Tech Reports in Computer Science and Engineering

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1991 Human-Computer Interaction Laboratory Video Reports
(2000-06-23) Plaisant, Catherine (Editor)
Introduction - Ben Shneiderman, Scheduling home control devices - Catherine Plaisant, Ben Shneiderman, Touchscreen toggles - Catherine Plaisant , A home automation system - Reuel Launey (Custom Command Systems), PlayPen II (now known as PenPlay II) : A novel fingerpainting program - Andrew Sears, Ben Shneiderman, Touchscreen keyboards - Andrew Sears, Ben Shneiderman, Pie menus - Don Hopkins, Three interfaces for browsing tables of contents - Rick Chimera (Also cross-referenced as CAR-TR-791)
1992 Human-Computer Interaction Laboratory Video Reports
(1998-10-15) Plaisant, Catherine (Editor)
Introduction - Ben Shneiderman, [3:00], Dynamic Queries: database searching by direct manipulation - Ben Shneiderman, Chris Williamson, Christopher Ahlberg, [10:55], Treemaps for visualizing hierarchical information - Ben Shneiderman, Brian Johnson, Dave Turo, [11:25], Three strategies for directory browsing - Rick Chimera, [10:30], Filter-Flow metaphor for boolean queries - Degi Young, Ben Shneiderman, [6:35], The AT&T Teaching Theater: active learning through computer supported collaborative courseware - Kent Norman, [8:25], ACCESS: an online public access catalog at the Library of Congress - Gary Marchionini, [8:15] Remote Direct Manipulation: a telepathology workstation - Catherine Plaisant, Dave Carr, [7:30], Guiding automation with pixels: a technique for programming in the user interface - Richard Potter, [11:50] (Also cross-referenced as CAR-TR-792)
1993 Human-Computer Interaction Laboratory Video Reports
(1998-10-15) Plaisant, Catherine (Editor)
Introduction and table of contents - Ben Shneiderman, [4:00] Dynamaps: dynamic queries on a health statistics atlas - Catherine Plaisant and Vinit Jain, [6:34], Hierarchical visualization with Treemaps: making sense of pro basketball data - Dave Turo, [10:47], TreeViz: file directory browsing - Brian Johnson, [10:04], HyperCourseware: computer integrated tools in the AT&T Teaching Theater - Kent Norman, [7:08], Improving access to medical abstracts: Grateful Med Interface prototype - Gary Marchionini, [6:08], Layout appropriateness: guiding interface desi gn with simple task descriptions - Andrew Sears, [4:00] (Also cross-referenced as CAR-TR-793)
1994 Human-Computer Interaction Laboratory Video Reports
(1998-10-15) Plaisant, Catherine (Edited by); Reesch, John (Video by)
80 minute video demonstrations of the past year's research Topics are: Introduction and table of contents - Ben Shneiderman, [3:18] Visual information seeking using the FilmFinder - Christopher Ahlberg, Ben Shneiderman, [6:12] Organization overviews and role management-Inspiration for future desktop environments - Catherine Plaisant, Ben Shneiderman, [9:39] Visual decision-making: using treemaps for the analytic hierarchy process - Toshiyuki Asahi, Ben Shneiderman, David Turo, [8:34] Visual information management for satellite network configuration-Catherine Plaisant, Harsha Kumar, Marko Teittinen, Ben Shneiderman, [8:49] Graphical macros: a technique for customizing any application using pixel-pattern matching-Richard Potter, [9:49] Education by engagement and construction: can distance learning be better than face to face?- Ben Shneiderman, [15:00] Dynamic queries demos: revised HomeFinder and text version plus health statistics atlas-Ben Shneiderman, [9:40] Dynamic Queries are user controlled displays of visual or textual information. Ben Shneiderman presents the HomeFinder (developed by Chris Williamson), followed by the text version (Vinit Jain) and the Health Statistics Atlas (Catherine Plaisant and Vinit Jain). CHI '94 slide and video show- [9:12]Open House '94 Video (Also cross-referenced as CAR-TR-794)
1995 Human-Computer Interaction Laboratory Video Reports
(2000-07-21) Plaisant, Catherine (Edited by)
49 minute video of the labs work over the past year. Topics are: Introduction and table of contents - Ben Shneiderman Using Dynamic Queries for Youth Services Information - Anne Rose, Ajit Vanniamparampil Life-Lines: Visualizing Personal Histories - Brett Milash, Catherine Plaisant, Anne Rose Dynamic Queries and Pruning for Large Tree Structures - Harsha Kumar Browsing Anatomical Image Databases : the Visible Human - Flip Korn, Chris North Spinning Your Web: WWW Interface Design Issues - Vince Boisselle BizView : Managing Business and Network Alarms - Catherine Plaisant, Wei Zhao and Rina Levy Animated Specifications Using Interaction Object Graphs - David Carr WinSurfer: Treemaps for Replacing the Windows File Manager - Marko Teittinen (Also cross-referenced as CAR-TR-795)
1996 HCIL Video Reports
(1998-12-05) Plaisant, Catherine
Elastic Windows for Rapid Multiple Window Management Life-Lines: Visualizing Personal Histories Designing Interfaces for Youth Services Information Management Query Previews in Networked Information Systems the Case of EOSDIS Baltimore Learning Communities Table of Contents of the 1995 HCIL Video Reports Table of Contents of the 1994 HCIL Video Reports Visual Information Seeking using the FilmFinder (Extract from the HCIL1994 Video Report
