ISD单片语音录／放器件及电路设计   总被引：1，自引：0，他引：1  

刘连吉 《海洋技术学报》1997,16(3):38-45

ＩＳＤ单片语音器件的独特之处，是有用直接模拟存储技术，语音信号以其原本的模拟形式直接存入模拟量存储器中并长远保存。省去了传统的Ａ／Ｄ和Ｄ／Ａ数模转换机制，能高保真的将语音内容再生。这是一种高新录／放技术。另外，给出的ＩＳＤ基本录／放电路十分简单易用。可方便地为微机系统、测控仪表、电器和广播等设备所采用，使设备具有高效功能。  相似文献   

Classification of radio elements using mutual information: A tool for geological mapping     

P.T. Krishna Kumar  V.V. Phoha  S.S. Iyengar 《International Journal of Applied Earth Observation and Geoinformation》2008

A broad range of current airborne gamma ray spectrometry (AGRS) applications involve environmental mapping and mineral exploration. One common goal for such applications is the development of an algorithm for reliable on line classification of radio elements. In this paper, we propose the concept of maximization of correlated information as the similarity measure for classification. In order to achieve this similarity measure, we have developed an algorithm using the concept of minimization of mutual information, which is computationally faster, and requiring less memory than the hierarchical agglomerative clustering (HAC) method. The minimization of mutual information is achieved by maximizing the correlated information of the correlation matrix. The correlated information is maximized by the determination of its lower bound using the technique of determinant inequalities developed by us. We demonstrate the robustness of our results using mutual information and its superiority over that of Ward's method of minimum variance for the aerial survey carried out in central India.  相似文献   

Cost Optimization of Reinforced Earth Walls   总被引：1，自引：0，他引：1  

P. K. Basudhar  Amol Vashistha  Kousik Deb  Arindam Dey 《Geotechnical and Geological Engineering》2008,26(1):1-12

This paper deals with optimum cost (objective function) design of geosynthetic reinforced earth retaining walls subjected to static and dynamic loading. The design restrictions are imposed as design constraints in the analysis. Choice of the initial designed length and strength of the reinforcement, which are the elements of the design vectors are made in a way that it forms an initial feasible design vector. Thus the problem is one of mathematical programming. The constraints and the objective function being nonlinear in nature, the Sequential Unconstrained Minimization Technique (SUMT) has been used in conjunction with conjugate direction and quadratic fit methods for multidimensional and unidirectional minimization to arrive at the optimal (minimum) cost of the reinforced earth wall. Optimal cost tables are presented for different combinations of the loading and the developed procedure is validated by taking up an example problem. It has been found from the typical example problem that saving of the order of 7–8% can be made over the conventional design of mechanically stabilized earth (MSE) walls with the aid of design charts.  相似文献   

遥感影像解译标志库的建立和应用   总被引：2，自引：0，他引：2  

江涛 《地理空间信息》2010,8(5):31-33

在遥感影像解译标志库中,全面、综合地总结了各种解译要素和常见的各种典型地物及其解译标志。该库具有全面性、综合性、开放性和包容性的特点。同时,结合该遥感影像解译标志库,成功地实现了对研究区的遥感地质解译。根据所建立的解译标志库系统地总结了研究区各种岩性的遥感影像特征;解译结果与1:200000地质资料相对比,共发现18处影像特征与其不一致的地方。经野外验证,根据解译标志库所建立的不同岩性的解译标志及解译结果是准确可靠的。  相似文献   

An experimental investigation of hydrodynamic coefficients for a vertical truncated rectangular cylinder due to regular and random waves     

