All Outputs (28)

A 10:1 Bandwidth Cryogenic Quadruple-Ridged Flared Horn Design for Reflector Antennas in Radio Astronomy (2020)
Journal Article
Ma, Y., See, C. H., Pang, F., Wu, D., Liu, D., Abidin, Z. Z., …Abd-Alhameed, R. A. (2020). A 10:1 Bandwidth Cryogenic Quadruple-Ridged Flared Horn Design for Reflector Antennas in Radio Astronomy. IEEE Access, 8, 81101-81115. https://doi.org/10.1109/ACCESS.2020.2991350

A two port 2.4 to 24 GHz cryogenic Quadruple-Ridged Flared Horn (QRFH) Feed with 10:1 impedance bandwidth is selected for presentation and investigation in this paper. The antenna geometry is formed by using simulation-based optimization which s... Read More about A 10:1 Bandwidth Cryogenic Quadruple-Ridged Flared Horn Design for Reflector Antennas in Radio Astronomy.

Modelling IoT devices communication employing representative operation modes to reveal traffic generation characteristics (2019)
Journal Article
Barakat, B., Keates, S., Wassell, I. J., & Arshad, K. (2021). Modelling IoT devices communication employing representative operation modes to reveal traffic generation characteristics. International Journal of Parallel, Emergent and Distributed Systems, 36(2), 117-129. https://doi.org/10.1080/17445760.2019.1649402

Several traffic models for the Internet of Things (IoT) have been proposed in the literature. However, they can be considered as heuristic models since they only reflect the stochastic characteristic of the generated traffic. In this paper, we propos... Read More about Modelling IoT devices communication employing representative operation modes to reveal traffic generation characteristics.

Is the Zero-Wait Policy Always Optimum for Information Freshness (Peak Age) or Throughput? (2019)
Journal Article
Barakat, B., Keates, S., Wassell, I., & Arshad, K. (2019). Is the Zero-Wait Policy Always Optimum for Information Freshness (Peak Age) or Throughput?. IEEE Communications Letters, 23(6), 987-990. https://doi.org/10.1109/LCOMM.2019.2907935

The Zero-Wait (ZW) policy is widely held to achieve maximum information 'freshness', i.e., to achieve minimum Peak Age (PA) and maximum throughput, for real-time Internet-of-Things applications. In this paper, it was shown through a series of experim... Read More about Is the Zero-Wait Policy Always Optimum for Information Freshness (Peak Age) or Throughput?.

When Universal Access is not quite universal enough: Case studies and lessons to be learned (2018)
Journal Article
Keates, S. (2020). When Universal Access is not quite universal enough: Case studies and lessons to be learned. Universal Access in the Information Society, 19, 133-144. https://doi.org/10.1007/s10209-018-0636-2

While the theory of designing for Universal Access is increasingly understood, there remain persistent issues over realising products and systems that meet the goal of being accessible and usable by the broadest possible set of users. Clearly product... Read More about When Universal Access is not quite universal enough: Case studies and lessons to be learned.

Simultaneous Bayesian Clustering and Feature Selection Through Student’s ${t}$ Mixtures Model (2017)
Journal Article
Sun, J., Zhou, A., Keates, S., & Liao, S. (2018). Simultaneous Bayesian Clustering and Feature Selection Through Student’s ${t}$ Mixtures Model. IEEE Transactions on Neural Networks and Learning Systems, 29(4), 1187-1199. https://doi.org/10.1109/tnnls.2016.2619061

In this paper, we proposed a generative model for feature selection under the unsupervised learning context. The model assumes that data are independently and identically sampled from a finite mixture of Student?s t distributions, which can reduce th... Read More about Simultaneous Bayesian Clustering and Feature Selection Through Student’s ${t}$ Mixtures Model.

Measuring acceptable input: What is "good enough"? (2016)
Journal Article
Keates, S. (2017). Measuring acceptable input: What is "good enough"?. Universal Access in the Information Society, 16(3), 713-723. https://doi.org/10.1007/s10209-016-0498-4

Many new assistive input systems developed to meet the needs of users with functional impairments fail to make it out of the research laboratory and into regular use by the intended end users. This paper examines some of the reasons for this failure... Read More about Measuring acceptable input: What is "good enough"?.

