1,279 research outputs found
Electrodynamics of an omega-band as deduced from optical and magnetometer data
We investigate an omega-band event that took place above northern Scandinavia
around 02:00–02:30 UT on 9 March 1999. In our analysis we use ground based
magnetometer, optical and riometer measurements together with satellite based
optical images. The optical and riometer data are used to estimate the
ionospheric Hall and Pedersen conductances, while ionospheric equivalent
currents are obtained from the magnetometer measurements. These data sets are
used as input in a local KRM calculation, which gives the ionospheric
potential electric field as output, thus giving us a complete picture of the
ionospheric electrodynamic state during the omega-band event.
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The overall structure of the electric field and field-aligned current (FAC)
provided by the local KRM method are in good agreement with previous studies.
Also the <I><B>E</B></I>×<I><B>B</B></I> drift velocity calculated from the local
KRM solution is in good qualitative agreement with the plasma velocity
measured by the Finnish CUTLASS radar, giving further support for the new
local KRM method. The high-resolution conductance estimates allow us to
discern the detailed structure of the omega-band current system. The highest
Hall and Pedersen conductances, ~50 and ~25 S, respectively, are
found at the edges of the bright auroral tongue. Inside the tongue,
conductances are somewhat smaller, but still significantly higher than
typical background values. The electric field shows a converging pattern
around the tongues, and the field strength drops from ~40 mV/m found at
optically dark regions to ~10 mV/m inside the areas of enhanced
conductivity. Downward FAC flow in the dark regions, while upward currents
flow inside the auroral tongue. Additionally, sharp conductance gradients at
the edge of an auroral tongue are associated with narrow strips of intense
FACs, so that a strip of downward current flows at the eastern (leading) edge
and a similar strip of upward current is present at the western (trailing)
edge. The Joule heating follows the electric field pattern, so that it is
diminished inside the bright auroral tongue
Competency and empowerment of project managers in China
The Agent Construction Management (ACM) system is one of the new measures adopted in government funded projects in China. The main characteristic of the ACM system is the introduction of an independent professional project management firm into the project management process. The ACM system is still in its trial stage in China and there is no unified qualification assessment system for agent construction organizations. While the importance of the project manager’s competence is recognized, previous research also shows that project manager’s empowerment is conducive to project performance. The definition of competency is confusing as several terms such as competency/competencies, competence/competences, capability and ability are used interchangeably and inconsistently. Competence is the state or quality of being adequately qualified -- the ability to perform a specific role (e.g. PMI’s project manager’s competency development framework). While empowerment can be viewed as a relational construct and considered within a more general concept of power, it is also a motivational (or psychological) construct. These two perspectives of empowerment are not independent and motivational empowerment may be an outcome of relational empowerment. This research aims to analyze the relationships of motivational empowerment and competency on job performance of the project managers in the ACM organisations. Regression modelling is adopted to analyze the data collected from 203 project managers involved in projects adopting ACM system. Findings support the relationships of competency and empowerment and their effect on project manager’s job performance.postprin
Procurement innovation: perspectives from Chinese international construction companies
The international construction business is witnessing a trend that companies deliver projects through the adoption of innovative procurement systems (e.g. Building Operate Transfer, Public Private Partnership). By devising innovative procurement systems, it is possible to realise construction projects that are difficult for traditional procurement methods, to develop competitive advantages for companies, and ultimately, to deliver value to the society. Notably, Chinese companies are making impressive inroads into the international construction market through enhancing their competitiveness. However, little we know about how Chinese international construction companies (CICCs) perceive procurement innovation and how it relates to their recent success. This research aims to capture their perspectives towards procurement innovation by interviewing nine key decision-makers of CICCs and experts in this area. It is found that CICCs are gradually adopting procurement innovation as a competitive strategy. Unlike the traditional life-or-death competition, competing through procurement innovation can make more projects possible; the emergence of CICCs, in particular their strengths, can be encouraged to deliver more projects and value in the international construction market. This research not only provides CICCs with insights into the procurement innovations in the construction sector, but also enables other companies to know CICCs with which they might compete or collaborate in the near future.published_or_final_versio
Competency and empowerment of project managers in China
