M. N. Murthy, Sampling theory and methods. Calcutta: Statistical Publishing Society, 1967.
D. Singh and F. S. Chaudhary, Theory and analysis of sample survey designs. New Delhi: New Age International Publisher, 1986.
A. L. Al-Omari, A. A. Jemain, and K. Ibrahim, "New ratio estimators of the mean using simple random sampling and ranked set sampling methods," Revista Investigación Operacional, vol. 30, pp. 97-108, 2009.
C. Kadilar and H. Cingi, "Ratio estimators in simple random sampling," Applied Mathematics and Computation, vol. 151, pp. 893-902, 2004.
C. Kadilar and H. Cingi, "An improvement in estimating the population mean by using the correlation coefficient," Hacettepe Journal of Mathematics and Statistics, vol. 35, pp. 103-109, 2006.
Z. Yan and B. Tian, "Ratio method to the mean estimation using coefficient of skewness of auxiliary variable," ICICA 2010, Part II, CCIS, vol. 106, pp. 103–110, 2010.
J. Subramani, "Generalized modified ratio estimator for estimation of finite population mean," Journal of Modern Applied Statistical Methods, vol. 12, pp. 121-155, 2013.
H. Cingi and C. Kadilar, Advances in sampling theory- ratio method of estimation. Sharjah, United Arab Emirates: Bentham Science Publishers, 2009.
W. G. Cochran, Sampling techniques, 3rd ed. New Delhi, India: Wiley Eastern Limited, 1977.
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J. Subramani , G. Kumarapandiyan , S. Balamurali (2014). Some Modified Linear Regression Type Ratio Estimators for Estimation of Population Mean Using Known Parameters of an Auxiliary Variable. Journal of Building Construction, Planning and Materials Research, 1(1): 28-42. DOI:
The present paper deals with modified linear regression type ratio estimators for estimation of population mean of the study variable when the Kurtosis, Skewness, population correlation coefficient and quartiles of the auxiliary variable are known. The bias and the mean squared error of the proposed estimators are derived and are compared with that of simple random sampling without replacement (SRSWOR) sample mean, the usual ratio estimator and the existing modified linear regression type ratio estimators. As a result, we have derived the conditions for which the proposed estimators perform better than the other existing estimators. Further the performance of the proposed estimators with that of the existing estimators are assessed for a natural population. From the numerical study it is observed that the proposed modified ratio estimators perform better than the existing estimators.
Orientational Effects on Soiling Measurements at the Sheldonian Theatre in Central Oxford, UK
V. Fassina, Stone decay of Venetian monuments in relation to air pollution. Engineering geology of ancient works, monuments and historical sites. Rotterdam: A. A. Balkema, 1988.
G. Lammel and G. Metzig, "Pollutant fluxes onto the façades of a historical monument," Atmospheric Environment, vol. 31, pp. 2249-2259, 1997.
C. M. Grossi and P. Brimblecombe, "Aesthetics of simulated soiling patterns on architecture," Environmental Science and Technology, vol. 38, pp. 3971-3976.
C. I. Davidson, W. Tang, S. Finger, V. Etyemezian, M. F. Striegel, and S. I. Sherwood, "Soiling patterns on a tall limestone building: Changes over 60 years," Environmental Science and Technology, vol. 34, pp. 560-565, 2000.
Etyemezian, C. I. Davidson, M. Zufall, W. Dai, S. Finger, and M. Striegel, "Impingement of rain drops on a tall building," Atmospheric Environment, vol. 34, pp. 2399-2412, 2000.
B. Blocken, D. Derome, and J. Carmeliet, "Rainwater runoff from building facades: A review," Building and Environment, vol. 60, pp. 339-361, 2013.
F. Monna, A. Puertas, F. Lévêque, R. Losno, G. Fronteau, B. Marin, J. Dominik, C. Petit, B. Forel, and C. Chateau, "Geochemical records of limestone façades exposed to urban atmospheric contamination as monitoring tools?," Atmospheric Environment, vol. 42, pp. 999-1011, 2008.
P. Brimblecombe and C. M. Grossi, "Millennium-long recession of limestone facades in London," Environmental Geology, vol. 56, pp. 463-471, 2008.
W. J. Arkell, Oxford stone. London: Faber and Faber, 1947.
Oxfordshire County Council, Oxfordshire's environment: Environmental monitoring report. Oxford: Department of Planning and Property Services, Oxfordshire County Council, 1995.
S. J. Antill and H. A. Viles, Deciphering the impacts of traf?c on stone decay in Oxford: Some preliminary observations from old limestone walls. Stone weathering and atmospheric pollution network: Aspects of stone weathering, decay and conservation, 1997. Aberdeen: Imperial College Press, 1998.
A. Török, Oolitic limestone in a polluted atmospheric environment in Budapest: Weathering phenomena and alterations in physical properties. Natural stone, weathering phenomena, conservation strategies and case studies vol. 205. London: Geological Society, Special Publications, 2002.
