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LIMITING DIRECTIONS OF JULIA SETS OF ENTIRE SOLUTIONS TO COMPLEX DIFFERENTIAL EQUATIONS 被引量:1
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作者 王珺 陈宗煊 《Acta Mathematica Scientia》 SCIE CSCD 2017年第1期97-107,共11页
In this paper,we mainly investigate the dynamical properties of entire solutions of complex differential equations.With some conditions on coefficients,we prove that the set of common limiting directions of Julia sets... In this paper,we mainly investigate the dynamical properties of entire solutions of complex differential equations.With some conditions on coefficients,we prove that the set of common limiting directions of Julia sets of solutions,their derivatives and their primitives must have a definite range of measure. 展开更多
关键词 limiting direction Julia set entire function linear differential equation defi-ciency
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Optimality for Henig Proper Efficiency in Vector Optimization Involving Dini Set-Valued Directional Derivatives
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作者 Guolin Yu Huaipeng Bai 《Applied Mathematics》 2011年第7期922-925,共4页
This note studies the optimality conditions of vector optimization problems involving generalized convexity in locally convex spaces. Based upon the concept of Dini set-valued directional derivatives, the necessary an... This note studies the optimality conditions of vector optimization problems involving generalized convexity in locally convex spaces. Based upon the concept of Dini set-valued directional derivatives, the necessary and sufficient optimality conditions are established for Henig proper and strong minimal solutions respectively in generalized preinvex vector optimization problems. 展开更多
关键词 VECTOR Optimization Dini set-VALUED directional DERIVATIVE Generalized Preinvex Function Henig PROPER Efficiency
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Function S-Rough sets and its applications 被引量:25
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作者 Cui Yuquan Shi Kaiquan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2006年第2期331-338,共8页
Based on S-rough sets(singular rough sets), this paper presents function S-rough sets (function singular rough sets)and its mathematical structures and features. Function S-rough sets has two forms: function one ... Based on S-rough sets(singular rough sets), this paper presents function S-rough sets (function singular rough sets)and its mathematical structures and features. Function S-rough sets has two forms: function one direction S-rough sets (function one direction singular rough sets) and function two direction S-rough sets (function two direction singular rough sets). This paper advances the relationship theorem of function S-rough sets and S-rough sets. Function S-rough sets is the general form of S-rough sets, and S-rough sets is the special ease of function S-rough sets. In this paper, applications of function S-rough sets in rough law mining-discovery of system are given. Function S-rough sets is a new research direction of rough sets and rough system. 展开更多
关键词 function s-rough sets structure of function s-rough sets relationship theorem rough law mining-discovery applications.
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Function S-rough sets and mining-discovery of rough law in systems 被引量:25
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作者 Shi Kaiquan Xia Jiarong 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2006年第4期919-926,共8页
Function S-rough sets (function singular rough sets) is defined on a -function equivalence class [u]. Function S-rough sets is the extension form of S-rough sets. By using the function S-rough sets, this paper gives... Function S-rough sets (function singular rough sets) is defined on a -function equivalence class [u]. Function S-rough sets is the extension form of S-rough sets. By using the function S-rough sets, this paper gives rough law generation model of a-function equivalence class, discussion on law mining and law discovery in systems, and application of law mining and law discovery in communication system. Function S-rough sets is a new theory and method in law mining research. 展开更多
关键词 function s-rough sets structure of function s-rough sets relationship theorem rough law mining-discovery applications.
