Journal articles on the topic 'Dimensionality and ordering'
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Kassan-Ogly, Felix, and Alexey Proshkin. "Frustrations and phase transitions in magnets of various dimensionality." EPJ Web of Conferences 185 (2018): 11002. http://dx.doi.org/10.1051/epjconf/201818511002.
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We studied magnetic orderings, phase transitions, and frustrations in the Ising, 3-state Potts and standard 4-state Potts models on 1D, 2D, and 3D lattices: linear chain, square, triangular, kagome, honeycomb, and body-centered cubic. The main challenge was to find out the causes of frustrations phenomena and those features that distinguish frustrated system from not frustrated ones. The spins may interrelate with one another via the nearest-neighbor, the next-nearest-neighbor or higher-neighbor exchange interactions and via an external magnetic field that may be either competing or not. For problem solving we mainly calculated the entropy and specific heat using the rigorous analytical solutions for Kramers-Wannier transfer-matrix and exploiting computer simulation, par excellence, by Wang-Landau algorithm. Whether a system is ordered or frustrated is depend on the signs and values of exchange interactions. An external magnetic field may both favor the ordering of a system and create frustrations. With the help of calculations of the entropy, the specific heat and magnetic parameters, we obtained the points and ranges of frustrations, the frustration fields and the phase transition points. The results obtained also show that the same exchange interactions my either be competing or noncompeting which depends on the specific model and the lattice topology.
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CORBERI, FEDERICO, NICOLA FUSCO, EUGENIO LIPPIELLO, and MARCO ZANNETTI. "NON-TRIVIAL BEHAVIOR OF THE LINEAR RESPONSE FUNCTION IN PHASE ORDERING KINETICS." International Journal of Modern Physics B 18, no. 04n05 (February 20, 2004): 593–605. http://dx.doi.org/10.1142/s0217979204024215.
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Drawing from exact, approximate and numerical results an overview of the properties of the out of equilibrium response function in phase ordering kinetics is presented. Focusing on the zero field cooled magnetization, emphasis is on those features of this quantity which display non trivial behavior when relaxation proceeds by coarsening. Prominent among these is the dimensionality dependence of the scaling exponent aχ which leads to failure of the connection between static and dynamic properties at the lower dimensionality dL, where aχ=0. We also analyse the mean spherical model as an explicit example of a stochastic unstable system, for which the connection between statics and dynamics fails at all dimensionalities.
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GUNDAKARAM, R., and C. Y. HUANG. "EFFECTS OF DIMENSIONALITY IN THE RARE-EARTH MANGANATES." International Journal of Modern Physics B 13, no. 29n31 (December 20, 1999): 3792–98. http://dx.doi.org/10.1142/s0217979299003945.
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We report measurements of magnetization, magnetoresistance and ESR on systems with the 3-D and layered structures, to study the effect of reduced dimensionality. Compositions of the systems Pr 0.7 Sr 0.3- x Ca x MnO 3 and La 2-2 y Sr 1+2 y Mn 2- z Cr z O 7 were synthesized, which have the 3D and quasi-2D structures, respectively. The magnetic and transport properties are markedly affected by the reduction in dimensionality. Large values of magnetoresistance have been observed in the layered materials even at low temperature, in contrast with the behavior of the 3D compositions. ESR measurements on the Pr 0.7 Sr 0.3- x Ca x MnO 3 system show a single resonance line in the temperature range of our study. However, compositions of the La 2-2 y Sr 1+2 y Mn 2 O 7 system with y =0.3, 0.4 and 0.5 show a complex behavior. As the samples are cooled, a single resonance line is first observed, which can be described by a Lorentzian. Below ~2 T c, for compositions with y =0.3 and 0.4, a complex lineshape evolves, which can be resolved into two Gaussian lines. This crossover in the lineshape indicates a transition from a homogeneous to an inhomogeneous spin system, which can be attributed to the nature of the ferromagnetic ordering between the bilayers. The composition with y =0.5 shows a different behavior, which might be due to the antiferroma.gnetic ordering exhibited by this composition. A detailed analysis of the experiments is presented.
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NOGUERA, CLAUDINE. "INSULATING OXIDES IN LOW DIMENSIONALITY: A THEORETICAL REVIEW." Surface Review and Letters 08, no. 01n02 (February 2001): 121–67. http://dx.doi.org/10.1142/s0218625x01000847.
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In the light of recent studies, we summarize our present theoretical understanding of insulating oxides in low dimensionality, including unsupported clusters, planar or stepped surfaces and ultrathin films. We review the various theoretical approaches, their efficiency in calculating ground and excited state properties, and their applications to the present systems. We discuss the forces at work which determine the atomic structure around under-coordinated atoms (equilibrium geometries of very small clusters, bond lengths, relaxation and rumpling at surfaces), the energetics associated with low dimensionality (surface energies and mean cohesion energy in clusters), the electronic properties, such as electron distribution, magnetic interactions and ordering, and electronic excitations (ionization potentials, electron affinity, quasiparticle spectra, d → d and charge transfer excitations).
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Pisarenko, Tatiana A., Anatoly Frolov, and Galina Kraynova. "Evolution of Structure-Scaling and Magnetic Properties during Thermal Loading of Melt-Spun Fe70Cr15B15(Sn) Alloys." Solid State Phenomena 215 (April 2014): 190–95. http://dx.doi.org/10.4028/www.scientific.net/ssp.215.190.
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We have studied the scaling evolution of the structure and magnetic properties of the melt-spun Fe70Cr15B15(Sn) alloys. The magnetic percolation cluster about the percolation threshold forms at the vitrification stage that is determined by both the kinetics of magnetic and of transport properties and the variation of fractal dimensionality. Alloying by tin of contact surface of ribbon decreases the temperature of the cluster formation. It is shown that the evolution of a fractal ordering affects the kinetics of the physical properties of the alloys. The spectra of fractal dimensionality identify the symmetry character of melt-spun alloys. Fractal dimensionDfis reduced at the increasing complexity of hierarchical system.
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Tokunaga, M., N. Miura, and Y. Moritomo. "High-field Study of Layered Manganites R1/2Sr3/2MnO4 (R = La and Nd)." Australian Journal of Physics 52, no. 2 (1999): 227. http://dx.doi.org/10.1071/p98044.
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We have studied the effects of a magnetic field on the magnetism and transport properties of the layered manganites R1/2Sr3/2MnO4 (R = La and Nd) in pulsed magnetic fields up to 40 T. The R = La crystal shows metamagnetic-like transitions above 30 T, concomitantly with a colossal magnetoresistance (CMR) effect as large as [ρ(0) - ρ(H)]/ρ(H) > 103 with a field of µοH = 38 T at low temperatures. These transitions can be ascribed to the field-induced melting of the real-space ordering of the eg electrons (charge ordering). For the R = Nd crystal, a magnetic field along the c-axis enhances the two-dimensionality in the conductivity. Moreover, we observed metamagnetic-like transitions accompanied by the CMR effects at low temperatures, in spite of the absence of charge ordering.
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TOYOKI, HIROYASU. "PHASE ORDERING SIMULATION OF VECTOR ORDER-PARAMETERS WITHOUT SINGULAR DEFECTS." Modern Physics Letters B 07, no. 06 (March 10, 1993): 397–403. http://dx.doi.org/10.1142/s0217984993000394.
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Cell dynamical study of phase ordering dynamics is presented for vector order-parameter systems without singular defects. The structure factor satisfies the scaling relation; S (k, t) = l (t)2 g(kl(t)), whose tail at kl ≫ 1 is characterized by a single power as g (x) ~ x −χ. The exponent χ is larger than an analytical value χ = d + n where n and d are the dimensionality of order-parameter and space respectively. The characteristic length varies as l (t) ~ t0.5 for n ≥ 4 while the growth for n = 3 is slower than that.
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Cain, Jeffrey D., Amin Azizi, Matthias Conrad, Sinéad M. Griffin, and Alex Zettl. "Layer-dependent topological phase in a two-dimensional quasicrystal and approximant." Proceedings of the National Academy of Sciences 117, no. 42 (October 5, 2020): 26135–40. http://dx.doi.org/10.1073/pnas.2015164117.
