http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Qionghua (검색결과 5 건)
- 무료
- 기관 내 무료
- 유료
-
A New Simple Sensorless Control Method for Switched Reluctance Motor Drives
Kai Xin,Qionghua Zhan,Jianwu Luo 대한전기학회 2006 Journal of Electrical Engineering & Technology Vol.1 No.1
In this paper, a new "impedance sensing" method is described. This method overcomes the shortcomings of the impedance sensing method. According to the new method, sensing voltage pulse is applied to the idle phase in the minimum inductance region and the beginning of the increasing inductance region to detect rotor position. The negative torque produced by the sensing voltage pulse can be neglected in the minimum inductance region and the efficiency of SRM is improved. In the minimum inductance region the back electromotive force (EMF) can be neglected. And in the increasing inductance region the EMF opposes the rise of current in the phase, so the position estimation scheme is reliable. Therefore the new "impedance sensing" method is sufficiently precise even under the high back EMF effect. The adjustment of tum-on angle and tum-off angle is also easy to be realized. The technique is very useful in applications where cost or size is primary concerns, such as electric bicycle drives. Experimental results are presented to verify the proposed method.
-
The Research on Prediction Models for Urban Family Member Trip Generation
Shuo Yang,Wei Deng,Qionghua Deng,Pengming Fu 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.7
This paper validates the hypothesis that head of household’s attributes and travel behavior having effects on other family members’ trip frequency in the same household. With using Multinomial Logit Model (MNL) and data source obtained from Resident Trip Survey in Nanjing, 2010, it shows that other family members’ trip frequency are much more relative to head of household’s. Therefore, we propose an idea that investigates the potential possibility of using Multinomial Logit model (MNL) and Support Vector Machine (SVM) to predict other family members’ trip frequency with household’s information. By comparing the prediction accuracy, it is found that the SVM only slightly performs better on overall average accuracy. Then a modified SVM model with significant variables estimated by MNL model is given. The results report that, modified SVM model not only performs better on overall average accuracy than general SVM model and MNL model, but significantly improves partial average accuracy compared with general SVM model. However, the modified SVM still expectedly has a poor performance on predicting for small proportion samples. In the end, some possible improvements are discussed as well as expectation for further studies.
-
A New Simple Sensorless Control Method for Switched Reluctance Motor Drives
Xin Kai,Zhan Qionghua,Luo Jianwu The Korean Institute of Electrical Engineers 2006 Journal of Electrical Engineering & Technology Vol.1 No.1
In this paper, a new 'impedance sensing' method is described. This method overcomes the shortcomings of the impedance sensing method. According to the new method, sensing voltage pulse is applied to the idle phase in the minimum inductance region and the beginning of the increasing inductance region to detect rotor position. The negative torque produced by the sensing voltage pulse can be neglected in the minimum inductance region and the efficiency of SRM is improved. In the minimum inductance region the back electromotive force (EMF) can be neglected. And in the increasing inductance region the EMF opposes the rise of current in the phase, so the position estimation scheme is reliable. Therefore the new 'impedance sensing' method is sufficiently precise even under the high back EMF effect. The adjustment of turn-on angle and turn-off angle is also easy to be realized. The technique is very useful in applications where cost or size is primary concerns, such as electric bicycle drives. Experimental results are presented to verify the proposed method.
-
Polymer Network Liquid Crystal (PNLC) Lenticular Microlens Array With No Surface Treatment
Wang, Xiahui,Ren, Hongwen,Wang, Qionghua IEEE 2016 Journal of display technology Vol.12 No.8
<P>A polymer network liquid crystal (PNLC) lenticular microlens array with no surface treatment is prepared. Before polymerization, the LC and diacrylate monomers are reoriented with gradient refractive index distribution by a fringing field. After polymerization, the oriented LC is stabilized by the polymer network. The prepared PNLC lenticular microlens array is optically anisotropic. Without surface treatment, the device fabrication is simplified, and it can present almost the same optical performance as the PNLC lenticular microlens with surface treatment. Integrating with a 90 twisted-nematic LC cell, the PNLC lenticular microlens array can be switched between a focusing state and non-focusing state. Such a PNLC lenticular microlens array has potential application in switchable 2D/3D displays.</P>
-
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