A pedagogical example of teaching Universal Access (2015)
Journal Article
Keates, S. (2015). A pedagogical example of teaching Universal Access. Universal Access in the Information Society, 14(1), 97-110. https://doi.org/10.1007/s10209-014-0398-4

Designing for Universal Access requires designers to have a good understanding of the full range of users and their capabilities, appropriate datasets, and the most suitable tools and techniques. Education clearly plays an important role in helping d... Read More about A pedagogical example of teaching Universal Access.

Subdivision surface fitting to a dense mesh using ridges and umbilics (2014)
Journal Article
Ma, X., Keates, S., Jiang, Y., & Kosinka, J. (2015). Subdivision surface fitting to a dense mesh using ridges and umbilics. Computer Aided Geometric Design, 32, 5-21. https://doi.org/10.1016/j.cagd.2014.10.001

Fitting a sparse surface to approximate vast dense data is of interest for many applications: reverse engineering, recognition and compression, etc. The present work provides an approach to fit a Loop subdivision surface to a dense triangular mesh of... Read More about Subdivision surface fitting to a dense mesh using ridges and umbilics.

Canonical correlation analysis on data with censoring and error information (2013)
Journal Article
Sun, J., & Keates, S. (2013). Canonical correlation analysis on data with censoring and error information. IEEE Transactions on Neural Networks and Learning Systems, 24(12), 1909-1919. https://doi.org/10.1109/TNNLS.2013.2262949

We developed a probabilistic model for canonical correlation analysis in the case when the associated datasets are incomplete. This case can arise where data entries either contain measurement errors or are censored (i.e., nonignorable missing) due t... Read More about Canonical correlation analysis on data with censoring and error information.

Designing user interfaces for "ordinary users in extraordinary circumstances": a keyboard-only web-based application for use in airports (2012)
Journal Article
Keates, S. (2013). Designing user interfaces for "ordinary users in extraordinary circumstances": a keyboard-only web-based application for use in airports. Universal Access in the Information Society, 12(2), 205-216. https://doi.org/10.1007/s10209-012-0276-x

Universal Access is commonly interpreted as focusing on designing for users with atypical requirements—specifically users with disabilities or older adults. However, Universal Access is also about providing access to users in all situations and circu... Read More about Designing user interfaces for "ordinary users in extraordinary circumstances": a keyboard-only web-based application for use in airports.

Human-machine design considerations in advanced machine-learning systems (2011)
Journal Article
Keates, S., Varker, P., & Spowart, F. (2011). Human-machine design considerations in advanced machine-learning systems. IBM Journal of Research and Development, 55(5), 4:1-4:10. https://doi.org/10.1147/JRD.2011.2163274

This paper explores issues related to human–computer interaction with the new class of machine-learning systems that represent an exciting development on the frontiers of information technology. These systems represent a significant breakthrough in h... Read More about Human-machine design considerations in advanced machine-learning systems.

Individual responses to a method of cursor assistance (2008)
Journal Article
Trewin, S., Keates, S., & Moffatt, K. (2008). Individual responses to a method of cursor assistance. Disability and Rehabilitation: Assistive Technology, 3(1-2), 2-21. https://doi.org/10.1080/17483100701273128

Purpose. The aim of this study was to evaluate a new click assistance technique, Steady Clicks, designed to help computer users with motor impairments to click more accurately using a mouse. Specifically, Steady Clicks suppresses two types of errors:... Read More about Individual responses to a method of cursor assistance.

Cognitive and learning difficulties and how they affect access to IT systems (2007)
Journal Article
Keates, S., Adams, R., Bodine, C., Czaja, S., Gordon, W., Gregor, P., …Varker, P. (2007). Cognitive and learning difficulties and how they affect access to IT systems. Universal Access in the Information Society, 5(4), 329-339. https://doi.org/10.1007/s10209-006-0058-4

In October 2005, the IBM Human Ability and Accessibility Center and T.J. Watson Research Center hosted a symposium on "cognitive and learning difficulties and how they affect access to IT systems." The central premise of the symposium was the recogni... Read More about Cognitive and learning difficulties and how they affect access to IT systems.

