30,737 research outputs found
An integrated operational system to reduce O&M cost of offshore wind farms
No full textOffshore wind is a relatively new industry and it is generally more expensive to generate electricity than many alternative renewable sources. Operation & Maintenance (O&M) makes up a significant part of the overall cost of running Offshore Wind Turbines (OWT). Since the O&M associated responsibility is shared among turbine manufacturers, wind farm operators and the offshore transmission owners, this has inevitably led to lack of information, duplication of effort and less efficiency. Big data analytics is one great technique that will drive future growth. In this paper, an integrated operational system of offshore wind farm is proposed deploying big data analytics. Firstly, the current state of the O&M of offshore wind farm and the big data analytics are introduced. Afterwards, a predictive maintenance model and a maintenance implementation model are proposed, and an integrated operational system is developed incorporating those two models in order to optimize maintenance planning and implementation. Finally, the possible contribution of such a system to a more effective O&M of offshore wind farm is discussed.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Transport Engineering and Logistic
Exploring the experiences of rehabilitated stroke survivors and the perceptions of stakeholders with regard to stroke survivors returning to work in South-West Nigeria
No full textMagister Scientiae (Occupational Therapy) - MSc(OT)Stroke has been identified as a global cause of neurological disability with a resultant burden shared not only by the survivor but also by the society. The resumption of one’s role as a worker after having a stroke is an important rehabilitation goal. South-West, Nigeria has experienced high incidence and prevalence of stroke leaving a quarter of survivors with severe disability and difficulty in community integration after rehabilitation. As a disability resulting from a stroke could be viewed as being a dynamic interaction between the health condition and contextual factors, a client-centred approach should be focal to stroke management to facilitate return to work. Therefore, it became necessary to explore the return to work process from stroke survivors and stakeholder’s perspective in order to understand the challenges stroke survivors face while adapting to their worker roles, to improve service design and delivery as well as to facilitate the return to work after having a stroke. The study was aimed at exploring and describing the experiences of rehabilitated stroke survivors and perceptions of stakeholders about stroke survivors returning to work in South-West Nigeria. A qualitative research design was used to explore these experiences and perceptions from nineteen participants that comprised of nine stroke survivors, two key informants (rehabilitation specialists) and eight caregivers of the respective stroke survivor. Two methods of data collection were used by the researcher to access the perceptions and experiences of the participants. The researcher made use of focus groups with the caregivers while in-depth interviews were conducted with the stroke survivors and rehabilitation specialists. One pilot testing in-depth interview and eleven in-depth interviews were conducted with the stroke survivors and rehabilitation specialists while two focus group discussions were held with the eight caregivers consisting of four participants per group. The data from the study was analysed using thematic analysis. All data were managed manually. The study was further aimed at obtaining participants` perceptions and experiences of barriers and facilitators as well as adaptation processes that influenced the stroke survivors’ ability to resume their worker role. The findings were revealed in five themes. Theme one and two describes the barriers experienced by the stroke survivors while returning to work in the form of loss of former self and returning to work is a struggle. The resumption of the previous worker role by the stroke survivors was construed to be a contest which entails a struggle between the survivor, survivor’s job characteristics, rehabilitation intervention and stigma from the society. Poor access to rehabilitation interventions, inadequacy of treatment and poor insight of the stroke survivor regarding condition, job characteristics as well as social stigma related to the condition were observed as factors that posed great challenges to the participants. Theme three describes the factors that facilitated the resumption of the worker role for the stroke survivors. Engagement in rehabilitation as well as social support enabled the stroke survivors to overcome the barriers and returning to work. Theme four describes the adaptation strategies that enable the return to work for the stroke survivors. Theme four was described by an intrinsic adaptation process that involves the acceptance of the illness and being motivated to return to work and an extrinsic adaptation process that involves gradual work exposure, workplace and home adaptation. Theme five describes the participants’ perception of changes needed in the rehabilitation services and policies that would facilitate the quick return to work of the stroke survivor. Promoting participation of stroke survivors in work through government policies was observed to be a necessary recommendation for the study. These were seen to be achievable through the improvement of rehabilitation resources, enabling access to rehabilitation through financial assistance, change of the regulatory environment to accommodate for the disabled and the initiation of health promotion through public awareness campaigns in the community regarding stroke. The Person Environment Occupation model of occupational performance was used as a framework to interpret the findings of the study; the barriers, facilitators and adaptation process was placed into perspectives as they impacted on the experience of the stroke survivors ‘resumption of their worker role. The resumption of the worker role of the stroke survivors was observed not only to be influenced by the individual characteristics of the survivors but also by the environmental context within which the return to work process took place
Exploring the experiences of rehabilitated stroke survivors and the perceptions of stakeholders with regard to stroke survivors returning to work in South-West Nigeria
