Proactive Risk Handling Compared between the Enterprises in Hebei, China and Flanders, Belgium

Zhan Jun 인하대학교 정석물류통상연구원 2009 인하대학교 정석물류통상연구원 학술대회 Vol.2009 No.10

Despite the current entrepreneurship theory takes risk taking as one of the elementary dimensions of entrepreneurial orientation, a large number of research findings from empirical studies indicate, in real practices of business management and entrepreneruial activities, entrepreneurs and top management always employ risk intelligence and early precautious measures to avoid or mitigate the impact of the risks or uncertainties they will be confronted with. Being proactive shile faced up with risks and uncertainties, the entrepreneurs accept the calculated risks rather than passively take the sufferings of the risks. Thus, proactive risk handling is more pertinent than risk taking for being a dimension of entrepreneurial orientation. In this paper, we briefly explain the definition and constructs of proactive risk handling, and its operationalization. Besides, by taking case study as the research method, we present the empirical findings on the behaviour of proactive risk handling compared between the enterprises in Hebei, Chian and Flander, Belgium. Moreover, the contextual determinants are also exposed to explain the reasons behinds the behaviours.

Relaying Protocols and Delay Analysis for Buffer-aided Wireless Powered Cooperative Communication Networks

( Jun Zhan ),( Xiaohu Tang ),( Qingchun Che ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.8

In this paper, we investigate a buffer-aided wireless powered cooperative communication network (WPCCN), in which the source and relay harvest the energy from a dedicated power beacon via wireless energy transfer, then the source transmits the data to the destination through the relay. Both the source and relay are equipped with an energy buffer to store the harvested energy in the energy transfer stage. In addition, the relay is equipped with a data buffer and can temporarily store the received information. Considering the buffer-aided WPCCN, we propose two buffer-aided relaying protocols, which named as the buffer-aided harvest-then-transmit (HtT) protocol and the buffer-aided joint mode selection and power allocation (JMSPA) protocol, respectively. For the buffer-aided HtT protocol, the time-averaged achievable rate is obtained in closed form. For the buffer-aided JMSPA protocol, the optimal adaptive mode selection scheme and power allocation scheme, which jointly maximize the time-averaged throughput of system, are obtained by employing the Lyapunov optimization theory. Furthermore, we drive the theoretical bounds on the time-averaged achievable rate and time-averaged delay, then present the throughput-delay tradeoff achieved by the joint JMSPA protocol. Simulation results validate the throughput performance gain of the proposed buffer-aided relaying protocols and verify the theoretical analysis.

A Clustering Sleep Scheduling Mechanism Based on Sentinel Nodes Monitor for WSN

Zhan-Yang Xu,Song-Gang Zhao,Zheng-Jun Jing 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.1

This paper proposes a clustering sleep scheduling mechanism based on sentinel nodes monitoring for WSN. The mechanism combines the network clustering strategy with the node dormancy strategy, and improves the method of selecting the candidate cluster heads randomly in Energy-Efficient Unequal Clustering (EEUC) algorithm. The conception of sentinel node is introduced based on EEUC, and the neighbor node set of sentinel node will be dormant when the sentinel node’s data change rate is lower than the setting threshold. Simulation results show that this mechanism can effectively balance the energy consumption of the entire network, and significantly extend the network lifetime.

Relaying Protocols and Delay Analysis for Buffer-aided Wireless Powered Cooperative Communication Networks

Zhan, Jun,Tang, Xiaohu,Chen, Qingchun Korean Society for Internet Information 2018 KSII Transactions on Internet and Information Syst Vol.12 No.8

In this paper, we investigate a buffer-aided wireless powered cooperative communication network (WPCCN), in which the source and relay harvest the energy from a dedicated power beacon via wireless energy transfer, then the source transmits the data to the destination through the relay. Both the source and relay are equipped with an energy buffer to store the harvested energy in the energy transfer stage. In addition, the relay is equipped with a data buffer and can temporarily store the received information. Considering the buffer-aided WPCCN, we propose two buffer-aided relaying protocols, which named as the buffer-aided harvest-then-transmit (HtT) protocol and the buffer-aided joint mode selection and power allocation (JMSPA) protocol, respectively. For the buffer-aided HtT protocol, the time-averaged achievable rate is obtained in closed form. For the buffer-aided JMSPA protocol, the optimal adaptive mode selection scheme and power allocation scheme, which jointly maximize the time-averaged throughput of system, are obtained by employing the Lyapunov optimization theory. Furthermore, we drive the theoretical bounds on the time-averaged achievable rate and time-averaged delay, then present the throughput-delay tradeoff achieved by the joint JMSPA protocol. Simulation results validate the throughput performance gain of the proposed buffer-aided relaying protocols and verify the theoretical analysis.

Probabilistic Prediction of Stability of Ship by Risk Based Approach

Zhan-Jun Long,이승건,이성종,정재훈 한국항해항만학회 2009 한국항해항만학회지 Vol.33 No.4

Prediction of the stability for ships is very complex in reality. In this paper, risk based approach is applied to predict the probability of capsize for a certified ship, which is effected by the forces of sea especially the wave loading. Safety assessment and risk analysis process are also applied for the probabilistic prediction of stability for ships. The probability of ipsencountering different waves at sea is calculated by the existed statistics data and risk based models. Finally, ship capsizing probability is calculated according to single degree of freedom(SDF) rolling differential equation and basin erosion theory of nonlinear dynamics. Calculation results show that the survival probabilities of ship excited by the forces of the seas, especially in the beam seas status, can be predicted by the risk based method.

