Displaying publications 1 - 20 of 118 in total

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  1. Geospatial techniques for assessment of bank erosion and accretion in the Marala Alexandria reach of the River Chenab, Pakistan
    M. Hamid Ch, M. Ashraf, Qudsia Hamid, Syed Mansoor Sarwar, Zulfiqar Ahmad Saqib
    Sains Malaysiana, 2017;46:413-420.
    Remote Sensing (RS) and Geographical Information Systems (GIS) are widely used for change detection in rivers caused
    by erosion and accretion. Digital image processing techniques and GIS analysis capabilities are used for detecting
    temporal variations of erosion and accretion characteristics between the years 1999 and 2011 in a 40 km long Marala
    Alexandria reach of River Chenab. Landsat satellite images for the years 1999, 2007 and 2011 were processed to analyze
    the river channel migration, changes in the river width and the rate of erosion and accretion. Analyses showed that the
    right bank was under erosion in both time spans, however high rate of deposition is exhibited in middle reaches. The
    maximum erosion was 1569843 m2
    and 1486160 m2
    along the right bank at a distance of 24-28 km downstream of the
    Marala barrage in the time span of 1999-2007 and 2007-2011, respectively. Along right bank mainly there is trend of
    accretion but erosion is much greater between 20 and 28 km reach. Maximum accretion was 5144584 m2
    from 1999-2007
    and 2950110 m2
    from 2007-2011 on the right bank downstream of the Marala Barrage. The derived results of channel
    migration were validated by comparing with SRTM data to assess the accuracy of image classification. Integration of remote
    sensing data with GIS is efficient and economical technique to assess land losses and channel changes in large rivers.
    Matched MeSH terms: Geographic Information Systems
  2. Fulltext Application of remote sensing instruments in air quality monitoring in Malaysia
    Mohd Muzammil Salahuddin, Zulfa Hanan Ashaari
    The Pertanika Journal of Scholarly Research Reviews, 2017;3(1):93-112.
    MyJurnal
    The use of remote sensing in detecting aerosol or air pollution is not widely applied in Malaysia. The large area of coverage provided by remote sensing satellite may well be the solution to the lack of spatial coverage by the local ground air quality monitoring stations. This article discusses the application of remote sensing instruments in air quality monitoring of Malaysia. The remote sensing data is validated using ground truths either from local ground air monitoring stations or the Aerosol Robotic Network (AERONET). The correlation between remote sensing is relatively good with R from 0.5 to 0.9 depending on the satellite used. The correlation is much improved using the mixed effects algorithm applied on MODIS Aerosol Optical Depth (AOD) data. Accuracy of predicted air quality data by remote sensing is generally tested using the Root Mean Squared Error (RMSE) against the ground truths data. Besides the Geographic Information System (GIS) tools are used in manipulating the data from both remote sensing and ground stations so as to produce meaningful results such as spatio-temporal pattern mapping of air pollution. Overall the results showed that the application of remote sensing instruments in air quality monitoring in Malaysia is very useful and can be improved further.
    Matched MeSH terms: Geographic Information Systems
  3. Fulltext Measuring and mapping urban growth patterns using remote sensing and GIS techniques
    Aburas, Maher Milad, Sabrina Ho Abdullah, Mohammad Firuz Ramli, Zulfa Hanan Ash'aari
    The Pertanika Journal of Scholarly Research Reviews, 2017;3(1):55-69.
    MyJurnal
    Remote sensing and geographic information system techniques are significant and popular approaches that have been used in recent years to measure and map urban growth patterns. This paper primarily aims to provide a basis for a literature review of urban growth measurement and mapping by using different methods. For this purpose, the general characteristics of measuring and mapping urban growth patterns are described and classified. The strengths and weaknesses of the various methods have been identified from an analysis and discussion of the characteristics of the techniques. Results of reviews confirm that combining quantitative and qualitative techniques, such as Shannon approach and change detection, to measure and map urban growth patterns will improve understanding of the phenomenon of urban growth. Moreover, using social and economic data such as population and income data will improve understanding of the relationships between causes and effects. The integration of social and economic factors with quantitative and qualitative techniques will contribute to a perfect evaluation of urban growth patterns and land use changes, taking technical, social, economic, spatial, and temporal factors into account.
