Fluviomorphological investigations in the flood plain area of river satluj in the North East of Ludhiana (Punjab State) using photo-interpretation techniques     

B. D. Singh  A. K. Goel 《Journal of the Indian Society of Remote Sensing》1984,12(2):47-52

Various geomorph.ological features associated with fluvial processes of the river Satluj are mapped using photo-interpretation techniques with a view to assess the environmental status of the area in the north-east of Ludhiana (Punjab State). Features mapped include braided river channels, oxbow lakes and meander scrolls. The younger alluvium supports good vegetation and cultivation because of -shallow depth of water level; though prone to annual floods in the lower levels and major floods in the higher levels. It is saved from these hazards by providing bunding on both sides of river isolated sand deposit patches have been demarcated in the older alluvium. Shifting of the main river channel towards north is noticed as it has gradually shifted from its earlier course which lies towards south.  相似文献   

Seismic behaviour of asymmetric buildings with supplemental damping     

Rakesh K. Goel 《地震工程与结构动力学》2000,29(4):461-480

This paper investigates the response of asymmetric‐plan buildings with supplemental viscous damping to harmonic ground motion using modal analysis techniques. It is shown that most modal parameters, except dynamic amplification factors (DAFs), are affected very little by the plan‐wise distribution of supplemental damping in the practical range of system parameters. Plan‐wise distribution of supplemental damping significantly influences the DAFs, which, in turn, influence the modal deformations. These trends are directly related to the apparent modal damping ratios; the first modal damping ratio increases while the second decreases as CSD moves from right to left of the system plan, and their values increase with larger plan‐wise spread of the supplemental damping. The largest reduction in the flexible edge deformation occurs when damping in the first mode is maximized by distributing the supplemental damping such that the damping eccentricity takes on the largest value with algebraic sign opposite to the structural eccentricity. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

Seismic code analysis of multi-storey asymmetric buildings     

Anthony P. Harasimowicz  Rakesh K. Goel 《地震工程与结构动力学》1998,27(2):173-185

Static torsional provisions in most seismic codes require that the lateral force at each floor level be applied at some distance from the reference centre at that floor. However, codes do not specify how to determine the locations of these centres. As a result, several different definitions of the reference centres are being used to implement the code analysis. This investigation examined how the results using various reference centres differ and which of these centres would lead to results that are in agreement with those of dynamic analysis. For this purpose three different buildings ranging form torsionally stiff to torsionally flexible were analysed. It was shown that for the class of buildings studied in this investigation that although the locations of the reference centres were quite different, the results were very similar and nearly independent of the reference centre. Comparison of results calculated from static code equivalent lateral force procedures and results from dynamic response spectrum analyses showed that the static code procedures led to design forces very close (flexible wall) or slightly conservative (stiff wall) when compared to the dynamic analysis for the torsionally stiff building. However, the static code procedures significantly underestimated the design forces of the stiff walls and significantly overestimated the design forces of the flexible walls for the torsionally flexible buildings. © 1998 John Wiley & Sons, Ltd.  相似文献   

Comparative study of neural network,fuzzy logic and linear transfer function techniques in daily rainfall‐runoff modelling under different input domains     

Anil Kumar Lohani  N. K. Goel  K. K. S. Bhatia 《水文研究》2011,25(2):175-193

This paper compares artificial neural network (ANN), fuzzy logic (FL) and linear transfer function (LTF)‐based approaches for daily rainfall‐runoff modelling. This study also investigates the potential of Takagi‐Sugeno (TS) fuzzy model and the impact of antecedent soil moisture conditions in the performance of the daily rainfall‐runoff models. Eleven different input vectors under four classes, i.e. (i) rainfall, (ii) rainfall and antecedent moisture content, (iii) rainfall and runoff and (iv) rainfall, runoff and antecedent moisture content are considered for examining the effects of input data vector on rainfall‐runoff modelling. Using the rainfall‐runoff data of the upper Narmada basin, Central India, a suitable modelling technique with appropriate model input structure is suggested on the basis of various model performance indices. The results show that the fuzzy modelling approach is uniformly outperforming the LTF and also always superior to the ANN‐based models. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Automated Detection, Characterization, and Tracking of Sunspots from SoHO/MDI Continuum Images     

Suruchi Goel  Shibu K. Mathew 《Solar physics》2014,289(4):1413-1431

We describe a procedure for automated detection of sunspots from SoHO/MDI full-disk continuum images. The MDI Level-1.8 continuum images were first corrected for the limb darkening and stray light, and then were flat-fielded. Sunspots were extracted using a newly developed automated sunspot detection procedure, which is based on the level set, namely the selective binary and Gaussian function regularized level set (SBGFRLS) method (Zhang et al., Image Vis. Comput. 28, 668, 2010). In this method we initialize a two-dimensional level-set function and evolve it using a signed pressure force (SPF) function. For sunspot detection, the level-set function was defined twice, first for umbra and then for penumbra extraction. Using this procedure, along with the characterization of detected sunspots we have also generated tracking reports of all sunspots in a fully unsupervised manner.  相似文献   

LITHIUM IN STONE METEORITES AND STONY IRONS     

S.V.S. Murty  P.N. Shukla  P.S. Goel 《Meteoritics & planetary science》1983,18(2):123-136

