Steve Maddock

Dr. Steve Maddock

Computer Science, University of Sheffield, Sheffield, UK
orcid

Research Focus & Metrics

Academic Career Length

28Years (1999-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 June 2018 in The Journal of the Acoustical Society of America
Verified
Journal Article
Open access
PDF file
NANajwa Alghamdi
Najwa Alghamdi
SMSteve Maddock
Steve Maddock
RMRicard Marxer
Ricard Marxer
JBJon Barker
Jon Barker
GBGuy J. Brown
Guy J. Brown
This paper presents a bi-view (front and side) audiovisual Lombard speech corpus, which is freely available for download. It contains 5400 utterances (2700 Lombard and 2700 plain reference utterances), produced by 54 talkers, with each utterance in the dataset following the same sentence format as the audiovisual “Grid” corpus [Cooke, Barker, Cunningham, and Shao (2006). J. Acoust. Soc. Am. 120(5), 2421–2424]. Analysis of this dataset confirms previous research, showing prominent acoustic, phonetic, and articulatory speech modifications in Lombard speech. In addition, gender differences are observed in the size of Lombard effect. Specifically, female talkers exhibit a greater increase in estimated vowel duration and a greater reduction in F2 frequency.

7 June 2022 in Sensors
Verified
Journal Article
Open access
PDF file
TZTianhao Zhang
Tianhao Zhang
WAWaqas Aftab
Waqas Aftab
LYUDMILA MIHAYLOVALYUDMILA MIHAYLOVA
LYUDMILA MIHAYLOVA
CLChristian Langran-Wheeler
Christian Langran-Wheeler
Sam RigbySam Rigby
Sam Rigby
GBGarry Bosworth
Garry Bosworth
Railway networks systems are by design open and accessible to people, but this presents challenges in the prevention of events such as terrorism, trespass, and suicide fatalities. With the rapid advancement of machine learning, numerous computer vision methods have been developed in closed-circuit television (CCTV) surveillance systems for the purposes of managing public spaces. These methods are built based on multiple types of sensors and are designed to automatically detect static objects and unexpected events, monitor people, and prevent potential dangers. This survey focuses on recently developed CCTV surveillance methods for rail networks, discusses the challenges they face, their advantages and disadvantages and a vision for future railway surveillance systems. State-of-the-art methods for object detection and behaviour recognition applied to rail network surveillance systems are introduced, and the ethics of handling personal data and the use of automated systems are also considered.

1 November 2017 in Computers in Biology and Medicine
Verified
Journal Article
Open access
WSWuyang Shui
Wuyang Shui
MZMingquan Zhou
Mingquan Zhou
SMSteve Maddock
Steve Maddock
THTaiping He
Taiping He
XWXingce Wang
Xingce Wang
QDQingqiong Deng
Qingqiong Deng
Previous studies have used principal component analysis (PCA) to investigate the craniofacial relationship, as well as sex determination using facial factors. However, few studies have investigated the extent to which the choice of principal components (PCs) affects the analysis of craniofacial relationship and sexual dimorphism. In this paper, we propose a PCA-based method for visual and quantitative analysis, using 140 samples of 3D heads (70 male and 70 female), produced from computed tomography (CT) images. There are two parts to the method. First, skull and facial landmarks are manually marked to guide the model's registration so that dense corresponding vertices occupy the same relative position in every sample. Statistical shape spaces of the skull and face in dense corresponding vertices are constructed using PCA. Variations in these vertices, captured in every principal component (PC), are visualized to observe shape variability. The correlations of skull- and face-based PC scores are analysed, and linear regression is used to fit the craniofacial relationship. We compute the PC coefficients of a face based on this craniofacial relationship and the PC scores of a skull, and apply the coefficients to estimate a 3D face for the skull. To evaluate the accuracy of the computed craniofacial relationship, the mean and standard deviation of every vertex between the two models are computed, where these models are reconstructed using real PC scores and coefficients. Second, each PC in facial space is analysed for sex determination, for which support vector machines (SVMs) are used. We examined the correlation between PCs and sex, and explored the extent to which the choice of PCs affects the expression of sexual dimorphism. Our results suggest that skull- and face-based PCs can be used to describe the craniofacial relationship and that the accuracy of the method can be improved by using an increased number of face-based PCs. The results show that the accuracy of the sex classification is related to the choice of PCs. The highest sex classification rate is 91.43% using our method.

1 June 2018 in Speech Communication
Verified
Journal Article
Open access
RMRicard Marxer
Ricard Marxer
JBJon Barker
Jon Barker
NANajwa AlGhamdi
Najwa AlGhamdi
SMSteve Maddock
Steve Maddock

1 January 2005 in Computers in Entertainment
Verified
Journal Article
Open access
MMMichael Meredith
Michael Meredith
SMSteve Maddock
Steve Maddock
In this article we present a technique that enhances an inverse kinematics (IK) solver such that when the results are applied to a computer character, we can generate a level of individualization tailored to both the character and the environment, e.g., a walking motion can become "stiffer" or can be turned into a limping motion. Since the technique is based on an IK solver, we also have the desirable effect of solving retargetting issues when mapping motion data between characters. As the individualization aspect of our technique is very tightly coupled with the inverse kinematics solver, we can achieve both the individualization and retargetting of characters in real time.

4 July 2020 in Multimedia Tools and Applications
Verified
Journal Article
Closed access
PDF file
WSWuyang Shui
Wuyang Shui
MZMingquan Zhou
Mingquan Zhou
SMSteve Maddock
Steve Maddock
YJYuan Ji
Yuan Ji
QDQingqiong Deng
Qingqiong Deng
XWXiujie Wu
Xiujie Wu