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See detailDifficulties in disengaging attentional resources from self-generated thoughts moderate the link between dysphoria and maladaptive self-referential thinking.
Rochat, Lucien; Billieux, Joël UL; Van der Linden, Martial

in Cognition and Emotion (2012), 26(4), 748-57

Negative emotions increase self-focused attention, a core feature of depression and anxiety-related disorders. However, the cognitive mechanisms associated with the tendency to self-focus-and, conversely ... [more ▼]

Negative emotions increase self-focused attention, a core feature of depression and anxiety-related disorders. However, the cognitive mechanisms associated with the tendency to self-focus-and, conversely, with the ability to voluntarily disengage attentional resources from the self and direct them towards the external environment-remain poorly understood. Thus, this study aimed to examine whether a specific cognitive control mechanism that directs attention between self-generated thoughts and external information might moderate the relationship between dysphoria and maladaptive self-referential thinking. Results showed that dysphoria increases the frequency of rumination, self-blame, and catastrophising, especially for participants who have more difficulty in switching from self-generated thoughts to information provided by the environment. These results shed new light on the cognitive mechanisms underlying maladaptive self-referential thinking associated with dysphoria. More specifically, this specific cognitive mechanism might play a key role in the maintenance or amplification of a depressed mood. [less ▲]

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See detailDifficulty-level modeling of ontology-based factual questions
Ellampallil Venugopal, Vinu UL; Kumar, P Sreenivasa

in Semantic Web – Interoperability, Usability, Applicability (2020)

Semantics-based knowledge representations such as ontologies are found to be very useful in automatically generating meaningful factual questions. Determining the difficulty-level of these system ... [more ▼]

Semantics-based knowledge representations such as ontologies are found to be very useful in automatically generating meaningful factual questions. Determining the difficulty-level of these system-generated questions is helpful to effectively utilize them in various educational and professional applications. The existing approach for for predicting the difficulty-level of factual questions utilizes only few naive features and, its accuracy (F-measure) is found to be close to only 50% while considering our benchmark set of 185 questions. In this paper, we propose a new methodology for this problem by identifying new features and by incorporating an educational theory, related to difficulty-level of a question, called Item Response Theory (IRT). In the IRT, knowledge proficiency of end users (learners) are considered for assigning difficulty-levels, because of the assumptions that a given question is perceived differently by learners of various proficiency levels. We have done a detailed study on the features/factors of a question statement which could possibly determine its difficulty-level for three learner categories (experts, intermediates, and beginners). We formulate ontology-based metrics for the same. We then train three logistic regression models to predict the difficulty-level corresponding to the three learner categories. The output of these models is interpreted using the IRT to find a question’s overall difficulty-level. The accuracy of the three models based on cross-validation is found to be in satisfactory range (67-84%). The proposed model (containing three classifiers) outperforms the existing model by more than 20% in precision, recall and F1-score measures. [less ▲]

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See detailDiffractive paths for weak localization in quantum billiards
Brezinova, Iva; Stampfer, Christoph; Wirtz, Ludger UL et al

in Physical Review. B (2008), 77(16),

We study the weak-localization effect in quantum transport through a clean ballistic cavity with regular classical dynamics. We address the question which paths account for the suppression of conductance ... [more ▼]

We study the weak-localization effect in quantum transport through a clean ballistic cavity with regular classical dynamics. We address the question which paths account for the suppression of conductance through a system where disorder and chaos are absent. By exploiting both quantum and semiclassical methods, we unambiguously identify paths that are diffractively backscattered into the cavity (when approaching the lead mouths from the cavity interior) to play a key role. Diffractive scattering couples transmitted and reflected paths and is thus essential to reproduce the weak-localization peak in reflection and the corresponding antipeak in transmission. A comparison of semiclassical calculations featuring these diffractive paths yields good agreement with full quantum calculations and experimental data. Our theory provides system-specific predictions for the quantum regime of few open lead modes and can be expected to be relevant also for mixed as well as chaotic systems. [less ▲]

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See detailDiffuse Electroreflectance of thin-film solar cells: Suppression of interference-related lineshape distortions
Krämmer, Christoph; Huber, Christian; Redinger, Alex UL et al

in Applied Physics Letters (2015), 107

Detailed reference viewed: 157 (5 UL)
See detailDiffusion approximations via Stein's method and time changes
Kasprzak, Mikolaj UL

E-print/Working paper (2017)

Detailed reference viewed: 47 (1 UL)
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See detailDiffusion in nonuniform temperature and its geometric analog
Polettini, Matteo UL

in Physical Review. E ,Statistical, Nonlinear, and Soft Matter Physics (2013), 87

