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关键词： .Multivariate   Schemes   quantification   discriminant   Department of Forest   Using GIS   stratified random   hazard maps   landslide hazard assessment   factors and classes   non-landslide group  

摘要： An application of Gls for landslide hazard assessment using multivariate statistical analysis, mapping, and the evaluation of the hazard maps is presented. The study area is the Kulekhani watershed (124 km(2)) located in the central region of Nepal. A distribution map of landslides was produced from aerial photo interpretation and field checking. To determine the factors and classes influencing landsliding, layers of topographic factors derived from a digital elevation model, geology, and land use/land cover were analyzed by quantification scaling type ii (discriminant) analysis, and the results were used for hazard mapping. The effects of different samples of landslide and non-landslide groups on the critical factors and classes and subsequently on hazard maps were evaluated. Simple random sampling was used to obtain samples of the landslide group, and either an unaligned stratified random sampling or an aligned systematic sampling method generated the non-landslide group. For the analysis, one set of the landslide group was combined with each of five different sets of the non-landslide groups. Combinations of different samples yielded some minor differences in the critical factors and classes. The geology was found to be the most important factor for landslide hazard. The scores of the classes of the factors quantified by the five analyses were used for the hazard mapping in the Gls, with four levels of relative hazard classes: high, moderate, less, and least. The evaluation of five hazard maps indicated higher accuracy for the combinations in which the non-landslide group was generated by the unaligned stratified random sampling method. The agreements in the hazard maps, produced from different sample combinations using unaligned stratified random sampling for selecting non landslide group, were within the acceptable range for the practical use of a hazard map.

关键词： 神经网络   图像分割   脉冲耦合   可编程逻辑器件  

摘要： 该文深入研究了一种基于生物视觉模型的神经网络-脉冲耦合神经网络,并将其应用于图像分割和去噪之中.首先,该文通过对脉冲耦合神经网络时间序列的分析,得到将脉冲耦合神经网络用于图像分割的有效途径.然后了脉冲耦合神经网络用于图像处理时的优良必,包括对于输入图像平移及旋转的不变性,又具体分析了脉冲耦合神经网络对于输入图像的尺度变化的不变性的条件.在用脉冲耦合神经网络对标准图像及其旋转和尺度变化图像进行分割的实验中,很好的验证了这些优点.此外,还根据脉冲耦合神经网络对于非相似性输入的异步输出,将其用于图像去噪,由实验可知,用PCNN进行图像去噪不仅能够有效的去除噪声,而且能够很好的保持图像的边缘.

关键词： Eucalyptus camaldulensis   myrtaceae   essential oil composition   p-cymene   cryptone  

摘要： The freshly distilled essential oil from the leaves of Eucalyptus camaldulensis collected in Tampa, FL, were analyzed by GC/MS. The major constituents identified in the oil included p-cymene (35.0%), cryptone (13.7%), terpinen-4-ol (5.7%), spathulenol (4.3%), and cuminaldehyde (3.7%). Relatively a very low amount of 1,8-cineole (2.7%) was found. The oil was not typical in chemical composition of the high cineole types of this species most often referenced in the literature and was found to be one of the highest cryptone containing essential oils yet reported.

摘要： Samples of [4-H-2(1)]-1-deoxyxylulose (17a) and [2-C-13, 4-H-2(1)]-1-deoxyxlulose (17b), have been prepared by modification of known procedures and fed in aqueous solution to twiglets of Eucalyptus globulus. The probes of cineol (6) isolated from these experiments were analyzed by GC/MS, H-2- and C-13-NMR techniques. In the experiments with lm, the formation of five isotopomers of 6 could be detected. Their structure and relative abundance demonstrate that the C-13-label is incorporated to the same extent into the two C-5-units of 6, and that the H-2 label is retained to an extent of 57% in the starter dimethylallyl-diphosphate unit (DMAPP;12), but completely or almost completely lost in the unit derived from isopentenyl diphosphate (IPP;11), in the elongation step which leads to geranyl diphosphate (GPP;1). These results confirm that the recently discovered mevalonate-independent pathway to IPP and DMAPP is operative in the biosynthesis of cineol, and indicate, together with previous finding, that, within this pathway, formation of IPP and DMAPP occurs in independent rather than in sequential steps. In addition, the demonstration of different metabolic origins for the olefinic H-atoms of GPP (1), the aliphatic C-10-precursor of 6, paves the way for a realistic interpretation of the strikingly consistent but hitherto unexplained anomalies detected in the natural-abundance H-2-NMR spectra of (+)- and (-)-alpha-pinene and of (+)-limonene.

关键词： Neural networks (Computer science)   Multichip modules (Microelectronics)  

摘要： The constraints imposed by the present technology limit the maximum number of neural components that can be defined on a single chip and the number of wires for interconnections. In order to implement larger perceptive systems with more complex functionality, multi-chip architectures with efficient communication scheme are desirable. The address-event representation (AER) encodes analog signals using asynchronously produced fixed-height, fixed-width pulses, by temporal multiplexing the addresses of the firing neurons onto a single digital bus. This reduces drastically the number of physical interconnections required. Up to the present, most applications of the AER have been in feed-forward neural networks；This thesis investigates the stability and functionality of a class of recurrent neural networks, where feedback interconnections are governed by the AER. In particular, we focus on a type of winner-take-all (WTA) network. WTA networks have been playing a very important role in the design of unsupervised learning neural networks, and various implementations have been proposed recently since the first hardware model by Lazzaro and his colleagues. Also, the WTA networks have close relationship with most of the recurrent cortical models in the primary visual cortex (Vl), from simple orientation-selectivity [4] to contour integration [5]；Based upon both theoretical analysis and intensive simulation results, we find that it is feasible to implement WTA networks in a pulse coupled manner. Criteria for selecting design parameters have been developed. We also compare the performances of different asynchronous pulse based communication schemes using the AER on the system level. Our results show that arbitration is the best choice for neuromorphic systems whose activity is sparse in space and in time. These results should be applicable to the implementation of the recurrent cortical competition and other complex networks with pulse coupled techniques. Pulse coupled neural ne

