计及污闪概率的输电线路运行风险评估理论与指标体系

针对目前高电压技术与输电线路运行可靠性研究相分离的现状,建立了考虑污闪影响的输电线路运行风险评估理论。首先基于一定工作电压下绝缘子的污闪概率模型及条件概率原理得出污闪下线路发生某种故障的概率;其次将污闪严重度定义为污闪电压越限严重度函数、污闪频率越限严重度函数和污闪过负荷严重度函数的加权和并得出系统污闪下各输电线路的运行风险值;最后依据输电线路的风险指标值进行排序,并利用模糊C均值分类法(fuzzy C-means,FCM)将输电线路分成三大类,分别对应着3个辅助决策(不计成本爬/扫/涂,针对性爬/扫/涂,可缓爬/扫/涂)。通过WSCC-9电力系统经典模型算例,进行相关计算仿真,结果验证了该理论的正确性和有效性。

Investigation and Risk Assessment of Alien Invasive Plants in Riparian Zone of Dongjiang River

[Objective] The aim was to conduct investigation and risk assessment of the alien invasive plants in riparian zone of Dongjiang River.[Method] The field survey was carried out by the combination methods of sampling plots investigation and route survey,and the whole Dongjiang River was covered.52 sampling points were set in the main streams,and 87 sampling points in tributaries streams,624 quadrats were set in total;multi-index comprehensive evaluation method was adopted for the risk assessment with 6 first-level indexes and 25 second-level indexes.[Result] Through the investigation on the riparian zone of Dongjiang River for 2 years,51 species of alien invasive plants were found,belonging to 17 families and 38 genera.The risk level assessment results of these 51 species showed that 18 species,such as Ageratum conyzoides,belonged to high-level risk with over 60 points;26 species,such as Chenopodium ambrosioides,were between 30 and 60 points which belonged to middle-level risk;7 species,such as Paspalum dilatatum,with less than 30 points belonged to low-level risk.[Conclusion] Basic data on the protection,water environmental management and functional zoning of riparian zone of Dongjiang River were provided.

Risk Assessment of Highways Affected by Debris Flows in Wenchuan Earthquake Area

Since the Wenchuan earthquake in China on May 12th, 2008, highways in earthquake-affected areas have been frequently interrupted by debris flows. We analyzed the hazard effect modes and damage processes along highways and developed three key indexes, scale of debris flows, deposits on highways and river blockage, to describe quantitatively the highway disasters. By combining the empirical methods and the actual terrain conditions, we proposed new methods to determine the value of hazard indexes. In addition, we used the economic value and resistance of highway as vulnerability assessment indexes, then determined the specific subindexes for the subgrade, bridges and culverts, and developed a way for the quantified vulnerability zoning. Moreover, we proposed the assessment and mapping methods for highway risk. The risk is described into 5 grades： extremely low risk, low risk, middle risk, high risk and extremely high risk. We applied these methods in a case study carried out on provincial highway S3o3 from Yingxiu Town to Wolong Town, in Wenchuan County. Analysis of debris flow risk for the whole highway, showed that the total length of highway in extremely low risk area was 28.26 km, 4.83 km in low risk area, 8.0 km in middle risk area, 3.65 km in high risk area, and 3.06 km in extremely high risk area. The assessment results are consistent with the field survey data which reflected the disaster situation. This risk method can be used objectively to evaluate the debris-flow risk along highways, and is useful for highway reconstruction in mountainous areas suffering from active debris flows.

Risk Assessment of Unmanned Aerial Vehicle Flight Based on Kmeans Clustering Algorithm

To quantify unmanned aerial vehicle(UAV)flight risks in low-altitude airspace,we analyze the factors of UAV flight risks from three aspects:flight conflict,flight environment,and traffic characteristics.The aerial risk index and ground risk index of the UAV are constructed,the index screening model and the UAV flight risk assessment model are established,and a UAV flight risk assessment model based on K-means clustering has been proposed.Meanwhile,numerical simulations show the proposed method can not only evaluate the UAV flight risks effectively,but also provide technical support for UAV risk management and control.