Accuracy, Target Reentry and Fitts' Law Performance of Preschool Children Using Mice
(2003-06-04) Hourcade, Juan Pablo; Bederson, Benjamin B.; Druin, Allison; Guimbretiere, Francois
Several experiments by psychologists and human factors researchers have shown that when young children execute pointing tasks, they perform at levels below older children and adults. However, these experiments were not conducted with the purpose of providing guidelines for the design of graphical user interfaces. To address this need, we conducted a study to gain a better understanding of 4 and 5 year-old children's use of mice. We compared the performance of thirteen 4 year-olds, thirteen 5 year-olds and thirteen young adults in point-and-click tasks. As expected, we found age had a significant effect on accuracy, target reentry and Fitts' law's index of performance. We also found that target size had a significant effect on accuracy and target reentry. Measuring movement time at four different times (first entering target, last entering target, pressing button, releasing button) yielded the result tha Fitts' law models children well only for the first time they enter the target. Another interesting result was that using the adjusted index of difficulty (IDe) in Fitts' law calculations yielded lower linear regression correlation coefficients than using the unadjusted index of difficulty (ID). These results provide valuable guidelines for the design of graphical user interfaces for young children, in particular when it comes to sizing visual targets. They also suggest designers should adopt strategies to accommodate users with varying levels of skill. (UMIACS-2003-42) (HCIL-2003-16)
Accurate Anchor-Free Node Localization in Wireless Sensor Networks
(2006-02-10T16:51:23Z) Youssef, Adel; Younis, Mohamed; Agrawala, Ashok
There has been a growing interest in the applications of wireless sensor networks in unattended environments. In such applications, sensor nodes are usually deployed randomly in an area of interest. Knowledge of accurate node location is essential in such network setups in order to correlate the reported data to the origin of the sensed phenomena. In addition, awareness of the nodes’ positions can enable employing efficient management strategies such as geographic routing and conducting important analysis such as node coverage properties. In this paper, we present an efficient anchor-free protocol for localization in wireless sensor networks. Each node discovers its neighbors that are within its transmission range and estimates their ranges. Our algorithm fuses local range measurements in order to form a network wide unified coordinate systems while minimizing the overhead incurred at the deployed sensors. Scalability is achieved through grouping sensors into clusters. Simulation results show that the proposed protocol achieves precise localization of sensors and maintains consistent error margins. In addition, we capture the effect of error accumulation of the node’s range estimates and network’s size and connectivity on the overall accuracy of the unified coordinate system.
Accurate computation of Galerkin double surface integrals in the 3-D boundary element method
(2015-05-29) Adelman, Ross; Gumerov, Nail A.; Duraiswami, Ramani
Many boundary element integral equation kernels are based on the Green’s functions of the Laplace and Helmholtz equations in three dimensions. These include, for example, the Laplace, Helmholtz, elasticity, Stokes, and Maxwell equations. Integral equation formulations lead to more compact, but dense linear systems. These dense systems are often solved iteratively via Krylov subspace methods, which may be accelerated via the fast multipole method. There are advantages to Galerkin formulations for such integral equations, as they treat problems associated with kernel singularity, and lead to symmetric and better conditioned matrices. However, the Galerkin method requires each entry in the system matrix to be created via the computation of a double surface integral over one or more pairs of triangles. There are a number of semi-analytical methods to treat these integrals, which all have some issues, and are discussed in this paper. We present novel methods to compute all the integrals that arise in Galerkin formulations involving kernels based on the Laplace and Helmholtz Green’s functions to any specified accuracy. Integrals involving completely geometrically separated triangles are non-singular and are computed using a technique based on spherical harmonics and multipole expansions and translations, which results in the integration of polynomial functions over the triangles. Integrals involving cases where the triangles have common vertices, edges, or are coincident are treated via scaling and symmetry arguments, combined with automatic recursive geometric decomposition of the integrals. Example results are presented, and the developed software is available as open source.