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S-rough sets and the discovery of F-hiding knowledge 被引量:2
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作者 Hao Xiumei Fu Haiyan Shi Kaiquan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2008年第6期1171-1177,共7页
Singular rough sets (S-rough sets) have three classes of forms: one-directional S-rough sets, dual of onedirectional S-rough sets, and two-directional S-rough sets. Dynamic, hereditary, mnemonic, and hiding propert... Singular rough sets (S-rough sets) have three classes of forms: one-directional S-rough sets, dual of onedirectional S-rough sets, and two-directional S-rough sets. Dynamic, hereditary, mnemonic, and hiding properties are the basic characteristics of S-rough sets. By using the S-rough sets, the concepts of f-hiding knowledge, F-hiding knowledge, hiding degree, and hiding dependence degree are given. Then, both the hiding theorem and the hiding dependence theorem of hiding knowledge are proposed. Finally, an application of hiding knowledge is discussed. 展开更多
关键词 one-direction s-rough sets f-hiding knowledge hiding degree hiding dependence degree hiding theorem hiding dependence theorem application
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JULIA LIMITING DIRECTIONS OF ENTIRE SOLUTIONS OF COMPLEX DIFFERENTIAL EQUATIONS 被引量:1
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作者 王珺 姚潇 张诚纯 《Acta Mathematica Scientia》 SCIE CSCD 2021年第4期1275-1286,共12页
For entire or meromorphic function f,a value θ∈[0,2π)is called a Julia limiting direction if there is an unbounded sequence{z_(n)}in the Julia set satisfying limn→∞ arg z_(n)=θ.Our main result is on the entire s... For entire or meromorphic function f,a value θ∈[0,2π)is called a Julia limiting direction if there is an unbounded sequence{z_(n)}in the Julia set satisfying limn→∞ arg z_(n)=θ.Our main result is on the entire solution f of P(z,f)+F(z)f^(s)=0,where P(z,f)is a differential polynomial of f with entire coefficients of growth smaller than that of the entire transcendental F,with the integer s being no more than the minimum degree of all differential monomials in P(z,f). We observe that Julia limiting directions of f partly come from the directions in which F grows quickly. 展开更多
关键词 Julia set meromorphic function Julia limiting direction complex differential equations
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CONE-DIRECTED CONTINGENT DERIVATIVES AND GENERALIZED PREINVEX SET-VALUED OPTIMIZATION 被引量:10
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作者 丘京辉 《Acta Mathematica Scientia》 SCIE CSCD 2007年第1期211-218,共8页
By using cone-directed contingent derivatives, the unified necessary and sufficient optimality conditions are given for weakly and strongly minimal elements respectively in generalized preinvex set-valued optimization.
关键词 Preinvex set-valued optimization cone-directed contingent derivative optimality conditions
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Image Filter for Removal of Impulse Noise Based on Directional Derivatives 被引量:2
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作者 KONG Tao, LI Jun-li, CHEN Gang (College of Information Science and Engineering, Ningbo University, Ningbo 315211, China) 《Computer Aided Drafting,Design and Manufacturing》 2008年第2期91-102,共12页
One of the most common image processing tasks involves the removal of noise from images. Noise can be introduced during image capture, during transmission, or during storage. For design purposes, noise sources are fre... One of the most common image processing tasks involves the removal of noise from images. Noise can be introduced during image capture, during transmission, or during storage. For design purposes, noise sources are frequently approximated by random variables with a known probability distribution. One common noise model corrupts a signal by introducing impulses. And the surface of the image disturbed by impulse noise displays many peaks or vales. According to the characteristic of impulse noise, a novel algorithm is proposed to the detection of impulse noise point from images based on directional derivatives. First, the theory of calculus on directional derivatives is introduced in detail. Then it is applied to the field of image to removing noise with the discrete form derived from its continuous mathematical model. And a number of contrasting simulations illustrate that our algorithm not only can preserve the structure information while removing impulse noise but also can mostly save the gray value of the pixels undisturbed by noise. In addition, the comparisons of the filtering performance for removing impulse noise are analyzed in detail in the case of different noise densities, and also show that the algorithm suggested outperforms the conventional filter algorithms such as mean filter, median filter and so on in speed and impulse noise reduction, especially in random-valued impulse noise reduction. So it is a very good alternative to the existing schemes. 展开更多
关键词 level sets directional derivatives impulse noise median filter
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THE REGULARITY OF RANDOM GRAPH DIRECTED SELF-SIMILAR SETS 被引量:2
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作者 ZhangXiaoqun LiuYanyan 《Acta Mathematica Scientia》 SCIE CSCD 2004年第3期485-492,共8页
A set in Rd is called regular if its Hausdorff dimension coincides with its upper box counting dimension. It is proved that a random graph-directed self-similar set is regular a.e..
关键词 Random graph-directed self-similar set Hausdorff dimension box-counting dimension REGULAR
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A NOTE ON q-DIFFERENCE OPERATOR AND RELATED LIMIT DIRECTION
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作者 李叶舟 宋宁芳 《Acta Mathematica Scientia》 SCIE CSCD 2018年第6期1678-1688,共11页
The growth of entire functions under the q-difference operators is studied inthis paper, and then some properties of Julia set of entire functions under the higher orderq-difference operators are obtained.
