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Background: Publicly-available speech corpora facilitate reproducible research by providing open-access data for participants who have consented/assented to data sharing among different research teams. Such corpora can also support clinical education, including perceptual training and training in the use of speech analysis tools.Purpose: In this Research Note, we introduce the PERCEPT-R and PERCEPT-GFTA corpora, which together contain over 36 hours of speech audio (> 125,000 syllable, word, and phrase utterances) from children, adolescents, and young adults aged 6-24 with speech sound disorder (primarily residual speech sound disorders impacting /ɹ/) and age-matched peers. We highlight PhonBank as the repository for the corpora and demonstrate use of the associated speech analysis software, Phon, to query the corpus. A worked example of research with PERCEPT-R, suitable for clinical education and research training, is included as an appendix. Support for end users and information/descriptive statistics for future releases of the PERCEPT Corpus can be found in a dedicated Slack channel. Finally, we discuss the potential for PERCEPT corpora to support the training of artificial intelligence clinical speech technology appropriate for use with children with speech sound disorders, the development of which has historically been constrained by the limited representation of either children or individuals with speech impairments in publicly available training corpora. Conclusion: We demonstrate the use of PERCEPT corpora, PhonBank, and Phon for clinical training and research questions appropriate to child citation speech. Increased use these tools has the potential to enhance reproducibility in the study of speech development and disorders.

We present the PERCEPT-R corpus, a labeled corpus of child speakers of American English with typical speech and residual speech sound disorders affecting rhotics. We demonstrate the utility of age-and-gender normalized formants extracted from PERCEPT-R in training support vector classifiers to predict ground-truth perceptual judgments of “rhotic” (i.e., dialect-typical) and clinical “derhotic” /ɹ/ for novel speakers (mean of participant-specific f-metrics = .83; SD = .18, N = 281).

This research was funded through the American Speech and Hearing Foundation's 2012 StudentResearch Grant in Early Childhood Language Development awarded to Vanessa Harwood as well as an anonymous generous donation to Haskins Laboratories. Electrophysiological measures of language within early childhood provide important information about neurolinguistic development. We investigated associations between amplitude and latency of the P1 and N2 event-related potential components in response to spoken pseudowords, and clinical measures of language performance within a sample of 58 typically developing children between 24 and 48 months. N2 amplitude differences between repeated and new tokens were correlated with measures of expressive and receptive language and speech sound production. Phonemic sensitivity measured by the N2 component may reflect the integrity of neural networks that are important for speech perception and production in young children.

Elastin fibers assemble in the extracellular matrix from the precursor protein tropoelastin and provide the flexibility and spontaneous recoil required for arterial function. Unlike many proteins, a structure-function mechanism for elastin has been elusive. We have performed detailed NMR relaxation studies of the dynamics of the minielastins 24x′ and 20x′ using solution NMR, and of purified bovine elastin fibers in the presence and absence of mechanical stress using solid state NMR. The low sequence complexity of the minielastins enables us to determine average dynamical timescales and degrees of local ordering in the cross-link and hydrophobic modules separately using NMR relaxation by taking advantage of their residue-specific resolution. We find an extremely high degree of disorder, with order parameters for the entirety of the hydrophobic domains near zero, resembling that of simple chemical polymers and less than the order parameters that have been observed in other intrinsically disordered proteins. We find that average backbone order parameters in natural, purified elastin fibers are comparable to those found in 24x′ and 20x′ in solution. The difference in dynamics, compared with the minielastins, is that backbone correlation times are significantly slowed in purified elastin. Moreover, when elastin is mechanically stretched, the high chain disorder in purified elastin is retained, showing that any change in local ordering is below that detectable in our experiment. Combined with our previous finding of a 10-fold increase in the ordering of water when fully hydrated elastin fibers are stretched by 50%, these results support the hypothesis that stretch induced solvent ordering, i.e., the hydrophobic effect, is a key player in the elastic recoil of elastin as opposed to configurational entropy loss.

