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See detailShear Transfer in Heavy Steel-Concrete Composite Columns with Multiple Encased Steel Profiles
Chrzanowski, Maciej UL

Doctoral thesis (2019)

The PhD Thesis is dealing with the shear transfer in heavy steel-concrete composite columns with multiple encased steel profiles. In the conducted research, a focus was placed on two aspects of shear ... [more ▼]

The PhD Thesis is dealing with the shear transfer in heavy steel-concrete composite columns with multiple encased steel profiles. In the conducted research, a focus was placed on two aspects of shear transfer: (1) local shear transfer at the steel-concrete interface and (2) global shear transfer between the embedded steel profiles. With reference to the current practice, gaps in the knowledge and in the available solutions have been identified. The development of a novel, easy-applicable and efficient type of shear connectors for an application in composite columns with one or multiple-encased steel profiles satisfies the improvement need to assure local shear transfer between steel and concrete materials. The novel type of flat shear connectors has a form of reinforcement bars welded to the flanges of steel profiles. Three main orientations, in accordance to the steel beam longitudinal axis, were investigated: 1) transversal, 2) longitudinal and 3) angled under 45° - V-shaped. The force transfer mechanism of the proposed shear connectors considers the usage of the external stirrups to anchorage the compression struts and bear the tensile forces. In parallel, the steel-concrete bond phenomenon was examined and analysed. In the consideration of the global shear transfer and in respect to the mechanical engineering model and behaviour of large composite columns with more than one embedded steel profile, the common practice so far is to assume a homogenous system with one stiffness and analyse it based on the Bernoulli beam theory. However, the results of the recent tests caused some doubts whether this approach is correct. The derivation away from the Bernoulli beam behaviour leads to a changed stiffness of the column and hence changed critical buckling load. An innovative hybrid conception has been proposed, where a transition towards the Vierendeel truss model embedded into the Timoshenko beam model is considered in order to govern the identified significant effects of shear deformation. Within this objective, big-scale beam/column members with two embedded steel profiles were examined in order to investigate an internal forces distribution and its bending and shear stiffness. A complex interaction between the materials and lack of knowledge regarding composite behaviour in columns with multiple encased steel profiles opens opportunities to develop novel systems and design methods. The described objectives are investigated experimentally and by the FE numerical simulations. As an outcome, an analytical model for the resistance of the developed novel shear connectors and innovative mechanical engineering model for the description of the structural behaviour, as well as effective stiffness, of a composite member with more than one embedded steel profile are given. [less ▲]

Detailed reference viewed: 333 (41 UL)
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See detailSheaves and D-modules on Lorentzian manifolds
Schapira, Pierre UL; Jubin, Benoît Michel UL

E-print/Working paper (2015)

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See detailA Sheffer-criterion for partial 4-valued logic
Schölzel, Karsten UL

in Journal of Multiple-Valued Logic and Soft Computing (2012), 18(2), 167-199

We determine the minimal covering of maximal partial clones in 4-valued logic. That means a necessary and sufficient condition for partial Sheffer functions in 4-valued logic in terms of the maximal ... [more ▼]

We determine the minimal covering of maximal partial clones in 4-valued logic. That means a necessary and sufficient condition for partial Sheffer functions in 4-valued logic in terms of the maximal partial clones is established. Furthermore several statements about members of the minimal covering of the maximal partial clones for any finite-valued logic are established. [less ▲]

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See detailShelf Life and Controlled Cure of Epoxies by Loaded Zeolite
Gaukler, J. Ch; Müller, Ulrich UL; Krüger, Jan-Kristian UL et al

in Composite Interfaces (2010)

Epoxy formulations based on the multi-functional amine hardener, dicyandiamide (Dicy), regularly contain a free accelerator for reducing the curing temperature and the time needed to complete the network ... [more ▼]

Epoxy formulations based on the multi-functional amine hardener, dicyandiamide (Dicy), regularly contain a free accelerator for reducing the curing temperature and the time needed to complete the network formation. Unfortunately, all accelerators reduce the shelf life of these adhesives at 25◦C. In order to solve this problem, accelerator-loaded zeolites fillers were developed, optimised with respect to host–guest interactions and characterised by Fraunhofer IFAM (Bremen, Germany) with regard to the release and curing behaviour in epoxy adhesive formulations. They are added to an epoxy adhesive (diglycidylether of bisphenol A (EP) and dicyandiamide (Dicy), mass ratio 100:6.7), stored at 25◦C in regular air or cured (heated with β = 10 K/min to 170◦C subsequent isothermal curing for 45 min). That shelf life and curing behaviour are investigated by FT-IR spectroscopy and modulated DSC. Compared to the EP containing free accelerator, the zeolite-filled EP possesses a threefold increase in shelf life at 25◦C due to the immobilization of the accelerator in the pores of the zeolites. While the free accelerator acts steadily during heating, it is shown that the loaded zeolite releases the accelerator at about 76◦C. Surprisingly, the released accelerator is not only involved in the chemical formation of the epoxy network but it accelerates the dissolution of Dicy considerably. As the result, network formation at 170◦C finishes after not more than 19 min and the starting temperature for curing could be reduced to 140◦C. [less ▲]

