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Characteristics of hepatocellular carcinoma in cirrhotic and non-cirrhotic non-alcoholic fatty liver disease 被引量:24
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作者 Christopher Leung Sern Wei Yeoh +4 位作者 Desmond Patrick Shara Ket Kaye Marion Paul Gow Peter W Angus 《World Journal of Gastroenterology》 SCIE CAS 2015年第4期1189-1196,共8页
AIM: To determine characteristics and prognosticpredictors of patients with hepatocellular carcinoma(HCC) in association with non-alcoholic fatty liver disease(NAFLD).METHODS: We reviewed the records of all patients w... AIM: To determine characteristics and prognosticpredictors of patients with hepatocellular carcinoma(HCC) in association with non-alcoholic fatty liver disease(NAFLD).METHODS: We reviewed the records of all patients with NAFLD associated HCC between 2000 and 2012. Data collected included demographics; histology; presence or absence of cirrhosis, size and number of HCC, alpha-fetoprotein, body mass index(BMI), and the presence of diabetes, hypertension, or dyslipidaemia.RESULTS: Fifty-four patients with NAFLD associated HCC were identified. Mean age was 64 years with 87% male. Fifteen percent(8/54) were not cirrhotic. 11%, 24% and 50% had a BMI of < 25 kg/m2, 25-29 kg/m2 and ≥ 30 kg/m2 respectively. Fifty-nine percent were diabetic, 44% hypertensive and 26% hyperlipidaemic. Thirty-four percent of the patients had ≤ 1 of these risk factors. Non-cirrhotics had a significantly larger mean tumour diameter at diagnosis than cirrhotics(P = 0.041). Multivariate analysis did not identify any other patient characteristics that predicted the size or number of HCC.CONCLUSION: HCC can develop in NAFLD without cirrhosis. At diagnosis such tumours are larger than those in cirrhotics, conferring a poorer prognosis. 展开更多
关键词 HEPATOCELLULAR CARCINOMA Non-alcoholic FATTY liver
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A Method for Rapidly Determining the Optimal Distribution Locations of GNSS Stations for Orbit and ERP Measurement Based on Map Grid Zooming and Genetic Algorithm 被引量:3
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作者 Qianxin Wang Chao Hu Ya Mao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2018年第12期509-525,共17页
Designing the optimal distribution of Global Navigation Satellite System(GNSS)ground stations is crucial for determining the satellite orbit,satellite clock and Earth Rotation Parameters(ERP)at a desired precision usi... Designing the optimal distribution of Global Navigation Satellite System(GNSS)ground stations is crucial for determining the satellite orbit,satellite clock and Earth Rotation Parameters(ERP)at a desired precision using a limited number of stations.In this work,a new criterion for the optimal GNSS station distribution for orbit and ERP determination is proposed,named the minimum Orbit and ERP Dilution of Precision Factor(OEDOP)criterion.To quickly identify the specific station locations for the optimal station distribution on a map,a method for the rapid determination of the selected station locations is developed,which is based on the map grid zooming and heuristic technique.Using the minimum OEDOP criterion and the proposed method for the rapid determination of optimal station locations,an optimal or near-optimal station distribution scheme for 17 newly built BeiDou Navigation Satellite System(BDS)global tracking stations is suggested.To verify the proposed criterion and method,real GNSS data are processed.The results show that the minimum OEDOP criterion is valid,as the smaller the value of OEDOP,the better the precision of the satellite orbit and ERP determination.Relative to the exhaustive method,the proposed method significantly improves the computational efficiency of the optimal station location determination.In the case of 3 newly built stations,the computational efficiency of the proposed method is 35 times greater than that of the exhaustive method.As the number of stations increases,the improvement in the computational efficiency becomes increasingly obvious. 展开更多
关键词 Global Navigation Satellite System(GNSS) optimal distribution of station network MAP GRID ZOOMING genetic algorithm.
