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1.
本文中我们首先对无约束条件时的有限时间区间上时变系统线性二次型(FH-LQ)问题进行了分类,并给出了问题恪地每一类的充分必要条件(定理2),其次证明了对于FH-LQ问题其下确介有限与其可达是等价的(定理1),在此基础上给出了问题为正则的 新的条件(定理3),最后,我们通过新的途径讨论了途径讨论了有控制能量约束时的FH-LQ问题。  相似文献   

2.
以丙烯酸二甲氨基乙酯(DLA)、马来酸酐(MA)、对苯乙烯磺酸钠(SS)等为原料,以K2S2O8为引发剂,通过水相聚合,季铵化反应后合成含烷基、羧基和磺酸基的三元共聚物阻垢剂P(MA-SS-DLA)。探讨了共聚物的投加量、钙离子质量浓度和溶液pH值等因素与共聚物阻垢率的关系以及杀菌性能,并用扫描电镜观测了碳酸钙晶形的变化,采用量子化学方法研究了共聚物P(MA-SS-DLA)对碳酸钙的阻垢性能和结构之间的关系。结果表明,共聚物适宜在Ca2+质量浓度为小于600 mg·L-1的中性循环水中使用;当聚合物投加量为16mg·L-1,杀菌12 h后,P(MA-SS-DA)杀菌率还保持73%。  相似文献   

3.
支持向量机用于胍类化合物Na/H交换抑制活性的模式识别   总被引:2,自引:0,他引:2  
将Vapnik提出的支持向量机(support vector machine,简称SVM)算法用于化合物活性的模式识别研究。SVM算法是特别适合于用有限已知样本训练建模,进而预报未知样本属性的模式识别新算法,将其用于N-(3-氧-3,4-双氢-2氢-苯并[1,4]恶嗪-6-羟基)胍类化合物的Na/H交换抑制活性类别的识别研究,用留一法考察了SVM模型的预报能力,并与Fisher判别矢量法和最近邻(KNN)法的分类预报结果进行比较,结果表明:SVM算法的预报结果优于Fisher法和KNN法的结果,因此,SVM算法可望应用于药物的构效关系研究领域。  相似文献   

4.
用逐步回归分析、主成分回归、偏最小二乘、人工神经网络这四种方法处理谷物的傅里叶变换近红外漫反射光谱,对谷物中含量在10(-1)-10(-3)的八种成分作了定量测定,其结果与经典化学方法没有系统偏差.文中还对这四种方法在谷物成分的定量测定方面的应用进行了讨论.  相似文献   

5.
本文对C^++中的++(--)运算符的重载进行了深入研究,对于有序可数的离散事件,提出了一套应用++(--)运算符求后继的方法,以素数和Ackermann函数为例,探讨了++(--)运算符的前缀形式和后缀形式的重载技巧,并给出了类定义实例。  相似文献   

6.
用静电涂布法将Nafion修饰到电化学处理后的碳纤维电极上,修饰后的电极具有一定的灵敏度和很好的选择性,在活体分析中阻断了抗坏血酸(AA),二羟基苯乙酸(DOPAC)、5-羟吲哚乙酸(5-HIAA),尿酸(UA)及高香草酸(HVA)等阴离子性化合物的干扰,直接检测了神经递质多巴胺(DA)的氧化电流,脑部微区注射试验和药物注射的药理功能都充分证明了电极的可靠性,这种处理和修饰电极的方法十分简单,无需  相似文献   

7.
差分-代数攻击是一种新的攻击方法,此方法结合了差分分析和代数攻击的思想。差分分析和代数攻击都是对高级加密标准(AES)最有效的攻击算法之一。对差分-代数如何在AES中应用进行了分析,并成功地应用此方法对5轮AES-256进行了攻击,使之比穷尽攻击更有效。  相似文献   

