62 research outputs found

    Route Optimization of MSW Collection and Transport Using a GIS-Based Analysis on the Tourism Island

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    The Municipal Solid Waste (MSW) management on Si Chang Island is challenging in terms of its limited land resources, high cost of waste treatment, and seasonal fluctuations in waste volumes from tourists and shipping activities. There are sufficient waste bins available to cover MSW production on the island. The downside of the management is an inappropriate open dumping site that is prone to environmental pollution and health risk. However, resilience is shown in the implementation of an integrated approach of waste separation, composting, and incineration. This study developed a complete road network and applied a network analyst extension, which was useful in the area of optimization of MSW collection and transport. Two optimal routes were shown for MSW collection. Two vehicles were utilized to collect about 10 tons of MSW per day in two trips. A total travel distance for one-day transportation was 38.5 km. Carbon dioxide (CO2) emission from vehicles during MSW collection and transport was 0.85 g/km, accounting for 119 t CO2/yr

    Land Use Change Monitoring and Modelling using GIS and Remote Sensing Data for Watershed Scale in Thailand

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    Landsat 7 Enhanced Thematic Mapper (ETM), Landsat 8 Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS) images obtained in 1991, 2005 and 2014 with maps, and field survey data were used to classify land use and land cover (LULC) changes over 23 years and predict soil erosion risk locations in the Khlong Kui watershed (73,700 ha), Prachuap Khiri Khan province, Thailand. Classified images together with soil features, slope and rainfall data were used to identify potential risk areas of soil erosion. Based on field check data, the overall classification accuracy was accessed from random samples that resulted as 80% for 1991, 83% for 2005 and 86% for 2014. The study discovered that rice field and rangeland increased by 1.12 and 2.81%, respectively, deciduous forest, and on the other hand, it decreased by 8.28%. GIS analysis identified the potential risk areas of soil erosion as 46,431 ha (0.63%) at very high risk

    Exploring spatial patterns and hotspots of diarrhea in Chiang Mai, Thailand

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    <p>Abstract</p> <p>Background</p> <p>Diarrhea is a major public health problem in Thailand. The Ministry of Public Health, Thailand, has been trying to monitor and control this disease for many years. The methodology and the results from this study could be useful for public health officers to develop a system to monitor and prevent diarrhea outbreaks.</p> <p>Methods</p> <p>The objective of this study was to analyse the epidemic outbreak patterns of diarrhea in Chiang Mai province, Northern Thailand, in terms of their geographical distributions and hotspot identification. The data of patients with diarrhea at village level and the 2001–2006 population censuses were collected to achieve the objective. Spatial analysis, using geographic information systems (GIS) and other methods, was used to uncover the hidden phenomena from the data. In the data analysis section, spatial statistics such as quadrant analysis (QA), nearest neighbour analysis (NNA), and spatial autocorrelation analysis (SAA), were used to identify the spatial patterns of diarrhea in Chiang Mai province. In addition, local indicators of spatial association (LISA) and kernel density (KD) estimation were used to detect diarrhea hotspots using data at village level.</p> <p>Results</p> <p>The hotspot maps produced by the LISA and KD techniques showed spatial trend patterns of diarrhea diffusion. Villages in the middle and northern regions revealed higher incidences. Also, the spatial patterns of diarrhea during the years 2001 and 2006 were found to represent spatially clustered patterns, both at global and local scales.</p> <p>Conclusion</p> <p>Spatial analysis methods in GIS revealed the spatial patterns and hotspots of diarrhea in Chiang Mai province from the year 2001 to 2006. To implement specific and geographically appropriate public health risk-reduction programs, the use of such spatial analysis tools may become an integral component in the epidemiologic description, analysis, and risk assessment of diarrhea.</p

    Web access monitoring mechanism via Android WebView for threat analysis

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    Many Android apps employ WebView, a component that enables the display of web content in the apps without redirecting users to web browser apps. However, WebView might also be used for cyberattacks. Moreover, to the best of our knowledge, although some countermeasures based on access control have been reported for attacks exploiting WebView, no mechanism for monitoring web access via WebView has been proposed and no analysis results focusing on web access via WebView are available. In consideration of this limitation, we propose a web access monitoring mechanism for Android WebView to analyze web access via WebView and clarify attacks exploiting WebView. In this paper, we present the design and implementation of this mechanism by modifying Chromium WebView without any modifications to the Android framework or Linux kernel. The evaluation results of the performance achieved on introducing the proposed mechanism are also presented here. Moreover, the result of threat analysis of displaying a fake virus alert while browsing websites on Android is discussed to demonstrate the effectiveness of the proposed mechanism

    Spatially-explicit and spectral soil carbon modeling in Florida.

