An Empirical Evaluation of the System Usability Scale

This article presents nearly 10 year's worth of System Usability Scale (SUS) data collected on numerous products in all phases of the development lifecycle. The SUS, developed by Brooke (1996) Brooke, J. 1996. “SUS: A “quick and dirty” usability scale”. In Usability evaluation in industry, Edited by: Jordan, P. W., Thomas, B. A. Weerdmeester and McClelland, I. L. 189–194. London: Taylor & Francis.  [Google Scholar], reflected a strong need in the usability community for a tool that could quickly and easily collect a user's subjective rating of a product's usability. The data in this study indicate that the SUS fulfills that need. Results from the analysis of this large number of SUS scores show that the SUS is a highly robust and versatile tool for usability professionals. The article presents these results and discusses their implications, describes nontraditional uses of the SUS, explains a proposed modification to the SUS to provide an adjective rating that correlates with a given score, and provides details of what constitutes an acceptable SUS score.     

Action selection and task sequence learning for hybrid dynamical cognitive agents

As a foundation for action selection and task-sequencing intelligence, the reactive and deliberative subsystems of a hybrid agent can be unified by a single, shared representation of intention. In this paper, we summarize a framework for hybrid dynamical cognitive agents (HDCAs) that incorporates a representation of dynamical intention into both reactive and deliberative structures of a hybrid dynamical system model, and we present methods for learning in these intention-guided agents. The HDCA framework is based on ideas from spreading activation models and belief–desire–intention (BDI) models. Intentions and other cognitive elements are represented as interconnected, continuously varying quantities, employed by both reactive and deliberative processes. HDCA learning methods—such as Hebbian strengthening of links between co-active elements, and belief–intention learning of task-specific relationships—modify interconnections among cognitive elements, extending the benefits of reactive intelligence by enhancing high-level task sequencing without additional reliance on or modification of deliberation. We also present demonstrations of simulated robots that learned geographic and domain-specific task relationships in an office environment.     

Closed-loop drip irrigation control using a hybrid wireless sensor and actuator network

In this research, a closed-loop drip irrigation control hybrid wireless sensor and actuator network (HWSAN) prototype were developed and deployed in a crop field for soil property precise measurement and precision irrigation in accordance with the measured soil property. The HWSAN was composed of a wireless sensor and actuator network (WSAN) used for in-field soil property monitoring and irrigation control and a laboratory supervising system. The WSAN included ten sensor nodes, five irrigation control nodes...     

Cerebral: visualizing multiple experimental conditions on a graph with biological context

Systems biologists use interaction graphs to model the behavior of biological systems at the molecular level. In an iterative process, such biologists obser ve the reactions of living cells under various experimental conditions, view the results in the context of the interaction graph, and then propose changes to the graph model. These graphs ser ve as a form of dynamic knowledge representation of the biological system being studied and evolve as new insight is gained from the experimental data. While numerous graph layout and drawing packages are available, these tools did not fully meet the needs of our immunologist collaborators. In this paper, we describe the data information display needs of these immunologists and translate them into design decisions. These decisions led us to create Cerebral, a system that uses a biologically guided graph layout and incor porates experimental data directly into the graph display. Small multiple views of different experimental conditions and a data-driven parallel coordinates view enable correlations between experimental conditions to be analyzed at the same time that the data is viewed in the graph context. This combination of coordinated views allows the biologist to view the data from many different perspectives simultaneously. To illustrate the typical analysis tasks performed, we analyze two datasets using Cerebral. Based on feedback from our collaboratorsweconcludethat Cerebral is a valuable tool for analyzing experimental data in the context of an interaction graph model.      

The structure of boron in boron fibres

The structure of noncrystalline, chemically vapour-deposited boron fibres was investigated by computer modelling the experimentally obtained X-ray diffraction patterns. The diffraction patterns from the models were computed using the Debye scattering equation. The modelling was done utilizing the minimum nearest-neighbour distance, the density of the model, and the broadening and relative intensity of the various peaks as boundary conditions. The results suggest that the fibres consist of a continuous network of randomly oriented regions of local atomic order, about 2 nm in diameter, containing boron atoms arranged in icosahedra. Approximately half of these regions have a tetragonal structure and the remaining half a distorted rhombohedral structure. The model also indicates the presence of many partial icosahedra and loose atoms not associated with any icosahedra. The partial icosahedra and loose atoms indicated in the present model are in agreement with the relaxing sub-units which have been suggested to explain the anelastic behaviour of fibre boron and the loosely bound boron atoms which have been postulated to explain the strengthening mechanism in boron fibres during thermal treatment.     

