Daniel Z. Sui

From GIS to neogeography: ontological implications and theories of truth

Neogeography has emerged as a descriptive and analytical tool for large numbers of people outside of academia, a process catalyzed by digital mapping technologies and the social networking practices of Web 2.0. This article examines the ontological and epistemological implications of this transition. It argues that neogeography has democratized GIS practices, facilitated the adoption of relational views of space and place, and broadened the ontological scope of GIS. Neogeography also poses epistemological challenges to the dominant theory of truth, in particular advancing a shift away from the correspondence model of truth toward consensus and performative interpretations. While recognizing the multiple unintended consequences of neogeographical practices, neogeography is held to be as a useful means for charting geographic space in light of intense postmodern time–space compression.

Spatial influence vs. community influence: modeling the global spread of social media

In this paper we seek to understand and model the global spread of social media. How does social media spread from location to location across the globe? Can we model this spread and predict where social media will be popular in the future? Toward answering these questions, we develop a probabilistic model that synthesizes two conflicting hypotheses about the nature of online information spread: (i) the spatial influence model, which asserts that social media spreads to locations that are close by; and (ii) the community affinity influence model, which asserts that social media spreads between locations that are culturally connected, even if they are distant. Based on the geospatial footprint of 755 million geo-tagged hashtags spread through Twitter, we evaluate these models at predicting locations that will adopt hashtags in the future. We find that distance is the single most important explanation of future hashtag adoption since hashtags are fundamentally local. We also find that community affinities (like culture, language, and common interests) enhance the quality of purely spatial models, indicating the necessity of incorporating non-spatial features into models of global social media spread.

Campaign extraction from social media

In this manuscript, we study the problem of detecting coordinated free text campaigns in large-scale social media. These campaigns—ranging from coordinated spam messages to promotional and advertising campaigns to political astro-turfing—are growing in significance and reach with the commensurate rise in massive-scale social systems. Specifically, we propose and evaluate a content-driven framework for effectively linking free text posts with common “talking points” and extracting campaigns from large-scale social media. Three of the salient features of the campaign extraction framework are: (i) first, we investigate graph mining techniques for isolating coherent campaigns from large message-based graphs; (ii) second, we conduct a comprehensive comparative study of text-based message correlation in message and user levels; and (iii) finally, we analyze temporal behaviors of various campaign types. Through an experimental study over millions of Twitter messages we identify five major types of campaigns—namely Spam, Promotion, Template, News, and Celebrity campaigns—and we show how these campaigns may be extracted with high precision and recall.

True lies in geospatial big data: detecting location spoofing in social media

ABSTRACT Location spoofing refers to the act of intentionally falsifying one’s actual locational information. The proliferation of location spoofing in recent years has stirred debate about the reliability and convenience of user-generated geospatial contents and the use of location spoofing as an effective countermeasure to protect individual geo-privacy and national security. However, these polarized views do not contribute to a holistic understanding of location spoofing. As of today, we still lack a robust method for detecting location spoofing and comprehending its multifaceted implications. The goal of this article is to develop a quantitative approach for detecting location spoofing and a qualitative approach for probing the possible motivations of this growing practice and its inherent uncertainties. We tested our Bayesian time geographic approach for detection using millions of geo-tagged tweets – a major source of big data for studying the spatial-temporal patterns of human activities. Our results indicate that the proposed approach can successfully detect certain types of location spoofing and more research is needed about the detection and implications of location spoofing in the age of wide-spread fake news. Rather than simply dismissing location spoofing as a technical nuisance, this article calls the GIScience community to confront this thorny issue head-on, especially when any arguments or policies are drawn from geospatial big data. Only then can we promote more effective and trustworthy uses of geospatial big data in society at large.