关键词 q-difference operator order limit direction Julia set
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Function S-rough sets and two law forecast
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作者 Fu Haiyan Shi Kaiquan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第2期332-338,共7页
Function S-rough sets has the properties of dynamics, heredity, and memory. Function S-rough sets is penetrated and crossed with the issue of economic law forecast, then a new forecast model based on function S-rough ... Function S-rough sets has the properties of dynamics, heredity, and memory. Function S-rough sets is penetrated and crossed with the issue of economic law forecast, then a new forecast model based on function S-rough sets namely the two law forecast model is proposed, which includes upper law forecast model and lower law forecast model; and its' implement algorithm is given. Finally, the validity of the model is demonstrated by the forecast for region economic development of Hainan Province. 展开更多
关键词 function s-rough sets two law forecast dynamic economic system
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A NOTE ON THE JULIA SETS OF ENTIRE SOLUTIONS TO DELAY DIFFERENTIAL EQUATIONS
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作者 李叶舟 孙合庆 《Acta Mathematica Scientia》 SCIE CSCD 2023年第1期143-155,共13页
Let f be an entire solution of the Tumura-Clunie type non-linear delay differential equation.We mainly investigate the dynamical properties of Julia sets of f,and the lower bound estimates of the measure of related li... Let f be an entire solution of the Tumura-Clunie type non-linear delay differential equation.We mainly investigate the dynamical properties of Julia sets of f,and the lower bound estimates of the measure of related limiting directions is verified. 展开更多
关键词 delay differential equation dynamical properties Julia sets limiting directions
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基于重叠网格的船舶航向稳定性数值研究
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作者 贾爱鹏 彭晓星 +1 位作者 戚建祥 吴晓红 《武汉船舶职业技术学院学报》 2024年第3期88-91,110,共5页
基于重叠网格技术,采用URANS粘性数值模拟方法,对标准船模KVLCC2裸船体的航向稳定性进行了数值预报。基于STAR-CCM+平台,采用重叠网格技术和切割体网格,根据SIMMAN2014提供的标准算例,对KVLCC2进行了斜航运动和纯艏摇运动的数值模拟,得... 基于重叠网格技术,采用URANS粘性数值模拟方法,对标准船模KVLCC2裸船体的航向稳定性进行了数值预报。基于STAR-CCM+平台,采用重叠网格技术和切割体网格,根据SIMMAN2014提供的标准算例,对KVLCC2进行了斜航运动和纯艏摇运动的数值模拟,得到了横向力和转首力矩的历时曲线,并根据操纵性数学模型推倒出水动力导数,并计算稳定性衡准数,所有计算结果同模型试验数据吻合较好,验证了采用当前处理方法预报航向稳定性的可靠性。 展开更多
关键词 重叠网格 斜航运动 纯艏摇运动 航向稳定性
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不同发酵方式对酸豇豆品质的影响
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作者 孙宇 周主贵 +7 位作者 刘健 辛明 李昌宝 冯锦清 李杰民 李天宇 叶冬青 零东宁 《中国酿造》 CAS 北大核心 2024年第2期211-215,共5页