No full textMagister Scientiae (Occupational Therapy) - MSc(OT)Stroke has been identified as a global cause of neurological disability with a resultant burden shared not only by the survivor but also by the society. The resumption of one’s role as a worker after having a stroke is an important rehabilitation goal. South-West, Nigeria has experienced high incidence and prevalence of stroke leaving a quarter of survivors with severe disability and difficulty in community integration after rehabilitation. As a disability resulting from a stroke could be viewed as being a dynamic interaction between the health condition and contextual factors, a client-centred approach should be focal to stroke management to facilitate return to work. Therefore, it became necessary to explore the return to work process from stroke survivors and stakeholder’s perspective in order to understand the challenges stroke survivors face while adapting to their worker roles, to improve service design and delivery as well as to facilitate the return to work after having a stroke. The study was aimed at exploring and describing the experiences of rehabilitated stroke survivors and perceptions of stakeholders about stroke survivors returning to work in South-West Nigeria. A qualitative research design was used to explore these experiences and perceptions from nineteen participants that comprised of nine stroke survivors, two key informants (rehabilitation specialists) and eight caregivers of the respective stroke survivor. Two methods of data collection were used by the researcher to access the perceptions and experiences of the participants. The researcher made use of focus groups with the caregivers while in-depth interviews were conducted with the stroke survivors and rehabilitation specialists. One pilot testing in-depth interview and eleven in-depth interviews were conducted with the stroke survivors and rehabilitation specialists while two focus group discussions were held with the eight caregivers consisting of four participants per group. The data from the study was analysed using thematic analysis. All data were managed manually. The study was further aimed at obtaining participants` perceptions and experiences of barriers and facilitators as well as adaptation processes that influenced the stroke survivors’ ability to resume their worker role. The findings were revealed in five themes. Theme one and two describes the barriers experienced by the stroke survivors while returning to work in the form of loss of former self and returning to work is a struggle. The resumption of the previous worker role by the stroke survivors was construed to be a contest which entails a struggle between the survivor, survivor’s job characteristics, rehabilitation intervention and stigma from the society. Poor access to rehabilitation interventions, inadequacy of treatment and poor insight of the stroke survivor regarding condition, job characteristics as well as social stigma related to the condition were observed as factors that posed great challenges to the participants. Theme three describes the factors that facilitated the resumption of the worker role for the stroke survivors. Engagement in rehabilitation as well as social support enabled the stroke survivors to overcome the barriers and returning to work. Theme four describes the adaptation strategies that enable the return to work for the stroke survivors. Theme four was described by an intrinsic adaptation process that involves the acceptance of the illness and being motivated to return to work and an extrinsic adaptation process that involves gradual work exposure, workplace and home adaptation. Theme five describes the participants’ perception of changes needed in the rehabilitation services and policies that would facilitate the quick return to work of the stroke survivor. Promoting participation of stroke survivors in work through government policies was observed to be a necessary recommendation for the study. These were seen to be achievable through the improvement of rehabilitation resources, enabling access to rehabilitation through financial assistance, change of the regulatory environment to accommodate for the disabled and the initiation of health promotion through public awareness campaigns in the community regarding stroke. The Person Environment Occupation model of occupational performance was used as a framework to interpret the findings of the study; the barriers, facilitators and adaptation process was placed into perspectives as they impacted on the experience of the stroke survivors ‘resumption of their worker role. The resumption of the worker role of the stroke survivors was observed not only to be influenced by the individual characteristics of the survivors but also by the environmental context within which the return to work process took place
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
The long-wavelength view of GG Tau A: rocks in the ring world
No full textWe present the first detection of GG Tau A at centimetre wavelengths, made with the Arcminute Microkelvin Imager Large Array at a frequency of 16 GHz (λ = 1.8 cm). The source is detected at >6 σrms with an integrated flux density of S16GHz = 249 ± 45 µJy. We use these new centimetre-wave data, in conjunction with additional measurements compiled from the literature, to investigate the long-wavelength tail of the dust emission from this unusual protoplanetary system. We use an MCMC-based method to determine maximum likelihood parameters for a simple parametric spectral model and consider the opacity and mass of the dust contributing to the microwave emission. We derive a dust mass of Md ~ 0.1 Msun, constrain the dimensions of the emitting region and find that the opacity index at λ > 7 mm is less than unity, implying a contribution to the dust population from grains exceeding ~4 cm in size. We suggest that this indicates coagulation within the GG Tau A system has proceeded to the point where dust grains have grown to the size of small rocks with dimensions of a few centimetres. Considering the relatively young age of the GG Tau association in combination with the low derived disc mass, we suggest that this system may provide a useful test case for rapid core accretion planet formation models
DNS of turbulent mixing layers with variable density
No full textWe present some preliminary results of direct numerical simulations of three-dimensional, temporal, plane mixing layers with variable density. The simulations are run with a parallel in-house code that solves the Navier-Stokes equations in the Low-Mach number approximation, using a novel algorithm based on an extended version of the velocity-vorticity formulation used by Kim, Moin & Moser (1987) for incompressible flows. The simulations are run with Pr=0.7 and achieve Re_lambda=90-110 during the self-similar evolution of the mixing layer. Four cases with density ratios s=1,2,4 and 8 are presented. Our results show good agreement with previous experimental and numerical studies, and allow us to characterize the scales in the temperature spectra
Stability in m-quota games
No full textThe abstracts (in two languages) can be found in the pdf file of the article.
