检索结果-内蒙古大学图书馆

Efficient aircraft spare parts inventory management under demand uncertainty

JOURNAL OF AIR TRANSPORT MANAGEMENT 2015年 42卷 101-109页

作者： Gu, Jingyao Zhang, Guoqing Li, Kevin W. Univ Windsor Fac Engn Supply Chain & Logist Optimizat Res Ctr Windsor ON N9B 3P4 Canada Univ Windsor Odette Sch Business Windsor ON N9B 3P4 Canada

In airline industries, the aircraft maintenance cost takes up about 13% of the total operating cost. It can be reduced by a good planning. Spare parts inventories exist to serve the maintenance planning. Compared with commonly used reorder point system (ROP) and forecasting methods which only consider historical data, this paper presents two non-linear programming models which predict impending demands based on installed parts failure distribution. The optimal order time and order quantity can be found by minimizing total cost. The first basic mathematical model assumes shortage period starts from mean time to failure (MITF). An iteration method and GAMS are used to solve this model. The second improved mathematical model takes into account accurate shortage time. Due to its complexity, only GAMS is applied in solution methodology. Both models can be proved effective in cost reduction through revised numerical examples and their results. Comparisons of the two models are also discussed. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： Aircraft maintenance Spare parts Inventory management non-linear programming Failure distribution Iteration method

来源：评论

学校读者我要写书评

暂无评论

Alternating heuristic and exact method for the leader-follower facility location and design problem 12

Alternating heuristic and exact method for the leader-follow...

引用

12th International Conference on Electronics Computer and Computation (ICECCO)

作者： Kochetov, Yury Sokolova, Irina Amirgaliyeva, Saltanat Amirgaliyeva, Zhazira Inst Informat & Computat Technol Pushkin St 125 Alma Ata 050010 Kazakhstan Novosibirsk State Univ Novosibirsk 630090 Russia Suleyman Demirel Univ Kaskelen 040900 Kazakhstan Kazakh Natl Univ Alma Ata 050040 Kazakhstan

ISBN: (纸本)9781509001996

We study the following discrete facility location game. Two players, a leader and a follower, open facilities and compete to attract clients from a given market. Each player has a budget and maximizes own market share. Each client splits own demand probabilistically over all opened facilities by the gravity rule. The goal is to find the location and design of the leader facilities to maximize his market share. We present an alternating heuristic and exact method for this game. We rewrite the problem as mixed integer linear program with exponential number of constraints. In our method, we start with small subset of constraints and iteratively enlarge it until upper and lower bounds not coincide. Computational results are discussed.

关键词： competitive facility location Stackelberg game bi-level optimization metaheuristic non-linear programming

来源：评论

学校读者我要写书评

暂无评论

Developing spreadsheet models of Holt-Winter methods and solving with Microsoft Excel solver and differential evaluation technique: An application to tourism sector 5

Developing spreadsheet models of Holt-Winter methods and sol...

引用

2015 International Conference on Industrial Engineering and Operations Management (IEOM)

作者： Unal, Yusuf Ziya Al-Turki, Umar Mustafa Zaim, Selim Demirel, Omer Fahrettin Gorener, Rifat Fatih Univ Dept Ind Engn Istanbul Turkey King Fahd Univ Petr & Minerals Dept Syst Engn Dhahran Saudi Arabia Istanbul Tech Univ Dept Ind Engn Istanbul Turkey Roosevelt Univ Dept Finance Chicago IL 60605 USA

ISBN: (纸本)9781479960651

Forecasting and Time series techniques are frequently used and play extremely important roles in managerial activities and decision-making processes. Holt-Winters (HW) which is one of the most popular forecasting methods is utilized in cases where data show seasonality and/or trend. The method involves the selection of several parameters for optimum prediction results. Heuristics are usually utilized for optimum parameter selection and it appears to be an open field for improvement. In this study "Spreadsheet modeling" of HW method is improved by minimizing the mean squared error (i.e. prediction error). Since the forecast error is nonlinear function;Holt-Winters parameter optimization in this study is achieved by "Excel nonlinear Solver" and "Differential Evolution Search" techniques. To increase the usability of the spreadsheet modeling advance macro programming techniques are incorporated with the developed models in Microsoft Excel.

