ON TESTING FOR HOMOGENEITY OF THE COVARIANCE N\MATRICES

Zhang, Xiao-Ning,Jing, Ping,Ji, Xiao-Ming 한국전산응용수학회 2001 The Korean journal of computational & applied math Vol.8 No.2

Testing equality of covariance matrix of k populations has long been an interesting issue in statistical inference. To overcome the sparseness of data points in a high-dimensional space and deal with the general cases, we suggest several projection pursuit type statistics. Some results on the limiting distributions of the statistics are obtained. some properties of Bootstrap approximation are investigated. Furthermore, for computational reasons an approximation which is based on Number theoretic method for the statistics is adopted. Several simulation experiments are performed. AMS Subject Classification : 2H15, 62H10, 62G09, 62G10

Adaptive Multiple MPC for a Wind Farm with DFIG

Xiao-ming LI,Xi ZHANG,Zhong-wei LIN,Yu-guang NIU,Ming-yang LI,Noel Vishal Nathan 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.5

For low investment and flexible control, doubly fed induction generator (DFIG) is becoming the dominant type that is been used in the wind farms (WFs) today. The report researches about the rotor-side controller of DFIG where all design is based on the single machine infinite bus (SMIB) model. The interactions between the different generators have not been considered in the SMIB model, and the desired performance cannot be obtained by using the controller based on this model. In this situation, an adaptive decentralized-coordinated multiple model predictive control (ADM-MPC) is proposed. First, the interaction measurement method is developed to obtain the interaction measurement model of DFIG, where the interactions between the different generators have been considered. Next, an adaptive multiple MPC based on the obtained interaction measurement method of DFIG is employed to control the rotor-side converter of DFIG. In order to cope with the stochastic disturbance of wind turbine, the augment state structure is employed to improve the tracking control performance. An artificial neural network (ANN) trained online is employed as a weighting controller to cope with the nonlinearities and large operating range of DFIG. A simple, generic renewable power system (RPS) is used to demonstrate contributions. The results of both dominant eigenvalue analysis and time response simulations are represented to illustrate contributions to system damping and transient stability that the DFIG based WF can make with the proposed ADM-MPC controller.

Patterns of Lymph Node Recurrence after Radical Surgery Impacting on Survival of Patients with pT1-3N0M0 Thoracic Esophageal Squamous Cell Carcinoma

Xiao-li Chen,,Tian-wu Chen,Zhi-jia Fang,Xiao-ming Zhang,Zhen-lin Li,Hang Li,Hong-jie Tang,Li Zhou,Dan Wang,Zishu Zhang 대한의학회 2014 Journal of Korean medical science Vol.29 No.2

The aim of this study was to investigate how patterns of lymph nodes recurrence after radical surgery impact on survival of patients with pT1-3N0M0 thoracic esophageal squamous cell carcinoma. One hundred eighty consecutive patients with thoracic esophageal squamous cell carcinoma underwent radical surgery, and the tumors were staged as pT1-3N0M0 by postoperative pathology. Lymph nodes recurrence was detected with computed tomography 3-120 months after the treatment. The patterns of lymph nodes recurrence including stations, fields and locations of recurrent lymph nodes, and impacts on patterns of survival were statistically analyzed. There was a decreasing trend of overall survival with increasing stations or fields of postoperative lymph nodes involved (all P<0.05). Univariate analysis showed that stations or fields of lymph nodes recurrence, and abdominal or cervical lymph nodes involved were prognostic factors for survival(all P<0.05). Cox analyses revealed that the field was an independent factor (P<0.05, odds ratio=2.73). Lymph nodes involved occurred predominantly in cervix and upper mediastinum (P<0.05). In conclusion, patterns of lymph node recurrence especially the fields of lymph nodes involved are significant prognostic factors for survival of patients with pT1-3N0M0 thoracic esophageal squamous cell carcinoma.