Study for the Nonlinear Rolling Motion of Ships in Beam Seas

Zhan-Jun Long,Seung-Keon Lee,Jae-Hun Jeong,Sung-Jong Lee 한국항해항만학회 2009 한국항해항만학회 학술대회논문집 Vol.2009 No.추계

Vessels stability problems need to resolve the nonlinear mathematical models of rolling motion. For nonlinear systems subjected to random excitations, there are very few special cases can obtain the exact solutions. In this paper, the specific differential equations of rolling motion for intact ship considering the restoring and damping moment have researched firstly. Then the partial stochastic linearization method is applied to study the response statistics of nonlinear ship rolling motion in beam seas. The ship rolling nonlinear stochastic differential equation is then solved approximately by keeping the equivalent damping coefficient as a parameter and nonlinear response of the ship is determined in the frequency domain by a linear analysis method finally.

Study for the Safety of Ships’ Nonlinear Rolling Motion in Beam Seas

Zhan-Jun Long,Seung-Keon Lee,Jae-Hun Jeong,Sung-Jong Lee 한국항해항만학회 2009 한국항해항만학회지 Vol.33 No.9

Vessels stability problems need to resolve the nonlinear mathematical models of rolling motion. For nonlinear systems subjected to random excitations, there are very few special cases can obtain the exact solutions. In this paper, the specific differential equations of rolling motion for intact ship considering the restoring and damping moment have researched firstly. Then the partial stochastic linearization method is applied to study the response statistics of nonlinear ship rolling motion in beam seas. The ship rolling nonlinear stochastic differential equation is then solved approximately by keeping the equivalent damping coefficient as a parameter and nonlinear response of the ship is determined in the frequency domain by a linear analysis method finally.

LiFePO ₄ microcrystals as an efficient heterogeneous Fenton-like catalyst in degradation of rhodamine 6G

Li, Zhan Jun,Ali, Ghafar,Kim, Hyun Jin,Yoo, Seong Ho,Cho, Sung Oh Springer 2014 NANOSCALE RESEARCH LETTERS Vol.9 No.1

<P>We present a novel heterogeneous Fenton-like catalyst of LiFePO<SUB>4</SUB> (LFP). LFP has been widely used as an electrode material of a lithium ion battery, but we observed that commercial LFP (LFP-C) could act as a good Fenton-like catalyst to decompose rhodamine 6G. The catalytic activity of LFP-C microparticles was much higher than a popular catalyst, magnetite nanoparticles. Furthermore, we found that the catalytic activity of LFP-C could be further increased by increasing the specific surface area. The reaction rate constant of the hydrothermally synthesized LFP microcrystals (LFP-H) is at least 18 times higher than that of magnetite nanoparticles even though the particle size of LFP is far larger than magnetite nanoparticles. The LFP catalysts also exhibited a good recycling behavior and high stability under an oxidizing environment. The effects of the experimental parameters such as the concentration of the catalysts, pH, and the concentration of hydrogen peroxide on the catalytic activity of LFP were also analyzed.</P>

An Investigation into Capsizing Accident and Potential Technology for Vessel Stability Assessment

Long, Zhan-Jun,Jeong, Jae-Hun,Jung, Jin-Woo,Lee, Seung-Keon Korean Institute of Navigation and Port Research 2013 한국항해항만학회지 Vol.37 No.1

In this paper, ship accidents are analyzed briefly and the main objective is to investigate a potential technological approach for risk assessment of vessel stability. Ship nonlinear motion equation and main parameters that induce ship capsizing in beam seas have analyzed, the survival probability of a ferry in random status have estimated and finally find out a risk assessment concept for ship's intact stability estimation by safe basin simulation method. Since a few main parameters are considered in the paper, it is expected to be more accurately for estimating ship survival probability when considering ship rolling initial condition and all other impact parameters in the future research.

Properties and Reaction Mechanisms of Magnesium Phosphate Cement Mixed with Acetic Acid

Li Jun,Ji Yong-sheng,Huang Guo-dong,Xu Zhan-zhan,Yan Gui-hong 대한토목학회 2018 KSCE Journal of Civil Engineering Vol.22 No.1

Objective: This study aims to improve the coagulation time, strength, and construction cost of magnesium phosphate cement. Methods: We analyzed the microstructure changes in the hardened magnesium phosphate cement paste through qualitative analysis, quantitative test, microscopic examination, and research regarding adding different concentrations of acetic acid on magnesium phosphate cement slurry time, effects of flow resistance, and mechanical properties. Results: When a moderate amount of AA was used, the setting time of MAPC mortar was significantly prolonged but was later reduced as the concentration increased. In the early phase, the degree of MAPC mortar hydration increased, whereas compressive strength significantly increased initially and increased slowly in the later phase. The crystal morphology and size of MAPC hydrates changed, and hardened MAPC became more compact in structure. The AA absorbed some ammonia in the MAPC condensation. Conclusion: Acetic acid can effectively regulate coagulation time, induce early hydration reaction rate, and improve the performance of magnesium phosphate cement, which can reduce the construction cost of magnesium phosphate cement.