M. J. Thornbush and H. A. Viles, Surface soiling pattern detected by integrated digital photography and image processing of exposed limestone in Oxford, England. Air pollution and cultural heritage. London: A. A. Balkema Publishers, 2004.
M. Thornbush and H. Viles, "Changing patterns of soiling and microbial growth on building stone in Oxford, England after implementation of a major traffic scheme," Science of the Total Environment, vol. 367, pp. 203-211, 2006.
M. Thornbush, "Digital photography used to quantify the greening of North-facing walls along broad street in central Oxford, UK/ L’utilisation de la photographie numérique pour quantifier le verdissement de la façade septentrionale longeant Broad Street dans le centre d’Oxford, Royaume-Uni," Géomorphologie: Relief, Processus, Environnement, vol. 2, pp. 111-118, 2013.
M. J. Thornbush and S. E. Thornbush, Photographs across time. Sharjah: Bentham Science Publishers, In press, 2014.
P. Brimblecombe and C. M. Grossi, "Aesthetic thresholds and blackening of stone buildings," Science of the Total Environment, vol. 349, pp. 175-189, 2005.
M. J. Thornbush, "A soiling index based on quantitative photography at Balliol college in central Oxford, UK," Journal of Earth, Ocean and Atmospheric Sciences, vol. 1, pp. 1-15, 2014.
M. J. Thornbush, Measurements of soiling and colour change using outdoor rephotography and image processing in adobe photoshop along the Southern façade of the Ashmolean Museum, Oxford. Limestone in the built environment: Present-day challenges for the preservation of the past vol. 331. London: Geological Society, Special Publications, 2010.
K. Hall, "Natural building stone composed of light-transmissive minerals: Impacts on thermal gradients, weathering and microbial colonization. A preliminary study, tentative interpretations, and future directions," Environmental Earth Sciences, vol. 62, pp. 289-297, 2011.
B. Pereira De Oliveira, J. M. De La Rosa, A. Z. Miller, C. Saiz-Jimenez, A. Gómez-Bolea, M. A. Sequeira Braga, and A. Dionísio, "An integrated approach to assess the origins of black films on a granite monument," Environmental Earth Sciences, vol. 63, pp. 1677-1690, 2011.
R. Fort, M. Alvarez de Buergo, E. Perez-Monserrat, and M. J. Varas, "Characterisation of monzogranitic batholiths as a supply source for heritage construction in the Northwest of Madrid," Engineering Geology, vol. 115, pp. 149-157, 2010.
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Mary J. Thornbush (2014). Orientational Effects on Soiling Measurements at the Sheldonian Theatre in Central Oxford, UK. Journal of Building Construction, Planning and Materials Research, 1(1): 1-27. DOI:
A digital camera was used to photograph images around the Sheldonian Theatre, which is a semicircular building located in central Oxford, UK. Close-up images included a color chart for lightness and chromatic calibration across images taken between 10:00 and 13:00 in the spring in order to obtain comparative brightness levels for vertical limestone surfaces around this historical building. A digital light (Lux) meter was also employed in this study to capture variations in incoming sunlight onto building walls at ground-level. The outdoor integrated digital photography and image processing (O-IDIP) method was used, focusing on orientational effects on the lightness and coloration of surfaces. Images in Lab Color were calibrated based on a 3-point (black-white and green-red) procedure. The results convey the brightest surfaces on average to be west-facing. Conversely, the most variation in the means was evident on the east-facing side of the building and lowest on the west wall. These variances convey the effects of piecemeal maintenance of the building, so that on the same wall the lowest and greatest values of calibrated % Mean L appear. Soiling patterns are affected by microclimatic effects, with wind-driven rain in Oxford coming predominantly from the southwest, affecting buildings differently at the regional to local scale. This means that south- and west-facing walls may be relatively more rainwashed than north- and east-facing walls, which could complicate the results as a confounding variable acting on the degree of soiling and surface brightness. However, Lux meter readings helped to clarify this complication, showing the least illumination on west- and south-facing building walls. The study, hence, contributes to disentangling between and elucidating outdoor lighting conditions and soiling patterns imposed by microclimatic effects on vertical (limestone) surfaces, such as this historical building exterior, where the brightest illuminated surfaces are not west-and south-facing, but rather east- and north-facing. It thereby quantifies the extent of brightness ranges in soiling patterns created by rainwashing (exposure versus sheltering) effects. Finally, the 3-point calibration procedure now integrates chroma as well as brightness and contrast adjustments, allowing for the outdoor measurement of areal chromatic change on building exteriors. The building walls in this study are mainly Slightly Dark and only a minority are actually classifiable as Dark.
This study contributions to the quantification of building soiling in polluted (urban) environments. Rather than using point-source measurements, the O-IDIP allows for the areal quantification of color. Its application allows for the differentiation of microclimatic effects on outdoor lighting (orientational effects) and surface brightness and coloration.