| 44811. |
- Kunets, Y. I., et al.
(författare)
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Scattering of a SH-wave by an elastic fiber of nonclassical cross section with an interface crack
- 2008
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Ingår i: Mechanics of Composite Materials. - : Springer Science and Business Media LLC. - 0191-5665 .- 1573-8922. ; 44:2, s. 165-172
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Tidskriftsartikel (refereegranskat)abstract
- The problem of interaction of a plane time-harmonic SH-wave with an elastic fiber of quasi-square or quasi-triangular cross section, when an interface crack is present between an infinite elastic matrix and the fiber, is considered. The modified null-field method taking into account the asymptotic behavior of the solution at crack tips is exploited for obtaining numerical results. The effects of fiber shape, fiber/matrix material combination, debonding (crack size), and direction of wave incidence on the scattering amplitude in the far field are analyzed.
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| 44812. |
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| 44813. |
- Künsch, Hans R., et al.
(författare)
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Optimal lattices for sampling
- 2005
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Ingår i: IEEE Transactions on Information Theory. - 0018-9448 .- 1557-9654. ; 51:2, s. 634-647
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Tidskriftsartikel (refereegranskat)abstract
- The generalization of the sampling theorem to multidimensional signals is considered, with or without bandwidth constraints. The signal is modeled as a stationary random process and sampled on a lattice. Exact expressions for the mean-square error of the best linear interpolator are given in the frequency domain. Moreover, asymptotic expansions are derived for the average mean-square error when the sampling rate tends to zero and infinity, respectively. This makes it possible to determine the optimal lattices for sampling. In the low-rate sampling case, or equivalently for rough processes, the optimal lattice is the one which solves the packing problem, whereas in the high-rate sampling case, or equivalently for smooth processes, the optimal lattice is the one which solves the dual packing problem. In addition, the best linear interpolation is compared with ideal low-pass filtering (cardinal interpolation).
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| 44814. |
- Kunstelj, K, et al.
(författare)
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Switching of Electrically Commanded Alignment Layers Probed by Optical Second Harmonic Generation
- 2006
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Ingår i: Molecular Crystals and Liquid Crystals. - : Informa UK Limited. - 1563-5287 .- 1542-1406 .- 1058-7276. ; 450:1, s. 127/[327] - 139/[339]
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Tidskriftsartikel (refereegranskat)abstract
- Optical second harmonic generation (SHG) was used to probe the response of a 200 nm thick electrically commanded alignment layer made of ferroelectric liquid crystal polymer (FLCP) film to an external DC electric field. The results show that for the field magnitudes in the range 0-2 V/ m the field induced reorientation effects represent only a relatively minor structural perturbation of the film. The switching process is monostable and shows characteristics of the "V-shaped" switching. The response time of the SHG signal is relatively longer than what is measured for the bulk FLCP. Several mechanisms are considered as possible reasons for that.
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| 44815. |
- Kuntrapakam, Hema, et al.
(författare)
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Guest Encapsulation Alters the Thermodynamic Landscape of a Coordination Host
- 2023
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Ingår i: Journal of the American Chemical Society. - 1520-5126 .- 0002-7863. ; 145:45, s. 24755-24764
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Tidskriftsartikel (refereegranskat)abstract
- The architecture of self-assembled host molecules can profoundly affect the properties of the encapsulated guests. For example, a rigid cage with small windows can efficiently protect its contents from the environment; in contrast, tube-shaped, flexible hosts with large openings and an easily accessible cavity are ideally suited for catalysis. Here, we report a “Janus” nature of a Pd6L4 coordination host previously reported to exist exclusively as a tube isomer (T). We show that upon encapsulating various tetrahedrally shaped guests, T can reconfigure into a cage-shaped host (C) in quantitative yield. Extracting the guest affords empty C, which is metastable and spontaneously relaxes to T, and the T⇄C interconversion can be repeated for multiple cycles. Reversible toggling between two vastly different isomers paves the way toward controlling functional properties of coordination hosts “on demand”.
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| 44816. |
- Kunz, Andreas, et al.
