Effects of leadership practices on professional learning communities: the mediating role of trust in colleagues

Xin Zheng,Hongbiao Yin,Yuan Liu,Zheng Ke 서울대학교 교육연구소 2016 Asia Pacific Education Review Vol.17 No.3

The building of professional learning communities has been widely recognized as an effective strategy for schools wanting to improve student performance and enhance teachers’ professional capacity. This study explored the relationship between leadership practices and professional learning communities, with a particular focus on the mediating role of trust in colleagues within the context of mainland China. A total of 215 primary school teachers in a province of southwestern China participated in the study. The results showed that leadership practices and trust in colleagues had positive effects on five factors of professional learning communities, namely a shared sense of purpose, collaborative activity, collective focus on student learning, deprivatized practice, and reflective dialog. Trust in colleagues also mediated the influence of leadership practices on professional learning communities. The implications for facilitating professional learning communities in mainland China are discussed here.

Internal force monitoring design of long span bridges based on ultimate bearing capacity ratios of structural components

Hu, Ke,Xie, Zheng,Wang, Zuo-Cai,Ren, Wei-Xin,Chen, Lei-Ke Techno-Press 2018 Structural monitoring and maintenance Vol.5 No.1

In order to provide a novel strategy for long-span bridge health monitoring system design, this paper proposes a novel ultimate bearing capacity ratios based bridge internal force monitoring design method. The bridge ultimate bearing capacity analysis theories are briefly described. Then, based on the ultimate bearing capacity of the structural component, the component ultimate bearing capacity ratio, the uniformity of ultimate bearing capacity ratio, and the reference of component ultimate bearing capacity ratio are defined. Based on the defined indices, the high bearing components can then be found, and the internal force monitoring system can be designed. Finally, the proposed method is applied to the bridge health monitoring system design of the second highway bridge of Wuhu Yangtze river. Through the ultimate bearing capacity analysis of the bridge in eight load conditions, the high bearing components are found based on the proposed method. The bridge internal force monitoring system is then preliminary designed. The results show that the proposed method can provide quantitative criteria for sensors layout. The monitoring components based on the proposed method are consistent with the actual failure process of the bridge, and can reduce the monitoring of low bearing components. For the second highway bridge of Wuhu Yangtze river, only 59 components are designed to be monitored their internal forces. Therefore, the bridge internal force monitoring system based on the ultimate bearing capacity ratio can decrease the number of monitored components and the cost of the whole monitoring system.

An association study between IL1RAPL2 gene and non-specific mental retardation in Chinese children

Ke-Jin Zhang,Bo He,Ping-Yuan Gong,Xiao-Cai Gao,Zi-Jian Zheng,Shao-Ping Huang,Fu-Chang Zhang 한국유전학회 2010 Genes & Genomics Vol.32 No.2

Non-specific mental retardation (NSMR) is one of common children psychiatric diseases with a high prevalence (1−3%). Here we investigated the association between the genetic variants of IL1RAPL2 gene and NSMR in the children of QinBa region of China. We chose five common SNPs of IL1RAPL2,examined their individual genotype frequencies using the conventional polymerase chain reaction single strand conformation polymorphism (PCR-SSCP) method, and evaluated the association between these genetic polymorphisms and NSMR with the suitable biostatistic software. The allele and genotype distributions of two SNPs (rs5962298 and rs9887672) showed significant differences between the control and NSMR groups (allele: p = 0.020 and 0.017; genotype: p =0.025 for rs9887672 respectively). The distribution differences became more significant in girls, but disappeared in boys, suggesting a gender effect. Taken together, we provide substantial evidence that IL1RAPL2 conferred a NSMR susceptibility to children of Qinba region in China. In future, further work should be carried out to scan mutations and to investigate the specific-gender effect in this gene.