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Solving single-frequency phase ambiguity using parameter weights fitting and constrained equation ambiguity resolution methods 被引量:5
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作者 阳仁贵 欧吉坤 +3 位作者 袁运斌 张克非 闻德保 Ron Grenfell 《Journal of Central South University of Technology》 EI 2006年第1期93-98,共6页
Based on the structural characteristics of the double-differenced normal equation, a new method was proposed to resolve the ambiguity float solution through a selection of parameter weights to construct an appropriate... Based on the structural characteristics of the double-differenced normal equation, a new method was proposed to resolve the ambiguity float solution through a selection of parameter weights to construct an appropriate regularized matrix, and a singular decomposition method was used to generate regularization parameters. Numerical test results suggest that the regularized ambiguity float solution is more stable and reliable than the least-squares float solution. The mean square error matrix of the new method possesses a lower correlation than the variancecovariance matrix of the least-squares estimation. The size of the ambiguity search space is reduced and the search efficiency is improved. The success rate of the integer ambiguity searching process is improved significantly when the ambiguity resolution by using constraint equation method is used to determine the correct ambiguity integervector. The ambiguity resolution by using constraint equation method requires an initial input of the ambiguity float solution candidates which are obtained from the LAMBDA method in the new method. In addition, the observation time required to fix reliable integer ambiguities can he significantly reduced. 展开更多
关键词 global position system ill-conditioned state parameter weight fitting method constraint equation integer ambiguity
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A Framework of Environmental Modelling and Information Sharing for Urban Air Pollution Control and Management 被引量:4
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作者 LIU Gang-jun FU Er-jiang +3 位作者 WANG Yun-jia ZHANG Ke-fei HAN Bao-ping ARROWSMITH Colin 《Journal of China University of Mining and Technology》 EI 2007年第2期172-178,共7页
More effective environmental pollution control and management are needed due to the increasing environ-mental impacts from a range of human activities and the growing public demands for a better living environment. Ur... More effective environmental pollution control and management are needed due to the increasing environ-mental impacts from a range of human activities and the growing public demands for a better living environment. Urban air pollution is a serious environmental issue that poses adverse impacts on the health of people and the environment in most metropolitan areas. In this paper,we propose a geoinformatics augmented framework of environmental modelling and information sharing for supporting effective urban air pollution control and management. This framework is out-lined in terms of its key components and processes including: 1) an integrated,adaptive network of sensors for envi-ronmental monitoring; 2) a set of distributed,interoperable databases for data management; 3) a set of intelligent,robust algorithms and models for environmental modelling; 4) a set of flexible,efficient user interfaces for data access and in-formation sharing; and 5) a reliable,high capacity,high performance computing and communication infrastructure for integrating and supporting other framework components and processes. 展开更多
关键词 environmental modelling information sharing urban air pollution GEOINFORMATICS
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Tropical forest canopies and their relationships with climate and disturbance: results from a global dataset of consistent field-based measurements 被引量:1
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作者 marion pfeifer alemu gonsamo +26 位作者 william woodgate luis cayuela andrew r.marshall alicia ledo timothy c.e.paine rob marchant andrew burt kim calders colin courtney-mustaphi aida cuni-sanchez nicolas j.deere dereje denu jose gonzalez de tanago robin hayward alvaro lau manuel j.macía pieter i.olivier petri pellikka hamidu seki deo shirima rebecca trevithick beatrice wedeux charlotte wheeler pantaleo k.t.munishi thomas martin abdul mustari philip j.platts 《Forest Ecosystems》 SCIE CSCD 2018年第1期77-90,共14页
