Risk Evaluation of Ammonia Leakage based on Modified Probability Calculation Formulas

Due to its flammable,explosive,and corrosive characteristics,fire,and explosion accidents caused by ammonia leakage occur from time to time.In this work,the concentration distribution of the model was calculated according to the existing formula of probabilistic risk assessment.Using the revised formulas,the leakage of the ammonia room was quantitatively analyzed,and different state parameters were analyzed to find out the dangerous leakage points of the ammonia refrigeration system.The results of the calculation are that the existence of obstacles in the space will increase the probability of leakage risk.And the greater the leakage time to the lower flammability limit accounts for the total leakage time,the greater the risk probability.Dangerous leakage in ammonia systems mainly occurs in storage tanks and condensers.The data show that the dynamic mass flow of ammonia leakage decreases with time,and the leakage diameter increases with the increase of leakage pressure.At the same time,the leakage mass increases gradually with the leakage aperture near circular.

Methodology for estimating probability of dynamical system's failure for concrete gravity dam

Methodology for the reliability analysis of hydraulic gravity dam is the key technology in current hydropower construction.Reliability analysis for the dynamical dam safety should be divided into two phases:failure mode identification and the calculation of the failure probability.Both of them are studied based on the mathematical statistics and structure reliability theory considering two kinds of uncertainty characters(earthquake variability and material randomness).Firstly,failure mode identification method is established based on the dynamical limit state system and verified through example of Koyna Dam so that the statistical law of progressive failure process in dam body are revealed; Secondly,for the calculation of the failure probability,mathematical model and formula are established according to the characteristics of gravity dam,which include three levels,that is element failure,path failure and system failure.A case study is presented to show the practical application of theoretical method and results of these methods.

A CALCULATING METHOD OF THE KILL PROBABILITY ATTACK AREA FOR AAM

This paper provides a calculating method which can be used in calculation of the kill probability attack area for every AAM. At first, attack area of AAM and kill probability of every characteristic point are obtained by combining trajectory calculation with kill probability calculation. Then, coordinates of a fire point relative to standard kill probability value in terms of standardization method are found. At last, equivalent kill probability curve equations are formulated by means of curve fitting method.

Research on Credit Default Swaps Pricing Considering Moral Hazard Incentive under Reduce-Form Model

Equilibrium pricing of credit default swaps(CDS)promotes efficient identification of credit risk in the market,which in turn leads to efficient allocation of resources.However,even when CDS have been priced in equilibrium,i.e.,when premiums are equal to anticipated payments,the moral hazard incentives of CDS buyers increase with CDS transactions.Consequentially,it becomes an interesting research direction to study the impact of moral hazard incentives on the trading mechanism or pricing of derivatives(CDS).Most of the existing literature on the impact of moral hazard incentives in CDS pricing on derivatives trading mechanisms takes a macro perspective and focuses on the agreement risk effect.The literature exploring the analysis of the impact of moral hazard on the probability of agreement default from a micro perspective is not yet available.With this in mind,this paper focuses on the mechanisms by which“fraud”,an extreme manifestation of micro-moral hazard incentives,affects the probability of default.This paper introduces for the first time the concept of“claiming fraud”by credit protection buyers,which is different from the macro perspective of moral hazard incentives,and thus defines a specific extreme form of moral hazard incentives.Meanwhile,to address the intrinsic feature of the lack of economic explanatory power of the reduce-form model,this paper introduces a moral hazard incentive factor into the reduce-form model,and proposes a moral hazard state variable as a function of the asset value of the reference entity,which gives the reduce-form model strong economic explanatory power,and the default predictability is reduced by the description of the reduce-form model.In terms of the object of study,this paper considers the issue of moral hazard incentives in the presence of claiming fraud in two reference entities to further explore the impact of moral hazard incentives on default protection at the micro level in terms of cyclic default.Finally,based on the analysis of the results of the numerical simulation experiments,it is proposed that increasing the number of reference assets for CDS buyers will help to reduce the moral hazard incentives of the buyer,and thus the anticipated payments to the buyer,i.e.,we attempt to endogenize the credit risk of an asset by allowing the asset holder to choose the probability of the asset going up or down,which helps to understand the phenomenon of moral hazard incentives in CDS trading.