Prognostic Value of C-Reactive Protein in Esophageal Cancer: a Meta-analysis

Zheng, Tian-Liang,Cao, Ke,Liang, Cui,Zhang, Kai,Guo, Hai-Zhou,Li, De-Ping,Zhao, Song Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.19

Background: The classical inflammatory biomarker, C-reactive protein (CRP), has been identified to be related to progression of esophageal cancer. Some research showed that elevated pretreatment serum CRP indicated a poor prognosis, but results have been inconsistent. Materials and Methods: We searched the Medline, Embase and the Cochrane Central Search Library for suitable studies and a meta-analysis of eleven (1,886 patients) was conducted to examine the relationship between elevated serum CRP level and overall survival (OS) in esophageal cancer cases. Moreover, correlation analyses were conducted to assess links between pretreatment serum CRP level and tumor node metastasis (TNM) stage as well as T, N, M grade, respectively. Results: The pooled analysis showed that elevated pretreatment serum CRP level was significantly associated with poorer overall survival (HR 2.09, 95%CI 1.52-2.87, p<0.01). Subgroup analyses were conducted by "country", "cut-off value", "treatment" and "number of patients", and no single factor could alter the result. Elevated pretreatment serum CRP was significantly correlated with more advanced TNM stage and T, N, M grade respectively. Conclusions: Elevated pretreatment serum CRP levels are associated with poorer prognosis in esophageal cancer patients, and could serve as a useful biomarker for outcome prediction.

Calculations of the resonant response of carbon nanotubes to binding of DNA

Zheng, Meng,Eom, Kilho,Ke, Changhong Institute of Physics [etc.] 2009 Journal of Physics. D, Applied Physics Vol.42 No.14

<P>We theoretically study the dynamical response of carbon nanotubes (CNTs) to the binding of DNA in an aqueous environment by considering two major interactions in DNA helical binding to the CNT side surface: adhesion between DNA nucleobases and CNT surfaces and electrostatic interactions between negative charges on DNA backbones. The equilibrium DNA helical wrapping angle is obtained using the minimum potential energy method. Our results show that the preferred DNA wrapping angle in the equilibrium binding to CNT is dependent on both DNA length and DNA base. The equilibrium wrapping angle for a poly(dT) chain is larger than a comparable poly(dA) chain as a result of dT in a homopolymer chain having a higher effective binding energy to CNT than dA. Our results also interestingly reveal a sharp transition in the wrapping angle-DNA length profile for both homopolymers, implying that the equilibrium helical wrapping configuration does not exist for a certain range of wrapping angles. Furthermore, the resonant response of the DNA–CNT complex is analysed based on the variational method with a Hamiltonian which takes into account the CNT bending energy as well as DNA–CNT interactions. The closed-form analytical solution for predicting the resonant frequency of the DNA–CNT complex is presented. Our results show that the hydrodynamic loading on the oscillating CNT in aqueous environments has profound impacts on the resonance behaviour of DNA–CNT complexes. Our results suggest that detection of DNA molecules using CNT resonators based on DNA–CNT interactions through frequency measurements should be conducted in media with low hydrodynamic loading on CNTs. Our theoretical framework provides a fundamental principle for label-free detection using CNT resonators based on DNA–CNT interactions.</P>

Design and torque calculation of permanent magnet eddy current coupling with sinusoidal torque output

Ke Chen,Hongyang Shi,Yajun Guo,Lei Yin,Ziwei Bao,Hongmei Zheng 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.4

Due to its unique characteristic of non-contact torque transmission between its permanent magnetic rotor and conductorrotor, permanent magnet eddy current coupling (PMECC) is preferable in transmitting torque from the outside to the insideof a sealed container, which can effectively avoid the tricky problem of dynamic seals. To mix non-uniform liquid solutionsor gas mixtures in sealed containers more effectively, a sinusoidal torque is also required. Thus, permanent magnet eddy current coupling with a slotted conductor is proposed in this paper, which can adaptively output sinusoidal torque under a real-time load when the input rotational speed is constant. Based on the equivalent magnetic circuit method, an analytical model for calculating torque is proposed. When establishing the equivalent magnetic circuit model of the PMECC, the radial magnetic flux leakage circuit is added to the equivalent magnetic circuit diagram, and the cross-sectional shape of the eddy current region is equivalent to an octagon, which simplifies the torque calculation process. The analytical model is verified by finite element method (FEM) simulation and experiments. According to a comparison, the peak and lowest values of output torque obtained by the experiments, the analytical model, and the FEM simulation are consistent. The output torque waveform obtained by the analytical model and FEM simulation are also consistent.