An Accurate Time-Management Unit for Real-Time Processors
(1998-10-15) Kailas, Krishnan K.; Agrawala, Ashok K.
Time management is an important aspect of real-time computation. Traditional high performance processors provide little or no support for management of time. In this report, we propose a time-management unit which can greatly help improve the performance of a real-time system. The proposed unit can be added to any processor architecture without affecting its performance. We also explain how the unit helps to solve the clock synchronization problems in a real-time network. (Also cross-referenced as UMIACS-TR-97-28)
ACE: A Novel Software Platform to Ensure the Integrity of Long Term Archives
(2007-01-31) Song, Sangchul; JaJa, Joseph
We develop a new methodology to address the integrity of long term archives using rigorous cryptographic techniques. A prototype system called ACE (Auditing Control Environment) was designed and developed based on this methodology. ACE creates a small-size integrity token for each digital object and some cryptographic summary information based on all the objects handled within a dynamic time period. ACE continuously audits the contents of the various objects according to the policy set by the archive, and provides mechanisms for an independent third-party auditor to certify the integrity of any object. In fact, our approach will allow an independent auditor to verify the integrity of every version of an archived digital object as well as link the current version to the original form of the object when it was ingested into the archive. We show that ACE is very cost effective and scalable while making no assumptions about the archive architecture. We include in this paper some preliminary results on the validation and performance of ACE on a large image collection.
Active Harmony: Towards Automated Performance Tuning
(2002-08-01) Tapus, Cristian; Chung, I-Hsin; Hollingsworth, Jeffrey K.
In this paper we present the Active Harmony automated runtime tuning system. We describe the interface used by programs to make applications tunable. We present the Library Specification Layer which helps program library developers expose multiple variations of the same API using different algorithms. The Library Specification Language helps to select the most appropriate program library to tune the overall performance. We also present the optimization algorithm that we used to adjust parameters in the application and the libraries. Finally, we present results that show how the system is able to tune several real applications. The automated tuning system is able to tune the application parameters to within a few percent of the best value after evaluating only 11 configurations out of over 1,700 possible combinations. Also UMIACS-TR-2002-54
Active Logic and Heim's Rules for Updating Discourse Context
(1998-10-15) Gurney, John; Perlis, Don; Purang, Khemdut
Discourse unfolds in time, giving rise to a cascade of belief changes in the listener. Yet this temporal evolution of discourse and belief is typically ignored in theoretical treatments of discourse. It has been claimed (see Soames~\cite{soames:presuppositions}) that Heim's~\cite{heim:projection_problem} theory of discourse context accounts for non-implicative discourse updating. We will present a new non-implicative discourse that cannot be accounted for with Heim's use of global or local accommodation and which appears to require attention to \emph{evolution} of discourse. We use this example to motivate remaking Heim's update function, aimed toward a unified approach to discourse---one in which Heim's rules for discourse updating can account for more of the problem cases for the theory of discourse context. These rules and the revised update function can then serve as principles that constrain the building of representations for discourse context (such as the Discourse Representation Structures, of Discourse Representation Theory, ~\cite{kamp:reyle}). We propose \emph{active logic} as a convenient tool for executing the required inferences (as called for by our revised version of Heim's update function) as the discourse evolves through time. (Also cross-referenced as UMIACS-TR-96-43)
Active Logic Applied to Cancellation of Gricean Implicture
(1998-10-15) Purang, Khemdut; Perlis, Don; Gurney, John
Dialog proceeds over time, during which inferred beliefs come and go in the listener. Yet this temporal aspect of dialog and belief is typically ignored in theoretical treatments of dialog. Using a simple example of a dialog with an implicature that arises partway through and then is later retracted, we discuss how Gricean maxims and nonmonotonicity may relate to each other and to a computational treatment of implicature. In effect we seek to track reasoning along Gricean lines over time. We present our own computational approach to this, giving an implementation in the formalism of active logics. (Also cross-referenced as UMIACS-TR-96-42)
Active Logics: A Unified Formal Approach to Episodic Reasoning
(1999-10-14) Elgot-Drapkin, Jennifer; Kraus, Sarit; Miller, Michael; Nirkhe, Madhura; Perlis, Donald