以新鲜豇豆为原料,采用自然发酵(CK组)、接种商业菌种(CS组)、接种自筛直投式菌剂(DVS组)3种方式发酵豇豆,测定发酵过程中发酵液的总酸、pH值及发酵成熟后豇豆的盐度、亚硝酸盐、氨基酸态氮、游离氨基酸、乳酸菌数、色差、感官品质、质... 以新鲜豇豆为原料,采用自然发酵(CK组)、接种商业菌种(CS组)、接种自筛直投式菌剂(DVS组)3种方式发酵豇豆,测定发酵过程中发酵液的总酸、pH值及发酵成熟后豇豆的盐度、亚硝酸盐、氨基酸态氮、游离氨基酸、乳酸菌数、色差、感官品质、质构特性,分析发酵方式对酸豇豆品质的影响。结果表明,在发酵过程中,DVS组的总酸增长速度最快,在1~6 d均高于CS组、CK组;CS组、DVS组的pH值下降速率比CK组快,在7 d时CS组p H值最低,DVS组仅次于CS组;在发酵至第7天时,DVS组菌落总数分别比CK组、CS组高33.86%、42.31%。发酵成熟后,DVS组的盐度、亚硝酸盐、b^(*)值最低,氨基酸态氮、游离氨基酸、乳酸菌数、感官评分、硬度、粘力、胶着性、咀嚼性最高,L^(*)值、a^(*)值、弹性与其他发酵方式无显著性差异(P>0.05)。综合可知,DVS组不仅发酵启动快,且酸豇豆成品的综合品质更优。 展开更多
关键词 酸豇豆 发酵方式 直投式菌剂 品质
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直投式酵母菌发酵对江蓠腥味及膳食纤维性质的影响
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作者 木尼热·卡地尔 姚沅俊 +5 位作者 蔡真珍 蔡宁 姜泽东 郑明静 杜希萍 倪辉 《食品研究与开发》 CAS 2024年第6期23-30,共8页
海藻是重要的海洋生物资源,富含多种生物学功能的膳食纤维。传统工艺制备的海藻膳食纤维具有较强的腥味,影响其在食品中的应用。以江蓠为原料,研究直投式酵母菌发酵对江蓠腥味及其膳食纤维性质的影响。研究表明,优化得到酵母菌直投式发... 海藻是重要的海洋生物资源,富含多种生物学功能的膳食纤维。传统工艺制备的海藻膳食纤维具有较强的腥味,影响其在食品中的应用。以江蓠为原料,研究直投式酵母菌发酵对江蓠腥味及其膳食纤维性质的影响。研究表明,优化得到酵母菌直投式发酵剂发酵脱腥的温度为25℃、活化菌液稀释倍数为4、江蓠与稀释菌液比例为1∶20(g/mL)、发酵时间为4 h。发酵后,江蓠样品的腥味强度评分由2.28上升至9.67,腥味成分中的正己醛、1-辛烯-3-醇、(Z)-4-癸烯醛、(Z),(Z)-2,4-癸二烯醛含量明显下降。发酵前后,江蓠膳食纤维的持水性分别为29.20、30.50g/g、持油性分别为5.73、6.09 g/g、白度分别为1.86%和1.77%、凝胶强度分别为355、463 N·mm。综上,江蓠进行直投酵母菌发酵后,能较好地降低其腥味,且对江蓠膳食纤维的性质影响较小。 展开更多
关键词 江蓠 直投式酵母菌剂 发酵 腥味 膳食纤维
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柔性直流换流站异常监控数据实时预警研究
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作者 王林 姚发兴 +2 位作者 王健 唐力 桂辉阳 《自动化仪表》 CAS 2024年第3期70-73,82,共5页
为了提高对异常数据的预警性能、维护柔性直流换流站的运行稳定性,提出了柔性直流换流站异常监控数据实时预警方法。首先,利用经验规则消除数据碰撞问题,根据数据信息哈希函数的异常值,准确检测出其中的异常数据。然后,利用小波变换对... 为了提高对异常数据的预警性能、维护柔性直流换流站的运行稳定性,提出了柔性直流换流站异常监控数据实时预警方法。首先,利用经验规则消除数据碰撞问题,根据数据信息哈希函数的异常值,准确检测出其中的异常数据。然后,利用小波变换对异常监控数据进行预处理,并从异常数据中提取关键变量信息。最后,根据监控过程中出现异常数据的概率,设定预警阈值,再利用预警函数构建实时预警模型。试验结果表明,应用该方法后,误报率被控制在20%以下,平均绝对误差被控制在0.12以下。相比于传统方法,该方法的预警结果更有效、准确率更高。 展开更多
关键词 柔性直流换流站 监控数据 异常数据 数据碰撞 尺度参数 数据检测 阈值设定
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基于三端柔性直流的光热储能站与新能源场站功率协同控制策略
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作者 赵玲霞 王兴贵 +2 位作者 丁颖杰 李锦键 郭永吉 《电机与控制学报》 EI CSCD 北大核心 2024年第6期131-142,共12页
新能源基地大多经传统交流方式接入高压交流或直流外送通道,为解决大规模新能源经交流接入方式下并网容量小、损耗大,以及功率波动对电网稳定性影响等问题,构建了一个基于柔性直流输电并网的风电和光伏、光热储能及电网三端柔性直流系... 新能源基地大多经传统交流方式接入高压交流或直流外送通道,为解决大规模新能源经交流接入方式下并网容量小、损耗大,以及功率波动对电网稳定性影响等问题,构建了一个基于柔性直流输电并网的风电和光伏、光热储能及电网三端柔性直流系统。基于直流电压-有功功率特性,提出一种适用于该系统的站间协调控制策略,根据柔性直流输电系统的直流电压波动情况,调整光热储能机组的出力,以平抑风、光功率波动,降低其对电网的影响。针对光热储能侧换流站,采用直流电压裕度下垂混合控制策略,通过控制器参数配置,抑制控制模式切换过程中的暂态过电压,提高系统响应速度。最后,在PSCAD/EMTDC中搭建三端柔性直流系统仿真模型,验证所提控制策略的有效性。 展开更多
关键词 新能源并网 三端柔性直流输电 光热储能 功率协调控制 参数配置
