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Risk assessment on the drainage pipe network based on the AHP-entropy weight method
LIU Wei;DONG Wan-qi;The paper presents a combination weighing method to assess the risk levels of drainage pipe networks. The method is novel for drainage pipe network risk assessment and suitable for China national context of actual situation. The combination weighting method,including the entropy weight which considers objective influence and AHP weight which considers subjective influence,is introduced. Meanwhile,a risk index system of the drainage pipe networks is built up. And,such the index system includes the accident possibility index and the accident consequence index. Herein,the accident possibility index actually consists of two parts,namely,the pipeline vulnerability and the accident cause indexes. All the indexes involved are introduced in detail with corresponding scores are given for these indexes Then,a risk matrix is introduced to assess the risk level of the drainage pipe network. The matrix classifies risk into five risk levels,i. e. lowest,lower,medium,higher and highest levels.An actual drainage network is used as an example to validate the risk assessment method. After risk assessment,15. 1%,69. 2% and 15. 7% pipes are in the level of lowest,lower and medium levels,respectively. The risk assessment can be used as a guidance for the management of the drainage company. Moreover,the recalling ratio of example network is 91. 35%,which validate the feasibility and effectivity of the proposed method.
On influential factors and regional difference in carbon emissions from power industry at home in China
HE Ying;XING Yuan-tong;JI Yi-jun;ZHANG Lei;This paper intends to explore the driving force and the inhibiting factors as well as the control strategies of the carbon emissions from the power industry( short for CEPI) at home in China. In the paper,the author has examined 7 influential factors on the evolution of CEPI and gained the contributive value and the contribution rate of each factor via the Logarithmic Mean Divisia Index( LMDI). It is through the 4-quadrant method that has made us succeed in finding the disparities of the 4 major influential factors in the 30 provinces and autonomous regions.The results of the above study demonstrate that:( 1) In the period of 2005 to 2016,CEPI has generally been revealing an increasing trend with a growth rate of 88. 02%,thus getting to the peak in 2013,though the intensity of CEPI indicates a downward trend with a reduction rate of 23. 47%;( 2) The economic scale factor has been serving as the dominant driving force for the increase of CEPI,whereas its cumulative contribution data tends to be 3 096. 05 Mt with a contribution rate being 166. 02%. And,meanwhile,the energy intensity of the thermal power,the powergenerating structure,and the power intensity of GDP tend to be the main inhibiting factors with the cumulative contributive data being respectively of-593. 37 Mt,-468. 33 Mt,-244. 73 Mt and their contributive rates being-31. 82%,-25. 11% and-13. 12%,respectively;( 3) The 4 major influential factors have great regional differences. And,so,the national reduction strategies of CEPI have to be implemented according to the particular features of each province. For instance,the provinces like Guizhou and Yunnan should be paid attention to the adjustment of the growth rates of GDP and the emphasis on "high quality",especially,in their restricted developing areas and prohibited development areas. The Inner Mongolia autonomous region and Heilongjiang Province should be focused on reducing energy intensity of the thermal power and minimizing the proportion of the thermal power,while in provinces and autonomous regions,like Ningxia and Xinjiang,stress ought to be put on decreasing the power consumption per unit of GDP. Thus,it can be found that the given paper intends to provide for profound insights and suggestions on the proper control of China's CEPI as well as the efficient application of the natural resources in a comprehensive policy-making view.
Optimization of dynamic medical supplies distribution considering COVID-19's diffusion rule
JIANG Yang-sheng;HAN Jia-zhe;ZHU Juan-xiu;HU Lu;LUO Ran;Combined with the Susceptible-Exposed-Infected-Asymptomatic-Recovered(SEIAR) model, this study proposes a multi-objective dynamic optimization model for emergency resource allocation. The proposed model determines the quantity and delivery time of medical resources transported from distribution centers to the epidemic areas and the resource replenishment quantity for distribution centers, aiming at minimizing the number of infected persons and the number of vehicles. A periodic rolling decision-making is applied to meet the changing needs due to the development of the epidemic. Because the time granularity used in this paper is small and the number of variables is large, to improve the efficiency of the solution, a two-stage optimization method combining the Simultaneous Perturbation Stochastic Approximation(SPSA) and the Large-scale Neighborhood Search(LNS) algorithm is proposed to solve the multi-objective model based on the design of the system state iteration algorithm. Applying actual data from Wuhan in 2020, the proposed method is compared with existing allocation strategies to verify its effectiveness and feasibility. The results show that the algorithm used in this paper can solve the model in a relatively short time, and the trend of the epidemic situation predicted in this paper is in line with the actual situation. The proposed optimization model is superior to the existing strategies in reducing the number of infected people and the number of vehicles. Compared with other strategies, the optimization model proposed in this paper can effectively reduce 13.9%-40.0% of infection cases and 17.6%-30.0% of scheduled vehicles, and the method proposed in this paper can have a good effect in the case of insufficient vehicles. Owing to the periodic rolling decision, the proposed method effectively avoids the phenomenon of the overstock of medical materials in the distribution center at the later stage, which is a serious problem during the Wuhan epidemic in 2020.
