An effective Dynamic Moire method was presented to determine the critical time of crack instable propagation in rock dynamic fracture. Two pieces of grating were installed near the notch of Short Rod specimen to form ...An effective Dynamic Moire method was presented to determine the critical time of crack instable propagation in rock dynamic fracture. Two pieces of grating were installed near the notch of Short Rod specimen to form the Moire fringes, then the COD versus time could be monitored from the movement of the Moire fringes, and finally the critical time could be determined from the velocity of COD. This method was also compared with another one.It could be concluded that the critical time determined by Dynamic Moire method corresponds with that of the Transmitted Wave method at the loading rates from 103 to 104 MPa·m(1/2)·S(-1).展开更多
得益于日趋完善的状态监测系统,抽水蓄能电站记录了海量机组运行信息,为开展抽蓄机组劣化趋势评估提供了可靠的数据保障。为此,提出了一种基于Optuna-CatBoost和CRITIC(Criteria Importance though Intercrieria Correlation)评价法的...得益于日趋完善的状态监测系统,抽水蓄能电站记录了海量机组运行信息,为开展抽蓄机组劣化趋势评估提供了可靠的数据保障。为此,提出了一种基于Optuna-CatBoost和CRITIC(Criteria Importance though Intercrieria Correlation)评价法的水电机组劣化评估方法。首先利用最大互信息系数(Maximal Information Coefficient)筛选出机组关键工况系数;然后利用Optuna对CatBoost进行参数寻优,建立Optuna-CatBoost水电机组劣化趋势评估模型;最后基于CRITIC评价法对各通道劣化序列客观赋权,生成机组整机劣化序列。试验结果表明,所提模型的精度优于其他对比模型,能很好地反映机组整机劣化趋势。展开更多
Non-pillar continuous mining(NPCM) is regarded as a high-efficient, high-level and one-step mining technology, which can be divided into two substopes. Back fill stability status in substope I, which directly influenc...Non-pillar continuous mining(NPCM) is regarded as a high-efficient, high-level and one-step mining technology, which can be divided into two substopes. Back fill stability status in substope I, which directly influence the loss rate and dilution rate, etc, will determine whether the experimental research is successful or not. By employing energy method of limit analysis and finite element numerical simulation method, the critical backfill height was determined under the prerequisite condition of its stability, which put forward theoretical basis for reasonable and correct selection of backfill’s parameters. The result showed that the first backfill could not keep stable for NPCM, while the other was able to.展开更多
目前,舰船目标威胁评价采用的加法组合权重主观性过强而乘法组合权重结果存在放大效应,同时权重合理性没有依据具有最终客观说服力的火力打击效果来进行分析。针对以上问题,本文分析了舰船作战新武器及其威胁,增加了俯仰角和翻滚角属性...目前,舰船目标威胁评价采用的加法组合权重主观性过强而乘法组合权重结果存在放大效应,同时权重合理性没有依据具有最终客观说服力的火力打击效果来进行分析。针对以上问题,本文分析了舰船作战新武器及其威胁,增加了俯仰角和翻滚角属性并改进了威胁量化函数,提出了2种基于博弈的组合赋权方法,并采用TOPSIS(Technique for Order Preference by Similarity to an Ideal Solution)方法进行目标威胁排序。通过多波次火力攻防仿真结果表明,提出的博弈组合赋权方法大幅提高了摧毁蓝方的武器单元数量和总毁伤百分比,同时2种博弈方法具有相同的目标威胁排序和蓝方毁伤效果,显示出博弈方法的客观性、优越性和稳定性,可为指挥决策提供更好的参考方案。展开更多
With the rapid development of economy and the intensification of market competition, project management involves various aspects of social development. The limitations of traditional project scheduling management meth...With the rapid development of economy and the intensification of market competition, project management involves various aspects of social development. The limitations of traditional project scheduling management methods are becoming more and more obvious. It is extremely urgent to create and apply new management technologies. According to the constraint theory, critical chain method is a method of controlling a project, which can greatly shorten the completion period of the project and reduce the cost of the enterprise. Firstly, the shortcomings of traditional project scheduling management methods are analyzed, and the importance of adopting key chain technology is pointed out. Secondly, the content of the basic chain method is summarized. Finally, the problems existing in the application of critical chain method are analyzed.展开更多
针对最小二乘孪生支持向量机受误差值影响大,对噪声样本敏感及核函数、核参数选择困难等问题,提出一种Critic特征加权的多核最小二乘孪生支持向量机(Multi-Kernel Least-Squares Twin Support Vector Machine based on Critic weighted,...针对最小二乘孪生支持向量机受误差值影响大,对噪声样本敏感及核函数、核参数选择困难等问题,提出一种Critic特征加权的多核最小二乘孪生支持向量机(Multi-Kernel Least-Squares Twin Support Vector Machine based on Critic weighted,CMKLSTSVM)分类方法。首先,CMKLSTSVM使用Critic法赋予特征权重,反映不同特征间重要性差异,降低冗余特征及噪声样本影响。其次,根据混合多核学习策略构造了一种新的多核权重系数确定方法。该方法通过基核与理想核间的混合核对齐值判断核函数相似程度,确定权重系数,可以合理地组合多个核函数,最大程度地发挥不同核函数的映射能力。最后,采用加权求和的方式将特征权重与核权重进行统一并构造多核结构,使数据表达更全面,提高模型灵活性。在UCI数据集上的对比实验表明,CMKLSTSVM的分类准确率优于单核结构的SVM(support vector machine)算法,同时在高光谱图像上的对比实验反映了CMKLSTSVM对于包含噪声的真实分类问题的有效性。展开更多
文摘An effective Dynamic Moire method was presented to determine the critical time of crack instable propagation in rock dynamic fracture. Two pieces of grating were installed near the notch of Short Rod specimen to form the Moire fringes, then the COD versus time could be monitored from the movement of the Moire fringes, and finally the critical time could be determined from the velocity of COD. This method was also compared with another one.It could be concluded that the critical time determined by Dynamic Moire method corresponds with that of the Transmitted Wave method at the loading rates from 103 to 104 MPa·m(1/2)·S(-1).