Background: Canopy structure, defined by leaf area index (LAI), fractional vegetation cover (FCover) and fraction of absorbed photosynthetically active radiation (fAPAR), regulates a wide range of forest functi... Background: Canopy structure, defined by leaf area index (LAI), fractional vegetation cover (FCover) and fraction of absorbed photosynthetically active radiation (fAPAR), regulates a wide range of forest functions and ecosystem services. Spatially consistent field-measurements of canopy structure are however lacking, particularly for the tropics. Methods: Here, we introduce the Global LAI database: a global dataset of field-based canopy structure measurements spanning tropical forests in four continents (Africa, Asia, Australia and the Americas). We use these measurements to test for climate dependencies within and across continents, and to test for the potential of anthropogenic disturbance and forest protection to modulate those dependences. Results: Using data collected from 887 tropical forest plots, we show that maximum water deficit, defined across the most arid months of the year, is an important predictor of canopy structure, with all three canopy attributes declining significantly with increasing water deficit. Canopy attributes also increase with minimum temperature, and with the protection of forests according to both active (within protected areas) and passive measures (through topography). Once protection and continent effects are accounted for, other anthropogenic measures (e.g. human population) do not improve the model. Conclusions: We conclude that canopy structure in the tropics is primarily a consequence of forest adaptation to the maximum water deficits historically experienced within a given region. Climate change, and in particular changes in drought regimes may thus affect forest structure and function, but forest protection may offer some resilience against this effect. 展开更多
关键词 Leaf area index Fractional vegetation cover Fraction of absorbed photosynthetically active radiation Human population pressure Protected areas DROUGHT Climate change
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Effect of Climate Change on Water Resources and Water Management Practices: A Review of Research Methods and Findings with Special Reference to Australia
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作者 Gabriel Makuei Deng Makuei 《Journal of Earth Science and Engineering》 2016年第4期208-225,共18页
In this secondary research, published works on effect of climate change on water resources in other countries and in Australia were reviewed critically. Research question, objectives and assumptions were made to facil... In this secondary research, published works on effect of climate change on water resources in other countries and in Australia were reviewed critically. Research question, objectives and assumptions were made to facilitate this study. First, methods used for such studies and their results at global level were reviewed. Then Australian specific methods of study and findings were reviewed. More commonly, both globally and in Australia, simulations using long-term real data on selected climatic scenarios of global climatic models are projected for long-term future trends. The validity and certainty of predicted occurrences depend upon the closeness of real time data with scenarios to which they are projected. Even with these limitations, projections of already rising temperatures and declining rainfall on surface water and ground water availabilities show gradual decline in water availability leading to water stress both for human communities and ecosystems The role of human-induced emissions in hastening the degradation process has also been investigated. Conserving all available water, practising efficient water consumption and prudent water policies only can provide some relief from what is inevitable. 展开更多
关键词 Climate change water resources FINDINGS methods water management review
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Extreme Weather and Climate Events and Their Impacts on Island Countries in the Western Pacific: Cyclones, Floods and Droughts
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作者 Yuriy Kuleshov Simon McGree +6 位作者 David Jones Andrew Charles Andrew Cottrill Bipen Prakash Terry Atalifo Salesa Nihmei Fata Lagomauitumua Sunny K. Seuseu 《Atmospheric and Climate Sciences》 2014年第5期803-818,共16页
Increases in the frequency of extreme weather and climate events and the severity of their impacts on the natural environment and society have been observed across the globe in recent decades. In addition to natural c... Increases in the frequency of extreme weather and climate events and the severity of their impacts on the natural environment and society have been observed across the globe in recent decades. In addition to natural climate variability and greenhouse-induced climate change, extreme weather and climate events produce the most pronounced impacts. In this paper, the climate of three island countries in the Western Pacific: Fiji, Samoa and Tuvalu, has been analysed. Warming trends in annual average maximum and minimum temperatures since the 1950s have been identified, in line with the global warming trend. We present recent examples of extreme weather and climate events and their impacts on the island countries in the Western Pacific: the 2011 drought in Tuvalu, the 2012 floods in Fiji and a tropical cyclone, Evan, which devastated Samoa and Fiji in December 2012. We also relate occurrences of the extreme weather and climate events to phases of the El Ni&ntilde;o-Southern Oscillation (ENSO) phenomenon. The impacts of such natural disasters on the countries are severe and the costs of damage are astronomical. In some cases, climate extremes affect countries to such an extent that governments declare a national state of emergency, as occurred in Tuvalu in 2011 due to the severe drought’s impact on water