    Matched MeSH terms: Geographic Information Systems
  4. Fulltext A Secure Region-Based Geographic Routing Protocol (SRBGR) for Wireless Sensor Networks
    Adnan AI, Hanapi ZM, Othman M, Zukarnain ZA
    PLoS One, 2017;12(1):e0170273.
    PMID: 28121992 DOI: 10.1371/journal.pone.0170273
    Due to the lack of dependency for routing initiation and an inadequate allocated sextant on responding messages, the secure geographic routing protocols for Wireless Sensor Networks (WSNs) have attracted considerable attention. However, the existing protocols are more likely to drop packets when legitimate nodes fail to respond to the routing initiation messages while attackers in the allocated sextant manage to respond. Furthermore, these protocols are designed with inefficient collection window and inadequate verification criteria which may lead to a high number of attacker selections. To prevent the failure to find an appropriate relay node and undesirable packet retransmission, this paper presents Secure Region-Based Geographic Routing Protocol (SRBGR) to increase the probability of selecting the appropriate relay node. By extending the allocated sextant and applying different message contention priorities more legitimate nodes can be admitted in the routing process. Moreover, the paper also proposed the bound collection window for a sufficient collection time and verification cost for both attacker identification and isolation. Extensive simulation experiments have been performed to evaluate the performance of the proposed protocol in comparison with other existing protocols. The results demonstrate that SRBGR increases network performance in terms of the packet delivery ratio and isolates attacks such as Sybil and Black hole.
    Matched MeSH terms: Geographic Information Systems/economics
  5. Spatial Ecology of Asian Water Monitors Adjacent to a Sea Turtle Nesting Beach
    Lei J, Booth DT, Rusli MU, Zhang Z
    Zoolog Sci, 2021 Feb;38(1):1-7.
    PMID: 33639712 DOI: 10.2108/zs200071
    Nest predation is the main cause of hatching failure for many turtle populations. For green turtles (Chelonia mydas) nesting at Chagar Hutang in Redang Island, Malaysia, Asian water monitors (Varanus salvator) are a potential nest predator. However, no studies have documented the space use of this species in coastal habitat adjacent to a sea turtle nesting beach to assess its potential impact on turtle nests. Here, we used Global Positioning System (GPS) data loggers to quantify space use of Asian water monitors in order to establish the extent to which they use sea turtle nesting areas. Asian water monitors had a diurnal activity pattern and spent most of their time in rain forest habitat behind the sea turtle nesting beach. The home range occupied by Asian water monitors varied between 0.015 and 0.198 km2 calculated by the Kernel Brownian Bridge method. The space use patterns of individual Asian water monitors varied between individuals. Two males had relatively small home ranges, whereas one male and the female had a relatively large home range. Because tracked Asian water monitors in this study rarely visited the sea turtle nesting areas, it is probable that only a few individuals are responsible for opening nests.
    Matched MeSH terms: Geographic Information Systems
  6. Spatial effect of new municipal solid waste landfill siting using different guidelines
    Ahmad SZ, Ahamad MS, Yusoff MS
    Waste Manag Res, 2014 Jan;32(1):24-33.
    PMID: 24241167 DOI: 10.1177/0734242X13507313
    Proper implementation of landfill siting with the right regulations and constraints can prevent undesirable long-term effects. Different countries have respective guidelines on criteria for new landfill sites. In this article, we perform a comparative study of municipal solid waste landfill siting criteria stated in the policies and guidelines of eight different constitutional bodies from Malaysia, Australia, India, U.S.A., Europe, China and the Middle East, and the World Bank. Subsequently, a geographic information system (GIS) multi-criteria evaluation model was applied to determine new suitable landfill sites using different criterion parameters using a constraint mapping technique and weighted linear combination. Application of Macro Modeler provided in the GIS-IDRISI Andes software helps in building and executing multi-step models. In addition, the analytic hierarchy process technique was included to determine the criterion weight of the decision maker's preferences as part of the weighted linear combination procedure. The differences in spatial results of suitable sites obtained signifies that dissimilarity in guideline specifications and requirements will have an effect on the decision-making process.