Nonalcoholic fatty liver disease is a novel predictor of cardiovascular disease

AIM:To clarify whether nonalcoholic fatty liver disease(NAFLD)increases the risk of cardiovascular disease.METHODS:We carried out a prospective observational study with a total of 1637 apparently healthy Japanese men and women who were recruited from a health check-up program.NAFLD was diagnosed by abdominal ultrasonography.The metabolic syndrome(MS)was defined according to the modified National Cholesterol Education Program(NCEP)ATP Ⅲ criteria.Five years after the baseline evaluations,the incidence of cardiovascular disease was assessed by a self-administered questionnaire.RESULTS:Among 1221 participants available for outcome analyses,the incidence of cardiovascular disease was higher in 231 subjects with NAFLD at baseline(5 coronary heart disease,6 ischemic stroke,and 1 cerebral hemorrhage)than 990 subjects without NAFLD(3 coronary heart disease,6 ischemic stroke,and 1 cerebral hemorrhage).Multivariate analyses indicated that NAFLD was a predictor of cardiovascular disease independent of conventional risk factors(odds ratio 4.12,95% CI,1.58 to 10.75,P = 0.004).MS was alsoindependently associated with cardiovascular events.But simultaneous inclusion of NAFLD and MS in a multivariate model revealed that NAFLD but not MS retained a statistically significant correlation with cardiovascular disease.CONCLUSION:Although both of them were predictors of cardiovascular disease,NAFLD but not MS retained a statistically significant correlation with cardiovascular disease in a multivariate model.NAFLD is a strong predictor of cardiovascular disease and may play a central role in the cardiovascular risk of MS.

Effects of High-temperature Damage on Rice Growth and Its Countermeasures

This study introduced the effects of high-temperature damage on rice and reviewed the damage mechanism, heat damage index and risk assessment, forewarning and monitoring. On the basis of extensive studies, this paper put forward the viewpoints of ascertaining the fundamental mechanism of high temperature damage to rice at the molecular level, establishing a comprehensive heat damage index taking variety, growth stage and other meteorological factors into consideration, selecting appropriate sowing time, choosing heat-resistant varieties and improving the prevention system. All of these are aimed at providing a solid foundation for coping avoiding the harms from heat damage and improving the coping method.

Risk Assessment of Secondary Geological Disasters Induced by the Yushu Earthquake

The Yushu Ms 7.1 earthquake occurred on April 14,2010 in Qinghai Province,China.It induced a mass of secondary geological disasters,such as collapses,landslides,and debris flows.Risk assessment maps are important for geological disaster prevention and mitigation,and also can serve as a guide for post-earthquake reconstruction.Firstly,a hazard assessment index system of secondary geological disasters in the earthquake region was built in this paper,which was based on detailed analysis of environmental and triggering factors closely related to geological disasters in the study area.GIS technology was utilized to extract and analyze the assessment index.Hazard assessment maps of secondary geological disasters were obtained by spatial modeling and overlaying analysis.Secondly,an analysis of the vulnerability of hazard bearing bodies in the area was conducted,important information,such as, population density,percentage of arable land, industrial and agricultural outputs per unit area were regarded as assessment indices to evaluate socioeconomic vulnerability.Thirdly,the risk level of secondary geological disasters of the area was obtained by the formula:Risk=Hazard×Vulnerability. Risk assessment maps were categorized into four levels,including"low","moderate","high"and"very high".These results show that some urban areas are at very high risk,including Jiegu,Chengwen,Xiaxiula and Sahuteng towns.This research can provide some references and suggestions to improve decisionmaking support for emergency relief and post- earthquake reconstruction in the study area.