After a stroke, it is highly likely that an individual will experience substantial fatigue that can significantly affect recovery and function; stroke survivors also have more than a 50% chance of having at least one communication disorder. Current reviews of post-stroke fatigue have not provided evidence focused on communication disorders or the potential influence they may have on post-stroke fatigue and related recovery. The aim of this review was to determine how communication disorders are represented in post-stroke fatigue research and to catalogue methods used to identify communication disorders and measure fatigue. A systematic scoping review was conducted to identify studies measuring post-stroke fatigue. To identify these studies, a comprehensive literature search was conducted using relevant databases and grey literature sources, followed by several stages of review that adhered to PRISMA guidelines. We evaluated these studies using pre-established eligibility criteria and extracted data regarding the inclusion/exclusion of persons with communication disorders and the assessment methods used. The scoping review analysis was conducted on 161 studies. Of these, 41 (26%) excluded all communication disorders, 71 (44%) excluded severe communication disorders, and 49 (30%) included participants with communication disorders. Of the 120 studies that did not explicitly exclude all communication disorders, only 34 were confirmed to report data from at least one person with a communication disorder. Further, only 5 studies reported data that could be used to determine a relationship between these co-morbidities. Persons with communication disorders are underrepresented in post-stroke fatigue research and very few studies have examined the relationship between post-stroke fatigue and communication disorders, limiting conclusions that can be drawn. This is problematic because medical professionals relying on this evidence to guide clinical practice are likely to be treating individuals with co-occurring fatigue and communication disorders and the current research does not provide enough information about the potential impact of fatigue on communication disorders or vice versa. To bridge this gap, we suggest methods of assessment that could provide ways to more accurately 1) reflect the real patient population in post-stroke fatigue studies, and 2) measure and document fatigue in post-stroke communication disorder studies.

Railway infrastructure already has some ‘smart’ characteristics, in that it ‘knows’ where trains are located and can sometimes detect track and other equipment faults. There is considerable scope to increase these capabilities. There is also a significant and urgent need for such improvements: railways have limited operational flexibility and face increasing passenger and freight traffic demand on existing infrastructure. The reliable provision of additional capacity requires improved system ‘self-knowledge’ for traffic control and management purposes, as well as for system reliability and safety. The use of smart infrastructure for fault prediction and the guidance of preventive maintenance helps to maintain operational capacity. This approach also helps to reduce track access requirements for traditional maintenance and renewals activities, thus increasing network availability and total capacity. Climate change presents the railway industry with significant challenges, notably in terms of flooding and earthworks failures resulting from increased rainfall intensity. Smart infrastructure includes the prediction and monitoring of such events to maintain safety and enable the timely implementation of operational contingency plans. This paper draws upon a range of sources to identify the needs for and potential benefits of increased deployment of smart infrastructure and other assets on railways in Britain and elsewhere.

Elastin fibers assemble in the extracellular matrix from the precursor protein tropoelastin and provide the flexibility and spontaneous recoil required for arterial function. Unlike many proteins, a structure-function mechanism for elastin has been elusive. We have performed detailed NMR relaxation studies of the dynamics of the minielastins 24x′ and 20x′ using solution NMR, and of purified bovine elastin fibers in the presence and absence of mechanical stress using solid state NMR. The low sequence complexity of the minielastins enables us to determine dynamical timescales and degrees of local ordering with residue-specific resolution in the cross-link and hydrophobic modules using NMR relaxation. We find an extremely high degree of disorder, with order parameters for the entirety of the hydrophobic domains near zero, resembling that of simple chemical polymers and less than the order parameters that have been observed in other intrinsically disordered proteins. We find that backbone order parameters in natural, purified elastin fibers are comparable to those found in 24x′ and 20x′ in solution. The difference in dynamics, compared to the minielastins, is that backbone correlation times are significantly slowed in purified elastin. Moreover, when elastin is mechanically stretched, the high chain disorder in purified elastin is retained - showing that any change in local ordering is below that detectable in our experiment. Combined with our previous finding of a 10-fold increase in the ordering of water when fully hydrated elastin fibers are stretched by 50%, these results support the hypothesis that stretch induced solvent ordering, i.e., the hydrophobic effect, is a key player in the elastic recoil of elastin as opposed to configurational entropy loss.SIGNIFICANCEElastin is responsible for the spontaneous recoil of arterial walls that is necessary for cardiovascular function. Despite this critical role, the mechanism driving entropic recoil has remained unclear. Elastin is unusual in that it is intrinsically disordered in both soluble and fibrous forms. Using NMR, we have determined the timescales and amplitudes of dynamics in two soluble elastin mimetics and in relaxed and stretched states of purified bovine elastin fibers. Although dynamical timescales are different, both the soluble elastin mimetic and fibrillar elastin display an exceptionally high degree of disorder. No detectable increase in protein ordering was observed upon stretching, suggesting that entropic recoil is primarily driven by the hydrophobic effect and not configurational entropy loss.