The Agent Construction Management (ACM) system is one of the new measures adopted in government funded projects in China. The main characteristic of the ACM system is the introduction of an independent professional project management firm into the project management process. The ACM system is still in its trial stage in China and there is no unified qualification assessment system for agent construction organizations. While the importance of the project manager’s competence is recognized, previous research also shows that project manager’s empowerment is conducive to project performance. The definition of competency is confusing as several terms such as competency/competencies, competence/competences, capability and ability are used interchangeably and inconsistently. Competence is the state or quality of being adequately qualified -- the ability to perform a specific role (e.g. PMI’s project manager’s competency development framework). While empowerment can be viewed as a relational construct and considered within a more general concept of power, it is also a motivational (or psychological) construct. These two perspectives of empowerment are not independent and motivational empowerment may be an outcome of relational empowerment. This research aims to analyze the relationships of motivational empowerment and competency on job performance of the project managers in the ACM organisations. Regression modelling is adopted to analyze the data collected from 203 project managers involved in projects adopting ACM system. Findings support the relationships of competency and empowerment and their effect on project manager’s job performance.postprin
Sharpening Competitive Edge through Procurement Innovation: Perspectives from Chinese International Construction Companies
The international construction business is witnessing a trend towards the delivery of projects through the adoption of innovative procurement systems, which allow companies to gain competitive advantages and to potentially deliver enhanced value to society. Notably, Chinese companies are making steady inroads into the international construction market by enhancing competitiveness. However, we know little about the extent to which Chinese international construction companies (CICCs) perceive procurement innovation and how this factor may relate to their recent success. This research aims to fill the void based on interviews with nine CICC key decision‐makers and experts in this area, and the capturing of their perspectives. It is found that CICCs are gradually adopting procurement innovation as a competitive strategy. Although procurement innovation is conducive to competitive advantage in the long run, CICCs have to pay the cost of entering the new market. Thus a “wait‐and‐see” attitude exists in respect of a long term vision. Unlike the traditional win‐lose competitive bidding system, competing through procurement innovation can lead to larger, more suitable market presence. By succinctly describing the CICC story in the international market this research not only provides CICCs themselves with insights into current procurement innovations existing within the construction sector, but also enables other companies to understand the nature of CICCs with which they might compete or collaborate in the near future.postprin
Effect of CLIQ on training of HL-LHC quadrupole magnets
The high-luminosity LHC upgrade requires stronger than LHC low-beta
quadrupole magnets to reach the luminosity goals of the project. The project is
well advanced and HL-LHC quadrupole magnets are currently being commissioned in
US Labs (MQXFA magnets) and CERN (MQXFB magnets). Those are the first Nb3Sn
magnets to be used in any large particle accelerator. At development stages,
many Nb3Sn accelerator sub-scale models showed relatively slow training and
MQXFA magnets were projected to have low tens of quenches before reaching
operational field. Recently it was shown that dedicated capacitor-based devices
can affect Nb3Sn magnet training, and it was suggested that CLIQ, a
capacitor-based device intended for quench protection, can do too. The present
paper investigates effects on training likely induced by CLIQ, using the base
fact that only half the coils in a quadrupole experience upward current
modulation at quench because of capacitor discharge. The study encompasses all
MQXFA production magnets trained at BNL to date. No other high-statistics data
from identical magnets (series) with CLIQ protection exist so far. Implications
and opportunities stemming from data analysis are discussed and conclusions
drawn.Comment: Accepted versio
A Cognitive Ethology Study of First- and Third-Person Perspectives
The present investigation was funded by a grant awarded to AK by the Natural Sciences and Engineering Council of Canada. The funders had no role in study design, data collection, and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD
Fundamental scaling laws of on-off intermittency in a stochastically driven dissipative pattern forming system
Noise driven electroconvection in sandwich cells of nematic liquid crystals
exhibits on-off intermittent behaviour at the onset of the instability. We
study laser scattering of convection rolls to characterize the wavelengths and
the trajectories of the stochastic amplitudes of the intermittent structures.
The pattern wavelengths and the statistics of these trajectories are in
quantitative agreement with simulations of the linearized electrohydrodynamic
equations. The fundamental distribution law for the durations
of laminar phases as well as the power law of the amplitude distribution
of intermittent bursts are confirmed in the experiments. Power spectral
densities of the experimental and numerically simulated trajectories are
discussed.Comment: 20 pages and 17 figure
Direct observation of twist mode in electroconvection in I52
I report on the direct observation of a uniform twist mode of the director
field in electroconvection in I52. Recent theoretical work suggests that such a
uniform twist mode of the director field is responsible for a number of
secondary bifurcations in both electroconvection and thermal convection in
nematics. I show here evidence that the proposed mechanisms are consistent with
being the source of the previously reported SO2 state of electroconvection in
I52. The same mechanisms also contribute to a tertiary Hopf bifurcation that I
observe in electroconvection in I52. There are quantitative differences between
the experiment and calculations that only include the twist mode. These
differences suggest that a complete description must include effects described
by the weak-electrolyte model of electroconvection
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