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    Profound shifts have occurred over the last three centuries in which human actions have become the main driver to global environmental change. In this new epoch, the Anthropocene, human-driven changes such as population growth, climate and land use change, are pushing the Earth system well outside its normal operating range causing severe and abrupt environmental change. In this context, we present research highlights from Florida (150,000 km2) showing how anthropogenic-induced changes have had major impacts on carbon dynamics in soils, including (i) modeling of carbon and nutrient dynamics and soil carbon sequestration impacted by climate and land use change; (ii) geospatial assessment of soil carbon stocks and pools, and (iii) spectral-based soil carbon modeling. Our research is embedded in the STEP-AWBH modeling concept which explicitly incorporates Human forcings and time-dependent evolution of Atmospheric, Water, and Biotic factors into the modeling process. Spatially-explicit soil carbon observations were fused with ancillary environmental data and various statistical and geostatistical methods were used to upscale soil carbon across the region. Our results suggest that soil hydrologic and taxonomic, biotic (vegetation and land use), and climatic properties show complex interactions explaining the variation of soil carbon within this heterogeneous subtropical landscape

    The Terrestrial Carbon (Terra C) Information System to facilitate carbon synthesis across heterogeneous landscapes.

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    There are urgent needs to better synthesize knowledge and data across large regions and time periods to address global climate change, conduct soil/terrestrial carbon accounting, model carbon dynamics, assess carbon sequestration, and develop strategies for mitigation and adaptation. To address these needs we developed the Terrestrial Carbon (TerraC) Information System dedicated to advance soil/terrestrial carbon science. TerraC offers user-friendly tools to upload, store, manage, query, analyze, and download lab and field data characterizing carbon in soils, plants/biomass, atmosphere, water, and whole ecosystems. The purpose of TerraC is three-fold to: (i) advance carbon science through sharing of carbon and ancillary environmental data; (ii) facilitate environmental synthesis; and (iii) enhance collaboration among students, faculty, scientists, and extension specialists through shared resources. Data and metadata stored in TerraC can be shared privately among selected users (groups) or publicly with any user. We integrated various spatially-explicit soil carbon and ancillary environmental data collected in Florida representing different time periods, and conducted a synthesis analysis on soil carbon that will be presented as a case study. Detailed information about TerraC and data sharing options are available at: http://TerraC.ifas.ufl.edu

    Spatio-Temporal Diffusion Pattern and Hotspot Detection of Dengue in Chachoengsao Province, Thailand

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    In recent years, dengue has become a major international public health concern. In Thailand it is also an important concern as several dengue outbreaks were reported in last decade. This paper presents a GIS approach to analyze the spatial and temporal dynamics of dengue epidemics. The major objective of this study was to examine spatial diffusion patterns and hotspot identification for reported dengue cases. Geospatial diffusion pattern of the 2007 dengue outbreak was investigated. Map of daily cases was generated for the 153 days of the outbreak. Epidemiological data from Chachoengsao province, Thailand (reported dengue cases for the years 1999–2007) was used for this study. To analyze the dynamic space-time pattern of dengue outbreaks, all cases were positioned in space at a village level. After a general statistical analysis (by gender and age group), data was subsequently analyzed for temporal patterns and correlation with climatic data (especially rainfall), spatial patterns and cluster analysis, and spatio-temporal patterns of hotspots during epidemics. The results revealed spatial diffusion patterns during the years 1999–2007 representing spatially clustered patterns with significant differences by village. Villages on the urban fringe reported higher incidences. The space and time of the cases showed outbreak movement and spread patterns that could be related to entomologic and epidemiologic factors. The hotspots showed the spatial trend of dengue diffusion. This study presents useful information related to the dengue outbreak patterns in space and time and may help public health departments to plan strategies to control the spread of disease. The methodology is general for space-time analysis and can be applied for other infectious diseases as well

    Typhoid Fever and Its Association with Environmental Factors in the Dhaka Metropolitan Area of Bangladesh: A Spatial and Time-Series Approach

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    Typhoid fever is a major cause of death worldwide with a major part of the disease burden in developing regions such as the Indian sub-continent. Bangladesh is part of this highly endemic region, yet little is known about the spatial and temporal distribution of the disease at a regional scale. This research used a Geographic Information System to explore, spatially and temporally, the prevalence of typhoid in Dhaka Metropolitan Area (DMA) of Bangladesh over the period 2005-9. This paper provides the first study of the spatio-temporal epidemiology of typhoid for this region. The aims of the study were: (i) to analyse the epidemiology of cases from 2005 to 2009; (ii) to identify spatial patterns of infection based on two spatial hypotheses; and (iii) to determine the hydro-climatological factors associated with typhoid prevalence. Case occurrences data were collected from 11 major hospitals in DMA, geocoded to census tract level, and used in a spatio-temporal analysis with a range of demographic, environmental and meteorological variables. Analyses revealed distinct seasonality as well as age and gender differences, with males and very young children being disproportionately infected. The male-female ratio of typhoid cases was found to be 1.36, and the median age of the cases was 14 years. Typhoid incidence was higher in male population than female (χ2 = 5.88, p0.05). A statistically significant inverse association was found between typhoid incidence and distance to major waterbodies. Spatial pattern analysis showed that there was a significant clustering of typhoid distribution in the study area. Moran\u27s I was highest (0.879; p<0.01) in 2008 and lowest (0.075; p<0.05) in 2009. Incidence rates were found to form three large, multi-centred, spatial clusters with no significant difference between urban and rural rates. Temporally, typhoid incidence was seen to increase with temperature, rainfall and river level at time lags ranging from three to five weeks. For example, for a 0.1 metre rise in river levels, the number of typhoid cases increased by 4.6% (95% CI: 2.4-2.8) above the threshold of 4.0 metres (95% CI: 2.4-4.3). On the other hand, with a 1°C rise in temperature, the number of typhoid cases could increase by 14.2% (95% CI: 4.4-25.0)