Microscopic Mechanisms and Acoustic Emission Characteristics of Sandy Mudstone under Different Water Saturations

Xiao-ming Sun,Fu-kun Shi,Ming-qun Zhu,Jia-xu Ding,Lin-sen He,Zhi-hu Li,Tong Zhang,Cheng-yu Miao 대한토목학회 2024 KSCE Journal of Civil Engineering Vol.28 No.1

In order to study the damage mechanism of surrounding rocks under water-rock coupling, an experimental study on the microscopic law of water absorption and mechanics of sandy mudstone was carried out in the sandy mudstone stratum of Wanfu coal mine in Shandong, China. The results indicate that the strength of sandy mudstone exhibits three stages of relative softening, rapid softening, and decelerated softening. The speed of water molecules entering the microscopic pore structure was analyzed based on the percentage of water molecules in the pore structure. The acoustic emission energy release process is divided into energy accumulation stage, stable release stage and intense release stage. With the increase of water content saturation,  (Spectral width of the multifractal spectrum) tends to decrease and the distribution of events is gradually uniform. The action of water gradually expands and penetrates the cracks and pores inside the sandy mudstone, which makes f (Frequency of occurrence of the signal) change from negative to positive values.

Knockdown of the olfactory co-receptor Orco impairsmate recognition in Tenebrio molitor (Coleoptera: Tenebrionidae)

Xiao-Ming Liu,Bang-Xian Zhang,Shi-Guang Li,Xiang-Jun Rao,Dong-MingWang,Xiao-Xuan Hu,Su Liu 한국응용곤충학회 2016 Journal of Asia-Pacific Entomology Vol.19 No.2

The yellow mealworm beetle, Tenebrio molitor (Coleoptera: Tenebrionidae), is a common insect pest that damages stored grain. The insect olfactory co-receptor (Orco) is a transmembrane protein localized on the surface of the dendrites of olfactory sensory neurons and plays an essential role in the olfactory perception. In this study, an Orco ortholog (named as Tmol\Orco) inT.molitorwas characterized. The deduced amino acid sequence of Tmol\Orco shared significant high identities with Orcos in other insect species from distinct Orders. Reverse transcription quantitative PCR (RT-qPCR) analysis showed that Tmol\Orco was predominantly expressed in the antennae of both male and female adults, and the difference between male antennae and female antennae was not significant. Double-stranded RNA (dsRNA) directly against the Tmol\Orco mRNA was synthesized and injected into the T. molitor male adults, RT-qPCR results demonstrated that the transcription level of Tmol\Orco was significantly reduced at 6 d after the injection. The mate-seeking behavior of Tmol\Orco-silenced beetles was significantly inhibited. Compare to the control individuals, the percentage of Tmol\Orco-silenced beetles successfully find mateswas significantly decreased and the average time they spent for searching were significantly increased. These results provided first direct evidence that suppression of Tmol\Orco transcription contributes to the decline in mate recognition of T. molitor

Security Relations and Community Building in East Asia : The Rise of China and Community Building in East Asia

( Xiao Ming Zhang ) 경남대학교 극동문제연구소 2006 ASIAN PERSPECTIVE Vol.30 No.3

Association of Six Susceptibility Loci with Prostate Cancer in Northern Chinese Men

Zhang, Yu-Rong,Xu, Yong,Yang, Kuo,Liu, Ming,Wei, Dong,Zhang, Yao-Guang,Shi, Xiao-Hong,Wang, Jian-Ye,Yang, Fan,Wang, Xin,Liang, Si-Ying,Zhao, Cheng-Xiao,Wang, Fei,Chen, Xin,Sun, Liang,Zhu, Xiao-Quan,Zh Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.12