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The electronic and topological properties of materials are derived from the interplay between crystalline symmetry and dimensionality. Simultaneously introducing “forbidden” symmetries via quasiperiodic ordering with low dimensionality into a material system promises the emergence of new physical phenomena. Here, we isolate a two-dimensional (2D) chalcogenide quasicrystal and approximant, and investigate their electronic and topological properties. The 2D layers of the materials with a composition close to Ta1.6Te, derived from a layered transition metal dichalcogenide, are isolated with standard exfoliation techniques, and investigated with electron diffraction and atomic resolution scanning transmission electron microscopy. Density functional theory calculations and symmetry analysis of the large unit cell crystalline approximant of the quasicrystal, Ta21Te13, reveal the presence of symmetry-protected nodal crossings in the quasicrystalline and approximant phases, whose presence is tunable by layer number. Our study provides a platform for the exploration of physics in quasicrystalline, low-dimensional materials and the interconnected nature of topology, dimensionality, and symmetry in electronic systems.
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Hall, Andreas, Stefan Adams, and Jan Swenson. "Local dimensionality and intermediate range ordering of ion conduction pathways in borate glasses." Journal of Non-Crystalline Solids 352, no. 42-49 (November 2006): 5164–69. http://dx.doi.org/10.1016/j.jnoncrysol.2006.01.166.
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Proietti, M. G., H. Renevier, S. Grenier, G. Subias, L. Gonzalez, J. M. Garcia, J. L. Hodeau, and J. Garcia. "Diffraction Anomalous Fine Structure for probing local structure: strain, ordering, low dimensionality effects." Acta Crystallographica Section A Foundations of Crystallography 56, s1 (August 25, 2000): s65. http://dx.doi.org/10.1107/s0108767300022121.
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Zhang, Qi, and S. C. Bayliss. "The correlation of dimensionality with emitted wavelength and ordering of freshly produced porous silicon." Journal of Applied Physics 79, no. 3 (February 1996): 1351–56. http://dx.doi.org/10.1063/1.361032.
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King, Graham, Susana Garcia-Martin, Esteban Urones-Garrote, Gwilherm Nenert, and Patrick M. Woodward. "Complex Superstructures Resulting from Compositional Modulation and Octahedral Tilt Twinning in AA′BB′O6 Doubly Cation Ordered Perovskites." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2013, CICMT (September 1, 2013): 000006–13. http://dx.doi.org/10.4071/cicmt-ta13.
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The ordering of cations within the perovskite structure can have a profound effect on the physical properties. A number of AA′BB′O6 perovskite phases which have both a rock salt ordering of the B/B′ cations and a layered ordering of the A/A′ cations have recently been prepared and studied. In some of these compositions complex nanoscale superstructure formation has been observed. These superstructures are the result of compositional modulations involving the occupancies of the A and A′ cations and are accompanied by a twinning of the octahedral tilt system. A wide variety of patterns are observed, such as 1-dimensional stripes or 2-dimensional chessboards which can have periodicities which are either commensurate or incommensurate with the underlying subcell. These superstructures cannot be easily detected by powder X-ray diffraction but have been observed using a combination of high resolution transmission electron microscopy, electron diffraction, and neutron powder diffraction. The factors which determine the dimensionality and periodicity of the superstructures are discussed and compared with the closely related Li based perovskite systems.
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Klimov, S. P., M. V. Mamonova, and Vladimir V. Prudnikov. "Description of Substitutional Adsorption of Magnetic Ions on Metallic Surfaces with Formation of Monolayer Ferromagnetic Films Using the Spin-Density Functional Method." Solid State Phenomena 190 (June 2012): 27–30. http://dx.doi.org/10.4028/www.scientific.net/ssp.190.27.
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At present time, a large number of experimental works have been devoted to the study of magnetic ordering in Fe, Co, and Ni ultrathin films [. The investigation of a nature of magnetism in these structures has a large fundamental interest through an observable dimensionality crossover of magnetic characteristics from three dimensional values for films with thickness d 10 nm to two dimensional values for films with thickness d 1-2 nm. It has been established that the long-range ferromagnetic order arises in films at some effective film thickness. However, the nature and regularities of this phenomenon remain not quite clear. In our paper [ it was developed in terms of the spin-density functional theory the description of influence of the temperature and ferromagnetic ordering on the adsorption of Fe, Co, and Ni transition metal ions on a nonmagnetic substrate with the formation of a submonolayer films. For case of nonactivated adsorption the conditions for the formation of magnetic monoatomic films stable with respect to island adsorption with a change in the coverage parameter θ are revealed. It was demonstrated that the inclusion of the ferromagnetic ordering substantially affects the adsorption energy and leads to its considerable increase.
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Rueff, Jean-Michel, Carley Paulsen, Jean Souletie, Marc Drillon, and Pierre Rabu. "Very-low temperature magnetic ordering and dimensionality of the square planar system cobalt(II) phenoxyacetate." Solid State Sciences 7, no. 4 (April 2005): 431–36. http://dx.doi.org/10.1016/j.solidstatesciences.2005.01.005.
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BOURBONNAIS, CLAUDE, and LAURENT G. CARON. "RENORMALIZATION GROUP APPROACH TO QUASI-ONE-DIMENSIONAL CONDUCTORS." International Journal of Modern Physics B 05, no. 06n07 (April 1991): 1033–96. http://dx.doi.org/10.1142/s0217979291000547.
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We review the recent progress made in the application of the renormalization group method to the interacting quasi-one-dimensional electron gas. From the functional integral formulation of the partition function as expressed in terms of anticommuting Grassmann variables, the effects of single-electron interchain hopping on the mechanisms of propagation of correlations leading to long range ordering is analyzed in full details for the non-half-filled band case. Within a unified formalism, the scaling features of the purely one-dimensional correlations, the dimensionality crossover of both single and composite particles, the critical temperatures, and the responses functions are described.
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Reiman, Derek, Godhev Kumar Manakkat Vijay, Heping Xu, Andrew Sonin, Dianyu Chen, Nathan Salomonis, Harinder Singh, and Aly A. Khan. "Pseudocell Tracer—A method for inferring dynamic trajectories using scRNAseq and its application to B cells undergoing immunoglobulin class switch recombination." PLOS Computational Biology 17, no. 5 (May 3, 2021): e1008094. http://dx.doi.org/10.1371/journal.pcbi.1008094.
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Single cell RNA sequencing (scRNAseq) can be used to infer a temporal ordering of cellular states. Current methods for the inference of cellular trajectories rely on unbiased dimensionality reduction techniques. However, such biologically agnostic ordering can prove difficult for modeling complex developmental or differentiation processes. The cellular heterogeneity of dynamic biological compartments can result in sparse sampling of key intermediate cell states. To overcome these limitations, we develop a supervised machine learning framework, called Pseudocell Tracer, which infers trajectories in pseudospace rather than in pseudotime. The method uses a supervised encoder, trained with adjacent biological information, to project scRNAseq data into a low-dimensional manifold that maps the transcriptional states a cell can occupy. Then a generative adversarial network (GAN) is used to simulate pesudocells at regular intervals along a virtual cell-state axis. We demonstrate the utility of Pseudocell Tracer by modeling B cells undergoing immunoglobulin class switch recombination (CSR) during a prototypic antigen-induced antibody response. Our results revealed an ordering of key transcription factors regulating CSR to the IgG1 isotype, including the concomitant expression of Nfkb1 and Stat6 prior to the upregulation of Bach2 expression. Furthermore, the expression dynamics of genes encoding cytokine receptors suggest a poised IL-4 signaling state that preceeds CSR to the IgG1 isotype.
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Yang, Lina, Hailong Su, Cheng Zhong, Zuqiang Meng, Huiwu Luo, Xichun Li, Yuan Yan Tang, and Yang Lu. "Hyperspectral image classification using wavelet transform-based smooth ordering." International Journal of Wavelets, Multiresolution and Information Processing 17, no. 06 (November 2019): 1950050. http://dx.doi.org/10.1142/s0219691319500504.
