Browsing by Author "Muhammad Hisyam Lee"

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    Indeks Pencemaran Udara berdasarkan Kalendar Grafik untuk Pemprofilan Tren Visualisasi dan Analisis
    (Penerbit UKM, 2020) Nur Haizum Abd Rahman; Muhammad Hisyam Lee
    Detection of air quality abnormality is important as an early warning system for air quality control and management. The information can raise citizens’ awareness towards current air quality status. By using time series plot, the data pattern can be identified but not able to exactly determine the abnormality due to overcrowded plot. Therefore, visualization data profiling was presented in this study by using seven years Malaysia daily air pollutant index to improve the detection.
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    Penilaian Prestasi Pendekatan Siri Masa untuk Peramalan Indeks Pencemaran Udara di Johor, Malaysia
    (Penerbit UKM, 2016) Nur Haizum Abd Rahman; Muhammad Hisyam Lee; Suhartono; Mohd Talib Latif
    The air pollution index (API) has been recognized as one of the important air quality indicators used to record the correlation between air pollution and human health. The API information can help government agencies, policy makers and individuals to prepare precautionary measures in order to eliminate the impact of air pollution episodes. This study aimed to verify the monthly API trends at three different stations in Malaysia; industrial, residential and sub-urban areas. The data collected between the year 2000 and 2009 was analyzed based on time series forecasting. Both classical and modern methods namely seasonal autoregressive integrated moving average (SARIMA) and fuzzy time series (FTS) were employed. The model developed was scrutinized by means of statistical performance of root mean square error (RMSE).
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    Spatial distribution of natural γ radiation exposure and its relationship to soil types
    (Springer, 2016) Ahmad Termizi Ramli; Mohammad Syazwan Mohd Sanusi; Muhammad Hisyam Lee; Sallehuddin Sahrone; Nor Zati Hani Abu Hanifah
    An extensive survey of natural γ radiation dose rate levels was measured throughout the Melaka State, Malaysia. The main objective of the present study is to verify the influence of different soil types γ radiation exposures in air using statistical analyses. One-way analysis of variances ANOVA and post hoc test using Fisher’s least significant difference (LSD) were used to test the probability of significance difference between the dose rates and soil types. The survey involved 541 measurement points of terrestrial gamma radiation dose rates in an area of 1650 km2 which covers five major soil groups based on six FAO/UNESCO soil orders.