In this paper, a new generalised class of higher order (F, alpha, rho, d)-V-type I function is introduced for a non-smooth multi-objective fractional programming problem involving support functions. The newly defined ...
详细信息
In this paper, a new generalised class of higher order (F, alpha, rho, d)-V-type I function is introduced for a non-smooth multi-objective fractional programming problem involving support functions. The newly defined class extends several known classes in the literature has been justified through a non-trivial example. In the framework of new concept, we determine conditions under which a fractional function becomes higher order (F, alpha, rho, d)-V-type I function and do some computational work to substantiate the analysis. Further, we establish Karush-Kuhn-Tucker type sufficient optimality conditions and derive various duality results for higher order Mond-Weir type and Schaible type dual programs.
This work proposes a periodic bus holding control method where the bus holding times of all running trips are computed simultaneously within each optimization time period;thus, increasing the coordination among runnin...
详细信息
This work proposes a periodic bus holding control method where the bus holding times of all running trips are computed simultaneously within each optimization time period;thus, increasing the coordination among running buses for avoiding bus bunching. This paper considers the adverse effects of the bus holding control in the in-vehicle travel times of on-board passengers and performs holistic bus holding decisions by modelling the bus holding problem as a discrete, nonlinear, constrained optimization problem. Given the computational complexity of the bus holding problem, an alternating minimization approach is introduced for computing the optimal holding times at each optimization instance. The performance of the periodic control method is evaluated against the performance of event-based control methods using 5-month automated vehicle location and automated passenger count data from bus line 1 in Stockholm for contacting simulation-based experiments.
On the basis of Robinson's normal equation and smoothing projection operator, a homotopy method for solving mathematical programs with box-constrained variational inequalities (MPBVI) is presented. In which, the C...
详细信息
On the basis of Robinson's normal equation and smoothing projection operator, a homotopy method for solving mathematical programs with box-constrained variational inequalities (MPBVI) is presented. In which, the Chen-Harker-Kanzow-Smale smooth function is used to transform MPBVI into a smooth optimization problem. Under some mild assumptions, the existence and global convergence of a smooth path from almost any initial point to the GKKT point of the approximate problems is proven. And, the convergence of the GKKT point to a strong C-stationary point of the original problems is proved. Finally, some numerical results are given to show the effectiveness and feasibility of the homotopy method.
It is well known that each convex function f:Rn?R is supremally generated by affine functions. More precisely, each convex function f:Rn?R is the upper envelope of its affine minorants. In this paper, we propose an al...
详细信息
It is well known that each convex function f:Rn?R is supremally generated by affine functions. More precisely, each convex function f:Rn?R is the upper envelope of its affine minorants. In this paper, we propose an algorithm for solving reverse convex programming problems by using such a representation together with a generalized cutting-plane method. Indeed, by applying this representation, we solve a sequence of problems with a smaller feasible set, in which the reverse convex constraint is replaced by a still reverse convex but polyhedral constraint. Moreover, we prove that the proposed algorithm converges, under suitable assumptions, to an optimal solution of the original problem. This algorithm is coded in MATLAB language and is evaluated by some numerical examples.
Based on a singular value analysis conducted on the Dai-Liao conjugate gradient method, it is shown that when the gradient approximately lies in the direction of the maximum magnification by the search direction matri...
详细信息
Based on a singular value analysis conducted on the Dai-Liao conjugate gradient method, it is shown that when the gradient approximately lies in the direction of the maximum magnification by the search direction matrix, the method may get into some computational errors and also, the convergence may occur hardly. Hence, we obtain a formula for computing the Dai-Liao parameter which makes the direction of the maximum magnification by the search direction matrix to be orthogonal to the gradient. We briefly discuss global convergence of the corresponding Dai-Liao method with and without convexity assumption on the objective function. Numerical experiments on a set of test problems of the CUTEr collection show practical effectiveness of the suggested adaptive choice of the Dai-Liao parameter in the sense of the Dolan-More performance profile.
Ultra-wideband (UWB) technology is one of the most promising wireless communication technologies. Examples of UWB applications include, among others, radiocommunication devices and location systems, due to their opera...
详细信息
Ultra-wideband (UWB) technology is one of the most promising wireless communication technologies. Examples of UWB applications include, among others, radiocommunication devices and location systems, due to their operating range, ability to work in outdoor environments, and resistance to multipath effects. This article focuses on the use of UWB technology in constructing a guide localization system for an unmanned ground vehicle (UGV), which is one of the stages of implementing a "follow me" system. This article describes the complete process of UWB signal processing from its acquisition, methods of filtering, and obtained results, to determining the location of the guide. This article examines the possibility of using modified versions of localization algorithms for determining the guide's location, including trilateration, methods of nonlinear programming, and a geometric algorithm proposed by us. The innovation of this study consists in the implementation of an algorithm that changes the selection of equations (mathematical model) for determining location based on the number of available measurements from UWB sensors.
