Atlantis Press Journal style Editor’s Introduction for Volume 5, Issue 1 This issue contains six papers which can be divided into five topics: accident calamity, financial risk, risk analysis, social security, and natural hazard assessment. The last contribution is written in Chinese with English abstract. In paper “BP's Reputation Repair Strategies during the Gulf Oil Spill”, Swain and Jordan believe that analysis of 1,161 BP tweets during the crisis response reflected unexpected reputation repair strategies and responsibility attribution. Situational Crisis Communication Theory suggests that after an accident, PR messages typically reflect low responsibility attribution. Although the official investigation initially did not suggest a preventable crisis, 90% of BP’s tweets reflected high responsibility. There are two papers on financial risk. The first paper “Banking Balance Sheet Channel of Systemic Risk” by Gan explores the role of the banking balance sheet as the source and transmitter of systemic risk. This paper discusses the key balance sheet channels of systemic risk. The second paper "Non-Diversifiable Risk In Investment Portfolios an Aid to Investment Decision Making", by Anyika, puts forward Modeling Non - Diversifiable risk in investment portfolios together with redefinition of estimators of diversifiable risk and portfolio expected returns to reflect normal market conditions. He uses GARCH models to make forecasts of given time series, from which future predictions of Non- Diversifiable risk, Diversifiable risk and portfolio expected returns are made. In paper “Quantum-behaved Particle Swarm Optimization with Nelder-Mead Simplex Search Method”, Yao proposes a novel hybrid algorithm for risk analysis, which based on quantum-behaved particle swarm optimization algorithm and Nelder-Mead simplex search method for continuous optimization problems. It seems that the proposed algorithm is more effective and efficient at locating optimal solutions for continues optimization. The paper “Research on Society Risk Evolution Mechanism and Countermeasures in Severe Emergency Infectious Disease— In The Case of H7N9 Avian Influenza”, by Xu, Cai and Wang, analyzes and study the evolution and control of society risks caused by severe emergency infectious disease. Firstly, the evolution chain of society risks caused by severe emergency infectious disease is constructed to analyze the evolution rule of society risks and identify the essential factors in countermeasures. Then, the system dynamics model is established and employed to simulate the effects of society risk control with various countermeasures. Finally, based on the simulation results, a conclusion is drawn: improving medical treatment capacity, strengthening quarantine level under epidemic situation and enhancing the effectiveness of dealing with public opinions are effective in controlling society risks. The paper in natural hazard assessment is written in Chinese, with title “Research of City Rainstorm Waterlogging Scene Simulation -- in Daoli District of Harbin City as an Example”, submitted by Chen, Zhang et al, where authors use a one- dimensional and two-dimensional unsteady flow as the basic equation, with irregular grid as the basic frame, builds urban rainstorm waterlogging deposition numerical simulation model, combining with the information diffusion theory calculation rainstorm probabilities in the study area. On this basis, this paper sets the study area rainstorm waterlogging situation, realizes the different waterlogging scene simulation and visualization. Many thanks to the referees for their strong support and kind help. And also very much thank to the authors for all their submissions. Editor-in-Chief: Prof. Chongfu Huang Email: hchongfu@gmail.com Publication Chair of SRA-China: Prof. Mu Zhang Email: rim_007@163.com Director of Editorial Department: Prof. Junxiang Zhang Email: jracr_srachina@126.com Journal of Risk Analysis and Crisis Response, Vol. 5, No. 1 (April 2015), 1 Published by Atlantis Press Copyright: the authors 1 http://star.co.ke/node/41796 http://star.co.ke/node/41796 mailto:hchongfu@gmail.com mailto:rim_007@163.com mailto:jracr.srachina@126.com