resources. The projected increase in the frequency of weather and climate extremes is one of the expected consequences of the observed increase in anthropogenic greenhouse gas concentration and will likely have even stronger negative impacts on the natural environment and society in the future. This should be taken into consideration by authorities of Pacific Island Countries and aid donors when developing strategies to adapt to the increasing risk of climate extremes. Here we demonstrate that the modern science of seasonal climate prediction is well developed, with current dynamical climate models being able to provide skilful predictions of regional rainfall two-three months in advance. The dynamic climate model-based forecast products are now disseminated to the National Meteorological Services of 15 island countries in the Western Pacific through a range of web-based information tools. We conclude with confidence that seasonal climate prediction is an effective solution at the regional level to provide governments and local communities of island nations in the Western Pacific with valuable assistance for informed decision making for adaptation to climate variability and change. 展开更多
关键词 EXTREME Weather and Climate EVENTS Western PACIFIC CYCLONES Floods DROUGHTS
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Interdependence of Software and Progress of Mathematics in OR: Some Illustrative Cases and Challenges
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作者 Santosh Kumar Elias Munapo 《American Journal of Operations Research》 2021年第2期110-119,共10页
This paper points out that delayed or no supply of software can kill potential benefits associated with new mathematical ideas that have led to development of new mathematics in OR. It also points out that it is a sel... This paper points out that delayed or no supply of software can kill potential benefits associated with new mathematical ideas that have led to development of new mathematics in OR. It also points out that it is a self-created situation by the scientific community. This situation needs attention and should be resolved urgently. Many illustrative examples have been given to justify the claim</span></span><span>. 展开更多
关键词 Linear and Integer Programs Software Development Protean Systems Analysis of Protean Systems
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Developing a Spatial Tool for Assessing Coastal Community and Identifying Infrastructure at Risk
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作者 Sultana Nasrin Baby Colin Arrowsmith +3 位作者 Gang-Jun Liu David Mitchell Nadhir Al-Ansari Nahala Abbas 《Engineering(科研)》 2021年第1期45-55,共11页
A recent trend of sea level shows constant rising. Sea level rise has caused a significant risk to seaside areas. This study examines the potential effect of climate change and rising sea levels on coastal regions and... A recent trend of sea level shows constant rising. Sea level rise has caused a significant risk to seaside areas. This study examines the potential effect of climate change and rising sea levels on coastal regions and evaluates the susceptibility of coastal areas in Inverloch, Melbourne Australia. A model of Hypothetically Flooded Zones, based on LiDAR data was built, processed and manipulated in ArcGIS. Through applying this model, the effect of rising sea level on the infrastructures such as buildings, dwellings, roads, land use and the population was assessed. Elevation data sets of varying resolution and accuracy have been processed to show the improved quality of LiDAR data contributes to a more precise delineation of flood-prone coastal lands. After the susceptible areas to sea level rise were delineated, the worst-case scenario was calculated (based on the increase in sea level projected for 2100) and it would impacts about 0.86% of roads, 221 of different building infrastructures. This method can be used in other areas to protect the coasts due to rapid changes caused by climate change. 展开更多
关键词 Sea Level Rise LIDAR Climate Change Susceptible Area
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GPS变形监测的位移显著性检验方法研究 被引量:5
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作者 陈刚 胡友健 +2 位作者 赵斌 Kefei Zhang 梁新美 《测绘科学》 CSCD 北大核心 2008年第2期90-92,共3页
目前普遍采用的位移显著性检验方法,是人为地将客观上的空间位移问题转化为地方(局部)坐标系中的1维或2维位移问题来进行检验,既使位移检验在理论上的严密性受到损害,又使GPS能够在协议地球坐标系(ITRF或WGS-84)中同时精确测定空间3维... 目前普遍采用的位移显著性检验方法,是人为地将客观上的空间位移问题转化为地方(局部)坐标系中的1维或2维位移问题来进行检验,既使位移检验在理论上的严密性受到损害,又使GPS能够在协议地球坐标系(ITRF或WGS-84)中同时精确测定空间3维位移的优越性得不到充分利用。由于在位移转换过程中会引入误差,可能导致位移显著性检验结果不可靠,尤其是当位移量小而坐标转换误差大时可靠性更低。为了避免由于位移转换存在误差而影响位移显著性检验结果的可靠性,本文提出了用GPS进行变形监测时,直接在ITRF或WGS-84空间坐标参考框架下进行位移显著性检验的新方法—"变形误差椭球检验法",严密地推导了有关理论公式,给出了具体的检验方法,并进行了实例计算和分析。 展开更多
关键词 GPS 变形监测 位移显著性检验 变形误差椭球
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电离层残差对掩星反演温度精度的影响 被引量:6
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作者 柳聪亮 Gottfried Kirchengast +3 位作者 Kefei Zhang 谭志祥 Johannes Fritzer 孙越强 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2014年第8期2404-2414,共11页
