scholarly journals Comprehensive Risk Evaluation in the Long-Term Operation of Urban Subway Based on Multiple Indices

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Baoping Zou ◽  
Di Sun ◽  
Jundong Mu ◽  
Zhipeng Xu

The reasonable risk evaluation in the long-term operation of urban subway systems is of importance to the public safety and maintenance work of the subway. At present, the risk assessment always depends on a specified single factor which might result in a biased risk result. In order to take more influential factors into account, the multiple indices system is developed for the total risk evaluation in this work. The proposed multiple indices system is established on the basis of the logical structure of the analytic hierarchy process (AHP). It is based on the 7 selected factors in which the value of each factor is defined by its risk level and the corresponding weight is determined by the AHP calculation. The result obtained from the case study showed that the total risk levelgot from the proposed method is more reasonable than the traditional single index-based methods.

2014 ◽  
Vol 556-562 ◽  
pp. 6665-6668
Author(s):  
Xiao Jun Lu ◽  
Kai Wen Zeng ◽  
Shi Wu Liao ◽  
Jin Yu Wen ◽  
En Lu ◽  
...  

A set of blackout risk assessment indexes is established according to Electricity Accident (Incident) Investigation Procedures of China Southern Power Grid (CSPG) (pilot) and Guide on Operational Risk Evaluation of CSPG, which can calculate risk values of electricity accidents (incidents). The calculation process is discussed in detail. Based on the proposed indexes and OPA blackout model, a blackout risk assessment method for power system is put forward, with which blackout risk for all 500kV buses in Guangdong Power Grid are evaluated. Weak areas in power system are identified and their inducements are analyzed. The identification results accord with actual system long-term operation experience, which verifies the correctness of the indexes and method.


2012 ◽  
Vol 256-259 ◽  
pp. 2790-2793 ◽  
Author(s):  
Dan Zhang ◽  
Xiang Rui Yang ◽  
Xiao Biao Fan

The Ship-Bridge collision accident risk evaluation model based on the analytic hierarchy process (AHP) was established and the weights of factors were confirmed. Qualitative and quantitative assessments of the Vessel-Bridge collision accident risk level were accomplished. The application results show that the possibility of Ship-Bridge collision accident could be evaluated by the security risk evaluation model based on the AHP. It can provide decision-making suggestions for the sitting of the new bridge and optimal evaluation for bridge type scheme.


2020 ◽  
Author(s):  
Sheng-Shan Chen ◽  
Han-Xiang Wang ◽  
Hao Jiang ◽  
Ya-Nan Liu ◽  
Yan-Xin Liu ◽  
...  

Abstract Casing corrosion during CO2 injection or storage results in significant economic loss and increased production risks. Therefore, in this paper, a corroded casing risk assessment model based on analytic hierarchy process and fuzzy comprehensive evaluation is established to identify potential risks in time. First, the corrosion rate and residual strength characteristics are analyzed through corrosion tests and numerical simulations, respectively, to determine the risk factors that may lead to an accident. Then, an index system for corroded casing risk evaluation is established based on six important factors: temperature, CO2 partial pressure, flow velocity, corrosion radius, corrosion depth and wellhead pressure. Subsequently, the index weights are calculated via the analytic hierarchy process. Finally, the risk level of corroded casing is obtained via the fuzzy comprehensive evaluation. The corroded casing risk assessment model has been verified by a case well, which shows that the model is valuable and feasible. It provides an effective decision-making method for the risk evaluation of corroded casing in CO2 injection well, which is conductive to improve the wellbore operation efficiency.


2017 ◽  
Vol 1 (21) ◽  
pp. 65-73
Author(s):  
Monika Gwoździk

The paper presents results of studies on the crystallite sizes of oxide layer formed during a long-term operation on 10CrMo9-10 steel at an elevated temperature (T = 545° C, t = 200,000 h). This value was determined by a method based on analysis of the diffraction line profile, according to a Scherrer formula. The oxide layer was studied on a surface and a cross-section at the outer and inner site on the pipe outlet, at the fire and counter-fire wall of the tube. X-ray studies were carried out on the surface of a tube, then the layer’s surface was polished and the diffraction measurements repeated to reveal differences in the originated oxides layer.


Author(s):  
Юлия Владимировна Татаркова ◽  
Татьяна Николаевна Петрова ◽  
Олег Валериевич Судаков ◽  
Александр Юрьевич Гончаров ◽  
Ольга Николаевна Крюкова

В настоящей статье представлен обзор основных решений, доступных сегодня для формирования как краткосрочных, так и долгосрочных проекций заболеваемости болезней глаза и его придаточного аппарата в студенческой среде. С другой стороны, существует ряд проблем, связанных с многообразием факторов, влияющих на заболеваемость, статистической необоснованностью и противоречивостью имеющихся результатов анализа данных. Представлены результаты математического моделирования зависимости показателя заболеваемости от наиболее влиятельных факторов образовательной и социальной среды. Перечислены важнейшие направления разработки математических моделей распространения заболеваемости. С помощью разработанного программного комплекса проведена серия вычислительных экспериментов по оценке и прогнозированию заболеваемости обучающихся в вузах разного профиля. Показана эффективность применения методики многовариантного моделирования и прогнозирования, указаны их ограничения и возможности практического применения. По расположению обобщенной области благоприятного прогноза в факторном пространстве можно определить время воздействия неблагоприятных для зрения факторов, которое должно составлять не более 10 ... 11 часов в сутки, количество профилактических мероприятий должно составлять не менее 3 ... 4. При этом риск развития миопии составит не более 0,4, вероятность усталости глаз за компьютером составит не более 0,4, вероятность дискомфорта глаз на занятиях составит не более 0,15. Исходя из характера прогноза, определяется длительность диспансерного наблюдения, а также потребность профилактических мероприятий по устранению или ослаблению действия неблагоприятно влияющих социально-гигиенических и медико-биологических факторов конкретного больного. Использование прогностической матрицы в практическом здравоохранении позволяет существенно улучшить работу по профилактике офтальмологической заболеваемости и является одним из эффективных мероприятий диспансеризации студенческой молодежи, так как дает возможность выделить из числа обучающихся группу с высоким риском неблагоприятного исхода заболевания This article provides an overview of the main solutions available today for the formation of both short-term and long-term projections of the incidence of eye diseases and its adnexa in the student environment. On the other hand, there are a number of problems associated with a variety of factors affecting the incidence, statistical unreasonability and inconsistency of the available data analysis results. The results of mathematical modeling of the dependence of the incidence rate on the most influential factors of the educational and social environment are presented. The most important areas of developing mathematical models for the spread of morbidity are listed. With the help of the developed software package, a series of computational experiments was carried out to assess and predict the incidence of students in universities of various profiles. The effectiveness of the application of multivariate modeling and forecasting methods is shown, their limitations and practical application possibilities are indicated. By the location of the generalized region of favorable prognosis in the factor space, it is possible to determine the exposure time of factors unfavorable for vision, which should be no more than 10 ... 11 hours a day, the number of preventive measures should be at least 3 ... 4. At the same time, the risk of development myopia will be no more than 0.4, the probability of eye fatigue at the computer will be no more than 0.4, the likelihood of eye discomfort in the classroom will be no more than 0.15. Based on the nature of the forecast, the duration of the follow-up observation is determined, as well as the need for preventive measures to eliminate or weaken the action of adverse social, hygienic and biomedical factors of a particular patient. The use of the prognostic matrix in practical health care can significantly improve the work on the prevention of ophthalmic morbidity and is one of the effective medical examinations for students, since it makes it possible to distinguish among the students a group with a high risk of an unfavorable outcome of the disease


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