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To efficiently improve the accuracy of hyperspectral image (HSI) classification, the spatial information is usually fused with spectral information so that the classification performance can be enhanced. In this paper, we propose a new classification method called wavelet transform-based smooth ordering (WTSO). WTSO consists of three main components: wavelet transform for feature extraction, spectral–spatial based similarity measurement, smooth ordering based 1D embedding, and construction of final classifier using interpolation scheme. Specifically, wavelet transform is first imposed to decompose the HSI signal into approximate coefficients (ACs) and details coefficients (DCs). Then, to measure the similar level of pairwise samples, a novel metric is defined on the ACs, where the spatial information serves as the prior knowledge. Next, according to the measurement results, smooth ordering is applied so that the samples are aligned in a 1D space (called 1D embedding). Finally, since the reordering samples are smooth, the labels of test samples can be recovered using the simple 1D interpolation method. In the last step, in order to reduce the bias and improve accuracy, the final classifier is constructed using multiple 1D embeddings. The use of wavelet transform in WTSO can also reduce the high dimensionality of HSI data. By converting the hight-dimensional samples into a 1D ordering sequence, WTSO can reduce the computational cost, and simultaneously perform classification for the test samples. Note that in WTSO, the smooth ordering based 1D embedding and interpolation are executed in an iterative manner. And they will be terminated after finite steps. The proposed method is experimentally demonstrated on two real HSI datasets: IndianPines and University of Pavia, achieving promising results.
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Herrera-Velarde, Salvador, Edith C. Euán-Díaz, and Ramón Castañeda-Priego. "Ordering and Dynamics of Interacting Colloidal Particles under Soft Confinement." Colloids and Interfaces 5, no. 2 (May 17, 2021): 29. http://dx.doi.org/10.3390/colloids5020029.
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Confinement can induce substantial changes in the physical properties of macromolecules in suspension. Soft confinement is a particular class of restriction where the boundaries that constraint the particles in a region of the space are not well-defined. This scenario leads to a broader structural and dynamical behavior than observed in systems enclosed between rigid walls. In this contribution, we study the ordering and diffusive properties of a two-dimensional colloidal model system subjected to a one-dimensional parabolic trap. Increasing the trap strength makes it possible to go through weak to strong confinement, allowing a dimensional transition from two- to one-dimension. The non-monotonic response of the static and dynamical properties to the gradual dimensionality change affects the system phase behavior. We find that the particle dynamics are connected to the structural transitions induced by the parabolic trap. In particular, at low and intermediate confinement regimes, complex structural and dynamical scenarios arise, where the softness of the external potential induces melting and freezing, resulting in faster and slower particle diffusion, respectively. Besides, at strong confinements, colloids move basically along one direction, and the whole system behaves structurally and dynamically similar to a one-dimensional colloidal system.
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BAHR, CHRISTIAN. "INFLUENCE OF DIMENSIONALITY AND SURFACE ORDERING ON PHASE TRANSITIONS: STUDIES OF FREELY-SUSPENDED LIQUID-CRYSTAL FILMS." International Journal of Modern Physics B 08, no. 22 (October 10, 1994): 3051–82. http://dx.doi.org/10.1142/s0217979294001299.
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Freely-suspended films of smectic liquid crystals can be regarded as membranes consisting of a stack of an integral number of molecular (smectic) layers with the layer planes being parallel to the two free surfaces. Because of their variable thickness (between thousands and only two layers) and the large variety of phase transitions between different smectic phases, freely-suspended films are excellent systems to study the influence of the dimensional cross-over from three to two dimensions on phase transitions. Further, because the free surface of a liquid crystal has a strong ordering effect (contrary to solids which exhibit generally surface-induced disorder), freely-suspended films are well-suited for the study of the effect of enhanced surface order on phase transitions. A review of the corresponding experimental work is given.
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GAMBARDELLA, P., A. DALLMEYER, K. MAITI, M. C. MALAGOLI, W. EBERHARDT, K. KERN, and C. CARBONE. "LONG-RANGE FERROMAGNETIC ORDER IN ONE-DIMENSIONAL MONATOMIC Co-CHAINS." International Journal of Nanoscience 04, no. 05n06 (October 2005): 1029–31. http://dx.doi.org/10.1142/s0219581x05004029.
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Magnetism in low dimensions is a challenging problem for long time. As the dimensionality of the systems reduces, the fluctuations become more important and hence, the magnetic ordering tends to decrease. We find that one-dimensional monatomic chains of Co constructed on a Pt substrate exhibit long-range order below a threshold temperature in contrast to various theoretical results and expectations. The Co -chains have large localized orbital moment compared to that in the two-dimensional films and bulk Co . Therefore, the magnetic anisotropy energy is significantly large in this case. Thus, the observation of long-range ferromagnetic order in Co -chains may be attributed to the presence of anisotropy barriers due to the substrate.
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Bartsch, Timo, Dirk Johrendt, and Rainer Pöttgen. "Dimensionality of the oxidic layers in pnictide oxides and transition metalp-element ordering in tetrelides and pnictides." physica status solidi (b) 254, no. 1 (May 20, 2016): 1600084. http://dx.doi.org/10.1002/pssb.201600084.
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Lin, Chieh, and Ziv Bar-Joseph. "Continuous-state HMMs for modeling time-series single-cell RNA-Seq data." Bioinformatics 35, no. 22 (April 30, 2019): 4707–15. http://dx.doi.org/10.1093/bioinformatics/btz296.
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Abstract Motivation Methods for reconstructing developmental trajectories from time-series single-cell RNA-Seq (scRNA-Seq) data can be largely divided into two categories. The first, often referred to as pseudotime ordering methods are deterministic and rely on dimensionality reduction followed by an ordering step. The second learns a probabilistic branching model to represent the developmental process. While both types have been successful, each suffers from shortcomings that can impact their accuracy. Results We developed a new method based on continuous-state HMMs (CSHMMs) for representing and modeling time-series scRNA-Seq data. We define the CSHMM model and provide efficient learning and inference algorithms which allow the method to determine both the structure of the branching process and the assignment of cells to these branches. Analyzing several developmental single-cell datasets, we show that the CSHMM method accurately infers branching topology and correctly and continuously assign cells to paths, improving upon prior methods proposed for this task. Analysis of genes based on the continuous cell assignment identifies known and novel markers for different cell types. Availability and implementation Software and Supporting website: www.andrew.cmu.edu/user/chiehl1/CSHMM/ Supplementary information Supplementary data are available at Bioinformatics online.
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Sijtsma, Klaas, and L. Andries van der Ark. "Advances in nonparametric item response theory for scale construction in quality-of-life research." Quality of Life Research 31, no. 1 (November 9, 2021): 1–9. http://dx.doi.org/10.1007/s11136-021-03022-w.
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AbstractWe introduce the special section on nonparametric item response theory (IRT) in Quality of Life Research. Starting from the well-known Rasch model, we provide a brief overview of nonparametric IRT models and discuss the assumptions, the properties, and the investigation of goodness of fit. We provide references to more detailed texts to help readers getting acquainted with nonparametric IRT models. In addition, we show how the rather diverse papers in the special section fit into the nonparametric IRT framework. Finally, we illustrate the application of nonparametric IRT models using data from a questionnaire measuring activity limitations in walking. The real-data example shows the quality of the scale and its constituent items with respect to dimensionality, local independence, monotonicity, and invariant item ordering.
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Bassano, Alessio, Vishwanath Kalayani, Lavinia Curecheriu, Maria Buscaglia, Vincenzo Buscaglia, Liliana Mitoseriu, and Paolo Nanni. "Nanoferroelectric perovskite oxides with unusual morphology produced by different synthesis procedures." Processing and Application of Ceramics 4, no. 3 (2010): 147–56. http://dx.doi.org/10.2298/pac1003147b.
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We report in the present paper some original results of a joint research performed in the framework of the COST Action 539 ELENA. In search of higher miniaturisation of electroceramic devices a new outlook seems to arise from ceramics with unusual morphology that might present a new kind of circular or toroidal ferroelectric ordering of dipoles. Completely new perspectives in data storage can be expected if a close control of size confinement and dimensionality as well as of the chemical composition and the phase purity is reached. We succeeded in the fabrication of BaTiO3 hollow nanoparticles and nanowires, and Bi4Ti3O12 platelets. The use of soft chemistry and solid state methods allowed to produce coreshell powders and ferroelectric-ferromagnetic composites with completely new functional properties.
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Santos, Andrés, Franz Saija, and Paolo Giaquinta. "Residual Multiparticle Entropy for a Fractal Fluid of Hard Spheres." Entropy 20, no. 7 (July 23, 2018): 544. http://dx.doi.org/10.3390/e20070544.