本文以MSIS90大气模式和3D NeUoG电离层模式为大气背景,用三维射线追踪法模拟研究了太阳活动强度、地方时、掩星平面方位角对弯曲角电离层残差和温度电离层残差的影响,以及电离层残差对全球日平均温度的影响.结果表明:电离层残差是平... 本文以MSIS90大气模式和3D NeUoG电离层模式为大气背景,用三维射线追踪法模拟研究了太阳活动强度、地方时、掩星平面方位角对弯曲角电离层残差和温度电离层残差的影响,以及电离层残差对全球日平均温度的影响.结果表明:电离层残差是平流层顶部(35-50 km)和中间层底部(50-70 km)掩星大气温度反演的主要误差.在太阳活动活跃期,电离层残差对单一掩星事件的平流层顶部平均温度的影响可达1.8 K,中间层底部平均温度的影响可达7 K;对全球日平均温度的影响在平流层顶可达-0.6 K,在70 km高度处可达1.2 K.发展新的电离层改正方法或电离层残差修正算法对提高掩星大气反演精度和全球气候监测意义重大. 展开更多
关键词 掩星 温度 电离层残差 射线追踪
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Comparison of COSMIC Radio Occultation Refractivity Profiles with Radiosonde Measurements 被引量:4
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作者 徐晓华 罗佳 施闯 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2009年第6期1137-1145,共9页
In recent years, radio occultation (RO) technology making use of global positioning system (GPS) signals has been exploited to obtain profiles of atmospheric parameters in the neutral atmosphere. In this paper, th... In recent years, radio occultation (RO) technology making use of global positioning system (GPS) signals has been exploited to obtain profiles of atmospheric parameters in the neutral atmosphere. In this paper, the RO refractivity profiles obtained from the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) mission are statistically compared with the observations of 38 radiosonde stations provided by the Australian Bureau of Meteorology during the period from 15 July 2006 through 15 July 2007. Different collocation criteria are compared at first, and COSMIC RO soundings that occur within 3 hours and 300 km of radiosonde measurements are used for the final statistical comparison. The overall results show that the agreements between the COSMIC refractivity profiles and the radiosonde soundings from the 38 stations are very good at 0-30 km altitude, with mean absolute relative refractivity deviations of less than 0.5%. Latitudinal comparisons indicate that there are negative refractivity deviations in the lower troposphere over the low latitude and middle latitude regions and large standard deviations exist in the lower troposphere of low latitude regions, which can reach up to ~6%. The comparisons of COSMIC RO refractivity profiles and radiosonde observations for 3 polar stations in four different seasons indicate that the accuracy of GPS RO profiles is better in the Austral summer and autumn than in the Austral spring and winter during the year from September 2006 to August 2007. 展开更多
关键词 GPS radio occultation radiosonde soundings refractivity profiles statistical comparison
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Frequency Domain Filtering SAR Interferometric Phase Noise Using the Amended Matrix Pencil Model 被引量:1
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作者 Yandong Gao Shubi Zhang +1 位作者 Kefei Zhang Shijin Li 《Computer Modeling in Engineering & Sciences》 SCIE EI 2019年第5期349-363,共15页
Interferometric phase filtering is one of the key steps in interferometricsynthetic aperture radar (InSAR/SAR). However, the ideal filtering results are difficult toobtain due to dense fringe and low coherence regions... Interferometric phase filtering is one of the key steps in interferometricsynthetic aperture radar (InSAR/SAR). However, the ideal filtering results are difficult toobtain due to dense fringe and low coherence regions. Moreover, the InSAR/SAR datarange is relatively large, so the efficiency of interferential phase filtering is one of themajor problems. In this letter, we proposed an interferometric phase filtering methodbased on an amended matrix pencil and linear window mean filter. The combination ofthe matrix pencil and the linear mean filter are introduced to the interferometric phasefiltering for the first time. First, the interferometric signal is analyzed, and theinterferometric phase filtering is transformed into a local frequency estimation problem.Then, the local frequency is estimated using an amended matrix pencil at a window. Thelocal frequency can represent terrain changes, thus suggesting that the frequency can beaccurately estimated even in dense fringe regions. Finally, the local frequency is filteredby using a linear window mean filter, and the filtered phase is recovered. The proposedmethod is calculated by some matrices. Therefore, the computational complexity isreduced, and the efficiency of the interferometric phase filtering is improved.Experiments are conducted with simulated and real InSAR data. The proposed methodexhibits a better filtering effect and an ideal efficiency as compared with the traditionalfiltering method. 展开更多
关键词 INTERFEROMETRIC phase filtering INTERFEROMETRIC SYNTHETIC APERTURE radar local frequency estimation amended matrix PENCIL linear WINDOW mean filter
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Estimation of the Volume of Coarse Woody Debris in Eucalyptus Forest using LiDAR Derived Forest Structure Variables 被引量:1
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作者 Naoko Miura Susumu Goto Simon Jones 《Journal of Environmental Science and Engineering(B)》 2013年第8期501-506,共6页
