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1.
将山区地下开挖所引起的上覆岩土体的移动视为一模糊事件,应用模糊数学中的模糊测度理论,推导了相应的地表下沉及水平移动的理论计算公式,对煤矿开采所引起的地表移动进行了计算分析。通过工程实例计算分析表明,理论计算结果与工程实测资料吻合的很好。  相似文献   

2.
将模糊理论和神经网络相结合, 建立基于模糊神经系统的自然坡失稳预测模型--模糊神经网络(FANN)方法, 并针对我国湖北宜昌鄂西磷矿开采引起上部自然坡失稳的可能性进行了具体计算分析.  相似文献   

3.
根据深部矿体开采岩体移动变形的特点,建立了地面下沉值与影响因素间的模糊关系方程.确定出各指标间的模糊关系并对模糊关系方程进行了求解;然后通过模糊变换得出采区下沉的预测值.通过工程实例对比分析结果表明,理论分析结果与实测资料是一致的.  相似文献   

4.
巷道围岩变形是煤矿开采普遍存在的问题,巷道开挖过程中围岩会出现破裂现象.主要探讨模糊灰色系统的深部巷道围岩变形预测模型及应用,通过分析模糊数学理论、灰色理论,给出模糊灰色系统预测新陈代谢模型.  相似文献   

5.
通过建立某一地面下沉值与影响下沉的诸因素间的模糊关系方程,找出各指标间的模糊关系并进行求解;然后将要预计的厚覆盖岩层采区地面下沉值的各有关影响因素指标之实测值,通过实际求得的模糊关系作模糊变换,从而可得出采区下沉的最佳预测值。通过工程实例分析对比结果表明,理论分析结果与实测资料吻合。  相似文献   

6.
The paper outlines the application of a mathematical model of sustainability to an Environmental Impact Assessment (EIA) of two opencast iron ore mines in Iran. The model’s application to the EIA, which used the Folchi method, was undertaken for the purpose of indicating the potential level and nature of sustainability (if appropriate) of the two mines.The results indicated that both Chogart and Gol-e-Gohar iron ore mine were deemed to be potentially unsustainable. The results suggests the delicate balance and failure of achieving some form of sustainability in regards to mining in Iran, due to the impacts it has upon the local environment and community affected. The paper concludes as to the potential significance of the model’s application in the attainment of the goal of sustainable mining.  相似文献   

7.
Motivated by an underground mining operation at Kiruna, Sweden, we formulate a mixed integer program to schedule iron ore production over multiple time periods. Our optimization model determines an operationally feasible ore extraction sequence that minimizes deviations from planned production quantities. The number of binary decision variables in our model is large enough that directly solving the full, detailed problem for a three year time horizon requires hours, or even days. We therefore design a heuristic based on solving a smaller, more tractable, model in which we aggregate time periods, and then solving the original model using information gained from the aggregated model. We compute a bound on the worst case performance of this heuristic and demonstrate empirically that this procedure produces good quality solutions while substantially reducing computation time for problem instances from the Kiruna mine.  相似文献   

8.
结构的失效可能度及模糊概率计算方法   总被引:2,自引:1,他引:1  
依据模糊可能性理论,系统地建立含模糊变量时结构的可靠性计算模型。旨在解决模糊结构、模糊-随机结构和模糊状态假设下结构的可靠性计算问题。所建模型可给出模糊结构失效的可能度和模糊-随机结构失效概率的可能性分布。研究表明:对同时含模糊变量和随机变量的混合可靠性计算问题,把失效概率(或可靠度)作为模糊变量,能更客观地反映系统的安全状况。算例分析说明了文中方法的合理性和有效性。  相似文献   

9.
高陡山区岩体移动分析的Fuzzy数学模型   总被引:1,自引:0,他引:1  
本文利用 Fuzzy数学理论 ,针对高陡山区地下房柱法采矿所引起的岩体移动变形问题 ,建立了具体的数学模型和预测分析方法 .通过对工程实例的计算分析 ,表明本文所建立的数学模型和分析方法适用于工程实际  相似文献   