We propose a Langevin equation for systems in an environment with nonuniform temperature. At odds with an older proposal, ours admits a locally Maxwellian steady state, local equipartition holds, and for ... [more ▼]

We propose a Langevin equation for systems in an environment with nonuniform temperature. At odds with an older proposal, ours admits a locally Maxwellian steady state, local equipartition holds, and for detailed-balanced (reversible) systems statistical and physical entropies coincide. We describe its thermodynamics, which entails a generalized version of the first law and Clausius's characterization of reversibility. Finally, we show that a Brownian particle constrained into a smooth curve behaves according to our equation, as if experiencing nonuniform temperature. [less ▲]

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See detailDiffusion semigroup on manifolds with time-dependent metrics
Cheng, Li Juan UL

in Forum Mathematicum (2017), 29(4), 751-1002

Let $L_t:=\Delta_t +Z_t $, $t\in [0,T_c)$ on a differential manifold equipped with a complete geometric flow $(g_t)_{t\in [0,T_c)}$, where $\Delta_t$ is the Laplacian operator induced by the metric $g_t ... [more ▼]

Let $L_t:=\Delta_t +Z_t $, $t\in [0,T_c)$ on a differential manifold equipped with a complete geometric flow $(g_t)_{t\in [0,T_c)}$, where $\Delta_t$ is the Laplacian operator induced by the metric $g_t$ and $(Z_t)_{t\in [0,T_c)}$ is a family of $C^{1,\infty}$-vector fields. In this article, we present a number of equivalent inequalities for the lower bound curvature condition, which include gradient inequalities, transportation-cost inequalities, Harnack inequalities and other functional inequalities for the semigroup associated with diffusion processes generated by $L_t$. To this end, we establish the derivative formula for the associated semigroup and construct couplings for these diffusion processes by parallel displacement and reflection. [less ▲]

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See detailDiffusion tensor imaging--arcuate fasciculus and the importance for the neurosurgeon.
Hana, Ardian; Dooms, Georges; Boecher-Schwarz, Hans et al

in Clinical neurology and neurosurgery (2015), 132

OBJECTIVE: Tumors in eloquent areas of the brain like Broca or Wernicke might have disastrous consequences for patients. We intended to visualize the arcuate fasciculus (AF) and to demonstrate his ... [more ▼]

OBJECTIVE: Tumors in eloquent areas of the brain like Broca or Wernicke might have disastrous consequences for patients. We intended to visualize the arcuate fasciculus (AF) and to demonstrate his relation with the corticospinal tract and the visual pathway using diffusion tensor imaging (DTI). METHODS: We depicted between 2012 and 2014 the AF in 71 patients. Men and women of all ages were included. Eleven patients had postoperative controls also. We used a 3DT1-sequence for the navigation. Furthermore T2- and DTI-sequences were performed. The FOV was 200 x 200 mm(2), slice thickness 2mm, and an acquisition matrix of 96 x 96 yielding nearly isotropic voxels of 2 x 2 x 2 mm. 3-Tesla-MRI was carried out strictly axial using 32 gradient directions and one b0-image. We used Echo-Planar-Imaging (EPI) and ASSET parallel imaging with an acceleration factor of 2. b-Value was 800 s/mm(2). Additional scanning time was less than 9 min. RESULTS: AF was portrayed in 63 patients bilaterally. In one glioblastoma patient it was impossible to visualize the left AF and in seven other patients we could not portray the right one. The lesions affected AF by disrupting or displacing the fibers. CONCLUSIONS: DTI might be a useful tool to portray AF. It is time-saving and can be used to preserve morbidity in patients with lesions in eloquent brain areas. It might give deeper insights of the white matter and the reorganization of AF-fibers postoperatively. [less ▲]

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See detailDiffusion-based Virtual Graph Adjacency for Fourier Analysis of Network Signals
Elias, Vitor R. M.; Alves Martins, Wallace UL; Werner, Stefan

in XXXVIII SIMPÓSIO BRASILEIRO DE TELECOMUNICAÇÕES E PROCESSAMENTO DE SINAIS, Florianópolis 22-25 November 2020 (2020, November)

This work proposes a graph model for networks where node collaborations can be described by the Markov property. The proposed model augments an initial graph adjacency using diffusion distances. The ... [more ▼]

This work proposes a graph model for networks where node collaborations can be described by the Markov property. The proposed model augments an initial graph adjacency using diffusion distances. The resulting virtual adjacency depends on a diffusion-scale parameter, which leads to a controlled shift in the graph-Fourier-transform spectrum. This enables a frequency analysis tailored to the actual network collaboration, revealing more information on the graph signal when compared to traditional approaches. The proposed model is employed for anomaly detection in real and synthetic networks, and results confirm that using the proposed virtual adjacency yields better classification than the initial adjacency. [less ▲]

