3상 6/8극 SRM의 설계 및 운전 특성

ChenHao,이동희,안진우 전력전자학회 2003 전력전자학회 논문지 Vol.8 No.1

The design and analysis of a three-phase 6/8 structure SRM(switched reluctance motor) are described. The range of the stator pole arc and the rotor pole arc of the motor are analyzed in the linear region. The optimum range of the stator pole arc and the turn-off angle of the main switches in the power converter are given with the 2-D finite element electro-magnetic field calculation of the motor and the nonlinear simulation. Test results of the prototype are discussed. This type is good for high efficiency drive because the drive circuit is simple and current density and copper loss of the winding are low. 본 논문은 3상 6/8극 스위치드 릴럭턴스 전동기의 설계 및 특성해석에 대해 다루었다. 고정자와 회전자 극호각의 설계 범위를 해석하고 최적값을 해석하였다. 최적의 값은 선형, 비선형으로 나누어 전통적인 설계접근 방식과 설계용 CAD를 이용하여 해석하였으며 실제 전동기를 제작하여 설계결과를 확인하였다. 이 전동기는 동일한 8/6 SRM에 비해 구동회로가 단순해지며, 권선의 전류밀도와 동손이 감소하여 효율이 상승하는 장점이 있다.

Influence of Hydrogen on Al-doped ZnO Thin Films in the Process of Deposition and Annealing

Chen, Hao,Jin, Hu-Jie,Park, Choon-Bae,Hoang, Geun-C. The Korean Institute of Electrical and Electronic 2009 Transactions on Electrical and Electronic Material Vol.10 No.3

The Al-doped ZnO (AZO) films were deposited on a glass substrate by RF magnetron sputtering in pure Ar and $Ar+H_2$ gas ambient at temperature of $100^{\circ}C$ and annealed in hydrogen ambient at the temperature range from 100 to 300 $^{\circ}C$, respectively. It was found that either the addition of hydrogen to the sputtering gas or the annealing treatment effectively reduced the resistivity of the AZO films. When the AZO films were annealed at the temperature of 300 $^{\circ}C$ for lhr in a hydrogen atmosphere, the resistivity decreased from $2.60{\times}10^{-3}\;{\Omega}cm$ to $8.42{\times}l0^{-4}\;{\Omega}cm$ for the film deposited in pure Ar gas ambient. Under the same annealing conditions of temperature and hydrogen ambient, the resistivity of AZO films deposited in the $Ar+H_2$ gas mixture decreased from $8.22{\times}l0^{-4}\;{\Omega}cm$ to $4.25{\times}l0^{-4}\;{\Omega}cm$. The lowest resistivity of $4.25{\times}l0^{-4}\;{\Omega}cm$ was obtained by adding hydrogen gas to the deposition and annealing process. X-ray diffraction (XRD) pattern of all films showed preferable growth orientation of (002) plane. The average transmittance is above 85 % and in the range of 400-1000 nm for all films.

Active mass damper control for cable stayed bridge under construction: an experimental study

Chen, Hao,Sun, Zhi,Sun, Limin Techno-Press 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.38 No.2

A cable stayed bridge under construction has low structural damping and is not as stable as the completed bridge. Control countermeasures, such as the installation of energy dissipating devices, are thus required. In this study, the general procedure and key issues on adopting an active control device, the active mass damper (AMD), for vibration control of cable stayed bridges under construction were studied. Taking a typical cable stayed bridge as the prototype structure; a lab-scale test structure was designed and fabricated firstly. A baseline FEM model was then setup and updated according to the modal parameters measured from vibration test on the structure. A numerical study to simulate the bridge-AMD control system was conducted and an efficient LQG-based controller was designed. Based on that, an experimental implementation of AMD control of the transverse vibration of the bridge model was performed. The results from numerical simulation and experimental study verified that the AMD-based active control was feasible and efficient for reducing dynamic responses of a complex structural system. Moreover, the discussion made in this study clarified some critical problems which should be addressed for the practical implementation of AMD control on real cable-stayed bridges.

Effective Video Coding algorithm for Substation Video and Environment Surveillance System

Chen, Hao,Gao, Ya The Korean Institute of Electrical Engineers 2014 The Journal of International Council on Electrical Vol.4 No.3

Guangdong Power Grid Corporation has put forward and implemented based on IP network digital, Linux, industrial grade layered architecture of substation video and environment surveillance system. In order to improve video coding efficiency and meet requirements of users on HD images resolution of substation video and environment surveillance system, this paper proposes an improved implicit motion information inter prediction algorithm for P slice in H.264 based on the spatio-temporal adaptive localized learning model. This algorithm essentially takes advantage of the temporal and spatial correlations that may exist within frames at the block level, and reduces the bits required for encoding motion information while retaining or even improving encoding quality. The simulation results show that the proposed algorithm improves encoding efficiency compared with the H.264 standard with 0.10 dB (QCIF) and 0.17 dB (WQVGA) average PSNR gain, with relatively increase in complexity.