8.
测定了a-萘酚、a-萘胺、2,7-二羟基萘、2,4-二甲氧基苯甲醛和水杨酸甲酯五种芳香化合物的紫外光谱,用目标因子分析方法直接对混合体系紫外光谱数据进行处理,成功地确定了混合体系的物种数、物种种类以及各物种的含量。  相似文献   

9.
将3-羟基-4′-N,N-二甲氨酸黄酮甲基丙烯酸酯与甲基丙烯酸甲酯和丙烯酸丁酯共聚,制备了量种含有荧光基团的高聚物(PFMB)。基于Fe(Ⅲ)与C1^-形成的配合物对PFMB光极膜荧光的猝灭作用,研制了一种荧光光经行传感器。该传感器用于0.1 ̄6.0mol·L^-1盐酸的测量,显示了良好的重现性和可逆性,响应时间和恢复时间均小于40秒。由于荧光基团是共价固定在聚合物上,该传感器还具有较长的使用寿命  相似文献   

10.
本试验采用玉米大斑病菌2号小种产生的粗毒素和标准毒素(5-羟甲基-2-呋喃甲醛)进行玉米幼苗滴心处理,测定玉米大斑病菌HT-毒素处理后玉米叶片中木质素含量的变化。结果表明:毒素处理后属于亲和组合的玉米自交系木质素含量都有一定程度的提高,且处理后48h表现更为明显;非亲和组合的玉米自交系木质素含量变化不大,不同组合中木质素含量变化差异的原因尚需进一步研究。  相似文献   

11.
This paper addresses a novel approach to investigate, study and simulate computation of high band (HB) feature extraction based on linear predictive coding (LPC) and mel frequency cepstral coefficient (MFCC) techniques. Further, HB features are embedded into encoded bitstream of proposed global system for mobile (GSM) full rate (FR) 06.10 coder using joint source coding and data hiding before being transmitted to receiving terminal. At receiver, HB features are extracted to reproduce HB portion of speech and for the same different extension of excitation techniques are applied and their results evaluated in terms of quality (intelligibility and naturalness) and bandwidth. MATLAB based e-test bench is created for implementing the proposed artificial bandwidth extension (ABE) coder following series of simulations, that are carried out to discover and gain insight about the performance of it using subjective [mean opinion score (MOS)] and objective [perceptual evaluation of speech quality (PESQ)] analysis. The results obtained for both the analyses advocate that proposed ABE coder outperforms proposed GSM FR NB (legacy GSM FR) coder. While the fact remains that, compared to LPC based parameterizations over ABE coder, MFCC parameterization results in higher speech intelligibility which is evident from obtained slightly better PESQ and MOS scores.  相似文献   

12.
In this paper, we make an application of the harmonic balance (HB) analysis technique for studying oscillations in neural-network-based control systems where the closed-loop system can be transformed into a linear and a feedback nonlinear part (Luré regulator problem). The main goal of the present paper is to establish a test for the stability of limit cycles arising from a neural-network-control-based scheme operating over continuous nonlinear plants. The HB technique has been applied to the stability analysis of a quasilinearised nonlinear DC motor drive. The simple geometric interpretation of this technique contrasts other stability analysis techniques, such as Lyapunov, Input/Output, etc.  相似文献   

