Optimization of Parameters for LCL Filter of Least Square Method Based Three-phase PWM Converter

Zheng, Hong,Liang, Zheng-feng,Li, Meng-shu,Li, Kai The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.4

LCL filters are widely used in three-phase PWM converter for its advantages of small volume, low cost and inhibition of high frequency current harmonic. However, it is difficult to optimize its design because its parameters are mutually influenced while the value of each parameter for LCL filter has impacts on the converter's cost and size. In this paper, the target of optimization is to minimize the parameter values of LCL filter, and an optimization method for parameters of LCL filter of three-phase PWM converter based on least square method is proposed. With this method, a quantitative calculation of the harmonic component of the converter’s side phase voltage is performed first, and then the quantitative relationship between phase voltage harmonics and grid phase current harmonics is analyzed. After that, the attenuation requirement of each harmonic is obtained by taking into account the requirements for each harmonic component of grid current. Then according to the optimization objective, the objective function with minimum harmonic attenuation deviation is established, and least squares method is adopted for three-dimensional global searching of parameters for LCL filter. Thus, the designed harmonic attenuation curve approximates the minimum attenuation requirements, and the optimized LCL filter parameters are obtained. Finally, the effectiveness of the method is verified by the experiments.

Time-oriented Perception of Environmental design

Zheng Shu Yang,Li Yan 국민대학교 동양문화디자인연구소 2010 Journal of Oriental Culture&Design Vol.2 No.1

Time-oriented Perception of Environmental design is based on the foundation of time and space. Following then key perception of environmental esthetics, design puts emphasis on the time-oriented experience. Because of the unique understanding of time and space in Eastem culture, Chinese traditiona1 architecture is the manifestation of this perception.

Effects of miR-155 Antisense Oligonucleotide on Breast Carcinoma Cell Line MDA-MB-157 and Implanted Tumors

Zheng, Shu-Rong,Guo, Gui-Long,Zhai, Qi,Zou, Zhang-Yong,Zhang, Wei Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.4

Diverse studies have shown that miR-155 is overexpressed in different tumor types. However, the precise molecular mechanism of the ectopic expression of miR-155 in breast cancer is still poorly understood. To further explore the role of miR-155 in breast tumorigenesis, we here assessed the influence of miR-155 antisense oligonucleotide (miR-155 ASO) on MDA-MB-157 cell viability and apoptosis in vitro. Furthermore, the effects of inhibitory effects of miR-155 on the growth of xenograft tumors in vivo were determined with performance of immunohistochemistry to detect expression of caspase-3, a pivotal apoptosis regulatory factor, in xenografts. Transfection efficiency detected by laser confocal microscope was higher than 80%. The level of miR-155 expression was significantly decreased (P<0.05) in the cells transfected with miR-155 ASO, compared with that in cells transfected with a negative control. After being transfected with miR-155 ASO, the viability of MDA-MB-157 cells was reduced greatly (P<0.05) and the number of apoptotic cells was increased significantly. Additionally, miR-155 ASO inhibited the growth of transplanted tumor in vivo and significantly increased the expression of caspase-3. Taken together, our study revealed that miR-155 ASO can induce cell apoptosis and inhibit cell proliferation in vitro. Moreover, miR-155 ASO could significantly repress tumor growth in vivo, presumably by inducing apoptosis via caspase-3 up-regulation. These findings provide experimental evidence for using miR-155 as a therapeutic target of breast carcinoma.

Prognostic Impact of Cyclin D1, Cyclin E and P53 on Gastroenteropancreatic Neuroendocrine Tumours

Liu, Shu-Zheng,Zhang, Fang,Chang, Yu-Xi,Ma, Jie,Li, Xu,Li, Xiao-Hong,Fan, Jin-Hu,Duan, Guang-Cai,Sun, Xi-Bin Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.1

Conventional classifications of gastroenteropancreatic neuroendocrine tumours (GEP-NETs) are rather unsatisfactory because of the variation in survival within each subgroup. Molecular markers are being found able to predict patient outcome in more and more tumours. The aim of this study was to characterize the expression of the proteins cyclin D1, cyclin E and P53 in GEP-NETs and assess any prognostic impact. Tumor specimens from 68 patients with a complete follow-up were studied immunohistochemically for cyclin D1, cyclin E and P53 expression. High cyclin D1 and cyclin E immunostaining (${\geq}$ 5% positive nuclei) was found in 48 (71%) and 24 (35%) cases, and high P53 staining (${\geq}$ 10% positive nuclei) in 33 (49%). High expression of P53 was more common in gastric neuroendocrine tumors and related to malignant behavior, being associate with a worse prognosis on univariate analysis (RR=1.9, 95%CI=1.1-3.2). High expression of cyclin E was significantly associated with shorter survival in the univariate analysis (RR=2.0, 95%CI=1.2-3.6) and multivariate analysis (RR=2.1, 95%CI=1.1-4.0). We found no significant correlation between the expression of cyclin D1 and any clinicopathological variables. Our study indicated a prognostic relevance for cyclin E and P53 immunoreactivity. Cyclin E may be an independent prognostic factor from the 2010 WHO Classification which should be evaluated in further studies.

