Vegetable Genetics and Breeding in China

Hui Feng 한국원예학회 2008 한국원예학회 기타간행물 Vol.- No.-

Responses of Grain Yield and Greenhouse Gases Emission to Different Rice Varieties and Irrigation Managements in a Rice Paddy Field

Huifeng Sun,Sheng Zhou,Xiangfu Song,Guifa Chen,Zishi Fu 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

A Study on the Guarantee Supply of Regional Credit Guarantee Foundations Using Hierarchical Regression: Using Naver Trend & Mediation Effect

Huifeng Pan,Hee-Young Son,Man-Su Kang 보안공학연구지원센터 2016 International Journal of Software Engineering and Vol.10 No.4

The data used in this study includes guarantee-related data from January 2007 to September 2014, as well as data of search volume provided by Naver Trend. As a result of the hierarchical regression analysis, it turned out that in step 1, the volume of credit guarantee searching affected guarantee supply while the default amount did not. In addition, it is expected that as the volume of credit guarantee searching increases, guarantee supply will also be expended. In step 2, it turned out that the amount of default normalization affected guarantee supply. It is expected that as the amount of default normalization increases, guarantee supply will also be expanded. Finally, in step 3, it turned out that both the volume of credit guarantee searching and the amount of default normalization affected guarantee supply while the default amount did not. As for the explanation power of the three models, that of step 1 was 8.3%, that of step 2 was 13.7%, and that of step 3 was 19.3%. As the default amount affected guarantee supply, Sobel Test was conducted to measure the mediation effect of the volume of credit guarantee searching and the amount of default normalization. As a result, it turned out that the volume of credit guarantee searching had mediation effect while the amount of default normalization did not. The objective of this study is to examine the effect of guarantee accidents of the Regional Credit Guarantee Foundation, which provides public finance service on guarantee supply. This indicates the necessity of examining the causality through another regression analysis after a Granger Causality test. In terms of demands for guarantee supply, further research may be necessary on referring to the volume of credit guarantee searching.

A Study on the Switching Intention about Smart Phone: Focusing on Customer Behavior in China

Pan Huifeng,Man-su Kang 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.10

This study examines the effects of perceived value among smart phone users on customer satisfaction, brand trust, brand loyalty, and switching intention in order to analyze the process of purchasing smart phone in China. To this end, a survey was conducted among Xiaomi and Galaxy smart phone users in Shanghai, China. The results show that perceived value had no direct effect on brand loyalty and switching intention, but it turned out that perceived value had indirect effect on brand loyalty through brand trust when the mediating effect was measured. In addition, it turned out that customer satisfaction had direct effects on brand trust while it had no direct effect on brand loyalty and switching intention. Brand trust had direct effects on brand loyalty and switching intention, and it also had indirect effects on switching intention through brand loyalty. It also turned out that brand loyalty had direct effects on switching intention, and that perceived value in the general model of this study had direct effects on brand trust. The mediating effect through customer satisfaction indicates the function of a partial mediating model. Since perceived value had no direct effect on brand loyalty, the mediating effect through brand trust indicates the function of a complete mediating model. Since customer satisfaction had no direct effect on brand loyalty, the mediating effect through brand trust indicates the function of a complete mediating model. It is thought that the findings of this study will contribute to establishing marketing strategies to secure competitive edge among smart phone competitors in China. In addition, if smart phone suppliers in the Chinese market desire basic materials for the establishment of marketing strategies differentiated from those of competitors, the findings of this study can be utilized and helpful for such strategies.

Saturating Composite Disturbance-Observer-Based Control and H∞ Control for Discrete Time-delay Systems with Nonlinearity

Xinjiang Wei,Huifeng Zhang,Lei Guo 제어·로봇·시스템학회 2009 International Journal of Control, Automation, and Vol.7 No.5

This note is concerned with a saturating composite disturbance-observer-based control (DOBC) and H∞ control for a class of discrete time-delay systems with nonlinearity and disturbances. The disturbances are supposed to include two parts. One in the input channel is generated by an exogenous system with uncertainty, which can represent the harmonic signals with modeling perturbations. The other is supposed to have the bounded H₂norm, which can represent parametric uncertainties and external disturbance existing in the controlled object. The design approaches of reduced-order disturbance observer are presented for the estimation of the disturbance. By composite control law with saturation, the disturbances can be rejected and attenuated, simultaneously, the desired dynamic performances can be guaranteed for discrete time-delay systems with known and unknown nonlinear dynamics, respectively. Simulation for a flight control system is provided to show the effectiveness of the proposed scheme compared with the previous schemes.