10.
Underground mine production scheduling possesses mathematical structure similar to and yields many of the same challenges as general scheduling problems. That is, binary variables represent the time at which various activities are scheduled. Typical objectives seek to minimize costs or some measure of production time, or to maximize net present value; two principal types of constraints exist: (i) resource constraints and (ii) precedence constraints. In our setting, we maximize “discounted metal production” for the remaining life of an underground lead and zinc mine that uses three different underground methods to extract the ore. Resource constraints limit the grade, tonnage, and backfill paste (used for structural stability) in each time period, while precedence constraints enforce the sequence in which extraction (and backfill) is performed in accordance with the underground mining methods used. We tailor exact and heuristic approaches to reduce model size, and develop an optimization-based decomposition heuristic; both of these methods transform a computationally intractable problem to one for which we obtain solutions in seconds, or, at most, hours for problem instances based on data sets from the Lisheen mine near Thurles, Ireland.  相似文献   

11.
The optimality of a fuzzy logic alternative to the usual treatment of uncertainties in a scheduling system using probability theory is examined formally. Fuzzy scheduling techniques proposed in the literature either fuzzify directly the existing scheduling rules, or solve mathematical programming problems to determine the optimal schedules. In the former method, the fuzzy optimality for the optimal scheduling rules is usually not justified but still assumed. In this paper, the necessary conditions for fuzzy optimality are defined, and fuzzy counterparts of some of the well-known scheduling rules such as shortest processing time (SPT) and earliest due date (EDD) are developed.  相似文献   

12.
This paper addresses the problem of defining and analyzing relations between finite sets which are involved in personnel management.Personnel management criteria are imprecise due to the complex nature of the requirements and the difficulties to deal with personnel characteristics. Fuzzy set theory seems to be an efficient tool for considering these imprecisions. According to this idea the relations involved in personnel management can be seen as fuzzy relations.R.H. Atkin has formulated the abstract simplicial complex, achieving a structure which permits a deep knowledge of non fuzzy relations. In a sense this structure can be interpreted as a geometrical multidimensional one. Our purpose is to set up a multidimensional structure associated with the fuzzy relations which appear in personnel management.By means of an analysis of the above structure it is possible to study problems concerning the recruitment selection and promotion of personnel.  相似文献   

13.
One of the main tasks in exploitation of ore-body is to select a suitable mining method. In mining method selection (MMS) problems, a decision procedure has to choose the best exploitation method that satisfies the evaluation criteria. It is generally hard to find a mining method that meets all the criteria simultaneously, therefore a good compromise solution is preferred as the final selection. Furthermore, the MMS problem is an inherently uncertain activity. To deal with the uncertainty, this paper presents an hybrid decision support system based on the fuzzy multi attribute decision making, named the fuzzy mining method selection with interrelation criteria (FMMSIC). FMMSIC models the relative weights of criteria by combining the fuzzy analytic network process and fuzzy entropy, and discusses using these hybrid techniques to determine the overall weights. Subsequently, the technique for order preference by similarity to an ideal solution method was modified by various normalization norms according to the MMS problem condition. Finally, to illustrate how the FMMSIC is used for the MMS problems, an empirical study of a real case is conducted. It shows by means of an application that the FMMSIC is well suited as a decision support system for the MMS.  相似文献   

14.
This paper is concerned with the numerical treatment of inverse heat conduction problems. In particular, we combine recent results on the regularization of ill-posed problems by iterated soft shrinkage with adaptive wavelet algorithms for the forward problem. The analysis is applied to an inverse parabolic problem that stems from the industrial process of melting iron ore in a steel furnace. Some numerical experiments that confirm the applicability of our approach are presented.  相似文献   

15.
针对金属矿山企业的单位开采与运输成本大、优化求解结果偏差大问题, 首先, 依据金属矿山企业编制开采计划的基本原则, 以矿石开采与运输成本最小化为优化目标, 利用整数规划方法, 构建了金属矿山企业生产计划数学模型, 其次, 为了精准快速求解金属矿山企业生产计划模型, 提出了改进的量子粒子群优化算法, 采用进化速度和聚集度因子对算法中的惯性权重进行动态调整, 并设计了双层可行域搜索策略, 提高了算法的局部和全局搜索能力。最后, 以某大型金属矿山企业采运生产作业为案例, 通过与矿山实际生产指标、非线性规划结果以及粒子群优化结果进行比较分析。结果表明:在相同经济指标和参数环境下, 本文算法优于其它两种优化方法, 且每吨矿石的开采和运输成本减少了0.05元左右, 降低了金属矿山企业的开采运输成本, 提高了企业的整体经济效益。  相似文献   

