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Study on emergency decision support system of urban community safety based on GIS
XU Zhi-sheng, FENG Kai, XU Liang, FENG Chun-ying( Disaster Prevention Science and Safety Technology Institute, Central South University, Changsha 410075, China)The paper aims to introduce the process of developing the emergency decision support system of urban community safety. As is known, the decisions towards unexpected accidents in the city mainly traditionally rely on the experience and ability of the decision-makers, which inevitably involves too many subjective factors and unavoidable consequences in the process of emergency response. This accounts for the geographic information systems integration with the decision support system to be adopted for the development of the urban community safety emergency decision support systems. The present author intends to illustrate the goals, structural framework and functions of the systems. In addition, we also suggest the necessary technological scheme to build a high-speed and highly efficient spatial database. Based on the visualization and digitalization of infrastructure and disaster information, the decision support system incorporated with the disaster information management, disaster prevention plan and emergency decision pattern has been established, so as to provide the decision-makers with the power to choose schemes to manage and direct the actions to be taken more efficiently in the process of immediate and long term recovery.
Carbon emission reduction between government and heavily polluting enterprises under carbon trading mechanism based on evolutionary game analysis
YANG Xia;HE Gang;WU Chuanliang;WANG Xiaodong;Based on the willingness of the public and enterprise, this paper constructed a government and heavily polluting enterprises evolutionary game theory model for exploring factors influencing carbon emission reduction of heavily polluting enterprises under the carbon trading mechanism and studying the game interaction mechanism between government and heavy polluting enterprises. In this process, we introduced three government low-carbon regulatory means, namely, carbon trading, carbon subsidies, and carbon penalties. Under this condition, this paper first determined the stabilization strategy of the system under different scenarios by calculating the replication dynamic equations and Jacobi matrices between them. Then, we selected the relevant data from the national carbon emission trading pilot areas for numerical simulation by using MATLAB software. Results show that first of all the carbon reduction efficiency of heavily polluting enterprises is improved by combining governmental low-carbon regulatory instruments. Among them, the combination of carbon penalties, carbon subsidies, and carbon trading is the optimal regulatory strategy, followed by the combination of carbon penalties and carbon subsidies. And heavily polluting enterprises will quickly tend to negative carbon emission reduction without considering any low carbon regulation means and relying only on market regulation, which cannot promote the realization of carbon emission reduction goals. In addition, as an important influencing factor in the carbon trading mechanism, carbon trading revenue can effectively suppress the negative effect of cost factors and realize the purpose of the carbon trading mechanism to promote the active participation of both government and heavily polluting enterprises in carbon emission reduction. Moreover, it is found that carbon trading revenue is easily influenced by the price and carbon quota linkage, and breaking a certain threshold which has a positive effect on both sides of the game, but there is a fluctuation effect. Last but not least, the evolutionary game system of carbon emission reduction between them is affected by multiple factors, mainly composed of the initial strategy ratio of both parties, cost-benefit, public willingness, enterprise willingness, and carbon trading market, which together drive the evolution of the system. Besides, it is important to note that the factors of public-to-enterprise, public-to-government, and enterprise-to-government willingness constraints cannot be ignored, and they can effectively inhibit negative regulation and negative carbon reduction. Among them, in particular, the role of enterprise-to-government willingness constraint is significant, and it can effectively promote both sides to adopt positive behaviors.
Status quo and trend of urban soil contamination research
JIANG Hai-yan~1, LIU Min~1, HUANG Shen-fa~2, SHEN Gen-xiang~2, WU Jian~2(1 Department of Geography, Open Laboratory of Geo-information Science of Ministry of Education, East China Normal University, Shanghai 200062, China; 2 Shanghai Academy of Environmental Sciences, Shanghai 200233,China)The present paper aims to give a general survey of the status quo and trends of the urban soil contamination research in China in recent years. As is known, urban soil is one of the essential constituent parts of research that has had an important effect on the urban sustainable development. So the problems of urban soil contaminations have been paid more and more attention. During the last decade, the studies concerning the heavy metal pollution, organic pollution and biogenic pollution of surface soils in the urban areas, have been conducted around the world. However, large urban areas are seriously contaminated with concentrations of pollutants. These research results could systemically provide important scientific proofs of urban ecological environment quality. Since soil contaminations in urban environment are attached with more and more concern among the international scientific communities, the recent trends and emphases in research have been put on such issues as the conception and kinds of urban soil contaminations, the research about the combined pollution of urban soil, thirdly, remediation technologies, especially bioremediation technologies, the last but not the least environmental management policy.
