Flood risk control of dams and dykes in middle reach of Huaihe River

Three stochastic mathematical models for calculation of the reservoir flood regulation process, river course flood release, and flood risk rate under flood control were established based on the theory of stochastic differential equations and features of flood control systems in the middle reach of the Huaihe River from Xixian to the Bengbu floodgate, comprehensively considering uncertain factors of hydrology, hydraulics, and engineering control. They were used to calculate the flood risk rate with flood regulation of five key reservoirs, including the Meishan, Xianghongdian, Nianyushan, Mozitan, and Foziling reservoirs in the middle reach of the Huaihe River under different flood frequencies, the flood risk rate with river course flood release under design and check floods for the trunk of the Huaihe River in conjunction with relevant flood storage areas, and the flood risk rate with operation of the Linhuaigang Project under design and check floods. The calculated results show that （l） the five reservoirs can withstand design floods, but the Xianghongdian and Foziling reservoirs will suffer overtopping accidents under check floods; （2） considering the service of flood storage areas under the design flood conditions of the Huaihe River, the mean flood risk rate with flood regulation of dykes and dams from Xixian to the Bengbu floodgate is about 0.2, and the trunk of the Huaihe River can generally withstand design floods; and （3） under a check flood with the flood return period of 1 000 years, the risk rate of overtopping accidents of the Linhuaigang Project is not larger than 0.15, indicating that it has a high flood regulation capacity. Through regulation and application of the flood control system of the Linhuigang Project, the Huaihe River Basin can withstand large floods, and the safety of the protected area can be ensured.

Evaluating rockfalls at a historical settlement in the Ihlara Valley(Cappadocia, Turkey) using kinematic, numerical, 2D trajectory, and risk rating methods

Rockfalls are one of the most dangerous natural events in hilly terrains, and they substantially threaten residential areas and transport corridors in these environments. This study is aimed to analyze the risk of rockfall from a slope to nearby houses in a historical settlement with past rockfall histories. It contains numerous applications to study rockfall danger from different points of view(e.g., kinematics,numerical stability analysis, risk assessment, 2D trajectory). The rockfall kinematics revealed the statistics for different structurally controlled failure modes among the surveyed slope discontinuities,especially wedge type and block toppling were the most significant ones. Finite element analysis showed that the slope was stable under the natural condition with a safety factor of 2.19. The rockfall risk rating system calculated a medium risk for the houses downstream. Based on the field measurements, a possible rockfall profile was determined and located as an input in the 2D rockfall trajectory program. The rigid-body impact model runs utilized various shapes and sizes of blocks to simulate the rockfall events realistically. According to the 2D trajectory model results, there was no rockfall danger for the investigated downslope houses. The study showed the importance of using different analysis techniques to solve rockfall risk in protected areas based on scientific and rational approaches.

Development of Jacket Platform Tsunami Risk Rating System in Waters Offshore North Borneo

This work details the simulation of tsunami waves generated by seaquakes in the Manila Trench and their effect on fixed oil and gas jacket platforms in waters offshore North Borneo. For this study, a four-leg living quarter jacket platform located in a water depth of 63 m is modelled in SACS v5.3. Malaysia has traditionally been perceived to be safe from the hazards of earthquakes and tsunamis. Local design practices tend to neglect tsunami waves and include no such provisions. In 2004, a 9.3Mw seaquake occurred off the northwest coast of Aceh, which generated tsunami waves that caused destruction in Malaysia totalling US$ 25 million and 68 deaths. This event prompted an awareness of the need to study the reliability of fixed offshore platforms scattered throughout Malaysian waters. In this paper, we present a review of research on the seismicity of the Manila Trench, which is perceived to be high risk for Southeast Asia. From the tsunami numerical model TUNA-M2, we extract computer-simulated tsunami waves at prescribed grid points in the vicinity of the platforms in the region. Using wave heights as input, we simulate the tsunami using SACS v5.3 structural analysis software of offshore platforms, which is widely accepted by the industry. We employ the nonlinear solitary wave theory in our tsunami loading calculations for the platforms, and formulate a platform-specific risk quantification system. We then perform an intensive structural sensitivity analysis and derive a corresponding platform-specific risk rating model.

Study on models for control of interest rate risks

Analyses different interest rate risks, presents a new model for assessment of interest rates and thereby establishes the framework for control of interest

Research on the Pricing of Convertible bonds in China Migration risk based on credit rating