Development of emergency water quality standard for Cr^(6+) and Hg^(2+) in Liao River basin

The acute toxicity data of Cr＋ and Hg2＋ to the aquatic organisms in Liao River basin was collected and screened. Calculated results of criteria values using popular species sensitivity distribution （SSD） methods were evaluated through data analysis. The comprehensive methodology of emergency water quality standards （EWQSs） was established on the basis of the SSD method of Australia and New Zealand according to the evalu- ation results. The affected fractions of the aquatic organisms were set to be 5 %, 15 %, 30 % and 50 %, corre- sponding to the risk grades of Ⅰ,Ⅱ,Ⅲ and IV, and four-grade EWQSs, respectively. The EWQSs for Cr6＋ and Hg2. in the Liao River were derived and the corresponding risk indicators were also proposed. The results showed that the four-grade EWQSs for Cr6＋ were 2.85 μg/L, 21.0 μg/L, 161 μg/L and 797 μ/L, respec- tively, and the risk indicators were daphnia （grade Ⅱ ）, shrimp （grade Ⅲ）, and the bighead fish or tadpole （grade IV）. The four-grade EWQSs for Hg2＋ were 0.59 μg/L, 2.32 μg/L, 6.25 μg/L and 15.6 μg/L, respective- ly, and the risk indicators were crucian carp or daphnia （grade Ⅱ）, shrimp （grade Ⅲ）, and worm or crab （grade IV）. The results provided valuable information for the risk analysis of sudden ambient water environmen- tal pollution accident.

Risk-analysis-based research and application of land use planning

The establishments which produce,store and use kinds of inflammable,explosive or toxic materials may induce accident,such as fire,explosion or poisonous gas dispersion,etc. Therefore,there is a need to locate these establishments appropriately and conduct land use planning in the vicinity of these establishments based on risk analysis. Consulting advanced experience which obtained from land-use planning in European countries,this paper studied on locating hazardous establishment based on risk index,land-use planning based on consequence-probability,and land-use planning based on individual risk. Frameworks and procedures of the three approaches above were determined and applied to a proposed LNG station. The results show three methods are feasible when major projects' location and their surrounding buildings or establishments' layout are considered.

The Impact of Foreign Bank Strategies on the Behavior and Performance of Czech and Slovak Banks in the Financial Crisis

In this paper, the authors analyze the impact of the specific ownership structure of the banking sector in Czech and Slovakia on the performance and applied strategies of particular banks during times of crisis. Did the multinational banks pursue a coherent regional strategy to cope with the risks resulting from the crisis, or did they focus on finding local solutions？ The aim of this paper is to find answers to these questions. A case study is going to be used as a basic research method. Two members （Slovak and Czech） of four multinational banking groups are examined in the crisis year 2009, whereby both a qualitative analysis of the annual reports regarding strategic business or risk management decisions and a comparative quantitative analysis of selected financial data and risk indicators are employed. The authors have found that Czech and Slovak banks generally tried to follow the main strategic directions given by their parent banks during the financial crisis. However, particular financial results and risk profiles of respective subsidiaries of multinational banks still differ because of market factors specific to the different countries in which the subsidiaries are located.

Development and Application of Oil-Spill Risk Assessment Model for Offshore Pipeline

To the potential oil-spill risk caused by offshore pipeline more attention has been paid after the Dalian oil spill incident from oil-pipeline explosion. Since then an issue about how to prevent and control the sudden oil-spill from the offshore pipeline has been raised. In this paper, we proposed an optimized model to analyze the main causes(probability) of spill and the consequence with the fuzzy comprehensive assessment model. Considering the complicated assessment process for oil-spill, the assessment factor system involving the spill probability and consequence was established based on the operative manual and statistic leakage/damage data of offshore pipeline in order to estimate the integrated spill risk score automatically. The evaluated factors of spill probability could be grouped into five aspects: corrosion, fatigue, national damage, third party, and operational fault; the consequence evaluated factors of spill included hazard of oil and impact-controlling capability. With some modifications based on experts' opinions, each of the evaluated factors in our work was developed with a relative weight and evaluation criterion. A test example for an offshore pipeline in the Bohai waters was described to show how the model can be used for an actual case in more detail. By using the oil-spill risk assessment model, it is easy to determine the risk level associated with the ongoing activity and management level and hence to take the risk mitigation action immediately.

