19 research outputs found
Сбор материалов из социальных сетей как институциональная задача: опыт Библиотеки Конгресса США
No full textSocial media has become a valuable tool that has helped connect, facilitate, discover, and encourage the use of the Library of Congress’s collections and content. The Library has cultivated trust and approachability as both a collector and user of social media. The Library of Congress has been using social media both as a collector and a user to execute its mission. Authors describe the use of social media in both of these roles beginning with the Library as a collector. The vision, as stated in the Library’s strategic plan, is that all Americans are connected to the Library. Different channels of social media have allowed the Library to extend that connection into discovery and use of the Library’s vast online collections and engage audiences in ways that are more approachable and immediate. As a result, the institution is more accessible than ever before.В последние годы возросла роль социальных сетей как эффективного средства для установления связей, организации деятельности, раскрытия информации, а также стимулирования использования коллекций и услуг Библиотеки Конгресса США (The Library of Congress, БК). Библиотека повышает свой уровень надежности и доступности не только как учреждение, ответственное за сбор материалов из социальных сетей, но и как непосредственный пользователь сетями. БК накопила большой опыт работы с социальными сетями как для сбора материала, так и для взаимодействия с пользователями. В данной статье авторы рассказывают об использовании социальных сетей в обоих случаях, начиная с роли БК как собирателя материала. Согласно плану стратегического развития, БК стремится установить линию связи с каждым американцем. Социальные сети позволили расширить эту связь, раскрыть информацию об ее обширных коллекциях электронных ресурсов, а также привлечь широкую публику более доступными и быстрыми способами с помощью различных каналов социальных сетей. Благодаря этому БК теперь стала доступнее, чем когда-либо прежде
Matching hydraulics and ecology in water systems
No full textStarosolsky, Ö. - Introduction Hjorth, P., Kobus, H., Nachtnebel, H.P., Nottage, A. Robarts, R. - Relating hydraulicts and ecological processes Bogardi, I., Saeijs, H.L.F., Vrijling, J.K. - Involvement of ecology in decision process Saeijs, H.L., Van der Zwaard, J.J. The subsystem Rivers Bogardi, Il, Hjorth, P. Robarts, R, - The susbsystem Lakes Knoester, M., Nottage, A., Roelfzema, A. - The subsystem Estuaries Herrmann, R., Hubert, P., Kobus, H. - The subsystem Groundwater Benedini, M., Bogardi, I, Dick, T.M., Korf, W. - The uncompromising involvement of ecology Conclusions Lindh, G. - An annotated bibliography on case studies Literature Vocabulary of aquatic ecosystem
Living an a 'drain'
No full textWorkshop 1. Session 1.3: (Counter)acting stigma. Summary: The usual characterisations of multi-ethnic neighbourhoods in Dutch cities are rather humiliating and reinforce the negative image of these neighbourhoods. The Rotterdam invention \u91drain\u92 (afvalputje) is a very dirty example, but the current label \u91disadvantaged neighbourhood\u92 (achterstandsbuurt) equally does not improve their reputation. The impact of this negative labeling is far-reaching. Not only does the reputation of a neighbourhood effect the reputation of the residents, it also influences their perception of their environment and neighbours. The precise effects of a negative reputation on the (self)images of the residents depends on their housing history, their social-economical possibilities, their future plans and the availability of alternative sources of appreciation and acknowledgment. The overall effects are distance and prejudices between different groups of the population and hesitations to concern oneself with neigbourhood-affaires
Learning from safety in other industries
No full textThe Dutch building industry has been shocked by some major structural accidents during the last 10 years with buildings during construction as well as with delivered buildings. Several initiatives were started to improve the safety. In other industries the safety awareness seemed to be more developed. In this article the Dutch building sector is compared with the aviation industry and(chemical) process industry, to see which safety influencing factors can be improved for the building industry. It appears that the risks in relation to a building after completion are fairly low, comparable to the other industries. On the other hand the approach towards safety in the building industry is relatively undeveloped, which gives starting points for improvement.Author ManuscriptSteel & Composite Structure
The influence of a dynamic solar shape on tests of gravitational theory using observations of Mercury missions
No full textTests of General Relativity are often done in the Solar System by using tracking data from interplanetary space missions, to measure the perturbation on the orbits of the planets that is predicted by General Relativity. The next best opportunity for such a test is the BepiColombo spacecraft by the European Space Agency, which will arrive at Mercury in late 2025. However, a very similar perturbation is also produced by the gravitational oblateness of the Sun through the zonal coefficient J2. The exact value of this coefficient has been hard to determine despite centuries of observations of the solar shape, and besides the accuracy of the tracking data it is the main source of uncertainty for the tests of gravitational theory. Recent publications in heliophysics suggest that higher order effects might also be of relevant influence too, such as coefficient J2 being dynamic along the solar cycle, or the fourth zonal coefficient J4. This thesis project attempts to bring together two fields of research: the field that tries to test General Relativity (GR) in the Solar System, and the field of heliophysics that tries to unravel the structure of the Sun. The orbit of Mercury, as well as the observations of BepiColombo and it predecessor MESSENGER, are simulated in a virtual reality where settings of the solar shape are varied. Relevant parameters to tests of gravity are then estimated using a least-squares algorithm and their error is analysed. It is found that the amplitude of a periodic component of the solar oblateness can be found with an uncertainty of 0.02% of the value of J2. It is also found that if a periodic component exists with an amplitude higher than 1%, it can lead to errors in the experiments of GR to the point that results oppose the theory of General Relativity. Expected values for J4 from heliophysics currently do not influence the orbit of Mercury by a measurable amount. Based on this work, it is recommended to those in the field who test General Relativity using data from BepiColombo, to take this effect into consideration to prevent getting results in their experiments that can lead physicists in the wrong direction concerning the development of gravitational theory.Aerospace Engineerin
Het prijzen van Bitcoin-opties met behulp van sprong-diffusie processen
No full textApplied mathematicsElectrical Engineering, Mathematics and Computer Scienc
The Influence of Dynamic Solar Oblateness on Tracking Data Analysis from Past and Future Mercury Missions
No full textWhen the BepiColombo spacecraft arrives at Mercury in late 2025, it will be able to measure the orbit of the planet with unprecedented accuracy, allowing for more accurate measurements of the perihelion advance of the planet, as predicted by the Theory of General Relativity (GR). A similar effect is produced by the gravitational oblateness of the Sun through the zonal coefficient (Formula presented.). The gravitational field of the Sun has been hard to determine despite centuries of observations, causing great uncertainties in experiments on GR. Recent publications in heliophysics suggest that (Formula presented.) is not a constant, but a dynamic value that varies with solar magnetic activity. The aim of this paper is to analyse what the effect is of suggested higher-order effects of the solar gravitational field on experiments of the perihelion advance of Mercury as predicted by GR. The orbit of Mercury and observations of the MESSENGER and BepiColombo spacecraft are simulated, and parameters corresponding to gravitational theory, as well as the oblateness (Formula presented.) including a time-variable component are estimated using a least-squares approach. The result of the estimation is that the amplitude of a periodic component can be found with an uncertainty of (Formula presented.), equal to 0.017% the value of (Formula presented.). From analysis of published experiments that used MESSENGER tracking data, it can already be deduced that the amplitude of the periodic variation cannot be higher than 5% of the value of (Formula presented.). It is also found that if a periodic component exists with an amplitude greater than 0.04% the value of (Formula presented.) and it is not considered, it can lead to errors in the experiments of GR using BepiColombo data to the point that results falsely confirm or contradict the Theory of General Relativity.Space Systems EgineeringAstrodynamics & Space Mission
