TY - JOUR A1 - Maleki, Maniya A1 - Mohammadi, Mahdieh T1 - Velocity and pressure functions of an oscillating flow in a circular Hele-Shaw cell JF - Iranian Journal of Physics Research N2 - In this study, we have investigated the form of velocity and pressure functions of a fluid oscillating between two parallel glass sheets that form a circular Hele-Shaw cell. The flow has been considered to be radial, incompressible and laminar. The time-dependent Navier-Stokes equation has been solved in cylindrical coordinates using Fourier transform, and the oscillating flow velocity across the thickness of the cell has been obtained at different times. The flow velocity function in the unsteady state is related to the vertical component of the coordinates in the form of parabolic functions and also to the inverse of the radial component. The time dependence appears as a simple harmonic with a frequency equal to the oscillation frequency. The velocity of the flow is maximum at the middle of the cell along its height and gradually decreases from the middle towards the top or bottom plane and reaches zero. Pressure does not depend on the height and changes logarithmically with the radius. The dependence of pressure on time is also a simple harmonic with the external frequency, but it has a phase shift with respect to the velocity. Y1 - 2023 U6 - https://doi.org/10.47176/ijpr.22.1.81304 VL - 22 IS - 1 SP - 113 EP - 120 PB - Physics Society of Iran ER - TY - JOUR A1 - Lachowski, Krzysztof A1 - Hammermeister, Florian A1 - Halenz, Bastian A1 - Lieckefett, Florian A1 - Götze, Thomas A1 - Prill, Robert A1 - Becker, Roland T1 - The Patellostabilometer: A New Device for Quantification of Mediolateral Patella Displacement JF - Sensors N2 - Mediolateral patella displacement is of interest for diagnostics and clinically relevant research questions. Apart from manual testing, no standardized method is currently available. Proper quantification of patella mobility is necessary to better understand pathologies at the patellofemoral joint. Patella mobility was assessed in 25 healthy individuals using a Patellostabilometer, a new prototype instrument for quantification of the mediolateral patella displacement. The participants underwent measurements of the mediolateral displacement three times using the Patellostabilome- ter. A maximal force of 10 N was applied for patella movement. Additionally, leg length and circumference of the knee, upper- and lower-leg were measured. Lateral patella displacement of 18.27 ± 3.76 mm (range 15.85–20.64 mm, interquartile range (IQR) of 4.79) was measured. The medial patella displacement showed 24.47 ± 6.59 mm (range 19.29–29.76 mm, IQR of 10.47). The test–retest measurement error was 2.32 ± 1.76 mm (IQR of 2.38 mm), with five outliers. There was greater test–retest variability between the measurements of the medial displacement compared to the lateral one. The test–retest variability reached 7% of the patella displacement. Other parameters provided no significant correlations. Based on the natural patellofemoral mobility, a precise and clinically relevant quantification of patella mobility is allowed. Y1 - 2023 UR - https://www.mdpi.com/1424-8220/23/3/1274 U6 - https://doi.org/https://doi.org/10.3390/s23031274 IS - 23 (3) PB - MDPI ER - TY - JOUR A1 - Rizun, Nina A1 - Revina, Aleksandra A1 - Edelmann, Noella T1 - Application of Text Analytics in Public Service Co-Creation: Literature Review and Research Framework JF - DG.O 2023: The 24th Annual International Conference on Digital Government Research N2 - The public sector faces several challenges, such as a number of external and internal demands for change, citizens' dissatisfaction and frustration with public sector organizations, that need to be addressed. An alternative to the traditional top-down development of public services is co-creation of public services. Co-creation promotes collaboration between stakeholders with the aim to create better public services and achieve public values. At the same time, data analytics has been fuelled by the availability of immense amounts of textual data. Whilst both co-creation and TA have been used in the private sector, we study existing works on the application of Text Analytics (TA) techniques on text data to support public service co-creation. We systematically review 75 of the 979 papers that focus directly or indirectly on the application of TA in the context of public service development. In our review, we analyze the TA techniques, the public service they support, public value outcomes, and the co-creation phase they are used in. Our findings indicate that the TA implementation