Damage Mechanisms and Metallic Materials Development in Multiphase Flow

Zheng, Yugui,Liu, Wei,Yao, Zhiming,Ke, Wei 한국부식방식학회 2002 Corrosion Science and Technology Vol.31 No.1

The investigation on the synergistic effects among corrosion, slurry erosion and cavitation erosion has special significance for hydraulic turbines operated in Yangtze River and Yellow River where the high concentration solid particles exist in water. Two typical metallic materials i.e. Cr-Mn-N stainless steel and Ni-Ti shapememory-alloy, and two typical materials used for hydraulic turbines 20SiMn and 0Crl3Ni5Mo as compared materials were selected in order to investigate the roles ofwork-hardening ability and martensitic transformation as well as pseudoelastics in damage mechanism in rnultiphase flow. Both modified rotating disk rig and ultrasonic vibration facility were used to simulate the possible damage mechanism of materials in multiphase flow. The effects of corrosion on cavitation erosion were investigated through adding 3wt% NaCI. The degradation mechanism was analyzed by electrochemical test, SEM observation, hardness and roughness measurement. The results showed that there was a strong synergistic interaction among electrochemical corrosion, slurry erosion and cavitation erosion for 20SiMn in liquid-solid two-phase medium. In contrast, corrosion played little role for OCrl3NiSMo. Cr-Mn-N stainless steel with high Mn content showed better resistance to cavitation erosion and slurry erosion than 0Crl3NiSM0, which was mainly due to its good work-hardening ability as well as strain-induced martensite transformation. The cavitation micro-cracks for Cr-Mn-N stainless steel were parallel to the specimen surface in contrast with OCr13NiSMo whose micro-cracks were perpendicular to the surface. Ni-TI alloy with pseudoelasticity showed excellent resistance to combined interaction of cavitation erosion and slurry erosion.

Eddy Loss Analysis and Parameter Optimization of the WPT System in Seawater

Ke-Han Zhang,Zheng-Biao Zhu,Luo-Na Du,Bao-Wei Song 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.3

Magnetic resonance wireless power transfer (WPT) in the marine environment can be utilized in many applications. However, energy loss in seawater through eddy loss (EL) is another consideration other than WPT in air. Therefore, the effect of system parameters on electric field intensity (EFI) needs to be measured and ELs calculated to optimize such a system. In this paper, the usually complicated analytical expression of EFI is simplified to the product of frequency, current, coil turns, and a coefficient to analyze the eddy current loss (ECL). Moreover, as the calculation of ECL through volume integral is time-consuming, the equivalent eddy loss impedance (EELI) is proposed to help designers determine the optimum parameters quickly. Then, a power distribution model in seawater is conceived based on the introduction of EELI. An optimization flow chart is also proposed according to this power distribution model, from which a prototype system is developed which can deliver 100 W at 90% efficiency with a gap of 30 mm and a frequency of 107.1 kHz.

Multi-constrained Shortest Disjoint Paths for Reliable QoS Routing

Ke Xiong,Zheng-ding Qiu,Yuchun Guo,Hongke Zhang 한국전자통신연구원 2009 ETRI Journal Vol.31 No.5

Finding link-disjoint or node-disjoint paths under multiple constraints is an effective way to improve network QoS ability, reliability, and so on. However, existing algorithms for such scheme cannot ensure a feasible solution for arbitrary networks. We propose design principles of an algorithm to fill this gap, which we arrive at by analyzing the properties of optimal solutions for the multi-constrained link-disjoint path pair problem. Based on this, we propose the link-disjoint optimal multi-constrained paths algorithm (LIDOMPA), to find the shortest link-disjoint path pair for any network. Three concepts, namely, the candidate optimal solution, the contractive constraint vector, and structure-aware non-dominance, are introduced to reduce its search space without loss of exactness. Extensive simulations show that LIDOMPA outperforms existing schemes and achieves acceptable complexity. Moreover, LIDOMPA is extended to the node-disjoint optimal multi-constrained paths algorithm (NODOMPA) for the multi-constrained node-disjoint path pair problem.

Block iterative methods for fuzzy linear systems

Ke Wang,Bing Zheng 한국전산응용수학회 2007 Journal of applied mathematics & informatics Vol.25 No.1