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The residual multiparticle entropy (RMPE) of a fluid is defined as the difference, Δs, between the excess entropy per particle (relative to an ideal gas with the same temperature and density), sex, and the pair-correlation contribution, s2. Thus, the RMPE represents the net contribution to sex due to spatial correlations involving three, four, or more particles. A heuristic “ordering” criterion identifies the vanishing of the RMPE as an underlying signature of an impending structural or thermodynamic transition of the system from a less ordered to a more spatially organized condition (freezing is a typical example). Regardless of this, the knowledge of the RMPE is important to assess the impact of non-pair multiparticle correlations on the entropy of the fluid. Recently, an accurate and simple proposal for the thermodynamic and structural properties of a hard-sphere fluid in fractional dimension 1<d<3 has been proposed (Santos, A.; López de Haro, M. Phys. Rev. E 2016, 93, 062126). The aim of this work is to use this approach to evaluate the RMPE as a function of both d and the packing fraction ϕ. It is observed that, for any given dimensionality d, the RMPE takes negative values for small densities, reaches a negative minimum Δsmin at a packing fraction ϕmin, and then rapidly increases, becoming positive beyond a certain packing fraction ϕ0. Interestingly, while both ϕmin and ϕ0 monotonically decrease as dimensionality increases, the value of Δsmin exhibits a nonmonotonic behavior, reaching an absolute minimum at a fractional dimensionality d≃2.38. A plot of the scaled RMPE Δs/|Δsmin| shows a quasiuniversal behavior in the region −0.14≲ϕ−ϕ0≲0.02.
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Le Goff, Xavier F., Stéphanie Willemin, Claude Coulon, Joulia Larionova, Bruno Donnadieu, and Rodolphe Clérac. "[NH4]2Mn3(H2O)4[Mo(CN)7]2·4H2O: Tuning Dimensionality and Ferrimagnetic Ordering Temperature by Cation Substitution." Inorganic Chemistry 43, no. 16 (August 2004): 4784–86. http://dx.doi.org/10.1021/ic049513n.
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Brown, Ted, and Carolyn Unsworth. "Evaluating Construct Validity of the Slosson Visual-Motor Performance Test Using the Rasch Measurement Model." Perceptual and Motor Skills 108, no. 2 (April 2009): 367–82. http://dx.doi.org/10.2466/pms.108.2.367-382.
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The aim of this study was to evaluate the construct validity of the Slosson Visual-Motor Performance Test by applying the Rasch Measurement Model to evaluate the test's scalability, dimensionality, differential item functioning based on sex, and hierarchical ordering. Participants were 400 children ages 5 to 12 years, recruited from six schools in Melbourne, Victoria, Australia. The Slosson Visual-Motor Performance Test requires a child to copy 14 different geometric designs three times each for a total 42 scale items. Children completed the test under the supervision of an occupational therapist. Overall, 13 of 42 of the test items exhibited poor measurement properties. As nearly one-third of the scale items were problematic, the Slosson Visual-Motor Performance Test in its current form is not recommended for clinical use.
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Qaseem, S., M. Naeem, M. Ikram, and Nimra Niamat. "Effect of Reduced Dimensionality on the Magnetic and Transport Properties of Ca Doped Colossal Magnetoresistive Nanoparticles." JOURNAL OF NANOSCOPE (JN) 2, no. 1 (June 30, 2021): 29–38. http://dx.doi.org/10.52700/jn.v2i1.26.
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Magnetic and electrical measurements of different nanosize Ca doped colossal magnetoresistive La0.7Ca0.3MnO3 are reported. The nanoparticles are synthesized with the modified citrate rout at different temperatures. X-ray diffraction measurements revealed three dominant peaks 23.040, 40.5170 .47.170, 58.660 which confirms the perovskite-like structure. The average crystallite size the nanoparticles are found to be 20 to 32nm. All the synthesized nanoparticles exhibit ferromagnetic ordering close to the phase transition temperatures. The size dependent magnetic and electrical transport properties are explored at different fields and temperature. Saturation magnetization is found to decrease with decreasing particle diameter. It is found that the particle size can tune the trend of coercive field. Coercive field first increases from 78 to 210 Oe and then decreases to 174 Oe. The electrical transition temperature is found to be 158 K for 20nm particle. Oxygen deficiency in such system generally reduces Mn4+ to Mn3+ to keep the charge neutrality of the structure and hence it destroys the conduction path ways to mobile electrons, at least in long range, and thus insulating behavior becomes more prominent in the larger temperature range. The trend at lower temperature attribute to the coulomb blockade.
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DIETL, TOMASZ. "DILUTED FERROMAGNETIC SEMICONDUCTORS — ORIGIN OF MAGNETIC ORDERING AND SPIN-TRANSPORT PROPERTIES." International Journal of Modern Physics B 22, no. 01n02 (January 20, 2008): 104–5. http://dx.doi.org/10.1142/s0217979208046116.
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In the first hour of the lecture the present understanding of the origin of exchange interaction and mechanisms leading to ferromagnetic order in diluted magnetic semiconductors will be presented.1 The lecture will start by discussing energy positions of relevant open magnetic shells, including the correlation energy and excitations within the magnetic ions. The origin and magnitude of sp–d exchange interactions will then be described. This will be followed by presenting the physics of indirect exchange interactions between localized spins contrasting magnetic characteristics in the absence and in the presence of free carriers. The Zener and RKKY models of ferromagnetism will be introduced and the role of confinement, dimensionality, and spin-orbit interaction in determining properties of the ferromagnetic phase will be outlined. The second lecture will be devoted to theory of spin transport in layered structures of diluted ferromagnetic semiconductors, emphasizing the issues important for perspective spintronics devices. A recently developed theory,2 which combines a multi-orbital empirical tight-binding approach with a Landauer–Büttiker formalism will be presented. In contrast to the standard kp method, this theory describes properly the interfaces and inversion symmetry breaking as well as the band dispersion in the entire Brillouin zone, so that the essential for the spin-dependent transport Rashba and Dresselhaus terms as well as the tunneling via k points away from the zone center are taken into account. The applicability of this model for the description of tunneling magnetoresistance (TMR), resonant tunneling spectra, spin-current polarization in Esaki-Zener diodes, and domain-wall resistance will be presented. Note from Publisher: This article contains the abstract only.
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Padmaja, Sunkara, Narayanan Ajita, Maddasani Srinivasulu, Sriram Ramchandra Girish, Venkata Gopala Krishna Murthy Pisipati, and Dakshina Murthy Potukuchi. "Crystallization Kinetics in Liquid Crystals with Hexagonal Precursor Phases by Calorimetry." Zeitschrift für Naturforschung A 65, no. 8-9 (September 1, 2010): 733–44. http://dx.doi.org/10.1515/zna-2010-8-916.
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Design and characterization of Schiff based liquid crystalline nO.m compounds exhibiting hexagonal smectic phases are reported. Crystallization kinetics investigations are carried out in the liquid crystals (LCs) exhibiting hexagonal ordered orthogonal and tilted precursor LC phases by calorimetry. The Avrami theory is referred and results are analyzed. Influence of molecular ordering, structure, and dimensionality of the LC precursor phase on kinetics is studied. Effect of shape and flexibility of the molecule for nucleation and growth processes is investigated. Varying rate of kinetics reflects upon the transit of the system from constant type to independent type of nucleation. The trends in the Avrami parameter b and exponent n suggest sporadic nucleation. Crystal growth is interpreted as heterogeneous permeation of layered domains (or aggregates) formed by needle shaped calamitic molecules. Calorimetric observations at different crystallization temperatures CT and hold time t infer diffusion mediated crystallization
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Chitravel, Thangaiyan, Mathukumalli Lakshmi Nasayana Madhu Mohan, and Varadarajan Krishnakumar. "Crystallization Kinetics Study on Orthogonal Ordering in N-(p-n-Alkyoxybenzylidene)-p-n-Alkylanilines (nO.m Compounds) by Thermal and Electrical Techniques. Part I." Zeitschrift für Naturforschung A 64, no. 5-6 (June 1, 2009): 354–60. http://dx.doi.org/10.1515/zna-2009-5-609.
