The evaluation of the electricity market is crucial for fostering market construction and development.An accurate assessment of the electricity market reveals developmental trends,identifies operational issues,and con...The evaluation of the electricity market is crucial for fostering market construction and development.An accurate assessment of the electricity market reveals developmental trends,identifies operational issues,and contributes to stable and healthy market growth.This study investigated the characteristics of electricity markets in different provinces and synthesized a comprehensive set of evaluation indicators to assess market effectiveness.The evaluation framework,comprising nine indicators organized into two tiers,was constructed based on three aspects:market design,market efficiency,and developmental coordination.Furthermore,a novel fuzzy multi-criteria decision-making evaluation model for electricity market performance was developed based on the Fuzzy-BWM and fuzzy COPRAS methodologies.This model aimed to ensure both accuracy and comprehensiveness in market operation assessment.Subsequently,empirical analyses were conducted on four typical provincial-level electricity markets in China.The results indicate that Guangdong’s electricity market performed best because of its effective balance of stakeholder interests and adherence to contractual integrity principles.Zhejiang and Shandong ranked second and third,respectively,whereas Sichuan exhibited the poorest market performance.Sichuan’s electricity market must be improved in terms of market design,such that market players can obtain a fairly competitive environment.The sensitivity analysis of the constructed indicators verified the effectiveness of the evaluation model proposed in this study.Finally,policy recommendations were proposed to facilitate the sustainable development of China’s electricity markets with the objective of transforming them into efficient and secure markets adaptable to the evolution of novel power systems.展开更多
Objective:To explore the application effect of video assessment method in clinical nurses’nursing operation skills.Method:To select 58 nurses who participated in the individual soldier standard in the children’s hos...Objective:To explore the application effect of video assessment method in clinical nurses’nursing operation skills.Method:To select 58 nurses who participated in the individual soldier standard in the children’s hospital in 2019 and 2020 as the research objects,among which the nurses who participated in the individual soldier standard in 2019 were the nurses who participated in the individual soldier standard in 2019 and 2020.A total of 29 people in the first batch were set as the control group,using traditional assessment methods.In 2020,the second batch of 29 nurses who participated in the individual soldier standard reached the experimental group.Using the video assessment method,there was no significant difference in general information between the two groups(P>0.05).After the assessment,the scores,coping with work pressure,and proactiveness of the two groups of research subjects were compared.Results:The experimental group’s nursing operation assessment scores,coping with work pressure,and proactiveness were significantly better than those of the control group,the difference was statistically significant(P<0.05).Conclusion:The application of the video assessment method improves the passing rate of nurses’operational skills examination,enhances nurses’initiative in learning,reduces examination pressure,and can be accurately,timely,and safely applied to clinical nursing work,which is worthy of study and promotion.展开更多
[Objective] The study was to explore the major factors affecting diary cattle brucellosis risk assessment,as well as their strong-to-weak sequence,so as to provide theoretical basis for assessing diary cattle brucello...[Objective] The study was to explore the major factors affecting diary cattle brucellosis risk assessment,as well as their strong-to-weak sequence,so as to provide theoretical basis for assessing diary cattle brucellosis risk level in different regions.[Method] From 4 dimensions of feeding and importing,breeding,housing and polyculture situation,an evaluation index system was set up,and diary cattle brucellosis risk survey was conducted in 3 typical regions.Finally,systematic multilevel grey relation entropy method was applied to perform data analysis.[Result] The strong-to-weak sequence of Level 1 impact factor of diary cattle brucellosis was as follows：feeding and importinghousingpolyculture situationbreeding;the sequence of Level 2 impact factor was U32〉U12〉U11〉U31〉U21〉U42〉U43〉U23〉U22〉U41;the risk level sequence of 3 typical regions was Province A（County A1,A2,A3）Province B（County B1,B2,B3）Province C（County C1,C2,C3）.[Conclusion] According to the weight of Level 1 index strata,administrative departments at all levels and dairy cattle farmers should lay emphasis on the aspects of feeding,importing and housing;viewed from the perspective of Level 2 index strata,dairy cattle farmers should value the siting of cattle field,the brucellosis surveillance before importing and milking modes most.According to the diary cattle brucellosis risk level of 3 typical regions,if administrative departments at all levels strengthen peoples＇ awareness of their personal health and increase investment in this area,with new healthy cultured atmosphere built,the risk level of diary cattle brucellosis will surly decline.展开更多
Four assessment methods （two pollution indexes and two fuzzy mathematical models） were employed to investigate the environmental quality of four soils around a ferroalloy plant in Nanjing City. Environmental quality...Four assessment methods （two pollution indexes and two fuzzy mathematical models） were employed to investigate the environmental quality of four soils around a ferroalloy plant in Nanjing City. Environmental quality was assessed as class Ⅳ （moderately polluted） for each soil with single-factor index method, and was identified to be classes Ⅳ, Ⅲ （slightly polluted）, Ⅲ, and Ⅲ for soils A, B, C, and D, respectively, with the comprehensive index model. In comparison with the single-factor index method, the comprehensive index model concerned both dominant parameter and average contribution of all factors to the integrated environmental quality. Using the two fuzzy mathematical methods （single-factor deciding and weighted average models）, the environmental risks were determined to be classes Ⅳ, Ⅲ, Ⅱ （clean）, and Ⅱ for soils A, B, C, and D, respectively. However, divergence of the membership degree to each pollution class still occurred between the two methods. In fuzzy mathematical methods, membership functions were used to describe the limits between different pollution degrees, and different weights were allocated for the factors according to pollution contribution. Introduction of membership degree and weight of each factor to fuzzy mathematical models made the methods more reasonable in the field of environmental risk assessment.展开更多
