This paper presents a parametric optimization task of steel conic shell towers of wind-powered generators. The minimum weight of the steel tower has been considered as purpose function when produced capacity of the wi...
详细信息
This paper presents a parametric optimization task of steel conic shell towers of wind-powered generators. The minimum weight of the steel tower has been considered as purpose function when produced capacity of the wind-powered generators has been fixed at the target level. The tower's height, diameters of the middle surface of the tower's conic shell at the base level and at a height if the wind turbine installation, thicknesses of the tower's conic shell, and also the diameter of the wind wheel were considered as design variables. The wind loads applied on steel shell tower have been presented in dependence of design variables and considered as state variables. The optimization problem formulated as non-linear programming task has been solved by improved gradient method. Optimum design decisions of the steel conic shell towers for the wind-powered generators with produced capacity of wide range have been defined. An optimum tower's height and weight in dependence of produced capacity of wind-powered generators have been plotted.
We consider the planning of pulp production for large sulphate and sulfite mills. The production planning problem is formulated as a non-linear program (NLP) given a process model of the mill as constraint. The object...
详细信息
We consider the planning of pulp production for large sulphate and sulfite mills. The production planning problem is formulated as a non-linear program (NLP) given a process model of the mill as constraint. The objective is to minimize the usage of expensive chemicals and to minimize the (squared) deviation from specified set-points for selected variables, e.g. production, tank-level and chemical composition of the cooking liquor. The problem formulation also considers upper and lower limits on variables and limitations in the derivative of production related variables. The NLP, which involves several tens of thousands of variables, is solved using algorithms for large-scale optimization. To provide a correct initial state of the process model, a moving horizon estimation is done to estimate the current state of the process. A model library consisting of common process units in pulp mills have been developed. The models are described by differential algebraic equations. A software platform, which enables the user to assemble complex process models of complete mills based on the model library, has been developed. The platform also serves as data collector for the measured values from process sensors, as well as storing optimized and estimated values. The pulp mill production planning system is installed on-line at Billerud Gruvön, a large Swedish integrated pulp and paper mill, producing some 660000 tons of sulphate and sulfite pulp.
This paper deals with the thermal diagnosis on a D.C. motor working with steady or variable speed. This supervision is performed by means of parameter identification of a thermal model with parameters depending on ang...
详细信息
This paper deals with the thermal diagnosis on a D.C. motor working with steady or variable speed. This supervision is performed by means of parameter identification of a thermal model with parameters depending on angular speed. The model parameter is estimated by minimizing the output error by means of a nonlinearprogramming according to the Marquardt algorithm. The method used allows characterizing and distinguishing several thermal behaviours.
In order to improve the performance of time difference of arrival(TDOA)localization,a nonlinear least squares algorithm is proposed in this ***,based on the criterion of the minimized sum of square error of time diffe...
详细信息
In order to improve the performance of time difference of arrival(TDOA)localization,a nonlinear least squares algorithm is proposed in this ***,based on the criterion of the minimized sum of square error of time difference of arrival,the location estimation is expressed as an optimal problem of a non-linear ***,an initial point is obtained using the semi-definite *** finally,the location is extracted from the local optimal solution acquired by Newton *** results show that when the number of anchor nodes is large,the performance of the proposed algorithm will be significantly better than that of semi-definite programming approach with the increase of measurement noise.
The paper presents the method of assigning and results of simulation safe trajectory to avoid a collision at sea. There have considered meeting situations a few ships encounter. The process is described as a task non-...
详细信息
The paper presents the method of assigning and results of simulation safe trajectory to avoid a collision at sea. There have considered meeting situations a few ships encounter. The process is described as a task non-linear progranuning with using maximum principle. The paper contains examples of simulations.
Waves and currents interact, with the resulting combination largely determining the loading on offshore structures and devices. Despite this, currents are often ignored and wave buoy data is processed without consider...