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See detailDifuzer: Uncovering Suspicious Hidden Sensitive Operations in Android Apps
Samhi, Jordan UL; Li, Li; Bissyande, Tegawendé François D Assise UL et al

in 44th International Conference on Software Engineering (ICSE 2022) (2022, May 21)

One prominent tactic used to keep malicious behavior from being detected during dynamic test campaigns is logic bombs, where malicious operations are triggered only when specific conditions are satisfied ... [more ▼]

One prominent tactic used to keep malicious behavior from being detected during dynamic test campaigns is logic bombs, where malicious operations are triggered only when specific conditions are satisfied. Defusing logic bombs remains an unsolved problem in the literature. In this work, we propose to investigate Suspicious Hidden Sensitive Operations (SHSOs) as a step towards triaging logic bombs. To that end, we develop a novel hybrid approach that combines static analysis and anomaly detection techniques to uncover SHSOs, which we predict as likely implementations of logic bombs. Concretely, Difuzer identifies SHSO entry-points using an instrumentation engine and an inter-procedural data-flow analysis. Then, it extracts trigger-specific features to characterize SHSOs and leverages One-Class SVM to implement an unsupervised learning model for detecting abnormal triggers. We evaluate our prototype and show that it yields a precision of 99.02% to detect SHSOs among which 29.7% are logic bombs. Difuzer outperforms the state-of-the-art in revealing more logic bombs while yielding less false positives in about one order of magnitude less time. All our artifacts are released to the community. [less ▲]

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See detailDigestion of grass silage in a semi-continuously fed reactor at increasing loading rates - Process stability and kinetics evaluatio
Benito Martin, Patricia Cristina UL; Greger, Manfred UL; Schlienz, Markus UL

in Venice 2014 5th International Symposium on Energy from Biomass and Waste Proceedings (2014, December 01)

Grass is a popular substrate in agricultural biogas plants in Central and Northern Europe. There is currently limited information about the impact of the organic loading rates (OLR) on methane yields ... [more ▼]

Grass is a popular substrate in agricultural biogas plants in Central and Northern Europe. There is currently limited information about the impact of the organic loading rates (OLR) on methane yields, process stability and kinetics for continuous systems digesting grass silage. Anaerobic mono-digestion of grass silage was evaluated in semi-continuously fed laboratory continuously stirred tank reactors (CSTRs) at increasing loading rates between 1.9 and 4.7gVS/l/d. Results show that digestion of grass silage in one-stage CSTR is feasible and do not present any loading-induced inhibition for the tested OLR range. While the volumetric methane production experienced an increase of 61%, the methane yield only decreased by 13% for the highest OLR. On the other hand, the estimated first-order hydrolysis constant decreased by 24% when increasing the loading from 1.9 to 4.7gVS/l/d, which related with an accumulation of the organic material in the reactor. It was also found that the composition of the grass silage affected the digester performance significantly. [less ▲]

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See detailDigging into Digital Roots: introduction
Ribeiro, Nelson; Schafer, Valerie UL

Scientific Conference (2021, July)

Presentation of the project at stake (a collective book whose idea was born within the ECREA Communication History Section), its approach and theoretical framework.

Detailed reference viewed: 76 (2 UL)
See detailDigging into web archives of the COVID crisis
Schafer, Valerie UL; Joshgun, Sirajzade; Susan, Aasman

Presentation (2022, May 11)

This presentation aimed at presenting the challenges, methodologies and issues related to the analysis of the IIPC COVID collection of web archives through a collaboration with the Archive Unleashed Team.

Detailed reference viewed: 39 (2 UL)
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See detailDigging up Foucault for teacher education: Archeology, conservation and the hauntology of pedagogy.
Biesta, Gert UL

in IJHE Bildungsgeschichte (2011), 1(2), 189-191

Detailed reference viewed: 123 (0 UL)
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See detailDigit ratio (2D:4D) and short-term mating orientation
Schwarz, Sascha; Mustafic, Maida UL; Hassabrauck, Manfred

Scientific Conference (2008, July)

Detailed reference viewed: 42 (2 UL)
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See detailDigit ratio (2D:4D), sex differences, and various forms of aggression.
Baudson, Tanja Gabriele UL; Stiensmeier-Pelster, J.

Scientific Conference (2006)

Detailed reference viewed: 62 (0 UL)
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See detailDigital (r) evolution in private customer business \ "a ft? Call to banks to act proactively
Buhl, Hans Ulrich; Eistert, Torsten; Fridgen, Gilbert UL et al

in Die Bank (2012), 52(6), 46--50

Detailed reference viewed: 35 (1 UL)