95 research outputs found
Differential Coded Aperture Single-Snapshot Spectral Imaging
We propose a novel concept of differential coded aperture snapshot spectral
imaging (D-CASSI) technique exploiting the benefits of using {-1,+1} random
mask, which is demonstrated by a broadband single-snapshot hyperspectral camera
using compressed sensing. To double the information, we encode the image by two
complementary random masks, which proved to be superior to two independent
patterns. We utilize dispersed and non-dispersed encoded images captured in
parallel onto a single detector. We explored several different approaches to
processing the measured data, which demonstrates significant improvement in
retrieving complex hyperspectral scenes. The experiments were completed by
simulations in order to quantify the reconstruction fidelity. The concept of
differential CASSI could be easily implemented also by multi-snapshot CASSI
without any need for optical system modification
Enhancement of CASSI by a zero-order image employing a single detector
Coded aperture snapshot spectral imaging (CASSI) makes it possible to recover
3D hyperspectral data from a single 2D image. However, the reconstruction
problem is severely underdetermined and efforts to improve the compression
ratio typically make the imaging system more complex and cause a significant
loss of incoming light intensity. In this paper, we propose a novel approach to
CASSI which enables capturing both spectrally sheared and integrated image of a
scene with a single camera. We performed hyperspectral imaging of three
different testing scenes in the spectral range of 500-900 nm. We demonstrate
the prominent effect of using the non-diffracted image on the reconstruction of
data from our camera. The use of the spectrally integrated image improves the
reconstruction quality and we observed an approx. fivefold reduction in
reconstruction time
Critical life events as potential for biographical learning. Learning in the context of a failed AC for executives
Die hier vorliegende Arbeit leistet einen Beitrag zur Erforschung von Lernprozessen in biographischen Zusammenhängen. Im Zentrum der Betrachtung stehen kritische Lebensereignisse als Impulsgeber. Konkret wird die Untersuchung an dem kritischen Lebensereignis ‚Nichtbestehen eines Assessment Centers (ACs) zur Zulassung einer Führungsaufgabe’ durchgeführt. Ziel der Untersuchung ist es, herauszufinden, welche Lernprozesse bei unterschiedlichen Individuen in Folge des Nichtbestehens des ACs zu beobachten sind. Im Rahmen der Untersuchung stehen dabei drei unterschiedliche Analyseebenen im Fokus: die Einzelfallanalyse, die fallübergreifende und die fallvergleichende Analyse. Darüber hinaus ist die Untersuchung in einem Paneldesign angelegt, um zusätzlich einen Beitrag über die Veränderungen jener Lernprozesse im zeitlichen Verlauf leisten zu können. Im Rahmen der Datenerhebung sind dafür zwölf Interviews in der Panelwelle t1 und aufgrund der Panelmortalität elf Interviews in der Panelwelle t2 mit AC-Teilnehmer(inne)n, die das Verfahren nicht bestanden haben, geführt worden. Für alle drei Ebenen gilt, dass Lernprozesse sowohl auf mentaler als auch auf aktionaler Ebene eintreten und zudem im zeitlichen Verlauf und durch weitere (Lebens-) Ereignisse einer Veränderungsdynamik unterliegen.This article intends to deepen the knowledge of learning processes in a biographic context with special regards to critical life events as a driving force. The study focusses on the specific critical life event of not passing the respective assessment center (ac) when striving for a managerial function. The aim of the study was to show which learning processes surfaced within multiple individuals as a reaction to said critical life event. The study applies three different analytical levels: individual case-, cross individual case- and comparative analysis. In order to evaluate the just described cases, a panel design has been made use of to enable the examination of educational and learning processes along a given time span. The analysis is based on a data collection extended in two waves. Twelve interviews have been conducted at t1, eleven interviews at t2 due to the mortal nature of panels. All of the interviewees have experienced the same critical life event and have not been given the opportunity to succeed in a managerial function. The results of the analysis returned valuable information on all of the analytical levels and gave proof that learning processes were triggered on each of the observed levels. Thereby excluding neither mental nor physical processes adding that all of the observed processes have experienced various changes over time caused by dynamics, such as additional critical life events
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