Monitoring the Ecology of Bacillus During Daqu Incubation, a Fermentation Starter, Using Culture-Dependent and Culture-Independent Methods

( Yan Zheng ),( Xiao Wei Zheng ),( Bei Zhong Han ),( Jian Shu Han ),( M J Robert Nout ),( Jing Yu Chen ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.5

Daqu, a traditional fermentation starter, has been used to produce attractively flavored foods such as vinegar and Chinese liquor for thousands of years. Although Bacillus spp. are one of the dominant microorganisms in Daqu, more precise information is needed to reveal why and how Bacillus became dominant in Daqu, and next, to assess the impact of Bacillus sp. on Daqu and its derived products. We combined culture-dependent and culture-independent methods to study the ecology of Bacillus during Daqu incubation. Throughout the incubation, 67 presumptive Bacillus spp. isolates were obtained, 52 of which were confirmed by 16S rDNA sequencing. The identified organisms belonged to 8 Bacillus species: B. licheniformis, B. subtilis, B. amyloliquefaciens, B. cereus, B. circulans, B. megaterium, B. pumilus, and B. anthracis. A primer set specific for Bacillus and related genera was used in a selective PCR study, followed by a nested DGGE PCR targeting the V9 region of the 16S rDNA. Species identified from the PCR-DGGE fingerprints were related to B. licheniformis, B. subtilis, B. amyloliquefaciens, B. pumilus, B. benzoevorans, and B. foraminis. The predominant species was found to be B. licheniformis. Certain B. licheniformis strains exhibited potent antimicrobial activities. The greatest species diversity occurred at the Liangmei stage of Daqu incubation. To date, we lack sufficient knowledge of Bacillus distribution in Daqu. Elucidating the ecology of Bacillus during Daqu incubation would enable the impact of Bacillus on Daqu to be accessed, and the quality and stabilization of Daqu-derived products to be optimized.

중국 국가이미지가 관광지 이미지와 행동의도에 미치는 영향 -잠재적인 한국 관광객을 중심으로-

정수욱 ( Zheng Shu-yu ),송광인 ( Song Gwan-gin ) 한국관광산업학회 2021 Tourism Research Vol.46 No.4

본 연구는 코로나19 사태로 인해 중국의 국가이미지가 관광지 이미지, 행동의도에 어떤 영향을 미치는지 조사하는 것이다. 연구의 목적은 해외 잠재 관광객들의 관광지의 열망에 영향을 미치는 요인과 포스트 코로나 시대의 행동의도를 파악하고자 한다. 이를 진행하기 위해 중국관광지에 관광 경험이 있거나 관광할 예정인 잠재적 한국 관광객을 대상으로 인터넷 설문지를 배포하는 방식으로 설문조사를 실시하였다. 조사기간은 2021년 7월 8일부터 2021년 9월 7일까지 두 달 간 조사를 실시했으며 256부의 설문지를 배포하고, 분석에 적합하지 않은 미 회수된 35부의 설문지를 제외한 221부의 설문지를 실증분석에 활용하였다. 연구결과는 다음과 같다. 첫째, 국가이미지가 관광지 이미지에 유의한 영향을 미치고, 그 중에서 문화적 요인이 가장 현저한 영향을 미친다는 것으로 나타났다. 둘째, 국가이미지는 관광객의 행동 의도에 유의한 영향을 미치고, 그 중에서 문화적 요인, 사회적 요인이 현저한 영향을 미치는 것으로 나타났다. 셋째, 관광지 이미지는 행동의도에 유의한 영향을 미치고, 그 중 정서적 이미지가 현저한 영향을 미치는 것으로 나타났다. The purpose of this study aimed to explore the impact of the Chinese national image behave on the destination image and behavior intention. The purpose of the study is to understand the factors affecting the aspirations of potential overseas tourists and their behavioral intentions in the post COVID-19 era. For fulfill the purposes of this study, potential Korean experienced or prospective tourists intending to visit Chinese tourist attractions were surveyed by the distribution of online questionnaires. The survey lasted from 8 July 2021 to 7 September 2021, and 221 questionnaires except 35 unrecovered questionnaires unsuitable for analysis, 221 were used for empirical analysis. According to the research results: first, it shows that the national image has a significant impact on the image of tourist attractions, among which cultural factors are the most significant impact. Secondly, the national image has a significant impact on the behavior intention of tourists, among which cultural and social factors have a significant influence. Third, the image of tourist attractions has a significant impact on the behavior intention, among which the emotional image has a significant influence.