V. Vengatesan  K. S. Varyani  N. Barltrop   《Ocean Engineering》2000,27(3)

The research into hydrodynamic loading on ocean structures has concentrated mostly on circular cross-section members and relatively limited work has been carried out on wave loading on other cross-sections such as rectangular sections. These find applications in many offshore structures as columns and pontoons in semi-submersibles and tension-leg platforms. The present investigation demonstrates the behaviour of rectangular cylinders subject to wave loading and also supplies the hydrodynamic coefficients for the design of these sections.This paper presents the results of wave forces acting on a surface piercing truncated rectangular cylinder set vertically in a towing tank. The experiments are carried out in a water depth of 2.2 m with regular and random waves for low Keulegan–Carpenter number up to 6. The rectangular cylinder is of 2 m length, 0.2 m breadth and 0.4 m width with a submergence depth of 1.45 m from still water level. Based on Morison equation, the relationship between inertia and drag coefficients are evaluated and are presented as a function of KC number for various values of frequency parameter β, for two aspect ratios of cylinders, equals to 1/2 and 2/1. Drag and inertia coefficients obtained through regular wave tests are used for the random wave analysis to compute the in-line force spectrum.The results of the experiments show the drag and inertia coefficients are strongly affected by the variation in the aspect ratios of the cylinder. The drag coefficients decreases and inertia coefficients increases with increase in Keulegan–Carpenter number up to the range of KC number tested. The random wave results show a good correlation between measured and computed force spectrums. The transverse forces in both regular and random waves are found to be small compared to in-line forces.  相似文献   

遥感技术直接找油理论基础及其实践     

郭德方 《遥感学报》1995,(1)

本文在综合研究近年来国内外遥感技术直接找油这一领域研究成果的基础上，系统归纳出烃类微渗漏理论；给出了遥感技术直接探测油气藏的模型；概述了遥感技术直接找油的现状并对其未来的发展提出了看法。  相似文献   

平衡剖面技术的研究现状及进展   总被引：4，自引：2，他引：2  

张向鹏  杨晓薇 《煤田地质与勘探》2007,35(2):78-80

介绍了平衡剖面技术的发展历史,总结了各发展阶段的主要思想和所取得的成果以及发展状况、研究思路、存在的不足和研究进展等。   相似文献   

岩溶区隧道涌水研究现状及建议   总被引：43，自引：7，他引：36  

蒙彦  雷明堂 《中国岩溶》2003,22(4):287-292

主要从涌水量预测、地质超前预报技术和涌水处理三个方面总结分析了岩溶区隧道涌水的研究现状,并就相关问题进行了探讨,提出了自己的见解。   相似文献   

基于改进多分类孪生支持向量机的测井岩性识别方法研究与应用     

苏赋  马磊  罗仁泽  倪艳 《地球物理学进展》2020,(1):174-180

岩性识别是认识地层及求解储层参数的基础,受地质环境复杂性和非均质性影响,测井曲线间存在着大量的信息冗余,数据集类间分布不平衡,常用的分类算法无法满足实际需求.针对常用分类算法容错性差,识别岩性单一和无法有效解决类间不平衡的问题,本文改进合成少数过采样技术(Synthetic Minority Over Sampling Technique,SMOTE)来处理数据集,可得到类间平衡的新数据集,并提出一种新的模糊隶属度函数改进模糊孪生支持向量机,在北美Hugoton油气田实际测井数据的基础上,用改进多分类孪生支持向量(Improve Multi Class Twin Support Vector Machine,IMCTSVM)综合自然伽马(GR)、电阻率(RL)、光电效应(PE)、中子密度孔隙度差异(DPHI)和平均中子密度孔隙度(PHIND)五种测井参数,以及相对位置(RELPOS)和非海洋/海洋指标(NM_M)两种地质约束变量,识别出9种岩性.将识别结果与传统支持向量机、深度神经网络等方法进行对比与分析,发现IMCTSVM算法优于上述两种分类算法,取得了较好的识别效果.  相似文献   

Search for TeV gamma-rays from Geminga pulsar     

B.B. Singh  V.R. Chitnis  D. Bose  M.A. Rahman  S.S. Upadhya  K.S. Gothe  B.K. Nagesh  P.N. Purohit  Shobha K. Rao  Kamesh K. Rao  S.K. Sharma  P.V. Sudersan  B.L. Venkateshmurthy  P.R. Vishwanath  B.S. Acharya 《Astroparticle Physics》2009,32(2):120-128

We present the results of observation of the Geminga pulsar carried out in the TeV energy band during the 6 year period spanning 2000–2006 using the Pachmarhi Array of Cherenkov Telescopes (PACT). A long stretch of data, new computer codes and the “Tempo” package have been used in the present analysis. We have searched for evidence of pulsed emission of γ-rays from the Geminga pulsar using the post-glitch pulsar elements obtained by Jackson and Halpern from X-ray/γ-ray satellite data. We do not see any significant evidence for pulsed emission from the Geminga pulsar at a threshold energy of 825 GeV. In this paper we present our results on the light curve in the TeV energy band, set an upper limit on the time averaged flux of γ-rays, and compare our results with other ground based observations.  相似文献