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火炮远方瞄准点法误差分析研究
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作者 韩超 闫媛媛 +2 位作者 刘广生 段纬然 刘亮 《火力与指挥控制》 CSCD 北大核心 2024年第1期118-123,共6页
针对火炮方向瞄准时因周视瞄准镜与火炮回转中心不同心所造成的瞄准误差,使用几何建模方法对方向瞄准过程进行建模,并推导瞄准误差与标定点距离、装定角度和标定点位置之间的函数关系式。通过绘制和分析多组标定点距离、装定角度、标定... 针对火炮方向瞄准时因周视瞄准镜与火炮回转中心不同心所造成的瞄准误差,使用几何建模方法对方向瞄准过程进行建模,并推导瞄准误差与标定点距离、装定角度和标定点位置之间的函数关系式。通过绘制和分析多组标定点距离、装定角度、标定点位置和瞄准误差数据图像,总结减小瞄准误差的若干方法。给出了装定角度、标定距离和对应瞄准误差极值之间的多项式拟合关系式,供相关人员使用。 展开更多
关键词 方向瞄准 远方瞄准点 瞄准误差分析 标定点设置
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海量大数据定向采样有差别挖掘算法仿真
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作者 宁滔 《现代电子技术》 北大核心 2024年第9期164-168,共5页
在大数据中,不同类别之间可能存在数据分布不均衡的情况,即某些类别的数据样本数量远远少于其他类别。这种情况下,传统的采样方法无法正确反映所有类别的特征和差异。为提升大数据信息的应用性,文中研究海量大数据定向采样有差别挖掘算... 在大数据中,不同类别之间可能存在数据分布不均衡的情况,即某些类别的数据样本数量远远少于其他类别。这种情况下,传统的采样方法无法正确反映所有类别的特征和差异。为提升大数据信息的应用性,文中研究海量大数据定向采样有差别挖掘算法。以网站统一资源定位器(URL)初始化为基础,在网络上抓取网页,采集网页的超文本标记语言(HTML)数据,提取定向数据的相关链接,并将其导入URL队列。根据网络搜索策略,实施相关的数据搜索和处理。完成数据搜索后,将自动进行下一网页的URL,继续进行海量大数据定向采样。结合模糊特征匹配与检测滤波方法实现大数据定向采样过程中的抗干扰处理。采用粗糙集算法实施挖掘,利用扩展差别矩阵对大数据决策表内的值实施约简,实现海量大数据的模式分类。实验结果显示,该算法数据采集过程中的丢包率基本控制在0.2%以下,具有较高的鲁棒性。 展开更多
关键词 海量大数据 网页抓取 定向采样 滤波处理 去冗余 粗糙集 扩展差别矩阵 决策规则
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S-Rough communication and its characteristics 被引量:3
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作者 Hu Haiqing Wang Yan Shi Kaiquan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2007年第1期148-154,共7页
In view of certain defects of common rough communication, using the S-rough sets, this article presents a S-rough communication model. The S-rough communication model is the extension of the common rough communication... In view of certain defects of common rough communication, using the S-rough sets, this article presents a S-rough communication model. The S-rough communication model is the extension of the common rough communication model. S-rough communication has two kinds of forms: one-direction S-rough communication and two-direction S-rough communication. The mathematical structure and characteristics of the one-direction S-rough communication and the two-direction S-rough communication, the relationship theorem between the one-direction S-rough communication and the two-direction S-rough communication are also presented. The S-rough communication is a dynamic communication method, and it is a novel research direction in rough sets field. 展开更多
关键词 s-rough sets One-direction s-rough sets Two-direction s-rough sets One-direction s-rough communication Two-direction s-rough communication
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