文摘得益于日趋完善的状态监测系统,抽水蓄能电站记录了海量机组运行信息,为开展抽蓄机组劣化趋势评估提供了可靠的数据保障。为此,提出了一种基于Optuna-CatBoost和CRITIC(Criteria Importance though Intercrieria Correlation)评价法的水电机组劣化评估方法。首先利用最大互信息系数(Maximal Information Coefficient)筛选出机组关键工况系数;然后利用Optuna对CatBoost进行参数寻优,建立Optuna-CatBoost水电机组劣化趋势评估模型;最后基于CRITIC评价法对各通道劣化序列客观赋权,生成机组整机劣化序列。试验结果表明,所提模型的精度优于其他对比模型,能很好地反映机组整机劣化趋势。
文摘Non-pillar continuous mining(NPCM) is regarded as a high-efficient, high-level and one-step mining technology, which can be divided into two substopes. Back fill stability status in substope I, which directly influence the loss rate and dilution rate, etc, will determine whether the experimental research is successful or not. By employing energy method of limit analysis and finite element numerical simulation method, the critical backfill height was determined under the prerequisite condition of its stability, which put forward theoretical basis for reasonable and correct selection of backfill’s parameters. The result showed that the first backfill could not keep stable for NPCM, while the other was able to.
文摘目前,舰船目标威胁评价采用的加法组合权重主观性过强而乘法组合权重结果存在放大效应,同时权重合理性没有依据具有最终客观说服力的火力打击效果来进行分析。针对以上问题,本文分析了舰船作战新武器及其威胁,增加了俯仰角和翻滚角属性并改进了威胁量化函数,提出了2种基于博弈的组合赋权方法,并采用TOPSIS(Technique for Order Preference by Similarity to an Ideal Solution)方法进行目标威胁排序。通过多波次火力攻防仿真结果表明,提出的博弈组合赋权方法大幅提高了摧毁蓝方的武器单元数量和总毁伤百分比,同时2种博弈方法具有相同的目标威胁排序和蓝方毁伤效果,显示出博弈方法的客观性、优越性和稳定性,可为指挥决策提供更好的参考方案。
文摘With the rapid development of economy and the intensification of market competition, project management involves various aspects of social development. The limitations of traditional project scheduling management methods are becoming more and more obvious. It is extremely urgent to create and apply new management technologies. According to the constraint theory, critical chain method is a method of controlling a project, which can greatly shorten the completion period of the project and reduce the cost of the enterprise. Firstly, the shortcomings of traditional project scheduling management methods are analyzed, and the importance of adopting key chain technology is pointed out. Secondly, the content of the basic chain method is summarized. Finally, the problems existing in the application of critical chain method are analyzed.
文摘针对最小二乘孪生支持向量机受误差值影响大,对噪声样本敏感及核函数、核参数选择困难等问题,提出一种Critic特征加权的多核最小二乘孪生支持向量机(Multi-Kernel Least-Squares Twin Support Vector Machine based on Critic weighted,CMKLSTSVM)分类方法。首先,CMKLSTSVM使用Critic法赋予特征权重,反映不同特征间重要性差异,降低冗余特征及噪声样本影响。其次,根据混合多核学习策略构造了一种新的多核权重系数确定方法。该方法通过基核与理想核间的混合核对齐值判断核函数相似程度,确定权重系数,可以合理地组合多个核函数,最大程度地发挥不同核函数的映射能力。最后,采用加权求和的方式将特征权重与核权重进行统一并构造多核结构,使数据表达更全面,提高模型灵活性。在UCI数据集上的对比实验表明,CMKLSTSVM的分类准确率优于单核结构的SVM(support vector machine)算法,同时在高光谱图像上的对比实验反映了CMKLSTSVM对于包含噪声的真实分类问题的有效性。
