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MODIFICATION OF ALGORITHM FOR SELECTED TERM OF THE INTEGER EXTENDED EUCLIDEAN MATRIX SEQUENCE
整数扩展欧几里得矩阵序列的选择项算法的修正
DING Xiuhuan,ZHANG Shugong,TAN Chang,
丁秀欢,张树功,谭畅
系统科学与数学 , 2010,
Abstract: Wang and Pan proposed an algorithm for computing a selected term of the integer extended Euclidean matrix sequence, and use it for the modular rational number reconstruction problems. The algorithm only spent nearly linear time, matching the known complexity bound for the integer gcd, which is a special case of the algorithm. In this paper, by analyzing the algorithm, we point out an error in relevant reference, then complement the properties of the matrix sequence, finally modify the algorithm.
基于euclid算法的广义猫映射构造方法及在图像置乱中的应用
李用江,李昌利,葛建华,孙志林？
计算机科学 , 2010,
Abstract: 基于欧几里得算法求乘法逆元的思想，提出了两种构造广义猫映射的简单方法。一种基于fibonacci序列，一种基于dirichlet序列；还给出了结合这两个序列的构造方法。仿真实验表明广义猫映射的变换周期是可变的并且相对于猫映射更大，从而有较好的置乱效果，这也使得它的安全性优于猫映射和fibonacci等置乱变换。在图像信息隐蔽存储与传输中，这类图像变换具有重大的应用价值，为图像置乱提供了更坚实的理论基础。
Study on Construction Methods Based on the Euclid Algorithm for Generalized Cat Map and its Application in Image Scrambling
基于Euclid算法的广义猫映射构造方法及在图像置乱中的应用
LI Yong-jiang,LI Chang-li,GE Jian-hu,SUN Zhi-lin,
李用江,李昌利,葛建华,孙志林
计算机科学 , 2010,
Abstract: Based on the idea of multiplication inverse of Euclid algorithm, two easy construction methods for generalized cat map were presented. One is based on the Fibonacci series and the other is based on the Dirichlet series. Moreover,one construction method was presented combined with these two series. Simulation experiments show that the period of generalized cat map is alterable and greater compared with that of cat map, thus they have better scrambling effect and also make them much securer than cat map and Fibonacci transform. In practice they can find great value in practice in image information hiding for storage and transmission and provide a much solider theoretical foundation for image scrambling.
基于k-ary消减的快速最大公约数算法
王广赛,曾光,韩文报,李永光
计算机应用 , 2015,
Abstract: ？最大公约数(gcd)算法中,对于输入b和c,利用sorenson的右移k-ary消减思想提出一个算法用于寻找整数x和y,使得x和y满足bx-cy在二进制表示下低比特位部分为0,即bx-cy=0(mod2e),其中e是常数正整数。利用该算法能够右移较多比特并大规模降低循环次数。再结合模算法,提出了快速gcd算法,其输入规模为n比特时最差复杂度仍然是o(n2),但最好的情况下复杂度能达到o(nlog2nloglogn)。实验数据表明,对于20万以上比特规模的输入,快速gcd算法比binarygcd算法速度快;对100万比特规模的输入,快速gcd算法速度是binarygcd算法的两倍。
基于遗传算法的压缩空气调压系统变论域模糊PID控制
Variable Domain Fuzzy PID Control for Compressed Air Pressure Regulating System Based on Genetic Algorithm  [PDF]
迭明智
Modeling and Simulation (MOS) , 2024, DOI: 10.12677/mos.2024.136589
Abstract: 面对压缩空气这样复杂的系统，使用传统的PID控制难以满足控制要求，模糊控制作为一种智能控制方式，将其与PID控制相结合可以提高控制的鲁棒性。本文采用变论域的方法对模糊控制进行改进，在模糊控制规则不变的情况下，根据偏差的变化改变基本论域的大小，从而提高控制的精度。由于模糊PID控制中的模糊控制规则的建立过于依赖经验，具有较强的不确定性，利用遗传算法对模糊控制规则进行优化，通过增加区域筛选操作对算法进行了改进，进而避免算法陷入局部最优而无法获得全局最优解。引入欧几里得距离对模糊控制规则进行分区，通过对区域筛选找出最优解区域。本文选择误差绝对值时间积分性能指标作为目标函数，利用MATLAB建立压缩空气调压系统模型，通过对控制系统进行仿真验证控制方式的可行性。仿真结果表明：与传统PID控制和模糊PID控制相比，基于遗传算法的变论域模糊PID控制对系统的跟随性能指标和抗扰性能指标都有所改善。
For the complicated system like compressed air regulating system, it is difficult to satisfy the control requirements by using traditional PID control. Fuzzy control as an intelligent control method can be combined with PID control to improve the robustness of the control. This paper adopts the method of variable domain to improve fuzzy control, which can improve the accuracy of control by changing the size of the basic domain according to the change of error while the fuzzy control rules remain unchanged. Since the establishment of fuzzy control rules in fuzzy PID control relies too much on experience and has strong uncertainty, the genetic algorithm is used to optimize the fuzzy control rules. In order to avoid the algorithm falling into the local optimum and failing to obtain the global optimum solution, we add the region screening operation to improve the algorithm by introducing Euclidean distance to partition the fuzzy control rules by screening the region to find the region where the optimum solution is located. In this paper, the absolute value of the error time integral performance index is selected as the objective function, and the compressed air regulating system is modeled by MATLAB, and the feasibility of the control method is verified by simulation of the control system. The simulation results show that compared with the traditional PID control and fuzzy PID control, the variable domain fuzzy PID control based on genetic algorithm has improved the following performance index and the anti-disturbance performance index of the system.
