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Does Risk-taking Promote New Product Development Performance? An Environmental Dynamism Perspective
Yunfeng Peng,Jiao Xue,Saixing Zeng,Xiaohua Meng 한국증권학회 2018 Asia-Pacific Journal of Financial Studies Vol.47 No.3
Using an “entrepreneurial orientation–performance” framework and environmental contingency theory, this study proposes and empirically explores a theoretical framework for understanding the impacts of risk-taking and environmental dynamism on new product development (NPD) performance in emerging markets. We deepen the analysis of environmental dynamism into customer, competitor, supplier, institutional environment, and economic environment. The results demonstrate that risk-taking and environmental dynamism contribute both individually and interactively to the performance of NPD. Further, of all the environmental units, environmental dynamism from suppliers and regulatory groups has a significant, direct and positive moderating effect on the performance of NPD.
Chenchun Shi,Zhenzhong Wang,Yunfeng Peng 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.2
There have been many researches concerning the motion errors of hydrostatic guideways because they directly affect the accuracy of machined parts. Actually, each paired guide rail has its own profile feature, and the position error also cannot be zero, so the relative difference between guide rails should not be neglected. In this paper, a typical closed hydrostatic guideway with four pads is taken as the sample, and the quasi-static analysis model is directly developed by incorporating the concept of pose, which is then employed to study the effect of relative difference on motion accuracy in the field of hydrostatic guideways. The numerical results demonstrate that, the greater the amplitude deviation, the larger the motion errors, while the influence of the wavelength deviation on motion accuracy exhibits regularity only within some intervals, the phase deviation mainly affects the angular but not the linear motion error, the influence from the parallelism error is not significant. Moreover, it is figured out that the fluctuation of the difference between the average film thicknesses of two adjacent pads does result in the variation of the motion errors, the greater the fluctuation, the larger the motion errors. The revealed mechanisms are expected to be valuable for designers.
Interference Cancellation Scheme for Three-hop Cooperative Relay Networks
( Yinghua Zhang ),( Lei Wang ),( Jian Liu ),( Yunfeng Peng ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.9
In this paper, we focus on interference cancellation for three-hop cognitive radio networks (CRNs) over Rayleigh fading channels. In CRNs, secondary users (SUs) are allowed to opportunistically utilize the licensed spectrum during the idle time of primary users (PUs) to achieve spectrum sharing. However, the SUs maybe power constrained to avoid interference and cover a very short transmission range. We here propose an interference cancellation scheme (ICS) for three-hop CRNs to prolong the transmission range of SUs and improve their transmission efficiency. In the proposed scheme, a flexible transmission protocol is adopted to cancel the interference at both secondary relays and destinations at the same time. And a closed-form expression for the secondary outage probability over Rayleigh fading channels is derived to measure the system performance. Simulation results show that the proposed scheme can significantly reduce the secondary outage probability and increase the secondary diversity in comparison with the traditional cases.
Modeling and experimental studies of ammonia absorption in a spray tower
Shichao Ye,Jie Zhu,Zhenhua Liu,Jie Bai,Yunfeng Yang,Qin Peng 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.1
We did an experimental study on ammonia absorption in a spray tower. The kinetic characteristics of droplets were investigated by considering the forces acting on a droplet. The gas-phase mass transfer coefficient was deduced with the Colburn analogy method. A simplified model for predicting NH3 capture with a spray tower has been presented based on mass transfer and ionic equilibrium, which was successfully validated against experimental data. The influences and the sensitivity analysis of main operating parameters on the absorption efficiency were analyzed. As the most sensitive parameter, the mean droplet diameter was obtained by fitting experimental data with an empirical correlation. The distributions of two typical process parameters along the absorber were also simulated. Decreasing the pH value of absorbent is an effective but restrictive way to strengthen the mass transfer rate on account of insufficient liquid-side resistance.