关键词： hypothalamus   inferior lobe   fiber connection   tracer study   fish   percomorph teleost   cytoarchitecture   subdivisions   cell morphology   topography  

摘要： Afferent and efferent fiber connections of the lobus inferior (LI) were studied in a percomorph teleost, Thamnaconus (Navodon) modestus. The LI of Thamnaconus is composed of the nucleus diffusus lobi inferioris (NDLI), the nucleus recessus lateralis pars lateralis et medialis (NRLI and NRLm), and the nucleus centralis lobi inferioris pars anterior et posterior (NCa and NCp). The NDLI receives projections from the secondary gustatory nucleus, preglomerular tertiary gustatory nucleus, corpus glomerulosum, dorsal region of the area dorsalis telencephali pars medialis (dDm), and area dorsalis telencephali pars lateralis. Different subdivisions of the dorsal telencephalon project to discrete regions of the NDLI. The NDLI projects to the corpus mamillare, NRLI, NCa, and NCp. Thus the NDLI could be regarded as an intrahypothalamic relay nucleus. The NCa receives projections from the NDLI and projects to the preglomerular tertiary gustatory nucleus, secondary gustatory nucleus, nucleus lateralis valvulae, and NRLI. The NCa appears to be primarily an extrahypothalamic projection nucleus. The NCp receives projections from the NDLI. Efferent connections of the NCp remain to be studied. The NRLI receives projections from the NDLI, and projects to the nucleus ruber (NR) of Goldstein [1905] and the preglomerular tertiary gustatory nucleus. Dense projections of the NR to the stratum opticum and stratum fibrosum et griseum superficiale of the optic tectum are demonstrated. The NRLm receives projections from the medial part of the dDm. Efferent connections of the NRLm remain unclear. The LI as a whole receives projections from the locus coeruleus and nucleus raphe superior. These results suggest that the LI receives gustatory and/or general visceral information from the secondary and tertiary gustatory nuclei, visual and somatosensory inputs from the corpus glomerulosum. Inputs from the dorsal telencephalic subdivisions could be of various modalities (e.g. visual, acousticolateral,

关键词： 神经网络   信息处理   计算神经科学   脑科学   计算机   工作进展   日本学者   神经系统   发表论文   智能系统  

摘要： 由亚太神经网络联合会(Asia Pacific Neural Networks Assembly APNNA)主办的第6届国际神经信息处理学术大会(ICONIP’98)于10月21～23日在日本北九州召开。在80年代末至90年代初,大型国际神经网络会议每年举办两次,一次在美国国内,一次在美国国外,全盛时每次达1000～2000人与会。近几年来,有关研究工作进展不大。

关键词： brain evolution   phylogeny   bat monophyly   megabats   microbats   primates  

摘要： As part of a large-scale study on brain morphometrics and adaptations in mammals, we addressed the problem of chiropteran evolution. A specific statistical framework was designed to test which of two competing hypotheses (bat monophyly vs, diphyly) is more strongly supported by quantitative brain data. Our analyses, based on 120 species, revealed that megabats and microbats were more closely related to each other than to primates, and illustrated the convergent adaptations of the brain of bats to similar trophic (i.e, feeding related) niches. Ecologically-corrected characters were then used to derive a new phylogeny which also supports the chiropteran clade. The monophyletic origin of bats is the preferred hypothesis to explain brain quantitative evolution in chiropterans and primates.

关键词： 混沌   脑电活动   CNNS   生物医学   脉冲控制法  

摘要： 利用脉冲控制法对含两个神经元的非自治细胞神经网络（ Ｃ Ｎ Ｎ′ｓ）出现的混沌现象进行控制，给出了保证脉冲控制的系统存在周期解的条件，并通过数值仿真实验证实了用很小的外部激励就能控制住混沌。通过观察受控轨道的时间波形，发现利用受控非自治 Ｃ Ｎ Ｎ′ｓ 模型可成功地对生理学中电响应活动信号建模，这一发现为研究人脑或动物大脑中混沌的功能作用提供了非常有用的工具。

关键词： annihilation   CMOS   image processing   neuromorphic pulse delay lines   neuron coupling strength   refractory period   threshold point   VLSI  

摘要： This paper presents a compact architecture for analog CMOS hardware implementation of voltage-mode pulse-coupled neural networks (PCNN's), The hardware implementation methods shows inherent fault tolerance specialties and high speed, which is usually more than an order of magnitude over the software counterpart. A computational style described in this article mimics a biological neural network using pulse-stream signaling and analog summation and multiplication. Pulse-stream encoding technique uses pulse streams to carry information and control analog circuitry, while storing further analog information on the time axis, The main feature of the proposed neuron circuit is that the structure is compact, yet exhibiting all the basic properties of natural biological neurons. Functional and structural forms of neural and synaptic functions are presented along with simulation results. Finally, the proposed design is applied to image processing to demonstrate successful restoration of images and their features.