726 research outputs found
Tele-operated climbing and mobile service robots for remote inspection and maintenance in nuclear industry
No full textNew (Probabilistic) Derivation of Diaz-Metcalf and Pólya-Szegő Inequalities and Consequences
No full textClassical inequalities of Diaz - Metcalf and Pólya - Szegő are generalized to
probabilistic setting which covers the initial deterministic (both discrete and integral) variants.
From these two inequalities, by the probabilistic derivation method further well -
known inequalities are obtained (that ones by Kantorovich, Rennie and Schweitzer)
Onset Detection through Maximal Redundancy Detection
No full textWe propose a criterion, called ‘maximal redundancy’, for onset detection in time series. The concept redundancy is adopted from information theory and indicates how well a signal locally can be explained by an underlying model. It is shown that a local maximum in the redundancy is a good indicator for an onset. It is proven that ‘maximal redundancy’ detection is a statistical asymptotically optimal detector for AR processes. It also accounts for potentially non-Gaussian time series and non-Gaussian innovations in the AR processes. Several applications are shown where the new criterion has been successfully applied.sponsorship: This work was supported by the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT Vlaanderen).
The second author is funded by the Belgian Fund for Research -- Flanders (G.0248.03, G.0234.04).status: Publishe
The Benefits of Being Economics Professor A (and not Z)
Get PDFAlphabetic name ordering on multi-authored academic papers, which is the convention in the economics discipline and various other disciplines, is to the advantage of people whose last name initials are placed early in the alphabet. As it turns out, Professor A, who has been a first author more often than Professor Z, will have published more articles and experienced afaster growth rate over the course of her career as a result of reputation and visibility. Moreover, authors know that name ordering matters and indeed take ordering seriously: Several characteristics of an author group composition determine the decision to deviate from the default alphabetic name order to a significant extent.performance measurement, incentives, economists, name ordering
The Country-Product-Dummy Method: A Stochastic Approach to the Computation of Purchasing Power Parities in the ICP
Get PDFA paper for presentation at the SSHRC Conference on Index Numbers and Productivity Measurement to be held during 30 June � 3 July, 2004 in Vancouver. The author wishes to thank Bettina Aten, Erwin Diewert, Alan Heston, Chris O�Donnell and Marcel Timmer for helpful discussions on the subject matter of this paper.
The role of mud on the long-term morphological development of a tidal basin
No full textCivil Engineering and GeosciencesHydraulic EngineeringCivil Engineerin
Periodieke controle op prostaatkanker: Doen of niet doen?
No full textDoor het ErasmusMC in Rotterdam is een prostaatkanker-dataset beschikbaar gesteld. De onderzoeksvraag bij deze dataset is "Is het relevant om te controleren op prostaatkanker bij mannen tussen de 54 jaar en 75 jaar". Om deze vraag te beantwoorden is gebruik gemaakt van verschillende analyses. Bovendien zijn twee datasets gesimuleerd. Survivalanalyse is een methode om te analyseren hoe lang het duurt tot een gebeurtenis plaatsvindt. In de geneeskunde is dit een vaak gebruikte analyse. Survivalanalyse wordt vaak toegepast op data waarvan alleen bekend is dat tot het einde van het onderzoek de gebeurtenis niet plaats gevonden heeft, dit heet rechts-gecensureerde data. Dat de gebeurtenis niet plaatsvindt tijdens het onderzoek kan meerdere oorzaken hebben. In de geneeskunde komt het vaak voor dat data rechts-gecensureerd is doordat een persoon overleden is door een andere gebeurtenis, waardoor de onderzochte gebeurtenis niet plaats kan vinden. Dit heet een competing risk. Standaard survivalanalyse gaat er vanuit dat het tijdstip van censuur onafhankelijk is van het tijdstip waarop de gebeurtenis plaatsvindt. Als de gebeurtenis niet plaatsvindt door het optreden van een competing risk, is deze aanname in het algemeen niet waar. In dit geval moet gebruik gemaakt worden van competing risk analyse. De twee competing risk modellen die het meest gebruikt worden zijn het oorzaak-specieke hazardmodel en het model van Fine en Gray. Voor de gesimuleerde datasets geldt dat bij dataset 1 de ene groep meer kans heeft op de beoogde gebeurtenis dan de andere groep. Bij dataset 2 zijn de kansen op gebeurtenissen gelijk. Na analyse van deze datasets volgt de conclusie dat als er verschil is in het aantal personen dat overlijdt aan de beoogde gebeurtenis, dit ook naar voren komt uit de resultaten. Voor de prostaatkanker-data geldt dat de competing risks de doodsoorzaak domineren. Daardoor komt uit een globale analyse een ander resultaat dan uit een meer nauwkeurige analyse. Uit meer nauwkeurige analyse volgt dat het relevant is om te controleren op prostaatkanker bij mannen tussen de 54 jaar en 75 jaar.Applied mathematicsElectrical Engineering, Mathematics and Computer Scienc
Commensality or Reverie in Eating? Exploring the Solo Dining Experience
No full textCommensality, the act of eating together, is commonly associated with many benefits. Dining solo, in contrast, is frequently connected to adverse effects on a person. There is a growing interest in human-computer interaction (HCI) and design in how innovations can enhance eating experiences by, for example, facilitating commensality. The steadily growing number of people eating alone and the associated risks beg the question of how HCI and design could contribute to and improve the solo dining experience and whether or not mimicking or facilitating commensality is what solo diners want. This two-phased study reports on the context exploration of the multimodal solitary dining experience. In the first phase, we scoped the literature describing the benefits and drawbacks of solo dining and commensality. For the second phase, a digital food diary was developed and completed by six solo diners to collect further insights and user requirements. Photos and annotations collected as part of the food diary were analyzed using content analysis. The results indicate several advantages of eating alone, including feeling relaxed, perceiving solo dining as a moment of self-pampering, and appreciating the cooking experience. Overall, it seems that solo dining is not merely a lack of commensality, but a unique experience in and of itself, where people seem to strive towards finding reverie in eating.Design Aesthetic
