维度,降低计算复杂度。结果表明,所提方法不仅能减少数值积分误差和电力电子开关动作误差,实现100 k Hz开关频率下SST换流系统的精确仿真,还能显著提升SST的仿真效率。
