Guoray Cai

Geovisualization for knowledge construction and decision support

Geovisualization is both a process for leveraging the data resources to meet scientific and societal needs and a research field that develops visual methods and tools to support a wide array of geospatial data applications. While researchers have made substantial advances in geovisualization over the past decade, many challenges remain. To support real-world knowledge construction and decision making, some of the most important challenges involve distributed geovisualization - that is, enabling geovisualization across software components, devices, people, and places.

Speech-gesture driven multimodal interfaces for crisis management

Emergency response requires strategic assessment of risks, decisions, and communications that are time critical while requiring teams of individuals to have fast access to large volumes of complex information and technologies that enable tightly coordinated work. The access to this information by crisis management teams in emergency operations centers can be facilitated through various human-computer interfaces. Unfortunately, these interfaces are hard to use, require extensive training, and often impede rather than support teamwork. Dialogue-enabled devices, based on natural, multimodal interfaces, have the potential of making a variety of information technology tools accessible during crisis management. This paper establishes the importance of multimodal interfaces in various aspects of crisis management and explores many issues in realizing successful speech-gesture driven, dialogue-enabled interfaces for crisis management. This paper is organized in five parts. The first part discusses the needs of crisis management that can be potentially met by the development of appropriate interfaces. The second part discusses the issues related to the design and development of multimodal interfaces in the context of crisis management. The third part discusses the state of the art in both the theories and practices involving these human-computer interfaces. In particular, it describes the evolution and implementation details of two representative systems, Crisis Management (XISM) and Dialog Assisted Visual Environment for Geoinformation (DAVE/spl I.bar/G). The fourth part speculates on the short-term and long-term research directions that will help addressing the outstanding challenges in interfaces that support dialogue and collaboration. Finally, the fifth part concludes the paper.

Enabling collaborative geoinformation access and decision‐making through a natural, multimodal interface

Current computing systems do not support human work effectively. They restrict human–computer interaction to one mode at a time and are designed with an assumption that use will be by individuals (rather than groups), directing (rather than interacting with) the system. To support the ways in which humans work and interact, a new paradigm for computing is required that is multimodal, rather than unimodal, collaborative, rather than personal, and dialogue‐enabled, rather than unidirectional. To address this challenge, we have developed an approach for designing natural, multimodal, multiuser dialogue‐enabled interfaces to geographic information systems that make use of large‐screen displays and integrated speech–gesture interaction. After outlining our goals and providing a brief overview of relevant literature, we introduce the Dialogue‐Assisted Visual Environment for Geoinformation (DAVE_G). DAVE_G is being developed using a human‐centred systems approach that contextualizes development and assessment in the current practice of potential users. In keeping with this human‐centred approach, we outline a user task analysis and associated scenario development that implementation is designed to support (grounded in the context of emergency response), review our own precursors to the current prototype system and discuss how the current prototype extends upon past work, provide a detailed description of the architecture that underlies the current system, and introduce the approach implemented for enabling mixed‐initiative human–computer dialogue. We conclude with a discussion of goals for future research.

The minimum augmentation of any graph to a K-edge-connected graph

For a graph G0 = (V, E0) and an integer K, how many edges are needed for augmenting G0 to a K-edge-connected graph? Results in the literature have answered this in several special cases such as when G0 is a tree, or when K = 2. In this paper, we settle the problem in the general case where G0 can be any multigraph and K can be any positive integer. We obtained both good characterization and good algorithm for the problem. Applications of our algorithm are suggested in designing a reliable network aiming at the most effective use of exising network.

Contextualization of Geospatial Database Semantics for Human---GIS Interaction

Human interactions with geographical information are contextualized by problem-solving activities which endow meaning to geospatial data and processing. However, existing spatial data models have not taken this aspect of semantics into account. This paper extends spatial data semantics to include not only the contents and schemas, but also the contexts of their use. We specify such a semantic model in terms of three related components: activity-centric context representation, contextualized ontology space, and context mediated semantic exchange. Contextualization of spatial data semantics allows the same underlying data to take multiple semantic forms, and disambiguate spatial concepts based on localized contexts. We demonstrate how such a semantic model supports contextualized interpretation of vague spatial concepts during human–GIS interactions. We employ conversational dialogue as the mechanism to perform collaborative diagnosis of context and to coordinate sharing of meaning across agents and data sources.

