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Search Results: 1 - 10 of 14463 matches for " 鲁业频 "
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可选特征的快速分形图像编码
袁宗文,,杨汉生
中国图象图形学报 , 2015, DOI: 10.11834/jig.20150203
Abstract: 目的基本分形图像编码非常耗时,基于子块特征的方法在加快编码速度方面非常有效,提出了一个新的子块特征函数,加快编码速度,改善编码性能.方法首先证明了一个定理,它统一了多个文献提出的理论方法,可以对子块任意定义特征.定理阐述了特征轨迹的长度、分布与编码性能的关系,比较了多个文献算法的优劣,并在定理的基础上定义了一个新的特征.结果实验结果表明,提出的算法在编码性能上较主对角和算法和叉迹算法有一定程度的提高,在PSNR相同情况下该算法具有较短的编码时间,在编码时间相同情况下该算法具有较高的PSNR;在相同的搜索半径内,该算法可找到更多的最佳匹配块;基于子块特征的近邻只是匹配误差极小的必要而非充分条件,当搜索10%的码本容量时,该算法只有约25%的R块找到了其最佳匹配块,当搜索到一半码本容量时,这样的R块数量达到了约80%.结论提出的新子块特征算法较主对角和算法和叉迹算法改善了编码性能,提高了图像质量.
基于DCT编码的新进展
,李凤亭,朱仁义,陈兆龙
中国图象图形学报 , 2004, DOI: 10.11834/jig.20040101
Abstract: 目前,DCT编码在JPEG、MPEG、H.26x等编码标准中有着广泛的应用,但随着Shapiro关于小波的嵌入式零树小波编码以及Said等人提出的集合分裂等级树编码的成功应用,使图像及视频信号的压缩编码提高到了新阶段,这虽然对传统的DCT编码提出了挑战,然而,Xiong等人利用嵌入式DCT块变换之间直流系数(DC)的高度相关性也能获得较高的编码性能,因为对DCT后的系数进行重组,同样具有小波多分辨率图像的特性。此外,基于形状自适应DCT、区域支撑DCT以及形态DCT的提出,还有利用DCT系数实现信息隐藏、图像大小调整、模式识别等等,都将DCT功能与性能推向更高层次,使得基于常规的DCT编码有了更大的应用与发展空间。为使人们对DCT编码现状有一概略了解,在对该技术进行深入分析与研究的基础上,对该技术作了概略介绍,并对DCT编码发展进行了展望。
New Advances Based on the DCT Transforming Coding
基于DCT编码的新进展

LU Ye-ping,LI Feng-ting,ZHU Ren-yi,CHEN Zhao-long,
,李凤亭,朱仁义,陈兆龙

中国图象图形学报 , 2004,
Abstract: DCT(Discrete Cosine Transform) transforming coding has been widely used coding-standards such as JPEG,MPEG and H.26x exclusive of JPEG2000 at present. The compressing codings for image/video signals have been advanced to a new stage since the EZW(Embedded Zerotree Wavelet) had been introduced by Shapiro and the SPIHT(Set partition in hierarchical trees) applied by Said et al,which are a competitive challenge against the conventional DCT's coding. However,DCT's coefficients have a similar multiresolutional attributes after reorganization its datum like wavelet transforming. There are many excellent performances in the based-DCT such as arbitrarily shaped DCT,region support DCT and morphological representation of DCT coefficients are proposed.Digital watermarking,image resizing and pattern cognition can be done through utilizing DCT's coefficients,and so on.The capability and performance of the DCT have further been promoted to a higher phase. For instance,object-based coding for DCT is a promising technique for next-generation coding.Besides,the experiments show that MR-DCT(Morphological representation of DCT) is among the state-of-the-art DCT-based image coders reported in the literature.What mentioned above have been studied and analyzed deeply in this paper.Hereby,the future development of DCT is also conjected.
异丙氧基-异羟肟酸-氧钒(V)配合物的合成、晶体结构和量子化学研究
,韩广,金祥林,陈世荣
化学学报 , 2002,
Abstract: 以苯甲酰异羟肟酸为配体,首先合成四价氧钒化合物,以此为基础合成了标题化合物,并用元素分析,红外光谱,~1HNMR,~(13)CNMR,~(15)VNMR,电子吸收光谱等,分别对它进行了表征,其结构用单晶X射线衍射法测定,晶体属三斜晶系,P1-bar空间群,所得晶体学参数为a=1.1119(3)nm,b=1.1735(3)nm,c=0.8660(2)nm,α=96.84(1)°,β=106.93)(1)°,γ=88.97(1)°,V=1.0731(2)nm~3,D_c=1.415g/cm~3,Z=2,F(000)=478,μ=5.06cm~(-1)。采取abinitio(GTO-6-31d)方法对标题化合物的结构单元的成键情况进行了分析,讨论了化合物的稳定性、分子轨道能量、原子静电荷分布等情况。
一种基于多Agent协同的准并行遗传算法
江瑞,罗予,胡东成,司徒国
电子学报 , 2002,
Abstract: 提出了一种基于多Agent协同操作的准并行遗传算法结构.该算法由若干运行简单遗传算法的计算单元组成,每个单元也就是独立的计算Agent.算法依照资源分配向量为各单元分配不同的计算资源,并根据个体迁移矩阵驱动它们进行个体交换.从多Agent系统的观点看,资源的分配体现了算法对各Agent的协调,个体的迁移则体现了Agent之间的协作.该算法很容易在串行计算机上实现,此时各个计算单元具有微观上串行、宏观上并行的准并行关系.对二维准并行算法动态性能的分析表明:由于统筹考虑了各计算单元间的协同关系,算法能够更充分有效地利用有限的计算资源,在解决不同的优化问题时表现出了很高的性能.
四吡啶[3,2-a:2′,3′-c:3″,2″-h:2"',3"'-j]吩嗪的钴、镍双核配合物的合成、表征及光谱学性质研究
宋宇飞?,,韩广
无机化学学报 , 2001,
Abstract: 为了提高产率,以5,6-二胺-1,10-邻菲咯啉与1,10-邻菲咯啉-5,6-二酮反应,合成了配体四吡啶[3,2-a:2′,3′-c:3″,2″-h:2"',3"'-j]吩嗪(tpphz)。以此配体为桥合成了钴(ⅲ)、镍(ⅱ)为中心金属的三种新的双核配合物。用元素分析、红外光谱、质子核磁共振、热重分析、中心金属滴定等手段对配合物进行了结构表征,并研究了其紫外和荧光光谱性质。
一类时滞Hopfield神经网络系统的全局指数稳定
,张继,杨翊仁
电子学报 , 2002,
Abstract: 研究一类时滞Hopfield神经网络系统的平衡状态全局指数稳定性.在放宽对激励函数的可微性与单调性要求的前提下,利用矩阵理论构造适当的李雅普诺夫泛函,得到系统全局指数稳定的充分条件.
厂房下柱在垂直动载下的力学响应及稳定性
Mechanical Response and Stability of the Lower Columnof Mill Buildings under Vertical Dynamic Load

