Translating local electro/nucleophilicities into the language of reactive sites is an appealing theoretical challenge that could be conducive to strengthen the collaborative dialogue between experimentalists and quant...
详细信息
Translating local electro/nucleophilicities into the language of reactive sites is an appealing theoretical challenge that could be conducive to strengthen the collaborative dialogue between experimentalists and quantum chemists. The usual schemes for such condensation, relying on atomic charges, may however lead to important information loss, due to a sometimes inappropriate averaging of the reactivity anisotropy. In this article, we present instead an approach based on the dual descriptor f, which aims at partitioning real space into nonoverlapping reactive domains that feature a constant f sign. This strategy enables not only to identify the nucleo/electrophilic regions inside a molecule but also to quantify meaningful properties (mean value, volume, electron population...). Its interest is then illustrated on two specific chemical problems: the measure of sigma-holes in the context of halogen bonds, and of the electrophilicity of organic carbocations, casting the light on the versatility of this method. (c) 2015 Wiley Periodicals, Inc.
The shooting hit rate is one of the important factors that affect the football game globally, thus how to improve the shooting hit rate becomes the key to the game. This paper reasonably estimates the various factors ...
详细信息
ISBN:
(纸本)9781845648442;9781845648435
The shooting hit rate is one of the important factors that affect the football game globally, thus how to improve the shooting hit rate becomes the key to the game. This paper reasonably estimates the various factors in shooting, uses large amounts of geometry and algebra knowledge, through grid algorithm transforms the problem into a computer C++ program, runs it and obtains a significant number of data packets, through the vertical and horizontal comparison and comprehensive analysis, finds out and discovers some principles and laws, and provides professional advice for the route of soccer dribbling, shooting, and goalkeeping link.
This article gives the algorithm of the sector in which the development coefficient is, and the steps to simultaneously calculate the development coefficient and combination coefficient of background value. Unifying t...
详细信息
This article gives the algorithm of the sector in which the development coefficient is, and the steps to simultaneously calculate the development coefficient and combination coefficient of background value. Unifying the development coefficient and the background value's coefficient of combination to optimize the model together, avoiding the malpractice to separate the two in traditional method, and avoiding the error brought out by matrix multiplication because of matrix's illness and so on in the traditional way, therefore increases the precision of the model.
In the study,structural reliability prediction based on support vector regression is *** grid algorithm is employed to choose the parameters of support vector *** Hydroelectric Power Station is employed as research ob...
详细信息
In the study,structural reliability prediction based on support vector regression is *** grid algorithm is employed to choose the parameters of support vector *** Hydroelectric Power Station is employed as research object to testify the effectiveness of the proposed SVR ***,the influencing factors of structural reliability of Jinghong Hydroelectric Power Station is ***,the comparison of the prediction results and corresponding prediction error of structural reliability between SVR and BP neural network is *** experimental results show that the prediction error of SVR is smaller than that of BP neural *** can be seen that the prediction ability for structural reliability of SVR is better than that of BP neural network.
This paper presents a genetic algorithm(GA) approach for parameters optimization of support vector machine, which is used for the object-oriented classification of high spatial resolution images over urban *** propose...
详细信息
This paper presents a genetic algorithm(GA) approach for parameters optimization of support vector machine, which is used for the object-oriented classification of high spatial resolution images over urban *** proposed method is a three-step routine involves the integration of 1) image segmentation,2) GA-based parameter optimization of Support vector machine(SVM),and 3) objected-based classification. Experiments conducted on multi-spectral Quick-Bird image fused with panchromatic image in Fuzhou *** addition,a traditional parameter searching method,grid algorithm,was investigated to evaluate the effectiveness of the proposed *** results show that our proposed GA-based approach significantly outperforms the grid algorithm both in terms of classification accuracy and time efficiency.
Empirical and mechanistic experimental design methods are combined to construct partial models, which are, thus, used to design a process. The grid algorithm restricts the next experimental point to potential process ...
详细信息
Empirical and mechanistic experimental design methods are combined to construct partial models, which are, thus, used to design a process. The grid algorithm restricts the next experimental point to potential process optima, according to the confidence intervals around the optimal points, and works with any experimental design algorithm such as D-optimal. Two case studies show the advantages of implementing the grid algorithm. On average the improvement due to the grid algorithm was 15-20% in the first case study. The second case study is based oil thin film growth using four potential models, with the most probable model used for experimental design. The grid algorithm balances the trade-off between two extremes: D-optimal designs and sampling at the predicted optimal point. The methodology presented shows that the experimenter does not have to decide ahead of time on purely empirical or mechanistic experimental design methods, since both may be useful. (c) 2008 American Institute of Chemical Engineers AIChE J, 55: 342-353, 2009
Protein structure comparison is one of the most important problems in Bioinformatics. In this paper, we develop a convex hull expression of a protein and propose a grid method to evaluate similarity between two convex...
详细信息
Protein structure comparison is one of the most important problems in Bioinformatics. In this paper, we develop a convex hull expression of a protein and propose a grid method to evaluate similarity between two convex hulls. The purpose of introducing the convex hull expression is to investigate the relationship between the surface shape similarity and the protein function similarity. Extensive numerical experiments shows that proteins in a family do have surface shape similarity and proteins in different families have their shapes in quite large difference. To explore the shape similarity of proteins in different families, we observe the possible local shape similarity by reorganizing the convex hull’s supporting plane information into a set of local shape information. And comparing the local shape information of two proteins leads us to find some local shape similarity for some pairs of proteins whose structure similarity is difficult to evaluate by traditional comparison methods. The biological meaning of local shape similarity remains unclear.
An iterative grid message-passing algorithm for model-based digital image halftoning is introduced. Based on the standard message-passing algorithm on the grid graphical model, the algorithm is designed to suboptimall...
详细信息
ISBN:
(纸本)0819448087
An iterative grid message-passing algorithm for model-based digital image halftoning is introduced. Based on the standard message-passing algorithm on the grid graphical model, the algorithm is designed to suboptimally solve general two-dimensional (2D) digital least metric (DLM) problems and is found to be very successful (i.e., nearly optimal) for 2D data detection in page-oriented optical-memory (POM) systems. In contrast to many 2D (iterative) optimization techniques, this grid algorithm attempts to achieve a globally optimal solution via a local-metric computation and message-passing scheme. Using a reduced-complexity technique, the simplified grid algorithm is proposed for the halftoning problem and is shown to provide similar image quality as compared to the best halftoning algorithms in the literature. Since the grid algorithm does not exploit the properties of a specific metric, it is directly applicable to other digital image processing tasks (e.g., optimal near-lossless coding, entropy-constrained halftoning, or image/video dependent quantization).
This paper proposes a simulated annealing algorithm for multiobjective optimizations of electromagnetic devices to find the Pareto solutions in a relatively simple manner. The algorithm is based on the successful intr...
详细信息
This paper proposes a simulated annealing algorithm for multiobjective optimizations of electromagnetic devices to find the Pareto solutions in a relatively simple manner. The algorithm is based on the successful introductions of the Pareto set as well as the parameter and objective space strings. The new rank formula and fitness-sharing function's together with the stop criterion and other improvements are investigated in the proposed method. Two numerical examples for validating the robustness of the proposed method are also reported.
暂无评论