Supporting Group Work in Crisis Management: Visually Mediated Human — GIS — Human Dialogue

Geospatial information is a fundamental component of many crisis management activities. However, current geospatial technologies do not support work by crisis management personnel, most of whom are not technology specialists—a key impediment is that the technologies require the user to learn the systems language. In addition, geospatial technologies are not ‘collaboration friendly’—they impede rather than facilitate group work. In this paper we address both issues by presenting (1) a theoretical framework for understanding the roles of visual mediation in map-supported human–human dialogues, and (2) a computational approach for enabling such roles in collaborative spatial decisionmaking contexts. Building upon our initial implementation of a map-mediated collaborative environment, the DAVE_G system [a natural, multimodal, dialogue-enabled interface to geographical information systems (GIS)], we model human–GIS and human–GIS–human dialogues as complex visual-cognitive signification processes in which maps become dynamic facilitators. Using a scenario simulating two crisis managers dealing with a major nuclear release event, we demonstrate how visual display (in DAVE_G) actively mediates human–human dialogue directed to situation assessment and action planning in real applications.

A query-aware document ranking method for geographic information retrieval

Geographically oriented search must consider both the thematic and geographic dimensions of relevance when matching documents to queries. We propose a dynamic document ranking scheme to combine the thematic and geographic relevance measures on a per-query basis. Query specificity is introduced to determine the relative weights of different sources of ranking evidence for each query. A preliminary evaluation comparing with human judgment shows that our method to distinguish different types of geo-referenced queries based on query specificity is promising to address the issue of relevance combination in GIR document ranking. In addition, we explore the possibility of using Dempster-Shafers theory to combine the two different sources of ranking evidence.

Communicating Vague Spatial Concepts in Human-GIS Interactions: A Collaborative Dialogue Approach

Natural language requests involving vague spatial concepts are not easily communicated to a GIS because the meaning of spatial concepts depends largely on the contexts (such as task, spatial contexts, and user’s personal background) that may or may not be available or specified in the system. To address such problems, we developed a collaborative dialogue approach that enables the system and the user to construct shared knowledge about relevant contexts. The system is able to anticipate what contextual knowledge must be shared, and to form a plan to exchange contextual information based on the system’s belief on who knows what. To account those user contexts that are not easily communicated by language, direct feedback approach is used to refine the system’s belief so that the intended meaning is properly grounded. The approach is implemented as a dialogue agent, GeoDialogue, and is illustrated through an example dialogue involving the communication of the vague spatial concept near.

Natural Conversational Interfaces to Geospatial Databases

Natural (spoken) language, combined with gestures and other human modalities, provides a promising alternative for interacting with computers, but such benefit has not been explored for interactions with geographical information systems. This paper presents a conceptual framework for enabling conversational humanGIS interactions. Conversations with a GIS are modeled as human-computer collaborative activities within a task domain. We adopt a mental state view of collaboration and discourse and propose a plan-based computational model for conversational grounding and dialogue generation. At the implementation level, our approach is to introduce a dialogue agent, GeoDialogue , between a user and a geographical information server. GeoDialogue actively recognizes user’s information needs, reasons about detailed cartographic and database procedures, and acts cooperatively to assist user’s problem solving. GeoDialogue serves as a semantic ‘bridge’ between the human language and the formal language that a GIS understands. The behavior of such dialogue-assisted human-GIS interfaces is illustrated through a scenario simulating a session of emergency response during a hurricane event.

Extending Distributed GIS to Support Geo-Collaborative Crisis Management

Abstract Crises are often complex, geographical scale problems that require professionals to work in teams while dealing with a large amount of geographic information for decision making. However, current geospatial technologies do not directly support group entities working with geographic information–they impede rather than facilitate human-human collaborations and communication. Towards the goal of making GIS “collaboration-friendly,” this paper explores the potentials of extending distributed GIS with groupware and intelligent communication agents to support geo-collaborative crisis management by teams. Members of such a team are often geographically distributed and play different roles. In addition to the architectural choice, special attention was given to the computational approach to enable collaborative geographic information dialogues in spatial decision-making contexts. Collaboration requires representation and reasoning on a team mental model, which must be constructed from dialogue contexts and shared knowledge. An implementation of an intelligent, multimodal, multi-user geographic information environment, called GCCM_Connect, is presented as a proof-of-concept for the proposed architecture.