As the air combat environment becomes more complicated and changeable, accurate threat assessment of air target has a significant impact on air defense operations. This paper proposes an improved generalized intuition...As the air combat environment becomes more complicated and changeable, accurate threat assessment of air target has a significant impact on air defense operations. This paper proposes an improved generalized intuitionistic fuzzy soft set (GIFSS) method for dynamic assessment of air target threat. Firstly, the threat assessment index is reasonably determined by analyzing the typical characteristics of air targets. Secondly, after the GIFSS at different time is obtained, the index weight is determined by the intuitionistic fuzzy set entropy and the relative entropy theory. Then, the inverse Poisson distribution method is used to determine the weight of time series, and then the time-weighted GIFSS is obtained. Finally, threat assessment of five air targets is carried out by using the improved GIFSS (I-GIFSS) and comparison methods. The validity and superiority of the proposed method are verified by calculation and comparison.展开更多
Liquid storage tanks are essential structures that are often located in residential and industrial areas; thus an assessment of their seismic performance is an important engineering issue. In this paper, the seismic r...Liquid storage tanks are essential structures that are often located in residential and industrial areas; thus an assessment of their seismic performance is an important engineering issue. In this paper, the seismic response ofunanchored steel liquid storage tanks is investigated using the endurance time （ET） dynamic analysis procedure and compared to responses obtained for anchored tanks under actual ground motions and intensifying ET records. In most cases, the results from ground motions are properly obtained with negligible differences using ET records. It is observed that uplifting of the tank base, which is closely related to the tank aspect ratio, has the greatest significance in the responses of the tank and can be predicted with reasonable accuracy by using currently available ET records.展开更多
Traditional occupational disease control and prevention has remained prevalent in China over recent decades. There are appropriately 30,000 new case reports of occupational diseases annually. Although China has alread...Traditional occupational disease control and prevention has remained prevalent in China over recent decades. There are appropriately 30,000 new case reports of occupational diseases annually. Although China has already established a series of occupational disease prevention programs, occupational health risk assessment （OHRA） strategies continue to be a limitation.展开更多
The core of network security is the risk assessment. In this letter,a risk assessment method is introduced to estimate the wireless network security. The method,which combines Analytic Hier-archy Process (AHP) method ...The core of network security is the risk assessment. In this letter,a risk assessment method is introduced to estimate the wireless network security. The method,which combines Analytic Hier-archy Process (AHP) method and fuzzy logical method,is applied to the risk assessment. Fuzzy logical method is applied to judge the important degree of each factor in the aspects of the probability,the influence and the uncontrollability,not to directly judge the important degree itself. The risk as-sessment is carved up 3 layers applying AHP method,the sort weight of the third layer is calculated by fuzzy logical method. Finally,the important degree is calculated by AHP method. By comparing the important degree of each factor,the risk which can be controlled by taking measures is known. The study of the case shows that the method can be easily used to the risk assessment of the wireless network security and its results conform to the actual situation.展开更多
It is widely recognized that assessments of the status of data-poor fish stocks are challenging and that Bayesian analysis is one of the methods which can be used to improve the reliability of stock assessments in dat...It is widely recognized that assessments of the status of data-poor fish stocks are challenging and that Bayesian analysis is one of the methods which can be used to improve the reliability of stock assessments in data-poor situations through borrowing strength from prior information deduced from species with good-quality data or other known information. Because there is considerable uncertainty remaining in the stock assessment of albacore tuna（Thunnus alalunga） in the Indian Ocean due to the limited and low-quality data, we investigate the advantages of a Bayesian method in data-poor stock assessment by using Indian Ocean albacore stock assessment as an example. Eight Bayesian biomass dynamics models with different prior assumptions and catch data series were developed to assess the stock. The results show（1） the rationality of choice of catch data series and assumption of parameters could be enhanced by analyzing the posterior distribution of the parameters;（2） the reliability of the stock assessment could be improved by using demographic methods to construct a prior for the intrinsic rate of increase（r）. Because we can make use of more information to improve the rationality of parameter estimation and the reliability of the stock assessment compared with traditional statistical methods by incorporating any available knowledge into the informative priors and analyzing the posterior distribution based on Bayesian framework in data-poor situations, we suggest that the Bayesian method should be an alternative method to be applied in data-poor species stock assessment, such as Indian Ocean albacore.展开更多