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A systematic kinetic study of crystallization among two smectogens of higher homologues of the benzylidene aniline series nO.m, viz. 4O.12 and 8O.12, has been carried out by thermal microscopy, differential scanning calorimetry (DSC), and dielectric studies. The crystallization kinetics was studied by two techniques, viz. the traditional thermal analysis, i. e. DSC, and electrical studies, i. e. capacitance and dielectric loss variation measurements with temperature. The DSC thermograms were run from the crystallization temperature to the isotropic melting temperature for different time intervals. The liquid crystalline behaviour together with the rate of crystallization of smectic ordering in newly synthesized nO.m compounds were discussed in relation to the kinetophase (which occurs prior to crystallization). The molecular mechanism and dimensionality of crystal growth were computed using the Avrami equation. The characteristic crystallization time (t∗) at each crystallization temperature was deduced from the individual plots of logtand ΔH. Further, it was observed that the data obtained from DSC and dielectric studies were in good agreement.
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Peral, Sergio L., and Madelyn Geldenhuys. "A Rasch Analysis of the Tims, Bakker, and Derks (2012) Job Crafting Scale." Journal of Career Assessment 27, no. 4 (July 16, 2018): 579–93. http://dx.doi.org/10.1177/1069072718788787.
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A Rasch validation was performed on the Tims, Bakker, and Derks’s Job Crafting Scale (JCS) in the South African working context. The JCS, which has been linked to employee well-being and career-related outcomes, continues to be the most widely used measure of job crafting behavior. Data obtained from the JCS generally showed good fit to the Rasch model. Four items were flagged during the analysis for displaying misfit (1 item) or differential item functioning (3 items), warranting further research attention. The study disclosed the dimensionality of the JCS, the hierarchical ordering and fit of the items, the functionality of the response format, and the ability of the JCS to measure invariantly across men and women, yielding new and interesting insights into the psychometric properties of the scale. The study contributes to research concerning the validity of the JCS in a non-European context, particularly through the use of Rasch analysis as a validation technique.
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Abdelhamid, Gomaa S. M., Juana Gómez-Benito, Ahmed T. M. Abdeltawwab, Mostafa H. S. Abu Bakr, and Amina M. Kazem. "A Demonstration of Mokken Scale Analysis Methods Applied to Cognitive Test Validation Using the Egyptian WAIS-IV." Journal of Psychoeducational Assessment 38, no. 4 (July 9, 2019): 493–506. http://dx.doi.org/10.1177/0734282919862144.
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The fourth edition of the Wechsler Adult Intelligence Scale (WAIS-IV) has been used extensively for assessing adult intelligence. This study uses Mokken scale analysis to investigate the psychometric proprieties of WAIS-IV subtests adapted for the Egyptian population in a sample of 250 adults between 18 and 25 years of age. The monotone homogeneity model and the double monotonicity model were consistent with the subtest data. The items of all subtests except Matrix Reasoning, Information, Similarities, and Vocabulary formed a unidimensional scale. The WAIS-IV subtests have discriminatory and invariantly ordered items, although some items violated the invariant item ordering and scalability criteria. Therefore, the WAIS-IV subtests—with the exception of some items—are hierarchical scales that allow items to be ordered according to difficulty and subjects to be ordered using the sum score. In conclusion, the current study provides evidence of the dimensionality and hierarchy of the WAIS-IV subtests in the framework of Mokken scaling, although care should be taken when interpreting or including certain items.
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Krishna Kishore, S., Gudipati Murali, and A. Chandra Mouli. "Building Confidential and Efficient Query Services in the Cloud with RASP Data Perturbation." International Journal of Engineering & Technology 7, no. 3.27 (August 15, 2018): 466. http://dx.doi.org/10.14419/ijet.v7i3.27.17998.
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With the improvement of administrations figuring and distributed computing, it has turned out to be conceivable to outsource extensive databases to database specialist co-ops and let the suppliers keep up the range-inquiry benefit. Nonetheless, a few information may be touchy that the information proprietor does not have any desire to move to the cloud unless the information classification and inquiry security are ensured. We propose the Random Space Encryption (RASP) approach that permits productive range look with more grounded assault versatility than existing proficiency centered methodologies. The arbitrary space irritation (RASP) information annoyance technique to give secure and proficient range question and kNN inquiry administrations for ensured information in the cloud. The RASP information annoyance strategy consolidates arrange protecting encryption, dimensionality development, arbitrary commotion infusion, and irregular projection, to give solid flexibility to assaults on the irritated information and questions. It likewise saves multidimensional reaches, which enables existing ordering systems to be connected to speedup extend question handling. The kNN-R calculation is intended to work with the RASP go inquiry calculation to process the kNNinquiries.
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U, Kumar Siddamallappa, and Dr Nisarg Gandhewar. "Conventional Feature Selection Filter Based Techniques Used in Image Classification." International Journal of Engineering Research in Computer Science and Engineering 9, no. 6 (June 20, 2022): 1–5. http://dx.doi.org/10.36647/ijercse/09.06.art001.
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With the increased volume of unstructured information coming from various sources, image classification has become substantially more applicable. Various image arrangement strategies have been developed. One of the set up issues in image arrangement is the high-dimensionality of element space. Highlight determination is one of the methods to lessen dimensionality. Highlight determination helps in expanding classifier execution, decrease over sifting to accelerate the grouping model development and testing and make models more interpretable. A review of experimental results examining the execution of few element choice methods (Chi-squared, Information Gain, Mutual Data, and Symmetrical Uncertainty) coupled with classifiers such as guileless bayes, SVM, choice tree, and k-NN. The purpose of this paper is to investigate the effects of component determination strategies on different classifiers on image datasets. The concentrate also enables contrasting the general exhibition of the classifiers and techniques. The assessment of element determination techniques for image grouping with little example datasets should think about arrangement execution, dependability, and productivity. It is, consequently, a numerous rule navigation (MCDM) issue. However, there has been little examination in include determination assessment utilizing MCDM techniques that think about various standards. Subsequently, we use MCDM-based strategies for assessing highlight determination techniques for image arrangement with little example datasets. Trial review of five MCDM strategies is intended to compare and contrast the proposed approach with 10 component choice techniques, nine assessment measures for paired characterization, seven assessment measures for multi-class ordering, and three classifiers with 10 little datasets. We propose strategies for highlight determination based on the positioned effects of the five MCDM techniques. This study indicates the effectiveness of the utilized MCDM-based strategy in evaluating highlight determination techniques.
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Magon, Arianna, Gianluca Conte, Federica Dellafiore, Cristina Arrigoni, Irene Baroni, Alice Silvia Brera, Jennifer Avenido, et al. "Nursing Profession Self-Efficacy Scale—Version 2: A Stepwise Validation with Three Cross-Sectional Data Collections." Healthcare 11, no. 5 (March 3, 2023): 754. http://dx.doi.org/10.3390/healthcare11050754.
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Background: The nursing professional self-efficacy scale (NPSES) is one of the most used self-reporting tools for assessing nursing self-efficacy. Its psychometric structure was described differently in several national contexts. This study aimed to develop and validate version 2 of the NPSES (NPSES2), which is a brief version of the original scale selecting items that contribute to stably detecting attributes of care delivery and professionalism as descriptors of salient aspects of the nursing profession. Methods: Three different and subsequent cross-sectional data collections were employed to reduce the number of items to generate the NPSES2 and validate its new emerging dimensionality. The first (June 2019–January 2020) involved 550 nurses and was used to reduce the number of the original scale items by using a Mokken scale analysis (MSA) to ensure the selection of items consistently with the invariant item ordering properties. The subsequent data collection was performed to conduct an exploratory factor analysis (EFA) involving 309 nurses (September 2020–January 2021), and the last data collection (n = 249) was performed to cross-validate with a confirmatory factor analysis (CFA), the most plausible dimensionality derived from the EFA (June 2021–February 2022). Results: The MSA led to the removal of twelve items and retention of seven items (Hs = 0.407, standard error = 0.023), which showed adequate reliability (rho reliability = 0.817). The EFA showed a two-factor solution as the most plausible structure (factors loading ranged from 0.673 to 0.903; explained variance = 38.2%), which was cross-validated by the CFA that showed adequate fit indices: χ2 (13, N = 249) = 44.521, p < 0.001; CFI = 0.946; TLI = 0.912; RMSEA = 0.069 (90% CI = 0.048–0.084); SRMR = 0.041. The factors were labeled as care delivery (four items) and professionalism (three items). Conclusions: NPSES2 is recommended to allow researchers and educators to assess nursing self-efficacy and inform interventions and policies.
