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1.
it is necessary to balance the failure risk and the maintenance expensive. A methodology for reliability based maintenance optimization of steel bridge welded joints subjected to fatigue is proposed considering linear elastic fracture mechanics (LEFM), the structure reliability, life cycle cost method and maintenance strategies. The maintenance cost is divided into inspection, repair and failure sections according to the whole life cycle cost methodology. And the maintenance strategy is transformed to the minimum expected lifetime costs with a constraint of the minimum acceptable reliability index. An case concerning to a transverse stiffener of bottom flange welded joint of Qingcaobei bridge is studied with a certain number of simplifications. Some sensitivity analysis is provided. Among all the parameters, discount rate is the most remarkable. 相似文献
2.
This paper discusses the influenced manner of reliability on bidding, and establishes the direct functional relationship among reliability, generation cost and electricity price in different risk of power generation. In this function model, the generation cost and the price could reflect the current reliability of equipment in a dynamic way. The generation risk is also considered in competitive bidding. The bidding strategy based on this model helps the power plant acquire the optimal benefit. 相似文献
3.
【研究目的】拟在对征地的多种安置方式进行成本分析基础上,以杭州市虾龙圩村被征耕地为例,研究征地中各种安置方式的成本差异;【研究方法】采用区片综合地价法、社会保障法和基准地价法分别计算货币安置、社会保障安置和留用地安置的安置成本;【结果】货币安置没有考虑到土地预期收益、土地的增值性,安置成本最低,社会保障安置易受被征耕地面积、劳动力人口比例影响,安置成本略高于货币安置的成本,留用地安置考虑到了土地区位,区域经济经济情况等影响土地价格的因素,安置成本最高;【结论】由于各类安置方式的补偿目标、补偿手段、费用计算方法不同,政府当期或近中期支付成本迥异。 相似文献
4.
MARKAL is a generic model tailored by the input data to represent the evolution over a period of usually 40 to 50 years of a specific energy system at the national, regional, state or province, or community level. The database specifies the energy demands -industrial, commercial, residential, and transportation that need to be satisfied over the next several decades. It describes the available sources of supply of energy, either domestic resources or imports of oil, coal, natural gas, nuclear fuel, and renewable. A menu of technologies is provided for extracting, transporting, converting, and using energy, both existing technologies and those expected to be available within the time horizon of the model. The essential characteristics of the technologies are specified, such as their investment cost, operating and maintenance costs, service life, fuel use, efficiency, availability, output, and maximum expected market penetration. As a linear program, the model then chooses the best combination of these technologies to satisfy the projected energy demands. The basic components in a MARKAL model are specific types of energy or emission control technology. Both the supply and demand sides are integrated, so that one side responds automatically to changes in the other. The model selects that combination of technologies that minimizes total energy system cost. In the end, the article describes energy conservation for building in Chongqing. 相似文献
5.
At present, when the enterprises that have implemented the SCM chose co - vendors, all kinds of methods have been employed to appraise them. These results are always influenced by the members' subjective attitude at any rate. Based on the fact that the cost is the most important factor when choosing, and according to the requirement of the enterprise on the supply chain, the authors research the cost's component on supply chain. The cost includes: quality cost, price cost, stock cost, OOS cost, transportation cost and other cost. By calculating the products'practical cost synthetically , the enterprises could choose the vendors whose cost is cheapest as their co - vendors. The calculate cost is an objective and feasible method to choosing vendors reasonably. Finally, some examples and related discussion are given. 相似文献
6.
The quantity of work is needed to calculate the cost in tender offer and bidding. We represent the characteristic of KQML and put forward the idea of constructing the cost calculation system, which includes quantities calculation agents and cost calculation agents, applicable for not only tender bidding but also tender offer. The emphasis is to construct the communications mechanism between two kinds of agents by KQML. Then a communications application example between two kinds of Agent is depicted. 相似文献
7.
The significance and current-situation of running remote maintenance are introduced. The model of maintenance service system is built on the basis of studying units. The system construction, software and hardware environment are debated. The signal monitoring software system of compressor is implemented by programming with assemble language and C language. The virtual instrument applied to on/off-line signal processing is established on the basis of Labwiew. The maintenance decision supporting system interior enterprise with TCP&UDP and the remote maintenance service system adopting B/S model are dwelled. The system is practicability testified. The goal of system developing is the integrated of all kinds of MIS. 相似文献
8.