Hazard factors, hazard-bearling objects, disaster-developing environment, and disaster-preventing capability play key roles in the formation of Tropical Cyclone （TC） disasters. Of all of these, the most important is...Hazard factors, hazard-bearling objects, disaster-developing environment, and disaster-preventing capability play key roles in the formation of Tropical Cyclone （TC） disasters. Of all of these, the most important is the intensity of hazard factors （risk sources）. In this study, this intensity is uniformly defined by the probability of hazard factors; then a relationship is established between disaster risk intensity and hazard factors. The exceedance probability of various hazard factors, including frequency and timing, scope of wind and rain, and maximum wind and rain of impacting TC cases, are calculated using data from TCs that impacted Shanghai fi＇om 1959-2006. The relationship between disaster situation and risk probability of hazard factors is analyzed, and the indices and model of TC disaster assessment are established based on the results. The process maximum wind speed and maximum daily precipitation are very important in TC-related disaster formation in Shanghai. The results of disaster indices coordinate with the results of the assessment model, and both can show the extent of probability of a TC disaster. Tests using TC data in 2007 and 2008 show that disasters caused by TC Krosa （0716） would be more serious than those by TC Wipha （0713）, and that TC Fung Wong （0808） would have a weak impact. Real-life situations validate these results.展开更多
The exploitation status of wind energy resources was analyzed, and the distribution of wind energy resources and regional meteorological stations were introduced, and then the assessment method of wind energy resource...The exploitation status of wind energy resources was analyzed, and the distribution of wind energy resources and regional meteorological stations were introduced, and then the assessment method of wind energy resources by using data from regional meteorological station was studied taking Huangjin Regional Meteorological Station in Xinning County in Hunan Province for example, besides, corresponding software was compiled. By means of SQL database and program, the method was used simply and easily and had positive meaning for the development of wind energy resources and excavation of wind farm in inland region.展开更多
Assessment of acid sulfate soil risk is an important step for acid sulfate soil management and its reliability depends very much on the suitability and accuracy of various analytical methods for estimating sulfide-der...Assessment of acid sulfate soil risk is an important step for acid sulfate soil management and its reliability depends very much on the suitability and accuracy of various analytical methods for estimating sulfide-derived potential acidity, actual acidity and acid-neutralizing capacity in acid sulfate soils. This paper critically reviews various analytical methods that are currently used for determination of the above parameters, as well as their implications for environmental risk assessment of acid sulfate soi1s.展开更多
Fatigue strength assessment of a horizontal axis wind turbine(HAWT)composite blade is considered.Fatigue load cases are identified,and loads are calculated by the GH Bladed software which is specified at the IEC61400 ...Fatigue strength assessment of a horizontal axis wind turbine(HAWT)composite blade is considered.Fatigue load cases are identified,and loads are calculated by the GH Bladed software which is specified at the IEC61400 international specification and GL(Germanisher Lloyd)regulations for the wind energy conversion system.Stress analysis is performed with a 3-D finite element method(FEM).Considering Saint-Venant′s principle,a uniform cross section FEM model is built at each critical zone.Stress transformation matrixes(STM)are set up by applied six unit load components on the FEM model separately.STM can be used to convert the external load into stresses in the linear elastic range.The main material of composite wind turbine blade is fiber reinforced plastics(FRP).In order to evaluate the degree of fatigue damage of FRP,the stresses of fiber direction are extracted and the well-known strength criterion-Puck theory is used.The total fatigue damage of each laminate on the critical point is counted by the rain-flow counting method and Miner′s damage law based on general S-N curves.Several sections of a 45.3mblade of a 2 MW wind turbine are studied using the fatigue evaluation method.The performance of this method is compared with far more costly business software FOCUS.The results show that the fatigue damage of multi-axis FRP can be assessed conveniently by the FEM-STM method.And the proposed method gives a reliable and efficient method to analyze the fatigue damage of slender composite structure with variable cross-sections.展开更多
Monte-Carlo method is used for estimating coalbed methane （CBM） resources in key coal mining areas of China. Monte-Carlo method is shown to be superior to the traditional volumetric method with constant parameters i...Monte-Carlo method is used for estimating coalbed methane （CBM） resources in key coal mining areas of China. Monte-Carlo method is shown to be superior to the traditional volumetric method with constant parameters in the calculation of CBM resources. The focus of the article is to introduce the main algorithm and the realization of functions estimated by Monte-Carlo method, including selection of parameters, determination of distribution function, generation of pseudo-random numbers, and evaluation of the parameters corresponding to pseudo-random numbers. A specified software on the basis of Monte-Carlo method is developed using Visual C＋＋ for the assessment of the CBM resources. A case study shows that calculation results using Monte-Carlo method have smaller error range in comparison with those using volumetric method.展开更多
In recent years,the ecological environment along highways in Tibetan Plateau has been severely affected due to the rapid construction of highways.In order to solve the problems of multiple indicators and inconsistent ...In recent years,the ecological environment along highways in Tibetan Plateau has been severely affected due to the rapid construction of highways.In order to solve the problems of multiple indicators and inconsistent criteria in the ecological impact assessment of highways,and to scientifically screen assessment indicators,the paper proposes a multi-round indicator screening method,which combines literature analysis,expert rating,and statistical analysis.Based on this screening method,normalized difference vegetation index,land surface temperature,elevation,and normalized difference soil index are screened out.Combined with multiple linear regression,an ecological impact assessment model is established and applied to ecological impact assessment of Gonghe-Yushu Expressway.The results show that the expressway construction is the first driving force for the deterioration of the ecological environment along the roadside,and its interference range on the desert grassland ecosystem is greater than that on the agroforestry system.The ecological environment within 150 m on both sides of the expressway should be protected.展开更多