Modelling dependent credit-rating migrations of assets classified into M credit classes and S industries, M x S + 2(MxS) parameters have to be estimated. For a realistic choice of M and S, this number is huge and it g...
详细信息
Modelling dependent credit-rating migrations of assets classified into M credit classes and S industries, M x S + 2(MxS) parameters have to be estimated. For a realistic choice of M and S, this number is huge and it greatly exceeds the number of available observations. To avoid brute-force calculations, we suggest sequential and parallel genetic algorithms. Considering a practically important combination of M = 7 and S = 6, the approach is tested on Standard and Poor's data.
A two-stage batch estimation algorithm for solving a class of nonlinear, static parameter estimation problems that appear in aerospace engineering applications is proposed. It is shown how these problems can be recast...
详细信息
A two-stage batch estimation algorithm for solving a class of nonlinear, static parameter estimation problems that appear in aerospace engineering applications is proposed. It is shown how these problems can be recast into a form suitable for the proposed two-stage estimation process. In the first stage, linear least squares is used to obtain a subset of the unknown parameters (set 1) and a residual sampling procedure is used for selecting initial values for the rest of the parameters (set 2). In the second stage, depending on the uniqueness of the local minimum, either only the parameters in the second set need to be re-estimated, or all the parameters will have to be re-estimated simultaneously, by a nonlinear constrained optimization. The estimates from the first stage are used as initial conditions for the second-stage optimizer. It is shown that this approach alleviates the sensitivity to initial conditions and minimizes the likelihood of converging to an incorrect local minimum of the nonlinear cost function. An error bound analysis is presented to show that the first stage can be solved in such a way that the total cost function will be driven to the optimal cost, and the difference has an upper bound. Two tutorial examples are used to show how to implement this estimator and compare its performance to other similar nonlinear estimators. Finally, the estimator is used on a 5-hole Pitot tube calibration problem using flight test data collected from a small unmanned aerial vehicle that cannot be easily solved with single-stage methods.
Amine-based chemical absorption has become the most mature technology among carbon dioxide capture processes, featuring the advantages of high separation efficiencies and its simplicity to attach it to existent indust...
详细信息
Amine-based chemical absorption has become the most mature technology among carbon dioxide capture processes, featuring the advantages of high separation efficiencies and its simplicity to attach it to existent industrial facilities. Nevertheless, further improvements on its performance are required in order to implement this technology to a wider extent. Energy expenditure at the solvent regeneration unit has been remarked as the major drawback of the process under discussion;therefore, the main objective of this work is to compute optimal operating policies which ensure minimum heat load at the reboiler along with reasonable removal efficiencies. A deterministic mathematical model of a reported pilot plant was deployed as the basis for the nonlinear programming optimization formulations, using a rate-based approach and an eNRTL thermodynamic framework. Several optimization scenarios were studied to account for diverse capture targets and degrees of freedom. Furthermore, sensitivity analyses were performed to understand the stand-alone effect of some variables on the process. Results reflect the importance of optimizing the complete plant to account for significant interactions between variables, as well as choosing an operational arrangement according to the separation goal demanded.
Phasor measurement units (PMUs) can obtain synchronized voltage and current phasors to increase the accuracy of state estimation results. Optimal PMU placement (OPP) reduces the required number of PMUs to make the sys...
详细信息
Phasor measurement units (PMUs) can obtain synchronized voltage and current phasors to increase the accuracy of state estimation results. Optimal PMU placement (OPP) reduces the required number of PMUs to make the system fully observable. In this paper, two mathematical programming formulations, which are mixed integer linear programming (MILP) and nonlinear programming (NLP), for power grid observability modeling to solve the OPP problem are presented. Power flow and zero injection measurement modeling along with restricted communication facilities, PMU failure, and limited channel capacity contingencies are investigated. MILP zero injection formulation is improved to overcome the observability redundancy and optimality drawbacks. A new formulation for nonlinear programming-based PMU placement for zero injection measurement is proposed. MILP and NLP methods are compared to illustrate the advantages and disadvantages of each method. The comparison and proposed formulations are examined on IEEE 14-, 57-, 118-, 300-bus test systems and a large 2383-bus Polish system to demonstrate their effectiveness.
暂无评论