Local Government Authorities (LGAs) are typically responsible for roads outside a country’s strategic road network. LGAs play a key role therefore in facilitating the reduction of emissions from road traffic in urban areas, and must engage in emissions modelling to assess the impact(s) of transport interventions. Previous research has identified a requirement for road traffic Emissions Models (EMs) that balance capturing the impact on emissions of vehicle dynamics (e.g. due to congestion) against in-use practicality. This study developed such an EM through investigating the prediction of network-level carbon dioxide (CO2) emissions based on readily available data generated by Inductive Loop Detectors (ILDs) installed as part of Urban Traffic Control (UTC) systems. Using Southampton, UK as a testbed, 514 GPS driving patterns (1 Hz speed-time profiles) were collected from 49 drivers of different vehicle types and used as inputs to an Instantaneous EM to calculate accurate vehicle emissions. In parallel, concurrent data were collected from ILDs crossed by vehicles during their journeys. Statistical analysis was used to examine relationships between traffic variables derived from the ILD data (predictor variables) and accurate emissions (outcome variable). Results showed that ILD data (when used in conjunction with categorisation of vehicle types) can form the basis for a practical road traffic CO2 EM that outperforms the next-best alternative EM available to LGAs, with mean predictions found to be 2% greater than proxy real-world values.

Artificial minielastin constructs have been designed which replicate the structure and function of natural elastins in a simpler context, allowing the NMR observation of structure and dynamics of elastin-like proteins with complete residue-specific resolution. We find that the alanine-rich crosslinking domains of elastin have partially helical structure, but only when capped by proline-rich hydrophobic domains. We also find that the hydrophobic domains, composed of prominent 6-residue repeats VPGVGG and APGVGV found in natural elastins appear random coil by both NMR chemical shift analysis and circular dichroism. However, these elastin hydrophobic domains exhibit structural bias for a dynamically disordered conformation that is neither helical nor beta sheet with a degree of non-random structural bias which is dependent on residue type and position in the sequence. Another non-random-coil aspect of hydrophobic domain structure lies in the fact that, in contrast to other intrinsically disordered proteins, these hydrophobic domains retain a relatively condensed conformation whether attached to crosslinking domains or not. Importantly, these domains and the proteins containing them constrict with increasing temperature by up to 30% in volume without becoming more ordered. This property is often observed in non-biological polymers, and suggests that temperature-driven constriction is a new type of protein structural change that is linked to elastin’s biological functions of coacervation-driven assembly and elastic recoil.

