道路网络中的连续最近邻查询

为了减少连续最近邻查询中计算K个最近邻的次数和减小算法需要的存储空间,提出一种道路网络中求连续最近邻的方法。给出分点的计算方法及连续最近邻查询算法,对算法的正确性、可终止性进行证明,并分析算法复杂度。与相关算法进行实验比较,得出该算法更适合于对象频繁发生变化的实际网络。     

基于知识点约束的遗传算法组卷策略的研究

基于遗传算法的自动组卷策略采用分段实数编码,具有自适应型的交叉和变异遗传算子,基于知识点约束的分题型的组卷算法思想,为自动组卷算法的进一步发展提供了研究方向.     

有效地设计创意点

设计是创意产业,同时也是理性的、有据可循的。通过特定的方式寻找设计的创意点,有助于设计师诞生更多的优秀的设计作品。本文通过使用者的行为分析、多功能产品、特殊人群、情感化设计等方面,结合具体的设计案例,分析这些优秀设计创意点的产生,总结出寻找有效设计创意点的方法。     

闭合B样条曲线控制点的快速求解算法及应用

为了提高求解闭合B样条曲线控制点的速度,提出了一种基于专用LU分解的求解算法。根据控制点方程组系数矩阵的特点,参照追赶法的LU分解,构造了分解后的、矩阵的结构。基于这两个矩阵的结构特征设计了专用的LU分解方法,具有较少的存储空间和计算量。在此基础上,根据追赶法的原理,设计了闭合B样条曲线控制点的快速求解算法。通过数值实验和在等值线光滑中的实际应用,表明了该算法的可靠性和有效性。     

Face recognition based on 3D ridge images obtained from range data

In this paper, we present an approach for 3D face recognition from frontal range data based on the ridge lines on the surface of the face. We use the principal curvature, k_max, to represent the face image as a 3D binary image called ridge image. The ridge image shows the locations of the ridge points around the important facial regions on the face (i.e., the eyes, the nose, and the mouth). We utilized the robust Hausdorff distance and the iterative closest points (ICP) for matching the ridge image of a given probe image to the ridge images of the facial images in the gallery. To evaluate the performance of our approach for 3D face recognition, we performed experiments on GavabDB face database (a small size database) and Face Recognition Grand Challenge V2.0 (a large size database). The results of the experiments show that the ridge lines have great capability for 3D face recognition. In addition, we found that as long as the size of the database is small, the performance of the ICP-based matching and the robust Hausdorff matching are comparable. But, when the size of the database increases, ICP-based matching outperforms the robust Hausdorff matching technique.     

Understanding developer and manager perceptions of function points and source lines of code

Although function points (FP) are considered superior to source lines of code (SLOC) for estimating software size and monitoring developer productivity, practitioners still commonly use SLOC. One reason for this is that individuals who fill different roles on a development team, such as managers and developers, may perceive the benefits of FP differently. We conducted a survey to determine whether a perception gap exists between managers and developers for FP and SLOC across several desirable properties of software measures. Results suggest managers and developers perceive the benefits of FP differently and indicate that developers better understand the benefits of using FP than managers.     

μ-Bases and singularities of rational planar curves

We provide a technique to detect the singularities of rational planar curves and to compute the correct order of each singularity including the infinitely near singularities without resorting to blow ups. Our approach employs the given parametrization of the curve and uses a μ-basis for the parametrization to construct two planar algebraic curves whose intersection points correspond to the parameters of the singularities including infinitely near singularities with proper multiplicity. This approach extends Abhyankar's method of t-resultants from planar polynomial curves to rational planar curves. We also derive the classical result that for a rational planar curve of degree n the sum of all the singularities with proper multiplicity is (n−1)(n−2)/2. Examples are provided to flesh out our results.     

An efficient image-mosaicing method based on multifeature matching

Mosaicing is connecting two or more images and making a new wide area image with no visible seam-lines. Several algorithms have been proposed to construct mosaics from image sequence where the camera motion is more or less complex. Most of these methods are based either on the interest points matching or on theoretical corner models. This paper describes a fully automated image-mosaicing method based on the regions and the Harris points primitives. Indeed, in order to limit the search window of potential homologous points, for each point of interest, regions segmentation and matching steps are being performed. This enables us to improve the reliability and the robustness of the Harris points matching process by estimating the camera motion. The main originality of the proposed system resides in the preliminary manipulation of regions matching, thus making it possible to estimate the rotation, the translation and the scale factor between two successive images of the input sequence. This estimation allows an initial alignment of the images along with the framing of the interest points search window, and therefore reducing considerably the complexity of the interest points matching algorithm. Then, the resolution of a minimization problem, altogether considering the couples of matched-points, permits us to perform the homography. In order to improve the mosaic continuity around junctions, radiometric corrections are applied. The validity of the herewith described method is illustrated by being tested on several sequences of complex and challenging images captured from real-world indoor and outdoor scenes. These simulations proved the validity of the proposed method against camera motions, illumination variations, acquirement conditions, moving objects and image noise. To determine the importance of the regions matching stage in motion estimation, as well as for the framing of the search window associated to a point of interest, we compared the matching points results of this described method with those produced using the zero-mean normalized cross correlation score (without regions matching). We made this comparison in the case of a simple motion (without the presence of a rotation around optical axis and/or a scale factor), in the case of a rotation and in the general case of an homothety. For justifying the effectiveness of this method, we proposed an objective assessment by defining a reconstruction error.

用于求解约束优化问题的自适应佳点集进化算法

提出一种用于求解约束优化问题的自适应佳点集进化算法.新算法利用佳点集原理设计多点交叉算子,该交叉算子能够根据父代个体的相似度自适应调整交叉点的位置和子代个体的数目,产生具有代表性的子代个体.在约束处理技术上,改进了Deb的三条比较准则,提出一种新的适应度函数用于比较个体优、劣的比较准则.通过对13个标准测试函数的试验比较验证了新算法的有效性和稳健性.