16.
This paper considers multiobjective integer programming problems where each coefficient of the objective functions is expressed by a random fuzzy variable. A new decision making model is proposed by incorporating the concept of probability maximization into a possibilistic programming model. For solving transformed deterministic problems, genetic algorithms with double strings for nonlinear integer programming problems are introduced. An interactive fuzzy satisficing method is presented for deriving a satisficing solution to a decision maker by updating the reference probability levels. An illustrative numerical example is provided to clarify the proposed method.  相似文献   

17.
Relative accuracy of numerical quadrature rules when applied to the simulation of underground petroleum reservoirs by means of the finite element method is investigated. Fluid flow within the reservoir is calculated via the finite element method and the resulting deformation by the nucleus of strain technique. By analysing a simple problem it was found that the solution method was susceptible to changes in numerical quadrature for reservoirs that were positioned near the ground surface and that care is required when solving such problems due to the singularities occurring in the integrands which appear in the nucleus of strain approach.  相似文献   

18.
Complex underground constructions in urban areas require strict predictions for ground movements and liner deformation induced by shield-driven tunneling, in which the complex interaction mechanics between ground and liner play a substantial role. Previous studies, however, provided little information on the ground-liner interaction and less attention to the effects of groundwater and compressed air during the shield operation. This paper presents a closed-form analytical solution for predicting long- and short-term ground deformation and liner internal forces induced by tunneling in saturated soils in which shield excavation effects with and without air pressure are both considered. The oval-shaped convergence deformation pattern is incorporated as the boundary condition of displacements around the tunnel section. This paper also investigates the difference between uniform radial and oval-shaped convergence deformation patterns on the ground and tunnel responses. Generally, the predicted ground movements by the oval-shaped deformation pattern aligns well with measured data of actual tunnels with and without considering the shield air pressure. It is comparatively observed that the shield excavation under air pressure obtains larger ground deformation than the non-pressure condition, and the long-term ground settlements induced by tunneling in saturated soils are confidently larger than the short-term. Moreover, the effects of sensitive parameters, including the shield air pressure, the long- and short-term effects on the tunneling-induced ground movements are assessed based on the oval-shaped deformation pattern. Furthermore, parametric analyses are conducted to measure the influences of concerned tunneling coefficients on the liner displacements and internal forces, namely, soil Young's modulus, soil unit weight, coefficient of lateral soil pressure, tunnel radius, tunnel buried depth and gap parameter. In summary, the analytical approach proposed in this research provides an effective insight into the ground-liner interaction mechanics related with the shield air pressure, which can serve as an alternative approach in the preliminary design for conservatively estimating the excavation influences caused by tunneling in saturated soils.  相似文献   

19.
刘书庆  王怡萍 《运筹与管理》2021,30(11):176-182
为有效解决因产品质量危机事件发生原因揭示不准确而导致应对措施选择与实施不当问题,根据产品质量危机影响因素发掘结果,提取出了产品质量危机事件可能原因,采用故障树法构建了质量危机事件潜在原因关系模型;将故障树法和贝叶斯网络相结合,基于专家调查与模糊集理论,推理出底层原因先验概率算法,并将其先验概率输入贝叶斯网络模型,获得底层原因后验概率及关键重要度,将后验概率及关键重要度共同作为质量危机事件关键原因诊断依据,构建了质量危机事件原因挖掘模型;通过实际案例验证了关键原因挖掘结果的准确性,为企业挖掘质量危机事件发生原因提供了理论依据。  相似文献   

20.
In this paper, a new method for comparing fuzzy numbers based on a fuzzy probabilistic preference relation is introduced. The ranking order of fuzzy numbers with the weighted confidence level is derived from the pairwise comparison matrix based on 0.5-transitivity of the fuzzy probabilistic preference relation. The main difference between the proposed method and existing ones is that the comparison result between two fuzzy numbers is expressed as a fuzzy set instead of a crisp one. As such, the ranking order of n fuzzy numbers provides more information on the uncertainty level of the comparison. Illustrated by comparative examples, the proposed method overcomes certain unreasonable (due to the violation of the inequality properties) and indiscriminative problems exhibited by some existing methods. More importantly, the proposed method is able to provide decision makers with the probability of making errors when a crisp ranking order is obtained. The proposed method is also able to provide a probability-based explanation for conflicts among the comparison results provided by some existing methods using a proper ranking order, which ensures that ties of alternatives can be broken.  相似文献   

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