Irradiation Application on the Preparation of Emergency Food

Chen Hao 한국식품영양과학회 2011 한국식품영양과학회 학술대회발표집 Vol.2011 No.10

Controlled growth and modification of vertically-aligned carbon nanotubes for multifunctional applications

Chen, Hao,Roy, Ajit,Baek, Jong-Beom,Zhu, Lin,Qu, Jia,Dai, Liming Elsevier 2010 Materials science & engineering. a review journal. Vol.70 No.3

<P><B>Abstract</B></P><P>Vertically-aligned carbon nanotubes possess many advantages for a wide range of multifunctional applications. Along with the controlled growth of aligned/micropatterned carbon nanotubes, surface modification of vertically-aligned carbon nanotubes are essential in order to meet specific requirements demanded for particular applications. While many innovative synthetic methods have been developed for controlled growth of vertically-aligned multiwalled and single-walled carbon nanotubes, various interesting physical and chemical approaches have recently been devised for functionalization of the constituent carbon nanotubes in vertically-aligned carbon nanotube arrays with their alignment being largely retained. In this article, recent developments in the controlled growth and modification of vertically-aligned carbon nanotubes for multifunctional applications are reviewed.</P>

Ingenuity Follows Nature

Chen Hao 한국콘텐츠학회 2013 ICCC International Digital Design Invitation Exhib Vol.2013 No.-

Sensitivity

Chen Hao 한국콘텐츠학회 2013 ICCC International Digital Design Invitation Exhib Vol.2013 No.-

Effects of soft pellet creep feed on pre-weaning and post-weaning performance and intestinal development in piglets

Chen Hao,Wang Chunwei,Wang You,Chen Yilin,Wan Meng,Zhu Jiadong,Zhu Aixia 아세아·태평양축산학회 2021 Animal Bioscience Vol.34 No.4

Objective: This study aimed to determine the effects of soft pellet creep feed (SPCF) on growth performance and intestinal development in piglets. Methods: A total of 18 sows and their litters of crossbred piglets (14±2 days, 3.73±0.72 kg) were assigned to one of three dietary groups receiving i) powder creep feed (PCF), ii) hard pellet creep feed (HPCF) or iii) SPCF during the pre-weaning period. After weaning, piglets were selected for continuous evaluation of the three diets on growth performance and intestinal health. Results: In the pre-weaning period, the average daily feed intake and average daily dry matter intake were significantly higher in the SPCF group than the HPCF group (p<0.05). In the post-weaning and entire experimental period, the different diets had no significant effect on growth performance. At 10 d after weaning, the serum glucose concentration was lower in the SPCF group (p<0.05) than the other groups; a higher (p<0.05) villus height and lower (p<0.05) crypt depth in the jejunum were also observed in the SPCF group than the other groups; Meanwhile, in the duodenum and jejunum, the SPCF group had a higher (p<0.05) villus height to crypt depth ratio than the other groups; Furthermore, the higher (p<0.05) threshold cycle values of lactic acid bacteria and lower (p<0.05) threshold cycle values of Clostridium, Enterobacter and Escherichia coli were also observed in the SPCF group, and the sucrase and maltase activity was higher (p<0.05) in the SPCF group than the other groups in duodenum and ileum. Conclusion: The SPCF improved pre-weaning feed intake and decreased the negative effects of weaning stress in the intestine in piglets. Objective: This study aimed to determine the effects of soft pellet creep feed (SPCF) on growth performance and intestinal development in piglets.Methods: A total of 18 sows and their litters of crossbred piglets (14±2 days, 3.73±0.72 kg) were assigned to one of three dietary groups receiving i) powder creep feed (PCF), ii) hard pellet creep feed (HPCF) or iii) SPCF during the pre-weaning period. After weaning, piglets were selected for continuous evaluation of the three diets on growth performance and intestinal health.Results: In the pre-weaning period, the average daily feed intake and average daily dry matter intake were significantly higher in the SPCF group than the HPCF group (p<0.05). In the post-weaning and entire experimental period, the different diets had no significant effect on growth performance. At 10 d after weaning, the serum glucose concentration was lower in the SPCF group (p<0.05) than the other groups; a higher (p<0.05) villus height and lower (p<0.05) crypt depth in the jejunum were also observed in the SPCF group than the other groups; Meanwhile, in the duodenum and jejunum, the SPCF group had a higher (p<0.05) villus height to crypt depth ratio than the other groups; Furthermore, the higher (p<0.05) threshold cycle values of lactic acid bacteria and lower (p<0.05) threshold cycle values of <i>Clostridium, Enterobacter and Escherichia coli</i> were also observed in the SPCF group, and the sucrase and maltase activity was higher (p<0.05) in the SPCF group than the other groups in duodenum and ileum.Conclusion: The SPCF improved pre-weaning feed intake and decreased the negative effects of weaning stress in the intestine in piglets.

China Consensus Document on Allergy Diagnostics

Chen Hao,Li Jing,Cheng Lei,Gao Zhongshan,Lin Xiaoping,Zhu Rongfei,Yang Lin,Tao Ailin,Hong Haiyu,Tang Wei,Guo Yinshi,Huang Huaiqiu,Sun Jinlyu,Lai He,Lei Cheng,Liu Guanghui,Xiang Li,Chen Zhuanggui,Ma Ha 대한천식알레르기학회 2021 Allergy, Asthma & Immunology Research Vol.13 No.2

The prevalence of allergic diseases has increased dramatically in recent years in China, affecting the quality of life in 40% of the population. The identification of allergens is the key to the diagnosis of allergic diseases. Presently, several methods of allergy diagnostics are available in China, but they have not been standardized. Additionally, cross-sensitization and co-sensitization make allergy diagnostics even more complicated. Based on 4 aspects of allergic disease (mechanism, diagnosis procedures, allergen detection in vivo and in vitro as well as the distribution map of the most important airborne allergens in China) and by referring to the consensus of the European Society of Allergy and Clinical Immunology, the World Allergy Organization, and the important literature on allergy diagnostics in China in recent years, we drafted this consensus of allergy diagnostics with Chinese characteristics. It aims to standardize the diagnostic methods of allergens and provides a reference for health care givers. The current document was prepared by a panel of experts from the main stream of professional allergy associations in China.