As traffic levels increase on railways in Britain and elsewhere, improved understanding of the trade-offs between capacity provision/utilisation and service quality is increasingly important, as Infrastructure Managers and Railway Undertakings seek to maximise capacity provision without an unacceptable loss of service reliability and punctuality. This is particularly true of the stations and junctions forming the nodes of railway networks, as they tend to be the capacity bottlenecks, and the relationships between capacity utilisation and performance are less well understood for nodes than for their intermediate links. Following on from initial work undertaken for the OCCASION project on the calculation of nodal Capacity Utilisation Indices, and on the application of the techniques developed for OCCASION to the recalibration of the Capacity Charge element of the Track Access Charges on Britain’s railways, one of the objectives of the DITTO Rail Systems project is the further investigation of the relationship(s) between capacity utilisation and performance, as indicated by levels of congestion-related reactionary delay, at railway stations and junctions. Historic timetable and delay data for selected stations have been used to investigate these relationships, which take the expected form and tend to suggest lower maximum capacity utilisation levels for stations than for the links between them. Work is ongoing to develop these datasets and relationships further, and to identify suitable capacity utilisation upper limit values.

Multicore processors offer significant advantages of weight, power, and space to embedded real-time developers, making their adoption almost inevitable. Also, system sustainability and economies of scale will increasingly make multicore devices indispensable. However, predictability of performance, specifically, establishing realistic upper bounds on execution time for schedulability analysis is a significant challenge to certification. This paper describes a methodology for empirically establishing a reasonable, high-confidence upper bound for cache interference effects in the context of engineering practices commonly used in certifiable real-time systems.

Depending on the method of electricity generation, mass-market penetration of electric vehicles has the potential to reduce emissions of greenhouse gases and air pollutants considerably, and to reduce dependency on fossil fuels. This paper presents a novel methodology for Local Government Authorities (LGAs) to identify suitable locations for the initial provision of residential on-street Plug-in Electric Vehicle (PEV) charging infrastructure in urban areas to help remove barriers to PEV uptake. The methodology is practical for use by LGAs with limited financial resources as it is based on simple Geographic Information System (GIS) analysis of routinely available census and parking data to identify the spatial overlaps between areas where residents are most likely to be PEV users and areas where there is a high reliance on residential on-street parking. The methodology has been implemented in practice to determine a charging infrastructure installation strategy for Southampton, UK, where 128 streets (out of 1924 in total) were recommended as suitable locations. These streets were reviewed by a group of experts during a workshop and confirmed as suitable locations for the initial installation of residential on-street charge points in the city.

This paper presents issues, trade-offs and challenges encountered while developing a UK national transport model as part of a large interdisciplinary project, ITRC MISTRAL. The Infrastructure Transitions Research Consortium (ITRC) is a consortium of seven leading UK universities focusing on analysis of national infrastructure systems using a system-of-systems approach. In this paper, we describe a multi-modal multi-scale national transport model being developed by ITRC which includes passenger and freight transport via highways, railways, airports, seaports and local transit networks. The model predicts future demand for each mode on individual flows using an elasticity-based simulation approach. These flows are then assigned to transport networks to assess infrastructure capacity utilisation and obtain new estimates of inter-zonal travel times. The model explicitly considers cross-sectoral interdependencies with other infrastructure networks, including the energy sector (where transport is the largest consuming sector), digital communications (which provide bandwidth to passengers and enable smart mobility), waste management (which requires transport services) and water supply (where flooding poses a major risk of transport disruptions). It is also planned to be capable of estimating environmental emissions and assessing the vulnerability and resilience to risk of transport systems. The enhanced transport model discussed here builds on an existing modelling framework which has been used by the UK government to inform their National Infrastructure Assessment. As such, the model has the potential to support policy making with regards to infrastructure investment on a decadal scale, under a range of possible future scenarios including population growth, new technologies and climate change.