    คอนกรีตบล็อกจากแอสฟัลต์คอนกรีตเก่าConcrete Block from Recycled Asphalt Concrete

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    งานวิจัยนี้มีวัตถุประสงค์เพื่อศึกษาการใช้หินแอสฟัลต์คอนกรีตเก่า เป็นมวลรวมในผลิตภัณฑ์คอนกรีตบล็อกโดยสัดส่วนผสมคอนกรีตที่ใช้ในการทดสอบคือ 1 : 6 : 0.4 หมายถึง ปูนซีเมนต์ 1 ต่อมวลรวม 6 ต่อน้ำ 0.40 ส่วนโดยน้ำหนัก เปรียบเทียบคุณสมบัติของคอนกรีตบล็อกที่ใช้หินแอสฟัลต์คอนกรีตเก่า และหินฝุ่นจากเหมืองหินปูน (มวลรวมทั่วไป) ขึ้นรูปคอนกรีตบล็อกมาตรฐาน ขนาด 7×19×39 เซนติเมตร ด้วยเครื่องอัดคอนกรีตบล็อก ทดสอบตามมาตรฐาน มอก. 58-2530 เรื่องคอนกรีตบล็อกชนิดไม่รับน้ำหนักผลการทดสอบ พบว่าคอนกรีตบล็อกที่ใช้หินแอสฟัลต์คอนกรีตเก่าเป็นมวลรวม มีความต้านทานแรงอัดและการดูดซึมน้ำต่ำกว่าคอนกรีตบล็อกปกติ อย่างไรก็ตามคอนกรีตบล็อกทั้งหมดมีสมบัติผ่านตามที่มาตรฐาน มอก.กำหนด ทำให้คอนกรีตบล็อกจากแอสฟัลต์คอนกรีตเก่าสามารถใช้เป็นวัสดุสำหรับก่อผนังได้ดีThis research aims to examine the use of stone dust from recycled asphalt concrete aggregate in concrete block products. The mixture ratio of portland cement type1: stone dust or recycled asphalt concrete aggregate: water is 1: 6 : 0.4 by weight. Types of stone dust from recycled asphalt concrete aggregate and limestone mine (general aggregate) are compared in concrete block properties. The concrete block samples are cast in 7×19×39 cubic centimeter of dimension with a concrete block molding machine. The concrete block sample testing follows the TIS 58-2530 on non-load bearing concrete blocks. As results, the compressive strength and water absorption of recycled asphalt concrete are lower than general concrete blocks. All samples can classify as the standard so it can be used as material for a wall. All samples have passed the TIS standard. Thus, concrete blocks from recycled asphalt concrete can be used for wall construction purposes

    An investigation of social and emotional skills and their relationship with behaviour problems in Thai secondary students

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    Research Doctorate - Doctor of PhilosophyThere were two major aims in the current study. The first was to investigate the psychometric properties of the Thai Social and Emotional Skill Rating Scale (TSESRS) developed by the author. The measurement model of this material is a three factor model containing social skills, emotional skills, and social-cognitive skills. These factors were measured from eight indicators. Data were collected from 685 lower secondary school students who were studying in schools under the jurisdiction of the Phatthalung Educational Area Office, Thailand. Materials used in this phase were the trial version of the TSESRS, the Thai Emotional Skill Scale (TESS) and the Thai Social Skill Scale (TSSS). The evidence suggested that the following psychometric properties of the TSESRS are within the acceptable cut-off levels: item-validity, item-reliability, item-discrimination, test-reliability, construct validity, criterion related validity, and factorial validity. It was also found that a three factor model was the best fitting model. These results suggest that the TSESRS measures three distinct latent constructs, that is, social skills, emotional skills, and social-cognitive skills. The second aim was to examine the structural relationship of three exogenous variables, that is, social skills, emotional skills, and social-cognitive skills with two types of behaviour problems, that is, internalizing and externalizing problems. Data for this phase were collected from 951 students drawn from the same population as the first phase. Materials used for data collection were the TSESRS and the Thai version of the Youth Self-Report (YSR). The results revealed that among the three exogenous variables, social-cognitive skills was the only significant predictor of both internalizing and externalizing problems. The relationship between social-cognitive skills and two types of behaviour problems was negative. This means that the higher a students’ social-cognitive skills, the lower their level of internalizing and externalizing problems. The indicators of social cognitive skills were emotion control, problem solving, and decision making skills. This finding has important implications for dealing with behaviour problems in Thai students. Thai teachers or educators may use these findings for selecting from available programs or for developing new programs
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