Testing and determination of the olfactory thresholds of the 40 kinds of typical malodorous substances
WANG Gen;ZHAI Zeng-xiu;GENG Jing;HAN Meng;LU Fu-lei;The given article is inclined to introduce the results of its testing and determination of the olfactory thresholds of 40 kinds of typical malodorous substances.For the said purpose,we have first of all selected 40 kinds of typical malodorous substances while searching through the domestic and foreign literature with the analysis results of the odor samples commonly used in all the industrial branches.The said substances belong to 5 kinds of typical malodorous substances,such as the sulfur compounds,nitrogen compounds,benzene series,olefins and oxygenated organic compounds.According to the air quality-testing and determination of the odor-triangle odor bag method(GB/T 14675—93),we have worked out the olfactory thresholds of the aforementioned substances with a certain concentration gradient of the standard gas.As a result of our testing and determination,we have established a database of the typical malodorous substances with the said method.In addition,we have also managed to classify the olfactory threshold range of the said 40 substances into three ranks:higher thresholds(10-1×10-6-10×10-6),middle thresholds(10-3×10-6-10-2×10-6),the lower thresholds(10-5×10-6-10-4×10-6).In so doing,we have made a careful depiction of the odor quality of the substrates respectively and a preliminary analysis of the relationship between the molecular structure and the threshold data.As a result,we have found that there exists great difference in the odor characteristics for the different substances.For example,benzene serial compounds tend to produce a smell of aroma;the sulfur compounds enjoy the priority to give off a rotten egg smell;the same is true to the hydrogen sulfide.On the other hand,nitrogen compounds tend to produce a stimulating odor as ammonia.As to the aldehydes and esters,they prefer mainly to deliver flower or fruit fragrance,while acids are endowed primarily with a smell of sweat.Thus,the analysis and the application of olfactory thresholds in the stench pollution control,helps us to know that it is of great significance and interest to choose and remove the malodor substance effectively as well as to remove,prevent and control the stench pollution in hoping to improve the ecological environment.
Comprehensive risk assessment method of working at height based on improved Bayesian network
ZHAI Yue;DU Jing;GAO Ja-yan;To conduct a comprehensive risk analysis of high-altitude construction work more reasonably, this research proposes a safety assessment method based on Bayesian theory. In view of working conditions at heights, based on case analysis, literature research and on-site monitoring, risk factors are identified from the four aspects of human, material, environment and management, and a preliminary establishment of a safety evaluation index system for working at heights, and qualitative and quantitative evaluation standards and indicators are proposed. The basis for judging the level of risk factors provides a theoretical basis for the combination of qualitative and quantitative risk assessment. Based on the basic Bayesian theory, comprehensive use of difference degree ranking technology, extension model theory based on tomographic analysis(AHP), and dynamic weighting method, quantitative and qualitative data are combined and analyzed, and the dynamic index weight is realized renew. Finally, the combined weighting of the Bayesian model is determined. By changing the parameter “weighted distance”, the risk assessment results are more accurate and reasonable. By introducing the parameter “score equilibrium”, the gap between the probability values of the project at different risk levels and the gap between the probability values of the risk levels at different time points is widened, and the problem of inaccurate risk evaluation caused by close or equal probabilities is solved. Taking a building construction high-altitude operation project in Northwest China as an example, the intelligent safety monitoring equipment is developed to monitor the construction site, and the sensitivity analysis of the monitoring indicators that characterize the weather and physical conditions is carried out to obtain the sensitive factors in the high-altitude operation project. The results show that the key factors considered during construction at heights in winter in Northwest China are human heart rate, environmental humidity, noise, and PM2.5. Compared with the traditional method, this method can more accurately obtain the risk factors and the changing trend of construction risk and improve the problem of risk classification in a critical state. By obtaining the dynamic update of the combined weights of the Bayesian model, the index weights are more accurate and reasonable. The improved method can not only calculate the risk value of a certain period but also compare the safety risks of different periods of the project, which solves the problem of inaccurate risk assessment. The research results are important for solving the safety production problems of high-altitude operations.