(författare)
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Collaborative Whiteboard: Towards Remote CollaBoration and Interaction in Construction Design
- 2010
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Ingår i: Proc. 27th International Conference on Applications of IT in the ABC Industry & Accelerating BIM Research Workshop. ; , s. 132-140
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Konferensbidrag (refereegranskat)abstract
- The need for improved collaboration and interaction in construction projects has grown significantly in recent years, especially as projects have become ever more complex. The early design stage is of particular importance for the final results as most of the building’s lifecycle characteristics are committed at this stage, and the opportunity to influence them decreases rapidly as the cost of making changes, or correcting design errors, increases dramatically. Recent advances in information technology offer methods and tools to meet this need. In view of this, a collaborative whiteboard (CollaBoard) for remote collaboration – is being developed to support mixed, geographically distributed teams. Interconnected via a network, two or more system setups allow users to interact and share information over a common, interactive vertical whiteboard, allowing experts from different disciplines access to databases through intuitive interfaces in order to integrate and optimize lifecycle-related parameters into a new product. Superimposing the live video of the remote partner – “people on content” – also allows the transfer of meta information, such as gestures, resulting in more intuitively distributed collaborative teamwork.
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| 44817. |
- Kunz, Andreas, et al.
(författare)
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From Table–System to Tabletop: Integrating Technology into Interactive Surfaces
- 2010
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Ingår i: Tabletops - Horizontal Interactive Displays. - London : Springer London. ; , s. 53-72
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Teamwork for generating new ideas is typically done on vertical or horizontal interaction spaces in order to capture volatile ideas by generating digital content that can be used during ongoing work. While many products are available for vertical interaction spaces, tabletop interaction is still subject to ongoing research and development. The following article gives a classification of existing tabletop systems according to the type of interaction, the means of tracking and identification, and the method of displaying images. Then, the challenges faced by researchers and the motivations behind their endeavors are discussed. We describe the evolution of this technology by citing important projects and their significance in the overall development of interactive tabletop surfaces. Finally, we give an outlook on future trends in this research field.
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| 44818. |
- Kunz, Anne, et al.
(författare)
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Intermolecular London Dispersion Interactions of Azobenzene Switches for Tuning Molecular Solar Thermal Energy Storage Systems
- 2019
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Ingår i: ChemPlusChem. - : Wiley. - 2192-6506. ; 84:8, s. 1145-1148
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Tidskriftsartikel (refereegranskat)abstract
- The performance of molecular solar thermal energy storage systems (MOST) depends amongst others on the amount of energy stored. Azobenzenes have been investigated as high-potential materials for MOST applications. In the present study it could be shown that intermolecular attractive London dispersion interactions stabilize the (E)-isomer in bisazobenzene that is linked by different alkyl bridges. Differential scanning calorimetry (DSC) measurements revealed, that this interaction leads to an increased storage energy per azo-unit of more than 3 kcal/mol compared to the parent azobenzene. The origin of this effect has been supported by computation as well as X-ray analysis. In the solid state structure attractive London dispersion interactions between the C−H of the alkyl bridge and the π-system of the azobenzene could be clearly assigned. This concept will be highly useful in designing more effective MOST systems in the future.
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| 44819. |
- Kunz, Andreas, et al.
(författare)
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Multistatus Interaktionsgeräte für interaktive Tische
- 2013
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Ingår i: icom. - 1618-162X. ; 12:1, s. 39-44
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Tidskriftsartikel (refereegranskat)abstract
- This article introduces a procedure and a prototype that allow using multiple interactive devices on an interactive tabletop without reducing the system‘s overall responsiveness. Furthermore, the active interaction devices could transfer their individual state to the system using a multi-digit bit word. This allows entering additional information with a high resolution.
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| 44820. |
- Kunz, Andreas, et al.
(författare)
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Real walking in virtual environments for factory planning and evaluation
- 2016
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Ingår i: Procedia CIRP. - : Elsevier BV. - 2212-8271. ; 44, s. 257-262
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Konferensbidrag (refereegranskat)abstract
- Nowadays, buildings or production facilities are designed using specialized design software and building information modeling tools help to evaluate the resulting virtual mock-up. However, with current, primarily desktop based tools it is hard to evaluate human factors of such a design, for instance spatial constraints for workforces. This paper presents a new tool for factory planning and evaluation based on virtual reality that allows designers, planning experts, and workforces to walk naturally and freely within a virtual factory. Therefore, designs can be checked as if they were real before anything is built.
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