ASHISH SHUKLA | University of Delhi (original) (raw)

Papers by ASHISH SHUKLA

In the present article, motivated by Jeelani et al. (2013), we have made an attempt to develop an... more In the present article, motivated by Jeelani et al. (2013), we have made an attempt to develop an improved ratio type estimator of population mean using predictive method of estimation by using linear combination of coefficient of skewness and the quartile deviation of auxiliary variable. The mathematical expressions for the bias and mean squared error (MSE) of the proposed estimator up to the first order approximation have been derived. Theoretical efficiency comparison of proposed estimator with the usual ratio estimator, usual product estimator, and Singh et al. (2014) estimators is also made. To amply corroborate the theoretical findings, an empirical study has also been carried out. The suitability of the proposed estimator can be established and appreciated as it has lesser mean squared error, when compared to other widely used estimators.

The present article deals with the predictive estimation of finite population mean using coeffici... more The present article deals with the predictive estimation of finite population mean using coefficient of kurtosis and median of the auxiliary variable under simple random sampling scheme. Motivated by Milton et al. [2017], we have proposed an improved ratio type predictive estimator of finite population mean. Bias and mean squared error (MSE) of the proposed estimator are also obtained up to first order of approximation. Theoretical efficiency comparison of proposed estimator with Bahl and Tuteja [1991] estimator and Singh et al. estimator [2014] has also been carried out. Optimum conditions, under which the proposed estimator performs better than the competing estimators are also derived. To amply corroborate the theoretical findings, an empirical study has also been carried out. The percent relative efficiencies of the proposed estimator over existing estimators have also been obtained. The suitability of the proposed estimator can be established and appreciated as it has lesser mean squared error, when compared to other widely used estimators.

Solar Energy, 2008

In this paper experimental study has been carried out in a cascade greenhouse with inner thermal ... more In this paper experimental study has been carried out in a cascade greenhouse with inner thermal curtain to see the effect of thermal curtain. A thermal model has also been developed to predict the air temperature in a cascade greenhouse. The fan-pad system has been used for ...

Renewable Energy, 2009

In this paper an attempt has been made to develop a simple methodology to calculate embodied ener... more In this paper an attempt has been made to develop a simple methodology to calculate embodied energy of the adobe house at Solar Energy Park, Indian Institute of Technology Delhi, New Delhi (28°35′N, 77°12′E) and its effect on the environment. The special feature of the adobe ...

International Journal of Energy Research, 2006

In the present paper a quasi-steady state mathematical model is developed to predict the outlet a... more In the present paper a quasi-steady state mathematical model is developed to predict the outlet air temperature and monthly heating and cooling potentials of an earth–air heat exchanger. Monthly values of heating and cooling potentials are estimated by rigorous experimentation throughout the year for composite climate of New Delhi. The uncertainty values are calculated for each month; for December the value is 4.9%. It is observed that there is an 8.9 and a 5.9°C temperature rise and fall during winter and summer due to the earth–air heat exchanger buried at a depth of 1.5 m underground. The correlation coefficient, root mean square of percentage deviation, reduced chi-square and mean bias error have been computed for each month. The values are 1, 3.0%, 0.8 and −0.63 for December. Statistical analysis shows that there is fair agreement between theoretical results and experimental observations for each month. Monthly values of heating and cooling potentials have also been predicted for other climatic conditions in India namely Jodhpur, Chennai, Mumbai and Kolkata. Copyright © 2005 John Wiley & Sons, Ltd.

Building and Environment, 2006

In this paper, a thermal model for heating of greenhouse by using different combinations of inner... more In this paper, a thermal model for heating of greenhouse by using different combinations of inner thermal curtain, an earth-air heat exchanger, and geothermal heating has been developed. The analysis incorporates the study of thermal performance of threezone greenhouse. The calculations have been made for a typical production greenhouse in southern part of Argentina; available climatic data has been used. The thermal performance of a greenhouse having thermal curtain and an earth-air heat exchanger has been compared with a greenhouse having thermal curtain and geothermal energy. It is seen that the fluctuations in temperature in the vicinity of plants are comparable in the two cases. From the results, it is seen that an earth-air heat exchanger might prove an alternative source for heating of greenhouse when geothermal energy is not available. It has also been observed that, the increase in temperature of zone I is more for the greenhouse with geothermal than the greenhouse with an earth-air heat exchanger. r

Renewable Energy, 2006

In this paper the thermal model given by Ghoshal and Tiwari has been validated by round-the-year ... more In this paper the thermal model given by Ghoshal and Tiwari has been validated by round-the-year experimental work at IIT Delhi, New Delhi (28° 35′N, 77° 12′E), India. The correlation coefficient and root-mean-square percentage deviation have been computed ...

