May Yuan

• Ph.D. in Geography (1994), SUNY Buffalo
• Professor (Full) at The University of Texas at Dallas

Due to their sparse distribution and placement in open areas, fixed air-quality-monitoring stations fail to characterize the effect of contextual factors such as buildings on the dispersion of PM2.5. This study evaluated the effects of building morphology on PM2.5 dispersion in a pedestrian-friendly area on the University of Texas at Dallas campus,...

In-person social events bring people to places, while people and places influence where and what social events occur. Knowing what people do and where they build social relationships gives insights into the distribution and availability of places for social functions. We developed a Bayesian Network model, integrating points of interest (POIs) and...

INTRODUCTION Understanding impact of environmental properties on Alzheimer's disease (AD) is paramount. Spatial complexity of one's routinely navigated environment is an important but understudied factor. METHODS A total of 660 older adults from National Alzheimer's Coordinating Center (NACC) dataset were geolocated and environmental complexity in...

Conventional spatiotemporal methods take frequentist or density-based approaches to map event clusters over time. While these methods discern hotspots of varying continuity in space and time, their findings overlook locations of routine occurrences where the geographic context may contribute to the regularity of event occurrences. Hence, this resea...

The Annual Meeting of the American Association of Geographers (AAG) in 2023 marked a five-year milestone since the first Geospatial Artificial Intelligence (GeoAI) Symposium was held at AAG in 2018. In the past five years, progress has been made while open questions remain. In this context, we organized an AAG panel and invited five panellists to d...

Fine particulate matter, also known as PM2.5, has many adverse impacts on human health. However, there are few ground monitoring stations measuring PM2.5. Satellite data help fill the gaps in ground measurements, but most studies focus on estimating daily PM2.5 levels. Studies examining the effects of environmental exposome need accurate PM2.5 esti...

Background Rural-urban differences and spatial navigation deficits have received much attention in Alzheimer’s Disease research. While individual environmental and neighborhood factors have been independently investigated, their integrative, multifactorial effects on Alzheimer’s diagnosis have not. Here we explore this “environmental complexity” fo...

In this commentary, we describe the current state of the art of points of interest (POIs) as digital, spatial datasets, both in terms of their quality and affordings, and how they are used across research domains. We argue that good spatial coverage and high-quality POI features — especially POI category and temporality information — are key for cr...

Concepts of scale are at the heart of diverse scientific endeavors that seek to understand processes and how observations and analyses influence our understanding. While disciplinary discretions exist, researchers commonly devise spatial, temporal, and organizational scales in scoping phenomena of interest and determining measurements and represent...

This essay discusses theoretical perspectives in GIScience in representing and computing geographic information. Grounding the discussion is the need for new ways of thinking about new facts. Information and geospatial technologies continue acquiring new facts of various kinds. New ways of thinking about these new facts are essential to theoretical...

Geospatial research has long centered around objects. While attention to events is growing rapidly, events remain objectified in spatial databases. This paper aims to highlight the importance of events in scientific inquiries and overview general event-based approaches to data modeling and computing. As machine learning algorithms and big data beco...

The rise of Geographic Information Systems (GIS) technologies has been producing powerful tools for spatial data processing, management, analysis, modeling, and visualization. While supporting many tasks, GIS technologies have evoked new thinking and advanced intellectual inquiries in geography. Technological advances in other fields often stimulat...

The United Nations General Assembly adopted the 2030 Agenda for sustainable development goal in 2015 for a prosperous and inclusive future for all. Reflecting on the contributions of IJGIS publications to sustainability, this editorial draws the intellectual relevance of GIScience to the UN sustainable development goals (SDGs). GIScience, with its...

This chapter reviews cartographic and phenomenological views of landscape; argues for opportunities to traverse freely between the two seemly disjoint perspectives to landscape understanding, and discusses four geospatial approaches to enrich historical landscapes geographically. Innovations and advances in Geographical Information Science and Tech...

Traditional Geographic Information Systems (GIS) represent the environment under reductionist thinking, which disaggregates a geographic environment into independent geographic themes. The reductionist approach makes the spatiotemporal characteristics of geo-features explicit, but neglects the holistic nature of the environment, such as the hierarc...

The contrast of space and place has long been an active topic of scholarly discussions in many disciplines. While spatial analysis enjoys a multitude of quantitative methods, the study of place remains mostly conceptual and descriptive. This paper expands upon the rich concepts of place in the literature to propose a quantitative framework for plac...

We propose a novel approach to network-based event likelihood modeling that estimates the probabilities of event occurrences on a network and identifies the influences of site and situation characteristics. Our premise is that the occurrences of events that involve human activities are subject to site and situational characteristics, and an underst...