详细信息
Waves and currents interact, with the resulting combination largely determining the loading on offshore structures and devices. Despite this, currents are often ignored and wave buoy data is processed without consideration of the current or the wave-current interaction. This data is subsequently used in design, yet sea state power, steepness, and directionality may have significant errors. Here we present a novel framework for the processing of wave buoy data to account for the effect of a current. We use a mesh adaptive direct search (MADS) algorithm to solve for the current and current-modified wave parameters simultaneously. Through 125 simulated directional wave-current sea states, we demonstrate the performance of the method under a wide range of conditions;including bimodal sea states with non-colinear current. Current speed and direction are estimated accurately for all cases (mean RMSE of 0.1179ms(-1) and 0.0091 rad respectively) which enables sea state steepness and power to be estimated within +/- 3%. Ignoring this current of +/- 2(-1) when deriving these wave parameters results in errors up to 30%. This work demonstrates that it is possible to correctly process wave buoy measurement data to account for, and quantify, a current thus significantly reducing the uncertainty of the ocean conditions. After further validation work, the framework can be widely applied to historic datasets, correcting the wave data and providing an additional dataset of current velocities.
This study mainly focuses on the design of a new cantilever structure and its minimal mass optimization subject to yield and buckling constraints. Given a vertical force in a constant distance from a vertical wall, th...
详细信息
This study mainly focuses on the design of a new cantilever structure and its minimal mass optimization subject to yield and buckling constraints. Given a vertical force in a constant distance from a vertical wall, the minimal mass design of a two elements structure with and without anchorage length limitation of the wall is first studied. To further reduce the total structural mass of, a sector cantilever structure is proposed, and the advantage of choosing equal bar length and connecting strings to the center of a circle is proved. Given finite anchorage length of the wall, a tailored sector cantilever structure with finite anchorage length is proposed. Minimal mass design of the sector cantilever with and without anchorage length constraint can be obtained by processing a constrained nonlinear optimization of shape parameters. Considering the penalty of joint mass, the optimal complexity of the sector cantilever will decrease as the penalty coefficient increases. Numerical results are given to show the efficiency of the proposed cantilever structures in saving mass.
This paper is an effort to evolve multivariate variable control charts in a fuzzy environment where each observation in each sample is assumed to be a canonical fuzzy number. To do this, a likelihood ratio test should...
详细信息
This paper is an effort to evolve multivariate variable control charts in a fuzzy environment where each observation in each sample is assumed to be a canonical fuzzy number. To do this, a likelihood ratio test should be exploited in a fuzzy environment, because multivariate variable control charts are constructed using this test. In this way, membership functions of likelihood ratio statistics applied to control the process mean and dispersion are obtained solving four non-linear programming problems. Using these membership functions, membership degrees of in and out of control states of both process mean and dispersion are computed. Hence contrary to the classic multivariate variable control charts categorizing the process into just two states, i.e. in and out of control, the process can be considered in several intermediate states, based on the computed membership degrees, bringing about more flexibility in process analysis.
This paper presents the utilization of SISCON, a the software package meant to be utilised in the evaluation of optimal decisions for large scale systems. The large scale systems have generally a complex structure and...
详细信息
This paper presents the utilization of SISCON, a the software package meant to be utilised in the evaluation of optimal decisions for large scale systems. The large scale systems have generally a complex structure and consequently a global computation approach cannot be effectively carried out if at all. First the decomposition of large–scale problems is carried out. Then the subproblems are solved by using standard optimization techniques. SISCON offers opportunities for solving non-linear mathematical programming problems and for evaluating optimal decisions in large scale systems control. SISCON firstly evaluates mathematical models developed from experimental data using LS least square methods for linear and nonlinear systems and after that then computes the optimal decision solution by solving the mathematical non-linear programming problems.
The problem of determining economic production quantities and demands, with respect to prices for a hybrid manufacturing / remanufacturing system is addressed in this paper. Most of studies in the literature consider ...
详细信息
The problem of determining economic production quantities and demands, with respect to prices for a hybrid manufacturing / remanufacturing system is addressed in this paper. Most of studies in the literature consider same market for new and remanufactured (as-good-as new assumption) and separate production line. We consider in this paper that products are processed on a common line and are sold in distinct market with price sensitive demands. The problem is modelled and solved with a non-linear model. A numerical analysis is developed to validate the model and analyze its feasibility and limits.
暂无评论