689 research outputs found
Knowledge Worker Roles and Actions - Results of Two Empirical Studies
Reinhardt, W., Schmidt, B., Sloep, P. B., & Drachsler, H. (2011). Knowledge Worker Roles and Actions - Results of Two Empirical Studies. Knowledge and Process Management, 18(3), 150–174. doi: 10.1002/kpm.378 Online: http://onlinelibrary.wiley.com/doi/10.1002/kpm.378/abstractThis paper proposes a typology of knowledge workers and their respective knowledge actions. The extant literature on the definition of knowledge work actions is examined and evaluated. The existing classifications of roles of knowledge workers are evaluated and extended with additional literature and empirical findings definition of a typology of knowledge worker roles. The empirical data in this paper comes from two studies. In the Task Execution Study 20 knowledge worker had to carry out a selection of prepared tasks. The computer system that the participants were using was equipped with sensors, so the execution steps of the tasks could be traced and analyzed. The data from the second study comes from a questionnaire survey of knowledge workers, which yielded 43 responses. The paper shows that the sampled users take on all identified knowledge worker roles and that the knowledge work actions can be recognized in the sensor data from the first study. This paper contributes to the literature by proposing a new way of classifying the roles of knowledge workers and the knowledge actions they perform during their daily work. Furthermore, the paper provides a preliminary understanding of the relation between knowledge-intense work tasks, the roles they are executed in and the tools that are used to accomplish the respective tasks.The work presented in this paper has been partly funded by the German Federal Ministry of Education and Research under grant no. 01IA08006
Cosmic-ray induced background intercomparison with actively shielded HPGe detectors at underground locations
The main background above 3\,MeV for in-beam nuclear astrophysics studies
with -ray detectors is caused by cosmic-ray induced secondaries. The
two commonly used suppression methods, active and passive shielding, against
this kind of background were formerly considered only as alternatives in
nuclear astrophysics experiments. In this work the study of the effects of
active shielding against cosmic-ray induced events at a medium deep location is
performed. Background spectra were recorded with two actively shielded HPGe
detectors. The experiment was located at 148\,m below the surface of the Earth
in the Reiche Zeche mine in Freiberg, Germany. The results are compared to data
with the same detectors at the Earth's surface, and at depths of 45\,m and
1400\,m, respectively.Comment: Minor errors corrected; final versio
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Training and pattern recognition in layered automata
The project herein described, presents the results of an investigation
in the relatively new and expanding field of computer stimulated
learning machines for use in pattern recognition.
A learning machine, one that benefits from its past experience
was devised in computer program form. It may be described as a
Piecewise-Linear, layer, learning machine, Efforts were made to
ascertain the major parameters, properties, requirements and so on,
that determine its behavior. Once a feeling for the idiosyncracies
of the machine had been developed, a second. goal was to devise an
effective training procedure and obtain an estimate as to the accuracy
that may be obtained in pattern classification and extrapolation
problems.
We denote "training" as that phase during which one attempts to
develop the machine's ability to differentiate between various examples of pattern categories by some means of an interactive error
correction procedure; and the "decision" or "extrapolation" phase
as that during which unknown, uncategorized patterns are presented to
the machine for judgement
Confirmation of the existence of coherent orientations of quasar polarization vectors on cosmological scales
In order to verify the existence of coherent orientations of quasars
polarization vectors on very large scales, we have obtained new polarization
measurements for a sample of quasars located in a given region of the
three-dimensional Universe where the range of polarization position angles was
predicted in advance. For this new sample, the hypothesis of uniform
distribution of polarization position angles may be rejected at the 1.8%
significance level on the basis of a simple binomial test. This result provides
an independent confirmation of the existence of alignments of quasar
polarization vectors on very large scales. In total, out of 29 polarized
quasars located in this region of the sky, 25 have their polarization vectors
coherently oriented. This alignment occurs at redshifts 1-2 suggesting the
presence of correlations in objects or fields on Gpc scales. More global
statistical tests applied to the whole sample of polarized quasars distributed
all over the sky confirm that polarization vectors are coherently oriented in a
few groups of 20-30 quasars. Some constraints on the phenomenon are also
derived. Considering more particularly the quasars in the selected region of
the sky, we found that their polarization vectors are roughly parallel to the
plane of the Local Supercluster. But the polarization vectors of objects along
the same line of sight at lower redshifts are not accordingly aligned. We also
found that the known correlations between quasar intrinsic properties and
polarization are not destroyed by the alignment effect. Several possible
mechanisms are discussed, but the interpretation of this orientation effect
remains puzzling.Comment: Accepted for publication in Astronomy & Astrophysic
Physical activity in 9–15 year-old pediatric cancer survivors compared to a nationwide sample
Introduction: Sufficient physical activity (PA) has the potential to mitigate late effects of cancer, but objective data of PA levels in adolescents are scarce. The aim of this study was to investigate differences in PA behavior between childhood cancer survivors (CCS) and healthy peers.
