基于BDD的增量启发式搜索方法及其应用

增量启发式搜索是一种利用先前的搜索信息和启发信息提高本次搜索效率的方法，通常可用来解决动态环境下的重规划问题。在人工智能领域，一些实时系统常常需要根据外界环境的变化不断修正自身，这样就会产生一系列变化较小的相似问题，此时应用增量启发式搜索将会非常有效。另一方面，基于BDD的强大的搜索技术利用BDD有效操作性以及化简后唯一性的优点， 在一定程度上缓解了模型检测的状态爆炸问题，使得被检测状态的个数大大增加。 1、本文结合基于BDD的启发式搜索和基于BDD的增量搜索这两种方法给出了基于BDD的增量启发式搜索方法， 基于BDD的增量启发式搜索综合了基于BDD的搜索、增量搜索以及启发式搜索这三种方法的优点。它既用BDD作为数据结构以提高搜索的空间效率， 又结合了增量搜索的思想来提高重搜索的效率，同时，又引入了启发函数来进一步压缩搜索空间。 2、本文介绍了基于BDD的增量启发式搜索算法BDDRPA*并用大量的实验结果证明BDDRPA*的高效性。给定一个搜索问题， BDDRPA*算法先用基于BDD的启发式搜索方法搜出一条从初始节点到目标节点的最短路径；接着， 问题的状态格局发生改变，BDDRPA*再用基于BDD的增量搜索方法根据旧格局的迁移关系BDD_T构造出新格局的迁移关系BDD_{T'}， 然后再用启发式方法搜索路径，如此反复下去。 3、本文介绍了基于BDD的动态增量启发式搜索算法BDDD*并用大量的实验结果证明BDDD*的高效性。 BDDD*算法在机器人边走边扫描的过程中，不断根据机器人新获得的信息更新已知地图并重新规划路线。每次规划时，BDDD*都假设未知的领域没有任何障碍物， 也就是每个位置都是可通的，它按照这个假设去计算从当前位置到目标位置的最短路径。如果在行走的过程中扫描到了障碍物，它就把这条信息添加到它的地图中，然后重复 上面的过程，直到到达目标位置或者发现每条路径都被堵死为止。 BDDRPA*算法和BDDD*算法可以应用到机器人线路规划、智能交通及计算机网络的线路规划问题中。 另外，在机器学习和控制领域，也可以考虑使用BDDRPA*算法和BDDD*算法。

Fruit anatomy,seed germination and seedling development in the Japanese seagrass phyllospadix

Phyllospadix iwatensis Makino and phyllospadix japonicus Makino have similar frunt morphology and anatomy.The rhomboid fruit of Japanese phyllospadix is dark brown in colour and is characterized by two arms bearing stiff inflected bristles which can act as an anchoring system. The fruit covering consists of a thin cuticular seed coat and pericarp remains mainly fibrous endocarp. In the groove region of the fruit.the cuticular seed coat and endocarp are replaced by nucellus cells with wall in growths and crushed pigment strands with lignified walls.these tissues appera to control the transfer of nutrients to developing seed.the seed is oval with a small embryo and a large hypocotyl. the embryo is straight and simple,with the plumule containing three leaf primordia and a pair of root primordia surrounded by a cotyledon.the hypocotyl has large vontral lobe containing central provascular tissue and two small dorsal lobes.the hypocotyl contains starch.lipid and protein.and acts as a nutrient store.the seed of P.iwatensis has a dormancy period of 2-6 weeks and germination eventually reaches-65%.but is not synchronized.during germination the leaves emerge first.and then after at least three young leaves have formed and abseised.the roots emerge,usually?6 months after the commencement of germination.Utilizaton of the nutrient reserves is initially from the perihpery of the hypocotyl and then progressively towards its centre.

Fabrication of integrated microelectrodes for electrochemical detection on electrophoresis microchip by electroless deposition and micromolding in capillary technique

A new method for the fabrication of an integrated microelectrode for electrochemical detection (ECD) on an electrophoresis microchip is described. The pattern of the microelectrode was directly made on the surface of a microscope slide through an electroless deposition procedure. The surface of the slide was first selectively coated with a thin layer of sodium silicate through a micromolding in capillary technique provided by a poly(dimethylsiloxane) (PDMS) microchannel; this left a rough patterned area for the anchoring of catalytic particles. A metal layer was deposited on the pattern guided by these catalytic particles and was used as the working electrode. Factors influencing the fabrication procedure were discussed. The whole chip was built by reversibly sealing the slide to another PDMS layer with electrophoresis microchannels at room temperature. This approach eliminates the need of clean room facilities and expensive apparatus such as for vacuum deposition or sputtering and makes it possible to produce patterned electrodes suitable for ECD on microchip under ordinary chemistry laboratory conditions. Also once the micropattern is ready, it allows the researchers to rebuild the electrode in a short period of time when an electrode failure occurs. Copper and gold microelectrodes were fabricated by this technique. Glucose, dopamine, and catechol as model analytes were tested.