    Matched MeSH terms: Geographic Information Systems
  7. Fulltext Association between Availability of Neighborhood Fast Food Outlets and Overweight Among 5⁻18 Year-Old Children in Peninsular Malaysia: A Cross-Sectional Study
    Chee Cheong K, Yoon Ling C, Kuang Hock L, Mohd Ghazali S, Chien Huey T, Che Ibrahim MK, et al.
    Int J Environ Res Public Health, 2019 02 18;16(4).
    PMID: 30781699 DOI: 10.3390/ijerph16040593
    A growing number of fast-food outlets in close proximity to residential areas raises a question as to its impact on childhood overweight and obesity. This study aimed at determining the relationship between the availability of fast-food outlets that were in close proximity to residential areas and overweight among Malaysian children aged 5 to 18 years. Measurement data on the weight and height of 5544 children (2797 boys, 2747 girls) were obtained from the National Health and Morbidity Survey 2011. Overweight (including obesity) is defined as BMI-for-age z-score > +1 SD based on the WHO growth reference. Geographic information system geospatial analysis was performed to determine the number of fast-food outlets within 1000 m radius from the children's residential address. Multiple logistic regression was conducted to examine the association between the availability of fast-food outlets (none or more than one outlet) and overweight with adjustment for age, sex, ethnicity, monthly household income, parental educational level, residential area and supermarket density. Our results showed that the prevalence of overweight was 25.0% and there was a statistically significant association between the density of fast-food outlets and overweight (odds ratio: 1.23, 95% confidence interval: 1.03, 1.47). Our study suggested that the availability of fast-food outlets with close proximity in residential areas was significantly associated with being overweight among children. Limiting the number of fast-food outlets in residential areas could have a significant effect in reducing the prevalence of overweight among Malaysian children.
    Matched MeSH terms: Geographic Information Systems
  8. Occurrence, fate and environmental risk of linear alkylbenzene sulfonate in the Langat and Selangor River basins, Malaysia
    Sakai N, Shirasaka J, Matsui Y, Ramli MR, Yoshida K, Ali Mohd M, et al.
    Chemosphere, 2017 Apr;172:234-241.
    PMID: 28081507 DOI: 10.1016/j.chemosphere.2016.12.139
    Five homologs (C10-C14) of linear alkylbenzene sulfonate (LAS) were quantitated in surface water collected in the Langat and Selangor River basins using liquid chromatography-tandem mass spectrometry (LC-MS/MS). A geographic information system (GIS) was used to spatially analyze the occurrence of LAS in both river basins, and the LAS contamination associated with the population was elucidated by spatial analysis at a sub-basin level. The LAS concentrations in the dissolved phase (<0.45 μm) and 4 fractions separated by particle size (<0.1 μm, 0.1-1 μm, 1-11 μm and >11 μm) were analyzed to elucidate the environmental fate of LAS in the study area. The environmental risks of the observed LAS concentration were assessed based on predicted no effect concentration (PNEC) normalized by a quantitative structure-activity relationship model. The LAS contamination mainly occurred from a few populated sub-basins, and it was correlated with the population density and ammonia nitrogen. The dissolved phase was less than 20% in high contamination sites (>1000 μg/L), whereas it was more than 60% in less contaminated sites (<100 μg/L). The environmental fate of LAS in the study area was primarily subject to the adsorption to suspended solids rather than biodegradation because the LAS homologs, particularly in longer alkyl chain lengths, were considerably absorbed to the large size fraction (>11 μm) that settled in a few hours. The observed LAS concentrations exceeded the normalized PNEC at 3 sites, and environmental risk areas and susceptible areas to the LAS contamination were spatially identified based on their catchment areas.
