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The Eurasia Proceedings of Science Technology Engineering and Mathematics
The Eurasia Proceedings of Science Technology Engineering and Mathematics
Rainfall is an important factor in civil engineering as it affects the design of hydraulic struct... more Rainfall is an important factor in civil engineering as it affects the design of hydraulic structures, bridges and culverts, canals, storm water sewers, road drainage systems, etc. This paper presents the statistical analysis of 30-year rainfall data collected at eight rainfall stations within the Langat River Basin. Ten plotting position methods were utilised to evaluate the return period of annual rainfall. The yearly rainfall was computed to assess the variability of rainfall based on the determined results; the pattern of rainfall is irregular. Weibull Distribution from Plotting Position methods is found to best fit the annual rainfall data. The findings provide the insights for determining the correct commencement and cessation of monsoon results, which have the effect on land utilisation, flood forecasting and emergency planning. This analysis contributes to water management, water resource planners, farmers, and urban engineers to evaluate the availability of water and develop the storage accordingly.
The Eurasia Proceedings of Science Technology Engineering and Mathematics
Biofouling is one of the primary hurdles unavoidable in the operation of membrane bioreactors. Th... more Biofouling is one of the primary hurdles unavoidable in the operation of membrane bioreactors. The distribution and roles of cake layers in biofouling have been extensively investigated. Transparent exopolymer particles perform a variety of biological functions, which has a substantial impact on particle distribution as it is present ubiquitously in wastewater. Fouling was seen in this investigation to be the result of the deposition of particulate, colloidal or soluble material within the pores or on the membrane surface. The distribution of biofouling on the membrane surface and in the cake layer was investigated using a membrane bioreactor operating at a membrane flux of 10 L/m 2 h, with the initial concentration of mixed liquor suspended solids of 10g/L treating actual sewage. Confocal laser scanning microscope and field emission scanning electron microscope were employed to divulge the mechanism of fouling in the membrane bioreactor. The transmembrane pressure and membrane flux were observed throughout the membrane operation. As the fouling progressed, a membrane sample was taken and examined. During the membrane bioreactor operation process, the outcome of the fluorescent staining of the foulant was depicted. In the initial stage, humic-like substances contribute to membrane fouling. Highly concentrated protein-like compounds dominated the fouling behavior. Over time, a protein-controlling cake layer was formed. It can be concluded that in the long-term stage, protein was significantly linked with irreversible fouling.
International journal of health sciences, 2022
Poor performance of students in Engineering Mathematics can be overcome by introducing innovative... more Poor performance of students in Engineering Mathematics can be overcome by introducing innovative way in teaching. Teaching Engineering Mathematics via lab has been proven to boost the students’ performance in Engineering Mathematics. Thus, the objective of this study is to conduct a pilot test to evaluate students’ knowledge prior to introducing lab session to engineering undergraduates. A pilot test was conducted on third semester students in engineering faculty. A total of 35 students from Electrical Engineering, Civil Engineering and Chemical Engineering participated in the pilot test. Six course outcomes are chosen from Vector Calculus, Linear Algebra and Ordinary Differential Equations subjects. Six subjective questions were prepared and the questions were validated by three internal experts. The results of the test were analyzed against Rasch model. The item reliability 0.69 shows an average difficulty of spread of the pilot test questions. Furthermore, the summary statistics...
JOURNAL OF MECHANICS OF CONTINUA AND MATHEMATICAL SCIENCES, 2020
Flash flood happens when the drainage or river could not cope with the sudden increase in rainfal... more Flash flood happens when the drainage or river could not cope with the sudden increase in rainfall volume. In Malaysia, flash flood often occurs in the developed cities such as Kuala Lumpur and Kuantan. Water yield or reservoir storage is the collection and storing of water during high-water period and to be used during low-water period. It preserves the excess water where or else it will result in water wastage and potentially cause a flood disaster to happen. The capacity of the water yield has to be sufficiently large to sustain the amount of increasing rain water without overflowing. The study aims to investigate the rainfall runoff relationship of Sungai Pahang River. Study period of this hydrological modelling was selected from year January 2013 to December 2017. The hydrological modelling using HEC-HMS of Sungai Pahang resulted with a correlation of 0.65 and Nash-Sutcliffe coefficient of 0.41. Clark unit hydrograph in transform method and recession constant in baseflow method have great impact on the simulation result.