Discrete wavelets transform for signal denoising in capillary electrophoresis with electrochemiluminescence detection

Discrete wavelets transform (DWT). was applied to noise on removal capillary electrophoresis-electrochemiluminescence (CE-ECL) electropherograms. Several typical wavelet transforms, including Haar, Daublets, Coiflets, and Symmlets, were evaluated. Four types of determining threshold methods, fixed form threshold, rigorous Stein's unbiased estimate of risk (rigorous SURE), heuristic SURE and minimax, combined with hard and soft thresholding methods were compared. The denoising study on synthetic signals showed that wave Symmlet 4 with a level decomposition of 5 and the thresholding method of heuristic SURE-hard provide the optimum denoising strategy. Using this strategy, the noise on CE-ECL electropherograms could be removed adequately. Compared with the Savitzky-Golay and Fourier transform denoising methods, DWT is an efficient method for noise removal with a better preservation of the shape of peaks.

Covalent grafting of luminescent rare earth complex onto MCM-41 by postsynthesis

New luminescent hybrid mesoporous material was prepared by covalent anchoring rare earth complex onto MCM-41 by a postsynthesis approach. The monomer (referred to here as PABI) which plays double roles, i.e., as a ligand for lanthanide ion and as an organic functional molecule to modify MCM-41 is synthesized and characterized by H-1 NMR and MS. The fluorescence spectra show clearly that the hybrid mesoporous material possesses excellent luminescence characteristics. The hybrid mesoporous material retains the structure of MCM-41 after modification.

Covalent modification of a glassy carbon surface by 4-aminobenzoic acid and its application in fabrication of a polyoxometalates-consisting monolayer and multilayer films

4-Aminobenzoic acid (4-ABA) was covalently grafted on a glassy carbon electrode (GCE) by amine cation radical formation in the electrooxidation process of the amino-containing compound. X-ray photoelectron spectroscopy measurement proves the presence of 4-carboxylphenylamine monolayer on the GCE. The redox responses of various electroactive probes were investigated on the 4-ABA-modified GCE. Electron transfer to Fe(CN)(6)(3-) in solutions of various pHs was studied by both cyclic voltammetry and electrochemical impedance analysis on the modified electrode. Changes in the solution pH value result in the variation of the terminal group charge state, based on which surface pK(a) values are estimated. The 4-ABA-modified GCE was used as a suitable charged substrate to fabricate polyoxometalates-consisting (POM-consisting) monolayer and multilayer films through layer-by-layer assembly based on electrostatic attraction. Cyclic voltammetry shows the uniform growth of these three-dimensional multilayer films. Taking K10H3[Pr-(SiMo7W4O39)(2)]. H2O (abbreviated as Pr(SiMo7W4)(2)), for example, the preparation and electrochemical behavior of its monolayer and multilayer film had been investigated in detail. This modification strategy is proven to be a general one suitable for anchoring many kinds of POMs on the 4-ABA-modified GCE.

Molecular evidence for the sister relationship of the eastern Asia-North American intercontinental species pair in the Podophyllum group (Berberidaceae)