关键词： Forecasting Holt-Winters Heuristic Searches non-linear programming Spreadsheet Modeling Microsoft Excel Macro programming

来源：评论

学校读者我要写书评

暂无评论

Optimal Placement of Phasor Measurement Units with linear and non-linear Models

引用

ELECTRIC POWER COMPONENTS AND SYSTEMS 2015年第4期43卷 357-373页

作者： Theodorakatos, Nikolaos P. Manousakis, Nikolaos M. Korres, George N. Natl Tech Univ Athens ECE Dept Athens Greece

Abstract-This article presents a non-linear programming-based model for the optimal placement of phasor measurement units. The optimal phasor measurement units placement is formulated to minimize the number of phasor measurement units required for full system observability and to maximize the measurement redundancy at all buses in a power system. A sequential quadratic programming algorithm is used for the solution of the proposed model. The existence of power flow and injection measurements, the limited phasor measurement units channel capacity, the lack of communication facilities in substations, and the single phasor measurement units loss are also incorporated into the initial proposed formulation. The non-linear programming model is applied to IEEE 14- and 118-bus test systems in MATLAB. The accuracy and the effectiveness of the proposed method is verified by comparing the simulation results to those obtained by a binary integer programming model also implemented in MATLAB. The comparative study shows that the proposed non-linear programming model yields the same number of phasor measurement units as the binary integer programming model. A remarkable advantage of the non-linear programming against binary integer linear programming is its capability to give more than one optimal solution, each one having the same minimum number of phasor measurement units (same minimum objective value), but at different locations.

关键词： binary integer linear programming optimization mixed integer linear programming Phasor measurement unit observability sequential quadratic programming optimal placement non-linear programming

来源：评论

学校读者我要写书评

暂无评论

AN AFFINE SCALING DERIVATIVE-FREE TRUST REGION METHOD WITH INTERIOR BACKTRACKING TECHNIQUE FOR BOUNDED-CONSTRAINED nonlinear programming

引用

Journal of Systems Science & Complexity 2014年第3期27卷 537-564页

作者： GAO Jing ZHU Detong Department of Mathematics Shanghai Normal University

This paper proposes an arlene scaling derivative-free trust region method with interior backtracking technique for bounded-constrained nonlinear programming. This method is designed to get a stationary point for such a problem with polynomial interpolation models instead of the objective function in trust region subproblem. Combined with both trust region strategy and line search technique, at each iteration, the affine scaling derivative-free trust region subproblem generates a backtracking direction in order to obtain a new accepted interior feasible step. Global convergence and fast local convergence properties are established under some reasonable conditions. Some numerical results are also given to show the effectiveness of the proposed algorithm.

关键词： Affine scaling backtracking technique box constrains derivative-free optimization non-linear programming trust region method.

来源：评论

学校读者我要写书评

暂无评论

Optimal Pricing of a Heterogeneous Portfolio for a Given Risk Level

引用

ASTIN Bulletin: The Journal of the IAA 2015年第1期36卷 161-185页

作者： Yaniv Zaks Esther Frostig Benny Levikson Department of Statistics University of Haifa Israel

Consider a portfolio containing heterogeneous risks, where the policyholders’ premiums to the insurance company might not cover the claim payments. This risk has to be taken into consideration in the premium pricing. On the other hand, the premium that the insureds pay has to be fair. This fairness is measured by the distance between the risk and the premium paid. We apply a non-linear programming formulation to find the optimal premium for each class so that the risk is below a given level and the weighted distance between the risk and the premium is minimized. We consider also the dual problem: minimizing the risk level for a given weighted distance between risks and premium.

关键词： Heterogeneous portfolio Positive Definite Matrix non-linear programming dual problem

来源：评论

学校读者我要写书评

暂无评论

Evaluation of Maximum Reliability Using Co-efficient of Variance for Parallel System Model

引用

JOURNAL OF INFORMATION & OPTIMIZATION SCIENCES 2015年第4期36卷 393-403页

作者： Razak, K. Abdul Rajakumar, K. TRP Engn Coll SRM Grp Dept Math Tiruchirappalli Tamil Nadu India Trichy Engn Coll Dept Math Tiruchirappalli Tamil Nadu India

The reliability analysis of a component or a system is an important concept in almost all engineering disciplines. In general, fuzzy sets are used to analyze the system reliability. The system reliability may be formed as linear or nonlinear programming with cost function in fuzzy environment. To analyze the fuzzy system reliability, the reliability of each component of the system is represented as fuzzy number in nature. In this paper, we have presented the parallel system model with fuzzy cost function to evaluate the maximum reliability subject to minimum cost using trapezoidal fuzzy number and to find out the Co-efficient of Variance for each membership function. A numerical example is given to illustrate the model for nonlinear programming and to evaluate the system reliability.

