181 research outputs found
Leadership as a bottleneck factor in CRM. Or: What could be learned from Alinghi
El profesionalismo y la administración de relaciones con el cliente no se detienen con los sistemas y estrategias, el éxito real de los acercamientos prometedores sólo se puede lograr por medio de una nueva orientación y administración. Esto incluye la comprensión de la administración como un marco de referencia existencial que está basado en la confianza, ya que todos los ejemplos presentados muestran que el CRMtrata con nuevas situaciones, pruebas, problemas y errores, además de cómo tratar con incidentes inesperados. Cuando un gerente no es capaz de mostrar fe en sus empleados y de establecer una administración que ve los errores de forma positiva (el error como la mejor forma de aprendizaje) como base de la organización, las mejores auditorías y los mejores procedimientos están perdidos. si este entendido básico es probable que exista en algún lado, resultados positivos del CRM pueden ser obtenidos a corto plazo, debido a análisis consecuentes y a la realización de lineamientos a seguir —y con la introspección continua y la repetición de procedimientos, los cuales pueden servir como ventaja competitiva independiente para un individuo en particular
Single-photon single ionization of W ions: experiment and theory
Experimental and theoretical results are reported for photoionization of
Ta-like (W) tungsten ions. Absolute cross sections were measured in the
energy range 16 to 245 eV employing the photon-ion merged-beam setup at the
Advanced Light Source in Berkeley. Detailed photon-energy scans at 100 meV
bandwidth were performed in the 16 to 108 eV range. In addition, the cross
section was scanned at 50 meV resolution in regions where fine resonance
structures could be observed. Theoretical results were obtained from a
Dirac-Coulomb R-matrix approach. Photoionization cross section calculations
were performed for singly ionized atomic tungsten ions in their , =1/2, ground level and the associated
excited metastable levels with =3/2, 5/2, 7/2 and 9/2. Since the ion beams
used in the experiments must be expected to contain long-lived excited states
also from excited configurations, additional cross-section calculations were
performed for the second-lowest term, 5d^5 \; ^6{\rm S}_{J}, =5/2, and for
the F term, 5d^3 6s^2 \; ^4{\rm F}_{J}, with = 3/2, 5/2, 7/2 and 9/2.
Given the complexity of the electronic structure of W the calculations
reproduce the main features of the experimental cross section quite well.Comment: 23 pages, 7 figures, 1 table: Accepted for publication in J. Phys. B:
At. Mol. & Opt. Phy
Finite-sample frequency distributions originating from an equiprobability distribution
Given an equidistribution for probabilities p(i)=1/N, i=1..N. What is the
expected corresponding rank ordered frequency distribution f(i), i=1..N, if an
ensemble of M events is drawn?Comment: 4 pages, 4 figure
Near--K-edge double and triple detachment of the F- negative ion: observation of direct two-electron ejection by a single photon
Double and triple detachment of the F-(1s2 2s2 2p6) negative ion by a single
photon have been investigated in the photon energy range 660 to 1000 eV. The
experimental data provide unambiguous evidence for the dominant role of direct
photo-double-detachment with a subsequent single-Auger process in the reaction
channel leading to F2+ product ions. Absolute cross sections were determined
for the direct removal of a (1s+2p) pair of electrons from F- by the absorption
of a single photon
Self-supervised contrastive learning of echocardiogram videos enables label-efficient cardiac disease diagnosis
Advances in self-supervised learning (SSL) have shown that self-supervised
pretraining on medical imaging data can provide a strong initialization for
downstream supervised classification and segmentation. Given the difficulty of
obtaining expert labels for medical image recognition tasks, such an
"in-domain" SSL initialization is often desirable due to its improved label
efficiency over standard transfer learning. However, most efforts toward SSL of
medical imaging data are not adapted to video-based medical imaging modalities.
With this progress in mind, we developed a self-supervised contrastive learning
approach, EchoCLR, catered to echocardiogram videos with the goal of learning
strong representations for efficient fine-tuning on downstream cardiac disease
diagnosis. EchoCLR leverages (i) distinct videos of the same patient as
positive pairs for contrastive learning and (ii) a frame re-ordering pretext
task to enforce temporal coherence. When fine-tuned on small portions of
labeled data (as few as 51 exams), EchoCLR pretraining significantly improved
classification performance for left ventricular hypertrophy (LVH) and aortic
stenosis (AS) over other transfer learning and SSL approaches across internal
and external test sets. For example, when fine-tuning on 10% of available
training data (519 studies), an EchoCLR-pretrained model achieved 0.72 AUROC
(95% CI: [0.69, 0.75]) on LVH classification, compared to 0.61 AUROC (95% CI:
[0.57, 0.64]) with a standard transfer learning approach. Similarly, using 1%
of available training data (53 studies), EchoCLR pretraining achieved 0.82
AUROC (95% CI: [0.79, 0.84]) on severe AS classification, compared to 0.61
AUROC (95% CI: [0.58, 0.65]) with transfer learning. EchoCLR is unique in its
ability to learn representations of medical videos and demonstrates that SSL
can enable label-efficient disease classification from small, labeled datasets
Dissolution of coccolithophorid calcite by microzooplankton and copepod grazing
International audienceIndependent of the ongoing acidification of surface seawater, the majority of the calcium carbonate produced in the pelagial is dissolved by natural processes above the lysocline. We investigate to what extent grazing and passage of coccolithophorids through the guts of copepods and the food vacuoles of microzooplankton contribute to calcite dissolution. In laboratory experiments where the coccolithophorid Emiliania huxleyi was fed to the rotifer Brachionus plicatilis, the heterotrophic flagellate Oxyrrhis marina and the copepod Acartia tonsa, calcite dissolution rates of 45?55%, 37?53% and 5?22% of ingested calcite were found. We ascribe higher loss rates in microzooplankton food vacuoles as compared to copepod guts to the strongly acidic digestion and the individual packaging of algal cells. In further experiments, specific rates of calcification and calcite dissolution were also measured in natural populations during the PeECE III mesocosm study under differing ambient pCO2 concentrations. Microzooplankton grazing accounted for between 27 and 70% of the dynamic calcite stock being lost per day, with no measurable effect of CO2 treatment. These measured calcite dissolution rates indicate that dissolution of calcite in the guts of microzooplankton and copepods can account for the calcite losses calculated for the global ocean using budget and model estimates
advanced electric propulsion diagnostic tools at iom
Abstract Recently, we have set up an Advanced Electric Propulsion Diagnostic (AEPD) platform [1] , which allows for the in-situ measurement of a comprehensive set of thruster performance parameters. The platform utilizes a five-axis-movement system for precise positioning of the thruster with respect to the diagnostic heads. In the first setup (AEPD1) an energy-selective mass spectrometer (ESMS) and a miniaturized Faraday probe for ion beam characterization, a telemicroscope and a triangular laser head for measuring the erosion of mechanical parts, and a pyrometer for surface temperature measurements were integrated. The capabilities of the AEPD1 platform were demonstrated with two electric propulsion thrusters, a gridded ion thruster RIT 22 (Airbus Defence & Space, Germany, [13]) and a Hall effect thruster SPT 100D EM1 (EDB Fakel, Russia, [1] , [4] ), in two different vacuum facilities
- …