Browsing School of Environmental Engineering (Articles) by Subject "Air pollution"

Now showing items 1-3 of 3

    • Estimation of missing values for air pollution data using Interpolation technique 

      Norazian, Mohamed Noor; Mohd Mustafa, Al Bakri Abdullah; Ahmad Shukri, Yahaya; Nor Azam, Ramli (Universiti Malaysia Perlis, 2006)
      Air pollution data such as PM10, sulphur dioxide, ozone and carbon monoxide are usually obtained using automated machines located at different sites. These are usually due to mechanical failure, routine maintenance, changes ...

    • Estimation of missing values in air pollution data using single imputation techniques 

      Norazian, Mohamed Noor; Shukri, Yahaya Ahmad; Azam, Ramli Nor; Mohd. Mustafa Al Bakri, Abdullah (Science Society of Thailand, 2008)
      Air pollution data obtained using automated machines often contain missing values which can cause bias due to systematic differences between observed and unobserved data. We used interpolation and mean imputation techniques ...

    • Mean imputation techniques for filling the missing observations in air pollution dataset 

      Noorazian, Mohamed Noor; Ahmad Shukri, Yahaya, Prof. Madya; Nor Azam, Ramli, Prof. Dr.; Mohd Mustafa Al Bakri, Abdullah (Trans Tech Publications, 2014)
      Almost all real life datasets consist missing values. These are usually due to machine failure, routine maintenance, changes in siting monitors and human error. The occurence of missing values requires special attention ...