Browsing by Author "Kang, Hyunmo"

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    Combining Joins and Semijoins in Distributed Query Processing.
    (1987) Kang, Hyunmo; Roussopoulos, N.; ISR
    A new approach to distributed query processing is proposed. In the conventional approach, a query is processed by the reducing phase and the joining phase. In the reducing phase, the relations referenced in the query are reduced using semijoins, and all the relations are joined at the result site in the joining phase. In the proposed approach, an arbitrary interleaving of joins and semijoins is allowed toward the generation of the query result at the result site. The proposed approach considers the local processing cost as well as the data transmission cost while the conventional approach mostly considers the data transmission cost only. The effectiveness of the query processing strategies generated according to the proposed approach is discussed for both the restricted class of join queries and the general join queries.
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    Direct Annotation: A Drag-and-Drop Strategy for Labeling Photos (2000)
    (2005) Shneiderman, Ben; Kang, Hyunmo; ISR
    Annotating photos is such a time-consuming, tedious and error-prone data entry task that it discourages most owners of personal photo libraries. By allowing users to drag labels such as personal names from a scrolling list and drop them on a photo, we believe we can make the task faster, easier and more appealing. Since the names are entered in a database, searching for all photos of a friend or family member is dramatically simplified. We describe the user interface design and the database schema to support direct annotation, as implemented in our PhotoFinder prototype.
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    Dynamic Layout Management in a Multimedia Bulletin Board
    (2003-01-21) Kang, Hyunmo; Shneiderman, Ben; Wolff, Gregory J.
    This paper proposes a novel user interface to manage the dynamic layout of multimedia objects in the Multimedia Bulletin Board (MBB) system. The MBB has been designed and implemented as a prototype of an asynchronous communication system that enables rich communication and collaboration among users of multimedia objects such as text, image, moving picture, sound, voice, web, office document, and other files. The layout properties of the multimedia objects on a board (e.g. x-y position, size, z-order, partial occlusion, explicit and implicit links, etc.) show important and useful information on the user dynamics occurring within a board. However, a fixed layout created and edited by multiple users may prevent users from recognizing and identifying useful information. This paper resolves this problem with a novel user-controlled layout strategy made visible with dynamic layout templates (DLT). Users can reorganize the objects to extract meaningful information related to time, source, geographic location, or topic. (UMIACS-TR-2002-26) (HCIL-TR-2002-04)
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    Dynamic Layout Management in a Multimedia Bulletin Board (2002)
    (2005) Kang, Hyunmo; Shneiderman, Ben; Wolff, Gregory J; ISR
    This paper proposes a novel user interface to manage the dynamic layout of multimedia objects in the Multimedia Bulletin Board (MBB) system. The MBB has been designed and implemented as a prototype of an asynchronous communication system that enables rich communication and collaboration among users of multimedia objects such as text, image, moving picture, sound, voice, web, office document, and other files. The layout properties of the multimedia objects on a board (e.g. x-y position, size, z-order, partial occlusion, explicit and implicit links, etc.) show important and useful information on the user dynamics occurring within a board. However, a fixed layout created and edited by multiple users may prevent users from recognizing and identifying useful information. This paper resolves this problem with a novel user-controlled layout strategy made visible with dynamic layout templates (DLT). Users can reorganize the objects to extract meaningful information related to time, source, geographic location, or topic.
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    Exploring Personal Media: A Spatial Interface Supporting User-Defined Semantic Regions (2004)
    (2005) Kang, Hyunmo; Shneiderman, Ben; ISR
    Graphical mechanisms for spatially organizing personal media data could enable users to fruitfully apply their mental models. This paper introduces Semantic Regions, an innovative way for users to construct mental models by drawing regions on 2D space and specifying the semantics for each region. Then users can apply personal ontologies to personal media data using the fling-and-flock metaphor. This allows photos (or other personal media) to be dragged to the display and automatically grouped according to time, geography, family trees, groups of friends, or other conceptual maps. The prototype implementation for Semantic Regions, MediaFinder, was validated with two usability tests for usage and construction of user-defined mental models. Applications and extensions are discussed.
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    Immediate Usability: A Case Study of Public Access Design for a Community Photo Library (2003)
    (2005) Kules, Bill; Kang, Hyunmo; Plaisant, Catherine; Rose, Anne; Shneiderman, Ben; ISR
    This paper describes a novel instantiation of a digital photo library in a public access system. It demonstrates how designers can utilize characteristics of a target user community (social constraints, trust, and a lack of anonymity) to provide capabilities that would be impractical in other types of public access systems. It also presents a compact set of design principles and guidelines for ensuring the immediate usability of public access information systems. These principles and guidelines were derived from our experience developing PhotoFinder Kiosk, a community photo library. Attendees of a major HCI conference (CHI 2001 Conference on Human Factors in Computing Systems) successfully used the tool to browse and annotate collections of photographs spanning 20 years of HCI-related conferences, producing a richly annotated photo history of the field of human-computer interaction. Observations and log data were used to evaluate the tool and develop the guidelines. They provide specific guidance for practitioners, as well as a useful framework for additional research in public access interfaces.