Electroforming mirochannel metal dies using simple multilayer photoresist moulds

Wen-Shu Zheng,Zhong-Ning Guo,Jun-Feng He,Shu-Zhen Jiang,Yong-Jun Tang,Yong-Jun Zhang 한국생산제조학회 2014 한국생산제조시스템학회 학술발표대회 논문집 Vol.2014 No.9(2)

Incidence, Survival and Prevalence of Esophageal and Gastric Cancer in Linzhou City from 2003 to 2009

Liu, Shu-Zheng,Wang, Bing,Zhang, Fang,Chen, Qiong,Yu, Liang,Cheng, Lan-Ping,Sun, Xi-Bin,Duan, Guang-Cai Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.10

This study describes recent trends in incidence, survival and prevalence of subgroups of esophageal and gastric cancer in Linzhou city between 2003 and 2009. Data of esophageal and gastric cancer for the period of interest were extracted from the Linzhou Cancer Registry. Using information on tumor morphology or anatomical site, data were divided into six groups; esophageal squamous cell carcinoma, esophageal adenocarcinoma, other and unspecified types of esophageal cancer, and cardia, non-cardia, and unspecified anatomical site of stomach cancer. Incidence, survival and prevalence rates for each of the six cancer groups were calculated. The majority of esophageal cancers were squamous cell carcinomas (82%). Cardiac cancer was the major gastric cancer group (64%). The incidence of esophageal squamous cell carcinoma and gastric cardiac cancer increased between 2003 and 2009. Both esophageal and gastric cancer had a higher incidence in males compared with females. Overall survival was poor in all sub-groups with 1 year survival ranging from 45.9 to 65.6% and 5 year survival ranging from 14.7 to 30.5%. Prevalence of esophageal squamous cell carcinoma and gastric cardiac cancer was high (accounting for 80% overall). An increased focus on prevention and early diagnosis, especially in esophageal squamous cell carcinoma and gastric cardiac cancer, is required.

Optimization of Parameters for LCL Filter of Least Square Method Based Three-phase PWM Converter

Hong Zheng,Zheng-feng Liang,Meng-shu Li,Kai Li 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.4

LCL filters are widely used in three-phase PWM converter for its advantages of small volume, low cost and inhibition of high frequency current harmonic. However, it is difficult to optimize its design because its parameters are mutually influenced while the value of each parameter for LCL filter has impacts on the converter"s cost and size. In this paper, the target of optimization is to minimize the parameter values of LCL filter, and an optimization method for parameters of LCL filter of three-phase PWM converter based on least square method is proposed. With this method, a quantitative calculation of the harmonic component of the converter’s side phase voltage is performed first, and then the quantitative relationship between phase voltage harmonics and grid phase current harmonics is analyzed. After that, the attenuation requirement of each harmonic is obtained by taking into account the requirements for each harmonic component of grid current. Then according to the optimization objective, the objective function with minimum harmonic attenuation deviation is established, and least squares method is adopted for three-dimensional global searching of parameters for LCL filter. Thus, the designed harmonic attenuation curve approximates the minimum attenuation requirements, and the optimized LCL filter parameters are obtained. Finally, the effectiveness of the method is verified by the experiments.

ON CONVERGENCE OF THE MODIFIED GAUSS-SEIDEL ITERATIVE METHOD FOR H-MATRIX LINEAR SYSTEM

Miao, Shu-Xin,Zheng, Bing Korean Mathematical Society 2013 대한수학회논문집 Vol.28 No.3

In 2009, Zheng and Miao [B. Zheng and S.-X. Miao, Two new modified Gauss-Seidel methods for linear system with M-matrices, J. Comput. Appl. Math. 233 (2009), 922-930] considered the modified Gauss-Seidel method for solving M-matrix linear system with the preconditioner $P_{max}$. In this paper, we consider the modified Gauss-Seidel method for solving the linear system with the generalized preconditioner $P_{max}({\alpha})$, and study its convergent properties when the coefficient matrix is an H-matrix. Numerical experiments are performed with different examples, and the numerical results verify our theoretical analysis.