Analysis of Stock Splits Based on Risk Theory: Empirical Evidence from the Chinese Stock Markets

The paper first analyzes price change due to stock splits in Chinese stock markets,which shows stock prices typically go up for stock splits.Then theoretical analyses based on risk theory are presented to explain the reason,where the method comes from a new perspective and obtained theoretical conclusions show that stock splits typically make stock price go up if risk-compensation function is convex,and go down if risk-compensation function is concave.Stock prices typically go up for stock splits because risk-compensation functions are mainly convex.The obtained conclusions are consistent with the known results in the last three decades.

Construction of Public Security Risk Governance System under the View of Risk Society Theory

With the development of economy,China has to fight against the increasing public security risk. The theory of risk society points out that the traditional system of hierarchical management should be transformed into the governance system led by government and participated in by multiple parties to avoid and reduce risk in modern society. In order to achieve modernization of the national governance system and capacity,we have to deal with these two important subjects,that is,what can we learn from the Western risk society theory and how to establish a scientific and efficient public security risk management system based on the characteristics of modern public security risk.

Game Theory Based Sensor Management in Reducing Target Threat Level Assessment Risk

Sensor management schemes are calculated to reduce target threat level assessment risk in this paper.Hidden Markov model and risk theory are combined to build the target threat level model firstly.Then the target threat level estimation risk is defined.And the sensor management schemes are optimized with the smallest target threat level assessment risk.What’s more,the game theory is applied to calculate the optimal sensor management scheme.Some simulations are conducted to prove that the proposed sensor management method is effective.

Identification of Critical Lines in Power System Based on Optimal Load Shedding

Based on risk theory, considering the probability of an accident and the severity of the sequence, combining N-1 and N-2 security check, this paper puts forward a new risk index, which uses the amount of optimal load shedding as the severity of an accident consequence to identify the critical lines in power system. Taking IEEE24-RTS as an example, the simulation results verify the correctness and effectiveness of the proposed index.

An improved portfolio optimization model for oil and gas investment selection

For oil company decision-makers,the principal concern is how to allocate their limited resources into the most valuable opportunities.Recently a new management philosophy,＂Beyond NPV＂,has received more and more international attention.Economists and senior executives are seeking effective alternative analysis approaches for traditional technical and economic evaluation methods.The improved portfolio optimization model presented in this article represents an applicable technique beyond NPV for doing capital budgeting.In this proposed model,not only can oil company executives achieve trade-offs between returns and risks to their risk tolerance,but they can also employ an ＂operational premium＂ to distinguish their ability to improve the performance of the underlying projects.A simulation study based on 19 overseas upstream assets owned by a large oil company in China is conducted to compare optimized utility with non-optimized utility.The simulation results show that the petroleum optimization model including ＂operational premium＂ is more in line with the rational investors＇ demand.

Modeling on monitoring the growth and rupture assessment of saccular aneurysms

The unpredictable rupture of saccular aneurysms especially of the intracerebral aneurysm is a knotty problem that always results in high mortality. Traditional diagnosis of medical images, which gives the aneurysm size and compares with a speculated critical size from clinical statistics, was demonstrated inadequate to forecasting rupture. Here, we propose a new detecting strategy that uses a dielectric elastomer （DE） capacitance sensor to monitor the growth of saccular aneurysms and deliver both the wall stress and geometric parameters, Based on the elastic growth theory together with the finite deformation analyses, the correlation between the real-time output capacitance of the DE sensor and the wall stress and/or geometry of an aneurysm is derived. Compared to clinic statistics and biomechanics simulations, the wall stress and geometric size may be used as combined indicators to assess the rupture risk of a saccular aneurysm, Numerical results show that an output relative capacitance of 30 indicates a high risk of rupture, Finally, the sensitivity and resolution of the DE sensor are proved adequately high for monitoring the growth state and evaluating the rupture risk of a saccular aneurysm.

Theory of mind impairments in individuals at ultra-high risk for psychosis

Objective To determine deficits in theory of mind in individuals at ultra-high risk for psychosis(UHR),and to explore the relations between theory of mind and symptom severity.Methods Twenty seven ultra-high-risk patients in clinics of the Peking University Sixth