Lithium contents have been determined by neutron activation analysis in 54 meteorites distributed as: C (9), H (13), L (10), LL (3), E (2), achondrites (11), and stony irons (6). Among the undifferentiated meteorites Li contents range from 1 to 3 ppm. Li contents are higher in Ca-rich achondrites and mesosiderites than in Ca-poor achondrites and pallasites respectively. Among achondrites, Li correlates positively with Ca and Al and inversely with Mg. A minor Li-rich phase might be associated with the plagioclase component of achondrites. In several meteorites Li concentration is determined in magnetic and nonmagnetic fractions, chondrules, and light and dark components (for the gas-rich meteorites).  相似文献   

Development of unbiased plotting position formula for General Extreme Value distributions     

N. K. Goel  M. De 《Stochastic Hydrology and Hydraulics》1993,7(1):1-13

Expressions for the expected values of GEV order statistics have been derived in simple summation form and in terms of probability weighted moments. Using exact plotting positions from GEV order statistics a new unbiased plotting position formula has been developed for the General Extreme Value distribution. The formula can, explicitly, take into account the coefficient of skewness, (or the shape parameter, k), of the underlying distribution.The developed formula better approximates the exact plotting positions as compared to other existing formulae and is quite easy to use.  相似文献   

Modeling river discharge time series using support vector machine and artificial neural networks     

Mohammad Ali Ghorbani  Rahman Khatibi  Arun Goel  Mohammad Hasan FazeliFard  Atefeh Azani 《Environmental Earth Sciences》2016,75(8):685

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Zircon U‐Pb/Lu‐Hf and monazite chemical dating of the Tirodi biotite gneiss: implication for latest Palaeoproterozoic to Early Mesoproterozoic orogenesis in the Central Indian Tectonic Zone     

Santanu Kumar Bhowmik  Simon A. Wilde  Anubha Bhandari 《Geological Journal》2011,46(6):574-596

In this investigation, we reconstruct the latest Palaeoproterozoic to Early Mesoproterozoic orogenic events along the southern margin of the Central Indian Tectonic Zone (CITZ), using sensitive high resolution ion microprobe (SHRIMP) U‐Pb zircon dating and Lu‐Hf isotope analyses of zircon and Th‐U‐Pb chemical dating of monazite from samples of the Tirodi biotite gneiss (TBG) unit in the Sausar Mobile Belt (SMB), the latter constituting the southernmost litho‐tectonic component of the CITZ. U‐Pb zircon dating of one migmatitic gneiss sample from the type locality of the Tirodi biotite gneiss in the northern domain of the SMB has yielded an age of 1618 ± 8 Ma, which is considered to be the time of magmatic crystallization of its protolith. Combined U‐Pb zircon and monazite chemical dating of two granite gneiss samples from the southern domain of the SMB broadly constrain magmatic crystallization between 1603 ± 23 Ma and 1584 ± 17 Ma and an overprinting metamorphic recrystallization event at 1572 ± 7 Ma. Monazites from the granite gneiss samples also record a terminal metamorphic event at 1415 ± 23 Ma. Lu‐Hf isotopic analyses of zircons reveal fundamentally different source rock reservoirs for the protoliths of these magmatic rocks across the SMB. While the type TBG from the northern domain was derived from an Early Palaeoproterozoic source T(Hf) from 2093 to 2523 Ma, with a mean value at 2379 Ma) of essentially juvenile material with minor crustal components (εHf(t) from −3.3 to + 3.7), the granite from the southern domain had a mature crustal source (εHf(t) from −12.5 to −21.9) of Palaeoarchaean age T(Hf) from 3051 to 3630 Ma, with a mean value at 3218 Ma). When integrated with metamorphic information previously obtained from the 1.6 Ga ultra‐high temperature granulite facies metamorphic event in the SMB, the discrete magmatic and metamorphic events between 1.62/1.60 Ga and 1.42 Ga can be correlated with the formation of an Early Mesoproterozoic accretionary orogen in the CITZ. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Developing Basic Design and Mathematical Framework for a Mobile Mapping System—a Case Study Using Available Sensors     

Manohar Yadav  Salil Goel  A. K. Singh  Bharat Lohani 《Journal of the Indian Society of Remote Sensing》2014,42(2):301-310

There is a growing demand for technologies that support capturing of comprehensive and good quality 3D spatial data at a faster rate with low investment and minimal effort, while also causing least disturbance to other activities in the area. Mobile mapping systems (MMS), which are being developed in a few western countries, solve this problem but their import is highly expensive. While the components of a MMS are easily available off-the-shelf at lower cost, the main reason for their high cost is the intellectual property involved in the sensor design, integration, calibration, and the related software. Developing the intellectual property locally can bring down the cost of MMS to a large extent. Keeping this in mind, a MMS has been developed in this research using the locally available sensors. This paper describes the methodology to integrate navigation and mapping sensors including the developed calibration procedures. It further describes the time synchronization technique developed for multi-sensor data fusion and algorithms implemented by software package for data processing. The sensors integrated in the MMS include a standard GPS, IMU and a standard laser scanner. A Kalman filter is implemented to integrate the GPS and IMU data, which provides position and orientation information for the sensors. A simulation software package is also developed to verify, understand and develop the equations used in MMS. Field tests have been performed using the developed MMS and the results are shown for a few cases. Results validate the designed algorithms and indicate the successful development of the MMS, which has potential to be further developed and used in field. Though a number of papers are available on MMS, the thrust of this paper is to present a complete methodology for developing a MMS using locally available sensors. Unlike available papers, this paper outlines all aspects of design, calibration and operation, where each of these aspects is handled in a novel way as demanded by the available sensors. This is particularly useful for individuals or organizations interested in procuring sensor components off-the-shelf and develop their own (low cost) Mobile Mapping system.  相似文献