This article highlights the key intellectual development in human dynamics research, examines the modeling emphases in publications, and argues for research directions in need. Human dynamics research is discussed in two broad directions: spacing time and timing space, to model human activities and interactions. Time is essential to human dynamics...

Nuweiba sits on a flood plain between the Sinai Mountain and the Gulf of Aqaba. Flash floods pose significant threats to socio-economic development in the region. This study assessed flash floods risk in the greater Nuweiba area in support of mitigation planning. Our approach evaluated topographic, hydrological, and geological factors holistically...

The International Journal of Geographic Information Science (IJGIS), established in 1987, is the first academic journal devoted solely to Geographical Information Science (GIS) research. This editorial highlights milestones of the journal development and its influences on the field. IJGIS research articles and special issues have been effective in...

Cloud computing has become ubiquitous in modern life, and research. Your email is stored on the cloud and is accessible from anywhere on any smart device. Your music is streamed from a cloud source. You can store your images and videos on a cloud drive and expand the size of the drive instantly for a relatively small cost. You are increasingly usin...

Space-time GIS emerged in the early 1990s to incorporate temporal information and analytical functions so that GIS technology could handle both spatial and temporal data. To do so, GIS technology has to embrace spatial and temporal data throughout the processes of conceptualization, representation, computation, and visualization. Conceptualization...

Improving solar radiation models is critical for supporting the increase in solar energy usage and modeling ecosystem dynamics. However, coarse spatial resolutions of solar radiation models overlook the impacts resulting from spatial variability of clouds at meso- and micro-scales. To address this problem, Moderate Resolution Imaging Spectroradiome...

Cloud Computing in Ocean and Atmospheric Sciences provides the latest information on this relatively new platform for scientific computing, which has great possibilities and challenges, including pricing and deployments costs and applications that are often presented as primarily business oriented. In addition, scientific users may be very familiar...

This paper summarizes the discussions related to the panel “Contributions of GIScientists (or GIScience) over the past Twenty Years” at the 2015 Vespucci Institute. Reflections about the past not only provide an account of what occurred, but also may serve as a basis for comparison when in the future somehow related scenarios arise. Such histories...

Location-aware devices have enabled the recording of personal whereabouts at fine spatial and temporal resolutions. These temporal sequences of personal locations provide unprecedented opportunities to explore patterns of life through space-time analytics of movement and stops of individuals. At a disaggregated level, patterns of life reveal the ac...

Very few of current eddy detection algorithms are capable of identifying multieddy structures resulted from interactions among eddies. In this study, we improve our previous hybrid detection (HD) algorithm by incorporating a new criterion to better identify multieddy structures from satellite altimeter data. The criterion defines an aspect ratio to...

For educational or non-commercial use only. Location-aware devices have enabled the recording of personal whereabouts at fine spatial and temporal resolutions. These temporal sequences of personal locations provide unprecedented opportunities to explore patterns of life through space-time analytics of movement and stops of individuals. At a disaggr...

A>Introduction<\> Maps have long been one of the key tools to represent the landscape within which histories occurred. While being static, maps present the spatial dimension of historical data and reveal spatial associations among spatial features of interest. Much research in spatial histories or historical geographical information systems (GIS) r...

eds). Mapping and Modeling Weather and Climate with GIS. Esri Press. Weather and climate information is innately geospatial. Maps have long been essential to meteorologists and climatologists in their research and operations. Edmond Halley included a map of the trade winds and monsoons in an article he wrote in 1686 (Halley 1686). The map is credit...

The so-called Big Data Challenge poses not only issues with massive volumes of data, but issues with the continuing data streams from multiple sources that monitor environmental processes or record social activities. Many statistics tools and data mining methods have been developed to reveal embedded patterns in large data sets. While patterns are...

This paper discusses philosophical and methodological considerations of space–time representation and analytics. Central to our premise is that how we conceptualize space and time has profound influence on the way in which we represent and analyse spatiotemporal data. Four approaches in space–time representation are discussed based on two sets of s...

Historical GIS is now a vibrant area of research that applies mapping and spatial methods (both quantitative and qualitative) to study the geographies of the past or the influence of geography on history. A quick search on Google Scholar with keywords "historical GIS" returned over 35,000 results 1 . While historians consider time as the key to org...

The so-called Big Data Challenge poses not only issues with massive volumes of data, but issues with the continuing data streams from multiple sources that monitor environmental processes or record social activities. Many statistics tools and data mining methods have been developed to reveal embedded patterns in large data sets. While patterns are...

Results are compared of using arithmetic averaging and kriging to estimate daily area-average rainfall during the summer 1991 Convection and Precipitation/Electrification Experiment (CaPE) in central Florida, where convective rainstorms often produce rain-fields of high spatial variability. Four kriging methods were applied: ordinary kriging using...