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Lee, Shih-Hui, Kee-Jiar Yeo, and Lina Handayani. "Development and validation of a sexual and reproductive health knowledge scale." International Journal of Public Health Science (IJPHS) 11, no. 3 (September 1, 2022): 815. http://dx.doi.org/10.11591/ijphs.v11i3.21570.
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The purpose of this study was to develop a reliable and valid instrument to measure primary school students’ sexual and reproductive health (SRH) knowledge. The instrument measures primary school students’ knowledge in four domains: i) puberty; ii) human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) and sexually transmitted diseases; iii) prevention of child sexual abuse; and iv) reproduction and reproductive systems. All items in the instrument were reviewed and screened by experts before they were administered to 125 primary five students. The instrument’s dimensionality, fit statistics, hierarchical ordering of item difficulty, and item and person separation reliability were assessed using the rasch measurement model (RMM). The results showed that the instrument demonstrated unidimensionality, and the items exhibited a wide range of difficulty level. Misfitting items were removed from the questionnaire, and the remaining 36 items were retained. The RMM outputs showed good item’s reliability (.97) with high separation index (5.52). However, the person reliability (.79) and the person separation index (1.94) were slightly the recommended value. Overall, the results show that the developed instrument can be used with confidence to assess sexual and reproductive health (SRH) knowledge among primary school students in Malaysia.
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Gaubatz, Kurt Taylor. "Intervention and Intransitivity: Public Opinion, Social Choice, and the Use of Military Force Abroad." World Politics 47, no. 4 (July 1995): 534–54. http://dx.doi.org/10.1017/s0043887100015203.
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This article argues that the problems identified in the literature on public choice should critically affect our research on public opinion and our understanding of the impact of public opinion on foreign policy. While a robust literature has emerged around social choice issues in political science, there has been remarkably little appreciation for these problems in the literature on public opinion in general and on public opinion and foreign policy in particular. The potential importance of social choice problems for understanding the nature and role of public opinion in foreign policy making is demonstrated through an examination of American public attitudes about military intervention abroad. In particular, drawing on several common descriptions of the underlying dimensionality of public attitudes on major foreign policy issues, it is shown that there may be important intransitivities in the ordering of public preferences at the aggregate level on policy choices such as those considered by American decision makers in the period leading up to the Gulf War. Without new approaches to public-opinion polling that take these problems into consideration, it will be difficult to make credible claims about the role of public opinion in theforeignpolicy process.
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Lu, Binchun, Lidan Fu, Bo Nie, Zhiyun Peng, and Hongying Liu. "A Novel Framework with High Diagnostic Sensitivity for Lung Cancer Detection by Electronic Nose." Sensors 19, no. 23 (December 3, 2019): 5333. http://dx.doi.org/10.3390/s19235333.
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The electronic nose (e-nose) system is a newly developing detection technology for its advantages of non-invasiveness, simple operation, and low cost. However, lung cancer screening through e-nose requires effective pattern recognition frameworks. Existing frameworks rely heavily on hand-crafted features and have relatively low diagnostic sensitivity. To handle these problems, gated recurrent unit based autoencoder (GRU-AE) is adopted to automatically extract features from temporal and high-dimensional e-nose data. Moreover, we propose a novel margin and sensitivity based ordering ensemble pruning (MSEP) model for effective classification. The proposed heuristic model aims to reduce missed diagnosis rate of lung cancer patients while maintaining a high rate of overall identification. In the experiments, five state-of-the-art classification models and two popular dimensionality reduction methods were involved for comparison to demonstrate the validity of the proposed GRU-AE-MSEP framework, through 214 collected breath samples measured by e-nose. Experimental results indicated that the proposed intelligent framework achieved high sensitivity of 94.22%, accuracy of 93.55%, and specificity of 92.80%, thereby providing a new practical means for wide disease screening by e-nose in medical scenarios.
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Mastrippolito, Dario, Jing Wang, Gianni Profeta, and Luca Ottaviano. "Unconventional ferrimagnetism and enhanced magnetic ordering temperature in monolayer CrCl3 by introducing O impurities and Cl vacancies." Journal of Physics: Materials 5, no. 1 (January 1, 2022): 014004. http://dx.doi.org/10.1088/2515-7639/ac5dcd.
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Abstract Among chromium trihalides, a specific group of layered van der Waals magnetic materials, chromium trichloride (CrCl3) is the only system relatively stable under ambient conditions. This is also observed in reduced dimensionality where the emergence of extrinsic long-range ordered oxidized and Cl-vacancy-defective CrCl3 phases is experimentally reported. In this work, the magnetic properties of such two-dimensional (2D) systems are studied using density functional theory (DFT) calculations, including the electron-electron (U) repulsion interactions, and Monte Carlo (MC) simulations. Once the Cl vacancies are introduced, the results indicate that the monolayer CrCl3 has a magnetic moment that is enhanced linearly (up to 3.14 µ B /Cr) in the (1%–10%) vacancy concentration range. This determines a strengthening of the ferromagnetic state and a two-fold increase of the Curie temperature (up to 146 K) as valuated from MC simulations. More interestingly, once oxygen extrinsic impurities are considered, the monolayer CrCl3 structure is hybridized forming a stable ordered phase (O–CrCl3) with oxygen atoms allocated on the Cr atomic layer in the center of the honeycomb ring formed by Cr atoms. The magnetic moments of the O–CrCl3 system are localized on both Cr and O atoms, with oxygen antiferromagnetically coupled to chromium, resulting in a 2D ferrimagnetic hexagonal lattice system with an average magnetic moment of 2.14 µ B /Cr and a high magnetic ordering temperature (110 K) predicted with DFT in the mean field approach.
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Sepulveda, Jorge L., and Donald S. Young. "The Ideal Laboratory Information System." Archives of Pathology & Laboratory Medicine 137, no. 8 (August 1, 2013): 1129–40. http://dx.doi.org/10.5858/arpa.2012-0362-ra.
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Context.—Laboratory information systems (LIS) are critical components of the operation of clinical laboratories. However, the functionalities of LIS have lagged significantly behind the capacities of current hardware and software technologies, while the complexity of the information produced by clinical laboratories has been increasing over time and will soon undergo rapid expansion with the use of new, high-throughput and high-dimensionality laboratory tests. In the broadest sense, LIS are essential to manage the flow of information between health care providers, patients, and laboratories and should be designed to optimize not only laboratory operations but also personalized clinical care. Objectives.—To list suggestions for designing LIS with the goal of optimizing the operation of clinical laboratories while improving clinical care by intelligent management of laboratory information. Data Sources.—Literature review, interviews with laboratory users, and personal experience and opinion. Conclusions.—Laboratory information systems can improve laboratory operations and improve patient care. Specific suggestions for improving the function of LIS are listed under the following sections: (1) Information Security, (2) Test Ordering, (3) Specimen Collection, Accessioning, and Processing, (4) Analytic Phase, (5) Result Entry and Validation, (6) Result Reporting, (7) Notification Management, (8) Data Mining and Cross-sectional Reports, (9) Method Validation, (10) Quality Management, (11) Administrative and Financial Issues, and (12) Other Operational Issues.
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Fernández-Martínez, Juan Luis, Zulima Fernández-Muñiz, Shan Xu, Ana Cernea, Colette Sirieix, and Joëlle Riss. "Efficient uncertainty analysis of the 3D electrical tomography inverse problem." GEOPHYSICS 84, no. 3 (May 1, 2019): E209—E223. http://dx.doi.org/10.1190/geo2017-0729.1.