Pragmatic research issues confronting HCI practitioners when designing for universal access (2006)
Journal Article
Keates, S. (2006). Pragmatic research issues confronting HCI practitioners when designing for universal access. Universal Access in the Information Society, 5(3), 269-278. https://doi.org/10.1007/s10209-006-0050-z

Many HCI products exclude potential users unnecessarily. Such exclusion often arises because of a mismatch between designers? perceptions of the wants and needs of the end-user and their actual wants and needs. Sometimes the mismatch originates from... Read More about Pragmatic research issues confronting HCI practitioners when designing for universal access.

Improving Web accessibility through an enhanced open-source browser (2005)
Journal Article
Hanson, V. L., Brezin, J. P., Crayne, S., Keates, S., Kjeldsen, R., Richards, J. T., …Trewin, S. (2005). Improving Web accessibility through an enhanced open-source browser. IBM Systems Journal, 44(3), 573-588. https://doi.org/10.1147/sj.443.0573

The accessibility Works project provides software enhancements to the Mozilla? Web browser and allows users to control their browsing environment. Although Web accessibility standards specify markup that must be incorporated for Web pages to be acces... Read More about Improving Web accessibility through an enhanced open-source browser.

Movement time for motion-impaired users assisted by force-feedback: effects of movement amplitude, target width, and gravity well width (2005)
Journal Article
Hwang, F., Keates, S., Langdon, P., & Clarkson, P. J. (2005). Movement time for motion-impaired users assisted by force-feedback: effects of movement amplitude, target width, and gravity well width. Universal Access in the Information Society, 4, 85-95. https://doi.org/10.1007/S10209-005-0114-5

This paper presents a study investigating how the performance of motion-impaired computer users in ?point and click? tasks varies with target distance (A), target width (W), and force-feedback gravity well width (GWW). Six motion-impaired users perfo... Read More about Movement time for motion-impaired users assisted by force-feedback: effects of movement amplitude, target width, and gravity well width.

Critical user forums - an effective user research method for inclusive design (2005)
Journal Article
Dong, H., Clarkson, P. J., Cassim, J., & Keates, S. (2005). Critical user forums - an effective user research method for inclusive design. Design Journal, 8(2), 49-59. https://doi.org/10.2752/146069205789331628

Inclusive or universal design is about designing more accessible products and services for the widest possible range of users, regardless of age and capabilities. It requires better understanding and empathy with all potential users. Traditional user... Read More about Critical user forums - an effective user research method for inclusive design.

A submovement analysis of cursor trajectories (2005)
Journal Article
Hwang, F., Keates, S., Langdon, P., & Clarkson, J. (2005). A submovement analysis of cursor trajectories. Behaviour and Information Technology, 24(3), 205-217. https://doi.org/10.1080/01449290412331327474

Understanding human movement is key to improving input devices and interaction techniques. This paper presents a study of mouse movements of motion-impaired users, with an aim to gaining a better understanding of impaired movement. The cursor traject... Read More about A submovement analysis of cursor trajectories.

Investigating perceptions of manufacturers and retailers to inclusive design (2004)
Journal Article
Dong, H., Clarkson, P. J., Ahmed, S., & Keates, S. (2004). Investigating perceptions of manufacturers and retailers to inclusive design. Design Journal, 7(3), 3-15. https://doi.org/10.2752/146069204789338398

This paper describes a study into industry perceptions of barriers and drivers for inclusive design. The study investigated perceptions of manufacturers and retailers of consumer products in the United Kingdom (UK) and compared their perceptions with... Read More about Investigating perceptions of manufacturers and retailers to inclusive design.

Design for participation: providing access to e-information for older adults (2004)
Journal Article
Keates, S., Clarkson, P. J., & Robinson, P. (2004). Design for participation: providing access to e-information for older adults. Universal Access in the Information Society, 3(2), 149-163. https://doi.org/10.1007/s10209-004-0093-y

Electronic information sources are becoming increasingly more prolific and offer a huge potential for those able to use them. However, for those unable to access those services, there is the risk of being further disadvantaged by continued exclusion... Read More about Design for participation: providing access to e-information for older adults.