Risk reduction in Sechahun iron ore deposit by geological boundary modification using multiple indicator Kriging

Uncertainty on the geological contacts and the block volumes of the models along boundaries is often a major part of the global uncertainty of reserve estimation.This work introduces a geostatistical technique that has been developed and tested in an iron ore deposit at Bafq mining district,in central Iran,and that,based on a probability criterion,helps to objectively model the geometry of this iron ore deposit.The main problem in reserve estimation of this ore body is its geometrical modeling and uncertainty in geological boundaries.This work deals with the geostatistical method of multiple indicator kriging,which is used to determine the real boundaries of ore body in different categories.This approach has potential to improve project performance and decrease operational risk.For this purpose,the ore body is separated into two categories including rich iron zone(w(Fe)>45%)and poor iron zone(20%<w(Fe)<45%).It significantly benefits to decrease the risk of reserve evaluation in the deposit.This case study also highlights the value of multiple indicator kriging as a tool for estimates the position of grade boundaries within the deposit.Comparison of the resultant probability maps with the real ore/waste contacts on the extracted levels shows that the first indicator model could separate the whole ore body(poor plus rich)from the waste zone by probability of more than 0.35,which concludes the total reserve of 53 million tons.The second indicator model applied to separate the rich and poor domains and the results show that the blocks with the estimated probability of equal to or more than 0.4 lay within the rich ore zone consisting of 15.8 million tons reserve.

Missing Dollars： Significant Statistical Omissions of Global Monetary Aggregates

The choice of liquidity indicators is a key issue in global liquidity management. Money supply statistics such as M2 are no longer able to reflect the true scale of global liquidity due to the effect of financial globalization. External bank liabilities, as an important indicator to measure global liquidity conditions, are omitted by many countries in their broad money statistics. Given that financial institutions＇ external liabilities serve as a major source of fiscal shock as well as an important cause for the accumulation of monetary risk, it is imperative to include these external liabilities into the global liquidity indicator system.

Identification and prevention research at the present stage of our corporate financial risk

Corporate finance activities recur throughout the entire process of production and operation. The financial risk is a signal, which can fully reflect the company＇ s consolidated operating conditions. Therefore it requires business owners to conduct regular financial analysis, establish risk awareness, establish effective risk precautionary handling mechanism, strengthen financial risk control, prevent financial crises, establish early warning indicator system, and make proper financial risk decisions. Firstly, a correct understanding of the financial risk from the start, its meaning, characteristics, and so do the reasons for the formation of the exposition clear what financial risks ; Secondly, the financial risk of the formation of a variety of reasons were analyzed.

Healthcare Risk Management and Patient Safety in Turkish Hospital

Patient safety is an important component of risk management in hospitals. The aim of the study is to measure physician and nurse awareness about four selected patient safety indicators by authors and events reported about these relevant indicators in the hospital. The study uses standardized four patientsafety indicators like ＂needle sticks, cut wounds, dressing allergy, infections indicators＂. Cross section study was conducted through three month period in 2011-2012 based on voluntary response to the questionnaire that intend to measure knowledge about four health indicators. Studypopulations consisted of accessible sample of 146 different specialty physicians and 108 nurses present on duty during survey period. The association between the patient safety indicators and events reported about indicators in questionswere analyzed. Meanpatient safety knowledge questionnaire scores of health staff （nurse and physician） for needle sticks, cut wounds, dressing allergy, infections indicators were 47.13（11.8）, 39.04（14.5）, 38.02（10.5）, 39.72（9.7）, respectively. Significant statistical differences were also found between the frequency of events reported according to department and patient safety indicators （F = 8.34; p 〈 0.05） Measuring patient safety culture via safety indicators is essential in improving patient safety. This matter is perfectly influence the financial management of the hospital.