Artificial intelligence research falls roughly into two categories: formal and implementational. This division is not completely firm: there are implementational studies based on (formal or informal) theories (e.g., CYC, SOAR, OSCAR), and there are theories framed with an eye toward implementability (e.g., predicate circumscription). Nevertheless, formal/theoretical work tends to focus on very narrow problems (and even on very special cases of very narrow problems) while trying to get them ``right'' in a very strict sense, while implementational work tends to aim at fairly broad ranges of behavior but often at the expense of any kind of overall conceptually unifying framework that informs understanding. It is sometimes urged that this gap is intrinsic to the topic: intelligence is not a unitary thing for which there will be a unifying theory, but rather a ``society'' of subintelligences whose overall behavior cannot be reduced to useful characterizing and predictive principles. Here we describe a formal architecture that is more closely tied to implementational constraints than is usual for formalisms, and which has been used to solve a number of commonsense problems in a unified manner. In particular, we address the issue of formal, integrated, and longitudinal reasoning: inferentially-modeled behavior that incorporates a fairly wide variety of types of commonsense reasoning within the context of a single extended episode of activity requiring keeping track of ongoing progress, and altering plans and beliefs accordingly. Instead of aiming at optimal solutions to isolated, well-specified and temporally narrow problems, we focus on satisficing solutions to under-specified and temporally-extended problems, much closer to real-world needs. We believe that such a focus is required for AI to arrive at truly intelligent mechanisms with the ability to behave effectively over considerably longer time periods and range of circumstances than is common in AI today. While this will surely lead to less elegant formalisms, it also surely is requisite if AI is to get fully out of the blocks-world and into the real world. (Also cross-referenced as UMIACS-TR-99-65)
Active Proxy-G: Optimizing the Query Execution Process in the Grid
(2002-05-22) Andrade, Henrique; Kurc, Tahsin; Sussman, Alan; Saltz, Joel
The Grid environment facilitates collaborative work and allows many users to query and process data over geographically dispersed data repositories. Over the past several years, there has been a growing interest in developing applications that interactively analyze datasets, potentially in a collaborative setting. We describe an Active Proxy-G service that is able to cache query results, use those results for answering new incoming queries, generate subqueries for the parts of a query that cannot be produced from the cache, and submit the subqueries for final processing at application servers that store the raw datasets. We present an experimental evaluation to illustrate the effects of various design tradeoffs. We also show the benefits that two real applications gain from using the middleware. (Also UMIACS-TR-2002-41)
AD (Attacker Defender) Game
(2002-01-31) Kochut, Andrzej; Agrawala, Ashok K.; Larsen, Ronald L.; Shankar, A. Udaya
Information Dynamics is a framework for agent-based systems that gives a central position to the role of information, time, and the value of information. We illustrate system design in the Information Dynamics Framework by developing an intelligence game called AD involving attackers, defenders and targets operating in some space of locations. The goal of the attackers is to destroy all targets. Target destruction takes place when the number of attackers in the target's neighborhood exceeds the number of defenders in this neighborhood by a value WINNING_DIFFERENCE. The goal of defenders is to prevent attackers from achieving their goal. (Also UMIACS-TR-2001-45)
Adapting Scrum to Managing a Research Group
(2010-09-18) Hicks, Michael; Foster, Jeffrey S.
Score is an adaptation of the Scrum agile software development methodology to the task of managing Ph.D. students in an academic research group. This paper describes Score, conceived in October 2006, and our experience using it. We have found that Score enables us---faculty and students---to be more efficient and thereby more productive, and enhances the cohesion of our research group.
Adapting to Route-demand and Mobility (ARM) in Ad hoc Network Routing
(2001-05-10) Ahn, Sungjoon; Shankar, A. Udaya
We present ARM (Adapting to Route-demand and Mobility), a control mechanism that allows any proactive routing protocol to dynamically adapt in a totally distributed manner to changes in node mobility and workload route-demands. Each node independently maintains a {\it mobility metric} indicating how fast its neighborhood is currently changing, and a {\it route-demand metric} indicating which destinations are currently involved in data forwarding. Control functions use these metrics to dynamically adjust the period and the content of routing updates. We apply ARM to the DSDV protocol, coming up with ARM-DSDV. For various mobility and workload scenarios, ARM-DSDV typically achieves the same data delivery as DSDV with update period optimized for the scenario, while saving up to 60\% in routing cost. Lower cost gives data traffic more available bandwidth. (Cross-referenced as UMIACS-TR-2001-08)
Adapting Treemaps to Stock Portfolio Visualization
(1998-10-15) Turo, David; Jungmeister, Walter-Alexander
Treemap visualization techniques are extended and applied to stock market portfolios via a prototype application. Designed to facilitate financial decision-making, the prototype provides an overview of large amounts of hierarchical financial data and allows users to alter aspects of the visual display dynamically. Treemap concepts are illustrated via examples which address common portfolio management needs. (Also cross-referenced as CAR-TR-648) (Also cross-referenced as SRC-TR-92-120)