    Matched MeSH terms: Geographic Information Systems
  9. Geologic hazard risk assessment of slopeland villages in southern taiwan using remote sensing techniques
    Yang SR, Yeh YL
    Sains Malaysiana, 2015;44:1677-1683.
    Countering the dangers associated the present extreme climate not only requires continuous improvement of local disaster
    prevention engineering infrastructure but also needs an enhanced understanding of the causes of the disasters. This study
    investigates the geologic hazard risk of 53 slopeland villages in Pingtung county of southern Taiwan. First, remote sensing
    (RS) techniques were utilized to interpret environmental geology and geologic hazard zonation, including dip slope, fault,
    landslide and debris flow. GIS map overlay analysis was used to further identify the extent of the geologic hazard zonation.
    As a final step, field investigation is used to comprehend geologic, topographic conditions and the geologic hazard risk
    specific to each locality. Based on data analysis and field investigation results, this study successfully integrates RS, GIS
    and GPS techniques to construct a geologic hazard risk assessment method of slopeland village. The results of this study
    can be used to promote support for future disaster prevention and disaster mitigation efforts.
    Matched MeSH terms: Geographic Information Systems
  10. Spatial and temporal risk quotient based river assessment for water resources management
    Wan Mohtar WHM, Abdul Maulud KN, Muhammad NS, Sharil S, Yaseen ZM
    Environ Pollut, 2019 May;248:133-144.
    PMID: 30784832 DOI: 10.1016/j.envpol.2019.02.011
    Malaysia depends heavily on rivers as a source for water supply, irrigation, and sustaining the livelihood of local communities. The evolution of land use in urban areas due to rapid development and the continuous problem of illegal discharge have had a serious adverse impact on the health of the country's waterways. Klang River requires extensive rehabilitation and remediation before its water could be utilised for a variety of purposes. A reliable and rigorous remediation work plan is needed to identify the sources and locations of streams that are constantly polluted. This study attempts to investigate the feasibility of utilising a temporal and spatial risk quotient (RQ) based analysis to make an accurate assessment of the current condition of the tributaries in the Klang River catchment area. The study relies on existing data sets on Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Suspended Solids (TSS), and Ammonia (NH3) to evaluate the water quality at thirty strategic locations. Analysis of ammonia pollution is not only based on the limit established for river health but was expanded to include the feasibility of using the water for water intake, recreational activities, and sustaining fish population. The temporal health of Klang River was evaluated using the Risk Matrix Approach (RMA) based on the frequency of RQ > 1 and associated colour-coded hazard impacts. By using the developed RMA, the hazard level for each parameter at each location was assessed and individually mapped using Geographic Information System (GIS). The developed risk hazard mapping has high potential as one of the essential tools in making decisions for a cost-effective river restoration and rehabilitation.
    Matched MeSH terms: Geographic Information Systems
  11. Oil spill trajectory modelling and environmental vulnerability mapping using GNOME model and GIS
    Balogun AL, Yekeen ST, Pradhan B, Wan Yusof KB
    Environ Pollut, 2021 Jan 01;268(Pt A):115812.
    PMID: 33143984 DOI: 10.1016/j.envpol.2020.115812
    This study develops an oil spill environmental vulnerability model for predicting and mapping the oil slick trajectory pattern in Kota Tinggi, Malaysia. The impact of seasonal variations on the vulnerability of the coastal resources to oil spill was modelled by estimating the quantity of coastal resources affected across three climatic seasons (northeast monsoon, southwest monsoon and pre-monsoon). Twelve 100 m3 (10,000 splots) medium oil spill scenarios were simulated using General National Oceanic and Atmospheric Administration Operational Oil Modeling Environment (GNOME) model. The output was integrated with coastal resources, comprising biological, socio-economic and physical shoreline features. Results revealed that the speed of an oil slick (40.8 m per minute) is higher during the pre-monsoon period in a southwestern direction and lower during the northeast monsoon (36.9 m per minute). Evaporation, floating and spreading are the major weathering processes identified in this study, with approximately 70% of the slick reaching the shoreline or remaining in the water column during the first 24 h (h) of the spill. Oil spill impacts were most severe during the southwest monsoon, and physical shoreline resources are the most vulnerable to oil spill in the study area. The study concluded that variation in climatic seasons significantly influence the vulnerability of coastal resources to marine oil spill.