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We have evaluated the uncertainty analysis of the 3D electrical tomography inverse problem using model reduction via singular-value decomposition and performed sampling of the nonlinear equivalence region via an explorative member of the particle swarm optimization (PSO) family. The procedure begins with the local inversion of the observed data to find a good resistivity model located in the nonlinear equivalence region. Then, the dimensionality is reduced via the spectral decomposition of the 3D geophysical model. Finally, the exploration of the uncertainty space is performed via an exploratory version of PSO (RR-PSO). This sampling methodology does not prejudge where the initial model comes from as long as this model has a geologic meaning. The 3D subsurface conductivity distribution is arranged as a 2D matrix by ordering the conductivity values contained in a given earth section as a column array and stacking parallel sections as columns of the matrix. There are three basic modes of ordering: mode 1 and mode 2, by using vertical sections in two perpendicular directions, and mode 3, by using horizontal sections. The spectral decomposition is then performed using these three 2D modes. Using this approach, it is possible to sample the uncertainty space of the 3D electrical resistivity inverse problem very efficiently. This methodology is intrinsically parallelizable and could be run for different initial models simultaneously. We found the application to a synthetic data set that is well-known in the literature related to this subject, obtaining a set of surviving geophysical models located in the nonlinear equivalence region that can be used to approximate numerically the posterior distribution of the geophysical model parameters (frequentist approach). Based on these models, it is possible to perform the probabilistic segmentation of the inverse solution found, meanwhile answering geophysical questions with its corresponding uncertainty assessment. This methodology has a general character could be applied to any other 3D nonlinear inverse problems by implementing their corresponding forward model.
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Dür, Mona, Anna Röschel, Christiane Oberleitner-Leeb, Verena Herrmanns, Elisabeth Pichler-Stachl, Barbara Mattner, Silvia-Desiree Pernter, et al. "Development and validation of a self-reported questionnaire to assess occupational balance in parents of preterm infants." PLOS ONE 16, no. 11 (November 15, 2021): e0259648. http://dx.doi.org/10.1371/journal.pone.0259648.
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Background Parents’ meaningful activities (occupations) and occupational balance are relevant to neonatal care. Valid and reliable self-reported measurement instruments are needed to assess parents’ occupational balance and to evaluate occupational balance interventions in neonatal care. The aims of this study were to develop a self-reported questionnaire on occupational balance in informal caregivers (OBI-Care) and to examine its measurement properties including construct validity and internal consistency. Methods and findings A mixed method multicenter study design was employed. Items of the OBI-Care were created with parents of preterm infants based on qualitative research methods. Measurement properties were analyzed with quantitative data of parents of preterm infants. Construct validity was assessed by determining dimensionality, overall and item fit to a Rasch model, differential item functioning and threshold ordering. Internal consistency was examined by determining inter-item and item-total correlations, Cronbach’s alpha and Rasch’s person separation index. Fourteen parents participated in item creation. Measurement properties were explored in data of 304 parents. Twenty-two items, summarized in three subscales were compiled to the OBI-Care. Items showed an overall fit and except one item, an item fit to the Rasch model. There was no evidence of differential item functioning and all items displayed ordered thresholds. Each subscale had good values of person separation indices and Cronbach’s alpha. Conclusions The OBI-Care demonstrates construct validity and internal consistency and is thus a suitable measurement instrument to assess occupational balance of parents of preterm infants in neonatal care. OBI-Care is generic and can be applied in various health care settings.
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Röschel, Anna, Christina Wagner, and Mona Dür. "Examination of validity, reliability, and interpretability of a self-reported questionnaire on Occupational Balance in Informal Caregivers (OBI-Care) – A Rasch analysis." PLOS ONE 16, no. 12 (December 23, 2021): e0261815. http://dx.doi.org/10.1371/journal.pone.0261815.
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Objectives Informal caregivers often experience a restriction in occupational balance. The self-reported questionnaire on Occupational Balance in Informal Caregivers (OBI-Care) is a measurement instrument to assess occupational balance in informal caregivers. Measurement properties of the German version of the OBI-Care had previously been assessed in parents of preterm infants exclusively. Thus, the aim of this study was to examine the measurement properties of the questionnaire in a mixed population of informal caregivers. Methods A psychometric study was conducted, applying a multicenter cross-sectional design. Measurement properties (construct validity, internal consistency, and interpretability) of each subscale of the German version of the OBI-Care were examined. Construct validity was explored by assessing dimensionality, item fit and overall fit to the Rasch model, and threshold ordering. Internal consistency was examined with inter-item correlations, item-total correlations, Cronbach’s alpha, and person separation index. Interpretability was assessed by inspecting floor and ceiling effects. Results A total of 196 informal caregivers, 171 (87.2%) female and 25 (12.8%) male participated in this study. Mean age of participants was 52.27 (±12.6) years. Subscale 1 was multidimensional, subscale 2 and subscale 3 were unidimensional. All items demonstrated item fit and overall fit to the Rasch model and displayed ordered thresholds. Cronbach’s Alpha and person separation index values were excellent for each subscale. There was no evidence of ceiling or floor effects. Conclusions We identified satisfying construct validity, internal consistency, and interpretability. Thus, the findings of this study support the application of the German version of the OBI-Care to assess occupational balance in informal caregivers.
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Xu, Jianjun, and Lanlan Cao. "Optimal in-store inventory policy for omnichannel retailers in franchising networks." International Journal of Retail & Distribution Management 47, no. 12 (December 9, 2019): 1251–65. http://dx.doi.org/10.1108/ijrdm-09-2018-0199.
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Purpose The purpose of this paper is to characterize the optimal ordering and allocation policy for a store replenishment decision in the context of an omnichannel retailer in a franchise network. The authors further show that a myopic policy is optimal, which circumvents the curse of dimensionality for the multi-period inventory model and help store managers optimize their decisions about the amount of inventory to stock for both online and offline demands and the percentage of inventory to reserve for online orders. Design/methodology/approach This research is trigged by several managerial studies which suggest reserving a certain percentage of the in-store inventory for online orders as a good store inventory allocation practice for omnichannel retailers in a franchise network. The authors used an analytical model to develop this practice by clarifying how store managers can decide on the amount of inventory to replenish and the percentage to reserve for online orders. Findings This study develops a finite horizon, periodic review inventory model to identify an optimal and dynamic replenishment and allocation policy. The analysis uncovers the system’s fundamental structural property concavity. The research shows that, due to this property, the optimal replenishment policy is a base-stock policy. The latter is due to the base stock level being independent of the initial inventory at hand, and the optimal allocation level being non-decreasing on the base-stock level. Research limitations/implications This study contributes to the literature on store inventory management for omnichannel retailers in a franchise network by investigating their optimal store inventory ordering and allocation policy. Nevertheless, the zero-lead time and zero-setup cost assumptions limit the findings. Practical implications Insights into an optimal store inventory policy may guide franchisee store managers to decide on the amount of inventory to replenish and the percentage to reserve for online orders. Originality/value The originality of this paper lies in its focus on in-store inventory management for omnichannel retailers in a franchise network. The findings are helpful for franchisor retailers to implement the omnichannel strategy at the level of in-store inventory management. Beyond using incentive systems, the franchisor should leverage legitimate powers by mentioning a relevant measure in their contracts with their franchisee to minimize their channel conflicts and ensure their customers have seamless shopping experiences.
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Romanenko, A. I., G. E. Chebanova, Tingting Chen, Wenbin Su, and Hongchao Wang. "Review of the thermoelectric properties of layered oxides and chalcogenides." Journal of Physics D: Applied Physics 55, no. 14 (December 3, 2021): 143001. http://dx.doi.org/10.1088/1361-6463/ac3ce6.
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Abstract The current state of investigation on thermoelectric properties of layered chalcogenides and oxides is considered. The relationship between the quasi-two-dimensionality of electronic transport properties and thermoelectric properties is confirmed. A decrease in the dimension of electron transport from three-dimensional to quasi-two-dimensional in materials with a layered structure increases the thermopower with a slight change in electrical conductivity. The bismuth tellurides, bismuth selenides and its alloys are currently one of the outstanding state of the art bulk thermoelectric materials with layered structure. Layered transition metal dichalcogenides MX2 (M is a transition metal, X is a chalcogen) are efficient thermoelectric materials at higher temperatures (500–800 K). In these materials, an increase in thermoelectric properties associated with the two-dimensionalization of electron transport is also observed. Layered monochalcogenides MX (M = Sn, Pb, Ge; X = S, Se, Te) are also a promising class of thermoelectric materials. In SnSe single crystals, Z T ∼ 2.6 is obtained at 923 K due to the very low thermal conductivity along the b axis (0.23 W (m K)−1 at 973 K). Layered chalcogenides CuCrX2 (X = S, Se, Te) containing magnetic Cr atoms are effective thermoelectrics at higher temperatures (up to 800 K) due to the presence of phonon glass–electron crystal state led to a significant decrease in thermal conductivity at high temperatures. Magnetic atoms in CuCrX2 compounds lead to the presence of magnetic phase transitions affecting their thermoelectric properties. Interest in oxide-based thermoelectric materials has significantly increased due to their stability in air and higher temperatures for maximum efficiency. The most promising thermoelectric oxide materials Ca3Co4O9, Na x CoO2, Bi2Ca2Co2O x , and CaCo2O4 have a layered structure and contain magnetic Co atoms leading to magnetic ordering and influence on thermoelectric properties. The presence of phase transitions affects the thermoelectric parameters of thermoelectrics and the thermoelectric figure of merit ZT.