The study for dealing with the load model in composite system reliability evaluation is almost at a standstill because of the inherent computational complexity. In this paper, an algorithm for composite system reliability evaluation considering load model is proposed. This method is powerful in computation because it can avoid unnecessary state enumeration by means of the relationship among basic reliability informations of load levels. As an example, the IEEE 24-node Reliability Test System is tested on VAX-11/750 computer. The average CPU time to calculate the reliability indices of the system corresponding to a load level is about 5 seconds. 相似文献
9.
Based on the status of CBM (Condition Based Maintenance) in domestic and abroad, the authors propose a GSDM (Grey Situation Decision Making) method of CBM strategy for power transformers. The countermeasure set of CBM for power transformers includes the five typical maintenance schemes, such as the off line maintenance, priority plan overhaul, surveillant operation, periodic overhaul and postponed overhaul. Taking the safety and economy into account, the five qualitative evaluation indexes of decision making, such as security, reliability, maintainability, economy and monitoring feasibility, are proposed, and the quantitative method of the qualitative evaluation indexes is presented. Through constructing situation effect vectors of GSDM, the optimal maintenance strategy for power transformers can be obtained on the base of the grey relational grade between the situation effect vectors and the optimal situation effect vectors. The examples of the CBM scheme for two power transformers in service are provided to illustrate the specific process of the decision making method and to verify its effectiveness. 相似文献
10.
After analyzing the current researches with the three-major-goal management: quality,cost and time,on the construction project and aiming at the existing issues,this article puts forward a new method.This method identifies the reliability of every fundamental module(subsystem) suitably,which based on the current standards to analyze and classify the large construction procedure,and was constituted by the construction procedure.Also was considered the three-major-goal(quality,cost and time) of every module.Then the reliability of the large construction project was calculated,the qualified standards of reliability were evaluated,and the general and particular frame was optimized.Furthermore,it raises a new conception of the comprehensive control technique considering the reliability of the three-major-goal synthetically.This article explores a new way to ensure the three major unified goals: quality,cost and time,of the construction project management,and makes sure that the process of the construction project was in an ideal condition. 相似文献
11.
Super-tall building structures have the features of complex structural systems, diverse structural functions, long service life, massive investment and fixed owners. The life-cycle cost of super-tall building structures mainly contains initial cost, maintenance cost, failure cost caused by hazard and demolition cost. In order to achieve the minimization of the life-cycle cost of the super-tall building structure, a multi-dimensional life cycle economic cost assessment method is proposed in this study. The proposed method considers alternative design schemes, structural components and cost items. The overall cost management and optimization will be done at the initial phase of the structural project if this method can be employed. The proposed method is applied to a super tall building to illustrate its effectiveness and applicability. 相似文献
12.
Photovoltaic power generation is considered to be one of the most promising power generation forms. It is difficult to accurately assess the reliability of the photovoltaic system (PVS) for the volatility and intermittent of the light intensity. By analyzing PVS component failure modes and their impacts on PVS output power, the reliability model of PVS is built. Then the probability model of PVS output power is presented by considering both illumination uncertainty and PVS component random faults. According to the influence of components random faults outside the intentional islands on the reliability of load points inside the intentional islands, the concepts of repair zone, isolation zone and zero zone are defined. Furthermore, by considering the fail-operation of breaker and fuse, the concept for zone hierarchy is proposed, and the analytical formulas to calculate reliability indices of the load points inside the intentional islands are deduced. The application of the presented reliability evaluation model is clarified using a typical example to show the practicality and validity of the proposed approach. 相似文献
13.
Based on the structure of cost factor in transmission lines project and the characteristic of neural networks, the paper shows up using artificial neural networks to estimate the cost of project and provide a method to investigate them. By analyzing the structure of project cost and influence factor, the paper builds both input and output neural cell for cost of transmission line project. The paper builds the model of artificial neural networks and exports the steps of the algorithmic. The project sample is used in history to train and test the model. At last, the model gets satisfactory result and meets the investigation requirement of engineering budgetary estimation. Therefore, the paper provides an impersonality and quick investigation method for budgetary estimation of power projects. 相似文献
14.