Modeling impacts of globalization on desakota regions: a case study of Taipei Metropolitan Area

Rapid urbanization in Asia challenges conventional urban models developed in the West in terms of economic globalization and local development. The new desakota model proposed by McGee and Ginsburg describes unique spatial structure in Asian urbanization. Although urban morphology is highlighted, urbanization processes driven by globalization and local economies are not emphasized in this descriptive model. To elaborate on how economic globalization influences urbanization processes and shapes unique spatial features in Asia, this study adopts cellular automata to develop a GIS-based urban model and simulate how foreign direct investments (FDIs), an important indicator of economic globalization, influence the local economy and the evolution of spatial structures with various levels of foreign flux. The Taipei case study confirms that growing FDIs and service activities are key factors stimulating the growth of desakota regions and the formation of a mega-urban region during the urbanization process.

Emerging GIS themes and the six senses of the new mind: is GIS becoming a liberation technology?

The past 20 years have witnessed the emergence of a plethora of research themes in GIS that are quite different from conventional GIS practices. This article develops a preliminary framework to loosely knit together the diverse intellectual threads for the emerging GIS themes. It is found that the framework for the six senses of the whole new mind (design, story, symphony, empathy, play and meaning) captures the six major emerging GIS themes remarkably well. Conventional GIS practices have been predominantly concentrating on automated cartography/map-making, spatial modelling, geocomputation and database development with the goal for efficiency, which tend to be closely associated with the left-side/slow thinking capabilities of the human brain. In contrast, the emerging GIS themes focus more on geonarratives, qualitative/mixed methods, storytelling and synthesis with the goal for achieving equity and social justice, which tend to be more closely associated with the right-side/fast thinking capabilities of the human brain. Evidently, these new GIS practices have the potential to enable GIS users to transcend what Heidegger called the enframing nature of technology and motivate them to explore new areas of enquiry with greater sensitivities to the social and political dimensions of GIS application. Increasingly, these emerging GIS practices are transforming GIS into a liberation technology that continues empowering GIS users in their quest for a better, more equitable and sustainable world. These emerging themes also pose new research and educational challenges for the GIS community in the years ahead.

Integrating the normative with the positive dimension of the new science for cities: A geodesign-based framework for Cellular Automata modeling

Cellular Automata (CA) models are powerful simulation tools to study complex urban systems. Although there has been considerable amount of CA-based modeling work reported in the literature, few have been used as actual planning or policy making tools. The goal of this research aims to address the problem of “unapplicable CA models” by combining CA models with the framework of geodesign. Inspired by Battys new science of cities, we put forward a geodesign-based framework for CA modeling to integrate the positive and normative dimension of the new science of cities as envisioned by Batty. Instead of merely applying CA models to positive urban studies, which typically requires more accurate predictions, we advocate the integration of positive (i.e. urban simulation) and normative (i.e. design) city science via the application of CA modeling to geodesign. By linking CA simulation with the geodesign framework, a geodesign-based CA model is developed and six urban design scenarios are integrated into the model, to test the urban growth impacts of these scenarios and generate a new design scenario accordingly. Using a case study of urban growth in Changping District, Beijing, we demonstrate that the normative and the positive dimension of Battys new science for cities can be integrated. Geodesign, as a new conceptual framework, is helpful for streamlining the CA modelling process to evaluate different design scenarios and design new scenarios. In return, CA models could also contribute to the geodesign process by offering a tool for simulating and evaluating impacts of different design scenarios on urban growth.

GIS as Media Through the Geoweb

This chapter first traces the evolution of GIS from its earlier focus on automated cartography (organizing geospatial information) to its current status as media, with an emphasis on the geoweb (organizing information geospatially). Using Adams’ (2009) tetradic framework on geographies of media, this chapter then presents a preliminary analysis on geographies of media and mediated geographies as manifested through the ever-growing geoweb in the age of big data and open science. As the geoweb increasingly becomes both the container of and the contained by spaces and places, fruitful research can be carried out at the intersection of GIScience and communication geography by examining spaces and places as both contents and contexts for the geoweb.