Study on construction risk factors based on ISM and MICMAC
LI Ming-zhu;WANG Wen-dong;ZHANG Zhi-chao;It is especially important to accurately identify the main factors that influence construction safety, analyze the working mechanism, and construct the system of influential factors in construction risk management. Firstly, this study screened out 14 main factors of construction risk and formed 6 levels of risk, like personnel factor, mechanical factor, environmental factor, management factor, and other factors based on analysis of direct and indirect causes of construction safety accidents. Secondly, this study also calculated the adjacency matrix and reachable matrix of construction safety risk factors and judged the relationship of the matrixes by use of MATLAB software. The study constructed an Interpretation Structure Model(ISM) and a hierarchical structure diagram to determine the hierarchical relationship among the influential factors and classified the influential factors according to the dependence and driving force using Matrix Impacts Cross-reference Multiplication Applied to a Classification(MICMAC). Finally, the study calculated a case using the established ISM model and MICMAC method to verify the feasibility of the application. The results show that the influential factors of the construction safety risk are divided into 6 levels(Li, i = 1-6) and the importance increases accordingly. Based on the dependence and driving force, the influential factors were divided into three categories: autonomous cluster, independent cluster, and dependent cluster. Human behavior and the safe state of facilities and equipment were at the level of L1 in the ISM model, with the low driving force and strong dependence, belonging to a dependent cluster. Management system, safety inspection, supervision, and management departments were at the level of L6 in the ISM model, with a potent driving force and low dependence, belonging to an independent cluster. It is concluded that human behavior and the safe state of facilities and equipment are important causes of construction safety risks. Management systems, safety inspection, supervision, and management departments are the most fundamental factors that constitute the risk of construction and need more attention. The model and method are feasible and effective to excavate risk factors, construction risk factor systems, analyze and determine the level, driving force, and dependence of risk factors, formulate corresponding risk management countermeasures and prevent and dissolve construction risks.
Research on influencing factors of serious traffic accidents on freeway based on improved DEMATEL-ISM
DAI Xue-zhen;HU Chuan-xi;To analyze the influencing factors of major and extraordinarily serious traffic accidents on freeways, this study proposed an improved Decision Experimentation and Evaluation Laboratory-Interpreted Structural Modeling Method(DEMATEL-ISM). First, the influencing factors were initially classified according to the three concepts of driving force, dependence, and coexistence of driving force and dependence. The interactions of the influencing factors were described using orientation diagrams, and the direct influence matrix was solved using frequency weights. Secondly, the DEMATEL-ISM model was used to solve the influence degree, influenced degree, centrality degree, cause degree, and hierarchical framework diagram of each influencing factor. Finally, the calculated results of DEMATEL-ISM were analyzed and compared with the unimproved DEMATEL method and K-means clustering model. A total of 226 major and extraordinarily serious traffic accidents in Shaanxi Province from 2018 to 2019 were set as calculated and analyzed examples. The results of the study showed that nighttime, heavy trucks and trailers, small and medium-sized trucks, straight roads, speeding, and fatigued driving are the main influencing factors of major and extraordinarily serious traffic accidents on freeways. Night, straight road, rain, and poor road surface are the causative factors, and speeding and fatigued driving are the resultant factors. Low-speed driving, tunnels, and snowy days have little effect on major and extraordinarily serious traffic accidents. Compared with the traditional DEMATEL method, although the centrality of their solutions is similar, the improved DEMATEL method can effectively distinguish the degree of influence and the degree of the role of the influencing factors, making the solution results more accurate and identifying the cause degree more specific. The reliability and superiority of the improved DEMATEL-ISM model in the analysis of influencing factors of highway heavy traffic accidents are verified by analyzing the clustering results of samples through the K-means clustering model.
On the reliability of automatic fire detection and alarm systems
XU Xiao-hu1,ZHENG Xin1,ZHAO Hai-rong2,XU Kai-li1,ZHANG Pei-hong1,KANG Yong1(1 School of Resource & Civil Engineering,Northeastern University,Shenyang 110004,China;2 Shenyang Fire Research Institution,Ministry of Public Security,Shenyang 110034,China)The present paper is focused on the research of the reliability of automatic fire detection and alarm systems in hoping to overcome the problem of false alarming,which,as a matter of fact,has still been puzzling event for the experts in this area.So far as we know,the automatic fire detection and alarm system is made up of four parts: the fire detector,the fire alarm controller,the fire-reducing device and the fire-extinguishing device.Therefore,our analysis focus has to be put on the above said four aspects so as to make clear what are the main factors that may account for the failure of the system.It is for this purpose we have proposed the problem of probability of the false alarm and omitted alarm concept,which may involve both the fire detection system and the fire alarm controller.To make it clear,we have analyzed the failure states the whole system may involve in the process of actual application.The results of our study have shown that direct reasons in such failures or troubles,including various problems of the detector design,the detection selection and installation as well as those of the controller and controlling software should account for the fundamental direct factors of the dysfunction of the system.And among the above mentioned factors that might be responsible for the failure,the primary reasons should also include three categories,that is to say,the hardware failure,the system failure and improper management.Therefore,essential measures should be taken to improve the reliability of the automatic fire detection and alarm system in design,hardware and software product quality,the selection and installation and maintenance.And,finally,we have reviewed and reformed the automatic fire detection and alarm system reliability calculation model based on the system safety and reliability theory,including the four indexes of the power supply system,the trigger device,the alarm control device and the alarming device,which can serve as a theoretical basis and guide for inspecting the overall reliability of such systems.