The existence of inclusion influences the properties of aluminum alloy castings,from which the castings will face scrapping under severe condition.Great efforts on the inclusions in aluminum alloy were made and many i...The existence of inclusion influences the properties of aluminum alloy castings,from which the castings will face scrapping under severe condition.Great efforts on the inclusions in aluminum alloy were made and many inclusion assessment methods were put forward.However,most of the current methods are characterized by time consuming and expensive equipment cost,which limits the application in aluminum industry.Since the aluminum properties are sensitive to the inclusion,this paper tries to establish a new kind of inclusion assessment method.The inclusions were introduced to aluminum melts by adding aluminum scraps.The samples with different inclusion contents were prepared.The microstructure contained inclusions was observed.The inclusion was automatically identified with an image analyzer by setting different grey threshold value,and the inclusion content was obtained.The image analysis shows that inclusions wreck the continuity of the alloy matrix seriously,and the inclusion area percentage increases with the increasing of aluminum scraps.The high and low polarization measurements were conducted in 3.5 wt% NaCl aqueous solution at the temperature of 25 ℃.The electrochemical parameters of the testing materials,such as corrosion potential E k,corrosion current density I k and the linear polarization resistance R p,were obtained.The polarization measurement results show that the linear polarization resistances decrease,the corrosion potentials move towards more negative direction,and the corrosion current densities increase with the increasing of inclusion content.The theoretical analysis of the inclusion content and the corrosion current density was performed.The existence of inclusions makes the microstructure form corrosion microcells between the alloy matrix and inclusions.The impressed current can accelerate the current velocity or corrosion current density.The regression model of the inclusion contents vs.the corrosion current density was obtained.This model can be used to quantitatively analyze the inclusion content in aluminum alloys on the basis of inclusion sensitivity to the inclusion content.It is confirmed that the electrochemical method for inclusion assessment （EcMIA） is simple and reliable,which can provide a new solution for inclusion assessment in aluminum alloy.展开更多
An MW6.6 earthquake occurred in eastern Hokkaido,Japan on September 6th,2018.Based on the pre-earthquake image from Google Earth and the post-earthquake image from high resolution(3 m)planet satellite,we manually inte...An MW6.6 earthquake occurred in eastern Hokkaido,Japan on September 6th,2018.Based on the pre-earthquake image from Google Earth and the post-earthquake image from high resolution(3 m)planet satellite,we manually interpret 9293 coseismic landslides and select 7 influencing factors of seismic landslide,such as elevation,slope,slope direction,road distance,flow distance,peak ground acceleration(PGA)and lithology.Then,9293 landslide points are randomly divided into training samples and validation samples with a proportion of 7:3.In detail,the training sample has 6505 landslide points and the validation sample has 2788 landslide points.The hazard risk assessment of seismic landslide is conducted by using the information value method and the study area is further divided into five risk grades,including very low risk area,low risk area,moderate risk area high risk area and very high risk area.The results show that there are 7576 landslides in high risk area and very high risk area,accounting for81.52%of the total landslide number,and the landslide area is 22.93 km^2,accounting for 74.35%of the total area.The hazard zoning is in high accordance with the actual situation.The evaluation results are tested by using the curve of cumulative percentage of hazardous area and cumulative percentage of landslides number.The results show that the success rate of the information value method is 78.50%and the prediction rate is 78.43%.The evaluation results are satisfactory,indicating that the hazard risk assessment results based on information value method may provide scientific reference for landslide hazard risk assessment as well as the disaster prevention and mitigation in the study area.展开更多
The achievement progresses of investigation and studies on marine hazardous geology are summarized and presentsd in the late 20 century in China. The importance, research value and present-day studies of marine hazard...The achievement progresses of investigation and studies on marine hazardous geology are summarized and presentsd in the late 20 century in China. The importance, research value and present-day studies of marine hazardous geology, a newly developing branch of geoscience, are well expatiated. Several often confused concepts and theories are explained and redefined here. The comment on the means of investigations, assessment of marine hazardous geology, as well as its evolution, innovation, existing questions and future tasks are also introduced and presented. The concepts of 'hazard geology', geohazard', 'map of marine hazard geology', 'integrated evaluaton on seafloor stablity' are respectively discussed, including their definition, research objects, methods and contents. The types and classification of marine hazardous geology, principles and methods of marine hazardous geology map compilation, the assessment methods and models of marine hazardous geology environment and seafloor stability and so on are also discussed.展开更多
Running safety assessment and tracking irregularity parametric sensitivity analysis of high-speed maglev train-bridge system are of great concern,especially need perfect refinement models in which all properties can b...Running safety assessment and tracking irregularity parametric sensitivity analysis of high-speed maglev train-bridge system are of great concern,especially need perfect refinement models in which all properties can be well characterized based on various stochastic excitations.A three-dimensional refined spatial random vibration analysis model of high-speed maglev train-bridge coupled system is established in this paper,in which multi-source uncertainty excitation can be considered simultaneously,and the probability density evolution method(PDEM)is adopted to reveal the system-specific uncertainty dynamic characteristic.The motion equation of the maglev vehicle model is composed of multi-rigid bodies with a total 210-degrees of freedom for each vehicle,and a refined electromagnetic force-air gap model is used to account for the interaction and coupling effect between the moving train and track beam bridges,which are directly established by using finite element method.The model is proven to be applicable by comparing with Monte Carlo simulation.By applying the proposed stochastic framework to the high maglev line,the random dynamic responses of maglev vehicles running on the bridges are studied for running safety and stability assessment.Moreover,the effects of track irregularity wavelength range under different amplitude and running speeds on the coupled system are investigated.The results show that the augmentation of train speed will move backward the sensitive wavelength interval,and track irregularity amplitude influences the response remarkably in the sensitive interval.展开更多
