Malaysian Peninsular Research Articles

Rainfall Pattern Forecasting Using Novel Hybrid Intelligent Model Based ANFIS-FFA

In this study, a new hybrid model integrated adaptive neuro fuzzy inference system with Firefly Optimization algorithm (ANFIS-FFA), is proposed for forecasting monthly rainfall with one-month lead time. The proposed ANFIS-FFA model is compared with standard ANFIS model, achieved using predictor-predictand data from the Pahang river catchment located in the Malaysian Peninsular. To develop the predictive models, a total of fifteen years of data were selected, split into nine years for training and six years for testing the accuracy of the proposed ANFIS-FFA model. To attain optimal models, several input combinations of antecedents’ rainfall data were used as predictor variables with sixteen different model combination considered for rainfall prediction. The performances of ANFIS-FFA models were evaluated using five statistical indices: the coefficient of determination (R 2 ), Nash-Sutcliffe efficiency (NSE), Willmott’s Index (WI), root mean square error (RMSE) and mean absolute error (MAE). The results attained show that, the ANFIS-FFA model performed better than the standard ANFIS model, with high values of R 2 , NSE and WI and low values of RMSE and MAE. In test phase, the monthly rainfall predictions using ANFIS-FFA yielded R 2 , NSE and WI of about 0.999, 0.998 and 0.999, respectively, while the RMSE and MAE values were found to be about 0.272 mm and 0.133 mm, respectively. It was also evident that the performances of the ANFIS-FFA and ANFIS models were very much governed by the input data size where the ANFIS-FFA model resulted in an increase in the value of R 2 , NSE and WI from 0.463, 0.207 and 0.548, using only one antecedent month of data as an input (t-1), to almost 0.999, 0.998 and 0.999, respectively, using five antecedent months of predictor data (t-1, t-2, t-3, t-6, t-12, t-24). We ascertain that the ANFIS-FFA is a prudent modelling approach that could be adopted for the simulation of monthly rainfall in the present study region.

Knowledge of warfarin therapy among patients attending Warfarin Clinic at a Public Hospital in Northern part of Malaysian Peninsular

Background: Patient's knowledge of anticoagulation therapy is important to achieving and maintaining optimal therapy outcome as well as reducing adverse events. The aim of this study was to assess knowledge of warfarin therapy among patients attending Warfarin Clinic at a public hospital. Materials and Method: A cross-sectional survey of 128 patients was conducted at a Warfarin Clinic. Face to face interviews were conducted, using standard questionnaires to determine demographic characteristics and knowledge of warfarin therapy. Results: The mean age of participants was 50.5 years. Majority of patients were male (56.2%), Malays (46.89%) and married (78.1%). A large proportion of patients had only primary (33.6%) and secondary school education (43.0%). The result indicates almost all patients know the indication (95.8%) and dosage (92.2%) of warfarin. In addition, 89.1% of patients know what to do in case of a missed dose. However, more than half of participants do not know the consequence of missing a dose. Most patients know the purpose of INR monitoring and the consequence of INR value above or below the therapeutic range. There were only 42.2% of the patients who know the frequency of INR monitoring. Knowledge of drug interaction indicates more than 50% of patients possess knowledge of warfarin-alcohol, warfarin-vitamin, warfarin-OTC and warfarin-food interaction. There were 64.1% of patients who know when to seek immediate medical attention and 56.3% who are aware of side effect monitoring. Categorization of knowledge level shows 41.4% of patients have good level of knowledge about anticoagulation therapy. However, only 33.6% of patients have excellent knowledge while 1.6% of patients were found to have poor knowledge of warfarin therapy. Conclusion: It can be concluded majority of patients attending warfarin clinic have insufficient knowledge about warfarin therapy.

Local intraplate earthquake considerations for Singapore

The current National Annex for Singapore to Eurocode 8 is primarily to address distant hazards from Sumatra and is not intended to provide coverage for potential local intraplate hazards. The latter type of hazards has safety implications on low-rise structures including many of the aged building construction. It is argued that the absence of local seismic activities in the recorded history within the Malaysian peninsular cannot be used as evidence to justify the assumption that its level of potential local hazards is any lower than other intraplate regions such as Australia, Southern India, and Central and Eastern United States, because of the relative smallness of the landmass of the peninsular. This paper presents a response spectrum model for intraplate earthquakes using relevant data from other regions around the world as opposed to relying on very limited amount of data from regional monitoring. Finally, a response spectrum model that takes into account potential threats from both distant and local ...