Intermittent operation can affect the heat exchange performance of the vertical ground source heat pump system, thereby affecting life cycle cost (LCC) of the ground source heat pump system. The simulation analysis on the hourly load of an office building is implemented by using the DeST software.The heat exchange model of vertical ground heat exchanger pipe-group and energy consumption model of per part of heat pump system are established. Through the comparison between calculation results of continuous operation for 15 years and calculation results of intermittent operation 15 years of the heat pump system, it can be concluded that the LCC value of intermittent operation decreased by 13.45%,relative to the LCC value of continuous operation, and the average energy saving rate of intermittent operation mode is 17.20% in the entire life cycle. Intermittent operation mode can effectively improve energy efficiency of the ground source heat pump system and reduce the LCC value. 相似文献
15.
Resolving traffic assignment problems with a logit model will result in some error because of the correlation of the trip cost and the flux, whereas the application of the random equilibrium assignment model is confined for its complex arithmetic. An amelioration of the logit model and a step by step arithmetic are implemented. The improved model is simple, rational and easily resoluted and the relationship of the trip cost and flux is also considered, therefore, it is applicable for the congested assignment problem and possesses widely applying prosperity. 相似文献
16.
Vacuum Circuit Breaker''s Condition Simulation Based on Artificial Neural Network and Electrical Endurance Quality Criterion 总被引：1，自引：0，他引：1
How to select the factors that have more great affection on the condition based maintenance and how to make sure the relation among them are two key problems. A new method's proposed for vacuum circuit breaker's condition based maintenance, which combines electrical endurance quality criterions and condition recognition arithmetic based on artificial neural network. The paper proposes a model based on electrical-endurance quality criterions by applying ANN in vacuum circuit breaker's condition based maintenance. The simulation indicates that the criterion selected in this way are reasonable and the network with new learning error function has a much better generalization ability. 相似文献
17.
Design of GIS-based monitoring and maintenance decision support system for urban sewage pipe network
Monitoring and maintenance of sewer system is important to city water environmental management. A method for pipeline monitoring and maintenance decision support system (PMMDSS) based on geologic information system (GIS) and decision making system (DSS) is developed for upgrading sewer system maintaining efficiency. Visual basic (VB) and standardized Active X components are employed in PMMDSS, which selected SuperMap Objects as the development platform. PMMDSS integrates the spatial and model system to achieve the decision analysis for the sewer system monitoring and maintenance. An application Software is developed based on a case study in Yuechi Country of Sichuan Province. The software can be used to dynamically monitor the heath condition and provide an optimum visual decision making platform for the city sewer system. 相似文献
18.
It is usually ignored in the traditional EOQ model that the opportunity cost results from lost sales when the enterprise has no commodity in the wearhouse. This paper focuses on some operating enterprise.Under the condition of time_limited partial back_orders and non_instant supply,an EOQ model is established of which it is more reasonable to assume the loss of without commodity in the warehouse divided into two parts:the opportunity cost due to lost sales and the shortage cost.It is discussed that the general cost function and the optimal solution to minimizing the total cost.The new basis of the decision of store system management is provided.Moreover,the model is applied to the example. 相似文献
19.
The service frequency is an important factor which shows the supply and service level of public transportion. By considering the effect of occupancy rate on generalised cost firstly, the authors establish a new public transport model based on generalised cost. Then from the view of optimal pricing, this paper constructs two optimal service frequency models by the aim of maximizing social welfare and maximizing profit separately. The result shows that, without the effect of externalities, the two optimal service frequency is the same. Finally, this paper use some parameters of generalised cost, which coming from a city, to simulate this model, and the result shows it is feasible. 相似文献
20.
In order to calculate and analyze the effect of two transmission lines in parallel on the reliability evaluation of bulk power system, a model including independent outage, common mode outage and dependent outage of these lines is deduced and a new algorithm corresponding to the model is presented. Two transmission lines in parallel including common mode outages and dependent outages can be really simulated as a multi-state component. While reliability indices are calculated, the probability and frequency of independent outage, common mode outage and dependent outage of a system failure state can be calculated at the same time, and computation complexity is reduced. The proposed model and algorithm are applied to the RBTS system, IEEE One Area RTS96 system and a real power system for reliability computation and analysis. Results show that the new algorithm is credible and validity. 相似文献