文摘The evaluation of the electricity market is crucial for fostering market construction and development.An accurate assessment of the electricity market reveals developmental trends,identifies operational issues,and contributes to stable and healthy market growth.This study investigated the characteristics of electricity markets in different provinces and synthesized a comprehensive set of evaluation indicators to assess market effectiveness.The evaluation framework,comprising nine indicators organized into two tiers,was constructed based on three aspects:market design,market efficiency,and developmental coordination.Furthermore,a novel fuzzy multi-criteria decision-making evaluation model for electricity market performance was developed based on the Fuzzy-BWM and fuzzy COPRAS methodologies.This model aimed to ensure both accuracy and comprehensiveness in market operation assessment.Subsequently,empirical analyses were conducted on four typical provincial-level electricity markets in China.The results indicate that Guangdong’s electricity market performed best because of its effective balance of stakeholder interests and adherence to contractual integrity principles.Zhejiang and Shandong ranked second and third,respectively,whereas Sichuan exhibited the poorest market performance.Sichuan’s electricity market must be improved in terms of market design,such that market players can obtain a fairly competitive environment.The sensitivity analysis of the constructed indicators verified the effectiveness of the evaluation model proposed in this study.Finally,policy recommendations were proposed to facilitate the sustainable development of China’s electricity markets with the objective of transforming them into efficient and secure markets adaptable to the evolution of novel power systems.
文摘Objective:To explore the application effect of video assessment method in clinical nurses’nursing operation skills.Method:To select 58 nurses who participated in the individual soldier standard in the children’s hospital in 2019 and 2020 as the research objects,among which the nurses who participated in the individual soldier standard in 2019 were the nurses who participated in the individual soldier standard in 2019 and 2020.A total of 29 people in the first batch were set as the control group,using traditional assessment methods.In 2020,the second batch of 29 nurses who participated in the individual soldier standard reached the experimental group.Using the video assessment method,there was no significant difference in general information between the two groups(P>0.05).After the assessment,the scores,coping with work pressure,and proactiveness of the two groups of research subjects were compared.Results:The experimental group’s nursing operation assessment scores,coping with work pressure,and proactiveness were significantly better than those of the control group,the difference was statistically significant(P<0.05).Conclusion:The application of the video assessment method improves the passing rate of nurses’operational skills examination,enhances nurses’initiative in learning,reduces examination pressure,and can be accurately,timely,and safely applied to clinical nursing work,which is worthy of study and promotion.
基金Supported by Special Research Fund for Public Sector(Agriculture)(200903055)~~
文摘[Objective] The study was to explore the major factors affecting diary cattle brucellosis risk assessment,as well as their strong-to-weak sequence,so as to provide theoretical basis for assessing diary cattle brucellosis risk level in different regions.[Method] From 4 dimensions of feeding and importing,breeding,housing and polyculture situation,an evaluation index system was set up,and diary cattle brucellosis risk survey was conducted in 3 typical regions.Finally,systematic multilevel grey relation entropy method was applied to perform data analysis.[Result] The strong-to-weak sequence of Level 1 impact factor of diary cattle brucellosis was as follows：feeding and importinghousingpolyculture situationbreeding;the sequence of Level 2 impact factor was U32〉U12〉U11〉U31〉U21〉U42〉U43〉U23〉U22〉U41;the risk level sequence of 3 typical regions was Province A（County A1,A2,A3）Province B（County B1,B2,B3）Province C（County C1,C2,C3）.[Conclusion] According to the weight of Level 1 index strata,administrative departments at all levels and dairy cattle farmers should lay emphasis on the aspects of feeding,importing and housing;viewed from the perspective of Level 2 index strata,dairy cattle farmers should value the siting of cattle field,the brucellosis surveillance before importing and milking modes most.According to the diary cattle brucellosis risk level of 3 typical regions,if administrative departments at all levels strengthen peoples＇ awareness of their personal health and increase investment in this area,with new healthy cultured atmosphere built,the risk level of diary cattle brucellosis will surly decline.
基金the PhD Fund of the National Education Ministry of China (No20030284038)the Interna-tional Foundation for Science (NoW/4215)
文摘Four assessment methods （two pollution indexes and two fuzzy mathematical models） were employed to investigate the environmental quality of four soils around a ferroalloy plant in Nanjing City. Environmental quality was assessed as class Ⅳ （moderately polluted） for each soil with single-factor index method, and was identified to be classes Ⅳ, Ⅲ （slightly polluted）, Ⅲ, and Ⅲ for soils A, B, C, and D, respectively, with the comprehensive index model. In comparison with the single-factor index method, the comprehensive index model concerned both dominant parameter and average contribution of all factors to the integrated environmental quality. Using the two fuzzy mathematical methods （single-factor deciding and weighted average models）, the environmental risks were determined to be classes Ⅳ, Ⅲ, Ⅱ （clean）, and Ⅱ for soils A, B, C, and D, respectively. However, divergence of the membership degree to each pollution class still occurred between the two methods. In fuzzy mathematical methods, membership functions were used to describe the limits between different pollution degrees, and different weights were allocated for the factors according to pollution contribution. Introduction of membership degree and weight of each factor to fuzzy mathematical models made the methods more reasonable in the field of environmental risk assessment.