Experimental Investigation and Mechanism Analysis of Tungsten Disulfide Soft Coated Micro-Nano Textured Self-Lubricating Dry Cutting Tools

Yunsong Lian,Huifeng Chen,Chenliang Mu,Jianxin Deng,Shuting Lei 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.5 No.2

A new dry cutting tool named WS2 soft coated Micro-Nano textured self-lubricating dry cutting tool (WTT tool) is developed and tested. Dry turning tests have been carried out on 45# quenched and tempered steel with a WTT tool and three other types of alternative tools. The machining performance was assessed in terms of the cutting forces, cutting temperature, friction coefficient at the tool-chip interface, chip deformation, tool wear, and the surface roughness of the machined workpiece. The results show that the WTT tool has the best cutting performance among all the tools tested under the same cutting conditions. Through theoretical analysis and experimental results, the mechanisms of the WTT tool in improving cutting performance were put forward. Meanwhile, the effect of Micro-Nano texture and WS2 soft coating on the cutting forces and the cutting temperature is analyzed. It can be concluded that the WTT tool can effectively improve the anti-adhesion and wear-resistance properties and increase the tool life.

Performance of Microtextured Tools Fabricated by Inductively Coupled Plasma Etching in Dry Cutting Tests on Medium Carbon Steel Workpieces

Yunsong Lian,Huifeng Chen,Chenliang Mu 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.6 No.2

Microtextures were successfully fabricated on the rake face of the cemented carbide (WC/TiC/Co) tools through inductively coupled plasma etching technology. Two types of microtextured tools were designed and fabricated. Their performance in cutting the AISI 1045 medium carbon steel was tested and compared to that of conventional non-textured tools. The comparison involved cutting forces, cutting temperature, friction coefficient, tool wear, chip adhesion, and machined workpiece surface roughness. The results show that microtextures on the rake face of the cutting tool can make the cutting process more stable than a conventional non-textured tool, and different textures may be suitable for different ranges of the cutting speed. In the latter range 100–200 m/min, microtextures significantly reduce the cutting force, cutting temperature, friction coefficient at the tool–chip interface, while the anti-adhesion property of textured tools and the surface quality of machined workpieces attain their maximal values. The effectiveness of textures is shown to be affected by chip adhesion and blockage resulting from derivative cutting, which appears at high cutting speeds. Moreover, the violation of the structural integrity of textures and their damage can strongly deteriorate the cutting process at low cutting speeds.

Numerical analysis of the axially loaded concrete filled steel tube columns with debonding separation at the steel-concrete interface

Chen Shiming,Zhang Huifeng 국제구조공학회 2012 Steel and Composite Structures, An International J Vol.13 No.3

The interaction between steel tube and concrete core is the key design considerations for concrete-filled steel tube columns. In a concrete-filled steel tube (CFST) column, the steel tube provides confinement to the concrete core which permits the composite action among the steel tube and the concrete. Due to construction faults and plastic shrinkage of concrete, the debonding separation at the steel-concrete interface weakens the confinement effect, and hence affects the behaviour and bearing capacity of the composite member. This study investigates the axial loading behavior of the concrete filled circular steel tube columns with debonding separation. A three-dimensional nonlinear finite element model of CFST composite columns with introduced debonding gap was developed. The results from the finite element analysis captured successfully the experimental behaviours. The calibrated finite element models were then utilized to assess the influence of concrete strength, steel yield stress and the steel-concrete ratio on the debonding behaviour. The findings indicate a likely significant drop in the load carrying capacity with the increase of the size of the debonding gap. A design formula is proposed to reduce the load carrying capacity with the presence of debonding separation.

An extremum method for bending-wrinkling predictions of inflated conical cantilever beam

Changguo Wang,Zhenyong Du,Huifeng Tan 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.46 No.1

An extremum method is presented to predict the wrinkling characteristics of the inflated cone in bending. The wrinkling factor is firstly defined so as to obtain the wrinkling condition. The initial wrinkling location is then determined by searching the maximum of the wrinkling factor. The critical wrinkling load is finally obtained by determining the ratio of the wrinkling moment versus the initial wrinkling location. The extremum method is proposed based on the assumption of membrane material of beam wall, and it is extended to consider beam wall with thin-shell material in the end. The nondimensional analyses show that the initial wrinkling location is closely related to the taper ratio. When the taper ratio is higher than the critical value, the initial wrinkles will be initiated at a different location. The nondimensional critical wrinkling load nonlinearly increases as the taper ratio increases firstly, and then linearly increases after the critical taper ratio. The critical taper ratio reflects the highest load-carrying efficiency of the inflated cone in bending, and it can be regarded as a measure to optimize the geometry of the inflated cone. The comparative analysis shows fairly good agreement between analytical and numerical results. Over the whole range of the comparison, the mean differences are lower than 3%. This gives confidence to use extremum method for bending-wrinkling analysis of inflated conical cantilever beam.

Effect of Different Fertilizer Types on Grain Yield and Greenhouse Gas Emissions from Paddy Field

Sheng Zhou,Xiangfu Song,Huifeng Sun,Zishi Fu,Guifa Chen,Qi Pan 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6