13.
Since optical and microwave sensors respond to very different target characteristics, their role in crop monitoring can be viewed as complementary. In particular, the all‐weather capability of Synthetic Aperture Radar (SAR) sensors can ensure that data gaps that often exist during monitoring with optical sensors are filled. There were three Landsat Thematic Mapper (TM) satellite images and three Envisat Advanced Synthetic Aperture Radar (ASAR) satellite images acquired from reviving stage to milking stage of winter wheat. These data were successfully used to monitor crop condition and forecast grain yield and protein content. Results from this study indicated that both multi‐temporal Envisat ASAR and Landsat TM imagery could provide accurate information about crop conditions. First, bivariate correlation results based on the linear regression of crop variables against backscatter suggested that the sensitivity of ASAR C‐HH backscatter image to crop or soil condition variation depends on growth stage and time of image acquisition. At the reviving stage, crop variables, such as biomass, Leaf Area Index (LAI) and plant water content (PWC), were significantly positively correlated with C‐HH backscatter (r = 0.65, 0.67 and 0.70, respectively), and soil water content at 5 cm, 10 cm and 20 cm depths were correlated significantly with C‐VV backscatter (r = 0.44, 0.49 and 0.46, respectively). At booting stage, only a significant and negative correlation was observed between biomass and C‐HH backscatter (r = ?0.44), and a saturation of the SAR signal to canopy LAI could explain the poor correlation between crop variables and C‐HH backscatter. Furthermore, C‐HH backscatter was correlated significantly with soil water content at booting and milking stage. Compared with ASAR backscatter data, the multi‐spectral Landsat TM images were more sensitive to crop variables. Secondly, a significant and negative correlation between grain yield and ASAR C‐HH & C‐VV backscatter at winter wheat booting stage was observed (r = ?0.73 and ?0.55, respectively) and a yield prediction model with a correlation coefficient of 0.91 was built based on the Normalized Difference Water Index (NDWI) data from Landsat TM on 17 April and ASAR C‐HH backscatter on 27 April. Finally, grain protein content was found to be correlated significantly with ASAR C‐HH backscatter at milking stage (r = ?0.61) and with Structure Insensitive Pigment Index (SIPI) data from Landsat TM at grain‐filling stage (r = 0.53), and a grain protein content prediction model with a correlation coefficient of 0.75 was built based on the C‐HH backscatter and SIPI data.  相似文献   

14.
In this paper, we present an adaptive version of the parallel Distributive Join (DJ) algorithm that we proposed in [5]. The adaptive parallel DJ algorithm can handle the data skew in operand relations efficiently. We implemented the original and adaptive parallel DJ algorithms on a network of Alpha workstations using the Parallel Virtual Machine (PVM). We analyzed the performance of the algorithms, and compared it with that of the parallel Hybrid-Hash (HH) join algorithms. Our results show that the parallel DJ algorithms perform comparably with the parallel HH join algorithms over the entire range of the number of processors used and for different join selectivities. A significant advantage of the parallel DJ algorithms is that they can easily support non-equijoin operations.  相似文献   

15.
We study the parameters of bent and hyper-bent (HB) functions in n variables over a field $ P = \mathbb{F}_q We study the parameters of bent and hyper-bent (HB) functions in n variables over a field with q = 2 elements, ℓ > 1. Any such function is identified with a function F: QP, where . The latter has a reduced trace representation F = tr P Q (Φ), where Φ(x) is a uniquely defined polynomial of a special type. It is shown that the most accurate generalization of results on parameters of bent functions from the case ℓ = 1 to the case ℓ > 1 is obtained if instead of the nonlinearity degree of a function one considers its binary nonlinearity index (in the case ℓ = 1 these parameters coincide). We construct a class of HB functions that generalize binary HB functions found in [1]; we indicate a set of parameters q and n for which there are no other HB functions. We introduce the notion of the period of a function and establish a relation between periods of (hyper-)bent functions and their frequency characteristics. Original Russian Text ? A.S. Kuz’min, V.T. Markov, A.A. Nechaev, V.A. Shishkin, A.B. Shishkov, 2008, published in Problemy Peredachi Informatsii, 2008, Vol. 44, No. 1, pp. 15–37. Supported in part by the Russian Foundation for Basic Research, project nos. 05-01-01018 and 05-01-01048, and the President of the Russian Federation Council for State Support of Leading Scientific Schools, project nos. NSh-8564.2006.10 and NSh-5666.2006.1. A part of the results were obtained in the course of research in the Cryptography Academy of the Russian Federation.  相似文献   

