Differential Evolution (DE) is featured by its simple parameter control;genetic operation and fine robustness. However, DE yet still has difficulty with complex functions in continuous space due to its searching blind...
详细信息
ISBN:
(纸本)9780769536545
Differential Evolution (DE) is featured by its simple parameter control;genetic operation and fine robustness. However, DE yet still has difficulty with complex functions in continuous space due to its searching blindness and inefficiency from time to time. An adaptive DE algorithm based on LS-SVM (Least Square Support Vector Machine) is proposed in this paper. The key genetic operators such as differential mutation and crossover are modified;Adaptive population evolution guiding strategy based on LS-SVM n-best training set approximation and optimization is designed;With applying condition analyzed, the procedure and complexity of the LS-SVM based evolution guiding strategy is summarized. The comparative results of the proposed DE with traditional one based on various standard test functions effectively demonstrate the high accuracy and efficiency of the proposed approach for continuous multi-modal optimization.
Tato bakalářská práce se zabývá implementací aproximační funkce do mikroprocesoru PIC. Zaměřuje se na architekturu mikroprocesorů a rozbor aproximačních funkcí. Pro samotn...
详细信息
Tato bakalářská práce se zabývá implementací aproximační funkce do mikroprocesoru PIC. Zaměřuje se na architekturu mikroprocesorů a rozbor aproximačních funkcí. Pro samotnou implementaci je pak vybrána metoda nejmenších čtverců a to z důvodu její relativní jednoduchosti a přesnosti v porovnání s ostatními metodami. Mikroprocesor má pomocí A/D převodníku změřit závislost nelineárního systému, jenž je k mikroprocesoru připojen. Měří se napětí na logaritmickém potenciometru, který reprezentuje nelineární systém, v závislosti na poloze jezdce odporové dráhy. Poté, pomocí zvolené metody, mikroprocesor dopočítá charakteristiku nelineárního systému. Naměřené hodnoty se porovnávají s teoretickými, které byly dopočítaný zvolenou metodou. Hodnoty naměřené, teoretické a jejich diference se pak zobrazují na displeji, připojeném rovněž k mikroprocesoru. V závěru se pak diskutují výsledky spolu s možností dalšího rozvinutí této práce.
Enantioselective chromatographic methods, representing the most commonly used techniques for the determination of enantiomeric ratios, can also be used for the evaluation of stereochemical integrity. In the present st...
详细信息
Enantioselective chromatographic methods, representing the most commonly used techniques for the determination of enantiomeric ratios, can also be used for the evaluation of stereochemical integrity. In the present study, dynamic capillary electrokinetic chromatography (DEKC) was employed to determine the enantiomerization barrier of thalidomide. In the presence of the chiral mobile phase additive carboxymethyl-beta -cyclodextrin, the interconverting enantiomers of thalidomide produced characteristic elution profiles exhibiting plateaus and/or peak broadening between 25 and 55 degreesC at pH 8. To obtain the enantiomerization barrier of thalidomide from experimental data, the fast and efficient simulation program ChromWin was used to simulate the experimental interconversion profiles and to obtain the apparent rate constants k(1)(app)(T). Additionally, these values were compared with the novel approximation function for the direct calculation of enantiomerization barriers from chromatographic parameters of elution profiles. From the rate constants k(1)(app)(T) of temperature-dependent measurements the kinetic activation parameters DeltaG(T)(#),DeltaH(#), and DeltaS(#) of the enantiomerization of thalidomide were obtained. At 25 degreesC, the enantiomerization barrier DeltaG(#) was determined to be 102 +/- 1 kJ/mol at pH 8 in the dynamic electrokinetic chromatographic experiment.
Image vignetting is one of the major radiometric errors that occur in lens-camera systems. In many applications, vignetting is an undesirable effect;therefore, when it is impossible to fully prevent its occurrence, it...
详细信息
Image vignetting is one of the major radiometric errors that occur in lens-camera systems. In many applications, vignetting is an undesirable effect;therefore, when it is impossible to fully prevent its occurrence, it is necessary to use computational methods for its correction. In probably the most frequently used approach to the vignetting correction, that is, the flat-field correction, the use of appropriate vignetting models plays a pivotal role. The radial polynomial (RP) model is commonly used, but for its proper use, the actual vignetting of the analyzed lens-camera system has to be a radial function. However, this condition is not fulfilled by many systems. There exist more universal models of vignetting;however, these models are much more sophisticated than the RP model. In this article, we propose a new model of vignetting named the Deformable Radial Polynomial (DRP) model, which joins the simplicity of the RP model with the universality of more sophisticated models. The DRP model uses a simple distance transformation and minimization method to match the radial vignetting model to the non-radial vignetting of the analyzed lens-camera system. The real-data experiment confirms that the DRP model, in general, gives better (up 35% or 50%, depending on the measure used) results than the RP model.