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    Immediate Usability: Kiosk design principles from the CHI 2001 Photo Library
    (2003-01-21) Kules, Bill; Kang, Hyunmo; Plaisant, Catherine; Rose, Anne; Shneiderman, Ben
    This paper describes a novel set of design principles and guidelines for ensuring the immediate usability of public access systems. These principles and guidelines were formulated while developing PhotoFinder Kiosk, a community photo library. Attendees of CHI 2001 successfully used the tool to browse and annotate collections of photographs spanning 20 years of CHI and related conferences, producing a richly annotated photo history of the field of human-computer interaction. We used observations and log data to evaluate the tool and refine the guidelines. They provide specific guidance for practitioners, as well as a useful framework for additional research in public access interfaces. Keywords Photo collection, community photo library, group annotation, public access system, direct annotation, direct manipulation, drag-and-drop, immediate usability, zero-trial learning, walk-up-and-use, casual use. (UMIACS-TR-2001-71) (HCIL-TR-2001-23)
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    Immediate Usability: Kiosk design principles from the CHI 2001 Photo Library (2001)
    (2005) Kules, Bill; Kang, Hyunmo; Plaisant, Catherine; Rose, Anne; Shneiderman, Ben; ISR
    This paper describes a novel set of design principles and guidelines for ensuring the immediate usability of public access systems. These principles and guidelines were formulated while developing PhotoFinder Kiosk, a community photo library. Attendees of CHI 2001 successfully used the tool to browse and annotate collections of photographs spanning 20 years of CHI and related conferences, producing a richly annotated photo history of the field of human-computer interaction. We used observations and log data to evaluate the tool and refine the guidelines. They provide specific guidance for practitioners, as well as a useful framework for additional research in public access interfaces.
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    MANAGING AND EXPLORING MEDIA USING SEMANTIC REGIONS: A SPATIAL INTERFACE SUPPORTING USER-DEFINED MENTAL MODELS
    (2003-12-05) Kang, Hyunmo; Shneiderman, Ben; Computer Science
    Computer users deal with large numbers of personal media objects such as images, audio clips, voice mails, video clips, web pages, emails, and various document files. Users often struggle to interpret, explore, arrange, and use personal media objects because of three major problems; an ever increasing amount of personal media data, rigid organizing metaphor, and difficulty in rapid data access. With the progress of computer hardware and digitization technologies at the rate of Moore's law, users may generate, acquire, and store more and more personal media data on their personal machines. However, the means available for users to organize and customize their personal media information spaces are extremely poor and driven mostly by storage and distribution models, not users' needs. Furthermore, this rigid and system-oriented metaphor causes wide and deep file folder hierarchies and often forbids users to rapid data access from storage. This dissertation uses a graphical mechanism for spatially organizing personal media data based on users' mental models and introduces an innovative interaction metaphor to apply users' mental models to personal media data. Semantic Regions introduces an innovative way to construct users' mental models by drawing regions on 2D space and specifying the semantics for each region so that users can apply various personal ontologies to personal media data using the fling-and-flock metaphor. The prototype application, MediaFinder, validates the usability of the interface, particularly in comparison with alternative approaches. Contributions of this dissertation include: - Semantic Regions provides a formal model of spatial and dynamic reorganization of personal media data based on users' mental models. It extends the concept from a system-oriented file management system to a user-oriented personal media management system by employing the semantics of personal media data. - The MediaFinder personal media management tool, which uses Semantic Regions, the fling-and-flock metaphor, and flexible categorization capabilities to explore and manage personal media data sets. MediaFinder's object-oriented architecture can easily be extended to support variants of the Semantic Regions model. - The design and implementation of interaction models that support the personal media management tasks such as organization, meaning extraction, navigation, search, indexing, and navigation. - Two usability studies provided preliminary insight into the utility of Semantic Regions and led to design improvements for the construction and operation of Semantic Regions. - A framework for extending the Semantic Regions model, including the descriptions of possible extensions.
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    MediaFinder: An Interface for Dynamic Personal Media Management with Semantic Regions (2003)
    (2005) Kang, Hyunmo; Shneiderman, Ben; ISR
    Computer users deal with large amounts of personal media often face problems in managing and exploring it. This paper presents Semantic Regions, rectangular regions that enable users to specify their semantics or mental models, and the MediaFinder application, which uses Semantic Regions as the basis of a personal media management tool.