for co-creation is still in its early stages and thus still limited. Our research framework promotes the concept and stimulates the strengthening of the role of Text Analytics techniques to support public sector organisations and their use of co-creation process. From policy-makers' and public administration managers' standpoints, our findings and the proposed research framework can be used as a guideline in developing a strategy for the designing co-created and user-centred public services. Y1 - 2023 UR - https://dl.acm.org/doi/10.1145/3598469.3598471 U6 - https://doi.org/10.1145/3598469.3598471 SP - 12 EP - 22 PB - Association for Computing Machinery ER - TY - JOUR A1 - Guterding, Daniel T1 - Sparse Modeling Approach to the Arbitrage-Free Interpolation of Plain-Vanilla Option Prices and Implied Volatilities JF - Risks N2 - We present a method for the arbitrage-free interpolation of plain-vanilla option prices and implied volatilities, which is based on a system of integral equations that relates terminal density and option prices. Using a discretization of the terminal density, we write these integral equations as a system of linear equations. We show that the kernel matrix of this system is, in general, ill-conditioned, so that it cannot be solved for the discretized density using a naive approach. Instead, we construct a sparse model for the kernel matrix using singular value decomposition (SVD), which allows us not only to systematically improve the condition number of the kernel matrix, but also determines the computational effort and accuracy of our method. In order to allow for the treatment of realistic inputs that may contain arbitrage, we reformulate the system of linear equations as an optimization problem, in which the SVD-transformed density minimizes the error between the input prices and the arbitrage-free prices generated by our method. To further stabilize the method in the presence of noisy input prices or arbitrage, we apply an 𝐿1-regularization to the SVD-transformed density. Our approach, which is inspired by recent progress in theoretical physics, offers a flexible and efficient framework for the arbitrage-free interpolation of plain-vanilla option prices and implied volatilities, without the need to explicitly specify a stochastic process, expansion basis functions or any other kind of model. We demonstrate the capabilities of our method in a number of artificial and realistic test cases. Y1 - 2023 UR - https://www.mdpi.com/2227-9091/11/5/83 U6 - https://doi.org/https://doi.org/10.3390/risks11050083 IS - 11 (5) PB - MDPI AG ER - TY - JOUR A1 - Stannarius, Ralf A1 - Harth, Kirsten T1 - The structure of disintegrating defect clusters in smectic C freely suspended films JF - Soft Matter N2 - Disclinations or disclination clusters in smectic C freely suspended films with topological charges larger than one are unstable. They disintegrate, preferably in a spatially symmetric fashion, into single defects with individual charges of +1, which is the smallest positive topological charge allowed in polar vector fields. While the opposite process of defect annihilation is well-defined by the initial defect positions, disintegration starts from a singular state and the following scenario including the emerging regular defect patterns must be selected by specific mechanisms. We analyze experimental data and compare them with a simple model where the defect clusters adiabatically pass quasi-equilibrium solutions in one-constant approximation. It is found that the defects arrange in geometrical patterns that correspond very closely to superimposed singular defect solutions, without additional director distortions. The patterns expand by affine transformations where all distances between individual defects scale with the same time-dependent scaling factor proportional to the square-root of time. Y1 - 2023 UR - https://pubs.rsc.org/en/content/articlelanding/2023/sm/d3sm00808h U6 - https://doi.org/https://doi.org/10.1039/d3sm00808h IS - 19 SP - 6109 EP - 6115 PB - Royal Society of Chemistry ER - TY - JOUR A1 - Xu, Han-Xiang A1 - Shimizu, Makoto A1 - Guterding, Daniel A1 - Otsuki, Junya A1 - Jeschke, Harald O. T1 - Pressure evolution of electronic structure and magnetism in the layered van der Waals ferromagnet CrGeTe3 JF - Physical Review B N2 - Layered van der Waals ferromagnets, which preserve their magnetic properties down to exfoliated monolayers, are fueling an abundance of fundamental research and nanoscale device demonstration. CrGeTe3 is a prime example of this class of materials. Its temperature-pressure phase diagram features an insulator-to-metal transition and a significant