This paper proposes an ontology-enabled framework for a geospatial problem-solving environment (geospatial PSE) that allows collaboration among Web-service providers, domain experts, and solution seekers to semantically discover and use geographic information services (GI services) to solve a target class of geospatial problems. The framework conta...

We use evidence from a quasi-experiment – the shipping of radioactive spent nuclear fuel by train through South Carolina – to assess whether many years of incident-free transport of nuclear waste no longer negatively affects market valuation of properties along the route. Using Charleston County (SC) property sales data over 13 years we find, to th...

The so-called Big Data Challenge poses not only issues with massive volumes of data, but issues with the continuing data streams from multiple sources that monitor environmental processes or record social activities. Many statistics tools and data mining methods have been developed to reveal embedded patterns in large data sets. While patterns are...

This research develops a new temporal Geographic Information System (GIS) framework and applies it to compare General Circulation Model (GCM) products and reanalysis datasets in order to discern differences in patterns and locations of change as a proof of concept. The proposed framework incorporates the concept of kinematics to represent the movem...

Development of ecosystem-based fisheries management models depends, to a large extent, on the availability of trophic interaction data. These models could address ecological questions, examine ecosystem trophic structure, and be used in placement analysis for marine protected areas, among other uses. Many studies on fish trophic interactions have b...

A kinematics-based GIS methodology is applied to represent and analyze spatiotemporal patterns and pattern transitions in very large data sets. The study demonstrates that the kinematics approach is able to discern transitional patterns from a continuous field of geographic properties over time by defining objects through thresholds and analyzing t...

Background/Question/Methods Preservation of historical data is essential toward an understanding of the cumulative effects of anthropogenic impacts on marine ecosystems, such as the shifting baselines syndrome or trophic cascades. Historic data on marine organisms are very scattered (much in hard copy only) and in many cases highly susceptible to...

The central themes emerged from our discussions about climate change and hazards that imply significant challenges to advancing scholary knowledge on the one hand and to fostering greater public understanding on the other. These themes relate 1) the uncertainty of how global climate is changing, particulary with respect to anticipated regional or l...

Geographic Information Systems have been traditionally designed to account for geospatial dimensions of information. Many studies on temporal GIS offer data frameworks or indexing structures to incorporate time into spatial databases. While time-stamped or time-indexed geospatial data enable GIS queries with specified time, elevating space-time to...

Central to temporal Geographical Information systems (GIS) research is representation and analysis of temporality in spatial databases. Temporality can be characterized by change, motion, and periodicity, but to date, most temporal GIS research advances contribute to representing and analyzing spatially discrete constructs of amandant vectors, geos...

Contemporary GIS can handle static spatial data for querying and visual representation, but the temporal dimension remains a challenge. This paper addresses the need for a dynamic GIS capable of managing complex data types. The design relies on a representation of the theoretical spatiotemporal primitive known as the ‘geo-atom’. This paper proposes...

Determination of effective ways to reduce vulnerability from tornadoes is one of the fundamental drivers for tornado research. This study analyzes spatial vulnerability in the context of past tornado events with aims to enhance the understanding of tornado casualties in Oklahoma and Northern Texas. Many previous studies have provided insight on how...

Sodium (Na) is uncommon in plants but essential to the metabolism of plant consumers, both decomposers and herbivores. One consequence, previously unexplored, is that as Na supplies decrease (e.g., from coastal to inland forests), ecosystem carbon should accumulate as detritus. Here, we show that adding NaCl solution to the leaf litter of an inland...

Light Detection and Ranging (lidar) technology enables cost-effective rapid production of digital models that capture topography and vertical structures of surface features at a fine spatial resolution. The capability has promoted lidar applications for mapping terrain, buildings, forest stands, and coastal features that cannot be adequately captur...

From a public health perspective, a healthier community environment correlates with fewer occurrences of chronic or infectious diseases. Our premise is that community health is a non-linear function of environmental and socioeconomic effects that are not normally distributed among communities. The objective was to integrate multivariate data sets r...

Temporal Geographic Information Systems (GIS) technology has been a top research subject since late the 1980s. Langran's Time in Geographic Information Systems (Langran, 1992) sets the first milestone in research that addresses the integration of temporal information and functions into GIS frameworks. Since then, numerous monographs, books, edited...

Computational thinking has enabled many new scientific discoveries through the development of new algorithms, simulation models, visualization, and novel approaches to summarize the patterns and structure of complex systems. In contrast to the natural sciences, the historical social sciences (anthropology/archaeology, economics, geography, history,...

