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See detailDiffusion approximations via Stein's method and time changes
Kasprzak, Mikolaj UL

E-print/Working paper (2017)

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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.

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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)

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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)

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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: 31 (1 UL)
See detailA digital and interactive historical atlas of the city of Luxembourg.
Uhrmacher, Martin UL; Kass, Steve UL

Scientific Conference (2018, September 20)

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See detailThe Digital Archive and the Politics of Digitisation
Zaagsma, Gerben UL

Scientific Conference (2022, March 10)

In this paper I will discuss key parameters of the politics of digitisation within a broader historical and global context with the aim to encourage further debate on its implications for historical ... [more ▼]

In this paper I will discuss key parameters of the politics of digitisation within a broader historical and global context with the aim to encourage further debate on its implications for historical research. In the first part, I will outline the global dimensions of the politics of digital cultural heritage with a particular focus on developments within and between Europe and Africa, framed within the broader context of the politics of heritage and its preservation and recent debates about ‘postcolonial digital humanities’. In the second part, I will discuss the history and current state of digitisation in Europe and Africa. Here I will partly draw upon the web archive of the IFLA/Unesco Directory of Digitised Library Collections (2002-2006) and recent global and European digitisation surveys. The paper will conclude by highlighting the paradoxical situation we currently face with regard to digitisation and the state of ‘memory’ in both the global North and South. [less ▲]

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See detailThe Digital Archive and the Politics of Digitisation
Zaagsma, Gerben UL

Presentation (2021, April 28)

This talk deals with a question that is becoming increasingly important for historians who work with digitised cultural heritage: what are the politics of digitisation and what are its implications for ... [more ▼]

This talk deals with a question that is becoming increasingly important for historians who work with digitised cultural heritage: what are the politics of digitisation and what are its implications for historical research? Is the often-lauded democratising potential of digitisation also offset by risks, inherent in selection processes that might privilege the digitisation of heritage corresponding to existing national master narratives, the availability of funding and/or the priorities set by cultural policies and certain research agendas? How does transnational heritage fit into this picture when most digitisation projects are, in one way or another, nationally framed? What biases can digital archives introduce in our work and how does that differ from issues of bias and selection in the ‘paper’ archive? In discussing these questions, I will provide a couple of examples before emphasising the importance of more transparency in this regard and the need for guidelines about how digital archives are constituted. A key point to highlight is that professional historians can and should be more open to learn from the experience of digital archivists and librarians who are at the forefront of the digital turn in heritage work. [less ▲]

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See detailThe Digital Archive and the Politics of Digitisation
Zaagsma, Gerben UL

Presentation (2020, February 13)

This paper deals with a question that is becoming increasingly important for historians who work with digitised cultural heritage: what are the politics of digitisation and what are its implications for ... [more ▼]

This paper deals with a question that is becoming increasingly important for historians who work with digitised cultural heritage: what are the politics of digitisation and what are its implications for historical research? Is the often-lauded democratising potential of digitisation also offset by risks, inherent in selection processes that might privilege the digitisation of heritage corresponding to existing national master narratives, the availability of funding and/or the priorities set by cultural policies and certain research agendas? How does transnational heritage fit into this picture when most digitisation projects are, in one way or another, nationally framed? What biases can digital archives introduce in our work and how does that differ from issues of bias and selection in the ‘paper’ archive? In discussing these questions, I will provide a couple of examples before emphasising the importance of more transparency in this regard and the need for guidelines about how digital archives are constituted. A key point to highlight is that professional historians can and should be more open to learn from the experience of digital archivists and librarians who are at the forefront of the digital turn in heritage work. [less ▲]

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See detailDigital Asset Funds
Zetzsche, Dirk Andreas UL; Consiglio, Roberta UL; Lore, J.

in The AIFM Directive (2020)

Detailed reference viewed: 40 (0 UL)