In the present article, motivated by Jeelani et al. (2013), we have made an attempt to develop an... more In the present article, motivated by Jeelani et al. (2013), we have made an attempt to develop an improved ratio type estimator of population mean using predictive method of estimation by using linear combination of coefficient of skewness and the quartile deviation of auxiliary variable. The mathematical expressions for the bias and mean squared error (MSE) of the proposed estimator up to the first order approximation have been derived. Theoretical efficiency comparison of proposed estimator with the usual ratio estimator, usual product estimator, and Singh et al. (2014) estimators is also made. To amply corroborate the theoretical findings, an empirical study has also been carried out. The suitability of the proposed estimator can be established and appreciated as it has lesser mean squared error, when compared to other widely used estimators.

The present article deals with the predictive estimation of finite population mean using coeffici... more The present article deals with the predictive estimation of finite population mean using coefficient of kurtosis and median of the auxiliary variable under simple random sampling scheme. Motivated by Milton et al. [2017], we have proposed an improved ratio type predictive estimator of finite population mean. Bias and mean squared error (MSE) of the proposed estimator are also obtained up to first order of approximation. Theoretical efficiency comparison of proposed estimator with Bahl and Tuteja [1991] estimator and Singh et al. estimator [2014] has also been carried out. Optimum conditions, under which the proposed estimator performs better than the competing estimators are also derived. To amply corroborate the theoretical findings, an empirical study has also been carried out. The percent relative efficiencies of the proposed estimator over existing estimators have also been obtained. The suitability of the proposed estimator can be established and appreciated as it has lesser mean squared error, when compared to other widely used estimators.

Solar Energy, 2008

In this paper experimental study has been carried out in a cascade greenhouse with inner thermal ... more In this paper experimental study has been carried out in a cascade greenhouse with inner thermal curtain to see the effect of thermal curtain. A thermal model has also been developed to predict the air temperature in a cascade greenhouse. The fan-pad system has been used for ...

Renewable Energy, 2009

In this paper an attempt has been made to develop a simple methodology to calculate embodied ener... more In this paper an attempt has been made to develop a simple methodology to calculate embodied energy of the adobe house at Solar Energy Park, Indian Institute of Technology Delhi, New Delhi (28°35′N, 77°12′E) and its effect on the environment. The special feature of the adobe ...

International Journal of Energy Research, 2006

In the present paper a quasi-steady state mathematical model is developed to predict the outlet a... more In the present paper a quasi-steady state mathematical model is developed to predict the outlet air temperature and monthly heating and cooling potentials of an earth–air heat exchanger. Monthly values of heating and cooling potentials are estimated by rigorous experimentation throughout the year for composite climate of New Delhi. The uncertainty values are calculated for each month; for December the value is 4.9%. It is observed that there is an 8.9 and a 5.9°C temperature rise and fall during winter and summer due to the earth–air heat exchanger buried at a depth of 1.5 m underground. The correlation coefficient, root mean square of percentage deviation, reduced chi-square and mean bias error have been computed for each month. The values are 1, 3.0%, 0.8 and −0.63 for December. Statistical analysis shows that there is fair agreement between theoretical results and experimental observations for each month. Monthly values of heating and cooling potentials have also been predicted for other climatic conditions in India namely Jodhpur, Chennai, Mumbai and Kolkata. Copyright © 2005 John Wiley & Sons, Ltd.

Building and Environment, 2006

In this paper, a thermal model for heating of greenhouse by using different combinations of inner... more In this paper, a thermal model for heating of greenhouse by using different combinations of inner thermal curtain, an earth-air heat exchanger, and geothermal heating has been developed. The analysis incorporates the study of thermal performance of threezone greenhouse. The calculations have been made for a typical production greenhouse in southern part of Argentina; available climatic data has been used. The thermal performance of a greenhouse having thermal curtain and an earth-air heat exchanger has been compared with a greenhouse having thermal curtain and geothermal energy. It is seen that the fluctuations in temperature in the vicinity of plants are comparable in the two cases. From the results, it is seen that an earth-air heat exchanger might prove an alternative source for heating of greenhouse when geothermal energy is not available. It has also been observed that, the increase in temperature of zone I is more for the greenhouse with geothermal than the greenhouse with an earth-air heat exchanger. r

Renewable Energy, 2006

In this paper the thermal model given by Ghoshal and Tiwari has been validated by round-the-year ... more In this paper the thermal model given by Ghoshal and Tiwari has been validated by round-the-year experimental work at IIT Delhi, New Delhi (28° 35′N, 77° 12′E), India. The correlation coefficient and root-mean-square percentage deviation have been computed ...