Remote sensing of a natural disaster&apos;s damage offers an exciting backup and/or alternative to traditional means of on-site damage assessment. Although necessary for complete assessment of damage areas, ground-based damage surveys conducted in the aftermath of natural hazard passage can sometimes be potentially complicated due to on-site diffic...

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Remote sensing techniques have been shown effective for large-scale damagesurveys after a hazardous event in both near real-time or post-event analyses. The paperaims to compare accuracy of common imaging processing techniques to detect tornadodamage tracks from Landsat TM data. We employed the direct change detection approachusing two sets of imag...

SynonymsSpatio-temporal information systems; Spatio-temporal informatics; Process; Snapshots; Matrices, geographic; Interaction, space-time; Timestamps; Event; Movement; Activity; Ontology, spatio-temporal; SNAP; SPAN; Reasoning, spatio-temporalDefinitionGeographic information is inherently spatial and temporal. Geographic applications often demand...

Platinum Sponsors * KU Department of Geography * KU Institute for Policy & Social Research Gold Sponsors * State of Kansas Data Access and Support Center (DASC) * KU Libraries GIS and Scholar Services * KU Transportation Research Institute * Wilson & Company (formerly Western Air Maps) Silver Sponsors * Bartlett & West * KU Biodiversity Institute *...

Effective information analytics is required to decipher massive data output from general circulation models (GCMs) and other spatially explicit models of environmental dynamics. Common approaches with discrete space or time constructs overlook the fundamental characteristics of continuity in dynamics. We propose a representation that centers on the...

This paper discusses the drivers and observables of geographic dynamics as well as GIS approaches to facilitate geographic dynamics understanding. Geographic domains exhibit diverse dynamics across multiple spatiotemporal scales. Such diverse and complex geographic dynamics poses challenges to connect relevant information and infer the underlined m...

Geographic representation has become more complex through time as researchers have added new concepts, leading to apparently endless proliferation and creating a need for simplification. We show that many of these concepts can be derived from a single foundation that we term the atomic form of geographic information. The familiar concepts of contin...

This paper aims to explore the analysis of climate patterns embedded in the Global Climate Data Sets generated by the Community Climate System Model (CCSM) for the 4 th Assessment Report of the Intergovernmental Report for Climate Change (IPCC). A Geographic Information Systems (GIS) approach is taken to examine spatiotemporal correlates among clim...

While some geographic phenomena hold uniform properties, such as land-use zones, many geographic phenomena are distributed such that their properties vary across an extended area. While such distributed phenomena are best represented as continuous surfaces, individual objects (or features) often emerge among clusters of high or low values in a fiel...

The increased availability of spatiotemporal data collected from satellite imagery and other remote sensors provides opportunities for enhanced analysis of geographic phenomena. Much of the new data includes regular snapshots of the environment. Comparison of these snapshots can provide information about changes to the phenomena of interest. Howeve...

No Abstract Available.

Geographical diversity gradients, even among local communities, can ultimately arise from geographical differences in speciation and extinction rates. We evaluated three models--energy-speciation, energy-abundance, and area--that predict how geographic trends in net diversification rates generate trends in diversity. We sampled 96 litter ant commun...

A representation is a means to communicate geographic information, and is also a binary structure in a computer or electronic storage medium that corresponds with an object, measurement, or phenomenon in the world. The representation chosen for a geographic phenomenon has a profound impact on interpretation and analysis. The selection of informatio...

Knowledge discovery technology has emerged as an empowering tool in the development of the next generation database and information systems through its abilities to extract new, insightful information embedded within large heterogeneous databases and to formulate knowledge. A KDD process includes “data warehousing, target data selection, cleaning,...

Accurate predictions of air quality and atmospheric dispersion at high spatial resolution rely on high fidelity predictions of mesoscale meteorological fields that govern transport and turbulence in urban areas. However, mesoscale meteorological models do not have the spatial resolution to directly simulate the fluid dynamics and thermodynamics in...

Gradients of species richness (S; the number of species of a given taxon in a given area and time) are ubiquitous. A key goal in ecology is to understand whether and how the many processes that generate these gradients act at different spatial scales. Here we evaluate six hypotheses for diversity gradients with 49 New World ant communities, from tu...

Remote sensing (RS) and geographic information systems (GIS) techniques are applied to high-resolution satellite imagery to determine characteristics of tornado damage from the 3 May 1999 tornado outbreak. Three remote sensing methods, including principal components analysis, normalized difference vegetation index (NDVI) analysis, and NDVI change a...

This chapter presents the fundamentals of spatiotemporal information and queries that are central to understanding of the dynamic world. A typology of spatiotemporal information queries is developed to summarize distinct dimensionalities of inquired information in space and time. The typology distinguishes 11 query types: attribute queries, 3 types...