Detailed reference viewed: 156 (0 UL)
See detailShenzhen Biennial
Koolhaas, Charlie; Miessen, Markus UL

Book published by Shenzhen Press Group (2007)

Charlie Koolhaas was the co-curator of the Shenzhen Biennale of Urbanism and Architecture 2007, curated by MADA SPAM, in Shenzhen, China. The city of Shenzhen is the central subject and inspiration of ... [more ▼]

Charlie Koolhaas was the co-curator of the Shenzhen Biennale of Urbanism and Architecture 2007, curated by MADA SPAM, in Shenzhen, China. The city of Shenzhen is the central subject and inspiration of this exhibition. In her role, as curator Charlie also acted as Art Director of the two Biennale catalogs, which she then developed into text based installations that were spread throughout the exhibition space. Charlie also contributed two photographic installations to the exhibit. The first was visual research called 'green and grey', which investigated the relationship between nature and human life in the lush, tropical city of Shenzhen that is experiencing rapid development. The second installation called 'Dead London' showed photographs of the post-industrial area of East-London, UK. [less ▲]

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See detailA shift in paradigm towards human biology-based systems for cholestatic-liver diseases.
Noor, Fozia UL

in The Journal of physiology (2015), 593(23), 5043-55

Cholestatic-liver diseases (CLDs) arise from diverse causes ranging from genetic factors to drug-induced cholestasis. The so-called diseases of civilization (obesity, diabetes, metabolic disorders, non ... [more ▼]

Cholestatic-liver diseases (CLDs) arise from diverse causes ranging from genetic factors to drug-induced cholestasis. The so-called diseases of civilization (obesity, diabetes, metabolic disorders, non-alcoholic liver disease, cardiovascular diseases, etc.) are intricately implicated in liver and gall bladder diseases. Although CLDs have been extensively studied, there seem to be important gaps in the understanding of human disease. Despite the fact that many animal models exist and substantial clinical data are available, translation of this knowledge towards therapy has been disappointingly limited. Recent advances in liver cell culture such as in vivo-like 3D cultivation of human primary hepatic cells, human induced pluripotent stem cell-derived hepatocytes; and cutting-edge analytical techniques such as 'omics' technologies and high-content screenings could play a decisive role in deeper mechanistic understanding of CLDs. This Topical Review proposes a roadmap to human biology-based research using omics technologies providing quantitative information on mechanisms in an adverse outcome/disease pathway framework. With modern sensitive tools, a shift in paradigm in human disease research seems timely and even inevitable to overcome species barriers in translation. [less ▲]

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See detailShift-symmetric configurations in two-dimensional cellular automata: Irreversibility, insolvability, and enumeration
Banda, Peter UL; Caughman, John; Cenek, Martin et al

in Chaos (2019), 29(6), 063120

The search for symmetry as an unusual yet profoundly appealing phenomenon, and the origin of regular, repeating configuration patterns have long been a central focus of complexity science and physics. To ... [more ▼]

The search for symmetry as an unusual yet profoundly appealing phenomenon, and the origin of regular, repeating configuration patterns have long been a central focus of complexity science and physics. To better grasp and understand symmetry of configurations in decentralized toroidal architectures, we employ group-theoretic methods, which allow us to identify and enumerate these inputs, and argue about irreversible system behaviors with undesired effects on many computational problems. The concept of so-called configuration shift-symmetry is applied to two-dimensional cellular automata as an ideal model of computation. Regardless of the transition function, the results show the universal insolvability of crucial distributed tasks, such as leader election, pattern recognition, hashing, and encryption. By using compact enumeration formulas and bounding the number of shift-symmetric configurations for a given lattice size, we efficiently calculate the probability of a configuration being shift-symmetric for a uniform or density-uniform distribution. Further, we devise an algorithm detecting the presence of shift-symmetry in a configuration. Given the resource constraints, the enumeration and probability formulas can directly help to lower the minimal expected error and provide recommendations for system’s size and initialization. Besides cellular automata, the shift-symmetry analysis can be used to study the non-linear behavior in various synchronous rule-based systems that include inference engines, Boolean networks, neural networks, and systolic arrays. [less ▲]