基金supported by the National Natural Science Foundation of China(51779263)
文摘As the air combat environment becomes more complicated and changeable, accurate threat assessment of air target has a significant impact on air defense operations. This paper proposes an improved generalized intuitionistic fuzzy soft set (GIFSS) method for dynamic assessment of air target threat. Firstly, the threat assessment index is reasonably determined by analyzing the typical characteristics of air targets. Secondly, after the GIFSS at different time is obtained, the index weight is determined by the intuitionistic fuzzy set entropy and the relative entropy theory. Then, the inverse Poisson distribution method is used to determine the weight of time series, and then the time-weighted GIFSS is obtained. Finally, threat assessment of five air targets is carried out by using the improved GIFSS (I-GIFSS) and comparison methods. The validity and superiority of the proposed method are verified by calculation and comparison.
文摘Liquid storage tanks are essential structures that are often located in residential and industrial areas; thus an assessment of their seismic performance is an important engineering issue. In this paper, the seismic response ofunanchored steel liquid storage tanks is investigated using the endurance time （ET） dynamic analysis procedure and compared to responses obtained for anchored tanks under actual ground motions and intensifying ET records. In most cases, the results from ground motions are properly obtained with negligible differences using ET records. It is observed that uplifting of the tank base, which is closely related to the tank aspect ratio, has the greatest significance in the responses of the tank and can be predicted with reasonable accuracy by using currently available ET records.
基金supported by the Natural Science Foundation of China(81472961)the Joint Projects of the National Health and Family Planning Commission of China and the Health Bureau of Zhejiang Province(No.WSK 2014-2-004)the Zhejiang Provincial Program for the Cultivation of High-Level Innovative Health Talents
文摘Traditional occupational disease control and prevention has remained prevalent in China over recent decades. There are appropriately 30,000 new case reports of occupational diseases annually. Although China has already established a series of occupational disease prevention programs, occupational health risk assessment （OHRA） strategies continue to be a limitation.
基金the National Natural Science Foundation of China (No.60573036).
文摘The core of network security is the risk assessment. In this letter,a risk assessment method is introduced to estimate the wireless network security. The method,which combines Analytic Hier-archy Process (AHP) method and fuzzy logical method,is applied to the risk assessment. Fuzzy logical method is applied to judge the important degree of each factor in the aspects of the probability,the influence and the uncontrollability,not to directly judge the important degree itself. The risk as-sessment is carved up 3 layers applying AHP method,the sort weight of the third layer is calculated by fuzzy logical method. Finally,the important degree is calculated by AHP method. By comparing the important degree of each factor,the risk which can be controlled by taking measures is known. The study of the case shows that the method can be easily used to the risk assessment of the wireless network security and its results conform to the actual situation.
基金The Innovation Program of Shanghai Municipal Education Commission under contract No.14ZZ147the Opening Project of Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources(Shanghai Ocean University),Ministry of Education under contract No.A1-0209-15-0503-1
文摘It is widely recognized that assessments of the status of data-poor fish stocks are challenging and that Bayesian analysis is one of the methods which can be used to improve the reliability of stock assessments in data-poor situations through borrowing strength from prior information deduced from species with good-quality data or other known information. Because there is considerable uncertainty remaining in the stock assessment of albacore tuna（Thunnus alalunga） in the Indian Ocean due to the limited and low-quality data, we investigate the advantages of a Bayesian method in data-poor stock assessment by using Indian Ocean albacore stock assessment as an example. Eight Bayesian biomass dynamics models with different prior assumptions and catch data series were developed to assess the stock. The results show（1） the rationality of choice of catch data series and assumption of parameters could be enhanced by analyzing the posterior distribution of the parameters;（2） the reliability of the stock assessment could be improved by using demographic methods to construct a prior for the intrinsic rate of increase（r）. Because we can make use of more information to improve the rationality of parameter estimation and the reliability of the stock assessment compared with traditional statistical methods by incorporating any available knowledge into the informative priors and analyzing the posterior distribution based on Bayesian framework in data-poor situations, we suggest that the Bayesian method should be an alternative method to be applied in data-poor species stock assessment, such as Indian Ocean albacore.
