PM10 analysis for three industrialized areas using extreme value

One of the concerns of the air pollution studies is to compute the concentrations of one or more pollutants’ species in space and time in relation to the independent variables, for instance emissions into the atmosphere, meteorological factors and parameters. One of the most significant statistical disciplines developed for the applied sciences and many other disciplines for the last few decades is the extreme value theory (EVT). This study assesses the use of extreme value distributions of the two-parameter Gumbel, two and three-parameter Weibull, Generalized Extreme Value (GEV) and two and three-parameter Generalized Pareto Distribution (GPD) on the maximum concentration of daily PM10 data recorded in the year 2010 - 2012 in Pasir Gudang, Johor; Bukit Rambai, Melaka; and Nilai, Negeri Sembilan. Parameters for all distributions are estimated using the Method of Moments (MOM) and Maximum Likelihood Estimator (MLE). Six performance indicators namely; the accuracy measures which include predictive accuracy (PA), coefficient of determination (R2), Index of Agreement (IA) and error measures that consist of Root Mean Square Error (RMSE), Mean Absolute Error (MAE) and Normalized Absolute Error (NAE) are used to find the goodness-of-fit of the distribution. The best distribution is selected based on the highest accuracy measures and the smallest error measures. The results showed that the GEV is the best fit for daily maximum concentration for PM10 for all monitoring stations. The analysis also demonstrates that the estimated numbers of days in which the concentration of PM10 exceeded the Malaysian Ambient Air Quality Guidelines (MAAQG) of 150 mg/m3 are between ½ and 1½ days

Penggunaan Model Regresi Linear Dalam Kejuruteraan.

Kertas kerja ini membincangkan pengalaman penulis menggunakan kaedah regresi linear untuk menyelesaikan beberapa masalah dalam bidang kejuruteraan awam. Masalah pertama yang dibincangkan ialah untuk melihat kadar penjanaan perjalanan bagi guna tanah di Malaysia. Masalah kedua ialah untuk meramal kedalaman keruk disekitar pier

Modeling The Fiuctuational And Transformation Characteristics Of Peak Ground Level Ozone in Malaysian Ambient Air

Ground level ozone (O3) is a noxious air pollutant that Imposed adverse effect to human health, crop yield and the environment. Hence, it is important to understand their fluctuation and transformation characteristic which is still regarded at its infancy stage in Malaysia to properly design abatement and control strategies. Therefore, this study aimed to Investigate the characteristics of O3 fluctuation and transformation from its precursors as well as to introduce the critical conversion point (COP) of O3 formation. Next hour O3 prediction models during daily, daytime, nighttime and critical conversion time were also developed using multiple linear regression and principal component regression to predict O3 concentrations in different group of monitoring stations. This study consists of 18 areas across Malaysia from 1999 to 2010. Although an ovenwhelming majority of the recorded data are below the prescribed levels in the Malaysian Ambient Air Quality Guidelines, total of 1,988 hour of exceedences have been recorded with majority contributed by Shah Alam. O3 diurnal cycles suggest a unimodal peak between 12 pm to 4 pm, while minimum concentration is consistently measured on 8 am. Results of PCA showed the contributions to O3 variation by NO2, NO, T and UVB is up to 80%, whereas the composite diurnal plots confirmed that variation is highly depend on NO2 and NO concentrations. The CCP of O3 formation were identified to occur in between 8 am to 11 am. MLR model based on cluster group during daily exhibited optimal performance in terms of coefficient of determination, prediction accuracy, and index of agreement with values of 0.9351, 0.9671 and 0.9831, respectively. Although the optimal model was during daily, the developed models using critical conversion time were more consistent with minimal differences between MLR and PGR in terms of error and accuracy. Effective ground level ozone control, need strategic, systematic and concerted efforts amongenvironmental related agencies in Malaysi

Investigation And Modelling Of Particulate Matter During Haze Events In 1997,2004,2005.

Haze events occurred in Malaysia almost every year since more than two decades. These events were usually accompanied with high PM1Q concentrations which can last longer than three days. This study attempt to characterized the years with haze events systematically by fitting the monitoring records into three distributions that were reported to have dealt with extreme events especially those related to air pollutions studies

A Framework For Monitoring And Modelling Of Btex In Various Development Statuses In Penang, Malaysia.

The development and urbanization process in Malaysia are believed to contribute to the deterioration of air quality. The rapid growth of the Malaysian economy lead to the increase of motor vehicles ownership, in 2006, there 6.91 million registered cars running on the roads in Malaysia. Benzene, Toluene, Ethylbenzene and Xylene (BTEX) form an important group of aromatic Volatile Organic Compounds (VOCs), emitted mainly from cars, where BTEX is a known carcinogenic

Statistical evaluation of pre-selection criteria for industrialized building system (IBS)

The Malaysian government has endorsed the use of an industrialized building system (IBS) in domestic projects. These have shifted the focus of the nation's construction industry towards mass production and modular products. A proper study on site selection criteria for new IBS precast manufacturing sites has now become essential. The preliminary study in this research determines the IBS precast manufacturing site selection criteria from literature reviews. Questionnaires pertaining to IBS acceptance and preference criteria were send to manufacturers, policymakers, academicians and contractors. The outcome analyses the respondents’ view towards 15 site selection criteria. The result from the ANOVA statistical test indicates that most respondents agreed with the selected criteria except political and regulation criteria, urban requirement criteria, and personal criteria. However, there is a significant difference within the opinions of the contractors and manufacturers sector. Likewise, the mean ranking analysis of criteria shows significant difference in their preferences. The ideal rank of criteria preferred by the correspondents are costs, transportation and optimum distance, land sites, resources and utilization, infrastructures, economy markets, labour, inter-industry linkage, environmental risk, competition, personal, population, capacity, political and regulatory, and urban criteria

Diurnal fluctuations of ozone concentrations and its precursors and prediction of ozone using multiple linear regressions

The chemical reaction of pollutants emitted into the atmosphere leads to a variety of oxidized products, which are commonly referred to as secondary pollutants. Ground level ozone is a known secondary photochemical pollutant of major importance possessing detrimental effects on health, agriculture, natural/urban ecosystems and materials. Ozone (O3) can irritate lung airways and cause inflammation much like sunburn. Hourly and monthly variations of O3 and their precursors – nitrogen oxides (NOx) and meteorological parameters (temperature and wind speed) were presented using time series plots. Possibility of employing multiple linear regression models as a tool for prediction of O3 concentration was also tested. Measurement was performed continuously in 2005 at two sampling stations located in the metropolitan area of Malaysia. Results indicated that the formation of O3 in the study area was influenced by NOx precursors and meteorological conditions. The hourly variation showed maximum O3 concentrations were recorded between 1300 to 1400 hours, while NOx and nitrogen dioxide (NO2) exhibited two maxima, at 0800-1000 and 2000-2100 hours. The daily cycle of highest O3 concentrations were revealed a lower night level and inverse relations between O3 and NOx. This is clear evidence of photochemical formation of O3. Temperature has the highest influence to the high O3 concentration