International Journal of Research in Engineering and Technology, Jun 25, 2015
Rainfall amounts and water surface elevation are considered as one of the most important climatic... more Rainfall amounts and water surface elevation are considered as one of the most important climatic parameters. Because these two parameters will have a direct impact on water resources management decisions such as meet the water needs and prevent flooding. But in some cases, for some reason all time series data are not fully recorded. To fill the gaps in the data, several interpolation methods currently used. One of these methods is regression analysis as a statistical method. By using regression, we can determine the mathematical relationship coefficients between inputs and outputs. By achieving the equation, we can obtain the unknown quantities. In this research, the daily data between 2005 to 2015 for 5 Rain-gauge stations and 3 elevation measurement of water surface stations in the Klang River Basin were used. The main goal was to find the missing value of the water level in the mentioned three stations by rainfall and water level data. To evaluate the obtained results, Multiple R, R 2 , and Standard Error were used. The results indicate that the standard error in normalized data was less than the regular data.
Objectives: Prevalence odds ratio (POR) is commonly used as a surrogate for relative risk (RR) in... more Objectives: Prevalence odds ratio (POR) is commonly used as a surrogate for relative risk (RR) in crosssectional studies. When prevalences are high, POR may be a poor approximation for RR. Prevalence ratios (PRs) are more easily interpretable when evaluating exposure effects. Our objectives were to compare estimates of PRs and corresponding 95% confidence intervals (CIs) using three different statistical methods on a real data set, furthermore, to report possible practical problems in applying the methods. Methods: Two statistical methods were compared: log-binomial regression and Cox regression. We examined selected high prevalence symptoms: headache, tingling of limbs, and breathing difficulty, and their association with solvent-exposed work tasks in 164 Hebron shoe factory workers. Results: The two methods estimated identical crude point PR estimates and quite similar adjusted estimates. CIs were wider in Cox regression than in log-binominal regression, as exemplified by adjusted estimates for the association between participation in cleaning tasks and tingling of limbs in log-binomial regression (PR=1.78; CI=1.25-2.54), Cox regression (PR=1.76; CI=1.01-3.06). When we used Cox regression with robust variance we obtained narrower CIs (PR=1.76; CI=1.19-2.60). In the log-binomial regression analysis we had to exclude a few subjects with a predicted risk exceeding one. Conclusions: Log-binomial regression is appropriate from a theoretical viewpoint. However, some individuals had a predicted risk larger than one, which caused the computation to abort. Cox regression could produce heavy ties when adjusted for confounders and yielded rather wide CIs, however, by using robust variance we will obtain narrow CIs. In conclusion, the two suggested methods have certain limitations and difficulties. However, Cox regression encountered less serious problems than in the other methods, and is also widely available.
The Eurasia Proceedings of Science Technology Engineering and Mathematics
The Eurasia Proceedings of Science Technology Engineering and Mathematics
Rainfall is an important factor in civil engineering as it affects the design of hydraulic struct... more Rainfall is an important factor in civil engineering as it affects the design of hydraulic structures, bridges and culverts, canals, storm water sewers, road drainage systems, etc. This paper presents the statistical analysis of 30-year rainfall data collected at eight rainfall stations within the Langat River Basin. Ten plotting position methods were utilised to evaluate the return period of annual rainfall. The yearly rainfall was computed to assess the variability of rainfall based on the determined results; the pattern of rainfall is irregular. Weibull Distribution from Plotting Position methods is found to best fit the annual rainfall data. The findings provide the insights for determining the correct commencement and cessation of monsoon results, which have the effect on land utilisation, flood forecasting and emergency planning. This analysis contributes to water management, water resource planners, farmers, and urban engineers to evaluate the availability of water and develop the storage accordingly.
The Eurasia Proceedings of Science Technology Engineering and Mathematics
Biofouling is one of the primary hurdles unavoidable in the operation of membrane bioreactors. Th... more Biofouling is one of the primary hurdles unavoidable in the operation of membrane bioreactors. The distribution and roles of cake layers in biofouling have been extensively investigated. Transparent exopolymer particles perform a variety of biological functions, which has a substantial impact on particle distribution as it is present ubiquitously in wastewater. Fouling was seen in this investigation to be the result of the deposition of particulate, colloidal or soluble material within the pores or on the membrane surface. The distribution of biofouling on the membrane surface and in the cake layer was investigated using a membrane bioreactor operating at a membrane flux of 10 L/m 2 h, with the initial concentration of mixed liquor suspended solids of 10g/L treating actual sewage. Confocal laser scanning microscope and field emission scanning electron microscope were employed to divulge the mechanism of fouling in the membrane bioreactor. The transmembrane pressure and membrane flux were observed throughout the membrane operation. As the fouling progressed, a membrane sample was taken and examined. During the membrane bioreactor operation process, the outcome of the fluorescent staining of the foulant was depicted. In the initial stage, humic-like substances contribute to membrane fouling. Highly concentrated protein-like compounds dominated the fouling behavior. Over time, a protein-controlling cake layer was formed. It can be concluded that in the long-term stage, protein was significantly linked with irreversible fouling.