HighlightsEmpirical evidence that search-based optimization of software deployment, using placement heuristics designed to increase cache performance, can yield substantial performance benefits.SMACK, a formalized and minimalistic model for calculating the relative cache performance increase of various software deployments.Detailed discussion on the challenges of considering cache effects when optimizing software system deployment. System performance improvements are critical for the resource-limited environment of multiple integrated applications executing inside a single distributed real-time and embedded (DRE) system, such as integrated avionics platform or vehtronics systems. While processor caches can effectively reduce execution time there are several factors, such as cache size, system data sharing, and task execution schedule, which make it hard to quantify, predict, and optimize the cache usage of a DRE system. This article presents SMACK, a novel heuristic for estimating the hardware cache usage of a DRE system, and describes a method of varying the runtime behavior of DRE system software without (1) requiring extensive safety recertification or (2) violating the real-time scheduling deadlines. By using SMACK as a maximization target, we were able to reduce integrated DRE system execution time by an average of 2.4% and a maximum of 4.34%.

The reality of anthropogenic climate change is increasingly apparent, with significant implications for railway and other infrastructure networks. As a transport mode with a relatively small environmental impact, rail has a potentially valuable role to play in climate change mitigation. However, this potential can only be realised if railways are adapted to withstand the effects of the increasingly extreme weather associated with climate change predictions. This requirement is widely acknowledged by government and the railway industry, and the required responses to the specific potential effects of climate change are well-known and understood. However, a review of the literature indicates a need for a decision support system to prioritise the interventions required for adaptation in the face of considerable uncertainty about both the frequency and scale of future extreme weather events, and the nature and levels of future passenger and freight traffic on the railways. This paper proposes a seven-step framework for the classification of the railway network, the assessment of the economic value of traffic using the network (and thus the economic costs of weather-related disruption), the identification of appropriate remedial measures and their costs, and thus the prioritisation of these measures by means of cost-benefit analysis.

As the demand for passenger and freight transport on Britain’s railways increases, providing additional capacity and making the best use of the existing infrastructure are priorities for the industry. Since the stations and junctions forming the nodes of the railway network tend to form the constraints on route and network capacity, improved understanding of their operation and capacity characteristics is particularly important. This paper describes the research undertaken to improve the understanding of nodal capacity and capacity utilisation, and to route and schedule trains more efficiently through nodes, thus improving service quality and/or releasing capacity for additional train services.

Within the transport sector, modal shift towards more efficient and less polluting modes could be a key policy goal to help meet targets to reduce energy consumption and carbon emissions. However, making comparisons between modes is not necessarily straightforward. Average energy and emissions data are often relied upon, particularly for, rail, which may not be applicable to a given context. Some UK train operating companies have recently fitted electricity metres to their trains, from which energy consumption data have been obtained. This has enabled an understanding to be gained of how energy consumption and related emissions are affected by a number of factors, including train and service type. Comparisons are made with existing data for road and rail. It is noted that although more specific data can be useful in informing policy and making some decisions, average data continue to play an important role when considering the overall picture.

The International Conference Series on Competition and Ownership in Land Passenger Transport (known as the Thredbo Series) has been held biennially since the first conference in Thredbo, Australia in 1989. The objective of the conference series is to provide an international forum to examine competition and ownership issues in public transport, reporting on recent research and experience and developing conclusions on key themes. The focus is on determining the effects of different forms of competition, ownership and organization for land-based passenger transport on operators, users, governments/funders and society as a whole.

A variety of networking standards have been proposed and implemented to provide real-time network performance guarantees in embedded systems. These standards all focus on bounding individual message latency; however, we argue that this is not the most important measure for a large class of avionic systems. We show the key metric for this class of architectures, and present the results of an experiment using standard commercial-grade Gigabit Ethernet equipment to assess the suitability of COTS components in this environment. The path to more affordable future avionic architectures may be open now.

Given the major changes that have occurred to the organization of Britain's railways during 1994, this seems an appropriate time to compare their performance with those of the rest of western Europe. This article reports on work which repeated the major comparative study carried out by the authors in 1979. At that time, British Rail had relatively high labour productivity and a high degree of cost coverage, but high prices, low train loads and a low’ market share. In general these characteristics remain the case, with a further major improvement in productivity and financial performance in the 1980s, but a faster loss of market share than elsewhere in western Europe.