TRACE qualification via analysis of the EIR gas-loop experiments with smooth rods

Several gas-loop experimental programs were carried out during the 1970–1980s at the Eidgenössisches Institut für Reaktorforschung (EIR, now PSI), Switzerland. In the present work, a wide range of thermal–hydraulics tests for smooth rods, which form part of the experiments conducted at the time, have been reanalyzed with the aim of qualifying the TRACE code. The latter constitutes the thermal–hydraulics module of PSI’s FAST code system, currently being applied to the multi-physics analysis of advanced fast reactor systems, including the Generation IV Gas-Cooled Fast Reactor (GFR). It is shown, from the present analysis, that the built-in TRACE heat transfer and friction correlations are indeed quite suitable for gas cooling under prototypic GFR conditions.     

Lack of clinical utility of bronchoalveolar lavage cultures for cytomegalovirus in HIV infection

This study assessed the presence of cytomegalovirus (CMV) in bronchoalveolar lavage (BAL) in three subpopulations of HIV-infected patients and correlated its presence with clinical status during 3 mo of follow-up. Nineteen asymptomatic volunteers, six patients with CMV retinitis, and 46 patients with acute pulmonary symptoms underwent BAL and were assessed for CMV by cytopathology, conventional shell vial cultures, and antigen detection. Transbronchial biopsies were also obtained when possible and evaluated for histopathologic changes of CMV. All patients were followed for approximately 3 mo. Cytomegalovirus was detected in BAL in nine of 19 (47%) asymptomatic volunteers, in all six patients with CMV retinitis, and in 33 of 46 (72%) patients with pulmonary symptoms. Only one symptomatic patient with a positive CMV BAL culture developed clinically significant CMV pulmonary disease; this patient developed disseminated CMV and died. The only other death occurred in a patient with CMV retinitis who developed staphylococcal bacteremia. None of the asymptomatic volunteers or patients with CMV retinitis developed evidence of CMV pneumonia or any other organ disease with CMV. Cytomegalovirus is frequently detected in BAL from HIV-infected patients regardless of their pulmonary symptoms and its presence does not clinically predict significant pulmonary morbidity or mortality in 3 mo of follow-up.     

An open trial of integrative therapy for generalized anxiety disorder.

Cognitive-behavioral therapy (CBT), although effective, has the lowest average effect size for generalized anxiety disorder (GAD), when compared to effect sizes of CBT for other anxiety disorders. Additional basic and applied research suggests that although interpersonal processes and emotional avoidance may be maintaining GAD symptomatology, CBT has not sufficiently addressed interpersonal issues or emotion avoidance. This study aimed to test the feasibility and preliminary efficacy of an integrative psychotherapy, combining CBT with techniques to address interpersonal problems and emotional avoidance. Eighteen participants received 14 sessions of CBT plus interpersonal emotional processing therapy and three participants (for training and feasibility purposes) received 14 sessions of CBT plus supportive listening. Results showed that the integrative therapy significantly decreased GAD symptomatology, with maintenance of gains up to 1 year following treatment. In addition, comparisons with extant literature suggested that the effect size for this new GAD treatment was higher than the average effect size of CBT for GAD. Results also showed clinically significant change in GAD symptomatology and interpersonal problems with continued gains during the 1-year follow-up. Implications of these results are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A preliminary classification system for homeless veterans with mental illness.

The purpose of this study was that of defining psychiatric profiles among veterans based on a structured interview of 3,595 individuals administered by outreach mental health clinicians to individuals who were presently or recently homeless. The interview included ratings of presence or absence of current psychiatric disorders; alcoholism, drug abuse, psychosis, mood disorders, personality disorders, PTSD, and adjustment disorders. We identified three subgroups using cluster analysis each showing different diagnostic profiles that were characterized as "addiction" (n = 3,061), "psychosis" (n = 218), and "personality" disorders (n = 54). Cluster membership was related to demographic characteristics, living situation, length of homelessness, and symptoms and complaints including cognitive difficulties, suicidality, violence, and depression. Group comparison statistics were used to compare intercluster differences in demographics, homeless situation, symptoms, and subjective complaints. There were no major intercluster differences in socioethnic, demographic, and homeless situation variables. Differences occurred in complaints of depression, positive symptoms of psychosis, and suicidality. It was concluded that despite the disproportionate sizes of the clusters homeless veterans with mental illness are nevertheless heterogeneous with regard to their psychiatric profiles. (PsycINFO Database Record (c) 2010 APA, all rights reserved)