,周一一
- , 2018, DOI: 10.3969/j.issn.1000-0844.2018.05.904
Abstract: 针对单层厂房桥式吊车起吊重物时对排架下柱造成冲击的现状,基于振动力学理论,分析垂直动载环境下吊车梁及下柱体组合体系的振动特征,得到下柱垂直位移的动态响应数学表达式,显示振动位移出现两次突增,其中第一次突增伴随位移方向的突跃性改变,成为下柱的最剧烈振动,整个振动持续时间约5.5 s。结合具体算例探索相关因素对下柱位移的影响规律,发现增大柱体材质的粘滞系数、弹性模量以及动载衰减系数,可缩短振动时间、降低位移振幅、推迟乃至消除二次位移峰值;而增大起吊重量对振动时间不产生影响,但会使振幅显著增加。在此基础上,以垂直动载对振动系统作功为势函数,采用尖点突变理论建立下柱稳定性状态的判别式,并结合示例阐明通过判别式预测系统稳定时任一参量的方法。
When bridge cranes lift heavy weights, the load is borne by the lower column of single-storey mill buildings. In view of this fact, the mathematical expression of dynamic response of the lower column's vertical displacement was deduced by analyzing the vibration characteristics of the system composed of the crane beam and lower column under vertical dynamic load. The mathematical expression based on the theory of vibration mechanics showed that the vibration lasts about 5.5 s and that the vertical vibration displacement has two sudden increases. The first sudden increase of displacement is the most severe vibration of the lower column. By specific example, several factors influencing the vibration were researched. The results showed that if we increased the viscosity coefficient and elastic modulus of column material and the attenuation coefficient of dynamic load, then the vibration time is shortened, the displacement amplitude is reduced, and the peak of the second displacement is postponed or eliminated altogether. Increasing the lifting weight had no effect on the vibration duration, but did increase the amplitude significantly. On this basis, taking the work of vertical dynamic load as the potential function, the cusp catastrophe theory was used to establish the discriminant formula of the stability state of the lower column, and the method of predicting any parameter in the stable system is illustrated.
广东省玩具涂漆层可溶性铅含量调查
徐浩锋,许小,聂少萍,陈玮,
中国公共卫生 , 2001, DOI: 10.11847/zgggws2001-17-06-02
Abstract: ?近年来,不断有报道由于玩具引起损害儿童少年健康的事件,本调查从另一方面探讨了儿童少年经常接触的儿童玩具的可溶性铅含量及涂漆层脱色试验.1997年3~4月在对本省范围内抽检了3个城市8个玩具生产企业和销售单位的样本进行可溶性铅含量检测,并参照中华人民共和国的国家标准进行评价.
基于循环投影统计的数学公式自动定位方法
Mathematical Formula Automatic Location Method Based on Circular Projection Statistics
 [PDF]

彭晓阳, 毛建
Journal of Image and Signal Processing (JISP) , 2013, DOI: 10.12677/JISP.2013.23006
Abstract: 数学公式自动识别的第一步就是数学公式定位,只有从文档图像里正确定位出公式,后续的步骤如公式符号识别、公式版面分析、公式语义分析才能进行。本文根据中文文字特性,设计了一种基于循环投影统计的数学公式定位方法,该方法首先通过投影来统计关键信息,然后提取出可疑行,最后通过一系列条件进行可疑行的确认。实验结果表明本文提出的方法在计算成本非常低的前提下能保证结果的正确性。
The location of mathematical formulas is the first step to recognize mathematical formula. Only when the formula in the document image is located correctly, one can complete the following steps such as formula symbol recognition, formula document analysis and formula semantic analysis. According to the characteristics of Chinese characters, this paper presents a method for automatic extraction of mathematical formula based on circular projection statistics. This method firstly collects key information through projection, and then extracts the potential line. Finally, mathematical formulas are extracted using a series of constraint conditions. The experimental results show that the method proposed in this work offers correctness of the results at very low computational costs.
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