805 research outputs found
Towards a case-based learning approach to support software architecture education
Software architecture education remains challenging for instructors,
students, and software industry professionals. Several initiatives have been
proposed to mitigate the inherent challenges, including games, supporting
tools, collaborative courses, and hands-on projects. Case-based learning has
been introduced in software architecture, and its benefits are recognized.
However, choosing the right cases that cover the stated learning objectives and
developing learning activities to achieve high-order learning are also
challenging. The main goal of this paper is to present a case-based learning
approach that guides the development of learning objectives, the finding and
selection of real-world software architecture cases, and the design of
instructional activities. We applied our approach in software architecture
related courses during the past few years. The results show that it can
leverage the ways to adequately explore cases for educational purposes while
also motivating instructors and students to the software architecture
education
Content-Free Cueing as a Technique to Inhibit Mind Wandering and Treat Anhedonia in Depression
This thesis addresses the relationship between mind wandering and mood. Mind wandering is defined as a state of ‘decoupled attention’ removed from the immediate contexts towards unrelated thoughts and feelings (Smallwood & Schooler, 2006). Part one is a literature review that investigates the association between mind wandering and mood. It examines whether mind wandering affects mood and vice versa, and how mind wandering relates to mood disorder. Overall the findings were inconsistent. Gaps in the literature are highlighted and suggestions for future research are discussed. Part two consists of an empirical paper investigating if content-free cues in the form of auditory tones can reduce mind wandering and enhance mood. It furthermore examines if the beneficial effects of cuing are more pronounced in individuals with increasing depression severity. While cues led to a reduction in mind wandering in two laboratory tasks, this did not translate into pleasant every-day activities carried out at home. There was furthermore only weak support for the effects of cues on mood and contrary to predictions depression severity did not moderate the effects of cues. Limitations of the design and suggestion for further research are discussed along with clinical implications. Part three is a critical appraisal, which discusses the research designs, methods and testing and makes suggestions for future research. It closes with personal reflections on completing the thesis
Nuclear Fusion via Triple Collisions in Solar Plasma
We consider several nuclear fusion reactions that take place at the center of
the sun, which are omitted in the standard pp-chain model. More specifically
the reaction rates of the nonradiative production of ^3He, ^7Be, and ^8B nuclei
in triple collisions involving electrons are estimated within the framework of
the adiabatic approximation. These rates are compared with those of the
corresponding binary fusion reactions.Comment: 3 pages, latex (RevTex), no figure
VARIABILITY OF STRIDE FREQUENCY AND PRONATION VELOCITY DURING A 16 DAY RELAY-RUN AROUND GERMANY – A CASE STUDY
This case study analyzed stride frequency, represented by time of gait cycle (TGC), and maximum pronation velocity (MPV) for one subject running 350 km over 16 consecutive days. Data collection took place during a day-and-night team relay-race around Germany in 2008. TGC and MPV measurements were performed by a gyrometer incorporated in the subject’s running shoe and recorded by a portable data logger. For data analysis TGC and MPV velocity were determined in 25 runs for altogether 112,532 steps of the right foot. Means and standard deviations of both parameters for complete runs and for all consecutive five-minute segments within each run were calculated. Results showed an increase of TGC and a decrease of MPV within single runs. Between run comparisons across all 25 runs showed no systematic change in TGC and MPV during the relay-race. Interestingly, during the unfamiliar night-runs TGC and MPV were increased compared to day-runs, potentially caused by altered biorhythm or limited vision at night
Flexural strength and elastic modulus evaluation of structures made by conventional PMMA and PMMA reinforced with graphene
Abstract. – OBJECTIVE: The aim of this study
was to compare both the elastic modulus (EM)
and the flexural strength (FS) of two materials
used in dental prosthesis, namely polymethylmethacrylate (PMMA) and polymethylmethacrylate reinforced with graphene (G-PMMA).
MATERIALS AND METHODS: Twenty rectangular samples were manufactured by a milling machine and divided into two groups (n=
10/group): Group 1, PMMA; Group 2, G-PMMA.
The specimens were subjected to a three-point
bending test conducted in the elastic range to
evaluate EM. A similar test was protracted until
fracture to evaluate FS. Data on EM and FS were
statistically analyzed with independent-samples t-test in order to compare the two groups.
A scanning electron microscope (SEM) (5.00 kx
and 1.00 kx magnification) was used to evaluate
the morphology of sample’s fracture.
RESULTS: Compared to PMMA samples, each
G-PMMA sample showed significantly higher
values of FS (p <0.001) and EM (p <0.001). SEM
images analysis showed an inhomogeneous
fracture morphology in G-PMMA samples.
CONCLUSIONS: The results show that G-PMMA is a promising material to be used for prosthetic purposes. This is demonstrated by a significant increase in both peak load and bending
stiffness, resulting from the bending test performed on G-PMMA samples. Furthermore, the
latter exhibit greater homogeneity in their mechanical behavior, supporting the potential value of this material in dental prosthesis
Magneto-optics of massive Dirac fermions in bulk Bi2Se3
We report on magneto-optical studies of Bi2Se3, a representative member of
the 3D topological insulator family. Its electronic states in bulk are shown to
be well described by a simple Dirac-type Hamiltonian for massive particles with
only two parameters: the fundamental bandgap and the band velocity. In a
magnetic field, this model implies a unique property - spin splitting equal to
twice the cyclotron energy: Es = 2Ec. This explains the extensive
magneto-transport studies concluding a fortuitous degeneracy of the spin and
orbital split Landau levels in this material. The Es = 2Ec match differentiates
the massive Dirac electrons in bulk Bi2Se3 from those in quantum
electrodynamics, for which Es = Ec always holds.Comment: 5 pages, 3 figures and Supplementary materials, to be published in
Physical Review Letter
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