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Argyriou, D. N., J. F. Mitchell, J. D. Jorgensen, J. B. Goodenough, P. G. Radaelli, D. E. Cox, and H. N. Bordallo. "Structure and Magnetism in the Layered CMR Manganites La2-2xSr1+2xMn2O7 (x= 0·3, 0·4)." Australian Journal of Physics 52, no. 2 (1999): 279. http://dx.doi.org/10.1071/p98105.
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In this paper we describe a detailed neutron diffraction investigation of the crystal and magnetic structure of two layered CMR manganites La1·2Sr1·8Mn2O7 (x = 0·4) and La1·4Sr1·6Mn2O7 (x = 0·3). In these materials of reduced dimensionality compared to the 3D perovskites, we find competing effects between charge-lattice and spin degrees of freedom. These effects can be investigated by studying the behaviour of crystal and magnetic structure as a function of temperature, composition and hydrostatic pressure. We find opposite lattice responses to the onset of charge delocalisation and magnetic ordering in these two layered compounds. Below the insulator-to-metal transition (TIM), the lattice response suggests that charge is transferred to d3z2-r2 orbitals in La1·2Sr1·8Mn2O7 and to dx2-y2 orbitals in La1·4Sr1·6Mn2O7. We argue that these changes are too large to be due to chemical differences. Instead we suggest that the orbital configuration of the Mn ion below TIM is sensitive to electronic doping. In La1·2Sr1·8Mn2O7 we find that the lattice response at TIM to be driven by lattice displacements that relax below TIM, consistent with polaronic degrees of freedom. We also note that the competition between super- and double-exchange to be significant in reduced dimensions. This is manifested in the change in the sign of the apical Mn-O bond compressibilities above and below TIM. Finally, we describe the magnetic structure of these two different layered manganites. We find that electronic doping also results in significant changes to the ordered arrangement of Mn spins. Interestingly the magnetism in reduced dimensions in these materials can be varied from relative simple structures that show ferromagnetic inter-bilayer coupling as observed in La1·2Sr1·8Mn2O7 to structures with antiferromagnetic inter-bilayer coupling as found in La1·4Sr1·6Mn2O7.
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Siena, Martina, Alberto Guadagnini, Ernesto Della Rossa, Andrea Lamberti, Franco Masserano, and Marco Rotondi. "A Novel Enhanced-Oil-Recovery Screening Approach Based on Bayesian Clustering and Principal-Component Analysis." SPE Reservoir Evaluation & Engineering 19, no. 03 (March 9, 2016): 382–90. http://dx.doi.org/10.2118/174315-pa.
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Summary We present and test a new screening methodology to discriminate among alternative and competing enhanced-oil-recovery (EOR) techniques to be considered for a given reservoir. Our work is motivated by the observation that, even if a considerable variety of EOR techniques was successfully applied to extend oilfield production and lifetime, an EOR project requires extensive laboratory and pilot tests before fieldwide implementation and preliminary assessment of EOR potential in a reservoir is critical in the decision-making process. Because similar EOR techniques may be successful in fields sharing some global features, as basic discrimination criteria, we consider fluid (density and viscosity) and reservoir-formation (porosity, permeability, depth, and temperature) properties. Our approach is observation-driven and grounded on an exhaustive database that we compiled after considering worldwide EOR field experiences. A preliminary reduction of the dimensionality of the parameter space over which EOR projects are classified is accomplished through principal-component analysis (PCA). A screening of target analogs is then obtained by classification of documented EOR projects through a Bayesian-clustering algorithm. Considering the cluster that includes the EOR field under evaluation, an intercluster refinement is then accomplished by ordering cluster components on the basis of a weighted Euclidean distance from the target field in the (multidimensional) parameter space. Distinctive features of our methodology are that (a) all screening analyses are performed on the database projected onto the space of principal components (PCs) and (b) the fraction of variance associated with each PC is taken as weight of the Euclidean distance that we determine. As a test bed, we apply our approach on three fields operated by Eni. These include light-, medium-, and heavy-oil reservoirs, where gas, chemical, and thermal EOR projects were, respectively, proposed. Our results are (a) conducive to the compilation of a broad and extensively usable database of EOR settings and (b) consistent with the field observations related to the three tested and already planned/implemented EOR methodologies, thus demonstrating the effectiveness of our approach.
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Rhee, Do Kyung, and Pil J. Yoo. "Interconnected assembly of ZrO2@SiO2 nanoparticles with dimensional selectivity and refractive index tunability." Journal of Materials Chemistry C 7, no. 27 (2019): 8176–84. http://dx.doi.org/10.1039/c9tc02530h.
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A synchronized synthetic method for sequentially inducing the assembly of primary nanoparticles and subsequent shell coating is proposed, eventually implementing dimensionally controlled 1D, 2D, or 3D ordering of nanoparticles.
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Silva, Nilton Correia da, Osmar Abílio de Carvalho Júnior, Antonio Nuno de Castro Santa Rosa, Renato Fontes Guimarães, and Roberto Arnaldo Trancoso Gomes. "CHANGE DETECTION SOFTWARE USING SELF-ORGANIZING FEATURE MAPS." Revista Brasileira de Geofísica 30, no. 4 (December 1, 2012): 505. http://dx.doi.org/10.22564/rbgf.v30i4.237.
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Os mapas auto-organizáveis (SOFM) consistem em um tipo de rede neural artificial que permite a conversão de dados de alta dimensão, complexos e não lineares, em simples relações geométricas com baixa dimensionalidade. Este método também pode ser utilizado para a classificação de imagens de sensoriamento remoto, pois permite a compressão de dados de alta dimensão preservando as relações topológicas dos dados primários. Este trabalho objetiva desenvolver uma metodologia eficaz para a utilização de mapas auto-organizáveis na detecção de mudanças. No presente estudo o SOFM é utilizado para a classificação não supervisionada de dados de sensoriamento remoto, considerando os seguintes atributos: espaciais (x, y), espectrais e temporais. O método é empregado na região oeste da Bahia, que teve recentemente um aumento significativo em monoculturas. Testes foram realizados com os parâmetros do SOFM com o objetivo de refinar o mapa de detecção demudanças. O SOFM possibilita uma melhor seleção de células e dos correspondentes vetores de peso, que mostram o processo de ordenação e agrupamento hierárquicodos dados. Esta informação é essencial para identificar mudanças ao longo do tempo. Um programa em linguagem C ++ do método proposto foi desenvolvido. ABSTRACT. Self-organizing feature maps (SOFM) consist of a type of artificial neural network that allows the conversion from high-dimensional data into simple geometric relationships with low-dimensionality. This method can also be used for classification of remote sensing images because it allows the compression of high dimensional data while preserving the most important topological and metric relationships of the primary data. This paper aims to develop an effective methodology forusing self-organizing maps in change detection. In this study, SOFM is used for unsupervised classification of remote sensing data, considering the following attributes: spatial (x and y), spectral and temporal. The method is tested and simulated in the western region of Bahia that has observed a significant increase in mechanized agriculture. Tests were performed with the SOFM parameters for the purpose of fine tuning a change detection map. The SOFM provides the best selection of cell and corresponding adjustment of weight vectors, which show the process of ordering and hierarchical clustering of the data. This information is essential to identify changes over time. All algorithms were implemented in C++ language.Keywords: unsupervised classification; land cover; multitemporal analysis; remote sensing