http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Ramakar Jha (검색결과 5 건)
- 무료
- 기관 내 무료
- 유료
-
Ramakar Jha,K.D. Sharma,V.P. Singh 대한토목학회 2008 KSCE JOURNAL OF CIVIL ENGINEERING Vol.12 No.3
In recent years, many hydrology-based approaches have been used to assess the environmental flows in various riversystems over the globe. However, their application has been very limited in India. Brahmani and Baitarani River basins inIndia are two important water surplus basins, in which several water resources projects are coming up shortly. There is anurgent need for the water planners and stakeholders to assess best management practices of available water resources. The present paper (i) critically evaluates the applicability of existingapproaches, (ii) provides values of environmental design flows at different locations of Brahmani and Baitarani River systems,and (iii)suggest a suitable scientific approach for the assessment of environmental flows.
-
Evaluation of Riverwater Quality by Entropy
Ramakar Jha,Vijay P. Singh 대한토목학회 2008 KSCE JOURNAL OF CIVIL ENGINEERING Vol.12 No.1
As a measure of uncertainty of a system, entropy is employed as an indicator of the influx of pollutants from point as well as non-point sources of pollution to river systems in India. Most of the Indian rivers receive pollutants from municipal and industrial wastes,which are disposed without proper treatment. In addition, non-point source pollution also enters the receiving surface water diffuselyat intermittent intervals. In this study, entropy is used to evaluate the water quality at different locations of six river systems in India:Baitarani, Brahmani, Malprabha, Pachin, Gomti and Yamuna. Two water quality variables, viz., dissolved oxygen (DO) andbiochemical oxygen demand (BOD) are considered and their entropy values are determined at different locations for all the six riversystems. However, due to the non-availability of data for Malprabha and Pachin river systems, entropy for electrical conductivity(Ec) and hardness (as CaCO3) is determined only for Baitarani, Brahmani, Gomti and Yamuna river systems. The results indicatesevere water quality conditions in River Yamuna and River Gomti (in the Ganga plains), moderate water quality condition in RiverBairatani (eastern river), and marginal water quality conditions in River Brahmani (eastern river), River Malprabha (southern river)different time scales (during 1990-91 and 1995-96) for River Yamunaand Gomti indicates a gradual increasing trend of pollution.
-
Analysis of Urban Development of Haridwar, India, Using Entropy Approach
Ramakar Jha,Vijay P. Singh,V. Vasta 대한토목학회 2008 KSCE JOURNAL OF CIVIL ENGINEERING Vol.12 No.4
Urban development is a complex process, which should be observed at various levels and in many aspects for full understanding.The pervasive problems generated by urban development have prompted, in the present work, to study the spatial extent ofurbanization in Haridwar, India, and patterns of periodic changes in urban development (systematic/random) in order to developfuture plans for (i) urbanization promotion areas, and (ii) urbani sing(IRS) satellite data, was used to map the spatial extent of urbanization for the 1989, 1998, 2000 and 2002 years. GeographicalInformation System (GIS) and Entropy approach, which makes use of mathematical notions related to thermodynamics and is thedisorder of organization or randomness of organization of a system, were used to study the pattern of urban development (systematicor random) in Haridwar, India during 1989-2002. The distributed entropy and relative mean entropy values were evaluatedconsidering two location factors: (i) urban development at peripheries of 1000 m each from the centre of the city (Har Ki Pauri), (ii)urban development at peripheries of 1000 m each from the highway along the upper Ganga canal. The results obtained indicate1989-2002, specificaly after the 1998 year. However, urbandevelopments were found to be random in nature, as the distributed relative entropy values formed a zig-zag pattern for the locationfactor from the centre of the town. The application of entropy is found to be a better alternative to conventional technique.
-
Ramakar Jha,Vijay P. Singh 대한토목학회 2008 KSCE Journal of Civil Engineering Vol.12 No.2
Biochemical Oxygen Demand (BOD) modeling in a river involves derivation and solution of the governing partial differentialequation, which describes concentration change with time and space due to convection, dispersion, decay and the loading function. Inthis study, an analytical model is developed for BOD simulation for the boundary condition when the waste discharge concentrationcan be described a sinusoidal variation. The analytical model is obtained by solving the governing partial diferential equationthrough any cross-section so that a one dimensional model isapplicable and (ii) for specific initial and boundary conditions. The results of the model for BOD simulation validated for (i) waterquality data from River Gomti in India, which is an important tributary of Ganga River with significant influx of pollutants, and (ii)the data sets used for validation of commonly used analytical models and are available in the published literature. The proposedmodel is found to represent the physical processes occurring in River Gomti with high correlation between observed and simulatedBOD values. Moreover, the results obtained from other data sets published in the literature demonstrate the applicability of developedanalytical model for BOD simulation.
-
Application of Support Vector Regression for Modeling Low Flow Time Series
Bibhuti Bhusan Sahoo,Ramakar Jha,Anshuman Singh,Deepak Kumar 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.2
Hydrologic time series modeling using historical records plays a crucial role in forecasting different hydrological processes. The objective of this study is to analyze the suitability of Support Vector Regression (SVR) for modeling monthly low flows time series for three stations in Mahanadi river basin, India. The ‘low flow’ threshold was taken as the Q75 discharge, i.e., the flow is equal to or surpassed for the duration of 75% of the observation period which was obtained from the daily discharge data. The potential applicability of SVR model is assessed with two different framework models (ANN-ELM, GPR) based on various statistical measures (r2, RMSE, MAE, Nash-Sutcliffe coefficient, objective function (OBJ), Scatter Index (SI) and BIAS). The model selection was based on lowest OBJ value for each station amongst three models (SVR, ANN-ELM, GPR). The SVR model was trained using the Radial Basis Function (RBF). Using the same inputs, the other two models (ANN-ELM and GPR) was also tested. From results, among all the stations, the SVR outperformed GPR and ANN-ELM with lowest OBJ value for the three stations a (1.378, 1.202, 1.570). In addition, the accuracy of the three models were checked using mean forecasting error which were (0.474, 0.421, 0.509) for SVR, (0.507, 0.489 0.500) for GPR and (0.564, 0.603, 0.772) ANN-ELM for the three stations. The results confirm that SVR can be used satisfactorily for modeling monthly low flows in the Mahanadi river basin, India. Hence, the SVR model could be employed as a new reliable and accurate data intelligent approach for predicting the ‘low flow’ (Q75 discharge) based on precedent data in water resources and its allied field.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