Maintenance dredging in the Port of Rotterdam: A research to the increase in maintenance dredging volume at Port of Rotterdam
No full textThe Port of Rotterdam (PoR), located in the Rhine-Meuse estuary, is subject to sedimentation. In order to keep the port accessible for vessels with high drafts, maintenance dredging works are done. The maintenance dredging over the port area is executed by two parties, PoR itself regarding the harbour basins and Rijkswaterstaat (RWS) regarding the river and waterways.Since 2013 a substantial increase of the yearly total maintenance dredging volume of the area under control of PoR is observed. The problem of this research is the increase in maintenance dredging volume, from an average of 5.2 mln cubic meters a year (over 2005-2012) to an average of 8.9 mln cubic meters a year (over 2013-2016). By analysis of the administrated maintenance dredging volumes database of PoR it is concluded that the problem is concentrated at Maasvlakte I. Including the maintenance dredging volumes data of RWS results in the conclusion that over the entire port area no occurrence of an increase in maintenance dredging volume is observed. A decrease administrated by RWS at the same period of time is concentrated at the area in front of Maasvlakte I, the harbour basin responsible for the increase in maintenance dredging volume of PoR. These findings lead to the conclusion that not an increase of sedimentation over the port area is responsible for the research problem, but a redistribution of the sedimentation rates from the area in front of Maasvlakte I to Maasvlakte I is. An analysis of the events that are potentially of influence on the research problem is performed. Based on the correlation of time and potential impact on the hydrodynamics of the water system, the event 'Construction of Maasvlakte II' is selected for an assessment. Two simulations with an extensive hydrodynamic flow model managed by PoR are run. One simulation includes the layout of the Maasvlakte before the construction of Maasvlakte II, the other includes the layout of the Maasvlakte as it is today. Both simulation use exactly the same initial and boundary conditions. With use of the simulations, the impact on the hydrodynamic conditions within the area of interest is assessed. The results show a significant increase of the tidal filling volume of the Maasvlakte harbour basins with a factor of 1.4. This increase is associated with in particular a significant increase of the horizontal flow velocities, and strengthened by a higher horizontal density gradient as a result of higher mixing rates of fresh and saline water at the Maasvlakte. The increase of the horizontal flow velocity is in particular measured in front of Maasvlakte I and in the connection to Maasvlakte I itself. Within the Maasvlakte harbour basin, the velocities are quickly dampened by the large width of the basin.The results of the assessment correspond accurately with the results of the data analysis. At the area subject to an increase of the horizontal flow velocity, a decrease of the maintenance dredging volume is observed. At the area where an increase in maintenance dredging volume is observed, no to slight changes of the flow velocity are measured. This is explained as follows. The increase of the tidal filling volume by the construction of Maasvlakte II, results in an increase of the horizontal velocities over the entire area connecting the North Sea to the Maasvlakte. Sediments that were able to settle within that connection before are now kept in suspension and transport to the Maasvlakte. The sediments kept in suspension reach the harbour basins where the horizontal flow velocities are quickly dampened by the large width of the basin, enabling the sediments to settle.It is concluded that the dominant mechanism leading to the increase in maintenance dredging volumes at the Port of Rotterdam is a change in local hydrodynamics by the construction of Maasvlakte II, resulting in a redistribution of the sedimentation rates within CaBe-system. A potential reduction measure in the form of a sediment trap is recommended to improve the current situation, but is unable to bring the hydrodynamics within system back to the situation as before the construction. The research problem is one of the consequences of the construction of Maasvlakte II, and hence partly have to accepted as well. A detailed study to the design of the problem specific sediment trap is required. Other studies that are recommended to improve the understanding of the actual problem regard the used dredging strategy, the exact pattern of sedimentation and the development of the composition of the bed material in the area the problem is concentrated.Civil Engineering | Hydraulic Engineerin
Prototyping tangible tools for sonic sketching in the UX design
No full textSound in UX design can be used in a variety of ways; to navigate the interaction, for branding, to set the ambience etc. The importance of sound for the user experience of a product is undeniable; however, this is not represented in the practices of UX designers. UX designers lack the tools and knowledge needed to integrate sound design into their prototyping activities. As a result, the sound is often considered last-moment, limiting the creative potential and added value of sound in the interaction. This report explores the possibilities of integrating sound design activities into the practices of UX designers. This is done through design research activities such as interviews, co-creation sessions, creating (interactive) prototypes and user testing. The aim of the project is to provide UX designers with prototyping tools for sound design. Common sound design tools are difficult to integrate in prototyping activities as UX designers often lack the skills and knowledge needed to operate these tools in a quick-paced and iterative way; which is needed in order to facilitate prototyping. Furthermore ways of bridging the semantic gap between the stakeholders is explored as well as the potential of tangible interfaces in making sound design more intuitive and engaging for UX designers. Finally, a concept is introduced: The Timbreworld, parts of which are embodied in an interactive prototype. The Timbreworld is a (tangible) interface for sonic sketching, it enables its users to create quick and iterative sound prototypes. The interactive prototype has been tested with participants and evaluated based on the design guidelines provided in the reportDesign for Interactio
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