RESEARCH SURVEY OF ECO-INDUSTRIAL PARKS IN SEVERAL COUNTRIES
DENG Nan sheng & WU Feng (Department of Environmental Science, Wuhan University, Wuhan 430072, China)In the present paper,the research improvement of the eco industrial parks in several countries is briefly reviewed. As embryo of eco industrial park,Kalundborg Industrial Symbiosis is introduced.Its environmental and economic benefits per year are presented (Table 1).The definition and the development model of eco industrial park is discussed.And the key steps to setup eco industrial park are also described.The characteristics of some eco industrial parks located in United States (Table 2) and Canada (Table 3) are introduced and summarized.
Research status in-situ of hydrogen safety
ZHENG Jin-yang;ZHANGJun-feng;CHEN Lin-xin;WANG Geng;GU Chao-hua;ZHAO Yong-zhi;LIU Peng-fei;ZHANG Xin;MENG Bo;Institute of Process Equipment,Zhejiang University;High-pressure Process Equipment and Safety Engineering Research Center of Ministry of Education;State Key Laboratory of Fluid Power& Mechatronic Systems;China Electronics Engineering Design Institute;China National Institute of Standardization;The present paper is aimed at bringing about a research status review on hydrogen safety use from the point of view of its leakage and diffusion,combustion and explosion,in addition to its compatibility with the metallic materials. As is known,the safety application of hydrogen is the key to its extended application in industry and transportation,in which the key problem is to prevent from its leakage and diffusion. For example,when the high-pressure hydrogen is released from the hydrogen storage tank or a transportation vehicle,it is likely to result in a hydrogen jet.However,if it is released into a confined space,it would be accumulated and then even lead to an explosion. But,if the transportation or transmission of hydrogen is done in a liquid form,it would be much safer for it can be made to stay in a liquid form on the ground for longer time than that in the gaseous form. Therefore,it would be possible and necessary for us to introduce our experimental and CFD simulation study with the hydrogen jets,with the hydrogen released in the confined space with the liquid hydrogen leakage,As a matter of fact,hydrogen combustion and explo-sion tends to lead to the temperature or pressure rise in the process of hydrogen combustion and explosion. Furthermore,our experiments and numerical simulation demonstrate that the accidental release of pressurized hydrogen is prone to spontaneous ignition,which has to undergo a strong flame acceleration and even deflagration-to-detonation transition. Besides,we have also made clear experimental and simulated studies of the effects of the hydrogen jet fires on its flame length and the heat flux. What is more,some papers have also studied the hydrogen compatibility with the metallic materials by using the testing results of its potential capacity all over the world,along with the high pressure bearing data it can withstand and the design criteria for the parts needed. From the aforementioned status in-situ,it would be possible to solve the following problems involved,such as promote the likely influential factors under consideration during the CFD numerical simulation of gas and liquid hydrogen release,in addition to the mechanism of the spontaneous ignition,the flame acceleration and deflagration-to-detonation transition,etc. Needless to say,it has also to pay more attention to the study of the designing methods for the bearing components to be used in the high pressure hydrogen application context.