16.
《国际计算机数学杂志》2012,89(3-4):171-188
The node-visit optimal (NVO) and the space-cost optimal (SCO) height-balanced (HB) 2-3 brother trees are defined. The characterization of the NVO HB 2-3 brother trees is developed. This characterization leads to a linear-time algorithm for constructing an NVO HB 2-3 brother tree for an ordered set of keys. The minimum space-cost of an N-key NVO HB2-3 brother tree and the space-cost of an N-key SCO HB 2-3 brother tree is analysed. It is shown that the minimum space-cost of an NVO HB 2-3 brother tree is never more than one plus the space-cost of an SCO HB 2-3 brother tree. Further, the minimum node-visit cost of an SCO HB 2-3 brother tree is at most one plus the node-visit cost of an NVO HB 2-3 brother tree. It is also shown that there exists an HB 2-3 brother tree which is both SCO and NVO for just over half the possible values of keys. Finally, an outline for constructing an SCO HB 2-3 brother tree is presented.  相似文献   

17.
基于BitTorrent种子的内容分发算法   总被引:1,自引:0,他引:1  
分析当前最流行的P2P软件——BT的工作方式,发现其内容分发算法使得文件片段在网络节点中分布不均,影响系统效率。提出基于种子控制的内容分发算法,该算法能有效避免稀有片段的产生,使各节点上的片段拥有量基本相等。采用单次分发时间、节点上内容相异性和平均下载时间等几个方面对新旧系统进行评估比较。仿真试验结果表明,加入新算法的系统降低了平均下载时间,提高系统的健壮性和整体效率。  相似文献   

18.
Foster的删除HB(k)树的结点的算法的主要思想是先删除结点再自下而上处理某些子树,涉及自下而上的后退。提出一种新的删除HB(k)树的结点的算法,其主要思想是先自上而下处理某些子树再删除结点,不涉及自下而上的后退。举例说明新算法的执行过程。证明新算法是正确的。与Foster的删除HB(k)树的结点的算法相比,新算法不涉及辅助栈的使用。设n是HB(k)树的结点的个数。新算法的时间复杂性是O(log2n),与Foster的删除HB(k)树的结点的算法的相同。实验结果表明新算法的平均执行时间比Foster的删除HB(k)树的结点的算法短。新算法的空间复杂性是O(1),比Foster的删除HB(k)树的结点的算法低。  相似文献   

19.
The paper presents results for spectral and textural analysis of the rock units in Landsat Thematic Mapper (TM) images, dual-band (L and C) and dual-polarization (HH and HV) Shuttle Imaging Radar (SIR)-C images, and C-band HH polarization Standard Beam 4 and Extended High Incidence Beam 3 Radarsat images from a study area between California and Arizona, USA. Fractal dimension, lacunarity and grey-level co-occurrence matrix (GLCM) textural feature images were created from the SIR-C and Radarsat images. Fractal dimensions were calculated using a differential box counting method and lacunarity measures were obtained using a new grey-scale lacunarity estimation method for 36 sample images extracted from the SIR-C and Radarsat images. The fractal dimension and lacunarity curves and class signature separability analysis show that, for rock unit discrimination using image textural features in the study area, the SIR-C L-HH image is more suitable than other SIR-C images and Radarsat images, and that co-polarization (HH) generally provides more textural information than cross-polarization (HV) in the study area. The study also shows that lacunarity measures can reveal the scaling properties of radar image textures for rock units. The combination of spectral information from Landsat TM images and textural information from radar images improves the image classification accuracy of rock units in the study area.  相似文献   

20.
Neural Networks (NN), which interconnection matrix is the Hebb matrix of Hopfield (HH) [2,3] are considered. Quasi-continuos sets of neuron states are being used for network matrix production. It is shown, that in this case minima of Hopfield energy are at the bottom of deep ditches, corresponding to the basic set of network activity states for the HH NN. The corresponding states can be made to be stable states of the network. When neuron threshold fatigue is introduced, depending of its recent activity state, the network activity becomes cyclic, moving with a constant rate in one of the two possible directions in the ring, depending on the initial conditions. The phenomena described present novel robust types of NN behavior, which have a high probability to be encountered in living neural systems.  相似文献   

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