Original author name(s) and title in Russian and Lithuanian:
О. Н. Бондарева, Устойчивость в играх с m-квотой
O. Bondareva, Stabilumas lošimuose su m-kvot
Kevin M. O\u27Connell
No full textKevin M. O’Connell is the Director of the Office of Space Commerce at the U.S. Department of Commerce. Within this position, Mr. O’Connell leads an office with responsibility as a space industry advocate within the Executive Branch of the U.S. government. Mr. O’Connell brings over 35 years of experience in the U.S. government, in research organizations, and as an entrepreneur and business leader to this position.
Mr. O’Connell has researched and written extensively on the policy, security, and global market issues related to commercialization of remote sensing. Aside from numerous articles and op-eds, he was co-author of Commercial Observation Satellites: at the Leading Edge of Global Transparency (2000). He served as the Executive Secretary and Staff Director of the NIMA Commission (1999-2000). He was a member, and later Chair, of NOAA’s federal advisory committee on remote sensing from 2002-2016.
Previously, Mr. O’Connell served as the CEO of Innovative Analytics and Training, a Washington, D.C. professional services firm focused on analysis and decision support for U.S. government and commercial clients. Among other issues, the firm focused on market trends and anticipatory/futures analysis for high-technology industries such as cyber, cloud computing, and geospatial technologies. During this time, he also served as a senior consultant to the Office of the Director of National Intelligence and as an independent advisor to the Director, National Geospatial Intelligence Agency.
Mr. O’Connell’s background also includes extensive experience in national security and intelligence matters, including assignments in the Department of Defense, Department of State, National Security Council, and the Office of the Vice President. He spent a decade conducting and managing research in these areas at the RAND Corporation, including as the first director of RAND’s Intelligence Policy Center.
Finally, Mr. O’Connell has taught a long-running course on comparative intelligence in Georgetown University’s School of Foreign Service, Security Studies Program.https://commons.erau.edu/stm-images/1119/thumbnail.jp
Mining e-mail content for author identification forensics
No full textWe describe an investigation into e-mail content mining for author identification, or authorship attribution, for the purpose of forensic investigation. We focus our discussion on the ability to discriminate between authors for the case of both aggregated e-mail topics as well as across different email topics. An extended set of e-mail document features including structural characteristics and linguistic patterns were derived and, together with a Support Vector Machine learning algorithm, were used for mining the e-mail content. Experiments using a number of e-mail documents generated by different authors on a set of topics gave promising results for both aggregated and multi-topic author categorisation
Self-archiving practice and the influence of publisher policies in the social sciences
No full textAuthors in different disciplines exhibit very different behaviours on the so-called ‘green’ road to open access, i.e. self-archiving. This study looks at the self-archiving behaviour of authors publishing in leading journals in six social science disciplines. It tests the hypothesis that authors are self-archiving according to the norms of their respective disciplines rather than following self-archiving policies of publishers, and that, as a result, they are self-archiving significant numbers of publisher PDF versions. It finds significant levels of
self-archiving, as well as significant self-archiving of
the publisher PDF version, in all the disciplines
investigated. Publishers’ self-archiving policies have
no influence on author self-archiving practice
- …