International journal of health sciences, 2022
Poor performance of students in Engineering Mathematics can be overcome by introducing innovative... more Poor performance of students in Engineering Mathematics can be overcome by introducing innovative way in teaching. Teaching Engineering Mathematics via lab has been proven to boost the students’ performance in Engineering Mathematics. Thus, the objective of this study is to conduct a pilot test to evaluate students’ knowledge prior to introducing lab session to engineering undergraduates. A pilot test was conducted on third semester students in engineering faculty. A total of 35 students from Electrical Engineering, Civil Engineering and Chemical Engineering participated in the pilot test. Six course outcomes are chosen from Vector Calculus, Linear Algebra and Ordinary Differential Equations subjects. Six subjective questions were prepared and the questions were validated by three internal experts. The results of the test were analyzed against Rasch model. The item reliability 0.69 shows an average difficulty of spread of the pilot test questions. Furthermore, the summary statistics...
JOURNAL OF MECHANICS OF CONTINUA AND MATHEMATICAL SCIENCES, 2020
Flash flood happens when the drainage or river could not cope with the sudden increase in rainfal... more Flash flood happens when the drainage or river could not cope with the sudden increase in rainfall volume. In Malaysia, flash flood often occurs in the developed cities such as Kuala Lumpur and Kuantan. Water yield or reservoir storage is the collection and storing of water during high-water period and to be used during low-water period. It preserves the excess water where or else it will result in water wastage and potentially cause a flood disaster to happen. The capacity of the water yield has to be sufficiently large to sustain the amount of increasing rain water without overflowing. The study aims to investigate the rainfall runoff relationship of Sungai Pahang River. Study period of this hydrological modelling was selected from year January 2013 to December 2017. The hydrological modelling using HEC-HMS of Sungai Pahang resulted with a correlation of 0.65 and Nash-Sutcliffe coefficient of 0.41. Clark unit hydrograph in transform method and recession constant in baseflow method have great impact on the simulation result.
International Journal of Research in Engineering and Technology, Jun 25, 2015
Rainfall amounts and water surface elevation are considered as one of the most important climatic... more Rainfall amounts and water surface elevation are considered as one of the most important climatic parameters. Because these two parameters will have a direct impact on water resources management decisions such as meet the water needs and prevent flooding. But in some cases, for some reason all time series data are not fully recorded. To fill the gaps in the data, several interpolation methods currently used. One of these methods is regression analysis as a statistical method. By using regression, we can determine the mathematical relationship coefficients between inputs and outputs. By achieving the equation, we can obtain the unknown quantities. In this research, the daily data between 2005 to 2015 for 5 Rain-gauge stations and 3 elevation measurement of water surface stations in the Klang River Basin were used. The main goal was to find the missing value of the water level in the mentioned three stations by rainfall and water level data. To evaluate the obtained results, Multiple R, R 2 , and Standard Error were used. The results indicate that the standard error in normalized data was less than the regular data.
Objectives: Prevalence odds ratio (POR) is commonly used as a surrogate for relative risk (RR) in... more Objectives: Prevalence odds ratio (POR) is commonly used as a surrogate for relative risk (RR) in crosssectional studies. When prevalences are high, POR may be a poor approximation for RR. Prevalence ratios (PRs) are more easily interpretable when evaluating exposure effects. Our objectives were to compare estimates of PRs and corresponding 95% confidence intervals (CIs) using three different statistical methods on a real data set, furthermore, to report possible practical problems in applying the methods. Methods: Two statistical methods were compared: log-binomial regression and Cox regression. We examined selected high prevalence symptoms: headache, tingling of limbs, and breathing difficulty, and their association with solvent-exposed work tasks in 164 Hebron shoe factory workers. Results: The two methods estimated identical crude point PR estimates and quite similar adjusted estimates. CIs were wider in Cox regression than in log-binominal regression, as exemplified by adjusted estimates for the association between participation in cleaning tasks and tingling of limbs in log-binomial regression (PR=1.78; CI=1.25-2.54), Cox regression (PR=1.76; CI=1.01-3.06). When we used Cox regression with robust variance we obtained narrower CIs (PR=1.76; CI=1.19-2.60). In the log-binomial regression analysis we had to exclude a few subjects with a predicted risk exceeding one. Conclusions: Log-binomial regression is appropriate from a theoretical viewpoint. However, some individuals had a predicted risk larger than one, which caused the computation to abort. Cox regression could produce heavy ties when adjusted for confounders and yielded rather wide CIs, however, by using robust variance we will obtain narrow CIs. In conclusion, the two suggested methods have certain limitations and difficulties. However, Cox regression encountered less serious problems than in the other methods, and is also widely available.