This work applied particle swarm heuristic optimization techniques to the problem of finding a near-optimal order in which to schedule tasks in a real-time embedded system in order to minimize cache miss rates experienced by the software. Reducing the number of cache misses is an important component of runtime execution efficiency. We demonstrated runtime reductions of 3-5% in execution time, significant for embedded systems attempting to add new capability without upgrading hardware. The expectation is that these gains can be improved further by the use of hardware with pseudo-LRU cache behavior.

Integrated applications running in multitenant environments are often subject to quality-of-service (QoS) requirements, such as resource and performance constraints. It is hard to allocate resources between multiple users accessing these types of applications while meeting all QoS constraints, such as ensuring users complete execution prior to deadlines. Although a processor cache can reduce the time required for the tasks of a user to execute, multiple task execution schedules may exist that meet deadlines but differ in cache utilization efficiency. Determining which task execution schedules will utilize the processor cache most efficiently and provide the greatest reductions in execution time is hard without jeopardizing deadlines. The work in this paper provides three key contributions to increasing the execution efficiency of integrated applications in multi-tenant environments while meeting QoS constraints. First, we present cache-aware metascheduling, which is a novel approach to modifying system execution schedules to increase cache-hit rate and reduce system execution time. Second, we apply cache-aware metascheduling to 11 simulated software systems to create 2 different execution schedules per system. Third, we empirically evaluate the impact of using cache-aware metascheduling to alter task schedules to reduce system execution time. Our results show that cache-aware metascheduling increases cache performance, reduces execution time, and satisfies scheduling constraints and safety requirements without requiring significant hardware or software changes.

As hydrocarbon prices continue to fluctuate, it is imperative for engineers to come-up with optimum and cost effective ways of managing and developing a field. This is especially true in heavy oil operations, where the margins are very small. So it is pertinent to gain a better and broader understanding on how completion techniques can be optimized to gain the maximum value for companies. This work presents an analysis/evaluation of gravel packs and slotted liners in a heavy oil field in California. The objective of this work is to compare gravel packs and slotted liners from a production and sand control standpoint. This work also has a secondary objective of re-evaluating the performance of old gravel pack wells that have been sidetracked using slotted liners. The result of this work indicates that there is not a "one size fits all" solution to the problem of sanding in the field. So, it is imperative that all feasible completion techniques be analyzed and their impact on production and economics be considered. The conclusions and recommendations from this study will provide an insight through which Petroleum Engineers in heavy oil operations will make educated decisions on how to optimally complete a field and also obtain the most value for the investment.

There has long been conflict over the degree to which railways should follow commercial or social investment criteria. This paper outlines the components of a comprehensive social cost‐benefit analysis of railway investment, and then describes the current approach in Britain. British Rail investment proposals are subject to a purely financial appraisal, although in the subsidized sectors of the railway this is subject to the proviso that a ‘broadly comparable’ level of service should be maintained. Local authorities and private operators are able to apply for a central government grant towards the cost of schemes they sponsor. But grant is only payable in respect of external benefits—that is, benefits other than to public transport users. Sponsors are also expected to seek contributions from private developers wherever possible. The difficulties to which this approach leads are discussed, and illustrated with two case studies of actual schemes. In one, it appears that failing to consider disbenefits to bu...

This paper examines the effects of the 1985 Transport Act on the local bus industry in Great Britain. An immediate distinction is made between the “commercial sector” that is run without subsidy and the “tendered sector” which receives subsidy administered by a system of competitive tendering. It is argued that the theory of contestable markets does not appear useful in explaining all aspects of competition in the commercial sector. Instead, duopoly models based on game theory might be more useful. They are shown to help explain entry deterrence strategies, predatory behaviour, the trend to mergers/acquisitions, the tendency for competition to lead to high frequency/fare combinations and the pressures towards collusion. By contrast, it is argued that the tendered sector is inherently more contestable than the commercial sector. It is concluded that there are important lessons to be learnt from British experience, particularly for regulators and legislators.