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See detailShifting Epistemologies for Discipline and Rigour in Educational Research: Challenges and Opportunities from Digital Humanities
Priem, Karin UL; Fendler, Lynn

in European Educational Research Journal (2019)

This paper historicizes “rigour”, discipline” and “systematic” as inventions of a certain rational spirit of Enlightenment that was radicalized during the 19th century. These terms acquired temporary ... [more ▼]

This paper historicizes “rigour”, discipline” and “systematic” as inventions of a certain rational spirit of Enlightenment that was radicalized during the 19th century. These terms acquired temporary value in a transition during the 19th century when a culture of research was established within a modern episteme. Beginning in the 20th century, this development was perceived as problematic, triggering criticism from philosophy and the arts, and even within the sciences. “Discipline”, “rigour” and “systematic” have changed meanings over time, and recent contributions from Digital Humanities are promising for a renewed critical debate about rigour in research. Both digital humanities and quantitative research deal with big data sets aimed at providing a large-scale analysis. However, unlike most quantitative research, digital humanities explore uncertainties as their main focus. Attention to the human-machine collaboration has led to more expansive thinking in scientific research. Digital humanities go further by advancing a metaperspective that deals with the material hermeneutics of data accumulation itself. [less ▲]

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See detailShifting Load through Space : the Economics of Spatial Demand Side Management Using Distributed Data Centers
Fridgen, Gilbert UL; Keller, Robert; Thimmel, Markus et al

in Energy Policy (2017)

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See detailShifting Martingale Measures and the Birth of a Bubble as a Submartingale
Föllmer, Hans UL; Biagini, Francesca; Nedelcu, Sorin

in Finance and Stochastics (2014), 18(2), 297-326

In an incomplete financial market model, we study a flow in the space of equivalent martingale measures and the corresponding shifting perception of the fundamental value of a given asset. This allows us ... [more ▼]

In an incomplete financial market model, we study a flow in the space of equivalent martingale measures and the corresponding shifting perception of the fundamental value of a given asset. This allows us to capture the birth of a perceived bubble and to describe it as an initial submartingale which then turns into a supermartingale before it falls back to its initial value zero. [less ▲]

Detailed reference viewed: 127 (6 UL)
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See detailShifting perspective on the migration and development nexus in the context of the European Union : From the migration management approach to the development paradigm of mobility?
Silga, Janine UL

in Podstawa, Karolina; Puccio, Laura (Eds.) Framework for Economic Development in EU External Relations (2012)

Detailed reference viewed: 54 (1 UL)
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See detailThe Shifting Relationship between Vocational and Higher Education in France and Germany: Towards Convergence?
Powell, Justin J W UL; Graf, Lukas UL; Bernhard, Nadine et al

in European Journal of Education (2012), 47(3), 405-423

For decades, the skill formation systems in France and Germany have been analysed as contrasting cases because of institutionalised differences in educational values, norms, and governance, as well as in ... [more ▼]

For decades, the skill formation systems in France and Germany have been analysed as contrasting cases because of institutionalised differences in educational values, norms, and governance, as well as in labour markets. This comparison follows the logic of difference, comparing dissimilar skill formation systems in centralist France and federalist Germany. Cross-national variance has often been explained in terms of the institutionalization of vocational education, but higher education also differs considerably. Many typologies of vocational education and training (VET) and higher education (HE) summarise these differences. However, not only are national skill formation systems affected by the emerging European model of education via the Bologna and Copenhagen Processes, but the French and German political economies have also been greatly reconfigured in the last two decades. Comparing the present situation, we ask whether traditional education and training typologies continue to be valid. While they have served as useful heuristic devices, they may hinder recognition of contemporary institutional changes, especially incremental changes that may nevertheless be transformational because of endogenous reforms and exogenous pressures due to Europeanisation. Do these typologies continue to reflect these systems as they evolve? To what extent have the key characteristics of skill formation systems in France and Germany changed, exemplified in the relationship between VET and HE? Have these countries converged? [less ▲]

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See detailThe Shifting Sands of Space Security: The Politics and Law of the Peaceful Uses of Outer Space
Blount, Percy UL

in Indonesian Journal of International Law (2019), 17

Detailed reference viewed: 31 (0 UL)
See detailShifting Sounds: Textualization and Dramatization of Urban Soundscapes
Bijsterveld, Karin; Jacobs, Annelies; Aalbers, Jasper et al

in Bijsterveld, Karin (Ed.) Soundscapes of the Urban Past: Staged Sound as Mediated Cultural Heritage (2013)