    Matched MeSH terms: Geographic Information Systems
  12. Soil erosion potential at sungai bilut catchment, Raub, Pahang using integration of rusle and GIS
    Tukimat Lihan, Nur Fatin Khodri, Muzzneena Ahmad Mustapha, Zulfahmi Ali Rahman, Wan Mohd Razi Idris
    Sains Malaysiana, 2018;47:2241-2249.
    Aktiviti guna tanah di kawasan lembangan adalah salah satu faktor yang mendorong kepada kemerosotan kualiti air
    sungai akibat daripada hakisan tanih. Potensi hakisan tanih di kawasan lembangan Sungai Bilut, Raub, Pahang yang
    menjadi sumber bekalan air minuman utama di daerah Raub boleh ditentukan dengan menggunakan integrasi model
    Semakan Semula Persamaan Kehilangan Tanih Universal (RUSLE) dan Sistem Maklumat Geografi (GIS). Kajian ini
    bertujuan untuk menentukan potensi hakisan tanih dan faktor utama yang mempengaruhi kadar hakisan tanih. Kajian ini
    melibatkan penggunaan data sekunder yang terdiri daripada data hujan, data siri tanih dan topografi bagi menghasilkan
    faktor kehakisan hujan (R), kebolehhakisan tanih (K), serta panjang dan kecuraman cerun (LS). Faktor litupan tumbuhan
    (C) dan amalan pemuliharaan (P) pula dijana daripada imej satelit Landsat 8 (2014). Keputusan kajian menunjukkan
    nilai faktor R di kawasan kajian ialah 8927.68-9775.18 MJ mm ha-1 jam-1 tahun-1, nilai K ialah 0.036-0.500 tan jam-1
    MJ-1 mm-1, nilai LS ialah 0-514, nilai C ialah 0.03-0.80 dan nilai P ialah 0.1-0.7. Kawasan yang mempunyai potensi
    hakisan sangat rendah hingga rendah meliputi 81%, manakala potensi hakisan tanih sederhana hingga sangat tinggi
    meliputi 19% daripada keseluruhan kawasan kajian. Model yang dihasilkan mempunyai ketepatan sebanyak 81%. Faktor
    utama yang mempengaruhi berlakunya hakisan tanih di kawasan kajian adalah faktor topografi, litupan tumbuhan dan
    kebolehhakisan tanih. Keputusan menunjukkan analisis integrasi RUSLE dan GIS berpotensi dalam penentuan potensi
    hakisan tanih untuk kawasan luas yang mempunyai pelbagai jenis guna tanah, topografi dan jenis tanih.
    Matched MeSH terms: Geographic Information Systems
  13. Fulltext Accelerometer-measured physical activity and its relationship with body mass index (BMI) and waist circumference (WC) measurements: a cross-sectional study on Malaysian adults
    Lee, Yi Yi, Narimah Samat, Wan Manan Wan Muda
    Malays J Nutr, 2017;23(3):397-408.
    MyJurnal
    Introduction: Physical activity has been shown to be beneficial for the prevention of
    obesity and non-communicable diseases. Our contemporary way of life that is technology
    dependent has significantly reduced physical activity. This study aimed to determine
    accelerometer-measured physical activity (moderate-to-vigorous physical activity (MVPA))
    among adults in high and low walkability neighbourhoods in Penang and Kota Bharu,
    Malaysia.

