Differences in user-centeredness in a large R&D organization

Many organizations employ formal methodologies for developing systems and software. Formal methodologies help ensure that systems meet requirements, increase the predictability of outcomes, help manage complexity, and reduce risk. Expertise and certification in prominent methods can also serve promotional purposes for the organization. Despite these benefits, there appears to be much less methodological standardization in how organizations engage in user-centered activities, such as user interface design and usability testing. This study examines this issue in a single large research and development organization that emphasizes formal methodology in its software development. The study examined why different projects within the organization engaged in different amounts and types of user-centered activities. We interviewed system engineers and human factors engineers involved with four different system development projects. We developed case studies for each project and identified several trends. First, user-centered activities are sometimes seen as being more expendable than other parts of the development process and therefore are more likely to be cut when delays or cost overruns occur. Second, when the formal methodology did not specifically include steps for user-centered design or usability testing, it was difficult for engineers to incorporate such activities because there was nowhere to put them due to resource constraints. Finally, several participants reported that their projects included user-centered activities mainly because the system engineers had first been exposed to human factors on earlier projects

Experimental study of digital image processing techniques for LANDSAT data

The author has identified the following significant results. Results are reported for: (1) subscene registration, (2) full scene rectification and registration, (3) resampling techniques, (4) and ground control point (GCP) extraction. Subscenes (354 pixels x 234 lines) were registered to approximately 1/4 pixel accuracy and evaluated by change detection imagery for three cases: (1) bulk data registration, (2) precision correction of a reference subscene using GCP data, and (3) independently precision processed subscenes. Full scene rectification and registration results were evaluated by using a correlation technique to measure registration errors of 0.3 pixel rms thoughout the full scene. Resampling evaluations of nearest neighbor and TRW cubic convolution processed data included change detection imagery and feature classification. Resampled data were also evaluated for an MSS scene containing specular solar reflections

Adapting the cognitive walkthrough method to assess the usability of a knowledge domain visualization

The usability of knowledge domain visualization (KDViz) tools can be assessed at several levels. Cognitive Walkthrough (CW) is a well-known usability inspection method that focuses on how easily users can learn software through exploration. Typical applications of CW follow structured tasks where user goals and action sequences that lead to achievement of the goals are well-defined. KDViz and other information visualization tools, however, are typically designed for users to explore data and user goals and actions are less well understood. In this paper, we describe how the traditional CW method may be adapted for assessing the usability of these systems. We apply the adapted version of CW to CiteSpace, a KDViz tool that uses bibliometric analyses to create visualizations of scientific literatures. We describe usability issues identified by the adapted CW and discuss how CiteSpace supported the completion of tasks, such as identifying research fronts, and the achievement of goals. Finally, we discuss improvements to the adapted CW and issues to be addressed before applying it to a wider range of KDViz tools

Complex actions in two-dimensional topology change

We investigate topology change in (1+1) dimensions by analyzing the scalar-curvature action $1/2 \int R dV$ at the points of metric-degeneration that (with minor exceptions) any nontrivial Lorentzian cobordism necessarily possesses. In two dimensions any cobordism can be built up as a combination of only two elementary types, the ``yarmulke'' and the ``trousers.'' For each of these elementary cobordisms, we consider a family of Morse-theory inspired Lorentzian metrics that vanish smoothly at a single point, resulting in a conical-type singularity there. In the yarmulke case, the distinguished point is analogous to a cosmological initial (or final) singularity, with the spacetime as a whole being obtained from one causal region of Misner space by adjoining a single point. In the trousers case, the distinguished point is a ``crotch singularity'' that signals a change in the spacetime topology (this being also the fundamental vertex of string theory, if one makes that interpretation). We regularize the metrics by adding a small imaginary part whose sign is fixed to be positive by the condition that it lead to a convergent scalar field path integral on the regularized spacetime. As the regulator is removed, the scalar density $1/2 \sqrt{-g} R$ approaches a delta-function whose strength is complex: for the yarmulke family the strength is $\beta -2\pi i$, where $\beta$ is the rapidity parameter of the associated Misner space; for the trousers family it is simply $+2\pi i$. This implies that in the path integral over spacetime metrics for Einstein gravity in three or more spacetime dimensions, topology change via a crotch singularity is exponentially suppressed, whereas appearance or disappearance of a universe via a yarmulke singularity is exponentially enhanced.Comment: 34 pages, REVTeX v3.0. (Presentational reorganization; core results unchanged.

Thermodynamics of (3+1)-dimensional black holes with toroidal or higher genus horizons

We examine counterparts of the Reissner-Nordstrom-anti-de Sitter black hole spacetimes in which the two-sphere has been replaced by a surface Sigma of constant negative or zero curvature. When horizons exist, the spacetimes are black holes with an asymptotically locally anti-de Sitter infinity, but the infinity topology differs from that in the asymptotically Minkowski case, and the horizon topology is not S^2. Maximal analytic extensions of the solutions are given. The local Hawking temperature is found. When Sigma is closed, we derive the first law of thermodynamics using a Brown-York type quasilocal energy at a finite boundary, and we identify the entropy as one quarter of the horizon area, independent of the horizon topology. The heat capacities with constant charge and constant electrostatic potential are shown to be positive definite. With the boundary pushed to infinity, we consider thermodynamical ensembles that fix the renormalized temperature and either the charge or the electrostatic potential at infinity. Both ensembles turn out to be thermodynamically stable, and dominated by a unique classical solution.Comment: 25 pages, REVTeX v3.1, contains 5 LaTeX figures. (Typos corrected, references and minor comments added. To be published in Phys. Rev. D.