Dynamic Statistical Models for Corporate Failure Prediction in Italy

Different models have been proposed in corporate finance literature for predicting the risk of firm＇s bankruptcy and insolvency. In spite of the large amount of empirical findings, significant issues are still unsolved. In this paper, the authors developed dynamic statistical models for bankruptcy prediction of Italian firms in the industrial sector by using financial indicators. The model specification has been obtained via different variable selection techniques, and the predictive accuracy of the proposed default risk models has been evaluated at various horizons by means of different accuracy measures. The reached results give evidence that dynamic models have a better performance in any of the considered scenarios.

Application of the catastrophe progression method in predicting coal and gas outburst

Based on catastrophe theory,we used the catastrophe progression method to predict the risk of coal and gas outbursts in coal mines.According to the major factors affecting coal and gas outbursts,we built a comprehensive evaluation index system and a coal and gas outburst prediction model.In addition,we performed a standard transformation for each index system;based on the degree the various indices affect the risk of an outburst,to make the data dimensionless.Based on the outburst data from eight mines,we determined catastrophe progression values and verified these values.The results show that:1) converting multi-dimensional problems into one-dimensional problems using this catastrophe progression method can simplify the steps of predicting coal and gas outbursts;2) when pre-determined catastrophe progression values are used to predict coal and gas outbursts,the predicting accuracy rate can be as high as 87.5%;3) the various coal mines have different factors inducing outbursts with varying importance of these factors and 4) the catastrophe progression values,calculated based on these factors,can be used effectively to predict the risk of outbursts in coal mines.

Intensity measures for seismic liquefaction hazard evaluation of sloping site

This work investigates the correlation between a large number of widely used ground motion intensity measures(IMs) and the corresponding liquefaction potential of a soil deposit during earthquake loading. In order to accomplish this purpose the seismic responses of 32 sloping liquefiable site models consisting of layered cohesionless soil were subjected to 139 earthquake ground motions. Two sets of ground motions, consisting of 80 ordinary records and 59 pulse-like near-fault records are used in the dynamic analyses. The liquefaction potential of the site is expressed in terms of the the mean pore pressure ratio, the maximum ground settlement, the maximum ground horizontal displacement and the maximum ground horizontal acceleration. For each individual accelerogram, the values of the aforementioned liquefaction potential measures are determined. Then, the correlation between the liquefaction potential measures and the IMs is evaluated. The results reveal that the velocity spectrum intensity(VSI) shows the strongest correlation with the liquefaction potential of sloping site. VSI is also proven to be a sufficient intensity measure with respect to earthquake magnitude and source-to-site distance, and has a good predictability, thus making it a prime candidate for the seismic liquefaction hazard evaluation.

Research on Risk Assessment of City Natural Disaster based on Neural Network

Aiming at the selection of fuzzy AHP and fuzzy DH methods in the previous studies, this paper evaluate the qualitative index system using expert questionnaire, the self-learning BP neural network model to construct the index of system, and complete the establishment of model, in order to avoid the serious subjectivity, and using statistical and measurement methods test the reliability index, analyze the validity of the evaluation index system and completeness. Finally, the paper validate the practicability of the model.

Directional Overcurrent Relays Coordination Restoration by Reducing Minimum Fault Current Limiter Impedance

FCL （fault current limiter） is used to solve relays miscoordination problem arises from DG （distributed generation） installation. In most published researches, different optimization methods are developed to obtain optimal relay settings to achieve coordination in case of not installing DG, then depending on the achieved optimal obtained relay settings, FCL impedance is deduced to ensure relays coordination restoration in case of installing DG. Based on original optimal relay settings, obtained FCL impedance is not the minimum one required to achieve relay coordination. The contribution of this paper is the generation of multi sets of original relay settings that increase the possibility of finding FCL impedance of minimum value which is lower than the calculated value based on original optimal relay settings. The proposed method achieves better economic target by reducing FCL impedance. The proposed approach is implemented and tested on IEEE-39 bus test system.