Contamination of diuron in coastal waters around Malaysian Peninsular

The use of antifouling paints to the boats and ships is one among the threats facing coastal resources including coral reefs in recent decades. This study reports the current contamination status of diuron and its behaviour in the coastal waters of Malaysia. The maximum concentration of diuron was 285ng/L detected at Johor port. All samples from Redang and Bidong coral reef islands were contaminated with diuron. Temporal variation showed relatively high concentrations but no significant difference (P>0.05) during November and January (North-East monsoon) in Klang ports (North, South and West), while higher levels of diuron were detected during April, 2012 (Inter monsoon) in Kemaman, and Johor port. Although no site has shown concentration above maximum permissible concentration (430ng/L) as restricted by the Dutch Authorities, however, long term exposure studies for environmental relevance levels of diuron around coastal areas should be given a priority in the future.

Impacts of the 2004 Tsunami: Preparedness of the Malaysian Coastal Communities

The Indian Ocean tsunami of 26th December 2004 unleashed catastrophe in many nations including coastal communities located along the west-coast of Malaysian Peninsular. The goal of this study is to explore the impact of the tsunami to the preparedness of the affected coastal communities. Data was collected through questionnaire, interviews, documents analysis and field observations. It was found that the 2004 tsunami disaster has left a significant mark on Malaysia's and the world's disaster management landscape but the tragedy has also heightened disaster awareness and steps must be taken to ensure vulnerable communities are well-equipped to face any eventualities.

Standardization and Bioassays Characterization on Malaysian herb, Ficus deltoidea Jack

Standardization of herbal materials based on their chemical and biological profile is an important prerequisite for development of herbal product. Proper identification of the source plant with related biological property is the main issue encountered in herbal standardization. Ficus deltoidea Jack (FD) is a South East Asian native plant traditionally used to treat several diseases. Pharmacological data showed that this plant exhibited good antioxidant, anti-diabetic and anti-inflammatory properties. However, there are confusion on the identification of plant material as FD occur at least in eight varieties namely Ficus deltoidea var. deltoidea, var. trengganuensis, var. kunstleri, var. montleyana, var. intermedia, var. bornensis, var. bilobata and var. angustifolia. Since reports on pharmacological and chemical studies were not at the varietal level, it is difficult to identify the best variety to be commercialized. In order to determine the most biological active variety, eight varieties of FD were collected from several localities around Malaysian Peninsular and Borneo and subjected for HPTLC and HPLC fingerprinting analysis using biologically active marker compounds, vitexin and isovitexin. HPTLC chromatograms indicated significant differences in chemical composition among varieties with var. deltoidea and var. trengganuensis possess the most chemical content. Both varieties also contain the most phenolic compounds based on Ferric-chloride assay. The concentration of marker compounds also significantly different among varieties which showed that var. trengganuensis contains the highest concentration of both markers. In vitro antioxidant and anti-diabetic data revealed the differences in biological activities which var. trengganuensis and var. motleyana showed a comparable strongest activity compared to other varieties. Finding from this study will assist the selection of the best variety to be developed as herbal product.

Antibacterial and Antioxidant Activities from the Extracts of the Leaves of Phoebe Grandis (Nees) Merr

The genus of Phoebe of family Lauraceae is found the most abundance in Borneo and the Malaysian Peninsular. Phoebe grandis locally known as ‘medang ketanah or tanah.’ The isolation of three compounds lysicamine (1), N-methyllitsericinone (2), N-methyllitsericine (3) were evaluated against selected pathogenic bacteria which are Staphylococcus epidermidis, Staphylococcus aureus, Bacillus, Pasteurella multocida and Enterobacter cloacae. Lysicamine (1) showed strong antibacterial activity against all bacteria strains. (The result will be highlighted during the presentation). Meanwhile, the biological screening of antioxidant activities were determined using DPPH scavenging and ferric reducing antioxidant power (FRAP) assays. The present study of the hexane, dichloromethane, methanol and alkaloid extracts from the leaves of Phoebe grandis showed these extracts had good scavenging activity. The antioxidant activity gave potent result to the alkaloids extract compared to other extracts.