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    New Approaches to Help Users Get Started with Visual Interfaces: Multi-Layered Interfaces and Integrated Initial Guidance
    (2003-06-04) Kang, Hyunmo; Plaisant, Catherine; Shneiderman, Ben
    We are investigating new ways to help users learn to use public access interactive tools, in particular for the visual exploration of government statistics. Our work led to a series of interfaces using multi-layered design and a new help method called Integrated Initial Guidance. Multi-layer designs structure an interface so that a simpler interface is available for users to get started and more complex features are accessed as users move through the more advanced layers. Integrated Initial Guidance provides help within the working interface, right at the start of the application. Using the metaphor of ^sticky notes^ overlaid on top of the functional interface locates the main widgets, demonstrates their manipulation, and explains the resulting actions using preset animation of the interface. Additional sticky notes lead to example tasks, also being executed step by step within the interface itself. Usability testing with 12 participants led to refined designs and guidelines for the design of Integrated Initial Guidance interfaces. (UMIACS-TR-2003-36) (HCIL-2003-10)
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    New Approaches to Help Users Get Started with Visual Interfaces: Multi-Layered Interfaces and Integrated Initial Guidance (2003)
    (2005) Kang, Hyunmo; Plaisant, Catherine; Shneiderman, Ben; ISR
    We are investigating new ways to help users learn to use public access interactive tools, in particular for the visual exploration of government statistics. Our work led to a series of interfaces using multi-layered design and a new help method called Integrated Initial Guidance. Multi-layer designs structure an interface so that a simpler interface is available for users to get started and more complex features are accessed as users move through the more advanced layers. Integrated Initial Guidance provides help within the working interface, right at the start of the application. Using the metaphor of ticky notes overlaid on top of the functional interface locates the main widgets, demonstrates their manipulation, and explains the resulting actions using preset animation of the interface. Additional sticky notes lead to example tasks, also being executed step by step within the interface itself. Usability testing with 12 participants led to refined designs and guidelines for the design of Integrated Initial Guidance interfaces.
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    On Cost-effectiveness of a Semijoin in Distributed Query Processing.
    (1987) Kang, Hyunmo; Roussopoulos, N.; ISR
    The cost-effective reduction of relations by semijoins is the basis of the heuristic approach to distributed query processing. The cost-effectiveness of a semijoin was simply determined in the literature assuming that the local processing cost is negligible compared to the data transmission cost in distributed query processing. However, recently questions have been raised about the validity of the assumption, and some experimental works revealed that the local processing cost is also significant in distributed query processing. In this paper, we are concerned with the cost-effectiveness of a semijoin considering the local processing cost as well as the data transmission cost. To measure the effectiveness of a semijoin in terms of the local processing cost, we introduce the join sequence in which the relations are joined at the result site to answer the query. A dynamic programming algorithm is developed to generate the optimal join sequence for a given query. A simple heuristic algorithm is also developed to generate a join sequence for a given query.
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    On Propagation of Reduction Effects of a Semijoin in Distributed Query Processing.
    (1986) Kang, Hyunmo; Roussopoulos, N.; ISR
    In distributed query processing, the semijoin is used as an effective operator in reducing relations referenced in the query and thus reducing the total amount of data transmission. A semijoin is associated with two quantities: cost and benefit. These two quantities of semijoins are the useful ingredients in many heuristic algorithms proposed to generate a semijoin program which is a sequence of semijoins and is executed as a query pre- processing strategy. In this paper, in addition to the cost and benefit, we associate a semijoin with the third quantity: reduction propagation. It measures the propagation of reduction effects of a semijoin to other semijoins. We define this propagation in the context of distributed query processing and by precisely quantifying it, we present a heuristic algorithm to generate a semijoin program. The simulation reaults show that the new algorithm provides a considerable improvement over those based only on the cost and benefit.
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    Using 2-way Semijoins in Distributed Query Processing.
    (1987) Kang, Hyunmo; Roussopoulos, N.; ISR
    In distributed query processing, the semijoin has been used as an effective operator in reducing relations referenced in the query to reduce the total amount of data transmission. In this paper, we propose a new relational algebra operator, 2-way semijoin, which is an extended version of the semijoin, for more cost- effective distributed query processing. The 2-way semijoin is compared to the semijoin in terms of the reduction power and the propagation of reduction effects. We show that the 2-way semijoin has more reduction power than the semijoin and that the propagation of reduction effects by the 2-way semijoin is further than by the semijoin.
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    Visualization Methods for Personal Photo Collections: Browsing and Searching in the PhotoFinder (2000)
    (2005) Kang, Hyunmo; Shneiderman, Ben; ISR
    Software tools for personal photo collection management are proliferating, but they usually have limited searching and browsing functions. We implemented the PhotoFinder prototype to enable non-technical users of personal photo collections to search and browse easily. PhotoFinder provides a set of visual Boolean query interfaces, coupled with dynamic query and query preview features. It gives users powerful search capabilities. Using a scatter plot thumbnail display and drag-and-drop interface, PhotoFinder is designed to be easy to use for searching and browsing photos.