On the influence of DNA extraction from activated sludge for denaturing gradient gel electrophoresis on microbial diversity analysis
LI Peng1, BI Xue-jun1,2, RU Shao-guo1(1 Marine Life College, Ocean University of China, Qingdao 266003, Shandong, China; 2 School of Environmental and Municipal Engineering, Qingdao Technological University, Qingdao 266033, Shandong, China)This paper aims to report the authors' research results on the influence of different methods of direct DNA extraction and purification from the activated sludge on the microbial diversity analysis by polymerasing the chain reaction to denaturing the gradient gel electrophoresis (PCR-DGGE). In doing so, we have adopted six different procedures to physically disrupt the cells so as to obtain the total sum of DNA: sonication. Then, two other methods were used for DNA extraction by using the microwave-based method and the grinding-freezing-thawing + the bead beats and lysozyme + SDS method. Afterwards, the PCR amplification of the extracted microbial 16S rRNA gene fragments (V3 region) was conducted by using the universal primers GC-341f and 518r. And, next, an analysis of sequence diversity in all extracts was made by using the polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE). DGGE on a DGGE analyzer with 8% (m/V) acrylamide (37.5∶1 acrylamide-bisacrylamide) gel loaded under a 30% to 60% linear gradient of denaturant. The results show that the community patterns revealed by DGGE were noticeably influenced by the different DNA extraction methods. However, no much influence has been found by the purification (solution purification and agarose gel purification) and PCR amplification (direct PCR and nested-PCR), thus demonstrating the importance of the DNA extraction protocol on the evaluating activated sludge microbial diversity. The above results gained from our experiments prove that the method of SDS-based DNA extraction (Zhou method) is the most efficient one, which may have resulted in the largest number of DNA bands, that is, the highest number of bacterial species. As to the quantities of DNA gained from SDS-based DNA extraction, there were only (14.85±2.5) μg·g-1 (wet wt) of activated sludge with OD260/OD280 purity ratios of 1.8±0.23. Therefore, it can be suggested that the DNA extractions from the activated sludge should be highly appreciated not only in terms of quantity and purity, but also in terms of the sequence diversity present. Furthermore, it can be concluded that the SDS-based DNA extraction protocol from activated sludge (Zhou method) is expected to be adopted as a rapid and reliable means for further microbial molecular ecological study.
Statistics and analysis of coal mine gas accidents in China from 2015 to 2019
JING Guo-xun;LIU Meng-xia;This paper is to make research on the law of coal-gas mining accidents in China during the period from 2015 to 2019 by applying the statistical analysis method and analyzing the dimensions of accident types, regions, months, and inducement. For our research goals, we focus on analyzing the general laws of coal mine gas accidents in China and fundamentally analyze the general laws and characteristics of gas accidents. The results show that:(1) With the increase of mining depth, geological conditions are more complex and changeable and gas accidents increase year by year.(2) In these gas accidents, the main accident type is gas explosion and it often occurs in the process of gas outburst and mine blasting; The consequences of gas explosion include a large number of casualties and economic losses.(3) Gas accidents are more likely to occur in 10:00-12:00 and 18:00-20:00, and the two hours before and after the shift is the period for key prevention.(4) In terms of months, coal mines are most prone to gas accidents in May, October, and December; The highest number of gas accidents occurred in October and the highest number of deaths from gas accidents occurred in December.(5) The areas of Guizhou, Shanxi, Sichuan, and Hunan Provinces have high occurrence frequencies of gas accidents, among which Guizhou Province has the most gas accidents.(6)The main factor leading to coal mine gas accidents is illegal operation. To reduce the occurrence of coal mine gas accidents, coal mine enterprises must pay attention to the cultivation of workers' safety consciousness, strengthening the management of production technology, strengthening the safety inspection of ventilation facilities, strictly punishing violations in the mining process, increasing the intensity of punishment, strengthening safety management and safety supervision; strengthening safety supervision by relevant administrative departments.