At present,further research and exploration on credit risks are being carried out in the global field,and increasingly profound modem credit risks are exposed to the bond market.This requires that we cannot ignore the impact of credit rating migration risk on bond pricing,so as to adapt to the sustainable and healthy development of the bond market under the new normal of China's economy.The innovation point of this paper is to try to analyze the pricing of Convertible bonds in China from the perspective of credit rating migration risk.Tsiveriotis and Femandes(1998)model is selected,and the credit risk in the model is assumed to be caused by the credit rating migration risk,and the credit spread is used to measure the credit rating migration risk.The research conclusion of this paper is as follows:First,it is valid to consider the risk of credit rating migration in the TF(1998)model.The market price of convertible bonds is on average 1.22% higher 1han the theoretical value of the model.In general,the theoretical value obtained from the model has little deviation from the market price,and has a good fitting degree.Second,from the Angle of credit rating,the selection of 32 samples of convertible bonds only empirical research shows that the credit rating of AA-convertible bonds average deviation rate is negative,suggest that the credit rating of AA-the phenomenon of convertible bonds value is underestimated,and AAA credit rating to AA,AA+,the average deviation rate of convertible bonds is positive,that credit rating AA(containing AA)more convertible bond value is overrated phenomenon,and the higher the credit rating of the average deviation rate of convertible bond,the greater the overvalued levels.It has certain guiding significance for participants in the convertible bond market.

A quantitative model for danger degree evaluation of staged operation of earth dam reservoir in flood season and its application

Based on the natural disaster risk evaluation mode, a quantitative danger degree evaluation model was developed to evaluate the danger degree of earth dam reservoir staged operation in the flood season. A formula for the overtopping risk rate of the earth dam reservoir staged operation was established, with consideration of the joint effect of flood and wind waves in the flood sub-seasons with the Monte Carlo method, and the integrated overtopping risk rate for the whole flood season was obtained via the total probability approach. A composite normalized function was used to transform the dam overtopping risk rate into the danger degree, on a scale of 0-1. Danger degree gradating criteria were divided by four significant characteristic values of the dam overtopping rate, and corresponding guidelines for danger evaluation are explained in detail in this paper. Examples indicated that the dam overtopping danger degree of the Chengbihe Reservoir in China was 0.33-0.57, within the range of moderate danger level, and the flood-limiting water level （FLWL） can be adjusted to 185.00 m for the early and main flood seasons, and 185.00-187.50 m for the late flood season. The proposed quantitative model offers a theoretical basis for determination of the value of the danger degree of an earth dam reservoir under normal operation as well as the optimal scheduling scheme for the reservoir in each stage of the flood season.

Rockfall hazard assessment in a natural and historical site: The case of ancient Kilistra settlement(Konya), Turkey

The ancient Kilistra settlement is a natural,historical and cultural heritage site in Central Anatolia(Turkey), which makes it an attractive destination for tourists. However, the settlement located on a hill with steep hillsides has suffered from rockfall events,causing the destruction of some historical buildings.The rockfall risk in the region continues to create a serious danger today for land users and visitors during uncontrolled tourist visits. This paper offers an assessment of rockfall hazard for the ancient Kilistra settlement based on experimental investigation and numerical analyses. For the study, comprehensive field studies were carried out, including the identification of slope profiles, scanline surveys on discontinuities and stability analysis of the slopes. The location and size of the fallen, detached and hanging blocks were also identified. Geomechanical properties of the geological units were determined, and also the rockfall risk rating method was applied for the evaluation of the rockfall hazard risk. Runout distance, bounce height, kinetic energy as well as the velocity of the detached and hanging blocks were determined by using twodimensional rockfall analyses. Based on the results from the rockfall analyses, possible rockfall-based danger zones have been defined for the ancient Kilistra settlement and its close vicinity. The results of this study point at an immediate necessity for the installation of support systems. Findings of the study also offer preliminary data for the description of risk administration strategies and also provide scientific contribution to the study of the hazard and risk resulting from rockfall phenomena.

Heart Rate Distribution and Cause-specific Death in General Population of South China

Objectives To analyses heart rate （HR） distribution of healthy adults in the south China community and evaluate relative risk of HR to total cause of death and cardiac cerebral vascular death. Methods Analytical data come from the baseline survey and follow-up visits in the PRC-USA Collaborative Study of Cardiovascular Epidemiology in urban and rural samples of Guangzhou. The baseline survey was initiated in 1983 and 1984, and rescanned in 1987 and 1988. Since 1991 Follow-up visits for endpoint events were carried once every two years. Average follow-up year was 16.2 from baseline to 2000. People excluded from cardiac cerebral vascular disease, diabetes and other various chronic diseases were regarded as ＂healthy adults＂. Heart rates of these subjects were measured on resting electrocardiogram. Endpoint evens include： total cause of death, first attack of coronary disease and cerebral vascular events. SAS software was used for analysis. Cox Proportional Hazards model was used to evaluate the impact of HR on total death and cardiac cerebral vascular disease. Results A total of 4570 men and women aged 35-55 years from urban and rural Guangzhou were investigated. 3493 healthy subjects were enrolled in the analysis, including 1694 men and 1799 women. Mean oftheHRis （67.9 ±10.6） beats/min （bpm） in the whole population, （66.3±10.7）bpm in men and （69.3± 10.4） in women. The 52 percentile of the HR was 51 in men and 54 in women. The 952 percentile of the HR was 85 in men and 88 in women. Single correlation analysis showed there was negative relationship between age and HR, but it was only statistical significant in female. Analysis with Cox Proportional Hazards model show that HR 〈 50 bpm tops the risk of total causes of death （1.725）and HR 50-59 bpm decreased the risk of total causes of death （0.843）. Relative risk of cardiac cerebral vascular events exceeds 1 when HR 〈 50 and 〉90 bpm （1.486 and 7.008 respectively）. It was less than 1 in other groups but there was no significant difference between each group. Conclusions Traditional normal range of HR in adult should be adjusted. In certain extent lower HR is advantageous to decrease cardiac cerebral vascular events, total causes of death and has better prognosis.

