16,232 research outputs found
An exploratory survey of current practice in the medical device industry
This article is (c) Emerald Group Publishing and permission has been granted for this version to appear here. Emerald does not grant permission for this article to be further copied/distributed or hosted elsewhere without the express permission from Emerald Group Publishing Limited.Purpose – This study seeks to examine the extent to which mainstream tools and strategies are applied in the medical devices sector, which is highly fragmented and contains a high percentage of small companies, and to determine if company size impacts on manufacturing strategy selection.
Design/methodology/approach – A questionnaire was developed and disseminated through a number of channels. Responses were received from 38 companies in the UK and Ireland, describing 68 products taken to market in the past five years.
Findings – Because of the limited scope of the survey, the findings are indicative rather than conclusive, and interesting trends have emerged. New to the world products were much more likely to exceed company expectations of market success compared to derivative products. It was found that the majority of these innovative products were developed by small companies. Large companies appear to favour minor upgrades over major upgrades even though these prove – on the data presented – to be less successful overall.
Practical implications – These results provide those engaged in this sector with comparative information and some insights for further improvement. The reported trends with respect to company size and product complexity (or degree of novelty) are particularly illuminating. Academically, this sets some expected trends on a firmer footing and unearths one or two unexpected findings.
Originality/value – It is believed that this is the largest survey of determinants of success in UK medical device companies and it provides a comparison with other sectors
Reliable data delivery in low energy ad hoc sensor networks
Reliable delivery of data is a classical design goal for reliability-oriented collection routing protocols for ad hoc wireless sensor networks (WSNs). Guaranteed packet delivery performance can be ensured by careful selection of error free links, quick recovery from packet losses, and avoidance of overloaded relay sensor nodes. Due to limited resources of individual senor nodes, there is usually a trade-off between energy spending for packets transmissions and the appropriate level of reliability. Since link failures and packet losses are unavoidable, sensor networks may tolerate a certain level of reliability without significantly affecting packets delivery performance and data aggregation accuracy in favor of efficient energy consumption. However a certain degree of reliability is needed, especially when hop count increases between source sensor nodes and the base station as a single lost packet may result in loss of a large amount of aggregated data along longer hops. An effective solution is to jointly make a trade-off between energy, reliability, cost, and agility while improving packet delivery, maintaining low packet error ratio, minimizing unnecessary packets transmissions, and adaptively reducing control traffic in favor of high success reception ratios of representative data packets. Based on this approach, the proposed routing protocol can achieve moderate energy consumption and high packet delivery ratio even with high link failure rates. The proposed routing protocol was experimentally investigated on a testbed of Crossbow's TelosB motes and proven to be more robust and energy efficient than the current implementation of TinyOS2.x MultihopLQI
Dual Labour Markets and Menu Costs: Explaining the Cyclicality of Productivity and Wage Differentials
The conventional menu cost framework performs poorly with realistic labour supply elasticities; the menu costs required for price rigidity are very high and the welfare consequences of monetary disturbances are negligible. We show that the presence of dual labour markets greatly improves the performance of the framework both by reducing menu cost requirements and by boosting the welfare consequences. In addition, the introduction of dual labour markets provides an explanation of procyclical productivity and the shrinking of wage differentials during booms, in line with stylized facts on business cycles.
Innermost Stable Circular Orbit of a Spinning Particle in Kerr Spacetime
We study stability of a circular orbit of a spinning test particle in a Kerr
spacetime. We find that some of the circular orbits become unstable in the
direction perpendicular to the equatorial plane, although the orbits are still
stable in the radial direction. Then for the large spin case ($S < \sim O(1)),
the innermost stable circular orbit (ISCO) appears before the minimum of the
effective potential in the equatorial plane disappears. This changes the radius
of ISCO and then the frequency of the last circular orbit.Comment: 25 pages including 8 figure
A pragmatic cluster randomized controlled trial of an educational intervention for GPs in the assessment and management of depression
Background. General practitioners (GPs) can be provided with effective training in the skills to manage depression. However, it remains uncertain whether such training achieves health gain for their patients.
Method. The study aimed to measure the health gain from training GPs in skills for the assessment and management of depression. The study design was a cluster randomized controlled trial. GP participants were assessed for recognition of psychological disorders, attitudes to depression, prescribing patterns and experience of psychiatry and communication skills training. They were then randomized to receive training at baseline or the end of the study. Patients selected by GPs were assessed at baseline, 3 and 12 months. The primary outcome was depression status, measured by HAM-D. Secondary outcomes were psychiatric symptoms (GHQ-12) quality of life (SF-36), satisfaction with consultations, and health service use and costs.
Results. Thirty-eight GPs were recruited and 36 (95%) completed the study. They selected 318 patients, of whom 189 (59%) were successfully recruited. At 3 months there were no significant differences between intervention and control patients on HAM-D, GHQ-12 or SF-36. At 12 months there was a positive training effect in two domains of the SF-36, but no differences in HAM-D, GHQ-12 or health care costs. Patients reported trained GPs as somewhat better at listening and understanding but not in the other aspects of satisfaction.
Conclusions. Although training programmes may improve GPs' skills in managing depression, this does not appear to translate into health gain for depressed patients or the health service
Quantitative analysis of the effects queuing has on a CCID3 controlled DCCP flow
While the Data Congestion Control Protocol (DCCP) shows much promise at becoming a protocol of choice for real-time applications in the future, there are relatively speaking, only a small number of academic papers purporting to its performance and its various nuances. This paper will describe the effects queuing and in particular queue sizes have on DCCP when CCID3 is selected as the congestion control mechanism. From results obtained through the experimentation described in this paper, a clear trade-off between packet loss rates and packet latency values was found to occur when different queue sizes were employed on the experimental network. It was found that employing small fixed sized queues on the network led to lower packet latencies but higher volumes of packet loss as a result of the queue size reaching its maximum threshold more frequently. Alternatively when large queue sizes were used, the number of packet loss events reduced significantly however, packet latency values increased. In addition to showing this impending trade-off empirically, this paper describes ways in which this phenomenon could potentially be exploited to allow DCCP to offer applications with a more tailored form of transportation protocol based on their particular needs
Multiwalled CarbonNanotube/Polysulfone Composites
The solution method was used to create polysulfone/carbon nanotubes composites. The effect of three solvents (NMP, DMF, and THF), treatments (nitric acid and ethanol) and surfactants (ODA and OCA) on CNT/ solvent stability was investigated. NMP and DMF resulted in improved stability compared to THF, and all CNT treatments improved stability. Four composites were produced with CNT loadings of 0—5 wt%: as-received CNT and nitric acid treated in THF, as-received CNT and OCA surfactant CNT in NMP. Optical, TEM, and electrical percolation measurements confirmed the role of CNT/solvent stability on the final composite dispersion. Tensile testing and thermal analysis confirmed the presence of residual solvent in all samples. </jats:p
- …