Optimal Thyristor Control Series Capacitor Neuro-Controller for Damping Oscillations

This study applies a neural-network-based optimal TCSC controller for damping oscillations. Optimal neural network controller is related to model-reference adaptive control, the network controller is developed based on the recursive “pseudo-linear regression. Problem statement: The optimal NN controller is designed to damp out the low frequency local and inter-area oscillations of the large power system. Approach: Two multilayer-perceptron neural networks are used in the design-the identifier/model network to identify the dynamics of the power system and the controller network to provide optimal damping. By applying this controller to the TCSC devices the damping of inter-area modes of oscillations in a multi-machine power system will be handled properly. Results: The effectiveness of the proposed optimal controller is demonstrated on two power system problems. The first case involves TCSC supplementary damping control, which is used to provide a comprehensive evaluation of the learning control performance. The second case aims at addressing a complex system to provide a very good solution to oscillation damping control problem in the Southern Malaysian Peninsular Power Grid. Conclusion: Finally, several fault and load disturbance simulation results are presented to stress the effectiveness of the proposed TCSC controller in a multi-machine power system and show that the proposed intelligent controls improve the dynamic performance of the TCSC devices and the associated power network.

Spatio-temporal characteristics of PM10 concentration across Malaysia

The recurrence of forest fires in Southeast Asia and associated biomass burning, has contributed markedly to the problem of trans-boundary haze and the long-range movement of pollutants in the region. Air pollutants, specifically particulate matter in the atmosphere, have received extensive attention, mainly because of their adverse effect on people's health. In this study, the spatial and temporal variability of the PM10 concentration across Malaysia was analyzed by means of the rotated principal component analysis. The results suggest that the variability of the PM10 concentration can be decomposed into four dominant modes, each characterizing different spatial and temporal variations. The first mode characterizes the southwest coastal region of the Malaysian Peninsular with the PM10 showing a peak concentration during the summer monsoon i.e. when the winds are predominantly southerlies or southwesterlies, and a minimal concentration during the winter monsoon. The second mode features the region of western Borneo with the PM10 exhibiting a concentration surge in August–September, which is likely to be the result of the northward shift of the Inter Tropical Convergence Zone (ITCZ) and the subsequent rapid arrival of the rainy season. The third mode delineates the northern region of the Malaysian Peninsular with strong bimodality in the PM10 concentration. Seasonally, this component exhibits two concentration maxima during the late winter and summer monsoons, as well as two minima during the inter-monsoon periods. The fourth dominant mode characterizes the northern Borneo region which exhibits weaker seasonality of the PM10 concentration. Generally, the seasonal fluctuation of the PM10 concentration is largely associated with the seasonal variation of rainfall in the country. However, in addition to this, the PM10 concentration also fluctuates markedly in two timescale bands i.e. 10–20 days quasi-biweekly (QBW) and 30–60 days lower frequency (LF) band of the intra-seasonal timescales. These intra-seasonal fluctuations show strong seasonality with the largest fraction of variance occurring during the boreal summer and the weakest variance during the winter. Generally, the LF intra-seasonal oscillation is stronger compared to the QBW intra-seasonal band.

Extreme rainfall characteristics for surface slope stability in the Malaysian Peninsular

This paper discusses the results of an investigation on the influence of rainfall intensity and duration on the suction distribution within a soil mass. A series of numerical analyses were conducted on an infinite slope model to simulate the responses of the slope consisting of typical soil types to various rainfall intensities and durations from selected locations in the Malaysian Peninsular. The study showed that the critical duration was governed by three major factors: the saturated permeability of the soil, the geographical location, and the depth of the slip plane. The critical rainfall duration for highly permeable soil was 1 day, while 30 days of antecedent rainfall were required for the stability analysis of a slope made of soil with low saturated permeability. The critical duration of antecedent rainfall in soils with intermediate saturated permeability was found to vary with the rainfall pattern. A chart is proposed to determine the critical duration, critical intensity and critical suction for each type of soil.