Image vignetting is one of the major radiometric errors, which occurs in lens-camera systems. In many applications, vignetting is an undesirable phenomenon;therefore, when it is impossible to fully prevent its occurre...
详细信息
Image vignetting is one of the major radiometric errors, which occurs in lens-camera systems. In many applications, vignetting is an undesirable phenomenon;therefore, when it is impossible to fully prevent its occurrence, it is necessary to use computational methods for its correction in the acquired image. In the most frequently used approach to the vignetting correction, i.e., the flat-field correction, the usage of appropriate vignetting models plays a crucial role. In the article, the new model of vignetting, i.e., Smooth Non-Iterative Local Polynomial (SNILP) model, is proposed. The SNILP model was compared with the models known from the literature, e.g., the polynomial 2D and radial polynomial models, in a series of numerical tests and in the real-data experiment. The obtained results prove that the SNILP model usually gives better vignetting correction results than the other aforementioned tested models. For images larger than UXGA format (1600x1200), the proposed model is also faster than other tested models. Moreover, among the tested models, the SNILP model requires the least hardware resources for its application. This means that the SNILP model is suitable for its usage in devices with limited computing power.
In this paper, a new method is proposed for trip distribution forecasting in multi-commodity transportation ' networks. In this new approach, real trip distributions at present are modeled by approximation functio...
详细信息
In this paper, a new method is proposed for trip distribution forecasting in multi-commodity transportation ' networks. In this new approach, real trip distributions at present are modeled by approximation functions for each commodity. In large-scale multi-commodity transportation networks, these functions could be obtained by parts of network as training data, without losing generality of the algorithm. Of course, it will have an influence on the approximation. Then, a fuzzy model for trip distribution forecasting calibrates these functions. This model considers all adjustments simultaneously. In order to show the application of the new method, a numerical example is given and solved.
The axially chiral allenes dimethyl-1,3-allenedicarboxylate 1 and diethyl-1,3-allenedicarboxylate 2 show characteristic plateau formation during enantioselective GC separation on the chiral stationary liquid phase Chi...
详细信息
The axially chiral allenes dimethyl-1,3-allenedicarboxylate 1 and diethyl-1,3-allenedicarboxylate 2 show characteristic plateau formation during enantioselective GC separation on the chiral stationary liquid phase Chirasil-beta-Dex. The elution profiles, obtained from temperature-dependent dynamic GC (DGC) experiments (1: 100-140degreesC;2: 110-150degreesC) were evaluated with the recently derived approximation function (AF) k(1)(approx) = f (t(R)(A), t(R)(B), h(plateau), N) to yield the enantiomerization rate constant directly k(1). These values were compared with those obtained by computer-aided simulation with ChromWin. The Eyring activation parameters of the experimental interconversion profiles were determined to be: DeltaG(#)(298.15 K) = 103.6 +/- 0.9 kJ mol(-1), DeltaH(#) = 44.7 +/- 0.4 kJ mol(-1), DeltaS(#) = -198 +/- 7 J K-1 mol(-1) for dimethyl-1,3-allenedicarboxylate 1, and DeltaG(#)(298.15 K) = 103.5 +/- 1.1 kJ mol(-1), DeltaH(#) = 44.7 +/-0.5 kJ mol(-1), DeltaS(#) = -197 +/- 9 J K-1 mol(-1) for diethyl-1,3-allenedicarboxylate 2. The approximation function (AF) presented here allows the fast determination of rate constants k(1) and activation barriers of enantiomerization DeltaG(#) from chromatographic parameters without extensive computer simulation.
This paper addresses the optimal collision-free trajectory planning problem for autonomous ground vehicles(AGVs)in the presence of probability constraints. Within a computational framework based on optimal control, a ...
详细信息
ISBN:
(数字)9789887581581
ISBN:
(纸本)9798350366907
This paper addresses the optimal collision-free trajectory planning problem for autonomous ground vehicles(AGVs)in the presence of probability constraints. Within a computational framework based on optimal control, a strategy employing a conservative approximation function is proposed to solve the nonlinear trajectory optimization problem for AGVs under probability constraints. This strategy utilizes an approximation function based on hyperbolic tangent functions to replace probability constraints in trajectory optimization with deterministic constraints expressed explicitly, thereby transforming the original AGV trajectory optimization problem with probability constraints into a parameterized nonlinear programming problem. Furthermore,it is proven that the optimal solution under this approximation strategy converges to the optimal solution of the original ***, numerical results validate the reliability and optimality of this strategy in solving collision-free trajectory optimization problems for AGVs under probability constraints.
暂无评论