CWD (coarse woody debris) plays an important role in nutrient cycling, habitat for species and more recently carbon accounting in forest ecosystems. LiDAR (light detection and ranging) technology has demonstrated ... CWD (coarse woody debris) plays an important role in nutrient cycling, habitat for species and more recently carbon accounting in forest ecosystems. LiDAR (light detection and ranging) technology has demonstrated utility in capturing forest structure information. This paper proposes an indirect method of assessing downed CWD using LiDAR derived forest structure variables. Fieldwork was conducted to measure CWD volume in an Eucalyptus forest in Tasmania. A GLM (generalized linear model) to statistically estimate CWD volume in the Eucalyptus forest was developed using a LiDAR derived FCS (forest characterisation scheme): the openings above the ground, low and medium vegetation, canopy cover, presence of understorey and mid-storey vegetation and high trees, and the vertical canopy density of high trees. Five structural variables were selected for the best model based on AIC (Akaike's Information Criterion) by stepwise selection. The applicability of the model was then compared to the outcome of model using field derived variables such as diameter at breast height of trees. The results show that the model using LiDAR derived variables better estimated the amount of CWD. It is concluded that LiDAR derived forest structural variables has the potential to predict the amount of downed CWD in Eucalyptus forest. 展开更多
关键词 CWD (Coarse woody debris) LiDAR (light detection and ranging) FOREST generalized liner model.
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Finding Areas at Risk from Floods in a Downpour Using the Lidar-Based Elevation Model 被引量:1
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作者 Sultana Nasrin Baby Colin Arrowsmith +3 位作者 Gang-Jun Liu David Mitchell Nadhir Al-Ansari Nahala Abbas 《Journal of Civil Engineering and Architecture》 2021年第1期1-16,共16页
Climate change can impact coastal areas in different ways,including flooding,storm surges,and beach erosion.Of these,flooding has a major impact on the operation of coastal drainage systems.This paper develops a new f... Climate change can impact coastal areas in different ways,including flooding,storm surges,and beach erosion.Of these,flooding has a major impact on the operation of coastal drainage systems.This paper develops a new flood screening model using a LiDAR based digital elevation model(DEM)to improve the implementation of Victorian’s coastal flooding risk assessment and management.Hydrological elevation models are directed towards protection from cloudbursts and applied to rising sea level.The aim is to simulate water flow on the ground and in streams,and the resulting accumulation of water in depressions of the blue spot using DEM.Due to the presence of pipes,watercourses,bridges and channels it was required that the DEM data to be lowered.The reservoirs of rain will prevent seawater from flowing across the stream channel into land.The rain drain will be open during normal sea levels to allow rain water in the river to move and flow in to the sea.Traditionally,geographic information system(GIS)assists with spatial data management,but lacks modelling capability for complex hydrology problems and cannot be relied upon by decision-makers in this sector.Functionality improvements are therefore required to improve the processing or analytical capabilities of GIS in hydrology.This research shows how the spatial data can be primarily processed by GIS adopting the spatial analysis routines associated with hydrology.The objective of this paper is to outline the importance of GIS technology for coastal flood management.Following a definition of the coastal flood,and,short description of its peculiarities and the urgency of its management,this paper describes the use of GIS technology in coastal flood management,its advantages and the consideration for accuracy.This is followed by the information and LiDAR data required for coastal flood management and the application area in coastal flood management.This paper method is presented to conduct a first high-resolution DEM screening to detect the degree and capacities of the sinks in the coastal landscape.When their capacities are established,the rain volumes received during a rainstorm from their coastal catchments are saved as attributes to the pour points.The conclusion emphases the importance of a geographical information system in coastal flood management for efficient data handling and analysis of geographically related data.Local governments at risk of coastal flooding that use the flood screening model can use to determine appropriate land use controls to manage long-term flood risk to human settlements. 展开更多
关键词 LIDAR flood-risk model builder blue spot model ESRI DEM
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Application of GIS for Mapping Rainwater-Harvesting Potential: Case Study Wollert, Victoria 被引量:1
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作者 Sultana Nasrin Baby Colin Arrowsmith Nadhir Al-Ansari 《Engineering(科研)》 2019年第1期14-21,共8页