Background/Aim: Six prostate cancer (PCa) susceptibility loci were identified in a genome-wide association study (GWAS) in populations of European decent. However, the associations of these 6 single-nucleotide polymorphisms (SNPs) with PCa has remained tobe clarified in men in Northern China. This study aimed to explore the loci associated with PCa risk in a Northern Chinese population. Methods: Blood samples and clinical information of 289 PCa patients and 288 controls from Beijing and Tianjin were collected. All risk SNPs were genotyped using polymerase chain reaction (PCR)-high resolution melting curve technology and gene sequencing. Associations between PCa and clinical covariates (age at diagnosis, prostate-specific antigen [PSA], Gleason score, tumor stage, and level of aggressiveness) and frequencies of alleles and genotypes of these SNPs were analyzed using genetic statistics. Results: Among the candidate SNPs, 11p15 (rs7127900, A) was associated with PCa risk (P = 0.02, odds ratio [OR] = 1.64, 95% confidence interval [CI] = 1.09-2.46). Genotypes showed differences between cases and controls on 11p15 (rs7127900, A), 11q13 (rs7931342, T), and HNF1B (rs4430796, A) (P = 0.03, P = 0.01, and P = 0.04, respectively). The genotype TG on 11q13 (rs7931342, T) was positively associated with an increased Gleason score (P = 0.04, OR = 2.15, 95% CI = 1.02-4.55). Patients carrying TG on 17q24 (rs1859962, G) were negatively associated with an increased body mass index (BMI) (P = 0.03, OR = 0.44, 95% CI = 0.21-0.92) while those with AG on HNF1B (rs4430796, A) were more likely to have PSA increase (P = 0.002). Conclusion: Our study suggests that 11p15 (rs7127900, A) could be a susceptibility locus associated with PCa in Northern Chinese. Genotype TG on 11q13 (rs7931342, T) could be related to an increased Gleason score, AG on HNF1B (rs4430796, A) could be associated with PSA increase, and TG on 17q24 (rs1859962, G) could be negatively associated with an increased BMI in Chinese men with PCa.

CHINA AND INTER-KOREAN RELATIONS

Zhang, Xiao Ming 경남대학교 극동문제연구소 2002 ASIAN PERSPECTIVE Vol.26 No.3

This article elaborates on China's policy toward the Korean peninsula, especially Beijing's treatment of inter-Korean relations since the June 2000 summit. For the most part, the policy has been remarkably consistent in the post-cold war era as its driving force has been the maintenance of good-neighborly relations with both South and North Korea to ensure the peace, stability, and prosperity of the Korean peninsula. A stable, prosperous Korean peninsula can only help foster a favorable security environment in the Northeast Asian region, a condition most conducive to China's domestic modernization drive.

Pd Nanoparticles Self-Assembled on Fluorine-Modified MWCNTs as Electro-Catalysts for Methanol Electro-Oxidation

Xiao-Feng Zhang,Peng Dong,Ying-Jie Zhang,Xi-Kun Yang,Shu-Biao Xia,Zhen-Hua Jin,Ming-Li Xu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.3

Multi-walled carbon nanotubes (MWCNTs) were modified by hydrogen fluoride (HF) in a simple method. With the help of fluorine, Pd nanoparticles (3.9 nm) synthesized by a one-step photochemical reduction were uniformly self-assembled on the active sites of functionalized MWCNTs and a new catalyst (Pd/HF-MWCNT) was obtained. UV–Vis absorption spectra, transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used. The results demonstrated that –F groups were introduced onto the surface of MWCNTs and C–F chemical bonds were formed. In addition, the electronic structure of Pd was changed. Pd–F coordination bond maybe formed between F atom and Pd atom. Cyclic voltammetry and chronoamperometry tests indicated that electrocatalytic activity of Pd/HF-MWCNTs catalyst for methanol in alkaline medium was about 1.6 times higher than that of the commercial Pd/C (JM) catalyst at the same condition. This new functionalized method has the advantages of simple step and safe operation. It is very significant to improve the wide application of MWCNTs and the commercial development of direct methanol fuel cells (DMFCs).

Part 2. Korea and the Major Powers : China and Inter-Korean Relations

( Xiao Ming Zhang ) 경남대학교 극동문제연구소 2002 The Korean Peninsula in Transition : The Summit an Vol.- No.-