Methods: PA levels of n = 74 CCS and n = 1304 healthy peers from the MoMo study aged 9–15 years were assessed with validated objective accelerometry and group means were compared. A binary multiple logistic regression was performed to investigate the potential predictors of PA.
Results: CCS spent significantly more time sedentary (p < 0.001) and less time in moderate-to-vigorous physical activity (p = 0.002) compared to the healthy cohort. Subgroup analysis revealed the largest deviations of PA levels for CCS aged 9–11 years who fulfilled international PA recommendations on significantly fewer days than MoMo (p < 0.01). Health conditions seem to be a predictor concerning the fulfillment of international PA recommendations by the WHO (p = 0.015).
Conclusions: Our study identified vulnerable groups which seem to require targeted exercise and health behavior change programs to increase physical activity and reduce sedentary time. The presence of treatment sequelae as a significant predictor of insufficient physical activity underlines the need of multidisciplinary supportive care approaches
On the Landau Ginzburg theory of MAG projected SU(2) lattice gauge theory
Maximal Abelian gauge fixing and subsequent Abelian projection of SU(2)
lattice gauge theory defines closed trajectories of magnetic monopoles. These
trajectories can be interpreted in terms of an effective scalar field theory of
the MAG monopoles using the worldline representation of the functional
determinants. Employing the monopole worldlines detected in the numerical
simulation, we show that a scalar bound state exists. The screening mass of
this state properly scales towards the continuum limit. We find m ~ 1.3 $GeV
when the string tension sigma = 440 MeV is used as reference scale.Comment: 9 pages, 3 figures, accepted by Phys. Lett.
Blended-ALMAMAR app for inpatient mental health care for refugees: study protocol for a multicenter implementation study within the I-REACH consortium (Internet based REfugee mentAl healtH Care)
Background
Refugees are at high risk for developing mental illnesses. Due to language and cultural barriers, there is need for specifically adapted therapeutic procedures for refugees in inpatient mental health care settings. Internet-based applications in refugee mother tongues have the potential to improve the outcomes of mental health care for this vulnerable population. The key research question of the present implementation study is whether the newly developed “blended ALMAMAR” app for Arabic and Farsi speaking refugees in Germany is used and accepted by patients and professionals in routine inpatient mental health care (blended care).
Methods
We present the design of an observational, prospective multicenter implementation study in eight psychiatric hospitals. We plan to recruit 100 Farsi or Arabic speaking refugees receiving in-patient treatment due to depression, anxiety disorder, posttraumatic stress disorder or substance use disorders. These patients will get access to the “blended ALMAMAR” app during their inpatient stay in a blended-care approach. We will assess the usage (e.g., duration and frequency of use of the app) as well as subjective acceptability and usability of the intervention. To identify sociodemographic and clinical factors associated with “blended ALMAMAR” usage, we will also perform clinical and questionnaire assessments.
Discussion
The newly developed “blended ALMAMAR” app may help to close communication gaps for the hard-to reach and vulnerable group of refugees in inpatient mental health care. It is the first blended-care intervention that addresses severely mentally ill refugees in an inpatient psychiatric setting in Germany.
Trial registration
The trial was registered in the German Clinical Trials Register on November 11, 2021 (DRKS00025972) and adapted on November 14, 2023
Cosmic-ray-induced background intercomparison with actively shielded HPGe detectors at underground locations
The main background above 3 MeV for in-beam nuclear astrophysics studies with γ-ray detectors is caused by cosmic-ray induced secondaries. The two commonly used suppression methods, active and passive shielding, against this kind of background were formerly considered only as alternatives in nuclear astrophysics experiments. In this work the study of the effects of active shielding against cosmic-ray induced events at a medium deep location is performed. Background spectra were recorded with two actively shielded HPGe detectors. The experiment was located at 148 m below the surface of the Earth in the Reiche Zeche mine in Freiberg, Germany. The results are compared to data with the same detectors at the Earth’s surface, and at depths of 45 m and 1400 m, respectively
A kinetic approach to eta' production from a CP-odd phase
The production of (eta,eta')- mesons during the decay of a CP-odd phase is
studied within an evolution operator approach. We derive a quantum kinetic
equation starting from the Witten-DiVecchia-Veneziano Lagrangian for
pseudoscalar mesons containing a U_A(1) symmetry breaking term. The non-linear
vacuum mean field for the flavour singlet pseudoscalar meson is treated as a
classical, self-interacting background field with fluctuations assumed to be
small. The numerical solution provides the time evolution of momentum
distribution function of produced eta'- mesons after a quench at the
deconfinement phase transition. We show that the time evolution of the momentum
distribution of the produced mesons depend strongly on the shape of the
effective potential at the end of the quench, exhibiting either parametric or
tachyonic resonances. Quantum statistical effects are essential and lead to a
pronounced Bose enhancement of the low momentum states.Comment: 10 pages, latex, epsfig, 6 figure
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