改进的Harris亚像素角点快速定位
何海清,黄声享
中国图象图形学报 , 2012, DOI: 10.11834/jig.20120715
Abstract: 针对Harris算法检测角点存在偏差、运算慢、像素级精度难于满足实际应用需要等问题,改进了Harris角点检测方法。该方法在Harris提取角点过程中,通过两次角点筛选,剔除非角点和伪角点,利用角点响应函数执行非极大值抑制,以局部角点响应函数最大值的像素点作为初始角点,并以该初始角点为中心,以一定半径搜索角点簇,采用最小二乘法加权角点簇与待求角点的欧几里得距离,精化初始角点坐标,从而实现Harris亚像素角点准确快速定位。实验结果表明了该方法的有效性和实用性。
基于用户评分数据的多维度电影推荐系统研究
Research on Multi-Dimensional Movie Recommendation System Based on User Rating Data  [PDF]
余振洋, 俞婷, 陈鑫磊, 肖炼
Hans Journal of Data Mining (HJDM) , 2025, DOI: 10.12677/hjdm.2025.152017
Abstract: 随着个性化推荐系统在各类应用中的广泛应用，电影推荐作为其中的典型场景，受到了越来越多的关注。推荐系统的核心任务是根据用户的历史行为数据，特别是评分数据，来为用户提供个性化的推荐。推荐效果的好坏与相似度计算方法的选择密切相关。常见的相似度计算方法包括余弦相似度、皮尔逊相似度、欧几里得距离和Jaccard相似度。每种方法有其独特的特点和适用场景，但单一使用某种相似度方法往往会受到数据特性和环境的限制，导致推荐性能的下降。本文通过系统地比较和分析这四种相似度计算方法在不同环境下的表现，探讨了它们在电影推荐中的应用效果。研究表明，在不同数据场景下(如稀疏数据、新用户、活跃用户等)，合理组合不同相似度计算方法的比例，能够克服单一方法的局限性，显著提高推荐系统的准确性和质量。通过实验验证，我们发现基于加权组合的多维度推荐方法，相较于单一相似度方法，能够在不同推荐场景中提升推荐系统的综合表现。
With the widespread adoption of personalized recommendation systems in various applications, movie recommendation as a typical scenario has attracted increasing attention. The core task of recommendation systems lies in providing personalized suggestions based on users’ historical behavioral data, particularly rating data. The effectiveness of recommendations is closely tied to the selection of similarity computation methods. Common approaches include cosine similarity, Pearson correlation, Euclidean distance, and Jaccard similarity. While each method has unique characteristics and applicable scenarios, relying solely on a single similarity measure often leads to performance degradation due to data-specific limitations and environmental constraints. This study systematically compares and analyzes the performance of these four similarity computation methods under different environmental conditions, exploring their application effectiveness in movie recommendations. The research demonstrates that rationally combining multiple similarity measures with weighted proportions can overcome the limitations of individual methods and significantly enhance recommendation accuracy and quality across diverse data scenarios (e.g., sparse data, new users, and active users). Experimental results verify that the proposed multi-dimensional recommendation method based on weighted combinations outperforms single similarity approaches in improving comprehensive system performance across various recommendation scenarios.
Approximation Algorithm for Bottleneck Steiner Tree Problem in the Euclidean Plane
Zi-Mao Li,Da-Ming Zhu,Shao-Han Ma,
计算机科学技术学报 , 2004,
Abstract: A special case of thebottleneck Steiner tree problem in the Euclidean plane was considered in this paper. The problem has applications in the design of wireless communication networks, multifacility location, VLSI routing and network routing. For the special case which requires that there should be no edge connecting any two Steiner points in the optimal solution, a 3-restricted Steiner tree can be found indicating the existence of the performance ratio √2. In this paper, the special case of the problem is proved to beNP-hard and cannot be approximated within ratio √2. First a simple polynomial time approximation algorithm with performance ratio √2 is presented. Then based on this algorithm and the existence of the 3-restricted Steiner tree, a polynomial time approximation algorithm with performance ratio—√2+∈ is proposed, for any ∈>0. Supported partially by Shandong Province Excellent Middle-Aged and Young Scientists Encouragement Fund (Grant No.03BS004) and the Ministry of Education Study Abroad Returnees Research Start-up Fund, and the National Natural Science Foundation of China (Grant No.60273032).
Improved algorithm for Harris rapid sub-pixel corners detection
改进的Harris亚像素角点快速定位
He Haiqing,Huang Shengxiang,
何海清,黄声享
中国图象图形学报 , 2012,
Abstract: An improved algorithm for Harris rapid sub-pixel corner detection is proposed by considering the limitations of inaccurate localization and the low efficiency of the Harris algorithm. The improved algorithm is used to reject non-corners and false corners by screening the corners two times. After detecting the initial corners with the non-maximum suppression of the corners response function, the initial corners are refined to sub-pixel corners by the Euclidean distance between the corner cluster and an ideal corner using a weighted least squares method. The location of the initial corners are considered as the center of the searching corner cluster, and the value of the corners response function is considered as weight. Our tests show that the improved algorithm is effective and practical.
Feature surface recognition in reverse engineering
逆向工程中特征曲面的识别方法
HE Rong,LI Ji-jun,
何荣,李际军
计算机应用 , 2007,
Abstract: An algorithm of feature surface recognition based on quadric surface fitting and geometry property was presented. Firstly, using quadric surface to fit with given surface and calculate the error metric to identify free surface and general quadric surface. Then, compute geometry property of each point on Gaussian sphere and curvature coordinate. The distribution would identify each kind of quadric surface and blend surface. In order to improve the efficiency and practicability, this algorithm calculated approximation distance from point to surface and make priority to identify planes. This algorithm is easy to recognize plane, cylinder, cone, sphere, blend surface and free surface.
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