一种基于加法链的快速标量乘算法

给出一种标量的串长加法链算法来提高椭圆曲线标量乘法的效率。新的标量乘算法结合底层域直接计算2Q+P、2^nR+S算法,使用大小窗口法将串长算法和滑动窗口算法结合,加法链长度、存储空间和预计算都减少,其效率比二元法提高53%,比NAF法提高47.5%,比串长算法提高46.2%,比Windows法提高42.2%。     

First-order side channel attacks on Zhang’s countermeasures

Zhang’s three countermeasures are known to be secure against certain first-order side channel attacks such as differential power analysis and correlation power analysis. This security comes from the countermeasures’ use of random points to blind the message and random integers to blind the secret scalar. In this paper, we propose first-order side channel attack methods that can perfectly break these three countermeasures. Even though Zhang’s countermeasures use random points and random integers our attacks are made possible by the fact that intermediate values computed by these countermeasures are dependent on specific values that we can guess. The experimental results verify that the proposed attack methods can successfully break existing countermeasures.     

Fuzzy functions with LSE

“Fuzzy Functions” are proposed to be determined by the least squares estimation (LSE) technique for the development of fuzzy system models. These functions, “Fuzzy Functions with LSE” are proposed as alternate representation and reasoning schemas to the fuzzy rule base approaches. These “Fuzzy Functions” can be more easily obtained and implemented by those who are not familiar with an in-depth knowledge of fuzzy theory. Working knowledge of a fuzzy clustering algorithm such as FCM or its variations would be sufficient to obtain membership values of input vectors. The membership values together with scalar input variables are then used by the LSE technique to determine “Fuzzy Functions” for each cluster identified by FCM. These functions are different from “Fuzzy Rule Base” approaches as well as “Fuzzy Regression” approaches. Various transformations of the membership values are included as new variables in addition to original selected scalar input variables; and at times, a logistic transformation of non-scalar original selected input variables may also be included as a new variable. A comparison of “Fuzzy Functions-LSE” with Ordinary Least Squares Estimation (OLSE)” approach show that “Fuzzy Function-LSE” provide better results in the order of 10% or better with respect to RMSE measure for both training and test cases of data sets.     

一种新型的量化方法与基于小波变换的指纹图像压缩

针对矢量量化和标量量化各有优劣的现状，一种简单，有效的新型量佛方法被提出来了。本文把应用于基于小波变换的指纹压缩，改进了ＥＢＩ的ＷＳＱ算法，大大降低了量化计算复杂度。即获得较高的压缩比，又有较好的主客观质量，并与ＪＰＥＧ标准进行了对比。     

Fuzzy logic speed controller optimization approach for induction motor drive using backtracking search algorithm

This paper presents an adaptive fuzzy logic controller (FLC) design technique for controlling an induction motor speed drive using backtracking search algorithm (BSA). This technique avoids the exhaustive traditional trial-and-error procedure for obtaining membership functions (MFs). The generated adaptive MFs are implemented in speed controller design for input and output based on the evaluation results of the fitness function formulated by the BSA. In this paper, the mean absolute error (MAE) of the rotor speed response for three phase induction motor (TIM) is used as a fitness function. An optimal BSA-based FLC (BSAF) fitness function is also employed to tune and minimize the MAE to improve the performance of the TIM in terms of changes in speed and torque. Moreover, the measurement of the real TIM parameters via three practical tests is used for simulation the TIM. Results obtained from the BSAF are compared with those obtained through gravitational search algorithm (GSA) and particle swarm optimization (PSO) to validate the developed controller. Design procedure and accuracy of the develop FLC are illustrated and investigated via simulation tests for TIM in a MATLAB/Simulink environment. Results show that the BSAF controller is better than the GSA and PSO controllers in all tested cases in terms of damping capability, and transient response under different mechanical loads and speeds.     

三角形和三角形相交测试技术研究

高效率的“三角形和三角形相交测试”对于提高碰撞检测算法效率,增强虚拟场景的真实感和沉浸感起着至关重要的作用。该文深入研究了“三角形和三角形相交测试”的基本原理和典型算法,根据算法思想提出两个概念：标量判别法和矢量判别法,并对两种算法进行验证,对仿真计算结果进行分析、比较得出：矢量判别算法是对标量判别算法的改进和优化,条件相同时检测效率提高约7％,算法更加简单快捷,具有较高的理论意义和实际工程应用价值。     

与共形不变标量场耦合的Robertson Walker几何的量子化

本文采用约束哈密顿体系的正则描述对与共形不变标量场耦合的Robertson—Walker宇宙量子化,得到了相应的Wheeler—Dewitt方程的精确解,并且证明了在这种情况下代表量子引力中算符次序模糊的参数P等于零。最后,我们还证明了宇宙标度因子的最小值为普朗克长度,从而避免了宇宙向奇点的塌缩。     

General IF-sets with triangular norms and their applications to group decision making

A concept of general IF-sets, i.e. “intuitionistic” fuzzy sets according to Atanassov, with triangular norm-based hesitation degrees is introduced and developed. That concept is used to construct flexible algorithms of group decision making which involve relative scalar cardinalities defined by means of generalized sigma counts of fuzzy sets. Two cases of group decisions, based on individual or social fuzzy preference relations, are considered.     

Efficient elliptic curve scalar multiplication algorithms resistant to power analysis

This paper presents four algorithms for securing elliptic curve scalar multiplication against power analysis. The highest-weight binary form (HBF) of scalars and randomization are applied to resist power analysis. By using a special method to recode the scalars, the proposed algorithms do not suffer from simple power analysis (SPA). With the randomization of the secret scalar or base point, three of the four algorithms are secure against differential power analysis (DPA), refined power analysis (RPA) and zero-value point attacks (ZPA). The countermeasures are also immune to the doubling attack. Fast Shamir’s method is used in order to improve the efficiency of parallel scalar multiplication. Compared with previous countermeasures, the new countermeasures achieve higher security and do not impact overall performance.