    Methods: Participants (n=490) were sampled using multistage sampling method
    from neighbourhoods with varied levels of walkability using Geographical Information
    System (GIS). Physical activity was measured objectively using Actigraph GT3X+
    accelerometers, worn by the participants on their waists for a period of 5 to 7 days.

    Results:
    The participants had a mean of 13.5 min/day of MVPA. Total MVPA was significantly
    higher among participants in high walkability neighbourhoods (19.7 min/day vs. 9.1 min/
    day). Results from t-test showed that the time spent on MVPA per day was significantly
    lower among participants residing in low walkability neighbourhoods. The final model
    of the MIXED model statistical tests showed that total MVPA was significantly associated
    with BMI, but not with WC measurements, after adjusting for covariates.

    Conclusion: Most
    of the participants had very low MVPA and did not achieve the current physical activity
    recommendations, implying that Malaysian adults residing in these two cities were not
    physically active to achieve health benefits. Results are suggestive of the importance of the
    walkability concept in neighbourhoods in encouraging physical activity and healthy body
    weight among Malaysians.
    Matched MeSH terms: Geographic Information Systems
  14. Environmental planning strategies for optimum solid waste landfill siting
    Sumiani Y, Onn C, Mohd Din M, Wan Jaafar W
    Sains Malaysiana, 2009;38.
    The use of environmental planning tools for optimum solid waste landfill siting taking into account all environmental implications was carried out by applying Life Cycle Analysis (LCA) to enhance the research information obtained from initial analysis using Geographical Information Systems (GIS). The objective of this study is to identify the most eco-friendly landfill site by conducting a LCA analysis upon 5 potential GIS generated sites which incorporated eleven important criteria related to the social, environmental, and economical factors. The LCA analysis utilized the daily distance covered by collection trucks among the 5 selected landfill sites to generate inventory data on total energy usage for each landfill sites. The planning and selection of the potential sites were facilitated after conducting environmental impact analysis upon the inventory data which showed the least environmental impact.
    Matched MeSH terms: Geographic Information Systems
  15. Fulltext Range Measurement and a Habitat Suitability Map for the Norway Rat in a Highly Developed Urban Environment
    Oyedele DT, Sah SA, Kairuddinand L, Wan Ibrahim WM
    Trop Life Sci Res, 2015 Dec;26(2):27-44.
    PMID: 26868708 MyJurnal
    Studies of habitat suitability (HS) are essential when animals' habitats have been altered or when animals migrate to a habitat different from their natural habitat. This study assessed HS and used an integrated geographic information system in the assessment of Rattus norvegicus in a highly developed urban environment. Using data from the Campbell market and the police quarters of George Town, Malaysia, home range (through the use of 100% Minimum Convex Polygon [MCP], 95% MCP and 95% Harmonic Mean [HM]) was estimated. Home range for male rats at Campbell market reached an asymptote, with a slight increase, at 96 radio fixes (home range = 133.52 m(2); core area = 29.39 m(2)). Female rats reached an asymptote at 62 radio fixes (home range = 13.38 m(2); core area = 9.17 m(2)). At Campbell market, male rats emerged at 1900 hours every day, whereas females emerged at 2000 hours; at police quarters, the most common time of emergence for males was 2000 hours and for females was 2200. Raster charts of R. norvegicus showed that rat hot spots can be grouped into 4 zones (market, shop houses, settlement and general places). The standardised raster chart isolated the market as the major rallying points of the rats (hot spots) by producing the highest rats frequencies of 255. All of the habitat suitability thresholds, including the built-up points, skip bins, water source and nature of the site explored in this study, produced a structural pattern (monotonic increase or decrease) of habitat suitability.
    Matched MeSH terms: Geographic Information Systems
  16. Fulltext Evaluation of the spatial growth of Bauchi metropolis using remote sensing and geographic information systems (GIS) techniques
    Mohammed Aliyu Modibbo, Mohammed Arif Shahidah, Isah Funtua Abdulkadir, Umar Wali
    Journal of Advanced Research in Applied Sciences and Engineering Technology, 2017;6(1):28-36.