Detailed reference viewed: 322 (9 UL)
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See detailShifts and Twists in the Relative Productivity of Skilled Workers
Dupuy, Arnaud UL; Marey, Philip

in Journal of Macroeconomics (2008)

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See detailShifts of spatial attention cued by irrelevant numbers: Electrophysiological evidence from a target discrimination task
Schuller, Anne-Marie UL; Hoffmann, Danielle UL; Goffaux, Valérie et al

in Journal of Cognitive Psychology (2014)

Fischer et al. demonstrated that a centrally presented number can shift attention to the left/right when its magnitude is small/large. Two electrophysiological studies described these attentional effects ... [more ▼]

Fischer et al. demonstrated that a centrally presented number can shift attention to the left/right when its magnitude is small/large. Two electrophysiological studies described these attentional effects as eventrelated potentials (ERPs) at centro-parietal sites. Since both studies used target detection tasks, it remains currently unknown whether similar results would be obtained with a discrimination task. We used ERPs to test whether digit cues also induce attention shifts when participants perform a feature discrimination task on targets. ERPs were recorded whereas subjects discriminated the colour of lateral targets that were preceded by a central non-predictive digit. Analysis of cue-locked controlateral vs. ipsilateral ERP activity showed the emergence of early preparatory attention-directing components in parietal and frontal regions. Moreover, target-locked P1 components at occipito-parietal sites were significantly modulated by digit magnitude-target side congruency. These results demonstrate that irrelevant digit cues also bias sensory processing when embedded in a feature-discrimination task. [less ▲]

Detailed reference viewed: 296 (20 UL)
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See detailShifts of spatial attention cued by irrelevant numbers: Electrophysiological evidence from a target discrimination task
Schuller, Anne-Marie UL; Hoffmann, Danielle UL; Schiltz, Christine UL

Poster (2012, February 10)

Fischer et al. demonstrated that a centrally presented number can shift attention to the left/right when its magnitude is small/large. Two electrophysiological studies described these attentional effects ... [more ▼]

Fischer et al. demonstrated that a centrally presented number can shift attention to the left/right when its magnitude is small/large. Two electrophysiological studies described these attentional effects as event-related potentials (ERPs) at centro-parietal sites. Since both studies used target detection tasks, it remains currently unknown whether similar results would be obtained with a discrimination task. We used ERPs to test whether digit cues also induce attention shifts when participants perform a feature-discrimination task on targets. ERPs were recorded whereas subjects discriminated the colour of lateral targets that were preceded by a central non-predictive digit. Analysis of cue-locked controlateral vs. ipsilateral ERP activity showed the emergence of early preparatory attention-directing components in parietal and frontal regions. Moreover, target-locked P1 components at occipito-parietal sites were significantly modulated by digit magnitude-target side congruency. These results demonstrate that irrelevant digit cues also bias sensory processing when embedded in a feature-discrimination task. [less ▲]

Detailed reference viewed: 115 (0 UL)
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See detailShifts of spatial attention cued by irrelevant numbers: Electrophysiological evidence from a target discrimination task
Schuller, Anne-Marie UL; Hoffmann, Danielle UL; Schiltz, Christine UL

Poster (2011, April)

Fischer et al. demonstrated that a centrally presented number can shift attention to the left/right when its magnitude is small/large. Two electrophysiological studies described these attentional effects ... [more ▼]

Fischer et al. demonstrated that a centrally presented number can shift attention to the left/right when its magnitude is small/large. Two electrophysiological studies described these attentional effects as event-related potentials (ERPs) at centro-parietal sites. Since both studies used target detection tasks, it remains currently unknown whether similar results would be obtained with a discrimination task. We used ERPs to test whether digit cues also induce attention shifts when participants perform a feature-discrimination task on targets. ERPs were recorded whereas subjects discriminated the colour of lateral targets that were preceded by a central non-predictive digit. Analysis of cue-locked controlateral vs. ipsilateral ERP activity showed the emergence of early preparatory attention-directing components in parietal and frontal regions. Moreover, target-locked P1 components at occipito-parietal sites were significantly modulated by digit magnitude-target side congruency. These results demonstrate that irrelevant digit cues also bias sensory processing when embedded in a feature-discrimination task. [less ▲]

Detailed reference viewed: 138 (3 UL)
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See detailShifts of spatial attention cued by irrelevant numbers: electrophysiological evidence.
Schuller, Anne-Marie UL

in Journal of Cognitive Neuroscience (2011)

Detailed reference viewed: 70 (5 UL)