期刊文献+
共找到4篇文章
< 1 >
每页显示 20 50 100
《墨经》中的光学思想
1
作者 李质勇 《枣庄学院学报》 2006年第2期31-35,共5页
《墨经》中有八条关于光学的命题,这八条中的前五条记述了影的生成及有关规律.特别是其中的第三条描述了针孔成像实验,并用射箭的飞行来比喻光的直线传播.这是世界上最早的针孔成像实验,也是对光的直线传播特性的最早认识.八条中的后三... 《墨经》中有八条关于光学的命题,这八条中的前五条记述了影的生成及有关规律.特别是其中的第三条描述了针孔成像实验,并用射箭的飞行来比喻光的直线传播.这是世界上最早的针孔成像实验,也是对光的直线传播特性的最早认识.八条中的后三条叙述了反射(平面、凹面、凸面)镜成像现象.其思想非常丰富与深刻. 展开更多
关键词 景(影 即像) 端(点) ( 即镜)
下载PDF
Sex Determination Mechanisms in Fish 被引量:2
2
作者 ZHANG Quanqi SUN Xiaohua QI Jie WANG Zhigang WANG Xinglian WANG Xubo ZHAI Teng 《Journal of Ocean University of China》 SCIE CAS 2009年第2期155-160,共6页
In fish,sex determination(SD) system shows high variation. The SD mechanisms include environmental and genetic regulation. The research on SD system and related genes in intensively studied fish species was reviewed. ... In fish,sex determination(SD) system shows high variation. The SD mechanisms include environmental and genetic regulation. The research on SD system and related genes in intensively studied fish species was reviewed. Although some genes have been described as sex-related,only DMRT1bY can be considered as a master sex determination gene and none of them has been utilized in aquaculture. The variation of fish SD system,the importance of sex-related genes in evolution research and the relations between environmental factors and sex-related genes were also discussed. The fish sex determination mechanism remains largely unknown. Further research needs to be done considering the significance of fish SD studies in basic and applied aspects. 展开更多
关键词 sex determination environmental factors sex-related gene FISH
下载PDF
An Improved Sensor Fault Diagnosis Scheme Based on TA-LSSVM and ECOC-SVM 被引量:10
3
作者 GU Xiaodan DENG Fang +1 位作者 GAO Xin ZHOU Rui 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2018年第2期372-384,共13页
Monitoring the operational state of sensors promptly and the accurate diagnosis of faults are essential. This paper proposes an improved fault diagnosis scheme for sensors, which includes both fault detection and faul... Monitoring the operational state of sensors promptly and the accurate diagnosis of faults are essential. This paper proposes an improved fault diagnosis scheme for sensors, which includes both fault detection and fault identification. Firstly, trend analysis combined with least squares support vector machine(TA-LSSVM) method is proposed and implemented to detect faults. Secondly, an improved error correcting output coding-support vector machine(ECOC-SVM) based fault identification method is proposed to distinguish different sensor failure modes. To demonstrate the effectiveness of the proposed scheme, experiments are conducted with an MTi-series sensor, and some comparisons are made with other fault identification methods. The experimental results demonstrate that the proposed fault diagnosis scheme offers an essential improvement with detection real-time property and better identification accuracy. 展开更多
关键词 ECOC fault detection fault identification SVM TA.
原文传递
A novel multimode process monitoring method integrating LDRSKM with Bayesian inference
4
作者 Shi-jin REN Yin LIANG +1 位作者 Xiang-jun ZHAO Mao-yun YANG 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2015年第8期617-633,共17页
A local discriminant regularized soft k-means (LDRSKM) method with Bayesian inference is proposed for multimode process monitoring. LDRSKM extends the regularized soft k-means algorithm by exploiting the local and n... A local discriminant regularized soft k-means (LDRSKM) method with Bayesian inference is proposed for multimode process monitoring. LDRSKM extends the regularized soft k-means algorithm by exploiting the local and non-local geometric information of the data and generalized linear discriminant analysis to provide a better and more meaningful data partition. LDRSKM can perform clustering and subspace selection simultaneously, enhancing the separability of data residing in different clusters. With the data partition obtained, kernel support vector data description (KSVDD) is used to establish the monitoring statistics and control limits. Two Bayesian inference based global fault detection indicators are then developed using the local monitoring results associated with principal and residual subspaces. Based on clustering analysis, Bayesian inference and manifold learning methods, the within and cross-mode correlations, and local geometric information can be exploited to enhance monitoring performances for nonlinear and non-Gaussian processes. The effectiveness and efficiency of the proposed method are evaluated using the Tennessee Eastman benchmark process. 展开更多
关键词 Multimode process monitoring Local discriminant regularized soft k-means clustering Kernel support vector datadescription Bayesian inference Tennessee Eastman process
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部