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61.
S.N. Londhe   《Ocean Engineering》2008,35(11-12):1080-1089
This paper presents soft computing approach for estimation of missing wave heights at a particular location on a real-time basis using wave heights at other locations. Six such buoy networks are developed in Eastern Gulf of Mexico using soft computing techniques of Artificial Neural Networks (ANN) and Genetic Programming (GP). Wave heights at five stations are used to estimate wave height at the sixth station. Though ANN is now an established tool in time series analysis, use of GP in the field of time series forecasting/analysis particularly in the area of Ocean Engineering is relatively new and needs to be explored further. Both ANN and GP approach perform well in terms of accuracy of estimation as evident from values of various statistical parameters employed. The GP models work better in case of extreme events. Results of both approaches are also compared with the performance of large-scale continuous wave modeling/forecasting system WAVEWATCH III. The models are also applied on real time basis for 3 months in the year 2007. A software is developed using evolved GP codes (C++) as back end with Visual Basic as the Front End tool for real-time application of wave estimation model.  相似文献   
62.
The correlation of geological records is commonly based on subjective and arbitrary interpretation by a researcher. Geological data are usually collected as a series on a depth scale, and then chronologies of the profiles are constructed. The correlation of geological records based on matching quality indicators requires an efficient method of searching for the best position. GenCorr is a software based on a genetic algorithm, for correlation of records with or without accompanying chronological control. Where their age information is available, points on both records may be moved in the range limited by the age uncertainties. GenCorr has been developed by the authors in Borland RAD Studio 2007 environment. The authors tested the impact of matched record length, noise level, sampling resolution, or additional linear components and hiatuses on the correlation results using artificial test data. Finally, the genetic algorithm was applied to stable isotope records obtained from two stalagmites collected from the Demianova Cave System (Low Tatras, Slovakia). The results show that the genetic algorithm correlation method is similar to that used in pattern recognition by the human eye without prior knowledge of the ages. The genetic algorithm is able to correlate in multidimensional space and is free from human biases, but we accept that there are also occasions where additional expert opinion may be also important. GenCorr can be run on every PC with MS Windows operating system, the package was not tested in Mac environment. GenCorr is available as a freeware from the authors. For downloading, please contact: dzeq@twarda.pan.pl.  相似文献   
63.
根据天水地震台SK地震仪近年来记录的338个震例的资料,用最小二乘法求出最大振幅面波与初至波至时差同震中距的关系式,并与J-B表进行了对比,结果表明,用J-B表计算出的震中距与实际震中距的偏差较大,用本给出的关系式和走时表估算震中距可以缩小误差,提高定位精度。  相似文献   
64.
地下管网是城市正常运转的基础设施,承载着城市各种物质流、能源流和信息流,保证了城市的有序运转和居民的正常生活。探测地下管线的主要设备是英国雷迪RD8000,但这种设备恰巧是测绘仪器检定的盲区。为保证探测精度,需对物探方法进行分析,对设备进行校验,对不同埋深、不同地电条件下金属管线探测的工作参数进行试验,对探测仪性能、方法、最佳收发距离进行综合评定,旨在最大限度地发挥探测仪的潜能,从而保证地下管网的探测精度。  相似文献   
65.
斑岩铜矿是指与具斑状结构的中酸性侵入岩伴生,蚀变与矿化受流体、构造控制且分带明显,矿石以细脉浸染状为主,低品位、大储量的铜矿床,是最重要的铜矿床类型。大地构造背景对斑岩铜矿的形成具有重要意义,经典的斑岩铜矿主要产于岛弧、陆缘弧环境。然而,近年来国内矿床学家发现,国内形成于大陆环境的斑岩铜矿与大洋板块俯冲、板块消减作用无关,斑岩铜矿还可产于碰撞造山带,甚至是在陆内环境。相比之下,不同构造背景下形成的斑岩铜矿床含矿岩浆、成矿物质来源、矿床成因等方面存在一定差异与共性。综述了目前斑岩铜矿研究内容中的关于构造背景的一些重要观点和几个重要进展,对比了不同构造背景下形成的斑岩铜矿床的含矿岩浆、蚀变矿化、成矿流体等方面的共性与差异,以期对斑岩型矿床的成因与找矿提供一定的线索。  相似文献   
66.