The presumed pair relationships of intercontinental vicariad species in the Podophyllum group (Sinopodophyllum hexandrum vs. Podophyllum pelatum and Diphylleia grayi vs. D. cymosa) were recently, considered to be paraphyletic. In the present paper, the trnL-F and ITS gene sequences of the representatives were used to examine the sister relationships of these two vicariad species. A heuristic parsimony analysis based on the trnLF data identified Diphylleia as the basal clade of the other three genera, but provided poor resolution of their inter-relationships. High sequence divergence was found in the ITS data. ITS1 region, more variable but parsimonyuninformative. has no phylogenetic value, Sequence divergence of the ITS2 region provided abundant, phylogenetically informative variable characters. Analysis of ITS2 sequences confirmeda sister relationship between the presumable vicariad species, in spite of a low bootstrap support for Sinopodophyllum hexandrum vs. Podophyllum pelatum. The combined ITS2 and trnL-F data enforced a sister relationship between Sinopodophyllum hexandrum and Podophyllum pelatum with an elevated bootstrap support of 100%. Based on molecular phylogeny, the morphological evolution of this group was discussed. The self-pollination might have evolved from cross-fertilization two times in this group. The different pollination and seed dispersal systems of Sinopodophyllum hexandrum and Podophlyllum pelatum resulted from their adaptations to different ecological habitats. The divergence time of Sinopodophyllum hexandrum-Podophyllum pelatum is estimated to be 6.52+/-1.89 myr based on the ITS divergence. The divergence of this species pair predated or co-occurred with the recent uplift of the Himalayas 4-3 myr during the late Miocene and the formation of the alpine habitats. Sinopodophyllum hexandrum developed a host of specialized characters in its subsequent adaptation to the arid alpine surroundings. The present study confirmed the different patterns of species relationship between Asian-North American disjuncts. The isolation of plant elements between North America and eastern Asia must have been a gradual process, resulting in the different phylogenetic patterns and divergence times of the disjuncts.

无线传感器网络中一种启发式最小连通支配集算法

针对最小连通配集问题设计了一种具有较高能量效率的启发式算法。算法首先把网络中所有的节点作为最小连通支配集的一个初始解,然后利用启发式修剪策略剔除冗余节点从而减小最小连通支配集的大小,直到没有冗余节点存在。文中将算法分成集中式和分布式两种情况进行了详细讨论。仿真结果表明,由于实现简便,该算法与其他已有算法相比较,在算法复杂性和算法稳定运行时间上有一定的优势。

基于粗糙集和多Agent系统的知识挖掘

通过优化知识表达系统中条件属性对决策属性的依赖度,深入研究了粗糙集并与多Agent系统相结合。利用离散粒子群算法,提出一种基于粒子群优化的粗糙集知识约简算法,该算法解决了启发式算法无法全局搜索进行约简的问题。最后通过在矿井中调度信息的应用验证了有效性。

基于启发式节点增强策略的PRM路径规划方法

针对一般的PRM方法用于移动机器人对复杂地形路径搜索存在的缺陷 ,本文对PRM方法进行了改进 ,提出了一套基于启发式的节点增强的策略 ,提高了PRM方法节点增强阶段对环境的适应性 .此外 ,本文建立了相应的仿真实验系统对策略的有效性进行了实验与分析

港口业船舶优化调度模型设计

以港口船舶计划调度为研究背景 ,分析了港口业计划调度的特征 ,提出了生产计划调度的系统框架 ,并在此基础上建立了以船舶拖期惩罚费用为最小 ,多种因素约束下的调度模型 ,将人工智能技术应用到实际生产调度中 ,实现分层次、分级研究多种资源约束条件下的计划调度和优化

一个用于机器人自然语言理解的英语句法分析系统

在低挡微机中速度较慢的串行处理硬设备条件下，利用本文提出的启发式概念，分层搜索和匹配策略以及设置最大搜索长度等方法，可使推理速度提高一个数量级以上．此外，通过引入语义信息，分阶段消除歧义，自顶向下与自底向上相结合，以及把一般疑问句一律变成相应陈述句的方法，解决了自动英语句法分析中的一系列难题，缩小了知识库的规模。

考虑负荷的制造单元划分方法

制造单元的划分是实施单元化生产的关键途径。本文提出了一种基于工件制造工艺的并考虑机床负荷的单元划分算法。首先根据工件的加工特征及机床负荷定义了同类实体之间相似性。然后根据启发式规则选择工件族及制造单元的种子元素,并以聚类块内的离散程度作为评价标准,对系统内的工件和机床进行了聚类。

CIMS优化排序的度量空间分析法

本文建立了排序的度量空间,并且在该空间上建立了映射概念.在此基础上,应用采样方法,讨论了采样次数与优化的关系,并提出了均匀采样的启发式方法.

数控自动编程专家系统

本文简要地介绍了数控自动编程专家系统.其中包括:专家系统知识表示的形式;分层次的黑板结构;前向推理求解策略和相应的解释功能;系统针对不同类型的曲线组合,采用不同的独立的知识源(KS)进行处理.由于在知识的处理上采用编码技术,在前向推理求解策略中使用启发信息和“剪技”技术,提高了系统的时空效率.系统中的规划程序能自动规划切削路径.输出供数控车床使用的 NC 代码,并可在显示屏上进行图形显示和切削仿真.目前原型系统已经在 IBM-PC 和 Sun3/60计算机上利用FORTRAN 语言实现.