    MyJurnal
    This paper has evaluated the spatial growth of Bauchi Metropolis from 1976 to 2015
    through the application of Remote Sensing and GIS techniques. Various satellite
    imageries of the metropolis (Landsat MSS of 1976, TM of 1986, 1996 and ETM+ of 2006
    and 2015) were integrated; processed and classified using ERDAS imagine 9.1. The
    results showed an increase in area from 11.68km2
    in 1976 to 12.51km2
    in 1986 to
    32.44km2 in 1996, to 49.66km2
    in 2006 and finally to 89.23km2 in 2015. It is
    recommended that government should provide the required capacities for the use of
    Remote Sensing and GIS in planning for the growth of the town.
    Matched MeSH terms: Geographic Information Systems
  17. Analysis of dental services distribution in Malaysia: a geographic information systems - based approach
    Md Bohari NF, Kruger E, John J, Tennant M
    Int Dent J, 2019 Jun;69(3):223-229.
    PMID: 30565655 DOI: 10.1111/idj.12454
    OBJECTIVE: The aim of this study was to analyse, in detail, the distribution of primary dental clinics in relation to the Malaysian population and relative population wealth, to test the hypothesis that an uneven distribution of dental services exists in Malaysia.

    METHOD: This 2016 study located every dental practice in Malaysia (private and public) and mapped these practices against population, using Geographic Information Systems (GIS) tools. Population clusters within 5, 10 and 20 km of a dental clinic were identified, and clinic-to-population ratios were ascertained. Population data were obtained from the Population and Housing Census of Malaysia 2010. Population relative wealth was obtained from the 2014 Report on Household Income and Basic Amenities Survey for Malaysia. The physical address for each dental practice in Malaysia was gathered from the Official Portal of Ministry of Health Malaysia. All data for analysis were extracted from the integrated database in Quantum GIS (QGIS) into Microsoft Excel.

    RESULT: The population of Malaysia (24.9 million) was distributed across 127 districts, with 119 (94%) having at least one dental clinic. Sixty-four districts had fewer than 10 dental clinics, and 11.3% of Malaysians did not reside in the catchment of 20 km from any dental clinic. The total dental clinic-to-population ratio was 1:9,000: for public dental clinics it was 1:38,000 and for private clinics it was 1:13,000.

    CONCLUSION: Dental services were distributed relative to high population density, were unevenly distributed across Malaysia and the majority of people with the highest inaccessibility to a dental service resided in Malaysian Borneo.

    Matched MeSH terms: Geographic Information Systems*
  18. Fulltext Left-handed metamaterial bandpass filter for GPS, Earth Exploration-Satellite and WiMAX frequency sensing applications
    Alam MJ, Ahamed E, Faruque MRI, Islam MT, Tamim AM
    PLoS One, 2019;14(11):e0224478.
    PMID: 31714917 DOI: 10.1371/journal.pone.0224478
    Interferences and accuracy problem are one of the most talked issues in today's world for sensor technology. To deal with this contention, a microstrip framework consisting of a dual mode double negative (DNG) metamaterial based bandpass filter is presented in this article. To obtain the ultimate noise reduction bandpass filter, the proposed structure has to go through a series of development process, where the characteristics of the structure are tested to the limit. This filter is built on Rogers RT-5880 substrate with a 50Ω microstrip line. To pursue the elementary mode of resonant frequency, the ground layer of the structure is kept partially filled and a gradual analysis is executed on the prospective metamaterial (resonator) unit cell. Depending on the developed unit cell, the filter is constructed and fabricated to verify the concept, concentrating on GPS (1.55GHz), Earth Exploration-Satellite (2.70GHz) and WiMAX (3.60GHz) bands of frequencies. Moreover, the structure is investigated using Nicolson-Ross-Weir (NRW) approach to justify the metamaterial characteristics, and also tested on S-parameters, current distribution, electric and magnetic fields and quality factor. Having a propitious architecture and DNG characteristics, the proposed structure is suitable for bandpass filter for GPS, Earth Exploration-Satellite and WiMAX frequency sensing applications.