Study on statistical analysis and emergency management of coal mine gas explosion accident
JING Guoxun;MU Lulu;To deeply investigate the current situation and characteristics of coal mine gas explosion accidents, this paper takes 63 gas explosion accidents from 2015 to 2021 as the research object, and uses the statistical analysis method combined with charts to analyze the accident level, area, month, time, and detonation fire. The number of accidents and fatalities is sorted and analyzed from five dimensions of source, and the improved Human Factor Analysis and Classification System(HFACS) model is used to construct five causal levels including external factors, organizational influence, unsafe supervision behavior, preconditions for unsafe behavior, and unsafe behavior. The causal factor model of coal mine gas explosion accidents and the causal relationship in different causal levels is analyzed with the help of the chi-square test and concession ratio analysis method. The results show that:(1) Shanxi, Shaanxi, and Heilongjiang account for 28.57% and 37.9% of the total number of gas explosion accidents in the country, and they are the key prevention and control provinces.(2) From October to December every year, the most accidents occur, causing the most injuries, and the accident frequency is the highest during the shift period and the 1st to 2nd hours after each shift.(3) Management factors, lack of organizational atmosphere, inadequate supervision, poor operator status, and operational errors are the five high-frequency causal factors affecting gas explosions and the high-frequency causal chain leading to gas explosions. Insufficient supervision by government supervision departments is the deepest causative factor, which leads to the lack of organizational atmosphere and loopholes in the organizational process of coal mining enterprises. As a result, it has adverse effects on coal miners and eventually leads to accidents. Therefore, to reduce and prevent the occurrence of gas explosion accidents, coal mining enterprises must pay attention to emergency management, and establish an emergency management index system in the whole life cycle to provide a certain reference for preventing gas explosions.
Research review on the trends and theoretical progress of safety science in recent years
WU Chao;WANG Bing;School of Resources and Safety Engineering,Safety & Security Theory Innovation and Promotion Center(STIPC),Central South University;The given paper is aimed at making a scientific and comprehensive insight review of the recent research trends and theoretical advances of the safety science mainly by using the speculation method,the typically characteristic literature retrospection and the comparative analysis approach.To identify the current and future research tendencies,hotspots,new starting prospectives in the novel research areas of the safety science,the focus of this paper has been put on the understanding of the latest developing trends of the safety theory.Therefore,first of all,a brief description has been given to the research hot spots,the research turns,the theoretical advances and the principal developing trends in the following 5 research directions,that is to say,the safety human factors,the safety natural science,the safety technology science,the safety social science and the safety systems science,respectively,in the worldwide scale.And,then,the description and statement of the paper has been provided to the theoretical research achievements of the Safety & Security Theory Innovation and Promotion Center(STIPC) of the Central South University of China in recent years,with the latest theoretical advances in this way illustrated in the next 9 aspects(namely,the new disciplines of safety science,the new safety theories,the methodology of safety science,the principles of safety science,the theoretical safety models,the comparative safety science,the similarity safety systematics,the safety culturology and the safety informatics) respectively from area to area.All in all,the research results have enabled us to demonstrate that,the hotspots and the key points in this way have undertaken a drastic shift,with the theoretic research achievements in the field closely being in combination with the demands of the safety science development and practice.Hence,in summary,the theoretic foundation of the safety science can be said to have been gradually becoming mature and growing in a healthy manner.
On the safety behaviors of the building workers from the perspective of the emotional intelligence and embodied recognition under the framework of the SOR theory
CHEN Wei-ke;LIU Guo-yi;The present paper is aimed to disclose the influential mechanism of the emotional intelligence and the embodied cognition on the safety behaviors within the framework of SOR theory construction workers.As is pointed out in the SOR theory,the outside environment can stimulate the individual psyche and lead to the change of the emotional and cognitive status of anyone or someone in a status in-situ.Based on the preliminary literature review,it would be possible for us to trace and examine objectively the emotional intelligence and the cognition of the building workers as intermediary variables we have taken from the safety climate,the non-contingent punishment and the ethical leadership as the externally exerted stimulus variables,and the safety behavior of the workers' own as the result variables.For further analyses,we have managed to analyze the data gained from the357 questionnaires from the on-4 ine workers engaged in the subway construction,the municipal construction and other construction industries of the similar trades via the software known as SPSS 22.0 and AMOS 22.0.The results of our survey and statistics show that the safety climate and the ethical leadership can produce a significant positive effect on the emotional intelligence and embodied cognition of the workers concerned,whereas the non-contingent punishment is potential of noticeable negative effects.In addition,the emotional intelligence and the embodied cognition on the part of such workers may also have a significant positive effect on their own safety behaviors,with the emotional intelligence and embodied cognition offered with a serious mediating effect in the SOR framework.For instance,the innovation of the authors of the given paper in its introduction of the SOR theory into the field of safety behavior research,which can not only help us to expand the research scope of SOR theory,but also confirm that it can also be used as a kind of effective tool to predict and forecast the safety behaviors of the said workers as well as to provide reference for the subsequent scholars in introducing the SOR theory into more research fields.And,secondly,from the perspective of the emotional intelligence and the embodied cognition,this paper has also made efforts in interpreting the safety behaviors of such workers to make up for their defects in the previous studies in neglecting the influential mechanism of the emotion and cognition on their behaviors,but also providing a reliable basis for the construction enterprises to formulate better safety management strategies in a more fruitful and purposeful way.
