2,742 research outputs found
User Interface Management Systems: A Survey and a Proposed Design
The growth of interactive computing has resulted in increasingly more complex styles of interaction between user and computer. To facilitate the creation of highly interactive systems, the concept of the User Interface Management System (UIMS) has been developed. Following the definition of the term 'UIMS' and a consideration of the putative advantages of the UIMS approach, a number of User Interface Management Systems are examined. This examination focuses in turn on the run-time execution system, the specification notation and the design environment, with a view to establishing the features which an "ideal" UIMS should possess. On the basis of this examination, a proposal for the design of a new UIMS is presented, and progress reported towards the implementation of a prototype based on this design
A mean-removed variation of weighted universal vector quantization for image coding
Weighted universal vector quantization uses traditional codeword design techniques to design locally optimal multi-codebook systems. Application of this technique to a sequence of medical images produces a 10.3 dB improvement over standard full search vector quantization followed by entropy coding at the cost of increased complexity. In this proposed variation each codebook in the system is given a mean or 'prediction' value which is subtracted from all supervectors that map to the given codebook. The chosen codebook's codewords are then used to encode the resulting residuals. Application of the mean-removed system to the medical data set achieves up to 0.5 dB improvement at no rate expense
Temporal Aspects of Tasks in the User Action Notation
The need for communication among a multiplicity of cooperating roles in user interface development translates into the need for a common set of interface design representation techniques. The important difference between design of the interaction part of the interface and design of the interface software calls for representation techniques with a behavioral view---a view that focuses on user interaction rather than on the software. The User Action Notation (UAN) is a user- and task-oriented notation that describes physical (and other) behavior of the user and interface as they perform a task together. The primary abstraction of the UAN is a user task. The work reported here addresses the need to identify temporal relationships within user task descriptions and to express explicitly and precisely how designers view temporal relationships among those tasks. Drawing on simple temporal concepts such as events in time and preceding and overlapping of time intervals, we identify basic temporal relationships among tasks: sequence, waiting, repeated disjunction, order independence, interruptibility, one-way interleavability, mutual interleavability, and concurrency. The UAN temporal relations, through the notion of modal logic, offer an explicit and precise representation of the specific kinds of temporal behavior that can occur in asynchronous user interaction, without the need to detail all cases that might result
Formality and informality in the summative assessment of motor vehicle apprentices: a case study
This article explores the interaction of formal and informal attributes of competence‐based assessment. Specifically, it presents evidence from a small qualitative case study of summative assessment practices for competence‐based qualifications within apprenticeships in the motor industry in England. The data are analysed through applying an adaptation of a framework for exploring the interplay of formality and informality in learning. This analysis reveals informal mentoring as a significant element which influences not only the process of assessment, but also its outcomes. We offer different possible interpretations of the data and their analysis, and conclude that, whichever interpretation is adopted, there appears to be a need for greater capacity‐building for assessors at a local level. This could acknowledge a more holistic role for assessors; recognise the importance of assessors’ informal practices in the formal retention and achievement of apprentices; and enhance awareness of inequalities that may be reinforced by both informal and formal attributes of assessment practices
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Fractionating negative and positive affectivity in handedness: Insights from the Reinforcement Sensitivity Theory of personality
The Annett Hand Preference Questionnaire (AHPQ), as modified by Briggs and Nebes [(1975). Patterns of hand preference in a student population. Cortex, 11(3), 230-238. doi: 10.1016/s0010-9452(75)80005-0 ], was administered to a sample of 177 participants alongside the Reinforcement Sensitivity Theory of Personality Questionnaire [RST-PQ; Corr, P. J., & Cooper, A. (2016). The Reinforcement Sensitivity Theory of Personality Questionnaire (RST-PQ): Development and validation. Psychological Assessment. doi: 10.1037/pas000 ], which measures two factors of defensive negative emotion, motivation and affectivity-the Behavioural Inhibition System (BIS) and the Fight-Flight-Freeze System (FFFS)-and one positive-approach dimension related to reward sensitivity, persistence and reactivity-the Behavioural Approach System. We sought to clarify the nature of negative, and positive, affectivity in relation to handedness. ANOVAs and multiple regression analyses converged on the following conclusions: left-handers were higher on the BIS, not the FFFS, than right-handers; in right-handers only, strength of hand preference was positively correlated with the FFFS, not the BIS. The original assessment method proposed by Annett was also used to assess handedness, but associations with RST-PQ factors were not found. These findings help us to clarify existing issues in the literature and raise new ones for future research
The planetary system host HR\,8799: On its Bootis nature
HR\,8799 is a Bootis, Doradus star hosting a planetary
system and a debris disk with two rings. This makes this system a very
interesting target for asteroseismic studies. This work is devoted to the
determination of the internal metallicity of this star, linked with its
Bootis nature (i.e., solar surface abundances of light elements, and
subsolar surface abundances of heavy elements), taking advantage of its
Doradus pulsations. This is the most accurate way to obtain this
information, and this is the first time such a study is performed for a
planetary-system-host star. We have used the equilibrium code CESAM and the
non-adiabatic pulsational code GraCo. We have applied the Frequency Ratio
Method (FRM) and the Time Dependent Convection theory (TDC) to estimate the
mode identification, the Brunt-Va\"is\"al\"a frequency integral and the mode
instability, making the selection of the possible models. When the
non-seismological constraints (i.e its position in the HR diagram) are used,
the solar abundance models are discarded. This result contradicts one of the
main hypothesis for explaining the Bootis nature, namely the
accretion/diffusion of gas by a star with solar abundance. Therefore, according
to these results, a revision of this hypothesis is needed. The inclusion of
accurate internal chemical mixing processes seems to be necessary to explain
the peculiar abundances observed in the surface of stars with internal subsolar
metallicities. The use of the asteroseismological constraints, like those
provided by the FRM or the instability analysis, provides a very accurate
determination of the physical characteristics of HR 8799. However, a dependence
of the results on the inclination angle still remains. The determination of
this angle, more accurate multicolour photometric observations, and high
resolution spectroscopy can definitively fix the mass and metallicity of this
star.Comment: 11 pages, 10 figures. Accepted for publication in MNRA
Fast, scalable, Bayesian spike identification for multi-electrode arrays
We present an algorithm to identify individual neural spikes observed on
high-density multi-electrode arrays (MEAs). Our method can distinguish large
numbers of distinct neural units, even when spikes overlap, and accounts for
intrinsic variability of spikes from each unit. As MEAs grow larger, it is
important to find spike-identification methods that are scalable, that is, the
computational cost of spike fitting should scale well with the number of units
observed. Our algorithm accomplishes this goal, and is fast, because it
exploits the spatial locality of each unit and the basic biophysics of
extracellular signal propagation. Human intervention is minimized and
streamlined via a graphical interface. We illustrate our method on data from a
mammalian retina preparation and document its performance on simulated data
consisting of spikes added to experimentally measured background noise. The
algorithm is highly accurate
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