Air Traffic Control System Baseline Methodology Guide

The Air Traffic Control System Baseline Methodology Guide serves as a reference in the design and conduct of baseline studies. Engineering research psychologists are the intended audience for the Methodology Guide, which focuses primarily on techniques for studying the interaction between ATC systems and the controllers who use them. The Methodology Guide provides the following information: (a) descriptions of and references to past baselines that have successfully used the methodology, (b) detailed descriptions of the baseline operational constructs and corresponding objective and subjective measures, (c) a description of the overall baseline methodology, (d) other recommendations and lessons learned regarding the successful conduct of system baselines, and (e) a discussion of the role of system baselines in the ATC system acquisition process

Lewis X antigen mediates adhesion of human breast carcinoma cells to activated endothelium. Possible involvement of the endothelial scavenger receptor C-Type lectin

Lewis x (Lex, CD15), also known as SSEA-1 (stage specific embryonic antigen-1), is a trisaccharide with the structure Galβ(1–4)Fucα(1–3)GlcNAc, which is expressed on glycoconjugates in human polymorphonuclear granulocytes and various tumors such as colon and breast carcinoma. We have investigated the role of Lex in the adhesion of MCF-7 human breast cancer cells and PMN to human umbilical endothelial cells (HUVEC) and the effects of two different anti-Lex mAbs (FC-2.15 and MCS-1) on this adhesion. We also analyzed the cytolysis of Lex+-cells induced by anti-Lex mAbs and complement when cells were adhered to the endothelium, and the effect of these antibodies on HUVEC. The results indicate that MCF-7 cells can bind to HUVEC, and that MCS-1 but not FC-2.15 mAb inhibit this interaction. Both mAbs can efficiently lyse MCF-7 cells bound to HUVEC in the presence of complement without damaging endothelial cells. We also found a Lex-dependent PMN interaction with HUVEC. Although both anti-Lex mAbs lysed PMN in suspension and adhered to HUVEC, PMN aggregation was only induced by mAb FC-2.15. Blotting studies revealed that the endothelial scavenger receptor C-type lectin (SRCL), which binds Lex-trisaccharide, interacts with specific glycoproteins of Mr␣∼␣28 kD and 10 kD from MCF-7 cells. The interaction between Lex+-cancer cells and vascular endothelium is a potential target for cancer treatment.Fil: Elola, Maria Teresa. Fundación Instituto Leloir; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Capurro, Mariana Isabel. University of Toronto; CanadáFil: Barrio, Maria Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Investigación, Docencia y Prevención del Cáncer; ArgentinaFil: Coombs, Peter J.. Imperial College London; Reino UnidoFil: Taylor, Maureen E.. Imperial College London; Reino UnidoFil: Drickamer, Kurt. Imperial College London; Reino UnidoFil: Mordoh, Jose. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Investigación, Docencia y Prevención del Cáncer; Argentin

Human Factors Considerations for Passwords and Other User Identification Techniques Part 2: Field Study, Results and Analysis

Within the Federal Aviation Administration (FAA) Air Traffic Organization (ATO), Technical Operations (TO) personnel ensure that the systems that make up the National Airspace System (NAS) function safely and effectively. TO personnel manage and maintain more than 44,000 pieces of NAS equipment and systems at over 6,000 facilities and locations. They work at many types of facilities including the National Operations Control Center (NOCC), Operations Control Centers (OCCs), Air Route Traffic Control Centers (ARTCCs), Terminal Radar Approach Control (TRACON) facilities, Air Traffic Control Towers (ATCTs), and Automated Flight Service Stations (AFSSs). The FAA employs a variety of user-identification techniques including knowledge-based techniques, such as passwords, token-based techniques (such as badge readers) to ensure that facilities, equipment, and personnel are secure. In 2004, the Technical Operations Services organization became increasingly concerned about the number of usernames, passwords, and tokens that TO personnel were being expected to use. The NAS Human Factors Group conducted a field study to examine the human factors implications of user-identification techniques currently employed at field sites to prevent unauthorized access to NAS equipment and information technology systems. In this report, we present findings from the field study and provide recommendations that are specific to the TO users, tasks, and environment. These recommendations seek to improve the human factors of user-identification technologies and policies to improve the productivity, workload, and job satisfaction of TO employees

Conference Control System Computer-Human Interface Prototype Description and Design

The Federal Aviation Administration (FAA) Air Traffic Control System Command Center (ATCSCC) is responsible for the strategic aspects of the National Airspace System (NAS). The ATCSCC modifies traffic flow and rates when congestion, weather, equipment outages, runway closures, or other operational conditions affect the NAS. Controllers at the ATCSCC accomplish these tasks by communicating with NAS stakeholders like local FAA facilities, airlines, and other national civil aviation authorities. In 2004, the FAA deployed the Conference Control System (CCS) as part of infrastructure modernization to meet increased capacity demands. The CCS provides many new functions and a computer-human interface (CHI) based on touch-entry display (TED) technology. The NAS Human Factors Group conducted a user-centered design project to explore the CCS CHI requirements. In collaboration with the CCS User Team, we developed mouse- and TED-based CHI prototypes to demonstrate the potential CCS functionality. This report discusses the approach we took in designing the CCS prototype and the rationale for each of the important CHI elements. Many of the concepts developed in the prototype were implemented into the operational CCS. The report also discusses the role of iterative prototyping in increasing designers\u2019 and users\u2019 understanding of the tasks, requirements, and CHI development process. Future programs can use the design rationale to guide the creation of CHIs for new telecommunication systems. We believe that the design approach adopted in this project allowed for a better elicitation of the user requirements and helped educate the user team regarding human factors and usability issues