关键词： Fuzzy sets Fuzzy Reliability Parallel system Trapezoidal fuzzy number non-linear programming

来源：评论

学校读者我要写书评

暂无评论

A wavelet hybrid method based on ARIMA and support vector regression forecasts

引用

INTERNATIONAL JOURNAL OF ENERGY AND STATISTICS 2015年第2期3卷 1550007-1-1550007-11页

作者： Teixeira Junior, Luiz Albino Rodrigues, Samuel Bellido Carreno Franco, Edgar Manuel Lindbeck da Silva, Arinei Carlos Fed Univ Latin Amer Integrat Latin Amer Inst Technol Infrastruct & Terr Foz Do Iguacu PR Brazil Univ Fed Parana Postgrad Program Numer Methods Engn Curitiba Parana Brazil State Univ West Parana Dept Elect Engn Cascavel PR Brazil

In this paper, we put forward a new hybrid methodology to generate forecasts of time series. Indeed, the proposed forecaster is a HWCF that integrates the following techniques: wavelet decomposition;ARIMA models;SVRs;wavelet combination of forecasts;and non-linear programming. Basically, the HWCF is able to capture, simultaneously, linear and non-linear auto-dependence structures exhibited by a time series, which are represented, at time t, by both the linear and non-linear combined forecasts: L-C,L-t and N-C,N-t, respectively. After obtaining the combined forecasts L-C,L-t and N-C,N-t, they are summed (i. e., L-C,L-t + N-C,N-t = yh,t), producing the hybrid forecast yh,t, for each instant t. The numerical results show that HWCF achieved relevant accuracy gains in forecasting process of the annual time series of sunspot, when comparing with other ten competitive forecasters.

关键词： Wavelet decomposition ARIMA model support vector regression hybrid wavelet combination non-linear programming

来源：评论

学校读者我要写书评

暂无评论

Newsvendor problem with multiple unreliable suppliers

引用

INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH 2014年第1期52卷 221-242页

作者： Merzifonluoglu, Yasemin Feng, Yazhe Middle E Tech Univ Guzelyurt Turkey Virginia Tech Dept Ind & Syst Engn Blacksburg VA USA

This paper focuses on supplier-related decisions in a newsvendor setting. We build upon the current literature by analysing the newsvendor problem with multiple unreliable and non-identical suppliers. We also incorporate both fixed ordering costs and capacity limits for supplier selection. We develop an exact algorithm to solve the problem optimally and a heuristic algorithm to solve the problem efficiently. Through structural properties of the optimal solution and a numerical study, we provide useful managerial implications regarding optimal sourcing strategies in complex supply chains. Previous literature concludes that with multiple unreliable (independent) suppliers, cost is the order qualifier and reliability is the order winner. We found that when fixed ordering costs and supply capacities exist, this insight no longer holds. We also examine the sensitivity of the sourcing decisions to supplier capacity levels, demand uncertainty, salvage value and shortage cost. Our results show that high levels of demand uncertainty lead firms to turn to a single-sourcing strategy whereas high salvage values and high shortage cost suggest multi-sourcing strategy.

关键词： inventory branch and bound non-linear programming supply chain management

来源：评论

学校读者我要写书评

暂无评论

Impact of a price-maker pumped storage hydro unit on the integration of wind energy in power systems

引用

ENERGY 2014年 69卷 3-11页

作者： Sousa, Jorge A. M. Teixeira, Fabio Faias, Sergio ISEL Lisbon Engn Super Inst Dept Elect Engn & Automat P-1950062 Lisbon Portugal INESC ID Lisbon Portugal

The increasing integration of larger amounts of wind energy into power systems raises important operational issues, such as the balance between power generation and demand. The pumped storage hydro (PSH) units are one possible solution to mitigate this problem, once they can store the excess of energy in the periods of higher generation and lower demand. However, the behavior of a PSH unit may differ considerably from the expected in terms of wind power integration when it operates in a liberalized electricity market under a price-maker context. In this regard, this paper models and computes the optimal PSH weekly scheduling in a price-taker and price-maker scenarios, either when the PSH unit operates in standalone and integrated in a portfolio of other generation assets. Results show that the price-maker standalone PSH will integrate less wind power in comparison with the price-taker situation. Moreover, when the PSH unit is integrated in a portfolio with a base load power plant, the role of the price elasticity of demand may completely change the operational profile of the PSH unit. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： Electricity markets Electricity systems modeling Pumped storage hydro scheduling Price-maker Wind power integration non-linear programming

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：