Water is a basic normal asset for supporting the condition of life. Accessible water assets are feeling the squeeze because of expanding demand. Soon water, which we have depended upon to be accessible and an uncondit... Water is a basic normal asset for supporting the condition of life. Accessible water assets are feeling the squeeze because of expanding demand. Soon water, which we have depended upon to be accessible and an unconditional present of nature will turn into a rare product. Protection and conservation of water assets are desperately required. In many parts of Victoria, water supply to communities is limited. Rainwater harvesting systems can provide water at or near the point of demand. The systems can be owner and utility operated and managed. Rainwater collected using existing structures, i.e. rooftops, parking lots, playgrounds, parks, ponds, floodplains etc., has few negative environmental impacts compared to other technologies for water resources development. Rainwater is relatively clean and the quality is usually acceptable for many purposes with little or even no treatment. The physical and chemical properties of rainwater are usually superior to sources of groundwater that may have been subjected to contamination. The present study was intended to measure the rooftop rainwater harvesting potential using GIS techniques. The GIS examination utilized in this investigation was basically an efficient assessment of rooftop water collecting in the chose Wollert which is a suburb in Melbourne, Victoria. With the use of GIS it was conceivable to appraise the aggregate sum of water harvestable at the household level. It is very tedious work to assess the catchments available for rooftop rainwater harvesting. Here the roof surfaces are the catchments and GIS is employed to calculate the area of various types of roofs and their potential for planning for the area under study. As a result Eucalypt Estate Wollert has huge potential and can make above 179.11 litres water available per person per day throughout the year. 展开更多
关键词 RAINWATER HARVESTING POTENTIAL Measurement Rooftop GIS
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Climate Change Impacts on Water Resources of Ary Creek,Inverloch,Victoria
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作者 Sultana Nasrin Baby Colin Arrowsmith +1 位作者 Nahla Abbas Nadhir Al-Ansari 《Journal of Civil Engineering and Architecture》 2018年第10期727-740,共14页
Understanding urban wetland ecosystem services structure allows managers to base restoration efforts on multiple user end-benefits.Ary Creek can provide the coupled function of improving water quality and mitigating f... Understanding urban wetland ecosystem services structure allows managers to base restoration efforts on multiple user end-benefits.Ary Creek can provide the coupled function of improving water quality and mitigating floods through delayed stormwater flow.It is fundamental to identify areas surrounded by water for the safety of individual should in case the water level raise beyond a reasonable doubt and might cause a flood.For many years,the Ary Creek catchment in Inverloch has been flooding and causing great problems for the inhabitants as well as the environment.The procedure is to develop models of the area around the catchment or watershed using Victorian Coastal LiDAR and other input data from the GIS(geographic information system).This study uses the real-time simulation in ArcSWAT—ArcGIS 10.3 and 3D in ArcScene 10.3,and the variables obtained from the soil and water assessment tool ArcSWAT such as the land use,soil and slope are the parameters measured to induce the flood.When certain portions of the Hydrologic response unit HRU,land use,soil or slope is changed due to temporal adjustment and climate change,then the model can predict zones of low,moderate and high flood risk.The 3D simulations appear to produce a visual model for decision-making,planning,management,and mitigation.The simulation helps in determining the extent of the flood by using animation. 展开更多
关键词 MODELLING FLOOD SIMULATION LIDAR GIS ArcSWAT
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Test Vehicle Speed Error as a Function of Tire Pressure
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作者 Andriy Dyukov 《Journal of Traffic and Transportation Engineering》 2016年第2期102-106,共5页
The main objective of this study is to determine how speed errors of test vehicles depend on tire pressure. In order to achieve this, experiments were conducted to find out how tire pressure depends on driving speed a... The main objective of this study is to determine how speed errors of test vehicles depend on tire pressure. In order to achieve this, experiments were conducted to find out how tire pressure depends on driving speed and how distance measurements depend on tire pressure. It is demonstrated that hot tires might have their pressure increased by 6% at 110 km/h speed relative to nominal tire pressure. Subsequently, experiments conducted on a surveyed test track proved that hot tires might increase speed measurement errors by 0.03%, whereas under-inflated tires might cause several times higher speed errors, It is critical that test vehicles involved in speed measurements have nominal tire pressure when tires are cold. In such instances, the uncertainty of speed measurements component related to tire pressure is relatively low. This research allowed quantifying the tire pressure error component for a specific test vehicle, while the experimental approach might be used for any other vehicles. 展开更多
关键词 SPEED measurement UNCERTAINTY TIRE pressure.