Research and application of PM2.5 concentration prediction model based on XGBoost-ARIMA method
LIU Yong-min;LUO Hao-yi;XIE Tie-qiang;Because of the nonlinear, unstable and fluctuating characteristics of the time series, a new XGBoost-ARIMA hybrid prediction model based on decomposition integration framework and correlation denoising is proposed in this paper. In this model, four de-noised multivariate factors(e.g., PM10 and SO2) are selected as input features and PM2.5 as the target features. The high-frequency and low-frequency data in the time series are reasonably distinguished and processed by constructing a hybrid model. The hybrid model can give full play to the prediction advantages of the two different models. XGBoost neural network shows excellent prediction performance for the complex high-frequency part, while ARIMA linear prediction model is more accurate for the relatively stable low-frequency part. The main flow of the hybrid model is as follows. Firstly, the model decomposes time series and multivariate factor series using the CEEMDAN algorithm and obtains several modal components with different frequency characteristics. Secondly, the Pearson correlation denoising method is used to process multivariate factor sequences to reduce the negative impact of noise factors on prediction performance. Thirdly, the fine-to-coarse algorithm reasonably distinguishes the high-frequency and low-frequency parts of the time series, and the XGBoost neural network is used to predict the high-frequency part, the ARIMA model is used to predict the low-frequency part. Finally, the prediction values of each part are summarized to obtain the final prediction result. The hybrid model proposed in this paper accurately predicts the average daily concentration of air pollutants, providing scientific data support for pollution control and policy-making. Example verification and comparison with the classical prediction model show that the mean absolute error of the new XGBoost-ARIMA hybrid prediction model is only 10.465 18, the root-mean-square-error is only 15.523 13, and the Hill inequality coefficient is as low as 0.085 89. Based on the root mean square error, the prediction performance of the hybrid prediction model improves by about 36.3% after correlation denoising, and compare with other classical prediction models, it has lower prediction error and higher prediction accuracy. In conclusion, the hybrid model proposed in this paper accurately predicts the average daily concentration of air pollutants, providing scientific data support for pollution control and policymaking.
Estimates of the exposed dermal surface area of Chinese in view of human health risk assessment
WANG Zhe,LIU Shao-qing,CHEN Xiao-min,LIN Chun-ye(State Key Joint Laboratory of Water Environment Simulation and Pollution Control,School of Environment,Beijing Normal University,Beijing 100875,China)The given paper is inclined to introduce its authors' research on the relation between the dermal exposure area and the health risk assessment as a result of dermal exposure,such of contaminated sites,which has been initiated in the environmental management departments concerned in our country.To begin with,we have borrowed and quoted some of such parameters originated in the US and Europe in this line.As is known,it is very common for human beings to expose their dermal surfaces to the outside in a variety of activities,such as washing, swimming,open-field working and/or dancing or special feats-performances,which may lead to different degrees of skin contamination.Since it is relatively difficult to make statistics and measurement of dermal surface area,the Chinese researchers used to adopt data on the dermal surface area of foreigners when they estimated the dermal exposure dose in the health risk assessment for us Chinese.This may result in the errors due to the differences in the body size between Chinese and the foreigners.The objective of this paper is to provide estimate in this way with the data of the body size of Chinese,including height and weight.For this purpose,we have collected the data of Chinese in this way and estimated the dermal surface area with the whole body and various body parts by using the models of Gehan and George,Haycock et al,and USEPA.Results of our estimates indicate that the average dermal areas of Chinese adult male and female were 1.69 m2 and 1.53 m2,respectively,which are lower than those of American counterparts by 13% and 10%.The average dermal areas of Chinese 2-12 old males and females were 0.84-0.91 m2 and 0.82-0.89 m2,respectively, while they are 1.48-1.57 m2 and 1.42-1.47 m2 for 12-20 old males and females.Therefore,the average dermal area of Chinese is generally lower than those of the Americans.In addition,the average dermal area of Chinese urban male and female is generally higher than those of Chinese in the countryside.It is such suggested that the parameter values of Chinese in their dermal surface exposure should be used in doing their health risk assessment in our country.