    Matched MeSH terms: Geographic Information Systems*
  19. Fulltext A review on criteria and decision-making techniques in solving landfill site selection problems
    Nur Azriati Mat, Aida Mauziah Benjamin, Syariza Abdul-Rahman
    Journal of Advanced Review on Scientific Research, 2017;37(1):14-32.
    MyJurnal
    The selection of landfill, which happens to be an environmental issue, has attracted
    the attention of many researchers from the fields of waste management and
    environmental sciences worldwide. Hence, in the attempt to overcome this problem,
    some decision-making techniques, including Geographic Information Systems (GIS)
    and Multi-Criteria Decision Analysis (MCDA), have been widely utilized in prior studies,
    where multiple criteria, particularly in site selection process, have been employed.
    With that, this article identifies the selection criteria for landfill selection and presents
    a review concerning decision-making techniques that have been used in past studies
    for two important phases involved during the process of site selection, namely, (1)
    preliminary site screening, and (2) assessment of site suitability. As such, some 82
    articles chosen from 34 peer-reviewed journals had been investigated in detail. The
    results showed that 42.68% of the selected articles integrated GIS and MCDA
    techniques to solve the problem of landfill site selection, and this is followed by
    integrating GIS and fuzzy MCDA technique (18.29%). Both these techniques are indeed
    powerful tools that can guide decision-makers to solve problems in making decisions
    on the basis of various criteria under certainty and uncertainty results, mainly involving
    environmental issues.
    Matched MeSH terms: Geographic Information Systems
  20. Fulltext A Modified Hopfield Neural Network Algorithm (MHNNA) Using ALOS Image for Water Quality Mapping
    Kzar AA, Mat Jafri MZ, Mutter KN, Syahreza S
    Int J Environ Res Public Health, 2016 Jan;13(1).
    PMID: 26729148 DOI: 10.3390/ijerph13010092
    Decreasing water pollution is a big problem in coastal waters. Coastal health of ecosystems can be affected by high concentrations of suspended sediment. In this work, a Modified Hopfield Neural Network Algorithm (MHNNA) was used with remote sensing imagery to classify the total suspended solids (TSS) concentrations in the waters of coastal Langkawi Island, Malaysia. The adopted remote sensing image is the Advanced Land Observation Satellite (ALOS) image acquired on 18 January 2010. Our modification allows the Hopfield neural network to convert and classify color satellite images. The samples were collected from the study area simultaneously with the acquiring of satellite imagery. The sample locations were determined using a handheld global positioning system (GPS). The TSS concentration measurements were conducted in a lab and used for validation (real data), classification, and accuracy assessments. Mapping was achieved by using the MHNNA to classify the concentrations according to their reflectance values in band 1, band 2, and band 3. The TSS map was color-coded for visual interpretation. The efficiency of the proposed algorithm was investigated by dividing the validation data into two groups. The first group was used as source samples for supervisor classification via the MHNNA. The second group was used to test the MHNNA efficiency. After mapping, the locations of the second group in the produced classes were detected. Next, the correlation coefficient (R) and root mean square error (RMSE) were calculated between the two groups, according to their corresponding locations in the classes. The MHNNA exhibited a higher R (0.977) and lower RMSE (2.887). In addition, we test the MHNNA with noise, where it proves its accuracy with noisy images over a range of noise levels. All results have been compared with a minimum distance classifier (Min-Dis). Therefore, TSS mapping of polluted water in the coastal Langkawi Island, Malaysia can be performed using the adopted MHNNA with remote sensing techniques (as based on ALOS images).
    Matched MeSH terms: Geographic Information Systems
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