197 research outputs found
Overtime and Short-time with Fluctuating Absenteeism and Demand
Even though overtime is a widely observed phenomenon, this paper argues against the view of overtime as a structural cost minimizing labour demand solution. A large part of the observed overtime can be explained by the volatility of demand and absenteeism.The paper''s main contribution is to investigate how stochastic absenteeism and stochastic demand tend to increase average hours per worker. Two distinct mechanisms are identified, independent of the type of uncertainty. The relative sizes of these mechanisms differ between the type of uncertainty, but also between cost minimization and profit maximization models. The profit maximization model has the advantage that it predicts a spike at normal hours.labour economics ;
Public transportation in UK viewed as a complex network
In this paper we investigate the topological and spatial features of public
transport networks (PTN) within the UK. Networks investigated include London,
Manchester, West Midlands, Bristol, national rail and coach networks during
2011. Using methods in complex network theory and statistical physics we are
able to discriminate PTNs with respect to their stability; which is the first
of this kind for national networks. Moreover, taking advantage of various
fractal properties we gain useful insights into the serviceable area of
stations. These features can be employed as key performance indicators in aid
of further developing efficient and stable PTNs.Comment: 23 pages, 9 figure
Adjuvancy and reactogenicity of N-acetylglycosaminyl-N-acetylmuramyl-dipeptide (GMDP) orally administered just prior to trivalent influenza subunit vaccine. A double-blind placebo-controlled study in nursing home residents.
One hundred and fifty-three nursing home residents received 0, 5, 25 or 50 mg N-acetylglucosaminyl-N-acetylmuramyl-dipeptide (GMDP) orally, and trivalent influenza subunit vaccine intramuscularly. One day after intervention, there was a strong increase of total leucocytes, monocytes and neutrophils in the groups receiving 25 or 50 mg GMDP. A GMDP dose dependent increase in systemic, but not in local, vaccine side-effects was observed. No significant differences in post-vaccination haemagglutination inhibiting serum antibody titres were observed between the four groups, indicating that oral administration of GMDP together with influenza vaccination, does not lead to a higher vaccine efficacy
Household survey evidence on domestic workers in Ethiopia
Whilst much scholarly attention of this nascent field of domestic service work focuses on protecting the rights and security of foreign/migrant domestic workers, the nature of domestic service work undertaken within national borders has escaped the attention of both researchers and public policy makers. Outlining the findings from a large household survey data in Ethiopia collected from seven major urban areas covering the period from 1994 to 2004, this paper departs from the usual focus on rights-based perspective and foreign migrant domestic service workers. Instead, the paper attempts to contribute to our understanding of the profile of domestic service providers, the significant drivers of participation in the provision of domestic services and the welfare of unpaid and paid domestic service workers in Ethiopia. In doing so, the paper contributes to the development of a greater evidence base, relevant for both researchers and public policy practitioners alike
Network analysis of the COSMOS galaxy field
The galaxy data provided by COSMOS survey for 1 by 1 degree field of sky are
analysed by methods of complex networks. Three galaxy samples (slices) with
redshifts ranging within intervals 0.88-0.91, 0.91-0.94 and 0.94-0.97 are
studied as two-dimensional projections for the spatial distributions of
galaxies. We construct networks and calculate network measures for each sample,
in order to analyse the network similarity of different samples, distinguish
various topological environments, and find associations between galaxy
properties (colour index and stellar mass) and their topological environments.
Results indicate a high level of similarity between geometry and topology for
different galaxy samples and no clear evidence of evolutionary trends in
network measures. The distribution of local clustering coefficient C manifests
three modes which allow for discrimination between stand-alone singlets and
dumbbells (0 <= C <= 0.1), intermediately (0 < C < 0.9) and clique (0.9 <= C <=
1) like galaxies. Analysing astrophysical properties of galaxies (colour index
and stellar masses), we show that distributions are similar in all slices,
however weak evolutionary trends can also be seen across redshift slices. To
specify different topological environments we have extracted selections of
galaxies from each sample according to different modes of C distribution. We
have found statistically significant associations between evolutionary
parameters of galaxies and selections of C: the distribution of stellar mass
for galaxies with interim C differ from the corresponding distributions for
stand-alone and clique galaxies, and this difference holds for all redshift
slices. The colour index realises somewhat different behaviour.Comment: 12 pages, 8 figures, accepted for publication in Monthly Notices of
the Royal Astronomical Societ
Management system for optimizing public transport networks: GPS record
As cities continue to grow in size and population, the design of public transport networks becomes complicated, given the wide diversity in the origins and destinations of users [1], as well as the saturation of vehicle infrastructure in large cities despite their attempts to adapt it according to population distribution. This indicates that, in order to reduce users’ travel time, it is necessary to implement alternative road solutions to the use of cars, increasing investment in public transportation [2, 3] by conducting a comprehensive analysis of the state of transportation. This situation has made appear the solutions and development oriented to transportation based on Internet of Things (IoT) which allows, in a first stage, monitoring of public transport systems, in order to optimize the deployment of transport units and thus reduce the time of transfer of users through the cities [4]. These solution proposals are focused on information collected from user resources (data collected through smart phones) to create a common database [5]. The present study proposes the development of an intelligent monitoring and management system for public transportation networks using a hybrid communication architecture based on wireless node networks using IPv6 and cellular networks (LTE, LTE-M)
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