基金National Basic Research Program of China or 973 Program (2009CB421505)Shanghai Key Agricultural Projects (Hu Nong Ke 2006-4-10)
文摘Hazard factors, hazard-bearling objects, disaster-developing environment, and disaster-preventing capability play key roles in the formation of Tropical Cyclone （TC） disasters. Of all of these, the most important is the intensity of hazard factors （risk sources）. In this study, this intensity is uniformly defined by the probability of hazard factors; then a relationship is established between disaster risk intensity and hazard factors. The exceedance probability of various hazard factors, including frequency and timing, scope of wind and rain, and maximum wind and rain of impacting TC cases, are calculated using data from TCs that impacted Shanghai fi＇om 1959-2006. The relationship between disaster situation and risk probability of hazard factors is analyzed, and the indices and model of TC disaster assessment are established based on the results. The process maximum wind speed and maximum daily precipitation are very important in TC-related disaster formation in Shanghai. The results of disaster indices coordinate with the results of the assessment model, and both can show the extent of probability of a TC disaster. Tests using TC data in 2007 and 2008 show that disasters caused by TC Krosa （0716） would be more serious than those by TC Wipha （0713）, and that TC Fung Wong （0808） would have a weak impact. Real-life situations validate these results.
文摘The exploitation status of wind energy resources was analyzed, and the distribution of wind energy resources and regional meteorological stations were introduced, and then the assessment method of wind energy resources by using data from regional meteorological station was studied taking Huangjin Regional Meteorological Station in Xinning County in Hunan Province for example, besides, corresponding software was compiled. By means of SQL database and program, the method was used simply and easily and had positive meaning for the development of wind energy resources and excavation of wind farm in inland region.
文摘Assessment of acid sulfate soil risk is an important step for acid sulfate soil management and its reliability depends very much on the suitability and accuracy of various analytical methods for estimating sulfide-derived potential acidity, actual acidity and acid-neutralizing capacity in acid sulfate soils. This paper critically reviews various analytical methods that are currently used for determination of the above parameters, as well as their implications for environmental risk assessment of acid sulfate soi1s.
基金supported jointly by the National Basic Research Program of China(″973″Program)(No.2014CB046200)the Natural Science Foundation of Jiangsu Province(No.BK2014059)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe National Natural Science Foundation of China(No.11172135)
文摘Fatigue strength assessment of a horizontal axis wind turbine(HAWT)composite blade is considered.Fatigue load cases are identified,and loads are calculated by the GH Bladed software which is specified at the IEC61400 international specification and GL(Germanisher Lloyd)regulations for the wind energy conversion system.Stress analysis is performed with a 3-D finite element method(FEM).Considering Saint-Venant′s principle,a uniform cross section FEM model is built at each critical zone.Stress transformation matrixes(STM)are set up by applied six unit load components on the FEM model separately.STM can be used to convert the external load into stresses in the linear elastic range.The main material of composite wind turbine blade is fiber reinforced plastics(FRP).In order to evaluate the degree of fatigue damage of FRP,the stresses of fiber direction are extracted and the well-known strength criterion-Puck theory is used.The total fatigue damage of each laminate on the critical point is counted by the rain-flow counting method and Miner′s damage law based on general S-N curves.Several sections of a 45.3mblade of a 2 MW wind turbine are studied using the fatigue evaluation method.The performance of this method is compared with far more costly business software FOCUS.The results show that the fatigue damage of multi-axis FRP can be assessed conveniently by the FEM-STM method.And the proposed method gives a reliable and efficient method to analyze the fatigue damage of slender composite structure with variable cross-sections.
基金supported by the National Natural Science Foundation of China (No. 40730422)the Foundation of China University of Mining & Technology (No. OF061003)State Key Laboratory of Geological Processes and Mineral Resources (No. GPMR2007-11)
文摘Monte-Carlo method is used for estimating coalbed methane （CBM） resources in key coal mining areas of China. Monte-Carlo method is shown to be superior to the traditional volumetric method with constant parameters in the calculation of CBM resources. The focus of the article is to introduce the main algorithm and the realization of functions estimated by Monte-Carlo method, including selection of parameters, determination of distribution function, generation of pseudo-random numbers, and evaluation of the parameters corresponding to pseudo-random numbers. A specified software on the basis of Monte-Carlo method is developed using Visual C＋＋ for the assessment of the CBM resources. A case study shows that calculation results using Monte-Carlo method have smaller error range in comparison with those using volumetric method.
基金supported by the National Natural Science Foundation of China(NSFC)(No.41801387)。
文摘In recent years,the ecological environment along highways in Tibetan Plateau has been severely affected due to the rapid construction of highways.In order to solve the problems of multiple indicators and inconsistent criteria in the ecological impact assessment of highways,and to scientifically screen assessment indicators,the paper proposes a multi-round indicator screening method,which combines literature analysis,expert rating,and statistical analysis.Based on this screening method,normalized difference vegetation index,land surface temperature,elevation,and normalized difference soil index are screened out.Combined with multiple linear regression,an ecological impact assessment model is established and applied to ecological impact assessment of Gonghe-Yushu Expressway.The results show that the expressway construction is the first driving force for the deterioration of the ecological environment along the roadside,and its interference range on the desert grassland ecosystem is greater than that on the agroforestry system.The ecological environment within 150 m on both sides of the expressway should be protected.