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Spatial Decision Support System for Coastal Zone Management under a Changing Climate in Victoria, Australia
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作者 Sultana Nasrin Baby Colin Arrowsmith +1 位作者 Nadhir Al-Ansari Nahlah Abbas 《Engineering(科研)》 2018年第10期637-642,共6页
The ultimate aim of using spatial datasets and spatial data modelling is focused on enabling a sustainable environment by bringing the public policies into practice. The consequence will be sustainable spatially aware... The ultimate aim of using spatial datasets and spatial data modelling is focused on enabling a sustainable environment by bringing the public policies into practice. The consequence will be sustainable spatially aware strategic planning for all levels of Australian government. Geographical Information Systems (GIS) are the platform that can serve this aim provided that model, current process and spatial datasets are fit for purpose. To bring public policy into practice a broad range of knowledge from different disciplines is needed. Most decision making processes are pressured in terms of time and driving forces and also the process is beyond the knowledge of individuals in the various disciplines. There is a need for immediate uptake models and tools which are relevant to the target subject that will facilitate this decision making process. This paper focuses on realizing the utility in spatial data and spatial data handling in order to help climate change adaptation programs at local government level. Web-based mapping tools can assist planners prepare for the changing climate conditions in Bass Coast Shire Council. The GIS team has gathered data from various climate research organizations to understand projections of what different climate scenarios might look like over the next 100-year period. From this website demo it is hoped that the user will understand how the tool works, background information on different GIS platforms, access to interactive mapping, online geospatial analysis tools, videos, open source resource, sea level tools, modelling, 3D visualization and direct download access to various planning and natural resource data sets relating to environment management. Some results from our elevation data analyses through these Web map visualization tools are provided. 展开更多
关键词 SPATIAL Modelling GIS 3D Visualisation WEB-BASED CLIMATE
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Prospects for Improving the Operational Seasonal Prediction of Tropical Cyclone Activity in the Southern Hemisphere
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作者 Yuriy Kuleshov Yan Wang +2 位作者 Jemishabye Apajee Robert Fawcett David Jones 《Atmospheric and Climate Sciences》 2012年第3期298-306,共9页
Tropical cyclones (TCs) are the most destructive weather phenomena to impact on tropical regions, and reliable predicttion of TC seasonal activity is important for preparedness of coastal communities in the tropics. I... Tropical cyclones (TCs) are the most destructive weather phenomena to impact on tropical regions, and reliable predicttion of TC seasonal activity is important for preparedness of coastal communities in the tropics. In investigating prospects for improving the skill of TC seasonal prediction in the South Indian and South Pacific Oceans, including the Australian Region, we used linear regression to model the relationship between the annual number of cyclones and three indices (SOI, NI?O3.4 and 5VAR) describing the strength of the El Ni?o-Southern Oscillation (ENSO). The correlation between the number of Australian Region (90?E - 160?E) TCs and the indices was strong (3-month 5VAR ?0.65, NI?O3.4 ?0.62 and SOI +0.64), and a cross-validation assessment demonstrated that the models which used July-August-September indices and the temporal trend as the predictors performed well. The predicted number of TCs in the Australian Region for 2010/2011 and 2011/2012 seasons was 14 (11 recorded) and 12, respectively. We also found that the correlation between the numbers of TCs in the western South Indian region (30?E to 90?E) and the eastern South Pacific region (east of 170?E) and the indices was weak, and it is therefore not sensible to build linear regression forecast models for these regions. We conclude that for the Australian Region, the new statistical model provides prospects for improvement in forecasting skill compared to the statistical model currently employed at the National Climate Centre, Australian Bureau of Meteorology. The next step towards improving the skill of TC seasonal prediction in the various regions of the Southern Hemisphere will be undertaken through analysis of outputs from the dynamical climate model POAMA (Predictive Ocean-Atmosphere Model for Australia). 展开更多
关键词 TROPICAL CYCLONES SEASONAL Prediction AUSTRALIAN Region
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