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排序方式: 共有681条查询结果,搜索用时 15 毫秒
1.
Daniel Biedermann Jan Schneider Hendrik Drachsler 《Journal of Computer Assisted Learning》2021,37(5):1217-1231
Digital distractions can interfere with goal attainment and lead to undesirable habits that are hard to get red rid of. Various digital self-control interventions promise support to alleviate the negative impact of digital distractions. These interventions use different approaches, such as the blocking of apps and websites, goal setting, or visualizations of device usage statistics. While many apps and browser extensions make use of these features, little is known about their effectiveness. This systematic review synthesizes the current research to provide insights into the effectiveness of the different kinds of interventions. From a search of the ‘ACM’, ‘Springer Link’, ‘Web of Science’, ’IEEE Xplore’ and ‘Pubmed’ databases, we identified 28 digital self-control interventions. We categorized these interventions according to their features and their outcomes. The interventions showed varying degrees of effectiveness, and especially interventions that relied purely on increasing the participants' awareness were barely effective. For those interventions that sanctioned the use of distractions, the current literature indicates that the sanctions have to be sufficiently difficult to overcome, as they will otherwise be quickly dismissed. The overall confidence in the results is low, with small sample sizes, short study duration, and unclear study contexts. From these insights, we highlight research gaps and close with suggestions for future research. 相似文献
2.
Igboamalu Frank Nonso Ndjiongue Alain Richard Ferreira Hendrik Christoffel 《Telecommunication Systems》2020,73(4):521-530
Telecommunication Systems - Signals from indoor access points in a wireless fidelity suffer from high attenuation as a result of the thick walls and metal structures in the multilevel-storey... 相似文献
3.
An interregional labour market model incorporating vacancy chains and social security 总被引:1,自引:0,他引:1
This paper deals with three aspects of interregional demo-economic models which are important with respect to the analysis of regional labour market developments. First, attention is paid to forecasts of the exogenous regional variables, such as investments, exports, etc. Because data at the regional level are usually scarce, it is suggested to make these projections by means of a top-down model. Second, the social security sector is incorporated in the model framework, because changes in social security benefits, which are common in many Western countries nowaday, usually have substantial impacts on regional economic and demographic structures. Third, a vacancy chain model instead of a simple employment growth equation is tied to the standard demo-economic model framework. In this way not only employment growth but also migration, job mobility and related income effects can be taken into account. 相似文献
4.
Measuring knowledge transfer between fields of science 总被引:4,自引:2,他引:2
Rinia Ed J. van Leeuwen Thed N. Bruins Eppo E. W. van Vuren Hendrik G. van Raan Anthony F. J. 《Scientometrics》2002,54(3):347-362
In this paper we report on the results of an exploratory study of knowledge exchange between disciplines and subfields of
science, based on bibliometric methods. The goal of this analysis is twofold. Firstly, we consider knowledge exchange between
disciplines at a global level, by analysing cross-disciplinary citations in journal articles, based on the world publication
output in 1999. Among others a central position of the Basic Life Sciences within the Life Sciences and of Physics within
the Exact Sciences is shown. Limitations of analyses of interdisciplinary impact at the journal level are discussed. A second
topic is a discussion of measures which may be used to quantify the rate of knowledge transfer between fields and the importance
of work in a given field or for other disciplines. Two measures are applied, which appear to be proper indicators of impact
of research on other fields. These indicators of interdisciplinary impact may be applied at other institutional levels as
well.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
5.
We describe a formal language/notation for DNA molecules that may contain nicks and gaps. The elements of the language, DNA
expressions, denote formal DNA molecules. Different DNA expressions may denote the same formal DNA molecule. We analyse the
shortest DNA expressions denoting a given formal DNA molecule. We determine lower bounds on their lengths and explain how
we construct these minimal DNA expressions. 相似文献
6.
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8.
Rogier Schonenborg Adalberto Costessi Peter Schiller 《Microgravity science and technology》2007,19(5-6):219-224
This paper gives a quick overview of how various scientific, operational and safety related requirements drove the development of hardware for the Bone Proteomics (BOP) experiment that was conducted on the International Space Station during the Italian Soyuz Mission in 2005. The experiment objectives will be highlighted briefly and design solutions will be presented. Comments will be given regarding the choice of a particular design solution and the impact on the complexity, cost and development time. Conclusions in this paper are based on the experience gained when developing the BOP experiment hardware and other relatively small experiment hardware packages, typical of European Soyuz Missions. The observations should not be extrapolated to large payloads. The objective of this paper is not to produce a recipe for developing experiment hardware; dedicated documents for that purpose are available elsewhere. Rather, the objective is to help others profit from experience gained in the development of relatively small experiment hardware packages, and to highlight where time and cost saving decisions can be made. 相似文献
9.
Which signals are important in gaining attention in science? For a group of 1,371 scientific articles published in 17 demography
journals in the years 1990-1992 we track their influence and discern which signals are important in receiving citations. Three
types of signals are examined: the author's reputation (as producer of the idea), the journal (as the broker of the idea),
and the state of uncitedness (as an indication of the assessment by the scientific community of an idea). The empirical analysis
points out that, first, the reputation of journals plays an overriding role in gaining attention in science. Second, in contrast
to common wisdom, the state of uncitedness does not affect the future probability of being cited. And third, the reputation
of a journal may help to get late recognition (so-called sleeping beauties) as well as generate 'flash-in-the-pans': immediately
noted articles but apparently not very influential in the long run. 相似文献
10.
A new formalism based on perfectly matched layers (PMLs) is presented to derive new series expansions for the Green's function of an infinite set of point sources with a 1-D periodicity embedded in a layered medium. Several PML-based series expansions, both in the spatial and spectral domains, combined with suitable convergence acceleration techniques such as the Shanks transform and Ewald transform, are proposed and their efficiency is evaluated. For each pair of excitation and observation locations, an optimal series expansion in terms of accuracy and CPU time is proposed, resulting in a significant speed-up compared to existing approaches. 相似文献