采用数字化台网P波波形资料及台湾台网P波初动方向资料,研究了1994年9月16日台湾海峡73级地震及邻近地区(北纬21~26°,东经115~120°)ML≥58级共5次地震的矩张量解及震源参数。结果表明,这次73级地震的矩张量解以双力偶成分为主,是断层面接近NW走向的正断层。断层面的走向与大震前地震的条带分布走向及余震分布显示的破裂图象较相象,震源机制的张应力轴接近水平,近NE走向;压应力轴几乎垂直,近NWW走向,似乎表明这次地震是受菲律海板块向欧亚板块北西向挤压的力源控制。从P轴接近竖直而T轴接近水平来看,发震断层为强烈拉张性正断层,可能还同时存在垂直向上的应力作用。其它4个强震的震源机制解与73级大震的差别较大。这些地震震源机制解的复杂性,表明台湾海峡地震序列的发展过程比较复杂。  相似文献   
67.
Cepheid parallaxes and the Hubble constant   总被引:1,自引:0,他引:1  
Revised Hipparcos parallaxes for classical Cepheids are analysed together with 10 Hubble Space Telescope ( HST )-based parallaxes. In a reddening-free V , I relation we find that the coefficient of log  P is the same within the uncertainties in our Galaxy as in the Large Magellanic Cloud (LMC), contrary to some previous suggestions. Cepheids in the inner region of NGC 4258 with near solar metallicities confirm this result. We obtain a zero-point for the reddening-free relation and apply it to the Cepheids in galaxies used by Sandage et al. to calibrate the absolute magnitudes of Type Ia supernova (SNIa) and to derive the Hubble constant. We revise their result for H 0 from 62 to 70 ± 5 km s−1 Mpc−1. The Freedman et al. value is revised from 72 to 76 ± 8 km s−1 Mpc−1. These results are insensitive to Cepheid metallicity corrections. The Cepheids in the inner region of NGC 4258 yield a modulus of 29.22 ± 0.03 (int.) compared with a maser-based modulus of 29.29 ± 0.15. Distance moduli for the LMC, uncorrected for any metallicity effects, are 18.52 ± 0.03 from a reddening-free relation in V , I ; 18.47 ± 0.03 from a period–luminosity relation at K ; 18.45 ± 0.04 from a period–luminosity–colour relation in J , K . Adopting a metallicity correction in V , I from Macri et al. leads to a true LMC modulus of 18.39 ± 0.05.  相似文献   
68.
A value for the zero-point (ρ) of the Cepheid period–luminosity relation, <  M V  >= 2.81 log P  + ρ, is deduced by comparing the value of the Oort constant, A , derived from radial velocities with that derived from Hipparcos proper motions. We find in this way that ρ =−1.47 ± 0.13, in excellent agreement with the value derived from Hipparcos trigonometrical parallaxes, ρ = −1.43 ± 0.10, by Feast &38; Catchpole in a recent paper.  相似文献   
69.
We discuss how the redshift (Mattig) method in the Friedmann cosmology relates to dynamical distance indicators based on Newton's gravity (Teerikorpi 2011). It belongs to the class of indicators where the relevant length inside the system is the distance itself (in this case the proper metric distance). As the Friedmann model has a Newtonian analogy, its use to infer distances has instructive similarities to classical dynamical distance indicators. In view of the theoretical exact linear distance‐velocity law, we emphasize that it is conceptually correct to derive the cosmological distance via the route: redshift (primarily observed) → space expansion velocity (not directly observed) → metric distance (physical length in “cm”). Important properties of the proper metric distance are summarized. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   
70.
吉林省浑江市荒沟山区花岗岩成因类型探讨   总被引:4,自引:0,他引:4  
王速  邢树文 《吉林地质》1994,13(2):36-41
本文根据吉林省浑江市荒沟山区中生代花岗岩的岩石学、地球化学及同位素地质学研究,论述了该区花岗岩的成因类型,即老秃顶子岩体、梨树沟岩体、草山岩体均为同熔型。  相似文献   
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