increase in ferromagnetic Curie-Weiss temperatures upon entering the metallic state. We use density functional theory to understand the magnetic exchange interactions in CrGeTe3 at ambient and elevated pressures. We calculate Heisenberg exchange couplings, which provide the correct ferromagnetic ground state and explain the experimentally observed pressure dependence of magnetism in CrGeTe3. Furthermore, we combine density functional theory with dynamical mean-field theory to investigate the effects of electronic correlations and the nature of the high-pressure metallic state in CrGeTe3. Y1 - 2023 U6 - https://doi.org/https://doi.org/10.1103/PhysRevB.108.125142 IS - Vol. 108 PB - American Physical Society ER - TY - JOUR A1 - Klopp, Christoph A1 - Trittel, Torsten A1 - Harth, Kirsten A1 - Stannarius, Ralf T1 - Coalescence of biphasic droplets embedded in free standing smectic A films JF - Soft Matter N2 - We investigate micrometer-sized flat droplets consisting of an isotropic core surrounded by a nematic rim in freely suspended smectic A liquid-crystal films. In contrast to purely isotropic droplets which are characterized by a sharp edge and no long-range interactions, the nematic fringe introduces a continuous film thickness change resulting in long-range mutual attraction of droplets. The coalescence scenario is divided in two phases. The first one consists in the fusion of the nematic regions. The second phase involves the dissolution of a thin nematic film between the two isotropic cores. The latter has many similarities with the rupture of thin liquid films between droplets coalescing in an immiscible viscous liquid. Coalescence of biphasic droplets in free-standing smectic films is controlled in part by the rupture of a thin nematic membrane separating the isotropic droplet cores. Y1 - 2023 UR - https://pubs.rsc.org/en/content/articlelanding/2024/sm/d3sm01549a U6 - https://doi.org/10.1039/d3sm01549a SN - 1744-683X VL - 20 IS - 5 SP - 1036 EP - 1046 PB - Royal Society of Chemistry ER - TY - JOUR A1 - Nagel, Michael A1 - Schminder, Christian ED - Erich Schmidt Verlag, T1 - Sachbezogenes Verhandeln als Methode im Zielbildungsprozess von innovationsorientierten Public Private Partnerships. JF - Ideen- und Innovationsmanagement Y1 - 2023 U6 - https://doi.org/10.37307/j.2198-3151.2022.02.07 SN - 2198-3151 IS - 2 SP - 72 EP - 77 PB - Erich Schmidt Verlag GmbH & Co ER - TY - JOUR A1 - Johannsen, Andreas T1 - ERP-Einführung - Bewertung einer Standardimplementierungsmethode für SAP Business One JF - ERP Management Y1 - 2023 SN - 1860-6725 SP - 19 EP - 22 PB - GITO Verlag ER - TY - JOUR A1 - Kuznetsov, Arthur A1 - Frorip, Aleksandr A1 - Sünter, Alar A1 - Kasvand, Nensi A1 - Korsakov, Vadim A1 - Konoplev, Georgii A1 - Stepanova, Oksana A1 - Rusalepp, Linda A1 - Anton, Dea A1 - Püssa, Tõnu A1 - Roasto, Mati A1 - Abramova, Liubov A1 - Kozin, Andrey A1 - Toom, Lauri A1 - Hirsch, Sören A1 - Mukhin, Nikolay ED - mdpi, T1 - Fast Protein and Metabolites (Nucleotides and Nucleosides) Liquid Chromatography Technique and Chemical Sensor for the Assessment of Fish and Meat Freshness JF - Chemosensors N2 - Fast protein and metabolite liquid chromatography (FPLMC) was introduced years ago to enable the easy separation of high-molecular compounds such as proteins from small molecules and the identification of the low-molecular substances. In this paper, the method is applied for the rapid evaluation of freshness and monitoring the aging of animal meat and fish. A novel chromatographic sensor was developed with a deep UV LED-based photometric detection unit (255–265 nm), an original flow cuvette and registration scheme; the processing of a chromatogram with the sensor takes approximately 15 min. Strict isochronism between the elution of ATP metabolites, mainly hypoxanthine (Hx) and inosine monophosphate (IMP), and the time of maturation of meat or fish, was discovered. A new freshness index H* = [Hx]/[IMP] was introduced, which is proportional to the instrumental delay time in the FPMLC chromatograms: the H* index < 0.5 indicates the presence of inosine monophosphate (IMP) and the high quality of the meat or fish. Reasonably strong correlations were revealed between data obtained by FPMLC and total volatile basic nitrogen TVB-N (for fish) or volatile fatty acids VFA (for meat) content. Moreover, putative nucleotide salvage and an increase in the concentration of IMP were observed in fish after heat treatment using the FPMLC sensor and NMR technique. Y1 - 2023 UR - https://www.mdpi.com/2227-9040/11/1/69 U6 - https://doi.org/10.3390/chemosensors11010069 SN - 2227-9040 IS - 1/2023 / Band 11 PB - MDPI ER -