基金supported by National Natural Science Foundation of China(Grant No.50864002)Guangxi Provincial Natural Science Foundation of China(Grant No.0991001)Natural Science Foundation of Guangxi University of China(Grant No.X071081)
文摘The existence of inclusion influences the properties of aluminum alloy castings,from which the castings will face scrapping under severe condition.Great efforts on the inclusions in aluminum alloy were made and many inclusion assessment methods were put forward.However,most of the current methods are characterized by time consuming and expensive equipment cost,which limits the application in aluminum industry.Since the aluminum properties are sensitive to the inclusion,this paper tries to establish a new kind of inclusion assessment method.The inclusions were introduced to aluminum melts by adding aluminum scraps.The samples with different inclusion contents were prepared.The microstructure contained inclusions was observed.The inclusion was automatically identified with an image analyzer by setting different grey threshold value,and the inclusion content was obtained.The image analysis shows that inclusions wreck the continuity of the alloy matrix seriously,and the inclusion area percentage increases with the increasing of aluminum scraps.The high and low polarization measurements were conducted in 3.5 wt% NaCl aqueous solution at the temperature of 25 ℃.The electrochemical parameters of the testing materials,such as corrosion potential E k,corrosion current density I k and the linear polarization resistance R p,were obtained.The polarization measurement results show that the linear polarization resistances decrease,the corrosion potentials move towards more negative direction,and the corrosion current densities increase with the increasing of inclusion content.The theoretical analysis of the inclusion content and the corrosion current density was performed.The existence of inclusions makes the microstructure form corrosion microcells between the alloy matrix and inclusions.The impressed current can accelerate the current velocity or corrosion current density.The regression model of the inclusion contents vs.the corrosion current density was obtained.This model can be used to quantitatively analyze the inclusion content in aluminum alloys on the basis of inclusion sensitivity to the inclusion content.It is confirmed that the electrochemical method for inclusion assessment （EcMIA） is simple and reliable,which can provide a new solution for inclusion assessment in aluminum alloy.
基金supported by the BasicScientific Fund of the Institute of Geology,China Earthquake Administration(IGCEA1604)。
文摘An MW6.6 earthquake occurred in eastern Hokkaido,Japan on September 6th,2018.Based on the pre-earthquake image from Google Earth and the post-earthquake image from high resolution(3 m)planet satellite,we manually interpret 9293 coseismic landslides and select 7 influencing factors of seismic landslide,such as elevation,slope,slope direction,road distance,flow distance,peak ground acceleration(PGA)and lithology.Then,9293 landslide points are randomly divided into training samples and validation samples with a proportion of 7:3.In detail,the training sample has 6505 landslide points and the validation sample has 2788 landslide points.The hazard risk assessment of seismic landslide is conducted by using the information value method and the study area is further divided into five risk grades,including very low risk area,low risk area,moderate risk area high risk area and very high risk area.The results show that there are 7576 landslides in high risk area and very high risk area,accounting for81.52%of the total landslide number,and the landslide area is 22.93 km^2,accounting for 74.35%of the total area.The hazard zoning is in high accordance with the actual situation.The evaluation results are tested by using the curve of cumulative percentage of hazardous area and cumulative percentage of landslides number.The results show that the success rate of the information value method is 78.50%and the prediction rate is 78.43%.The evaluation results are satisfactory,indicating that the hazard risk assessment results based on information value method may provide scientific reference for landslide hazard risk assessment as well as the disaster prevention and mitigation in the study area.
文摘The achievement progresses of investigation and studies on marine hazardous geology are summarized and presentsd in the late 20 century in China. The importance, research value and present-day studies of marine hazardous geology, a newly developing branch of geoscience, are well expatiated. Several often confused concepts and theories are explained and redefined here. The comment on the means of investigations, assessment of marine hazardous geology, as well as its evolution, innovation, existing questions and future tasks are also introduced and presented. The concepts of 'hazard geology', geohazard', 'map of marine hazard geology', 'integrated evaluaton on seafloor stablity' are respectively discussed, including their definition, research objects, methods and contents. The types and classification of marine hazardous geology, principles and methods of marine hazardous geology map compilation, the assessment methods and models of marine hazardous geology environment and seafloor stability and so on are also discussed.
基金Project(2023YFB4302500)supported by the National Key R&D Program of ChinaProject(52078485)supported by the National Natural Science Foundation of ChinaProjects(2021-Major-16,2021-Special-08)supported by the Science and Technology Research and Development Program Project of China Railway Group Limited。
文摘Running safety assessment and tracking irregularity parametric sensitivity analysis of high-speed maglev train-bridge system are of great concern,especially need perfect refinement models in which all properties can be well characterized based on various stochastic excitations.A three-dimensional refined spatial random vibration analysis model of high-speed maglev train-bridge coupled system is established in this paper,in which multi-source uncertainty excitation can be considered simultaneously,and the probability density evolution method(PDEM)is adopted to reveal the system-specific uncertainty dynamic characteristic.The motion equation of the maglev vehicle model is composed of multi-rigid bodies with a total 210-degrees of freedom for each vehicle,and a refined electromagnetic force-air gap model is used to account for the interaction and coupling effect between the moving train and track beam bridges,which are directly established by using finite element method.The model is proven to be applicable by comparing with Monte Carlo simulation.By applying the proposed stochastic framework to the high maglev line,the random dynamic responses of maglev vehicles running on the bridges are studied for running safety and stability assessment.Moreover,the effects of track irregularity wavelength range under different amplitude and running speeds on the coupled system are investigated.The results show that the augmentation of train speed will move backward the sensitive wavelength interval,and track irregularity amplitude influences the response remarkably in the sensitive interval.