The valuation of multi-counterparties CDS with credit rating migration

In this paper,the pricing of a Credit Default Swap(CDS)contract with multiple counterparties is considered.The pricing model takes into account the credit rating migration risk of the reference.It is a new model established under the reduced form framework,where the intensity rates are assumed to have structural styles.We derive from it a non-linear partial differential equation system where both positive and negative correlations of counterparties and the references are considered via a single factor model.Then,an ADI(Alternating Direction Implicit)difference method is used to solve the partial differential equations by iteration.From the numerical results,the comparison of multi-counterparty CDS contract and the standard one are analyzed respectively.Moreover,the impact of default parameters on value of the contracts are discussed.

Predicting Bank Interests When Monetary Rates Are Close to Zero

Monetary policies, either actual or perceived, cause changes in monetary interest rates. These changes impact the economy through financial institutions, which react to changes in the monetary rates with changes in their administered rates, on both deposits and lendings. The dynamics of administered bank interest rates in response to changes in money market rates is essential to examine the impact of monetary policies on the economy. Chong et al. (2006) proposed an error correction model to study such impact, using data previous to the recent financial crisis. In this paper we examine the validity of the model in the recent time period, characterized by very low monetary rates. The current state of close-to-zero monetary rates is of particular relevance, as it has never been studied before. Our main contribution is a novel, more parsimonious, model and a predictive performance assessment methodology, which allows comparing it with the error correction model.

GOVERNMENT POLICIES AND CORPORATE FINANCING DECISIONS IN CHINA:THEORY AND EVIDENCE

This paper examines the effect of government policies on the financing decisions of firms in China. A real options model is developed to understand how fiscal and monetary policies affect corporate leverage.The model predictions will be tested with a comprehensive panel data set spanning from 2002 to 2011.This work documents robust evidence that show the positive association of both tax and risk-free rate with firm leverage：increase in tax rate and risk free rate by one standard deviation results in the increase in corporate leverages by 0.61 to 1.06 percent and 2.54 to 3.68 percent,respectively.In addition,the productions of the firms are not affected by the tax rate in the short run,and the firms are operating in their optimal market leverage.The implied tax rate and risk free rate are solved by assuming that the firms achieve their optimal leverages.The implied tax rate declines with the size, whereas the opposite goes for implied risk-free rate.

Effects of decline in renal function with age on the outcome of asymptomatic carotid plaque in healthy adults： a 5-year follow-up study

Background It has been long suggested that abnormal clinical factors in the body, such as dyslipidemia and diabetes, can affect the presence of atherosclerosis. However, few studies on the effect of factors within the normal range, such as the loss of renal function with age, on the prevalence of atherosclerosis are few know in healthy individuals. The aim of this study was to investigate risk factors affecting the presence of asymptomatic carotid plaques in a middle-aged and elderly healthy population. Methods In this regard, we prospectively evaluated 245 healthy individuals （98 males and 147 females） at baseline and after 5 years. Changes in the presence of carotid plaque between 2003 and 2008 were categorized into four groups, i.e. subjects without plaque at entry （n=165）： Group 1 （without plaque on two occasions, n=129） and Group 2 （with nascent plaque at follow-up, n=36）; subjects with plaque at entry （n=80）; Group 3 （with plaque regression at follow-up, n=29） and Group 4 （with plaque on two occasions, n=51）. Results Univariate analysis showed that the positive rate of carotid plaques in males was higher than that in females at the baseline, and that a significantly inverse correlation existed between the prevalence rate of plaque and aging. Logistic regression analysis of cross-sectional research showed that independent risk factors for the prevalence of atherosclerosis were male gender, lower estimated glomerular filtration rate （eGFR） and higher low-density lipoprotein cholesterol （LDL-C） at the baseline, and older age and lower eGFR were involved in the presence of carotid plaques at follow-up point. However, logistic regression analysis of the longitudinal data showed that older age, decreased eGFR and increased systolic blood pressure （SBP） independently predicted the presence of carotid plaques after 5 years in subjects without plaque at entry. In addition, in subjects with plaque at entry, age, changes in eGFR and the baseline levels of serum albumin （ALB） and serum total bilirubin （BIL） dependently influenced the outcome of carotid plaque. Conclusion Physiological decline of renal function, together with advancing age, was an independent risk factor which consistently affected the presence of carotid atherosclerosis in two categories of healthy individuals.